DE2057383A1 - Thread clamping device - Google Patents

Description

Sulzer Brothers, Aktiengesellschaft, Winterthur / Switzerland

Thread clamping device

The invention relates to a thread clamping device, consisting of a carrier body, one on it attached thread clamp that can be closed by spring force, the two clamping jaws attached to the free end of the clamp arm possesses, 'as well as an opener for temporarily spreading the clamping jaws apart.

Fadenkleimnvorrichtungen of the type mentioned are generally used in a wide variety of textile machines, in which it is a matter of gripping a thread during the operation of the machine and bringing it into a certain position, or to execute a certain movement. For example, in the weft thread insertion devices of rapier weaving machines, such clamping devices in the weft thread feeder are known (e.g. according to one of the Swiss Patents Nos. 332 ¹ IOl or 335 ¹ OOO), each of which attaches the weft thread end to be inserted into the shed at the next weft insertion and to a clamping device (e.g. after

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one of the Swiss patents nos. 466,829 or 472,524). For this purpose, the thread feeder detects immediately after the weft insertion has been completed and after the subject change the weft-side end of the weft thread that has just been left outside the shed during the insertion The supply spool has been withdrawn and entered into the shed. This is a few millimeters in front of the shot-side Edge thread clamp J

./ the already entered thread length between feeder and the edge thread clamp cut from the following thread. This is done by the feeder for the rest of the weaving process held new weft thread end returned by the thread feeder in the direction of the supply bobbin up to the point at which this weft thread end for the next entry from another provided in the weft system Shooter clamp is accepted. A thread tensioner ensures that the weft thread remains taut even during this backward movement.

In order to ensure a safe transfer of the thread end from the feeder clamp to the shuttle clamp, the feeder must insert the thread end very precisely into the open shuttle clamp. This is done with the well-known Versions the position of the clamping jaws with the feeder clamp closed compared to the gripper clamp Set a special stop on which one of the two clamp arms of the feeder - it is under one slightly stronger spring preload than the other - is positively supported. The other, weaker bracket arm points

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no such stop or limit, so that the acting on him spring tension fully appears as a clamping force between the clamping jaws and serves to the To hold the thread. The structure and the arrangement of the feeder clamp are therefore not symmetrical with respect to the course of the thread. The correct setting of such a thread clamp is relatively tricky.

The clamping force with which the clamping jaws are pressed against one another depends on the nature of the Weft thread and selected differently according to the entry speed, on the one hand to ensure a secure hold

to ensure none or of the thread in the clamp (^ as few as possible

Thread looser) without damaging the thread caught between the jaws. Even those with the help of Thread brakes and thread tensioners kept approximately constant during and between the successive weft insertions The thread tension depends on the thread quality and the strength of the thread Carrying speed different / adjusted so as not to stress the thread unnecessarily, but still use it during to keep evenly stretched in all phases of the weaving process.

In practice it has now been shown that on individual Elements of the known thread clamping devices, in particular on the clamp arms, the clamping jaws and the springs, Vibration phenomena occur during operation. These are partly due to the rapid, the Clamp opener controlled opening and closing of the clamps,

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part? by the movements of the carrier body (the thread feeder arm or the shooter's body), partly due to other external influences effective during the weft insertion (e. B. the shuttle guide when passing through the shed). Such vibrations impair the functional reliability the thread clamp by prying them together cause or at least promote chafing of the clamping jaws. To provide sufficient security against To ensure thread losers, it is therefore necessary to reduce the clamping force with which the jaws are pressed against one another, to be set relatively strong, for example for medium yarns and insertion speeds of approx. 15 to 20 m / s in the order of 2.2 kg and more. This is more than would be necessary to hold the thread in place, if vibrations of the clamp did not have to be taken into account.

The present invention aims to improve the operation of the thread clamp by eliminating the vibrations mentioned above the clamp arms and jaws are prevented or at least strongly damped.

The invention consists in that the clamping device has at least one stop body with stop surfaces, on which the two clamp arms come to rest with a partial amount of the spring force when the clamp is closed.

The stop body can be made from a material that is not particularly flexible per se, such as wood or metal, preferably but at least partially made of an elastic and dampening flexible material, for example rubber or plastic, be made.

Appropriate setting of the support pressure

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kes of the clamp arms on the stop surfaces and the choice of for the latter material used as well as by a suitable one The shape of the stop body, the clamp arms and the springs can, as experience shows, the occurrence of Vibration of the clamp arms, springs and jaws far ~ to be avoided.

The spring force acting on the clamping jaws can be this arrangement without compromising security against Thread losers, with otherwise the same conditions as compared to the known clamping devices, noticeably in certain cases up to a third. Because the clamping jaws collide less hard and when closed also no longer rub against each other, the thread end clamped in between is treated more gently and lasts longer the clamping device is increased accordingly.

Conversely, the inventive design of the thread clamping device offers the possibility of using the same the jaws acting clamping force a greater operational reliability of the weft thread insertion than with the known designs to achieve, d. H. the clamping device for looms with larger weaving widths and / or for greater insertion speeds or accelerations than without vibration damping Use stops.

The invention can be applied to various known embodiments of the clamp arms, stop bodies and realizing feathers. So is preferred for the thread feeder an embodiment is used in which the spring-loaded clamp arms are rigid and the jaws are attached to them remote end are articulated to the support body.

This form of thread clamp has the advantage of

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relatively strong, stable construction in which the Jaws are guided exactly parallel to each other in every position and cannot twist each other, even if the

Axis of symmetry

The thread does not ^{lie exactly in the 7 of} the clamping jaws.

In contrast, an embodiment in which .die Klammerarmeselber designed as pretensioned spring legs and are firmly connected to the carrier body at their end facing away from the clamping jaws. The)

both clamp arms can then consist of one piece, d. H. at their end facing away from the clamping jaws connected to one another in a U-shape by a yoke, which is attached to the support body, for example, is riveted to him. This type of clamp is particularly simple and light, and insensitive to Shocks and vibrations from external influences.

In a preferred embodiment of the invention, the stop body is on the support body of the thread clamping device attached. The stop body causes a certain guidance and centering of the thread clamp, so that the spatial position of the clamping jaws is clearly defined in their closed state relative to the carrier body. As a result, it is no longer necessary, for example, with a thread feeder, as is the case for the known constructions of The case is to make the two clamp arms differently strong, if necessary, to pretension them unequally and the stronger one equip the loaded arm with a fixed stop. the

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On the contrary, the bracket can be arranged completely symmetrically, what a considerable simplification of the storage of the individual parts and the adjustment of the finished bracket to achieve allowed. By centering the closed clamp, a perfect transfer of the thread, for example from feeder to shooter clamp ensured.

In the case of a grab guard with a stop body attached to the carrier body and arranged between two clamp arms it is sufficient to fasten the clamp with a single rivet instead of the two rivets previously required in the shooter body, because the clamp is closed in the shooter body State automatically through the cushioning stops in their central position centered. With the length of the shooter body unchanged longer clamp springs can be provided than in the known designs, and with the same clamping force the risk of fatigue fractures of the springs is noticeably reduced.

In certain cases, for example, when the support body is not up to the height for some reason the clamping jaw is preferred, or the attachment of the stop body for structural reasons not on the carrier body may be provided, the stop body can be attached to a clamp arm.

Instead of the one, arranged between the clamp arms In a further embodiment, stop bodies can have two stop bodies attached outside of operating levers, be provided on which the actuating levers come to rest when the clamp is closed.

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The resilience of the stop surfaces on which the clamp arms are attached to the stop body when the clamp is closed are applied, is advantageously, depending on the yarn quality to be inserted and the intended insertion speed (or thread acceleration), dimensioned differently. For example, when converting a loom to other operating conditions or a different thread quality, including the thread feeder and the protection against such are exchanged, the thread clamps and stopper body experience has shown for the present in the subsequent weaving process Conditions are considered particularly suitable.

In further embodiments of the invention Thread clamping device is the distance between the two clamp arms belonging to the two clamp arms, i. H. simultaneously effective stop surfaces on the stop body adjustable. The clamping device can also be used to hold stop bodies be set up, the different distances between the belonging to the two bracket arms

Have stop surfaces and rotatable, or against each other

measured in the longitudinal direction of the bracket

are interchangeable. Finally, the / distance between the stop body and jaws be adjustable. This is

effective
it is possible to change the length of the lever arm with which the clamp arms are pressed onto the bearing surfaces. This has practically the same effect as changing the flexibility of a stop body permanently mounted on the support body.

Structure and mode of operation of the thread clamping device according to the invention are based on the drawings and the

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The following description of various exemplary embodiments is explained in more detail.

Show it:

1 shows an embodiment of the clamping device,

as used in thread feeders

two
is used with / rigid clamp arms,

with the thread clamp closed,

2 shows a top view of the thread clamp according to FIG. 1, partly in section, according to II - II in FIG. 1,

3 shows a view of the thread clamp according to FIG. 1, with the clamp open,

4 shows a section of the thread clamp according to IV - IV in FIG. 3, to illustrate the mode of operation of the clamp opener,

5 shows a view of a gripper guard with a thread clamping device according to the invention, in which the clamp arms are designed as spring legs,

6 shows a plan view of the shooter, partly in section, according to VI - VI in FIG. 5,

Flg. 7 shows a view of the cylindrical stop body having the damping stops according to Fig. 5,

8 shows a partial section through a gripper guard similar to FIG. 5, but with a different one Embodiment of the stop body, the attached to a bracket arm

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FIG. 9 shows a detail from a section through a gripper guard similar to FIG. 6, however with a stop body with adjustable flexibility, according to IX - IX in Fig. 10, 10 shows a view according to X-X belonging to FIG. 9,

similar to a section of Fig. 1,

11 and 12 show two representations corresponding to FIGS. 1 and A _1, but with an axially adjustable stop body, omitting the parts unchanged from FIGS. 3 and 4, FIGS. 13 and 14 show a section and a view corresponding to FIGS. 9 and 10, but with a stop body of hexagonal cross-section, and

15 shows a schematic representation of a stop body with an oval cross-section, e.g. B. for grab shooters.

In Fig. 1 to 4, 1 denotes the carrier body of a weft thread feeder, which has the shape of a profile rail, which as a whole in a manner known per se for grasping and guiding the weft thread 2 or weft thread end in the direction of the arrow 3 can be moved back and forth. The jaws 4 are located at the free ends of the rigid clamp arms 5, which at their ends facing away from the clamping jaws are articulated to the support body 1 by hinge pins 6 are. The clamp arms 5 are above the hinge pins 6 surrounding bores are also extended by actuating lever 7, into which at the point where a fork is

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ger opener 9 at its according to arrow 10 transversely to the plane of the Carrier body 1 executed movement on the actuating lever 7 strikes in order to open the clamp, a hard metal plate 8 is embedded. Two spring legs 11 which are rigidly attached to the support body 1 at one end by rivets 12 are attached, exercise with their free ends on the operating lever 7 an outwardly directed spring force in the Meaning that the operating lever 7 spread apart, d. H. the jaws 4 are pressed against each other as long as the opener 9 is in its rear rest position without engagement with the actuating levers 7. If the opener 9 pushed forward into its working position, so meet the wedge-shaped converging inner surfaces 1 3 of the fork-shaped Openers 9 on the hard metal plate 8 of the actuating lever 7 and press them together. The clamp arms 5 pivoted about its hinge pin 6 and the clamp opens until the actuating lever 7 rests on the limit stop 14.

Between the clamps 5 is in the support body 1 a stop body 15 attached, for example riveted. It consists of a solid material such as wood or metal or preferably at least partially of an elastic material and damping resilient material, such as rubber or a plastic such as nylon, Teflon, or the like and has damping stop surfaces 16 on which the spring-loaded Clamp arms 5 with the clamp closed with a partial amount • the spring force acting on it rest, while the remaining Spring force serves to press the clamping jaws 4 against one another, d. H. to grasp the thread 2 with the clamp.

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The pressing force with which the clamping jaws A are pressed against one another can be freely selected or adjusted within wide limits on the basis of empirical values and depends on the properties of the thread 2 used, its diameter, weight, strength, elasticity, etc. initially described embodiment by the shape and the setting (z. B. by subsequent cold deformation) of the spring legs 11, and determined by the position, the shape and the flexibility of the stop body 15. If necessary, the stop body 15 is compressed by the clamp arms 5 by an amount χ due to its resilience when the clamp is closed on the stop surfaces 16. When the clamp is opened, the stop body, because of its elasticity, also resumes its original, for example cylindrical, shape in this case. When the clamp is open, there is no longer any contact between the clamp arm 5 and the cushioning support surface 16.

Shape and mass of the clamp arms 5, the actuating lever 7, 8 and the spring legs 11 and the bias of the the latter influence the type of vibrations that experience has shown in operation without the stop body 15 on the individual Elements would occur when the clamp is actuated by the opener 9 or as a result of other external influences. the Dimensions, shape and mechanical properties of the Stop body and the clamp arms determine the effectiveness, in particular the damping capacity of the inventive Clamping device.

In Fig. 1 is a variant with 15a indicated for the stop body 15, in which instead of the one,

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between the clamp arms 5 arranged body on the two transverse webs 1a, b of the support body 1 each one optionally elastically and damping resilient stop body 15a is installed, on which one of the actuating levers when the clamp is closed 7 is present.

The thread feeder shown in Fig. 1 to 4, or its thread clamping device is with respect to the course of the The thread is completely symmetrical. For the perfect transfer of the thread end: From the feeder to the shuttle clamp it is important that the clamping jaws 4 are in the closed state, i. H. with the thread end held by them, im Moment of handover in a precisely defined position in are in the immediate vicinity of the open contactor clamp. This is achieved with a practically play-free, precise guidance of the Carrier body 1 in the weft device of the loom achieved by the freely pivotable about their pivot pins 6, clamp arms 5 under spring tension close around the stop body 15 and on both sides of it Stop surfaces 16 are in contact. The stop body thus centers the closed clamp and thereby holds it together the thread end held by it in relation to the support body 1 and thus to the Grelferschützen clamp exactly in the desired Fixed position. .

Another embodiment of the invention Thread clamping device as used, for example, in the gripper guards of weaving machines, in which the Weft supply bobbin during the weft insertion outside

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half of the shed remains, is shown in Figs. The support body used here is the sleeve 21 of a one-part or multi-part Contactor body of the usual type. The shooter body has front, d. H. in the direction of fire, a massive one

Head and back an opening 23 through which the thread clamp 24, 25, 31 is inserted and built into the shooter, so that the clamping jaws 24 are accessible but protected against external influences in the area of a slot-shaped recess 27 are arranged at the rear end of the shooter body sleeve. The clamp arms 25 are pretensioned spring legs educated. At the level of the bores 26 in the side wall of the sleeve, the clamp arms 25 are thickened or hard metal plate .28 reinforced, between which the clamp opener 29 is executed in the direction of arrow 30 Forward and backward movement with its wedge-shaped cutting edge 33 is pressed to the arms 25 and thus the Spreading jaws 24 apart, d. H. to open the clamp. The two spring legs 25 can by a Yoke 31 connected to one another and made in one piece. The yoke 31 is attached to the carrier body (the sleeve 21), for example with the help of a rivet 32. In a further bore 34 with a stepped diameter is a substantially cylindrical, solid or, if necessary, elastic and damping yielding stop body 35 (FIG. 7) is pressed in or riveted, which each forms a damping stop surface 36 for the spring arms 25, which when closed Bracket can be pressed in by the amount χ if the surface 16 has been designed to be flexible. Centered here too the stop body 35

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the bracket with respect to the axis of symmetry of the protector, so that a single rivet 32 is used to secure the bracket in the shooter body is sufficient. With such a design, it is possible to use longer ones with the same overall length of the shooter To install spring legs 25 in the shooter than with the previous usual forms in which the yoke 31 of the clamp with two rivets arranged one behind the other on the shooter body is attached.

The stop body is in the two previously described embodiments on the carrier body on any Way attached, e.g. B. riveted, screwed in, pressed in or glued. If a separable connection is provided, this allows a certain adjustability of the damping properties to adapt to the requirements of different types of threads or yarns can be achieved by e.g. B. interchangeable stop bodies 15, 35 are provided, the different Have distances ("width across flats") between their opposing stop surfaces 16.

Instead of being a cylinder with a round cross-section, the stop body can also be cube-shaped 37 (FIG. 8) or in its In the longitudinal direction, because of its spacer sleeve 41b, hexagon 35b (Fig. 13), octagon, etc. may not be compressible. Advantageously, bodies with slightly (by a few tenths of a millimeter) different "wrench sizes" 39a, 39b, 39c between two opposite, d. H. simultaneously

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away

effective stop surfaces are used, so that if necessary the body to adapt the damping properties to a other "wrench size" 39a, 39b, 39c can be used rotated. Continuous adjustability can be achieved by a stop body 35c, FIG. 15 with a slightly oval cross-section, rotatable about its axis according to arrow 46 and detectable, is inserted into the support body 1.

In FIGS. 9 and 10, a resilient stop body 35a, in contrast to 35b in FIG. 13, is of cylindrical design and compressible in its longitudinal direction by means of a pressure plate 41 and a countersunk screw 42, so that its Diameter 39 and his. Resilience to the clamp arms 5 in certain, corresponding to the desired purpose Limits is adjustable.

In the embodiment according to FIGS. 11, 12, the stop body consists of a solid, metallic block 43, and is optionally equipped with stop buffers 44 that are resilient and resilient in a damping manner. The block 43 is guided by appropriately designed guide edges in a longitudinal slot 45 of the support body 1 and in the longitudinal direction adjustable by means of a screw 42a clamped with a washer. In this way the distance 4 0 between the clamping jaws 4 and the stop body 43, 44, d. H. the length of the effective lever arm on the clamp arms for the stop, can be adjusted as required.

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Claims (10)

- 17 - T.365 Claims j Thread clamping device, consisting of a carrier body, a thread clamp attached to it, which can be closed by spring force and which has two clamping jaws attached to the free ends of clamp arms, and an opener for temporarily spreading the clamping jaws apart, characterized in that the clamping device has at least one stop body (15, 15a, 35, 35a, 3 5b, 35c, 37 or 43, 44) with stop surfaces (16, 36, 38, 44) on which, when the clamp is closed, the two clamp arms (5, 25) with a partial amount of the spring force to rest come. 2. Thread clamping device according to claim 1, characterized in that the spring-loaded clamp arms (5) rigid and at their end facing away from the clamping jaws (4) are articulated to the carrier body (4). 3. Thread clamping device according to claim 1, characterized in that the clamp arms (25) themselves are pretensioned Spring legs formed and at their end facing away from the clamping jaws (24) fixed to the carrier body (21) are connected. -18- 10988 5/1079 4. Thread clamping device according to claim 3, characterized in that the two Klammer.arme (25) from one Piece. 5. Thread clamping device according to claim 1, characterized in that the stop body (15, 35) on the carrier body (1, 21) is attached. 6. Thread clamping device according to claim 1, characterized in that the stop body (37) on a clamp arm (25) is attached. 7. Thread clamping device according to claim 1, characterized in that it is for receiving stop bodies (15,35) is set up, the different distances (39, or 39a, b, c) between two stop surfaces (16, 36) have, on which the two clamp arms can be supported at the same time, the stop bodies (15, 35) being rotatable or rotatable. are interchangeable. 8. Thread clamping device according to claim 1, characterized in that the distance (40) between the stop body (43,44) and clamping jaws (4) is adjustable. 9. thread clamping device according to claim 1, characterized 109885/1079 characterized in that the stop body is at least partially made of an elastically and dampening flexible material is made. . 10. Thread clamping device according to claim 1, characterized characterizedy that the distance (39) between the two increases the stop surfaces (16, 36) belonging to the clamp arms on the stop body (15, 35, 35a) can be adjusted. 109885/10 79