Patent GB-600541-A (GB)
Title: Improvements in apparatus and method of controlling paired operations for making slide fasteners
IPC: B21D53/50
Filed: 1946-02-04
Abstract: 600,541. Sliding-clasp fasteners. COX, L. N. (Strauss Fasteners, Inc.). Feb. 4, 1946, No. 3476. [Class 44] In a method of and apparatus for making, forming and attaching sliding-clasp fastener elements to the tapes, a turntable carrier moves consistently in steps in one direction, and is provided with element holders co-operating with mechanism at several stations spaced around the turntable ; at one station, elements are fed to the holders, at another the jaws of the elements are spread, and at two stations the elements are applied to the tapes. The sequence of operations according to the invention is as follows. A group of elements sufficient to form a given length of fastener is first applied to one tape, which is moved in steps past the table ; application to this tape is then stopped and an equal number of elements is then applied to a second tape at another station, while the first tape continues to move for a given number of steps to form an inter group spacing. The first tape is then stopped until the complete group of elements has been applied to the second tape. Application of elements to the first tape then begins again, while the second tape continues to move for a given number of steps for the inter group spacing and is then stopped while application to the first tape continues to. complete the group, and so on. By this method, feed of the elements is continuous to one or the other of the tapes, and each tape is kept moving for the number of steps required to form a length of fastener plus an inter group spacing. The apparatus shown in schematic form in Fig. 1 comprises a turn table 12 provided with element holders 13, which may either be adapted to use preformed elements, or may consist of dies which form the elements from wire stock. An element feeding mechanism F, spreading mechanism Sl, S2, and attaching stations A1, A2 are arranged around the table 12. The element attaching mechanisms at stations A1 and A2 may be driven in alternation by identical drive means, but to simplify the control mechanism, the mechanism at station A2 is allowed to operate continuously, being driven by a shaft 16, while that at station A1 is provided with a clutch 21 thrown in or out by energizing the magnets 23 or 24 respectively. Similar mechanisms for feeding the tapes T1 and T2 are provided at each station, such mechanism comprising a continuously rotating cam 31 operating a shaft 27 through a lever 30, a pawl 29 and a ratchetwheel 28, giving the shaft 27 a step-by-step rotation. Latches 32, controlled by electromagnets 33, 34 and 35, 36, co-operate with the levers 30 to start and stop the feed of the tapes. Control of the operation of the attaching and tape feeding mechanism is effected by a pair of main counters P1, P2, and a pair of auxiliary stop counters H1, H2. These four counters are driven by a shaft 40 through a reversing clutch 42 controlled by a lever 43 from a pair of electromagnets C1, C2. Each counter is provided with contacts which close when the counter indicates zero and are connected in the appropriate circuits of the controlling magnets. Before a run, one of the counters P1, P2 is set to the number of elements desired for the fastener length, the other at zero, and one of the counters H1, H2 to the number of spaces in the inter group interval, the other at zero, so that the cycle described above takes place. The contacts are actuated by the movement of a rod 51, Fig. 4, which drops into notches on the counting discs of the counters when the notches are aligned at the zero position of the discs. As it is necessary for the action to prevent closing of the contacts of the counters H1, H2 when the latter are moving in the adding direction, an extra notched disc 55, Fig. 4, having pin-and-slot lost-motion connection with one of the counter discs is provided so that contact is made only when the counter rotates in the required sense. Fig. 7 shows a mechanism for forming the fastener elements from wire stock, W, which is fed forward by jaws 67, 68, pivoted together at 69, the upper jaw 67 being pivoted on a fixed pin 70, the intermittent feed of the wire being effected by the reciprocation of a slide 73, actuated by a cam 75, pivoted at 74 to the lower jaw 68. The wire passes through a friction device 66. The fastener elements are formed by a series of punches 82, 83, 84, which respectively pierce, part and swage the'element, leaving the latter with its jaws protruding from the periphery of the table 12. A cover-plate 90 holds the elements on the table. The mechanism at stations SI, S2, Fig. 1, for spreading the jaws of the elements comprises a punch 95 actuated by a cam 96 and a spring 97. The element applying mechanism at station A1 is shown in Fig. 9.- The tape T1 passes over a friction roller 101, and is drawn upwardly in steps by a pulley 102 actuated by ratchet mechanism from a cam 31, while a cam-actuated guide 103 moves it towards the table 12 at the appropriate intervals to insert the beaded edge between the jaws of an element which are then closed by means of cam-actuated arms 110, the element being meanwhile held by a clamp 113.