GB642803A - Improvements in or relating to the manufacture of sliding clasp fasteners - Google Patents

Abstract

642,803. Sliding-clasp fasteners. MARLOW, E. H. April 12, 1948, No. 10144 [Class 44] In a machine for making sliding-clasp fasteners, preformed strip is fed by steps into a chamber formed in a shuttle, a spreader being adapted to spread the legs of the end element in the chamber, the end element then being sheared off by movement of the shuttle relative to an anvil and carried to a position where it is displaced from the chamber on to the beaded edge of the tape and there secured by closing the legs. In the form of Figs. 2 and 4, the shuttle consists of a single member 31 having a chamber 44 of a length to contain one element 50. Holes 52 in the strip form legs 55, 56 which are spread apart while the element is in the chamber by a pointed spreader 45 mounted on a reciprocating plunger 40. Chamfered sides 47 of the chamber 44 allow the legs to spread and provide abutments against which they are flattened to remove sharp edges. After the spreading operation the shuttle moves upwardly shearing off the element 50 against the anvil 34 and carrying it up to a position opposite a pusher member 35 adapted to displace it from the chamber 44 and set it astride the beaded edge 54 of the tape 14, where it is secured by opposite clamping members closing the legs. The strip 12 is carried on a reciprocating table provided with gripping means which locate themselves against the projections 51 on the strip and are operative only on the forward movement of the table, being released on the return movement so that the strip advances in steps. The tape 14 is gripped by jaws above and below the element being secured thereto, the lower jaws being released after the element is fixed and the upper jaws being lifted to advance the tape to a position to receive the next element. All moving parts are operated through push rods by a cam-shaft passing under the bed of the machine. In another form, Fig. 16, the shuttle comprises two blocks 90, 91, the chamber or space between them being long enough to contain five elements. The member 91 is a shearing die and is adapted to cooperate with an anvil 101 to shear off the end element (which is already fixed on the tape) and in its downward movement to displace the lower block 90 against its supporting spring 92 until the element is disposed opposite the spreader 40. The die block 91 is, formed with a notch to engage over the projection 51 of the end element to locate it while the legs are being spread. The rest of the strip 12 is clamped in this operation by a spring loaded plunger 100, mounted in the die block 91, bearing on the strip. As the die block 91 is withdrawn the block 90 rises until arrested by a collar 96. The die block 91 rises a further amount sufficient to release the strip 12 so that it can be advanced to the next position by the feeding mechanism to position the end element on the tape where it is secured as described above. Specifications 642,802, [Group XXII], and 642,804 are referred to.