DEVICE AND METHOD FOR AUTOMATICALLY CONNECTING THE YARN TO THE TUBE OF A WINDING MACHINE

Abstract: A device and method for automatically connecting the yarn to the tube of a winding machine, comprising yarn manipulation members (91, 97) grouped on a single arm (90) which rotates in two mutually orthogonal planes, the member for initiating tube rotation consisting of a belt (102) which runs between two pulleys (103, 104). The yarn is connected while keeping the already formed bobbin in a waiting position until yarn connection is completed.

Description: This invention relates to a device for automatically connecting a yarn to a new empty tube in a winding machine. Winding machines are known to consist of a plurality of winding heads, each of which automatically performs the winding operation, which in its essential lines consists of withdrawing the yarn from supply packages, eliminating its defects and then winding it onto tubes to form bobbins of a predetermined size. When the bobbin under formation reaches the required size, the winding head is halted, the bobbin is discharged and must be replaced by a new tube on which a new bobbin is to be formed. As winding machines consist of a large number of winding heads, for example an average of 48-60 heads in straight-line winding machines, it is advantageous for this operation to be performed automatically as a large number of positions may need to undergo the replacement operation within a short time period. This operation is commonly known as doffing, and consists of releasing and discharging the full bobbin, and replacing it with a new tube. A device and method for automatically doffing bobbins in winding machines forms the subject of the copending European patent application No. 88200231.4 of the Applicants claiming the same priority date as the present Application. A device for automatically connecting a yarn to a new empty tube in a winding machine, having means for seizing the yarn to be connected, means for positioning the yarn on the new tube and yarn cutting means, is known from FR-A-2 552 745. According to this known device, which is complicate in structure and function, the yarn coming from a feeding source and extending to a bobbin on which it is wound is first of all seized in an intermediate point and is brought in front of a suction hole. The yarn is than sectioned by cutting means and its end coming from the feeding source is retained in said suction hole, whereas its other end is wound on the bobbin. Manipulation means bring the yarn coming from the feeding source into engagement with a recess formed in an end flange of the empty tube, where the yarn is clamped during rotation of the tube by means of the drive roller. The yarn end going to the suction hole is finally sectioned on the periphery of said tube end flange and is sucked in said hole. This known device does not provide directly to transfer the yarn from the full bobbin to an empty tube, but it requires retaining the yarn end by suction means. Further, the known device requires the use of special tubes equipped with an end flange having at least one recess and a relative yarn clamping member. To manipulate the yarn, besides a manipulation member able to rotate in two planes, a yarn extension member and separate yarn cutting means are used. The purpose of the present invention is to provide a device for directly transferring the yarn from a full bobbin to an empty tube utilizing a more simple yarn manipulation member. This purpose is achieved by a device with the combination of features as defined in the characterising portion of claim 1. From US-A-4 141 513 a chuck accelerating device is known in order to bring the chuck to a peripheral velocity substantially equal to the peripheral velocity of a drive roll, so as to avoid destruction of the bobbin on the accelerated chuck by friction. This chuck accelerating device is not used for driving an ampty tube in order to wind initial yarn turns on it. Preferred embodiments of the invention are defined in subclaims 2 to 4. The invention is described in detail hereinafter with reference to the figures, of which: Figure 1 shows the discharge of a full bobbin; Figure 2 is an overall view of the device according to the invention; Figure 3 shows the yarn cutting member; Figures 4A/B and 5 show winding of the initial yarn turns on the new empty tube. The device according to the invention can be provided either for fixed positioning, or for mobile positioning - which constitutes its preferred embodiment- by supporting the device on one or more mobile carriages which patrol along the winding machine face to serve the winding heads as and when they require this operation. The illustrative figures accompanying the description relate to the device supported on a carriage. In Figure 1, the device is supported by a mobile carriage 1, which is motorised by an electric motor 2 and runs along fixed rails 3 and 4 extending along the machine face. The carriage is driven by the drive wheel 5 connected to the motor 2, and is restrained by idle wheels 6,7 which run along the rails 3 and 4 to exactly determine the position of the carriage 1 in the plane of the figure, in known manner. The carriage 1 can also advantageously act as a support for other winding head service devices, such as for doffing the bobbins or for other operations. One winding head is shown diagrammatically in the figures by means of its more important elements, such as the bobbin drive roller 8 and the bobbin support arm 9. In the most common types of winding machine, the bobbin support arm 9 carries at its ends two holding centres, of which at least one, indicated by 10 in Figure 2, is mobile in an axial direction. These holding centres are made to approach and withdraw from each other to respectively clamp the tube while leaving it free to rotate about its axis, and release it for the doffing and replacement operations. The present invention relates to the connection of the yarn to a new empty tube and has certain implications for the doffing of the full bobbin, from which the yarn to be connected to the new tube has to be seized and retained. The bobbin support arm 9 remains raised - by the action of a member not shown in the figure - during the doffing operation. The full bobbin 11 is released by the mobile holding centre 10 and fixed holding centre, which move apart, and falls onto a mobile chute 13 which is raised to receive it by a piston 36 disposed on the carriage 1. The bobbin then proceeds along a fixed chute 14 towards a conveyor belt 15, which slides along the winding machine to receive the full bobbins. Because of the taper of the bobbins, their correct rolling towards the belt 15 can be assisted by the pivot-mounted levers 40 and 41, the former accompanying and the latter guiding the bobbin. Simultaneously with the raising of the chute 13, the lever 41 moves into the position 41A shown by dashed lines in order to halt the released bobbin 12 along the chute 13 and then guide it gradually towards 15. The levers 40 and 41 are preferably of L-shape and make contact with the bobbin by means of that portion of the L which is perpendicular to the plane of Figure 1. This arrangement allows correct discharge of the bobbin - even for high taper - which guided in this manner does not lie crosswise on the path of the chutes 13 and 14. According to a modified embodiment, the lever 41 can be formed in such a manner as to make a complete anticlockwise revolution about its pivot, so as to firstly retain the bobbin 11 and then accompany it towards the belt 15, this being advantageous if the bobbin has difficulty in proceeding along the chute 14. When the bobbin 11 has been raised from the holding centres, a new tube 12A is fed and loaded onto the bobbin support arm 9. In order to be able to resume winding with the new tube 12A, the yarn originating from the winding head must be seized and controlled during the doffing operation. For this purpose a manipulation arm 90 is used, which is pivoted at C and is able to rotate in two substantially orthogonal planes. During the sliding of the bobbin 11 along the chute 13 the yarn 80 is still connected to the bobbin 11, and forms an angle with the upper edge of the chute 13, which is shaped with a lead-in notch 81 for the yarn, which passes through the position 80A. The arm 90 is provided with a hook-shaped end part 91 constituting a yarn seizing member. Said end part 91 is provided with a cutting member shown in Figure 3. The cutting member consists of a fixed cutter 92 and a mobile cutter 93 which are pivoted together. Said cutting member is opposed by a spring 94 which tends to keep it open, and is operated by a lever 95 controlled by a rotating rod 96 which passes along the body of the arm 90. Said arm 90 is further provided with an L-shaped introduction member 97 able to rotate about the axis 98, substantially parallel to the arm 90. The arm 90 undergoes the sequence of rotations indicated by the arrows in Figure 2: it descends into the position 90A in a substantially vertical plane, then rotates in a plane orthogonal to the preceding to reach the position 90B so that the hook-shaped end 91 collects the yarn in the position 80A and moves it into the position 80B, after which the arm rises in a substantially vertical plane into the position 90C, so dragging the yarn into the position 80C. During this operation the introduction member 97 rotates about its axis 98 to move downwards and urge the yarn 80 in front of the holding centre 10. During this operation the holding centres are free and are not yet occupied by the new tube 12A. The new tube 12A is then positioned, and as its bottom end comes into engagement with the holding centre 10 it clamps the yarn which has previously been moved into the position 80C and grips it when the mobile holding centre 10 closes to lock the bottom end of the tube 12A. When the holding centre 10 has closed, the cutting member disposed at the end part 91 of the arm 90 can be operated. The mobile cutter 93 closes against the fixed cutter 92 to cut the yarn. Of the two yarn tail ends, the end towards the roller 8 is released (it being retained by the holding centre 10) whereas the other end towards the bobbin is retained between the two cutters 92,93 so that it does not interfere with the tube 12A during the yarn connection. The arm 90 remains in the position 90C. A further arm 100 is now lowered, which is pivoted on the carriage 1 by means of a pin D so that it rotates in a plane substantially orthogonal to the axis of the tube 12A. The arm 100 is provided with a motor 101 driving a belt 102 which extends between a drive pulley 103 and a driven pulley 104. The belt 102 driven by the motor 101 is brought by the arm 100 into engagement with the new tube 12A so making it rotate in the direction of the arrow and collect the yarn 80 in the form of initial closely adjacent turns on the bottom end of the tube according to the position of the introduction member 97. The number of turns wound depends upon the time of operation of the motor 101. Driving the tube 12A by means of the belt device is very advantageous in that it can drive the tube for any position of the bobbin support arm 9 - as shown in Figures 4A/B - and its contact is very delicate such that it cannot damage the tube. The yarn has now been connected and winding can be resumed. According to a preferred application of the invention, the full bobbin to be discharged is retained on the discharge chutes 13/14 by the pivot-mounted lever 41, and its yarn end is retained between the two cutters 92/93 until connection has been completed in order to ensure that this yarn end is controlled at all times and does not become entangled in the machine members, with obvious negative consequences. Only when yarn connection is complete is the bobbin 11 delivered to the belt 15 and removed. The manipulation arm 90 moves into the rest position to disengage the introduction member 97. The bobbin support arm 9 can now be returned to engagement with the drive roller 8, and winding is resumed.

Claims: A device for automatically connecting a yarn to a new empty tube in a winding machine, comprising a member for seizing the yarn to be connected, a member for positioning the yarn on the new tube and a yarn cutting member, characterized in that the yarn (80) to be connected to the new empty tube (12A) is seized from a full bobbin (11), released from the holding centres (10) of a bobbin support arm (9) and temporarily retained on a discharge chute (13), and in that to transfer the seized yarn (80) to the new tube (12A) fed onto the bobbin support arm (9) a single manipulation arm (90) is provided for, said arm (90) being able to rotate in two substantially mutually orthogonal planes and having a hook-shaped end part (91), constituting said yarn seizing member, said hook-shaped end part (91) containing said cutting member (92,93) and said arm (90) being further provided with an L-shaped introduction member (97), constituting said yarn positioning member, which is able to rotate about said arm (90) and to bring the yarn end of the full bobbin (11) withdrawn by said hook-shaped end part (91) into a position in front of the mobile holding centre (10) of the bobbin support arm (9) in order to be clamped between said holding centre (10) and the bottom end of the new empty tube (12A) when the holding centres are closed together, and in that it further comprises a member for rotating the tube (12A), after said holding centres having been closed together and the yarn (80) having been clamped, in order to wind the initial turns thereon and thus connect the yarn to the tube (12A), said member consisting of a motor-driven belt (102) slidable between two pulleys (103, 104) and supported by an arm (100) able to descend in a plane orthogonal to the tube axis to bring said belt (102) into engagement with the tube (12A) and to rotate it. A device as claimed in claim 1, characterized in that the bobbin discharge chute (13) is provided with a yarn lead-in notch (81) from which the hook-shaped end part (91) of said arm (90) seizes the yarn (80). A device as claimed in one or more of the preceding claims, characterized by comprising pivot-mounted levers (40,41) to accompany, retain and guide the full bobbin (11) during its discharge along the chute (13). A device as claimed in one or more of the preceding claims, characterized by being supported by a mobile carriage (1) which patrols along the machine face to serve the winding heads as and when they require its intervention.

Inventors: BADIALI, ROBERTO, COLLI, LUIGI
Applicants: SAVIO S.P.A.
Application year: 1988
Main classification: B65H65
IPC codes: B65H54, B65H65