Title of Invention	A SYSTEM FOR PRECISION ANGULAR MOTION MECHANISM FOR ALIGNMENT AND POSITIONING OF OPTICAL ELEMENTS
Abstract	A system for precision angular motion mechanism for alignment and positioning of optical elements comprising: a linkage mechanism adapted for constrained angular motion comprising (a) fixed frame link (b) rotatable link (c) linearly variable link and (d) link to position the micrometer head at required angle, wherein the said mechanism the rotatable link forms a turning pair with the fixed frame link while another turning pair is between the fixed frame link and the link that positions the micrometer head at the required angle, linearly variable link adapted to operate on a screw pair and is connected to the rotatable link via micrometer end connector with a self-aligning bearing, the linear motion imparted to the micrometer head adapted to be transferred to the rotating link through self-aligning bearing connected to the micrometer head by means of an end connector such that the mechanism produces precision angular motion through turning pair-screw pair and self-aligning bearing combination.

Title of Invention

A SYSTEM FOR PRECISION ANGULAR MOTION MECHANISM FOR ALIGNMENT AND POSITIONING OF OPTICAL ELEMENTS

Abstract

A system for precision angular motion mechanism for alignment and positioning of optical elements comprising: a linkage mechanism adapted for constrained angular motion comprising (a) fixed frame link (b) rotatable link (c) linearly variable link and (d) link to position the micrometer head at required angle, wherein the said mechanism the rotatable link forms a turning pair with the fixed frame link while another turning pair is between the fixed frame link and the link that positions the micrometer head at the required angle, linearly variable link adapted to operate on a screw pair and is connected to the rotatable link via micrometer end connector with a self-aligning bearing, the linear motion imparted to the micrometer head adapted to be transferred to the rotating link through self-aligning bearing connected to the micrometer head by means of an end connector such that the mechanism produces precision angular motion through turning pair-screw pair and self-aligning bearing combination.

Full Text	FORM 2 THE PATENT ACT 1970 (39 OF 1970) & The Patent Rules, 2003 COMPLETE SPECIFICATION (See section 10 and rule 13) 1 TITLE OF THE INVENTION : A SYSTEM FOR PRECISION ANGULAR MOTION MECHANISM FOR ALIGNMENT AND POSITIONING OF OPTICAL ELEMENTS 2 APPLICANT (S) Name Nationality Address : THE SECRETARY, DEPARTMENT OF ATOMIC ENERGY : An Indian Government Department Govt, of India, Anushakti Bhavan, Chatrapati Shivaji Maharaj Marg,Mumbai 400039, Maharastra, India. 3 PREAMBLE TO THE DESCRIPTION COMPLETE The following specification particularly descibes the invention and the manner in which it is to be performed: 27NOV 2006 FIELD OF THE INVENTION The present invention relates to a system for producing constrained angular motion and, in particular, to a system for precision angular motion mechanism for alignment and positioning of optical elements using a selective combination of turning pair-screw pair and self aligning ball-bearing. The system is specifically adapted for use in precision angular motion mechanism when the output is monitored (photon detectors or interference patterns) such as monochromators in hard X-ray and positioning devices in various visible optical setups. The system is also adapted for angular positioning of optical elements when it is calibrated, also in miniature and large angular stages with fine resolutions in different mechanical applications. The invention also relates to a small sized translation stage involving micrometer head such that the combination of the angular and translation stages is small sized, having good resolution and range and is less weight and cost effective. The system is compact, user-friendly and also cost-effective for wide scale use /application BACKGROUND ART The provision of mechanism for use in angular positioning of optical elements is well known. Conventional devices and mechanisms known for such angular positioning of optical elements include: Worm and gear driven goniometers, which produce fine resolutions when worm rotates a gear. Gear ratio determines the magnitude of such resolution. Many commercial designs, which work on this principle are also available. (Foundations of mechanical accuracy Moore special tool company, Library of Congress Catalogue No. - 73-127307) Micrometers used push an extended rod in swivel stages having arc shaped crossed roller guide to produce constraint angular motion is also known. Such system is commercially made available by M/s Kohzu Precision Company Limited Item No. -ST05A-SIT and the complete series. 2 Standard sine-bar mechanism and its applications are also known wherein micrometer pushes a sine-bar to produce angle. Tiwari M.K., Gowri Sankar B., Raghuvanshi V.K., Nandedkar R.V. and Sawhney KJ.S. "Development of total reflection X-ray fluorescent spectrometer for ultra trace analysis Bull Mater. Sci. Vol 25 No. 5, October 2002, pp435-441. It is also known in the art to provide variety of mirror tilt mounts using screws and spring force. US 3814365 disclose an adjustable mount for rotatably orienting a structure such as an optical element, about two orthogonal axes comprising first and second orthogonal cross-spring pivots and respectively associated first and second coarse fine adjustment mechanism. Each cross spring pivots includes a first member and a second member which is rotatable relative to the first member, these two members being connected by first and second interleaved flat leaf springs which intersects along the respective axes of rotation. Application of a torque of a second member, which has the optical element, mounted thereon, causes rotation thereof relative to the first member about the axis of rotation. Utilizing at least five interleaved spring portions provide substantially improved mechanical stability. US 5019837 discloses a mirror mounting structure with low thermal drift which is enabled by providing a mirror mounting structure which vertically and/or horizontally aligns the mirror by providing two point forces against the mirror holding structure. The mirror holding arm is connected to a thick more rigid arm by resilient narrow slightly flexible neck portion. Screws threaded through the large arm contact alignment points on the mirror mount portion and permit accurate alignment in a desired plane. Thermal drift and hysteresis is minimized since the alignment forces are acting upon the mirror mount portion in the same direction and minimize the deviations caused by thermal expansion. It is also known to achieve angular positioning of optical elements by way of three point adjustments using screws. One of the screws is rotated to get the desired tilt. Likewise four point adjustments are also proposed in the art. 3 While the above state of the art reveal the knowledge prevailing in the art on the provision of variety of devices / mechanisms for angular positioning of optical elements, however, such known mechanisms /devices are found to have some inherent limitation/drawbacks. The drawbacks associated with the known systems include the following: i) Construction of precise goniometer requires accurate fabrication of worm and gears. The processes thus require special purpose machines and metrology. Such factors usually tend to increase the cost of the optical positioning device. ii) The Micrometer push driven stages which is provided with arc shaped cross roller guides have less range of ~±3°. iii) It is also known to use inexpensive alternative to goniometer by use of precise linear drives (such as Micrometer head) and convert it into angular motion. In the same principle sine-bar mechanism also works. Importantly while the sine-bar mechanism can also be efficiently used for precise motions, but such mechanism involves spring loading or gravity returns and is found to be not stable when mounted on other parts rotating about horizontal axis. iv) Importantly it is found that various springs used in optical tilt mounts cause problems in stable optics especially when these mounts are mounted on another rotating part of high precision system. Also angular adjustments introduce some linear variation of optical elements along with rotation because optical elements are mounted away from pivot (axis of rotation do not pass through the reflecting surface of optical elements). Similar problems persist in the US 3814365. v) Angular adjustments using two point forces using screws against resilient neck portion of the structure that allows elastic deformation is a design meant for stable mirror mounting with low thermal drift. This design does not provide continuous variation of angle with good resolution and range using a single input, which is a problem in using them as optical rotational stages. vi) Also three point and four point adjustable mechanisms usually do not provide completely constrained angular motion about a single axis. Also 4 angular motion is found to cause some linear displacement of optical elements. OBJECTS OF THE INVENTION It is thus the basic object of the present invention to provide for a system for precision and constrained angular motion about single axis of rotation at any orientation using linear drives along with possible translation drive to preciously position the optical element involving independent linear and angular motions involving mechanism comprising selectively of turning pair, screw pair and self-aligning bearings without the need for spring returns. Another object of the present invention is to provide a system for precision and constrained angular motion for alignment and positioning of optical elements comprising selectively features including fine resolution, good range and repeatability, self locking, less weight, small size and cost effective. Another object of the present invention is to provide a system for precision and constrained angular motion adapted for use as exit arm monochromator stage of hard X-ray diffractometer for settling the required angle of monochromator. A further object of the present invention is to provide precision angular motion mechanism for alignment and positioning of optical elements which can be carried out using linear drive and would favour stable angular positioning and alignment stages. Yet further object of the present invention is to provide constrained angular motion stages of different sizes depending upon the end use/application. Another object of the present invention is directed to provide a system for angular positioning and alignment for optical elements, which would be cost effective for constructing precision stages without the use of worm and gear. A further object of the present invention is directed to provide for a small sized translation stage involving micrometer head such that the combination of the 5 2 1 MAR 2007 angular and translation stages is small sized, provide good resolution and range and is less weight and cost effective. Another object of the invention is to provide a selective end connector connection there between a micrometer head and ball bearing which would favour direct coupling of the micrometer head to the ball bearing and also provide an end connector based feed in translation stages without need of spring returns as well as construction of open-ended micrometer clamp type rotation stages without need of spring returns. Yet further object of the present invention is directed to provide a system for constrained angular motion for alignment and positioning of optical elements where by the connector would be adapted to allow constructing of hinged and micrometer feed angular motion stages without use of spring returns. SUMMARY OF THE INVENTION Thus according to the basic aspect of the present invention there is provided a system for precision angular motion mechanism for alignment and positioning of optical elements comprising: a linkage mechanism adapted for constrained angular motion comprising (a) fixed frame link (b) rotatable link (c) linearly variable link and (d) link to position the micrometer head at required angle, wherein the said mechanism the rotatable link forms a turning pair with the fixed frame link while another turning pair is between the fixed frame link and the link that positions the micrometer head at the required angle, linearly variable link adapted to operate on a screw pair and is connected to the rotatable link via micrometer end connector with a self-aligning bearing, the linear motion imparted to the micrometer head adapted to be transferred to the rotating link through self-aligning bearing connected to the micrometer head by means of an end connector such that the mechanism produces precision angular motion through turning pair-screw pair and self-aligning bearing combination. The system is adapted for advantageous precision angular motion involving an angular motion stage, in which micrometer spindle end is operatively linked to a double row self aligning ball bearing with selective connector and clamp holding the micrometer head is mounted on a radial bearing to facilitate adjusting the angular orientation of micrometer when the spindle feed is given to produce angles. 6 Importantly, the above system is directed to combine precision and constrained angular motion about single axis of rotation at any orientation using linear drives. The system is further adapted for fine resolution, good range and repeatability by way of an user friendly less weight, small sizes and cost-effective means for the said precision and constrained angular motion. In accordance with an aspect of the present invention there is provided a system for precision angular motion mechanism for alignment and positioning of optical elements /other like applications having an open -ended micrometer clamp based mechanism comprising: a fixed link adapted as frame-; a link holding the micrometer head, comprising micrometer clamp-, linearly variable link comprising the micrometer spindle means-; a rotatable link -that positions the optics at required angle and also designed to adapt coarse positioning top. The constraining between the above links is as given below: Micrometer clamp is guided at one end preferably at its bottom by fixed link (turning pair using bearings) Micrometer spindle operates with a screw pair of the micrometer head, where the said micrometer head is clamped in Self-aligning bearing adapted as an operative joint there between said micrometer spindle and rotatable link through said micrometer end connector; Said rotatable link is properly constrained with frame with proper bearings above said links are selectively paired and adapted selectively for turning pair, screw pair and bearing means for desired precision motion. Preferably, the above system for precision angular motion having an open -ended micrometer clamp based mechanism includes : said micrometer clamp means comprising a split type clamping to securely hold the micrometer head and the said micrometer clamp is supported with respect to said frame link through bearing means at one end (other end as open-ended); 7 said micrometer end connector operatively connected to said bearing means preferably selected from self-aligning to a bracket member preferably L-bracket which is joined to the said rotatable link; said rotating link supported with respect to said frame link through bearing means. In accordance with another aspect of the present invention there is provided a system for precision angular motion mechanism for alignment and positioning of optical elements /other like applications having a hinged type angular stage based mechanism comprising: a fixed frame assembly-; a link for positioning the micrometer head at required angle comprising micrometer clamp that is guided at both top and bottom ; linearly variable link comprising the micrometer spindle means; bearings adapted as an operative joint there between said micrometer spindle and rotatable link through said micrometer end connector; above said link means selectively paired and adapted selectively for turning pair, screw pair and bearing means for desired precision motion. Preferably, the above system for precision angular motion having a hinged type angular stage based mechanism includes: said micrometer clamp means comprising a split type clamping to securely hold the micrometer head and the said micrometer clamp is supported with respect to said frame link through bearing means at top and at the bottom (like a hinge); said micrometer end connector operatively connected to said bearing means preferably selected from self-aligning to a bracket member preferably L-bracket which is joined to the said rotatable link; said rotating link supported with respect to said frame link through bearing means. 8 In the above system for precision angular motion mechanism the said fixed frame assembly can comprises a base block member, a T-holder means secured at one end to said base block member and at its other end to a fixture plate means, said fixture plate means further connected to bottom and top bearing block guides; and said clamp means can comprising the split type clamp holding the micrometer head there between and guided at the bottom by said bottom bearing block guide and at the top by a top bearing block guide. The operative connection there between the fixed frame link and the rotatable link is adapted to be properly constrained by selective bearing means. The said assembly of said micrometer head in said clamp means and its operative connection to the rotatable link through self aligning bearings and said bracket means preferably L-bracket is free of any linear movement other than the intended micrometer head motion. The micrometer end connector is adapted for non-slip connection to the micrometer head and the self-aligning bearings preferably as a force-fit connection. Importantly, the diameter of the end connector is selectively provided to impart pre-load to the self-aligning bearings whereby the radial clearance of the bearing is reduced for improved sensitivity (response) of the angular positioning stage. In accordance with another aspect of the present invention there is provided a system for precision angular motion mechanism for alignment and positioning of optical elements/other applications and also comprising a translation stage for linear motion comprising micrometer head operatively connected to properly constrained and guided movable plate, preferably involving means selected from ball guides, roller guides, linear guides or bearings or assembly pre loading of machined guides, of the stage with the above said end connector and radial bearings as a joint means. According to a further aspect the said angular stage is selectively provided with one or more of (a) tapping/holes in the fixed frame assembly such that angular stage or combination stage can be mounted on another stage or on any other structure for 9 21 MAR 2001 various optical set-ups (b) Properly constrained rotatable and fixed link arrangement with bearings adapted to reduce coupled angular motions. Also the system of the invention is adapted such as to facilitate the mounting of linear motion stage on the angular motion stage or vice versa Importantly, in the above system for precision angular motion mechanism for alignment and positioning of optical elements/other applications the linkage mechanism is adapted to support reflection optics such as monochromators and transmission optics and also transmission through the axis of angular stages. In accordance with a preferred aspect in the system for precision angular motion mechanism for alignment and positioning of optical elements/other applications said angular stage comprise a range of 0 to 22° involving 25 mm travel micrometer head and a range of 0 to 47° involving use of 50 mm travel micrometer head and further adapted for increase in range by (a) reducing overlapping length of end connector and/or (b) reducing the distance between the pivot of rotating link to self-aligning bearing; angular stage has a resolution of 0.01° involving 10 micron resolution micrometer head and 0.001° involving 1 micron resolution micrometer head and further adapted for increase in resolution by (a) involving differntial screw micrometer head and preloading the self-aligning bearing with any or combination of pre loading methods preferably reducing the radial clearance, spring pre-loading and /or (b) increasing the distance between pivot of rotating link to self -aligning bearing and gaining better resolution for the same resolution micrometer head and use of pre-loading as said above. Also according to a further aspect the system for precision angular motion mechanism for alignment and positioning of optical elements/other applications can comprise a through hole is provided in the axis of rotation of the rotary link to thereby provide a clear path for X-rays/light. Advantageously, it is possible to provide the system for precision angular motion mechanism for alignment and positioning of optical elements/other applications 10 comprising mechanized feed control of the micrometer head preferably comprising a stepper motor supported with respect to the fixed frame link. According to yet another aspect of the present invention there is provided a translation stage for precision linear motion for linear positioning and alignment of optical elements comprising: a mounting block; a micrometer clamp tightened to the said mounting block and adapted to clamp the micrometer head; a movable slide supported on the said mounting block and guided by guide blocks to facilitate its sliding movement and further adapted for linear positioning and alignment of optical elements; a bearing block tightly fastened to the movable slide, a micrometer end connector providing a non slip operative connection there between the spindle of micrometer head and a rotary bearing of the bearing block; said desired precise linear motion of the optics for monochromator mounted on the translation stage obtained by the motion of the said micrometer spindle, where the said motion is transferred through tightly secured end connector to the rotary bearing of the bearing block to facilitate sliding motion of the movable slide fastened to the bearing block which is adapted to slide linearly, restrained and guided by said guide blocks. Such a translation stage for linear motion as above can be provided in combination with a system for precision angular motion mechanism for alignment and positioning of optical elements. It is thus possible by way of the above-disclosed system of the invention to achieve precision and constrained angular motion about single axis rotation at any orientation using linear drives. Also the system for precision angular motion of the invention can be adapted to carry further translation drive to precisely position the optical elements using independent linear and angular motions. 11 21 MAR 2007 BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS: The details of the invention its objects and advantages are explained hereunder in greater details in relation to non-limiting examplenary illustrations of the system as per the accompanying figures wherein: Fig 1: is an isometric view of the system for precision angular motion mechanism for alignment and positioning of optical elements involving an open-ended micrometer clamp type mechanism; Fig 1A: is an exploded view of the precision angular motion mechanism of Fig l; Fig1B: is an assembly representation of the precision angular motion mechanism of Figl; Fig 1C: is a sectional illustration of the fixed frame mounting block used in the precision angular motion mechanism of Fig 1; Fig ID: is illustration of the rotating shaft used in precision angular motion mechanism of Fig 1; Fig IE: is a illustration of the micrometer clamp (split type) used in precision angular motion mechanism of Fig 1; Fig IF: is a sectional illustration of the assembly of frame and rotating shaft used in precision angular motion mechanism of Fig 1; Fig 1G: is a illustration of the micrometer end connector used in precision angular motion mechanism of Fig 1; Fig IH: is a illustration of "L" Bracket used in precision angular motion mechanism of Figl; Fig II: is a illustration of the coarse positioning top used in precision angular motion mechanism of Fig 1; 12 Fig 2A: is a schematic representation of turning pair-screw pair and self aligning bearings adapted to produce constrained angular motion in the system of the invention; Fig 2B: is a illustration showing the relation between the mechanism and the geometric of functional purpose of the system of the invention; Fig 2C: illustrated geometric relationship between fixed and rotatable link in a linkage mechanism involving a linear drive as per the system of the invention; Fig 3: is a isometric view of precision angular motion mechanism of the invention involving hinged type angular stage: Fig 3A: is an exploded view of precision angular motion mechanism of Fig 3; Fig 3B: is an assembly drawing illustrating the system for precision angular motion mechanism of Fig 3; Fig 3C: is a illustration of the fixed frame (mounting block) used in precision angular motion mechanism of Fig 3; Fig 3D: is a illustration of the rotary shaft used in precision angular motion mechanism of Fig 2; Fig 3E: is a illustration of the micrometer clamp (split type) used in precision angular motion mechanism of Fig 3; Fig 3F: is a illustration of the "L" bracket used in precision angular motion mechanism of Fig 3; Fig 3G: is a illustration of micrometer end-connector used in precision angular motion mechanism of Fig 3; 13 Fig 3H: is a illustration of T" holder (part of frame) used in precision angular motion mechanism of Fig 3; Fig 31: is a illustration of the fixture plate adapted to hold the bearing block used in the precision angular motion mechanism of Fig 3 Fig 3J: is a illustration of the bearing block used in the precision angular motion mechanism of Fig 3; Fig 3K: is a illustration of the coarse positioning top used in the precision angular motion mechanism of Fig 3; Fig 4: is an isometric view illustrating the translation stage adapted to carry/support optics for monochromator or any other mounts adapted for use in relation to the above system of the invention; Fig 4A: is an exploded view of the translation stage of Fig 4; Fig 4B: is an assembly drawing of the translation stage of Fig 4; Fig 4C: is a illustration of the mounting block (fixed plate) used in the translation stage of Fig 4; Fig 4D: is a view of the movable slide used in the translation stage of Fig 4; Fig 4E: is a illustration of the guide blocks used in the translation stage of Fig 4; Fig 4F: is a sectional illustration of the bearing block used in the translation stage of Fig 4; Fig 4G: is an illustration of the micrometer clamp (fixed type) used in the translation stage of Fig 4; Fig 4H: is a representation of the assembly of micrometer head end connector and bearing block used in the translation stage of Fig 4; 14 Fig 41: is a illustration of micrometer end connector used in the translation stage of Fig 4; Reference is first invited to accompanying figure 1 which provides schematic illustration of embodiment of the system for precision angular motion mechanism for alignment and positioning of optical elements involving a turning pair-screw pair and self aligning ball bearing wherein the system provides an open-ended micrometer clamp type mechanism. As illustrated in said figure the system basically involves linkage mechanism consisting of turning pair-screw pair and self-aligning bearing to achieve the precision angular motion required for alignment and positioning of optical elements. In particular, the pair between the fixed frame link (LI) and another link denoted as micrometer clamp (L2) is a turning pair, while micrometer head (L3) which is clamped in L2 provides the screw pair and the pair there between the micrometer head (L3) and the rotary shaft link (L4) is self aligning ball bearing for effective precision motion (successively the said pairs are between L1-L2; L2-L3 and L3-L4). The mechanism is completed with another properly constrained turning pair between frame (LI) and rotatable link (L4) The fixed frame link (LI) acts as a frame of the angular stage, the rotatable link (L4) carries a coarse positioning top adapted for mounting for optical elements, the link comprising micrometer head clamp (L2) holds the micrometer head while the micrometer head constitutes the further link (L3). Preferably the micrometer is selected to have a resolution of 10 Microns or better. Importantly the fixed frame link (LI) and the rotary link (L4) are adapted to have no limitation to hold either reflection optics such as monochromators or transmission optics. Transmission through the axis of the stage can also be achieved by provision of hollow path through the stages preferably involving selective bearings for such purpose. Since the link 1 is provided as a frame structure, it can be provided either in a single piece or in more than one pieces and screwed and joint together. The links comprising the frame (LI) and the rotary link (L4) is properly constrained preferably by use of bearings. For the purpose bearings can be selected from variety 15 21 MAR 2001 of options with the primary object of constraining to avoid any coupled orientation. Preloaded bearings, assembly preloading or established precision assemble methods in optical stages are followed. Likewise the fixed frame link (LI) and the clamping link (L2) are also required to be properly constrained to achieve the desired precision angular motion, the micrometer head (L3) and the rotary link (L4) are assembled through self-aligning bearing. The assembling of micrometer head (L3), the clamping link (L2) and the rotary link (L4) are assembled such as not to give any linear movement (slip in assemble, creeping) other than provided by micrometer head. The self-aligning bearing is thus adapted to be prevented from sliding or linear movement. The micrometer should also be prevented from sliding at the assembling with the micrometer clamp (L2). The manner of assembling of the system to achieve the above is explained in greater detail in relation to accompanying figures 1A to 1H illustrate the operative components connecting the linkage mechanism used in the system comprising the fixed frame link (LI), rotatable link (L4), link (L2) to position the micrometer clamp or the link (L3) comprising the micrometer spindle. Reference is invited to accompanying fig 1A, which illustrates by way of an exploded view the operative connection and components details of the open-ended micrometer clamp type system of the embodiment of figure 1. As shown in said figure the link (LI) is obtained of the frame (1), the rotary link (L2) comprising of rotary shaft (2) and bearings (8 & 9) used between said frame (1) and the rotating link (2), a micrometer clamp/split type constituting the link (L2) while the micrometer head constitutes link (L3). As further apparent of said figure in order to achieve the desired constraining of the link between the micrometer head (6) and the rotary shaft (2), the micrometer head (6) is operatively connected to the WL" bracket (5) through the micrometer end connector (4) and the self aligning bearing (11) and the snap ring (12). Also for proper constraining and non-slip positioning of the micrometer head the micrometer clamp (3), and bearings (10) are used there between the frame and the micrometer clamp. 16 The above discussed assembling of components to achieve the desired constrained precision angular motion would be further apparent by way of the illustrated component configuration further detailed by way of accompanying figures 1C to 1H. Reference is invited to accompanying Figure IF, which illustrates the assembly of fixed and rotatable links Reference is invited to Figure 1G, which illustrates the micrometer end connector used in the system of the invention. The said micrometer end connector is adapted such that it connects micrometer head and self-aligning bearing. Preferably, it is connected to the micrometer head with force fit and similarly it is connected to the inside diameter of self-aligning bearing with a force fit. Importantly, there should be no slip between micrometer head and the connector. Similarly there should be no slip between inside diameter of self-aligning bearing and connector. Alternatively, it is also possible that the connector be joined to the micrometer using any temporary or permanent joining methods such as welding, adhesives etc. Similarly it may be joined to bearing using adhesives or any other standard practice provided the required purpose is served. The end connector functions such that it transmits micrometer motion to the bearing without any slip. The diameter of the connector is selected to give a calculated pre load to the self-aligning bearing (a slight interference) by which the radial clearance of the bearing is reduced. This improves the performance (sensitivity) of the angular positioning stage. It is also possible that the micrometer head is directly connected to the bearing in the absence of end connector. But in such case the system does not include the favorable features of the end connector discussed above. Also any standard size of the suitably selected bearing and a standard micrometer head can be used if the end connector is used (because if the end connector is used it is not necessary that basic dimension of inside diameter of the bearing and out side diameter of the micrometer head are equal). This is not possible if the micrometer is directly connected to the bearing. The role of end connector in linear motion stage is also similar to its function in angular stage i.e. to transmit the micrometer feed to the inner race of bearing without slip. However in case of linear motion stage deep groove ball bearing can be used in place of self-aligning bearing. 17 The critical dimensions of the end connector depends on the inside diameter of the bearing and out side diameter of the micrometer head. However there is no restriction to use only a small sized bearing in comparison to out side diameter of the micrometer head. The bearing can be selected by considering other factors such as size of the stage, load-carrying capacity etc. Importantly, the above system achieves precision angular motion by way of a) selective properly constrained assembling of link (LI) and link (L4) whereby it is possible to achieve the required accuracy of angular motion about the rotating axis. Any improper assembling or excessive radial play causing coupled angular motion is effectively taken care of, b) the self aligning bearing is prevented from sliding or linear motion in its housing and also between end connector and inner race of bearing. The sliding between the micrometer clamp and the micrometer head is also prevented, c) the linkage mechanism as above is further adapted to support the reflection optics such as monochromators and also transmission through the axis of angular stage. Reference is now invited to accompanying figures 2A to 2C which illustrate in greater detail the manner of achieving the turning pair, screw pair and self aligning bearing to produce the constrain angular motion. As apparent from figure 2A the mechanism of operation of the system for precision angular motion of the invention involving the operative linking mechanism of the fixed frame link (LI), the micrometer clamp link (L2), micrometer spindle link (L3) and rotary link (L4) are all illustrated in said figure. Importantly the manner of providing for the turning pair is represented by PI and P2 while the screw pair is represented by P3 and the self aligning bearing provision by P4. Further the relation between geometry and the mechanism of action to achieve the precision angular motion using the above link mechanism is further shown in figure 2B. as illustrated in said figure 2B, in the above system, the link (L2) for positioning the micrometer clamp is perpendicular to the plane of paper. The orientation (angular) of micrometer head (L3) is changed with respect to both the fixed and rotatable links. It would be apparent from the representative triangle in the figures that 18 21MAR 2007 length of the other two sides remain unaltered. The side BC in the representative triangle correspond to the micrometer spindle while Reference is further invited to figure 2C, which illustrate the geometrical relation between fixed and rotatable link in the linkage mechanism using a linear drive. Whenever a feed is given to micrometer head to produce angle, the orientation of this linear drive in different position 1, 2,3, 4 & 5 varies with respect to both the fixed link and also the rotatable link. The distance between point F and the intersection of circle in the said positions 1,2,3,4 & 5 represents length of micrometer spindle link Reference is now invited to accompanying figure 3A to 3K, which illustrate another embodiment of the system for precision angular motion mechanism for alignment and positioning of optical elements of the invention involving hinged type angular stage. As clearly illustrated in figure 3, the system according to this embodiment basically involves the operative linkage mechanism involving the fixed frame link (LI), the rotary link (L4), the micrometer clamp link (L2) and the micrometer spindle (L3) to achieve the desired angular precision motion. Importantly however in this embodiment involving the hinged type angular stage, the micrometer clamp link (L2) is guided at both ends i.e. the top and bottom end by provision of selective guides to effectively constrain the micrometer clamp link. For this purpose the clamp link is supported with the bearings in bearing blocks that provide the desired constrained guiding of the clamp link. The fixed frame link (1) in this embodiment is basically comprised of a mounting block, a T" holder which is joined to the mounting block at one end and to a fixture plate at other end, which in turn connected to the bearing blocks to provide for a fixed frame assembling. However fixure plate and "T" holder and bottom bearing block can also be made from a single piece. The operative components activating the above link mechanism for the constrained angular motion is explained in greater detail hereunder in relation to figures 3A to 3K. 19 As shown by way of the exploded view of the system of figure 3 in the accompanying figure 3A, in such an embodiment the system basically involves the frame/mounting block (1) which is joined to the bearing guides of the micrometer clamp link (3) through the T" holder (6) and the fixture plate (7). Once assembled the mounting block (1), the WT" holder (6), fixture plate (7) and the bearing blocks (8) provide a fixed frame structure (LI). The rotary shaft (2) is supported with respect to the mounting block (1) through selective bearing arrangement and carries at the top, the coarse positioning top (9). The link comprising micrometer head (L3) is operatively connected to said rotary shaft link (L4) . the micrometer head (12) is clamped with micrometer clamps (3) with said micrometer head operatively connected to said rotary shaft via micrometer end connector (5), self aligning bearings (13) and the "L" bracket (4). Once assembled the above operative linkage mechanism provides the desired constrained angular motion for alignment and positioning of optical elements involving turning pair, screw pair and self aligning bearing. The component configuration involved in the above system is illustrated by way of the component specification as per figures 3B to 3K. [n accordance with another aspect of invention, there is provided a translation stage adapted to carry the holder on a movable slide to hold optics for monochromator. Alternatively the stage can also carry a plate having a step in the height to thereby provide for a wide flat platform covering length equal to the mounting block for supporting any other mounts/optics. Reference is invited to accompanying figure 4, which provides for a schematic illustration of the translation stage in accordance with present invention. As shown in said figure and also in the accompanying figure 4A (exploded view) the translation stage is provided to comprise of the mounting block (1) which is provided to securely hold the micrometer clamp (5) with the micrometer head (6) effectively clamped with respect to said micrometer clamp (5). A micrometer end connector (7) is shown operatively connected at one end to the micrometer head and at its other end to the bearing block (4). movable slide (2) is joined with the bearing block and guided by guides (3). This movable slide is adapted to move and carry the holder holding the optics for the monochromator. The exploded view further illustrates the operative connection of the components 20 constituting the translation stage system of the invention including the provision of preloading screws (8) and the locking screws (9) of the guides. The design of movable slide and the use of micrometer end connector-bearing joint made the size of translation stage very small. The size of this stage is 54mm (length-excluding micrometer) x 35mm (width) x 29.6mm (height- including projected height) and this stage produces a travel of 22mm. The material of construction can be stainless steel for different links, but use of other ferrous materials and also non-ferrous materials like Aluminum alloys are also suitable. Nylon can be used for very lightweight stages. The weight of the combination stage (including angular and translation stage as per the disclosed size, higher bearing size with a base size 45mmSq.) is about l000gms when the material is steel. But when the components of the angular stage are made using Aluminum the weight of the stage was 600gms. The weight can be further reduced using nylon for construction of angular stage in suitable cases. The resolution of the angular stage with the given dimensions is ~ 0.01° when the micrometer head used is having a resolution of 10 microns. The resolution is improved to ~ 0.001° when 1 micron resolution micrometer head is used for hinged type stage. Range of the instrument is 0 to 22° when 25mm micrometer head is used with the given dimensions of angular stage. If 50mm micrometer head is used the range become 0 to 47°. Initially some (up to 3mm) motion of micrometer will be reduced due to the fitting of end connector. Range of linear motion stage is 0 to 22mm and resolution of linear motion stage is 10-micron when using a micrometer of 10-micron resolution and 25mm travel It is thus possible by way of the above-disclosed system of the invention to eliminate spring in angular and linear motion stages using bearing joint and increasing the performance using end connector. In particular for said angular motion stage, the turning pair-screw pair and self-aligning bearing combination act as a joint between the rotating link (L4) and the micrometer head (13). Whenever the feed is given by the micrometer head the motion is transferred to the rotating link (L4) through the self aligning bearing. However, as the direction is reversed some error comes into play, which depends on bearing clearance and also on micrometer accuracy. Similarly, sensitivity- response, resolution of stage is also 21 affected by bearing clearances. Thus in both the cases dimensions of end connector play an important role to introduce suitable interference with the inner race of bearing and reducing the radial clearance. As regards linear motion stage here also bearings act as a joint between the moving and fixed plates and the radial clearances are affected by the end connection dimensions. Importantly, comparative tests carried out of the system for precision angular motion of the invention with respect to a goniometer has confirmed the fine resolution, good range and repeatability achieved by the system of the invention. The turning -pair, screw pair and self -aligning bearing combination of the system is found to achieve required resolution of 0.001° and respond to minute linear feed of 1 micron and transfer the motion to the operative rotating link. The repeatability of the system was found to be better than 9 arc seconds. Translation stages made using micrometer end connector and deep groove ball bearing as a joint can also be used for resolution better than 10 microns. It is thus possible by way of the above disclosed system for precision angular motion to achieve precision and constrained angular motion about single axis of rotation at any orientation using linear drives along with translation drive to preciously position the optical element involving independent linear and angular motions. The system combines selectively fine resolution, good range and repeatability, self-locking, less weight, small size and cost effective. 22 WE CLAIM: 1. A system for precision angular motion mechanism for alignment and positioning of optical elements comprising: a linkage mechanism adapted for constrained angular motion comprising (a) fixed frame link (b) rotatable link (c) linearly variable link and (d) link to position the micrometer head at required angle, wherein the said mechanism the rotatable link forms a turning pair with the fixed frame link while another turning pair is between the fixed frame link and the link that positions the micrometer head at the required angle, linearly variable link adapted to operate on a screw pair and is connected to the rotatable link via micrometer end connector with a self-aligning bearing, the linear motion imparted to the micrometer head adapted to be transferred to the rotating link through self-aligning bearing connected to the micrometer head by means of an end connector such that the mechanism produces precision angular motion through turning pair-screw pair and self-aligning bearing combination. 2. A system for precision angular motion mechanism for alignment and positioning of optical elements having an open-ended micrometer clamp based mechanism comprising: a fixed frame link; a rotatable link that positions the optics at required angle and also adapted to support a coarse positioning top; said frame link and said rotatable link properly constrained; a link for positioning the micrometer head at required angle comprising micrometer clamp guided at one end preferably at its bottom by said fixed link; linearly variably link comprising the micrometer spindle means; bearing adapted as an operative joint there between said micrometer spindle and rotatable link through said micrometer end connector; 23 above said link means selectively paired and adapted selectively for turning pair, screw pair and bearing means for desired precision motion. 3. A system for precision angular motion mechanism as claimed in claim 2 comprising: said micrometer clamp means comprising a split type clamping means to securely hold the micrometer head ; said micrometer end connector in turn operatively connected to said bearing means preferably selected from self-aligning to a bracket member preferably L-bracket which is joined to the said rotatable link; said rotating link supported with respect to said frame link through bearing means preferably selected from pre-loaded or assembly pre-loaded bearings. 4. A system for precision angular motion mechanism for alignment and positioning of optical elements having a hinged type angular stage based mechanism comprising: a fixed frame assembly; a rotatable link that positions the optics at required angle and also adapted to support a coarse positioning top; said frame assembly and said rotatable link properly constrained; clamp link means for positioning the micrometer head at required angle comprising micrometer clamp that is guided at both top and bottom; bearings adapted as an operative joint there between said micrometer head and rotatable link through said micrometer end connector; linearly variable link comprising the micrometer spindle means; above said link means selectively paired and adapted selectively for turning pair, screw pair and bearing means for desired precision motion. 24 5. A system for precision angular motion mechanism as claimed in claim 4 comprising: said micrometer clamp means comprising a split type clamping means to securely hold the micrometer head; said micrometer end connector in turn operatively connected to said bearing means preferably selected from self-aligning bearing to a bracket member preferably L-bracket which is joined to the said rotatable link; said rotating link supported with respect to said frame link through bearing means preferably selected from pre-loaded or assembly pre-loaded bearings. 6. A system for precision angular motion mechanism as claimed in anyone of claims 4 or 5 wherein said fixed frame assembly comprises a base block member, a T-holder means secured at one end to said base block member and at its other end to a fixture plate means ,said fixture plate means further connected to a bottom bearing block guides; said clamp means comprising the split type clamp supporting the micrometer head there between and guided at the bottom by said bottom bearing block guide and at the top by a top bearing block guide. 7. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 6 wherein said operative connection there between the fixed frame link and the rotatable link is adapted to be properly constrained by selective bearing means. 8. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 7 wherein said assembly of said micrometer head in said clamp means and its operative connection to the rotatable link through self aligning bearings and said bracket means preferably L-bracket is adapted to be free of any linear movement other than the intended micrometer head motion. 25 9. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 8 wherein the linkage mechanism is adapted to support reflection or transmission optical elements and also for through axis transmission in angular stages. 10. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 9 wherein the micrometer end connector is adapted for non-slip connection to the micrometer head and the self-aligning bearings preferably as a force-fit connection. 11. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 10 wherein the diameter of the end connector is selectively provided to impart pre-load to the self -aligning bearings whereby the radial clearance of the bearing is reduced for improved sensitivity of the angular positioning stage. 12. A system for precision angular motion mechanism for alignment and positioning of optical elements claimed in anyone of claims 1 to 11 comprising translation stage for linear motion comprising micrometer head operatively connected to properly constrained and guided movable plate, preferably involving means selected from ball guides, roller guides, linear guides or bearings, or assembly pre-loading of machined plates of the stage with the above said end connector and radial bearings as a joint means. 13. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 11 comprising stages selectively provided with one or more of (a) hollow path provided through the stages preferably including selective bearings for such path, (b) tapping/holes in the fixed frame assembly such that angular stage or combination stage can be mounted on another stage or on any other structure for various optical set-ups, (c) constrained rotatable and fixed link arrangement with pre-loading of bearings adapted to reduce coupled angular motions. 14. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 11 comprising mounting of linear motion stage on the angular motion stage or vice versa. 26 15. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 14 wherein said angular stage comprise a range of 0 to 22° involving 25 mm travel micrometer head and a range of 0 to 47° involving use of 50 mm travel micrometer head and further adapted for increase in range by (a) reducing overlapping length of end connector and/or (b) reducing the distance between the pivot of rotating link to self-aligning bearing; angular stage has a resolution of 0.01° involving 10 micron resolution micrometer head and 0.001° involving 1 micron resolution micrometer head and further adapted for increase in resolution by (a) involving differential screw micrometer head and pre-loading the self-aligning bearing with any or combination of pre loading methods preferably reducing the radial clearance, spring pre-loading and /or (b) increasing the distance between pivot of rotating link to self-aligning bearing and gaining more resolution for the same resolution micrometer head and use of pre-loading as said above. 16. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 14 wherein a through hole is provided in the axis of rotation of the rotary link to thereby provide a clear path for X-rays/light. 17. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 16 comprising mechanized feed control of the micrometer head preferably comprising a stepper motor supported with respect to the fixed frame link. 18. A translation stage for precision linear motion for linear positioning and alignment of optical elements comprising: a mounting block; a micrometer clamp tightened to the said mounting block and adapted to clamp the micrometer head; a movable slide supported on the said mounting block and guided by guide blocks to facilitate its sliding movement and further adapted for linear positioning and alignment of optical elements; a bearing block tightly fastened to the movable slide, 27 21MAR 2007 a micrometer end connector providing a non slip operative connection there between the spindle of micrometer head and a rotary bearing of the bearing block; said desired precise linear motion of the optics for monochromator mounted on the translation stage obtained by the motion of the said micrometer spindle, where the said motion is transferred through tightly secured end connector to the rotary bearing of the bearing block to facilitate sliding motion of the movable slide fastened to the bearing block which is adapted to slide linearly, restrained and guided by said guide blocks. 19. A translation stage as claimed in claim 18 comprising of light weight components and compact in size for easy handling. 20. A system for precision angular motion mechanism for alignment and positioning of optical elements and a translation stage substantially as herein described and illustrated with reference to the accompanying figures. Dated this 23rd day of July 2005. Anjan Sen Of Anjan Sen & Associates (Applicant's Agent) 28

Full Text

FORM 2
THE PATENT ACT 1970
(39 OF 1970)
&
The Patent Rules, 2003

COMPLETE SPECIFICATION
(See section 10 and rule 13)
1 TITLE OF THE INVENTION : A SYSTEM FOR PRECISION ANGULAR MOTION MECHANISM FOR ALIGNMENT AND POSITIONING OF OPTICAL ELEMENTS

2 APPLICANT (S)
Name
Nationality
Address

: THE SECRETARY, DEPARTMENT OF ATOMIC ENERGY
: An Indian Government Department Govt, of India, Anushakti Bhavan, Chatrapati Shivaji Maharaj Marg,Mumbai 400039, Maharastra, India.

3 PREAMBLE TO THE DESCRIPTION
COMPLETE
The following specification particularly descibes the invention and the manner in
which it is to be performed:

27NOV 2006

FIELD OF THE INVENTION
The present invention relates to a system for producing constrained angular motion and, in particular, to a system for precision angular motion mechanism for alignment and positioning of optical elements using a selective combination of turning pair-screw pair and self aligning ball-bearing. The system is specifically adapted for use in precision angular motion mechanism when the output is monitored (photon detectors or interference patterns) such as monochromators in hard X-ray and positioning devices in various visible optical setups. The system is also adapted for angular positioning of optical elements when it is calibrated, also in miniature and large angular stages with fine resolutions in different mechanical applications. The invention also relates to a small sized translation stage involving micrometer head such that the combination of the angular and translation stages is small sized, having good resolution and range and is less weight and cost effective. The system is compact, user-friendly and also cost-effective for wide scale use /application
BACKGROUND ART
The provision of mechanism for use in angular positioning of optical elements is well known. Conventional devices and mechanisms known for such angular positioning of optical elements include:
Worm and gear driven goniometers, which produce fine resolutions when worm rotates a gear. Gear ratio determines the magnitude of such resolution. Many commercial designs, which work on this principle are also available. (Foundations of mechanical accuracy Moore special tool company, Library of Congress Catalogue No. - 73-127307)
Micrometers used push an extended rod in swivel stages having arc shaped crossed roller guide to produce constraint angular motion is also known. Such system is commercially made available by M/s Kohzu Precision Company Limited Item No. -ST05A-SIT and the complete series.
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Standard sine-bar mechanism and its applications are also known wherein micrometer pushes a sine-bar to produce angle. Tiwari M.K., Gowri Sankar B., Raghuvanshi V.K., Nandedkar R.V. and Sawhney KJ.S. "Development of total reflection X-ray fluorescent spectrometer for ultra trace analysis Bull Mater. Sci. Vol 25 No. 5, October 2002, pp435-441.
It is also known in the art to provide variety of mirror tilt mounts using screws and spring force.
US 3814365 disclose an adjustable mount for rotatably orienting a structure such as an optical element, about two orthogonal axes comprising first and second orthogonal cross-spring pivots and respectively associated first and second coarse fine adjustment mechanism. Each cross spring pivots includes a first member and a second member which is rotatable relative to the first member, these two members being connected by first and second interleaved flat leaf springs which intersects along the respective axes of rotation. Application of a torque of a second member, which has the optical element, mounted thereon, causes rotation thereof relative to the first member about the axis of rotation. Utilizing at least five interleaved spring portions provide substantially improved mechanical stability.
US 5019837 discloses a mirror mounting structure with low thermal drift which is enabled by providing a mirror mounting structure which vertically and/or horizontally aligns the mirror by providing two point forces against the mirror holding structure. The mirror holding arm is connected to a thick more rigid arm by resilient narrow slightly flexible neck portion. Screws threaded through the large arm contact alignment points on the mirror mount portion and permit accurate alignment in a desired plane. Thermal drift and hysteresis is minimized since the alignment forces are acting upon the mirror mount portion in the same direction and minimize the deviations caused by thermal expansion.
It is also known to achieve angular positioning of optical elements by way of three point adjustments using screws. One of the screws is rotated to get the desired tilt. Likewise four point adjustments are also proposed in the art.
3

While the above state of the art reveal the knowledge prevailing in the art on the provision of variety of devices / mechanisms for angular positioning of optical elements, however, such known mechanisms /devices are found to have some inherent limitation/drawbacks. The drawbacks associated with the known systems include the following:
i) Construction of precise goniometer requires accurate fabrication of worm
and gears. The processes thus require special purpose machines and metrology. Such factors usually tend to increase the cost of the optical positioning device.
ii) The Micrometer push driven stages which is provided with arc shaped cross roller guides have less range of ~±3°.
iii) It is also known to use inexpensive alternative to goniometer by use of precise linear drives (such as Micrometer head) and convert it into angular motion. In the same principle sine-bar mechanism also works. Importantly while the sine-bar mechanism can also be efficiently used for precise motions, but such mechanism involves spring loading or gravity returns and is found to be not stable when mounted on other parts rotating about horizontal axis.
iv) Importantly it is found that various springs used in optical tilt mounts cause problems in stable optics especially when these mounts are mounted on another rotating part of high precision system. Also angular adjustments introduce some linear variation of optical elements along with rotation because optical elements are mounted away from pivot (axis of rotation do not pass through the reflecting surface of optical elements). Similar problems persist in the US 3814365.
v) Angular adjustments using two point forces using screws against resilient neck portion of the structure that allows elastic deformation is a design meant for stable mirror mounting with low thermal drift. This design does not provide continuous variation of angle with good resolution and range using a single input, which is a problem in using them as optical rotational stages.
vi) Also three point and four point adjustable mechanisms usually do not provide completely constrained angular motion about a single axis. Also

4

angular motion is found to cause some linear displacement of optical elements.
OBJECTS OF THE INVENTION
It is thus the basic object of the present invention to provide for a system for precision and constrained angular motion about single axis of rotation at any orientation using linear drives along with possible translation drive to preciously position the optical element involving independent linear and angular motions involving mechanism comprising selectively of turning pair, screw pair and self-aligning bearings without the need for spring returns.
Another object of the present invention is to provide a system for precision and constrained angular motion for alignment and positioning of optical elements comprising selectively features including fine resolution, good range and repeatability, self locking, less weight, small size and cost effective.
Another object of the present invention is to provide a system for precision and constrained angular motion adapted for use as exit arm monochromator stage of hard X-ray diffractometer for settling the required angle of monochromator.
A further object of the present invention is to provide precision angular motion mechanism for alignment and positioning of optical elements which can be carried out using linear drive and would favour stable angular positioning and alignment stages.
Yet further object of the present invention is to provide constrained angular motion stages of different sizes depending upon the end use/application.
Another object of the present invention is directed to provide a system for angular positioning and alignment for optical elements, which would be cost effective for constructing precision stages without the use of worm and gear.
A further object of the present invention is directed to provide for a small sized translation stage involving micrometer head such that the combination of the
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2 1 MAR 2007

angular and translation stages is small sized, provide good resolution and range and is less weight and cost effective.
Another object of the invention is to provide a selective end connector connection there between a micrometer head and ball bearing which would favour direct coupling of the micrometer head to the ball bearing and also provide an end connector based feed in translation stages without need of spring returns as well as construction of open-ended micrometer clamp type rotation stages without need of spring returns.
Yet further object of the present invention is directed to provide a system for constrained angular motion for alignment and positioning of optical elements where by the connector would be adapted to allow constructing of hinged and micrometer feed angular motion stages without use of spring returns.
SUMMARY OF THE INVENTION
Thus according to the basic aspect of the present invention there is provided a system for precision angular motion mechanism for alignment and positioning of optical elements comprising:
a linkage mechanism adapted for constrained angular motion comprising (a) fixed frame link (b) rotatable link (c) linearly variable link and (d) link to position the micrometer head at required angle, wherein the said mechanism the rotatable link forms a turning pair with the fixed frame link while another turning pair is between the fixed frame link and the link that positions the micrometer head at the required angle, linearly variable link adapted to operate on a screw pair and is connected to the rotatable link via micrometer end connector with a self-aligning bearing, the linear motion imparted to the micrometer head adapted to be transferred to the rotating link through self-aligning bearing connected to the micrometer head by means of an end connector such that the mechanism produces precision angular motion through turning pair-screw pair and self-aligning bearing combination.
The system is adapted for advantageous precision angular motion involving an angular motion stage, in which micrometer spindle end is operatively linked to a double row self aligning ball bearing with selective connector and clamp holding the micrometer head is mounted on a radial bearing to facilitate adjusting the angular orientation of micrometer when the spindle feed is given to produce angles.
6

Importantly, the above system is directed to combine precision and constrained angular motion about single axis of rotation at any orientation using linear drives. The system is further adapted for fine resolution, good range and repeatability by way of an user friendly less weight, small sizes and cost-effective means for the said precision and constrained angular motion.
In accordance with an aspect of the present invention there is provided a system for precision angular motion mechanism for alignment and positioning of optical elements /other like applications having an open -ended micrometer clamp based mechanism comprising:
a fixed link adapted as frame-;
a link holding the micrometer head, comprising micrometer clamp-, linearly variable
link comprising the micrometer spindle means-;
a rotatable link -that positions the optics at required angle and also designed to
adapt coarse positioning top.
The constraining between the above links is as given below:
Micrometer clamp is guided at one end preferably at its bottom by fixed link (turning
pair using bearings)
Micrometer spindle operates with a screw pair of the micrometer head, where the
said micrometer head is clamped in Self-aligning bearing adapted as an operative
joint there between said micrometer spindle and rotatable link through said
micrometer end connector;
Said rotatable link is properly constrained with frame with proper bearings
above said links are selectively paired and adapted selectively for turning pair, screw pair and bearing means for desired precision motion.
Preferably, the above system for precision angular motion having an open -ended micrometer clamp based mechanism includes :
said micrometer clamp means comprising a split type clamping to securely hold the micrometer head and the said micrometer clamp is supported with respect to said frame link through bearing means at one end (other end as open-ended);

7

said micrometer end connector operatively connected to said bearing means preferably selected from self-aligning to a bracket member preferably L-bracket which is joined to the said rotatable link;
said rotating link supported with respect to said frame link through bearing means.
In accordance with another aspect of the present invention there is provided a system for precision angular motion mechanism for alignment and positioning of optical elements /other like applications having a hinged type angular stage based mechanism comprising:
a fixed frame assembly-;
a link for positioning the micrometer head at required angle comprising micrometer
clamp that is guided at both top and bottom ;
linearly variable link comprising the micrometer spindle means;
bearings adapted as an operative joint there between said micrometer spindle and
rotatable link through said micrometer end connector;
above said link means selectively paired and adapted selectively for turning pair, screw pair and bearing means for desired precision motion.
Preferably, the above system for precision angular motion having a hinged type angular stage based mechanism includes:
said micrometer clamp means comprising a split type clamping to securely hold the micrometer head and the said micrometer clamp is supported with respect to said frame link through bearing means at top and at the bottom (like a hinge);
said micrometer end connector operatively connected to said bearing means preferably selected from self-aligning to a bracket member preferably L-bracket which is joined to the said rotatable link;
said rotating link supported with respect to said frame link through bearing means.
8

In the above system for precision angular motion mechanism the said fixed frame assembly can comprises a base block member, a T-holder means secured at one end to said base block member and at its other end to a fixture plate means, said fixture plate means further connected to bottom and top bearing block guides; and said clamp means can comprising the split type clamp holding the micrometer head there between and guided at the bottom by said bottom bearing block guide and at the top by a top bearing block guide. The operative connection there between the fixed frame link and the rotatable link is adapted to be properly constrained by selective bearing means.
The said assembly of said micrometer head in said clamp means and its operative connection to the rotatable link through self aligning bearings and said bracket means preferably L-bracket is free of any linear movement other than the intended micrometer head motion.
The micrometer end connector is adapted for non-slip connection to the micrometer head and the self-aligning bearings preferably as a force-fit connection. Importantly, the diameter of the end connector is selectively provided to impart pre-load to the self-aligning bearings whereby the radial clearance of the bearing is reduced for improved sensitivity (response) of the angular positioning stage.
In accordance with another aspect of the present invention there is provided a system for precision angular motion mechanism for alignment and positioning of optical elements/other applications and also comprising a translation stage for linear motion comprising micrometer head operatively connected to properly constrained and guided movable plate, preferably involving means selected from ball guides, roller guides, linear guides or bearings or assembly pre loading of machined guides, of the stage with the above said end connector and radial bearings as a joint means.
According to a further aspect the said angular stage is selectively provided with one or more of (a) tapping/holes in the fixed frame assembly such that angular stage or combination stage can be mounted on another stage or on any other structure for
9 21 MAR 2001

various optical set-ups (b) Properly constrained rotatable and fixed link arrangement with bearings adapted to reduce coupled angular motions.
Also the system of the invention is adapted such as to facilitate the mounting of linear motion stage on the angular motion stage or vice versa Importantly, in the above system for precision angular motion mechanism for alignment and positioning of optical elements/other applications the linkage mechanism is adapted to support reflection optics such as monochromators and transmission optics and also transmission through the axis of angular stages.
In accordance with a preferred aspect in the system for precision angular motion mechanism for alignment and positioning of optical elements/other applications said
angular stage comprise a range of 0 to 22° involving 25 mm travel micrometer head and a range of 0 to 47° involving use of 50 mm travel micrometer head and further adapted for increase in range by (a) reducing overlapping length of end connector and/or (b) reducing the distance between the pivot of rotating link to self-aligning bearing;
angular stage has a resolution of 0.01° involving 10 micron resolution micrometer head and 0.001° involving 1 micron resolution micrometer head and further adapted for increase in resolution by (a) involving differntial screw micrometer head and preloading the self-aligning bearing with any or combination of pre loading methods preferably reducing the radial clearance, spring pre-loading and /or (b) increasing the distance between pivot of rotating link to self -aligning bearing and gaining better resolution for the same resolution micrometer head and use of pre-loading as said above.
Also according to a further aspect the system for precision angular motion mechanism for alignment and positioning of optical elements/other applications can comprise a through hole is provided in the axis of rotation of the rotary link to thereby provide a clear path for X-rays/light.
Advantageously, it is possible to provide the system for precision angular motion mechanism for alignment and positioning of optical elements/other applications
10

comprising mechanized feed control of the micrometer head preferably comprising a stepper motor supported with respect to the fixed frame link.
According to yet another aspect of the present invention there is provided a translation stage for precision linear motion for linear positioning and alignment of optical elements comprising:
a mounting block;
a micrometer clamp tightened to the said mounting block and adapted to
clamp the micrometer head;
a movable slide supported on the said mounting block and guided by guide
blocks to facilitate its sliding movement and further adapted for linear
positioning and alignment of optical elements;
a bearing block tightly fastened to the movable slide,
a micrometer end connector providing a non slip operative connection there
between the spindle of micrometer head and a rotary bearing of the bearing
block;
said desired precise linear motion of the optics for monochromator mounted on the translation stage obtained by the motion of the said micrometer spindle, where the said motion is transferred through tightly secured end connector to the rotary bearing of the bearing block to facilitate sliding motion of the movable slide fastened to the bearing block which is adapted to slide linearly, restrained and guided by said guide blocks.
Such a translation stage for linear motion as above can be provided in combination with a system for precision angular motion mechanism for alignment and positioning of optical elements.
It is thus possible by way of the above-disclosed system of the invention to achieve precision and constrained angular motion about single axis rotation at any orientation using linear drives. Also the system for precision angular motion of the invention can be adapted to carry further translation drive to precisely position the optical elements using independent linear and angular motions.
11
21 MAR 2007

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
The details of the invention its objects and advantages are explained hereunder in greater details in relation to non-limiting examplenary illustrations of the system as per the accompanying figures wherein:
Fig 1: is an isometric view of the system for precision angular motion mechanism for alignment and positioning of optical elements involving an open-ended micrometer clamp type mechanism;
Fig 1A: is an exploded view of the precision angular motion mechanism of Fig l;
Fig1B: is an assembly representation of the precision angular motion mechanism of Figl;
Fig 1C: is a sectional illustration of the fixed frame mounting block used in the precision angular motion mechanism of Fig 1;
Fig ID: is illustration of the rotating shaft used in precision angular motion mechanism of Fig 1;
Fig IE: is a illustration of the micrometer clamp (split type) used in precision angular motion mechanism of Fig 1;
Fig IF: is a sectional illustration of the assembly of frame and rotating shaft used in precision angular motion mechanism of Fig 1;
Fig 1G: is a illustration of the micrometer end connector used in precision angular motion mechanism of Fig 1;
Fig IH: is a illustration of "L" Bracket used in precision angular motion mechanism of Figl;
Fig II: is a illustration of the coarse positioning top used in precision angular motion mechanism of Fig 1;

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Fig 2A: is a schematic representation of turning pair-screw pair and self aligning bearings adapted to produce constrained angular motion in the system of the invention;
Fig 2B: is a illustration showing the relation between the mechanism and the geometric of functional purpose of the system of the invention;
Fig 2C: illustrated geometric relationship between fixed and rotatable link in a linkage mechanism involving a linear drive as per the system of the invention;
Fig 3: is a isometric view of precision angular motion mechanism of the invention involving hinged type angular stage:
Fig 3A: is an exploded view of precision angular motion mechanism of Fig 3;
Fig 3B: is an assembly drawing illustrating the system for precision angular motion mechanism of Fig 3;
Fig 3C: is a illustration of the fixed frame (mounting block) used in precision angular motion mechanism of Fig 3;
Fig 3D: is a illustration of the rotary shaft used in precision angular motion mechanism of Fig 2;
Fig 3E: is a illustration of the micrometer clamp (split type) used in precision angular motion mechanism of Fig 3;
Fig 3F: is a illustration of the "L" bracket used in precision angular motion mechanism of Fig 3;
Fig 3G: is a illustration of micrometer end-connector used in precision angular motion mechanism of Fig 3;

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Fig 3H: is a illustration of T" holder (part of frame) used in precision angular motion mechanism of Fig 3;
Fig 31: is a illustration of the fixture plate adapted to hold the bearing block used in the precision angular motion mechanism of Fig 3
Fig 3J: is a illustration of the bearing block used in the precision angular motion mechanism of Fig 3;
Fig 3K: is a illustration of the coarse positioning top used in the precision angular motion mechanism of Fig 3;
Fig 4: is an isometric view illustrating the translation stage adapted to carry/support optics for monochromator or any other mounts adapted for use in relation to the above system of the invention;
Fig 4A: is an exploded view of the translation stage of Fig 4;
Fig 4B: is an assembly drawing of the translation stage of Fig 4;
Fig 4C: is a illustration of the mounting block (fixed plate) used in the translation stage of Fig 4;
Fig 4D: is a view of the movable slide used in the translation stage of Fig 4;
Fig 4E: is a illustration of the guide blocks used in the translation stage of Fig 4;
Fig 4F: is a sectional illustration of the bearing block used in the translation stage of Fig 4;
Fig 4G: is an illustration of the micrometer clamp (fixed type) used in the translation stage of Fig 4;
Fig 4H: is a representation of the assembly of micrometer head end connector and bearing block used in the translation stage of Fig 4;

14

Fig 41: is a illustration of micrometer end connector used in the translation stage of Fig 4;
Reference is first invited to accompanying figure 1 which provides schematic illustration of embodiment of the system for precision angular motion mechanism for alignment and positioning of optical elements involving a turning pair-screw pair and self aligning ball bearing wherein the system provides an open-ended micrometer clamp type mechanism.
As illustrated in said figure the system basically involves linkage mechanism consisting of turning pair-screw pair and self-aligning bearing to achieve the precision angular motion required for alignment and positioning of optical elements. In particular, the pair between the fixed frame link (LI) and another link denoted as micrometer clamp (L2) is a turning pair, while micrometer head (L3) which is clamped in L2 provides the screw pair and the pair there between the micrometer head (L3) and the rotary shaft link (L4) is self aligning ball bearing for effective precision motion (successively the said pairs are between L1-L2; L2-L3 and L3-L4). The mechanism is completed with another properly constrained turning pair between frame (LI) and rotatable link (L4)
The fixed frame link (LI) acts as a frame of the angular stage, the rotatable link (L4) carries a coarse positioning top adapted for mounting for optical elements, the link comprising micrometer head clamp (L2) holds the micrometer head while the micrometer head constitutes the further link (L3). Preferably the micrometer is selected to have a resolution of 10 Microns or better.
Importantly the fixed frame link (LI) and the rotary link (L4) are adapted to have no limitation to hold either reflection optics such as monochromators or transmission optics. Transmission through the axis of the stage can also be achieved by provision of hollow path through the stages preferably involving selective bearings for such purpose. Since the link 1 is provided as a frame structure, it can be provided either in a single piece or in more than one pieces and screwed and joint together. The links comprising the frame (LI) and the rotary link (L4) is properly constrained preferably by use of bearings. For the purpose bearings can be selected from variety
15
21 MAR 2001

of options with the primary object of constraining to avoid any coupled orientation. Preloaded bearings, assembly preloading or established precision assemble methods in optical stages are followed. Likewise the fixed frame link (LI) and the clamping link (L2) are also required to be properly constrained to achieve the desired precision angular motion, the micrometer head (L3) and the rotary link (L4) are assembled through self-aligning bearing.
The assembling of micrometer head (L3), the clamping link (L2) and the rotary link (L4) are assembled such as not to give any linear movement (slip in assemble, creeping) other than provided by micrometer head. The self-aligning bearing is thus adapted to be prevented from sliding or linear movement. The micrometer should also be prevented from sliding at the assembling with the micrometer clamp (L2).
The manner of assembling of the system to achieve the above is explained in greater detail in relation to accompanying figures 1A to 1H illustrate the operative components connecting the linkage mechanism used in the system comprising the fixed frame link (LI), rotatable link (L4), link (L2) to position the micrometer clamp or the link (L3) comprising the micrometer spindle.
Reference is invited to accompanying fig 1A, which illustrates by way of an exploded view the operative connection and components details of the open-ended micrometer clamp type system of the embodiment of figure 1. As shown in said figure the link (LI) is obtained of the frame (1), the rotary link (L2) comprising of rotary shaft (2) and bearings (8 & 9) used between said frame (1) and the rotating link (2), a micrometer clamp/split type constituting the link (L2) while the micrometer head constitutes link (L3). As further apparent of said figure in order to achieve the desired constraining of the link between the micrometer head (6) and the rotary shaft (2), the micrometer head (6) is operatively connected to the WL" bracket (5) through the micrometer end connector (4) and the self aligning bearing (11) and the snap ring (12). Also for proper constraining and non-slip positioning of the micrometer head the micrometer clamp (3), and bearings (10) are used there between the frame and the micrometer clamp.

16

The above discussed assembling of components to achieve the desired constrained precision angular motion would be further apparent by way of the illustrated component configuration further detailed by way of accompanying figures 1C to 1H.
Reference is invited to accompanying Figure IF, which illustrates the assembly of fixed and rotatable links
Reference is invited to Figure 1G, which illustrates the micrometer end connector used in the system of the invention. The said micrometer end connector is adapted such that it connects micrometer head and self-aligning bearing. Preferably, it is connected to the micrometer head with force fit and similarly it is connected to the inside diameter of self-aligning bearing with a force fit. Importantly, there should be no slip between micrometer head and the connector. Similarly there should be no slip between inside diameter of self-aligning bearing and connector. Alternatively, it is also possible that the connector be joined to the micrometer using any temporary or permanent joining methods such as welding, adhesives etc. Similarly it may be joined to bearing using adhesives or any other standard practice provided the required purpose is served.
The end connector functions such that it transmits micrometer motion to the bearing without any slip. The diameter of the connector is selected to give a calculated pre load to the self-aligning bearing (a slight interference) by which the radial clearance of the bearing is reduced. This improves the performance (sensitivity) of the angular positioning stage.
It is also possible that the micrometer head is directly connected to the bearing in the absence of end connector. But in such case the system does not include the favorable features of the end connector discussed above. Also any standard size of the suitably selected bearing and a standard micrometer head can be used if the end connector is used (because if the end connector is used it is not necessary that basic dimension of inside diameter of the bearing and out side diameter of the micrometer head are equal). This is not possible if the micrometer is directly connected to the bearing. The role of end connector in linear motion stage is also similar to its function in angular stage i.e. to transmit the micrometer feed to the inner race of bearing without slip. However in case of linear motion stage deep groove ball bearing can be used in place of self-aligning bearing.

17

The critical dimensions of the end connector depends on the inside diameter of the bearing and out side diameter of the micrometer head. However there is no restriction to use only a small sized bearing in comparison to out side diameter of the micrometer head. The bearing can be selected by considering other factors such as size of the stage, load-carrying capacity etc.
Importantly, the above system achieves precision angular motion by way of a) selective properly constrained assembling of link (LI) and link (L4) whereby it is possible to achieve the required accuracy of angular motion about the rotating axis. Any improper assembling or excessive radial play causing coupled angular motion is effectively taken care of, b) the self aligning bearing is prevented from sliding or linear motion in its housing and also between end connector and inner race of bearing. The sliding between the micrometer clamp and the micrometer head is also prevented, c) the linkage mechanism as above is further adapted to support the reflection optics such as monochromators and also transmission through the axis of angular stage.
Reference is now invited to accompanying figures 2A to 2C which illustrate in greater detail the manner of achieving the turning pair, screw pair and self aligning bearing to produce the constrain angular motion.
As apparent from figure 2A the mechanism of operation of the system for precision angular motion of the invention involving the operative linking mechanism of the fixed frame link (LI), the micrometer clamp link (L2), micrometer spindle link (L3) and rotary link (L4) are all illustrated in said figure. Importantly the manner of providing for the turning pair is represented by PI and P2 while the screw pair is represented by P3 and the self aligning bearing provision by P4.
Further the relation between geometry and the mechanism of action to achieve the precision angular motion using the above link mechanism is further shown in figure 2B. as illustrated in said figure 2B, in the above system, the link (L2) for positioning the micrometer clamp is perpendicular to the plane of paper. The orientation (angular) of micrometer head (L3) is changed with respect to both the fixed and rotatable links. It would be apparent from the representative triangle in the figures that 18 21MAR 2007

length of the other two sides remain unaltered. The side BC in the representative triangle correspond to the micrometer spindle while Reference is further invited to figure 2C, which illustrate the geometrical relation between fixed and rotatable link in the linkage mechanism using a linear drive. Whenever a feed is given to micrometer head to produce angle, the orientation of this linear drive in different position 1, 2,3, 4 & 5 varies with respect to both the fixed link and also the rotatable link. The distance between point F and the intersection of circle in the said positions 1,2,3,4 & 5 represents length of micrometer spindle link
Reference is now invited to accompanying figure 3A to 3K, which illustrate another embodiment of the system for precision angular motion mechanism for alignment and positioning of optical elements of the invention involving hinged type angular stage.
As clearly illustrated in figure 3, the system according to this embodiment basically involves the operative linkage mechanism involving the fixed frame link (LI), the rotary link (L4), the micrometer clamp link (L2) and the micrometer spindle (L3) to achieve the desired angular precision motion. Importantly however in this embodiment involving the hinged type angular stage, the micrometer clamp link (L2) is guided at both ends i.e. the top and bottom end by provision of selective guides to effectively constrain the micrometer clamp link. For this purpose the clamp link is supported with the bearings in bearing blocks that provide the desired constrained guiding of the clamp link.
The fixed frame link (1) in this embodiment is basically comprised of a mounting block, a T" holder which is joined to the mounting block at one end and to a fixture plate at other end, which in turn connected to the bearing blocks to provide for a fixed frame assembling. However fixure plate and "T" holder and bottom bearing block can also be made from a single piece.
The operative components activating the above link mechanism for the constrained angular motion is explained in greater detail hereunder in relation to figures 3A to 3K.

19

As shown by way of the exploded view of the system of figure 3 in the accompanying figure 3A, in such an embodiment the system basically involves the frame/mounting block (1) which is joined to the bearing guides of the micrometer clamp link (3) through the T" holder (6) and the fixture plate (7). Once assembled the mounting block (1), the WT" holder (6), fixture plate (7) and the bearing blocks (8) provide a fixed frame structure (LI).
The rotary shaft (2) is supported with respect to the mounting block (1) through selective bearing arrangement and carries at the top, the coarse positioning top (9). The link comprising micrometer head (L3) is operatively connected to said rotary shaft link (L4) . the micrometer head (12) is clamped with micrometer clamps (3) with said micrometer head operatively connected to said rotary shaft via micrometer end connector (5), self aligning bearings (13) and the "L" bracket (4). Once assembled the above operative linkage mechanism provides the desired constrained angular motion for alignment and positioning of optical elements involving turning pair, screw pair and self aligning bearing. The component configuration involved in the above system is illustrated by way of the component specification as per figures 3B to 3K.
[n accordance with another aspect of invention, there is provided a translation stage adapted to carry the holder on a movable slide to hold optics for monochromator. Alternatively the stage can also carry a plate having a step in the height to thereby provide for a wide flat platform covering length equal to the mounting block for supporting any other mounts/optics. Reference is invited to accompanying figure 4, which provides for a schematic illustration of the translation stage in accordance with present invention. As shown in said figure and also in the accompanying figure 4A (exploded view) the translation stage is provided to comprise of the mounting block (1) which is provided to securely hold the micrometer clamp (5) with the micrometer head (6) effectively clamped with respect to said micrometer clamp (5). A micrometer end connector (7) is shown operatively connected at one end to the micrometer head and at its other end to the bearing block (4). movable slide (2) is joined with the bearing block and guided by guides (3). This movable slide is adapted to move and carry the holder holding the optics for the monochromator. The exploded view further illustrates the operative connection of the components

20

constituting the translation stage system of the invention including the provision of preloading screws (8) and the locking screws (9) of the guides. The design of movable slide and the use of micrometer end connector-bearing joint made the size of translation stage very small. The size of this stage is 54mm (length-excluding micrometer) x 35mm (width) x 29.6mm (height- including projected height) and this stage produces a travel of 22mm.
The material of construction can be stainless steel for different links, but use of other ferrous materials and also non-ferrous materials like Aluminum alloys are also suitable. Nylon can be used for very lightweight stages. The weight of the combination stage (including angular and translation stage as per the disclosed size, higher bearing size with a base size 45mmSq.) is about l000gms when the material is steel. But when the components of the angular stage are made using Aluminum the weight of the stage was 600gms. The weight can be further reduced using nylon for construction of angular stage in suitable cases.
The resolution of the angular stage with the given dimensions is ~ 0.01° when the micrometer head used is having a resolution of 10 microns. The resolution is improved to ~ 0.001° when 1 micron resolution micrometer head is used for hinged type stage. Range of the instrument is 0 to 22° when 25mm micrometer head is used with the given dimensions of angular stage. If 50mm micrometer head is used the range become 0 to 47°. Initially some (up to 3mm) motion of micrometer will be reduced due to the fitting of end connector. Range of linear motion stage is 0 to 22mm and resolution of linear motion stage is 10-micron when using a micrometer of 10-micron resolution and 25mm travel
It is thus possible by way of the above-disclosed system of the invention to eliminate spring in angular and linear motion stages using bearing joint and increasing the performance using end connector. In particular for said angular motion stage, the turning pair-screw pair and self-aligning bearing combination act as a joint between the rotating link (L4) and the micrometer head (13). Whenever the feed is given by the micrometer head the motion is transferred to the rotating link (L4) through the self aligning bearing. However, as the direction is reversed some error comes into play, which depends on bearing clearance and also on micrometer accuracy. Similarly, sensitivity- response, resolution of stage is also

21

affected by bearing clearances. Thus in both the cases dimensions of end connector play an important role to introduce suitable interference with the inner race of bearing and reducing the radial clearance. As regards linear motion stage here also bearings act as a joint between the moving and fixed plates and the radial clearances are affected by the end connection dimensions.
Importantly, comparative tests carried out of the system for precision angular motion of the invention with respect to a goniometer has confirmed the fine resolution, good range and repeatability achieved by the system of the invention. The turning -pair, screw pair and self -aligning bearing combination of the system is found to achieve required resolution of 0.001° and respond to minute linear feed of 1 micron and transfer the motion to the operative rotating link. The repeatability of the system was found to be better than 9 arc seconds. Translation stages made using micrometer end connector and deep groove ball bearing as a joint can also be used for resolution better than 10 microns.
It is thus possible by way of the above disclosed system for precision angular motion to achieve precision and constrained angular motion about single axis of rotation at any orientation using linear drives along with translation drive to preciously position the optical element involving independent linear and angular motions. The system combines selectively fine resolution, good range and repeatability, self-locking, less weight, small size and cost effective.

22

WE CLAIM:
1. A system for precision angular motion mechanism for alignment and positioning of
optical elements comprising:
a linkage mechanism adapted for constrained angular motion comprising (a) fixed frame link (b) rotatable link (c) linearly variable link and (d) link to position the micrometer head at required angle, wherein the said mechanism the rotatable link forms a turning pair with the fixed frame link while another turning pair is between the fixed frame link and the link that positions the micrometer head at the required angle, linearly variable link adapted to operate on a screw pair and is connected to the rotatable link via micrometer end connector with a self-aligning bearing, the linear motion imparted to the micrometer head adapted to be transferred to the rotating link through self-aligning bearing connected to the micrometer head by means of an end connector such that the mechanism produces precision angular motion through turning pair-screw pair and self-aligning bearing combination.
2. A system for precision angular motion mechanism for alignment and positioning of
optical elements having an open-ended micrometer clamp based mechanism
comprising:
a fixed frame link;
a rotatable link that positions the optics at required angle and also adapted to support a coarse positioning top;
said frame link and said rotatable link properly constrained;
a link for positioning the micrometer head at required angle comprising micrometer clamp guided at one end preferably at its bottom by said fixed link;
linearly variably link comprising the micrometer spindle means;
bearing adapted as an operative joint there between said micrometer spindle and rotatable link through said micrometer end connector;
23

above said link means selectively paired and adapted selectively for turning pair, screw pair and bearing means for desired precision motion.
3. A system for precision angular motion mechanism as claimed in claim 2 comprising:
said micrometer clamp means comprising a split type clamping means to securely hold the micrometer head ;
said micrometer end connector in turn operatively connected to said bearing means preferably selected from self-aligning to a bracket member preferably L-bracket which is joined to the said rotatable link;
said rotating link supported with respect to said frame link through bearing means preferably selected from pre-loaded or assembly pre-loaded bearings.
4. A system for precision angular motion mechanism for alignment and positioning of
optical elements having a hinged type angular stage based mechanism comprising:
a fixed frame assembly;
a rotatable link that positions the optics at required angle and also adapted to support a coarse positioning top;
said frame assembly and said rotatable link properly constrained;
clamp link means for positioning the micrometer head at required angle comprising micrometer clamp that is guided at both top and bottom;
bearings adapted as an operative joint there between said micrometer head and rotatable link through said micrometer end connector;
linearly variable link comprising the micrometer spindle means;
above said link means selectively paired and adapted selectively for turning pair, screw pair and bearing means for desired precision motion.
24

5. A system for precision angular motion mechanism as claimed in claim 4 comprising:
said micrometer clamp means comprising a split type clamping means to securely hold the micrometer head;
said micrometer end connector in turn operatively connected to said bearing means preferably selected from self-aligning bearing to a bracket member preferably L-bracket which is joined to the said rotatable link;
said rotating link supported with respect to said frame link through bearing means preferably selected from pre-loaded or assembly pre-loaded bearings.
6. A system for precision angular motion mechanism as claimed in anyone of claims 4
or 5 wherein
said fixed frame assembly comprises a base block member, a T-holder means secured at one end to said base block member and at its other end to a fixture plate means ,said fixture plate means further connected to a bottom bearing block guides;
said clamp means comprising the split type clamp supporting the micrometer head there between and guided at the bottom by said bottom bearing block guide and at the top by a top bearing block guide.
7. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 6 wherein said operative connection there between the fixed frame link and the rotatable link is adapted to be properly constrained by selective bearing means.
8. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 7 wherein said assembly of said micrometer head in said clamp means and its operative connection to the rotatable link through self aligning bearings and said bracket means preferably L-bracket is adapted to be free of any linear movement other than the intended micrometer head motion.
25

9. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 8 wherein the linkage mechanism is adapted to support reflection or transmission optical elements and also for through axis transmission in angular stages.
10. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 9 wherein the micrometer end connector is adapted for non-slip connection to the micrometer head and the self-aligning bearings preferably as a force-fit connection.
11. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 10 wherein the diameter of the end connector is selectively provided to impart pre-load to the self -aligning bearings whereby the radial clearance of the bearing is reduced for improved sensitivity of the angular positioning stage.
12. A system for precision angular motion mechanism for alignment and positioning of optical elements claimed in anyone of claims 1 to 11 comprising translation stage for linear motion comprising micrometer head operatively connected to properly constrained and guided movable plate, preferably involving means selected from ball guides, roller guides, linear guides or bearings, or assembly pre-loading of machined plates of the stage with the above said end connector and radial bearings as a joint means.
13. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 11 comprising stages selectively provided with one or more of (a) hollow path provided through the stages preferably including selective bearings for such path, (b) tapping/holes in the fixed frame assembly such that angular stage or combination stage can be mounted on another stage or on any other structure for various optical set-ups, (c) constrained rotatable and fixed link arrangement with pre-loading of bearings adapted to reduce coupled angular motions.
14. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 11 comprising mounting of linear motion stage on the angular motion stage or vice versa.
26

15. A system for precision angular motion mechanism for alignment and positioning
of optical elements as claimed in anyone of claims 1 to 14 wherein said
angular stage comprise a range of 0 to 22° involving 25 mm travel micrometer head and a range of 0 to 47° involving use of 50 mm travel micrometer head and further adapted for increase in range by (a) reducing overlapping length of end connector and/or (b) reducing the distance between the pivot of rotating link to self-aligning bearing;
angular stage has a resolution of 0.01° involving 10 micron resolution micrometer head and 0.001° involving 1 micron resolution micrometer head and further adapted for increase in resolution by (a) involving differential screw micrometer head and pre-loading the self-aligning bearing with any or combination of pre loading methods preferably reducing the radial clearance, spring pre-loading and /or (b) increasing the distance between pivot of rotating link to self-aligning bearing and gaining more resolution for the same resolution micrometer head and use of pre-loading as said above.
16. A system for precision angular motion mechanism for alignment and positioning
of optical elements as claimed in anyone of claims 1 to 14 wherein a through
hole is provided in the axis of rotation of the rotary link to thereby provide a
clear path for X-rays/light.
17. A system for precision angular motion mechanism for alignment and positioning of optical elements as claimed in anyone of claims 1 to 16 comprising mechanized feed control of the micrometer head preferably comprising a stepper motor supported with respect to the fixed frame link.
18. A translation stage for precision linear motion for linear positioning and alignment of optical elements comprising:
a mounting block;
a micrometer clamp tightened to the said mounting block and adapted to
clamp the micrometer head;
a movable slide supported on the said mounting block and guided by guide
blocks to facilitate its sliding movement and further adapted for linear
positioning and alignment of optical elements;
a bearing block tightly fastened to the movable slide,
27
21MAR 2007

a micrometer end connector providing a non slip operative connection there between the spindle of micrometer head and a rotary bearing of the bearing block;
said desired precise linear motion of the optics for monochromator mounted on the translation stage obtained by the motion of the said micrometer spindle, where the said motion is transferred through tightly secured end connector to the rotary bearing of the bearing block to facilitate sliding motion of the movable slide fastened to the bearing block which is adapted to slide linearly, restrained and guided by said guide blocks.
19. A translation stage as claimed in claim 18 comprising of light weight components and compact in size for easy handling.
20. A system for precision angular motion mechanism for alignment and positioning of optical elements and a translation stage substantially as herein described and illustrated with reference to the accompanying figures.
Dated this 23rd day of July 2005.
Anjan Sen
Of Anjan Sen & Associates (Applicant's Agent)
28

Documents:

881-mum-2005-cancelled page(27-11-2006).pdf

881-mum-2005-claim(granted)-(27-11-2006).pdf

881-mum-2005-claims(granted)-(27-11-2006).doc

881-mum-2005-claims.doc

881-mum-2005-claims.pdf

881-mum-2005-correspondence(24-08-2007).pdf

881-mum-2005-correspondence(ipo)-(05-01-2007).pdf

881-mum-2005-correspondence-received-230705.pdf

881-mum-2005-correspondence-received-241106.pdf

881-mum-2005-correspondence-received-290805.pdf

881-mum-2005-correspondence-received-291205.pdf

881-mum-2005-description (complete).pdf

881-mum-2005-drawing(27-11-2006).pdf

881-mum-2005-drawings.pdf

881-mum-2005-form 1(25-07-2005).pdf

881-mum-2005-form 1(27-11-2006).pdf

881-mum-2005-form 18(02-01-2006).pdf

881-mum-2005-form 2(granted)-(27-11-2006).doc

881-mum-2005-form 2(granted)-(27-11-2006).pdf

881-mum-2005-form 3(21-03-2007).pdf

881-mum-2005-form 9(30-08-2005).pdf

881-mum-2005-form-1.pdf

881-mum-2005-form-18.pdf

881-mum-2005-form-2.doc

881-mum-2005-form-2.pdf

881-mum-2005-form-26.pdf

881-mum-2005-form-3.pdf

881-mum-2005-form-9.pdf

881-mum-2005-petition under rule 137(28-11-2006).pdf

881-mum-2005-power of attorney(25-07-2005).pdf

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Patent Number

209080

Indian Patent Application Number

881/MUM/2005

PG Journal Number

42/2008

Publication Date

17-Oct-2008

Grant Date

20-Aug-2007

Date of Filing

25-Jul-2005

Name of Patentee

THE SECRETARY DEPARTMENT OF ATOMIC ENERGY

Applicant Address

GOVT.OF INDIA, ANUSHAKTI BHAVAN, CHATRAPATI SHIVAJI MAHARAJ MARG, MUMBAI,

Inventors:

#	Inventor's Name	Inventor's Address
1	SHANKAR BOMMAGANTI GOWRI	SCIENTIFIC OFFICER-C, X-RAY OPTICS SECTION, SYNCHROTRON UTILISATION DIVISION, ADL BUILDING, CENTRE FOR ADVANCED TECHNOLOGY, INDORE 452013

PCT International Classification Number

G02B 7/182

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA