Skeining device

Abstract: A fixed guide 25 is mounted on a shuttle 23 for forming wraps around a rotatable needle 13 and rear hook 14. The guide 25 has a chosen shape to allow uninterupted through feed of the wire 26 when no skeining is being carried out and to ensure reliable wrapping during skeining.

Description: This invention relates to skeining devices. The leads to electrical coils, such as solenoid and relay coils, are normally reinforced by being skeined, i.e. multiplexed and then twisted. This procedure is frequently and normally carried out by hand, which is a slow, labour-intensive, unreliable and expensive practice. It may also reduce the efficiency of coil winding which has to be stopped while the leads are skeined. Automatic and semi-automatic skeining devices are already in use such as those described in UK Patent Specification 2049748. The present invention relates more particularly to improvements in such automatic machines. In Patents Specification GB-A-2049748, the apparatus comprises retaining members located adjacent the path of the wire through the machine and spaced from one another along the path, a shuttle member carrying a wire guide in the form of an eye, means for moving the wire guide around a closed loop path surrounding the retaining members to retain the wire on the members to multiplex the wire, said moving means comprising drive means for reciprocating the shuttle member along a rectilinear path substantially parallel to the path of the wire through the device and reciprocating the wire guide laterally of the path of the wire through the device to follow the closed loop path, means for rotating one of the retaining members to twist the multiplexed wire, the rotatable retaining member being in the form of a hook, a positioning motor for returning the hook to a correct orientation at the conclusion of rotation, means for releasing the skein from the retaining members, and controls which include a proximity switch for stopping the drive means at a time when the shuttle is clear of the multiplexed wire and simultaneously starting the rotation of the rotatable retaining member. The shuttle has guides 2 (see Figs. 1 and 2) through which the wire is threaded and more particularly through which the wire is drawn when skeining is not being carried out. In practice the tortuous path through the guides 2 tends to have a detrimental effect on the outer surface of the wire and can introduce strains due to the sudden opposite bending caused as the wire passes through the guides 2. Ideally, the wire should pass through the guide 2 without rubbing on the guide at all when skeining is not taking place. In GB-A-2 114 032, it has already been proposed to arrange for the guide 2 to be rotated through 90° for straight through feeding to achieve the desired effect. As such this inherently introduces extra moving parts and appropriate control or synchronising mechanisms. According to the present invention there is provided a skeining device comprising first and second retaining members positioned adjacent the path of wire through the device, a wire guide in the form of an eye mounted on a shuttle, means for moving the shuttle to move the wire guide in a closed loop path about the retaining members to multiplex the wire on the retaining members, and means for twisting the multiplexed wire to form a skein, characterised in that the wire guide is mounted on the shuttle in an orientation which is constant during passage of the wire through the device and during a multiplexing operation, the orientation being such that the wire passes through the guide in a straight line path during passage of the wire through the device. A skeining device according to the invention will now be described by way of example with reference to the accompanying drawings in which:- Figure 1 shows a general layout of the device; Figure 2 shows a part of the device for through feeding of wire; Figure 3 shows the part of the device in one position during a multiplexing operation; Figure 4 shows the part of the device in another position during a multiplexing operation; Figure 5 shows another form of shuttle guide for the device. Referring to the drawings, in Figure 1 a skeining device has a wire feed-through motor 10, a multiplexing drive motor 11 for a chain (not shown), a tachometer 12 for the motor 10, two retaining members in the form of a rotatable twister needle 13 and a rear hook 14 mounted on the plunger of a solenoid 15 carried by a carriage 16. The needle 13 is driven in use by a motor 17 and the rotation of the needle is monitored for relative position and number of revolutions by a counter 18. A carriage drive motor 18A, monitored by a tachometer 19, moves the carriage 16 as required towards and away from the needle 13. A flyer 20 is positioned adjacent an input for the wire into the skeining device and has two operative positions. A wire gauge monitor 21 and wire tensioner 23 are also provided. A microcomputer 22 is programmed to control and monitor the operation of the skeining device. In Figure 2, a shuttle 23 is driven by a chain 24 (which in turn is driven by the motor 11 of Figure 1). A fixed circular guide 25 shown in section is mounted on the shuttle 23 for through-feed of the wire 26 between a fixed circular inlet guide 27, also shown in section, and the rotational axis of the rotatable twister needle 13. The chain 24 and shuttle 23 are stationary as no muliplexing is taking place while the wire feeds through the skeining device to a coil winding apparatus (not shown) but situated to the left of the needle 13. It will be noted that the guide 25 is arranged such that the wire 26 passes uniterruptedly through the guide 25 in a manner so that the wire does not touch or barely touches the inner surfaces of the guide 25. In Figure 3, the shuttle 23 is shown having commencing a first turn of a multiplexing sequence so that the wire 26 is positioned around the rear hook 14. The shuttle 23 is moving towards the rotatable needle 13. At the extreme left hand position of the shuttle 23 as shown in Figure 4, the wire 26 is hooked onto the needle 13 before the shuttle returns towards the rear hook 14. It will be noted that the wire 26 is engaged by the hook 14 at this position on the same side as the first turn. However, in practice as the shuttle 23 moves to the right the wire 26 is pulled away under the hook 14 before the shuttle 23 lays the next turn onto the hook 14. This is normally facilitated because the hook 14 is angled a few degrees from the vertical, that is upwards out of the plane of the Figure 4, tending to more easily allow the wire 26 stretching between the guides 25 and 27 to be released under the hook 14 as the shuttle moves to the left. This non-vertical angle of the needle is predominently provided to improve the wrapping of the wire 26 on to the needle 14 as the shuttle moves anti-clockwise around the needle 14 during multiplexing. At the completion of multiplexing, the needle 13 is rotated in the normal manner to form a skein and then the hook 14 withdrawn to release the skein for its onward passage through the hollow centre of the needle 13 in the usual way. Further details of the device are described in UK Patent Application No. 8716317. In Figure 5, a guide 50, shown in section, to replace the guide 25 of Figures 2 to 4 has a generally triangular cross-section with rounded corners and is provided with an extension or foot 51 for fixedly mounting the guide onto the shuttle 23. The top section of the guide 50 must be dimensioned to provide a loop extending above and below the hook of the twister needle 13 (shown dotted) and also pass below the level of a stripper plate 14A at the base of the hook 14. The bottom section of the guide 50 must be positioned so as to allow free or uninterrupted passage of the wire for through-feeding when no multiplexing is taking place. Such restraints never-the-less allow a wide selection of shapes and sizes of suitable fixed guides 50 to be provided. However, the design restraint which required that the wire must be always held below the bottom edge of the hook 14 for return of the shuttle from the position shown in Figure 4 made it impossible to achieve a practical reliable shuttle guide which did not scuff the wire during through-feed or had to be swivable between a through-feed position and a multiplexing position. Realisation in practice that such design restraint was not necessary enables a much-improved skeining device to be provided and completely opens up the range of fixed shuttle guide designs that can be used. Thus, the guide shape can now be perfected for providing guide for reliable multiplexing which are also suitable for uninterrupted through-feed so that the wire is not scuffed or strained during the through-feeding when no skeining is taking place. It will be noted particularly with reference to Figure 2 that a straight line exists extending through the guide 25 and 27 to the axis of the needle 13. This means that a straight wire threader can be fed through the skeining device at the commencement of operation. As will be appreciated this greatly fascilitates the initial threading of the wire 26 which is often of very fine gauge and is very difficult to thread into a tortuous path, particularly through the tortuous path of shuttle guides of skeining devices presently in use.

Claims: A skeining device comprising first and second retaining members (13,14) positioned adjacent the path of wire (26) through the device, a wire guide (25,50) in the form of an eye mounted on a shuttle (23), means (11,24) for moving the shuttle (23) to move the wire guide (25,50) in a closed loop path about the retaining members (13,14) to multiplex the wire on the retaining members (13, 14), and means (13, 17) for twisting the multiplexed wire to form a skein, characterised in that the wire guide (25,50) is mounted on the shuttle (23) in an orientation which is constant during passage of the wire through the device and during a multiplexing operation, the orientation being such that the wire passes through the guide (25,50) in a straight line path during passage of the wire (26) through the device. A skeining device as claimed in claim 1, characterised in that one of the retaining members (14) is angled away from the path of the wire (26) through the device, so that as the guide member (25,50) circles around the retaining member (14) to lay against the retaining member (14) a first run of the wire (26) downstream of the guide member (25,50), and a second run of the wire upstream of the retaining member (14) is momentarily caught on the retaining member (14) and then flips off the retaining member (14). A skeining device according to claim 1 or 2 , characterised in that the guide (50) has a generally triangular cross-section with rounded corners and is provided with an extrusion or foot (51) for fixedly mounting the guide onto the shuttle. A skeining device according to claim 3, characterised in that the top section of the guide (50) is dimensioned to provide a loop extending above and below the hook of a rotatable retaining member (13) and also pass below the level of a stripper plate at the base of the stationery retaining member (14), a bottom section of the guide (50) being positioned so as to allow free or uninterrupted passage of the wire for through-feeding when no multiplexing is taking place.

Inventors: CINIGLIO ALEXANDER JAMES, SQUIRE NEIL CHRISTOPHER, CINIGLIO, ALEXANDER JAMES, SQUIRE, NEIL CHRISTOPHER
Applicants: EVENOAK LTD, EVENOAK LIMITED
Application year: 1989
Main classification: H01F41
IPC codes: H01F41, B65H54