TW201402894A - Drafting arrangement for drawing a roving yarn - Google Patents

Abstract

The invention relates to a drafting arrangement for drawing a roving yarn with drafting fields formed by feed, centre and withdrawal roller pairs and a connected compression zone, wherein top delivery rollers are connected by means of a cage element to the top withdrawal rollers and the cage element is loaded in the direction of bottom delivery rollers by means of a loading spring, which is configured as a leaf spring. According to the invention it is provided that the cage element (25) has a first guide and receiving device (29), the inside diameter of which is slightly above the diameter of an axle (13) of the top withdrawal roller pair (4o), on which the cage element (25) is mounted and in that the loading spring (15) is stationarily connected by one end to the oscillating carrier (5) and is movably connected in the region of its opposing free end (14) by an intermediate member (16, 17, 18) to the cage element (25) receiving the top delivery rollers (110).

Description

Traction device for pulling woollen yarn

The present invention relates to a drafting device for drawing a spun yarn according to the first paragraph of the patent application.

Drafting devices for drawing woollen yarns are common in the textile industry and are used on different textile machines. For example, a station of a ring spinning machine is equipped with a drafting device of the type that draws a roving of a flyer bobbin to form a fiber ribbon of high fineness, the fiber The belt is then twisted and wound onto a spinning cop as a finished yarn.

This type of drafting device typically has three bottom rollers that are spaced apart along the length of the machine and that are driven at different rotational speeds by a drive disposed at the end of the machine, and are disposed in a pivotally assembled oscillator carrier. The top three are associated with the top roller. During the spinning operation, the top drum rests on the driven bottom drum with a predetermined contact pressure and is driven by the frictional engagement by the driven bottom drums. In other words, the top drum and the associated bottom drum form a pair of rollers that ensure that the fed yarn is drawn as it passes through the drafting device due to its different rotational speeds.

As indicated above, this type of drafting device typically has a pair of feed rollers, a pair of central rollers and a pair of extraction rollers, the region of the pair of rollers and the center roller forming a so-called pre-drafting field, The area between the center roller pair and the pair of extraction cylinders serves as the main drafting field.

The fed roving yarn is drawn to the desired fineness in the drafting device and exits the drafting device at the gripping line of the extraction drum pair as a relatively wide fiber band that is drawn up to, for example, 50 times. As indicated above, a spinning twist is then applied to the relatively wide fiber band by rotating the worsted bobbin in conjunction with the associated traveler of the associated workstation, and twisting is performed during the process to form the finished yarn. In practice, this means that after the drawing of the pair of rollers, a so-called spinning triangle is formed in which the fiber strips leaving the drafting device are placed together and twisted to form a yarn structure. In general, because the width of the drawn fiber ribbon significantly exceeds the diameter of the finished yarn, not all fibers are incorporated or improperly incorporated into the yarn structure in the worsted triangle, and the finished product is the edge fiber and the finished product. The yarn is prominent.

In order to avoid the appearance of such edge fibers as much as possible, it has been proposed in the past to incorporate a ring spinning machine to supplement the drafting devices of such textile machines by means of so-called compression zones. In other words, the pair of delivery rollers are coupled to the pair of extraction cylinders, the top delivery roller pair being rotated, for example, by the associated bottom delivery roller by frictional engagement. In an alternate embodiment, a common bottom drum can also be provided that is both subjected to the top extraction drum and the top delivery drum, or uses a top driven drum driven transmission or a drag component drive to drive the top delivery drum. A special compression device that can be configured, for example, as a mechanical compressor or pneumatically operated, is also disposed between the pair of extraction rollers and the pair of delivery rollers.

The top extraction drum disposed in front of the compression zone and the top delivery drum disposed above the compression zone are typically assembled in a common cage element such that the roller pairs are guided parallel to one another. In other words, the saddle of the cage element transversely adjacent the axle of the top extraction drum engages the first axle guiding means of the cage element throughout the axle, which in turn is arranged in a so-called delivery connection of the oscillating carrier In the rod, it is held by a saddle spring. The extraction tie rods are typically loaded by spring elements in such a manner that the top extraction drum rests on the associated bottom extraction drum with a defined contact pressure. During the spinning operation, the top delivery roller must also rest on the bottom delivery roller with a specific load force, as this is only possible in this way. The compressed fibers are also properly transported in the region of the compression zone. Various methods and devices for generating this load force are known to us, and this load force is absolutely necessary for proper operation of the compression zone.

By way of example, it is known in practice to provide a cage element having a molded surface that is configured and configured such that the cage element is supported in the mounted state and below the delivery link when the oscillating carrier is closed on. In other words, the load force introduced by the extraction connecting rod is transmitted to the cage member by the molding surface, and is distributed throughout the top extraction drum and the top delivery roller according to the respective intervals.

A disadvantage of this known type of connection of the top delivery roller is in particular the fact that the top extraction cylinder is generally lifted slightly from its guiding and accommodating means in the cage element, causing the top extraction cylinder to no longer be accurately guided. This situation basically causes the yarn quality to deteriorate.

Modification of known drafting devices (for example, a significant increase in the maximum load force by extraction of the connecting rod) does not provide any permanent achievement, since this significant increase in the type of load force not only results in a settling effect at the top drum. (This situation also weakens the achievable yarn quality) and also makes the defined adjustment of the optimum load force of the top drum much more difficult.

In order to eliminate the problem of reduced guiding of the top extraction cylinder in the cage element, it has been proposed in the past to additionally load the cage element by means of an additional leaf spring. An additional slab spring of this type can be fastened to the oscillating carrier of the drafting device, for example by means of a screw connection, as described, for example, in DE 100 05 387 A1, or as DE 10 2009 050 581 Known by A1, it is statically arranged on the cage element.

However, it has been found in practice that such known devices are also extremely disadvantageous when the bottom delivery roller (the top delivery roller rests on the bottom delivery roller during the spinning operation) does not have precise concentricity. In the case of such a situation, the cage element (the top delivery roller is assembled in the cage element) performs a pivotal movement about the top extraction drum, causing the leaf spring and the cage when the load spring is fastened to the oscillating carrier. The fact that relative movement occurs between shaped elements. Here the friction occurring between the leaf spring and the cage element results in a reverse torque which is in the cage element The downward load causes the load force existing in each condition to be weak, and in the case of the upward movement of the cage element, the load force existing in each condition is enhanced. In other words, in such known devices, the load force to be applied by the top delivery roller during the spinning process is not constant, but varies, when the bottom delivery roller does not have precise concentricity, which greatly impairs yarn quality.

Proceeding from the foregoing prior art, the present invention is based on the development of a drafting device for drawing a spun yarn in such a way that a constant load force can always be ensured during the spinning operation, even in the compression zone. The same is true for the top delivery roller.

This object is achieved according to the invention by a drafting device having the features described in claim 1 of the patent application.

Advantageous configurations of the invention are the subject matter of the scope of the appended claims.

According to the configuration of the present invention (wherein the cage member has a first guiding and accommodating device, the inner diameter of the first guiding and accommodating device is slightly higher than the diameter of the wheel shaft of the pair of extraction rollers, and the cage member is fitted in the axle And wherein the load spring is statically coupled to the oscillating carrier of the drafting device by one end and is connected to the top delivery roller or the cage of the top delivery roller by means of a movable intermediate member in the region of its opposite free end The shaped element) has the advantage that the abutment which is influenced by the friction of the load spring on the cage element can be substantially prevented, and thus the load spring can be ensured by means of the movable intermediate member, which is actually loaded without friction. The force is transmitted to the top delivery roller or cage element and thus also to the top delivery roller. Also by the first guiding and receiving means arranged in the cage element (the inner diameter of the guiding and receiving means is slightly higher than the diameter of the axle, the cage element is mounted on the axle, the cage element thus having a slight play In this case, it rests on its associated load-bearing axle) and ensures that the cage element can pivot virtually without force around its load-bearing axle. In other words, in the case of the configuration according to the invention, it is reliably avoided that the cage element (as is known in the prior art) is fastened to the axle of the top extraction cylinder pair by means of the receiving device, the receiving device having Unfavorable clamping mechanism. As known, clamping engagement A storage device of this type that operates has the disadvantage that, particularly in the case of non-concentric operation of the bottom delivery roller, the torque is always opposite the forced up and down movement of the cage element, which is comparable to such up and down movements. And as a result, the load force of the top delivery roller is unduly fluctuating.

In the preferred configuration, it is provided that the intermediate member is configured as a rolling body that is movably mounted in the guiding device of the cage element. This type of movably assembled rolling element loaded by a load spring not only works extremely reliably during the spinning operation, but is also an economical component with a long service life.

According to the third aspect of the patent application, it is further provided that the load spring is configured as a leaf spring which is bent in an L shape, the first leg of the leaf spring being stationaryly fixed to the oscillating carrier, and the leaf spring The second free leg rests on the movable intermediate member. The load spring configured in this way can be reliably fixed on the one hand in a predeterminable mounting position and on the other hand can be easily positioned such that a virtually frictionless transmission of the load force is provided.

As described in claim 4, in an alternative embodiment, it may also be provided that the movable intermediate member loaded by the load spring is formed by the axle of the top delivery drum, which is free in situations such as this. Rotatingly mounted in the second guiding and receiving device of the cage member. This type of configuration has, for example, the advantage that the load spring is directly applied to the saddle of the axle of the top delivery roller pair; the load force therefore does not have to first be bypassed via the cage element. Due to the freely rotatable assembly of the top delivery roller pair of axles in the cage element, it is also reliably ensured here that the load force of the leaf spring is transmitted to the top delivery roller without any delay.

It is also provided in an advantageous embodiment that the guiding and receiving means for the arrangement of the top delivery roller pair of the cage element in the cage element are configured as a fork guide, the fork guide The longitudinal direction is substantially tangent to the circular path, and the top delivery roller performs the circular path around the top extraction drum during up and down movement. This type of configuration means that the cage element can be pivoted precisely to the axle of the top extraction drum pair. This behavior is also achieved by the top delivery roller Contributed to a known suspension of its associated bottom delivery roller.

As described in claim 6 of the patent application, when the axle of the top delivery roller is loaded by a leaf spring that is curved in an L shape, a particularly advantageous embodiment is also provided, the panel resting on the axle of the top delivery roller. The free leg of the leaf spring is bent twice again. This type of configuration is a compact and functionally reliable construction that is also readily available when necessary, which also ensures a perfect migration of the required load force.

In a further specific example described in claim 7 of the patent application, it is provided that the movable intermediate member is configured as a connecting rod. The connecting rod is here rounded in the region of its two end faces and is movably mounted to a limited extent by the load spring and erected in the recess of the cage element. This type of connecting rod, rounded at both ends, allows for virtually no hysteresis transmission of the constant load force preferably provided by the leaf spring.

The invention will be described in more detail below with reference to specific examples shown in the drawings, in which: Figure 1 shows a drafting of a towed spun yarn according to a first configuration of the invention having a compression zone Figure 2 shows a drafting device having a second embodiment of a compression zone; Figure 3 shows a drafting device having a third embodiment of a compression zone.

As is known, the drafting device 1 shown in Fig. 1 has a pair of feed rollers 2, a pair of central rollers 3 and a pair of extraction rollers 4. The drum pairs 2, 3, 4 are formed in each case by a bottom drum and associated top drum. The bottom drum, which is usually driven along the length of the machine and, for example, driven by the drive and the corresponding transmission at the end of the machine at different rotational speeds, is attached to the ring-shaped fine by means of a punch (not shown). On the machine frame of the textile machine, the top roller driven by the bottom roller by the frictional engagement during the spinning operation is in each case by a so-called connecting rod Connected to the oscillating carrier 5, the oscillating carrier 5 is fixed to the holding rod 12 by means of a support member 28, and the holding rod 12 is fastened to the machine frame. The oscillating carrier 5 can be positioned at the position "drawing device folding" or "drawing device loading" by means of the operating lever 6, and the third position "drafting device unloading" is placed on the bottom roller on the top roller and the operating lever 6 is not Adjusted when in its closed position.

The drafting device 1 of this type between the pair of feed rollers 2 and the pair of extraction cylinders 4 has a drafting zone 30 in which the fed rovings 26 are preferably drawn up to 50 times their feed length. The drafting zone 30 is in this case divided into a pre-draft field 7 between the pair of feed rollers 2 and the pair of central rollers 3, and a main drafting field 8 between the pair of central rollers 3 and the pair of extraction cylinders 4. A compression zone 10 between the pair of extraction rollers 4 and the pair of delivery rollers 11 is adjacent to the drafting zone 30. As can be seen from Figure 1, the top extraction roller pair 4o is coupled to the oscillating carrier 5 by a spring loaded extraction link 9; in other words, the wheel 10 of the extraction delivery roller pair 4o is fixed to the extraction connection by its saddle member. In the receptacle of the rod 9, it is preferably fastened by a spring element.

Immediately next to the saddle of the axle 13, the cage element 25 is configured with a first guiding and receiving means 29 with play. The cage element 25 spaced apart from the first guide and receiving means 29 for the axle 12 of the top extraction cylinder pair 4o also has a second guiding and receiving means 31 for the axle 17 of the top delivery roller pair 11o, and A guiding device 19 for the movable intermediate member 16. The intermediate member 16 which is displaceably mounted in the cage element 25 in the guiding device 19 is configured as a rolling body and, in the assembled state, is loaded by the free leg 21 of the load spring 15 configured in an L-shape. The load spring 15 is stationaryally fastened to the oscillating carrier 5 of the drafting device 1 by its second leg 20 . This means that there is no static friction of any kind between the free leg 21 of the load spring 15 and the cage element 25 carrying the top delivery roller pair 11o, so that there is virtually no hysteresis of the predetermined load force by means of the load spring 15. The transfer is ensured onto the cage element 25 and is therefore ensured to the top delivery roller pair 11o, even in the case of non-concentric operation of the bottom delivery roller pair 11u.

Figure 2 shows the drafting zone 10 arranged on the oscillating carrier 5 of the drafting device 1 The second specific example. It can be seen that the cage element 25 spaced apart from the first guiding and receiving means 29 also has a second guiding and receiving means 31 for the axle 17 of the top delivery roller pair 11o, the cage element 25 being in this specific example It is also supported on the axle 13 of the top extraction roller pair 4o by the first guiding and receiving means 29. As in the first embodiment, the inner diameter of the first guiding and receiving means 29 is here also higher than the diameter of the axle 13.

In the present embodiment, the axle 17 acts as a movable intermediate member and, for this reason, is rotatably mounted in the second guiding and receiving means 31 of the cage member 25. In other words, the freely rotatably assembled axle 17 is loaded by the free leg 21 of the L-shaped load spring 15, and the free leg 21 is preferably bent twice. The load spring 15 is here also fixed stationary to the oscillating carrier 5 of the drafting device 1 by its second leg 20 .

The rotatable assembly of the top delivery roller pair 11o as the intermediate member axle 17 here also allows for a predetermined load-free force by the load spring 15 to the almost no hysteresis transmission of the top delivery roller pair 11o, the respective effective load forces actually Independent of the concentric running nature of the bottom delivery roller pair 11u.

In a further embodiment shown in FIG. 3, the intermediate member loaded by the load spring 15 is configured as a connecting rod 18. The connecting rod 18 has a radius 23 or 24 on the end face in each case and is movably fitted in the recess 27 of the cage element 25 to a limited extent. The connecting rod 18 is also loaded by the free leg 21 of the L-shaped load spring 15, and the L-shaped load spring 15 is stationaryly fixed to the oscillating carrier 5 by its second leg 20, which is similar to that described above. The situation in the specific example.

The movable configuration of the connecting rod 18 acting as an intermediate member also reliably prevents static friction from occurring in conjunction with the operation of the load spring 15, particularly in the case of non-concentric operation of the bottom delivery drum 11u.

Claims (7)

A drafting device for pulling a roving yarn having a drafting field formed by a pair of feeding rollers, a pair of central rollers and a pair of extraction cylinders, and a connected compression zone, wherein the top delivery roller is supported by a cage element And connected to the top extraction drums, and the cage elements are loaded in the direction of the bottom delivery drum by means of a load spring configured as a leaf spring, the drafting device being characterized by: The cage element (25) has a first guiding and receiving device (29), the inner diameter of the first guiding and receiving device (29) is slightly higher than one of the top extraction roller pairs (4o) (13) The cage element (25) is mounted on the axle (13); and the load spring (15) is statically connected to the oscillating carrier (5) by one end and at its opposite free end ( The region of 14) is movably coupled to the cage member (25) that houses the top delivery rollers (11o) by an intermediate member (16, 17, 18). A drafting device according to claim 1 is characterized in that the intermediate member is configured as a rolling body (16), the rolling body (16) being movably mounted to one of the cage members (25) Guide device (19). A drafting device according to claim 1, characterized in that the load spring (15) is configured to bend a leaf spring in an L shape, the first leg of the leaf spring (20) Statically fixed to the oscillating carrier (5), and the second free leg (21) of the leaf spring rests on the intermediate member (16, 17, 18). A drafting device according to claim 1, characterized in that the intermediate member loaded by the load spring (15) is formed by an axle (17) of one of the top delivery rollers (11o), the axle ( 17) rotatably mounted in one of the guiding and receiving means (31) of the cage member (25). The drafting device of claim 4, wherein the guiding and accommodating device (31) is configured as a fork guide, the longitudinal direction of the fork guide is tangent to a circle Shape path, The top delivery roller (11o) performs the circular path around the top extraction drum (4o) during up and down movement, and the circular path allows the axle (17) of the top delivery rollers (11o) to be in the fork shape One of the guides moves. A drafting device according to claim 4, characterized in that the axle (17) of the top delivery roller (11o) is loaded by a load spring (15) bent in an L shape, resting on the The free leg (21) of the load spring (15) on the axle (17) of the top delivery roller (11o) is again bent twice. A drafting device according to claim 1, characterized in that the intermediate member is configured as a connecting rod (18) which is rounded on its two end faces (23, 24) and Loaded by the load spring (15), the connecting rod (18) is movably fitted to a recess (27) of one of the cage elements (25) to a limited extent.