Title of Invention

DISK CAM FOR THE ECCENTRIC MACHINE OF A WEAVING MACHINE

Abstract

An optimized eccentric machine (3) comprises disk cams (6) having a peripheral surface (8) setting different laws of motion in different sectors. The laws of motion are applied to a main phase of movement (a) and to end phases (b, c) in which the shaft covers, at best, a smaller distance of its movement. This partial distance preferably accounts for less than 50% of the total movement or total stroke of the shaft. The laws of motion of the different phases of movement or sectors of the disk cam (6) are defined in such a manner that the first and second derivations of the laws of motion of adjacent sectors coincide at the transition points.

Full Text

28 March 2007 GROZ P 202 EP abet Keyword: E-Cam Groz-Beckert KG, Parkweg 2, 72458 Albstadt, Germany Disk Cam for the Eccentric Machine of a Weaving Machine The invention relates to a disk cam for an eccentric machine, as well as to such an eccentric machine. In most cases, several heald shafts, each comprising many parallel-arranged healds having thread eyes through which the warp threads are passed, are used for shed formation on weaving machines. For shed formation, the heald shafts are rapidly moved up and down. To achieve this, shaft drives that are referred to as shaft machines or eccentric machines are used. In so doing, eccentric machines use the rotary motion of a drive shaft in order to generate an oscillating back-and-forth movement, from which the up-and-down movement of the heald shafts is derived. Thus, high weaving speeds can be achieved. During the up-and-down movement of the heald shafts high dynamic loads are generated on the heald shafts, its parts, the shaft machine and the connecting rod assembly between heald shaft and shaft machine. -1- Document DE 103 43 377 discloses a shaft machine that allows individual shaft drives to be added or removed. This is achieved by means of a ratchet mechanism. As a result of this, heald shafts can be selectively held in the upper or lower reversal region while other shafts continue to move. In so doing, the design is such that the shafts do not come to a full movement. As a result of this, a reduction of the accelerating forces acting on the heald shaft is achieved in the reversal regions. The movement in the reversal regions and the movement between the reversal regions, in so doing, occurs consistent with different laws of motion. The transitions between the law of motion in the reversal region and the law of motion between the reversal regions is such that the first time-derivation of the shaft movement is the same according to both laws of motion. The different laws of motion are implemented on different disk cams, whereby, by means of the ratchet mechanism, a switch is performed from one disk cam to the other. Such shaft machines are relatively complex and expensive. Various shed formation devices are used for shed formation in weaving mills. These are so-called shaft machines, eccentric machines and jacquard machines. Neither eccentric machines nor jacquard machines comprise ratchet mechanism for adding and removing individual eccentric disks. Considering these machines, however, it is important that weaving speeds be increased and that stresses be minimized. Considering this, the object of the invention is to provide a shed formation device or a component suitable for this shed formation device, said component being used to increase the operating speed of the weaving machine without excessively stressing the parts of the weaving machine. This object is achieved with the disk cam in accordance with Claim 1: The disk cam in accordance with the invention represents the sought component. Said component is preferably in permanent driving connection with a continuously moving drive shaft and is subject to at least two different laws of motion on its cam surface or peripheral surface. While one law of motion defines the sequence of motions between the upper and the lower reversal regions of a heald shaft, the other law of motion describes the movement of the heald shaft in its reversal regions. The laws of motion are selected such that the first and second time derivations of the two laws of motion coincide. This eliminates shocks and jerks where transitions of the laws of motions occur. As a result of this, vibrations and wear are -2- reduced or largely avoided. As a result, the forces and stresses on the shaft drive and on the heald shaft are reduced. Consequently, an existing shed formation device, e.g., an eccentric machine, provided said machine is equipped with the inventive disk cams, can be operated at higher rates of speed, without being damaged and without causing damage to the connecting rod assemblies, heald shafts, their parts and healds. A disk cam in accordance with the invention comprises several phases of movement. The phase of movement (a, a') represents the main phase of movement (sequence of motions between the upper and lower reversal regions), the phase of movement (b) represents the upper end phase (upper reversal region), and the phase of movement (c) represents the lower end phase (lower reversal region). In the phases of movement (b, a, and c), the heald shaft moves through its stroke region performing a downward movement, in the phases of movement (c, a', and b), the heald shaft moves through its stroke region performing the upward movement. The main phase of movement (a, a'), as well as the phases (b and c), represent phases of movement in which the heald shaft moves through at least one part of the distance that is to be traveled. For example, they can generate an up-and-down movement of the heald shaft within a reversal region. However, they can just as well generate a movement, which, as usual, comes to a short-time stop and remains stopped, whereby, in such a case, the transition between the laws of motion of the phases (b) and (a), or (a) and (c), or (c) and (a'), or (a') and (b), respectively, occurs while the first and second distance derivations or time derivations of the laws of motion are the same. This provides a jerk-free and shock-free transition of the shaft movement from one phase of movement to the next. By varying the lengths of the phases of movement and by selecting the respective laws of motion, shaft movements can be generated which stress the heald shafts significantly less and permit higher weaving machine rotational speeds. In so doing, the main part of the movement of the phase (a, a') can be optimized, without having to take into consideration the requirements of the movements during the phases (b) and (c). Preferably, the phase of movement (a, a') is configured so as to represent the main phase, in which the heald shaft moves through at least 50% of its stroke. In phases of movement (b) and (c), i.e., in the reversal regions, the heald shaft completes its stroke and comes to a stop, or it moves through a waiting reciprocating motion. Different laws of motion apply in the main phase and in the end phase. The end phases, both representing a reversal region, may have different lengths of time and also different stroke lengths. The may be set -3- different from each other, as long as the transitions to the main phase are corresponding in the first and second derivations of the respective laws of motion. During operation, a heald shaft performs a movement that is upward and downward. The aforementioned movement described as a stroke can apply to the downward movement, as well as to the upward movement, of a heald shaft. A disk cam in accordance with the invention, said disk cam defining an upward movement and a downward movement of a heald shaft, consists of at least four phases of movement, the phases of movement (b), (c), (a) and (a'). Depending on the flat textile product to be produced, a disk cam in accordance with the invention may comprise several of the above-described phases of movement. It is also conceivable that the phases of movement are identical or partially identical. The disk cam, as in otherwise common shed formation devices, preferably is associated with a complementary disk cam. The latter has a profile that is complementary to the disk cam. Additional details of advantageous embodiments of the invention are obvious from the drawings, the description or the claims. The drawings show an exemplary embodiment of the invention. They show in Figure 1 a schematic view of a heald shaft with an eccentric machine for driving said heald shaft; Figure 2 a disk cam and a cam-following means of the eccentric machine in accordance with Figure 1; Figure 3 a diagram of the contour of the disc cam in accordance with Figure 2; Figure 4 a highly excessively elevated illustration of a modified embodiment of a disk cam; and, -4- Figure 5 a diagram of the laws of motion of the disk cam in accordance with Figure 4. -5- Figure 1 shows a heald shaft 1 that is driven, via a rod assembly 2, by an eccentric machine 1 so as to move up and down in an oscillating manner. The vertical direction is indicated as the x-direction by an arrow. The eccentric machine 3 has, on its outlet, a rocker 4 which is connected to the rod assembly 2. The rocker 4 performs a back-and-forth oscillating movement as indicated by arrow y in Figure 4, said movement being derived from the rotation of a main shaft 5. This shaft is provided with a drive, for example, an electric motor, and rotates at an essentially constant rotational speed. Seated on the main shaft 5 is a disk cam 6, as is depicted in Figure 2. Its center of rotation 7 is defined by the main shaft 5. Said shaft has a peripheral surface 8 with a radius r to the center of rotation 7, this being a function of the angle of rotation a. A cam-following means 9, for example, having the configuration of a roller 10, that is supported by a pivoting lever 11 abuts against this peripheral surface 8. Said pivoting lever can be pivoted about a fulcrum 12 (indicated by arrow z in Figure 3), whereby its pivoting motion is transmitted to the rocker 4 via a not specifically illustrated transmission connection. The peripheral surface 8 has several sections a, a', b, c, that define different "laws of motion". In so doing, laws of motion are understood to mean a function r(oc). In addition, the radii of the laws of motion b and c are located in the regions that do not overlap each other. For the selection of the laws of motion for the regions a, a', b and c, reference is made to Figure 3. Figure 3 shows the stroke of the heald shaft (vertical) and the time (horizontal). The region Bl shows the stroke section in the phase of movement (c) (lower reversal region. The region B2 shows the stroke section in the phase of movement (b) (upper reversal region). The region B3 shows the stroke section in the phases of movement (a) and (a') (movement region between the reversal regions). The stroke regions B] and B2 of the angle sections b and c do not overlap. They are separated from each other by a region B3 that is associated with the angular region a or a'. The regions a, a', b, c represent phases of movement for the cam-following means 9 and thus for the heald shaft 1. The laws of motion are different in these phases of movement, whereby the transitions between the individual phases of movement b —> a, and a —> c, and c —» a', and a' —> b are configured such that the derivations of the first and second order of the adjacent laws of motion that extend into each other are the same. An inventive disk cam in accordance with Figures 2 and 4 may use any laws of motion as defined by any -6- mathematically expressible laws of motion, e.g., sine, cosine, polynomials, etc., and sums thereof. A disc cam may also use laws of motion that cannot be analytically described. Considering the aforementioned transition conditions, the cam-following means 9 - referring to an appropriately designed disk cam having sections a, a', b, c - performs a shock- free and jerk-free sequence of motions. The section a' may represent a main phase of movement that is inverse to the section a. While, referring to the aforementioned exemplary embodiment, the phases of movement b and c provide a movement that comes almost to a stop at the outer ends of the reversal regions Bi and B2, also other laws of motion may be provided as illustrated by Figure 5. The corresponding disk cam is shown excessively high in Figure 4. The laws of motion in the phases of movement b and c are assumed to be harmonic functions, whereby they need to have neither a constant amplitude nor a constant frequency. In this case, the heald shaft 1 performs a reciprocating movement in the reversal regions. Referring to Figure 5, this reciprocating movement is shown in the reversal regions b and c. The above-described conditions in the region of the transitions of the various movement regions also apply to an exemplary embodiment of a disk cam in accordance with Figure 4. Consequently, transition regions without jerks and shocks are created. An eccentric machine comprising disk cams of the above-described type permits an optimization of the sequence of movements of the heald shaft 1. Said heald shaft's acceleration and its deceleration can be optimized. Furthermore, said heald shaft's speed can be maximized in the phases of movement a and a', without excessively stressing the elements of the heald shaft or the elements of the eccentric machine 3. In so doing, the time intervals available for weft insertion can be maximized even at high rotational speeds. An optimized eccentric machine 3 comprises disk cams 6 having a peripheral surface 8 setting different laws of motion in different sectors. The laws of motion are applied to a main phase of movement a, a' and to end phases b, c, in which the shaft covers, at best, a smaller distance of its movement. This partial distance preferably accounts for less than 50% of the total movement or total stroke of the shaft. The laws of motion of the different phases of movement or sectors of the disk cam 6 are defined in such a manner that the first and second derivations of the laws of motion of adjacent sectors coincide at the transition points. -7- List of Reference Numbers: 1 Heald shaft 2 Rod assembly 3 Eccentric machine 4 Rocker 5 Main shaft 6 Disk cam 7 Center of rotation 8 Peripheral surface 9 Cam-following means 10 Roller 11 Pivoting lever 12 Fulcrum -8- Patent Claims: 1. Disk cam (6) for a shed formation device (3) of a weaving machine, whereby the disk cam (6) has a center of rotation (7) and a peripheral surface (8) with a variable radius (r) in order to impart a cam-following means (9) in contact with the peripheral surface (8) with a stroke movement when said disk cam is rotating; the peripheral surface (8) is divided into a first section (a), a second section (b), a third section (a') and a fourth section (c), said sections exhibiting different phases of movement that are consistent with a heald shaft (1) that is connected to the cam- following means (9); the different sections (a, a', b, c) are subject to different laws of motion; and, the different laws of motion, at their adjoining points, are the same in the first and the second derivations. 2. Disk cam in accordance with Claim 1, characterized in that the shed formation device is an eccentric machine (3). 3. Disk cam in accordance with Claim 1, characterized in that the shed formation device is a jacquard machine. 4. Disk cam in accordance with Claim 1, characterized in that the first phase of movement (a) and the third phase of movement (a') represent a main phase in which the heald shaft moves at least 50% of its stroke distance. 5. Disk cam in accordance with Claim 1, characterized in that the second phase of movement (b) and the fourth phase of movement (c) have different lengths in time. 6. Disk cam in accordance with Claim 1, characterized in that the second phase of movement (b) and the fourth phase of movement (c) have different stroke lengths. -9- -10- 7. Disk cam in accordance with Claim 1, characterized in that the second phase of movement (b) and/or the fourth phase of movement (c) generate at least one reversal of movement. 8. Disk cam in accordance with Claim 1, characterized in that the second phase of movement (b) and/or the fourth phase of movement (c) generate a reciprocal movement of the heald shaft (1). 9. Disk cam in accordance with Claim 1, characterized in that the second phase of movement (b) and the fourth phase of movement (c) satisfy different laws of motion. 10. Disk cam in accordance with Claim 1, characterized in that the disk cam is associated with a complementary disk cam. 11. Eccentric machine comprising a disk cam in accordance with one of the previous Claims. 12. Jacquard machine comprising a disk cam in accordance with one of the previous Claims. 13. Weaving machine comprising a shed formation device in accordance with one of the previous Claims. An optimized eccentric machine (3) comprises disk cams (6) having a peripheral surface (8) setting different laws of motion in different sectors. The laws of motion are applied to a main phase of movement (a) and to end phases (b, c) in which the shaft covers, at best, a smaller distance of its movement. This partial distance preferably accounts for less than 50% of the total movement or total stroke of the shaft. The laws of motion of the different phases of movement or sectors of the disk cam (6) are defined in such a manner that the first and second derivations of the laws of motion of adjacent sectors coincide at the transition points.

Documents:

00486-kol-2008-abstract.pdf

00486-kol-2008-claims.pdf

00486-kol-2008-correspondence others.pdf

00486-kol-2008-description complete.pdf

00486-kol-2008-drawings.pdf

00486-kol-2008-form 1.pdf

00486-kol-2008-form 2.pdf

00486-kol-2008-form 3.pdf

00486-kol-2008-form 5.pdf

486-KOL-2008-(09-07-2013)-ABSTRACT.pdf

486-KOL-2008-(09-07-2013)-CLAIMS.pdf

486-KOL-2008-(09-07-2013)-CORRESPONDENCE.pdf

486-KOL-2008-(09-07-2013)-DESCRIPTION (COMPLETE).pdf

486-KOL-2008-(09-07-2013)-DRAWINGS.pdf

486-KOL-2008-(09-07-2013)-FORM-1.pdf

486-KOL-2008-(09-07-2013)-FORM-2.pdf

486-KOL-2008-(09-07-2013)-FORM-3.pdf

486-KOL-2008-(09-07-2013)-FORM-5.pdf

486-KOL-2008-(09-07-2013)-OTHERS.pdf

486-KOL-2008-(09-07-2013)-PA.pdf

486-KOL-2008-(09-07-2013)-PETITION UNDER RULE 137.pdf

486-KOL-2008-CORRESPONDENCE 1.2.pdf

486-KOL-2008-CORRESPONDENCE OTHERS 1.2.pdf

486-KOL-2008-CORRESPONDENCE OTHERS-1.1.pdf

486-kol-2008-form 18.pdf

486-KOL-2008-OTHERS.pdf

486-KOL-2008-PA.pdf

486-KOL-2008-PRIORITY DOCUMENT.pdf

486-KOL-2008-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf