Title of Invention

DETECTOR FOR DETECTING A YARN BOBBIN CHANGE IN A YARN PROCESSING SYSTEM

Abstract

The present invention relates to a detector for detecting a yarn bobbin change in a yarn processing system, the detector having a movably supported element which is movable between a loading position and a detection position, a yam positioning device for positioning the yarn in the detector to load the detector with the yarn until the bobbin change takes place, at least one detection member within the moving path of the element for responding with a signal to a relative position or a relative position change of the element, and a force generator imparting a force on the element in at least the moving direction of the element, the element being movable along a moving path during the bobbin change, characterized in that the force generator imparts the force on the element in the moving direction of the element from the loading position to the detection position, and that the positioning device comprises a yarn clamping area extending crosswise to the moving path of the element, having a passing slot for the element, the yarn clamping area serving to secure the yam across the passing slot and in moving direction of the element from the loading position to the detection position ahead of the element prior to a yam bobbin change.

Full Text

DETECTOR FOR DETECTING A YARN BOBBIN CHANGE IN A YARN PROCESSING SYSTEM The invention relates to a detector according to the preamble part of claim 1. The detector known from EP 0 454 199 A has an asymmetric pivtotably supported angled lever having two arms. Due to the asymmetric design, a force generator for generating force is integrated into the lever which force brings one of the amis, constituting an element, into the loading position and holds the arm In the loading position. The positioned yam is situated within a receiver behind the arm such that the opening of the receiver is blocked by the amn. During a bobbin change, the yam is pulled out of the opening such that the yam displaces the ami into the detecting position and such that the yam is freed. The angled lever actuates a switch when reaching the detecting position. The switch emits the signal for the occurred bobbin change. An auxiliary device secures the pivoted angled lever firmly such that the arm again blocks the opening of the receiver. When loading the detector, the angled lever is pivoted via the arm by the yam until the yam again has reached the position behind the ami and until the angled lever is again in the loading position. Since the yam has to overcome the force acting on the angled lever during the bobbin change, and then in some cases will be significantly deflected, a considerable tension peak is generated in the yam which might be the reason for a yam breakage. in practice, furthermore, an opto-electronic detector of this kind is known which has disk brakes at both sides ot a mouth which is open at one end. The disk brakes constitute in combination with the mouth the positioning device for the yam. The disk brakes are arranged in relation to a light bamer penetrating through the mouth such that the positioned yam is held at the side of the light bamer which is remote from the opening of the mouth. During a bobbin change, the yam is released from the disk brakes and is pulled through the light barrier. The temporary and rapid shadowing of the light barrier generates a signal indicative of the bobbin change. For loading the detector, the yam is inserted manually into the disk brakes. As this movement is earned out slowly, e.g. by means of a filter, the generation of a signal is then suppressed. In some cases, this slow loading movement of the yam through the light banier is converted into another signal confirming that the detector has been loaded correctly. The opto-electronic detector suffers with its operational safety from unavoidable contamination and has to be individually adjusted to different yam qualities and/or yam thicknesses. It is an object of the invention to provide a detector as mentioned at the beginning which is reliable in operation and at which the danger of a yam breakage is eliminated during the bobbin change. This object is achieved by the features of claim 1. In contradiction to the known principle of the mechanic detector as described at the begining, namely to displace the element during the yam bobbin change by the yam and counter to the acting force, the detector according to the invention is designed such that the yam only has to overcome the holding force in the yam clamping area during the yam bobbin change. The holding force can be adjusted so low that delicate yam material will not be damaged during the yam bobbin change and such that it is just high enough to hinder any movements of the element supported by the yam under the acting force. The element only can follow the released yam under the action of the force without the yam actively moving the element or without undesirable yam deflection at the element. The yam which is in the process of being released during the yam bobbin change allows that the element automatically is moved by the acting force from the loading position where it is blocked by the yam into the detection position. In this manner, the danger of a yam breakage is eliminated. During the yam bobbin change, the yam moves out of the yam clamping area substantially in the same direction in which also the element, at least with a movement component moves towards the detection position. Expediently, the element is a substantially straight pivot lever having two arms which lever responds with one arm to the movement of the yam during releasing the yam from the yam clamping area and which follows the yam which moves away while the pivot lever generates the yam bobbin change indicating signal by the other arm. In an expedient embodiment, electronic components for processing the signal are hermetically shielded in the housing of the detector against the exterior and are provided e.g. on a printed circuit board. By this measure contamination like lint, dust and in some cases avivage which are unavoidable in the technique of weaving, cannot gain a disturbing influence on the contamination sensitive electronic components. In a preferred embodiment, at least one leaf spring is arranged in the yam clamping area which leaf spring can be penetrated by the element The leaf spring secures the yam very gently and precisely at a desired position on a resting surface of the housing of the detector. Altenatively, at least one holding device e.g. a disk brake, which is arranged sideways of the moving part of the element, can be provided in order to define the yam damping area. Expediently. a permanent magnet is provided in the element. The permanent magnet, preferable, may fulfill a dual function. At one side, the permanent magnet cooperates with a stationary iron body in order to constitute the force generator which generates the force which lets the element trail behind the yam while the yam is in the process of being released. At the other side, the permanent magnet may co-act with a stationary Hall sensor constituting the detection member used for emitting a signal. The signal is generated as soon as the permanent magnet is situated close to the Mall sensor or when the permanent magnet moves away from the Hall sensor or has already been moved away. The signal is processed for indicating an occurred change and/or in some cases for indicating Xnat the detector has been loaded with the yam. Alternatively, it is possible to provide a further detection member for cooperation with the pemianent magnet or with another transducer which then generates a loading signal. Alternatively, the force generator could be at least one spring actuating the element. In this case, the spring force should be oriented in the direction in which the element moves from the toading position into the detection position. Expediently, the iron body is positioned so that the force is the strongest in the detection position and is the weakest in the loading position. This is advantageous because the yam is only loaded weakly by the element in the loading position which, however, will safely reach the detection position with the increasing force after the yam has teen released. Particulariy advantageous is a straight pivot lever which has two amns and is weight balanced in the pivot bearing. For this reason, the detector functions equally inespective of the mounting position in space. Finally, it is expedient when the element has an active length at the end cooperating with the yam thanks to which the yam cannot be moved in any case past the element. In this way It is assured by predetermined geometric relations that the yam cannot come in any case behind the element. tn an advantageous embodiment, the element is a bending spring which is preloaded in the loading position by the force. Preferably, the bending spring Is a leaf spring. This embodiment is structurally very simple and reliable since the element does not need a special support for the operative movements. As a leaf spring is expedient for positioning the yam in the clamping area in any case, in a further advantageous embodiment the bending spring forming the element may even be a unitary part of the leaf spring for securing the yam in the clamping area, more in detail, on at least one resting surface. In this case, the leaf spring has a dual function such that the number of parts of the detector can be reduced. Expediently, the leaf spring has two outer tines by which tines the yam is positioned in the clamping area of the detector at both sides of the element constituted by the bending spring. The bending spring may then be an intermediate tine of the same leaf spring which tine is secured at the housing under bending preload, preferably at the inlet of a mouth leading to the clamping area. The outer tines only need to move for an extent corresponding to the yam thickness relative to the resting surface while the bending spring formed by the intermediate tine additionally can move along the movement path into the detection position. The preload by which the outer tines and the bending springs are loaded stems expediently from a common fixation location or tensioning location of the leaf spring. Basically, a single outer tine would be sufficient to reliably secure the yam. Expediently, the outer tine is broader than the Intenneditate tine which intemediate tine forms the bending spring. For this reason, the outer tine has more bending stiffness than the bending spring. Basically, it may be expedient to design the bending spring and the outer tine with different preloads and/or spring properties to adapt them to the differing topics. The outer tine has the task of positioning the yam in the clamping area as gently as possible, but reliably. The bending spring, in contrast has the task of carrying out the movement toward the detection position during the release of the yam from the clamping area and to load the yam as gently as possible while the yam is positioned in the clamping area. Different preloads and/or different spring properties reliably fulfill these different tasks. It has to be noted that, in addition, the bending spring should have a preload and/or a spring property such that the bending spring, with the permanent magnet provided at the bending spring, does not perfomi nervously. It may be expedient to form the bending spring in the transition region to the leaf spring with a narrowed portion such that the bending spring will perfomi relatively softly. Additionally or alternatively, each outer tine could be stiffened against bending by at least one longitudinal corrugation or another stiffening structure such as e.g. a housing stop with the form of a rib which preloads the outer tine and in some case shortens the active spring length of the outer tine. Embodiments of the invention will be explained with the help of the drawing. In the drawing is: Figure 1 schematically a processing system comprising a detector for a yam bobbin change, Figure 2 a longitudinal section of the detector, with a second embodiment indicated in dotted lines, Figure 3 a further embodiment of the detector in a longitudinal section. Figure 4 a detailed top view belonging to Figure 3, and Figure 5 a further detail belonging to Figure 3. In a yam processing system S in Figure 1 two yam bobbins B1, B2 which carry the same yam Y are mounted e.g. at a bobbin creel 1. A yam processing facility F, e.g. a feeding device, pulls the yam Y from the respective yam bobbin B1, 82. The end of the yam Y on one yam bobbin 81 is connected by a knot to the front end of the yam Y on the other yam bobbin B2 (pigtail). E.g. at the bobbin creel 1, a detector D is mounted in which the connecting section of the yam Y is positioned. When the yam Y is consumed from the yam bobbin B1 a yam bobbin change has to take place to the second yam bobbin B2. During the change, the connecting section Is pulled out of the detector D before subsequently the yam Y Is withdrawn from the second yam bobbin 82. During this change, the detector D generates signal I which indicates the occurred change. In some case, the detector D may be designed so that during loading the detector with the yam Y a similar or another signal is emitted which represents the loading process. Loading has the meaning that the connecting yam section Is inserted into and positioned in the detector D. In the longitudinal section of the detector D In Figure 2 It can be seen that a mouth 4 is provided at a lower side of a housing 3. The mouth 4 Is open to one end (to the left side). Within the extension of the mouth 4 a positioning device 5 for the yam Y is provided. The positioning device 5 comprises a locally defined yam clamping area 6 In which the yam Y Is secured by after during loading the detector D (as shown) with the yam Y. The positioning device 5, having the yam clamping area 6, e.g. consists of a leaf spring C provided within the mouth 4 (shown in solid lines). The leaf spring C has a e.g. passing slot (not shown). The leaf spring can be pressed by preload against resting surfaces 4a. In another case, the positioning device 5 may comprise at least one disk brake 6* which is located at the side of a slot 11 of the bottom of the mouth 4. In yet another case, the positioning device 5 may be a holding device operating with a force-fit. A detection member 7, e.g. a Hall sensor, is stationarily provided in the housing 3, e.g. on a printed circuit board H. Furthermore, a stationary iron body 8 Is an-anged distant from the detection member 7. In the housing 3, a mechanically moveably supported element E is provided for co-action with the yam Y with the detection member 7 and with the iron body 8. In the shown embodiment, the element E is a straight pivot lever 9 having two arms 9a, 9b. The pivot lever 9 can be pivoted about a pivot axis 10, preferably within a limited pivot region. A permanent magnet M Is arranged In the arm 9a close to the amn end. The permanent M both cooperates with the detection member 7 (the Hall sensor) and also the iron body 8, The arm 9b at the other side of the pivot axis 10 in this case dives in each pivot position of the pivot lever 9 into the longitudinal slot 11 in the housing 3 and also into the leaf spring C. The pivot lever 9 is formed such that it is at least substantially weight balanced in relation to the pivot axis 10 and despite the presence of the permanent magnet M. The iron body 8 and the permanent magnet M commonly constitute a force generator which imparts a force 13 on the element E about the pivot axis 10 and in the direction of the shown arrow The pivot lever 9 can be pivoted between the shown loading position L where the permanent magnet M is positioned dose to the detection member 7 and a detecting position P indicated by a dotted line. The force 13 indicated by the arrow is the weakest in the shown loading position but becomes the strongest in the indicated detection position P. Alternatively or additionally, the element E also could be loaded by a spring in the same direction (similar to the embodiment of Figures 3 and 4). During loading the detector D the yam Y is brought into the shown position and is secured by the leaf spring C on the resting surfaces 4a in the yam clamping area 6 such that the pivot lever 9 is moved to the shown loading position and will contact the yam Y with the then relatively weak force 13. The positioned and secured yam Y then forms an obstacle hindering the pivot movement of the pivot lever 9 towards the detection position P. During the yam bobbin change the yam Y is released from the yam clamping area 6 or 6' and is pulled out of the mouth 4 along the resting surfaces 4a in the direction of an arrow 12. The force 13 then pivots the pivot lever 9 into the detection position P. When the detection position is reached, or even before, the signal i Is emitted. The pivot lever 9 remains in the detection position P until the next loading process. Expediently, the pivot lever 9 is a light-weight plastic shaped part. The penetration depth of the arm 9a in the longitudinal slot 11 is chosen so that within the limited pivot range of the pivot lever 9 the yam Y cannot move within the mouth 4 past the amn 9b. In a not shown alternative solution, the arm 9a could be scanned opto-electronically within the interior of the housing 3 and such that the scanning means are shielded against contamination. Furthermore, a further detection member could be associated to the pivot lever 9 for indicating or confirming the loading process. In an alternative solution, a runner or a shoe could be provided at the end of the arm 9b which runner or shoe is lifted In the loading position L by the yam Y and gently rests on the yam Y. The runner or shoe could have a downwardly extending catching stop at the right side. In another alternative solution, a convex resting surface could be formed at the arm 9b which resting surface contacts the yam Y in the loading position L with the force 13. In the embodiment of Figures 3 and 4, the element E canying the permanent magnet M is designed as a bending spring 18 which bending spring e.g. is a intermediate tine of the leaf spring C, the outer tines 16, 17 of which serve for positioning the yam Y in the damping area 6 of the positioning device 5. Figure 4 is a top view of the leaf spring C which is secured at the housing 3 (Figure 3) between a support 22 and a retainer 23 of a tensioning body 34 in fixation locations 15. The leaf spring C is secured under preload. The outer tines 16, 17 which are broader than the intemediate tine, abut on the resting surfaces 4a in the mouth 4, in some cases with a pre-load (Indicated In Figure 3 in dotted lines) as long as no yam Y is positioned below. The electronic components of the detector D, which are not shown in detail and which may be arranged on a printed circuit board H, are hennetically shielded to the exterior. The detection member 7, e.g. a Hall sensor, as well is provided such that it is shielded or covered and is actuated through a housing wall (which e.g. consists of plastic material) by the pemianent magnet M. Alternatively, and as indicated in Figure 3 in dotted lines, the detection member T may even be provided in the proximity of the detection position P of the pending spring 18. The detection member 7, 7' also could be used to confirm the loading process. The longitudinal slot 11 is open to the lower side so that collected lint can fall out downwardly. The bending spring 18 may be somewhat shorter than the outer tines 16, 17 such that the bending spring 18 moves from the position shown in full lines in the direction of the arrow 12 during the yam bobbin change into the longitudinal slot 11 into the detection position P after the release of the yam Y, and in particular, propelled by the force 13 and along a lateral wall 25' of the longitudinal slot 11. The detection position P of the bending spring 18 could even be defined by a stop (not shown). The function of the detector in Figure 3 is the same as of the detector of Figure 2. The leaf spring C is designed in Figure 4 such that the bending spring 18, as the intermediate tine, is either essentially of constant width over its length or, as indicated in dotted lines, is formed with a narrowed portion 21 defined by cutouts 20 which give the bending spring 18 another bending behavior or another preload than is present in the outer tines 16,17. The tines 16,17 may even be stiffened by longitudinal corrugations or other stiffening stnjctures 25 (indicated in dotted lines) such that the outer tines 16, 17 have another preload or another bending behavior than the bending spring 18. The leaf spring C can be formed by stamping or laser cutting a basically rectangular leaf spring blank 14. Alternatively, it is possible to provide one outer tine 16 or 17, or to form one or two outer tines e.g. by a leaf spring having a larger wall thickness and/or stiffness than the second and softer leaf spring or bending spring 18 which is separate and forms the element E. In a further altematlve (not shown), the bending spring 18 could be a bending arm or bending wire (spring steel wire) which is soldered into the cutout between the outer tine 16, 17 in order to achieve the different preloads or different bending behaviors for the different tasks. This is because the outer tines 16, 17 have to fulfill a clamping task while the bending spring 18 should load the yam Y as weakly as possible and also should deflect the yam Y as little as possible and should only reliably carry out the stroke from the loading position L into the detection position P. The inner end of the mouth 4 is designed such that it forms a sort of limiter for the positioning of the yam Y. Instead of a Hall element as the detection member, another electronic member could be used which responds by a signal to the presence or the proximity or the movement of a metallic txxly or of a magnet. The permanent magnet M, in the embodiment of Figure 3, could constitute a ballast weight and could, thus, assist in generating the force 13 which moves the bending spring 18 or the element E from the loading position L into the detection position P. A rib-shaped housing stop 26 is provided in Figure 5 which supports the outer tine 16,17 e.g. close to the fixation location and which loads the outer tine 16, 17 while the intermediate tine, or the bending spring, extends without contact with the stop 26 to the resting surfaces 4a and such that for this reason the bending spring 18 behaves softer than the outer tines. CLAIMS Detector (D) for detecting a yam bobbin change in a yam processing system (S), the detector having a movably supported element (E) which is moveable between a loading position (L) and a detecting position (P), a yam positioning device (5) for positioning the yam (Y) until the bobbin change takes place, at least one detection member (7) within the moving path of the element (E) for responding with a signal 0) to a relative position or a relative position change of the element (E), and a force generator imparting a force (13) on the element (E) in at least the moving drection of the element, the element (E) being movable during the bobbin change, characterized in that the force (13) is oriented in the moving direction of the element (E) from the loading position (L) to the detection position (P), that the positioning device (5) includes a yam damping area (6) which is arranged in relation to the moving path of the element (E) from tiie loading position (L) into the detection position (D) such that the yam (Y) while positioned in the yam clamping area (6) forms an obstacle for the element (E) in the loading position (L) against a movement under the imparted force (13) until tine yam bobbin change takes place, and that the yam (Y), during the yam bobbin change, sets the element (E) free for an automatic movement under the force (13) from the loading position (L) into the detection position (P). Detector according to claim 1, characterized in that the yam (Y) is released from the positioning device (5) during the yam bobbin change substantially in the same direction in wfhich the element (E) moves under tiie force (13) from the loading position (L) to the detection position (P). Detector according to claim 1, characterized in that the electronic components for pnDcessing the signal (i) are hermetically shielded to the exterior within a housing (3) of the detector (D), and tiiat the electronic components e.g. are arranged on a printed circuit board (H). Detector according to claim 1, characterized In that tiie element (E) is a substantially straight pivot lever (9) having two arms (9a, 9b). Detector according to claim 1, characterized in that the yam clamping area (6) comprises either at least one leaf spring which can be passed by the element (E) or at least one leaf spring (C) which is placed at the side of the moving path of the element (E), or a yam clamp (6') or another force active yam-holding device. Detector according to claim 1, characterized in that the element (E) is equipped with a permanent magnet (M). Detector according to claim 1, characterized in that the pemianent magnet (M) constitutes the force generator in co-action with a stationary iron body (8). Detector according to claim 1, characterized in that the force generator Is a spring engaging at the element (E). Detector according to claim 6, characterized in that the pennanent magnet (M) co-acts with a stationary Hall sensor which constitutes the detection member (7). Detector according to claim 7, characterized in that the Iron body (8) is positioned with respect to the moving path of the permanent magnet equipped element (E) so that the force (13) acting at the element (E) is the strongest in the detection position (P) and is the weakest in the loading position (L). Detector according to claim 4, characterized in that the pivot lever (9) having the two anns is substantially weight balanced in relation to the pivot axis (10). Detector according to claim 1, characterized in that a mouth (4) is provided which is open sideways and towards one end, that the yam clamping area (6) is located within the mouth (4), and that the element (6) has an active length within the mouth (4) thanks to which the element (E) hinders a passage of the yam past the element (E) within the mouth, preferably within a limited pivot range of the element (E). Detector according to claim 1, characterized in that the element (E) is a bending spring (18), preferably a leaf spring, which is preloaded in the loading position (L) by the force (13). Detector according to claim 13, characterized in that the bending spnng (18) is a unitary part of a leaf spring (C) as well as serving for securing the yam (Y) In the yam clamping area (6) on at least one resting surface {4a). Detector according to claim 14, characterized in that the leaf spring (C) has at least an outer tine, preferably has two outer tines (16, 17), and additionally has the bending spring (18) in fonn of a intermediate tine, and that the leaf spring (C) is secured at the housing (3) under bending preload, preferably at the entrance of the rrxxjth (4). Detector according to claim 15, characterized in that the outer tine (15, 17) is broader than the intermediate tine. Detector according to claim 15, characterized in that the bending spring (18) and the outer tine (16,17) have different preloads and/or different spring properties. Detector according to claim 17, characterized in that the bending spring (18) has a narrowed portion (21) in the transition portion into the leaf spring (C). Detector according to claim 17, characterized in that the outer tine (16, 17) is stiffened against bending by at least one longitudinal conugation or a stiffening structure (25). Detector according to claim 17, characterized in that the outer tine (16, 17) is preloaded by an e.g. rib-shaped housing stop (26) which is preferably located close to the fixation location of the leaf spring (C).

Documents:

0317-chenp-2006 abstract duplicate.pdf

0317-chenp-2006 abstract.pdf

0317-chenp-2006 claims duplicate.pdf

0317-chenp-2006 claims.pdf

0317-chenp-2006 correspondence-others.pdf

0317-chenp-2006 correspondence-po.pdf

0317-chenp-2006 description (complete) duplicate.pdf

0317-chenp-2006 description (complete).pdf

0317-chenp-2006 drawings duplicate.pdf

0317-chenp-2006 drawings.pdf

0317-chenp-2006 form-1.pdf

0317-chenp-2006 form-18.pdf

0317-chenp-2006 form-26.pdf

0317-chenp-2006 form-3.pdf

0317-chenp-2006 form-5.pdf

0317-chenp-2006 pct search report.pdf

0317-chenp-2006 pct.pdf

0317-chenp-2006 petition.pdf

317-CHENP-2006 ABSTRACT.pdf

317-CHENP-2006 CLAIMS GRANTED.pdf

317-CHENP-2006 CORRESPONDENCE OTHERS.pdf

317-CHENP-2006 CORRESPONDENCE PO.pdf