Patent GB-712025-A (GB)
Title: A method of and apparatus for making sliding clasp fasteners
IPC: B21D53/50
Filed: 1952-10-10
Abstract: 712,025. Making sliding-clasp fasteners. PETERHANS, J. Oct. 10, 1952, No. 25450/52. Classes 83' (2) and 83 (4) [Also in Group XXV] Angular bending.-A method of producing a sliding clasp fastener of the type which consists of a plurality of sliding clasps which engage beadings at the edges of the opening and which clasps are connected together by links so that the clasps are spaced a predetermined distance apart when the opening is closed comprises cutting lengths each suitable for the production of a sliding clasp from wire or strip material, forming each length into a U-shaped member the legs of which are narrower than its yoke, inwardly.kinking the legs.of the U-shaped member, laying a cord in each kink and bending the free ends of the legs around the cords to grip them. The fastener is made by a machine which comprises a base-plate 1, Fig. 1, and an upper plate 2 joined by pillars (not shown). A driving,shaft 3 which is driven by a pulley 6 is carried in bearings 4, 5 and carries an eccentric 9 and cams 7, 8, 10, 11 and 12 for driving the various-parts of the machine. Cam 7 operates a feeding device for the wire or strip from a supply reel (not shown) through a system of levers and bell cranks. The feeding device consists of a slide 17, Fig. 3, carrying spring-loaded levers 18-21 which are connected to rollers 22-25 having flats for gripping the wire or strip. The rollers grip the wire or strip, when the slider moves to the right as shown in Fig. 3 and releases it on movement of the slider to the left. A pair of spring loaded gripping rollers 32, 33 prevent the Wire or strip moving-backwards. The wire or strip is fed over bar 38, Fig. 4, which extends the length of the machine and which forms a fixed lower die at this point for a press tool and a. length of wire or strip is cut off and bent to U-shape by a reciprocating part 49 attached to a cross beam 44 which is moved through a second cross beam 46 by the eccentric 9. When wire is used the press tool flattens the centre section of the part cut off to increase its width and when strip is used, the ends of the part cut off which are to form the legs of the 'clasp are cut to reduce their width. The partially formed clasp is fed along the bar 38 by a feeding device 37 which consists of a fork shaped part 37<SP>1</SP>, reciprocated longitudinally of the bar 38 by the cam 8 through levers. The partially forined clasp is thus first moved under a tool Fig. for producing a kink in each leg ; this tool comprises a pair of levers 55 which, co-operate with the bar 38 and which are moved towards and away from the bar 38 by the cam 10 through linkages. The clasp 'is then moved underneath a cord feeding device which consists of two nozzles 67 and which lays the cords in the kinks. The clasp is then moved to a tool which bends the legs of the clasp round the cords to grip them. This tool, Fig. 6, comprises a pair of levers 69 which are moved inwardly against the bar 38 by the cam 11 trough linkages. The clasp is held on to the bar 38 during this operation by a member 74 which is adjustably forced into contact with the clasp by springs 77 and which is raised to release the clasp after the legs have gripped the cords by means of pins 72 on the member 74 which are forced out of grooves 71 in the levers 69 by backward movement of the levers. The spacing of the clasps on the cords. is .determined by a device operated by the cam 12. This comprises a member 87, Figs. 1 and 9, which is mounted so that it can slide vertically on a bridge. 86. which in turn is mounted so that it .can. slide horizontally on guide rods 84. The bridge is moved by the cam 12 through linkages and the vertical movement of the member 87 is accomplished by adjustable pins 94, 95 which each have a conical end. The member 87 has an aperture 93 at its upper end which tapers inwardly from both sides. During the movement of the bridge 86 to the right in Fig. 1, the member 87 is in its lowest position in which it engages a clasp which has been secured to the cords and moves, it along the bar 38. This movement draws the cords through the clasp in the clamping tool since the clasp therein is held in place by the member 74, the clamping being arranged to take place after the movement to the right of the member 87 has stopped. As it moves to the right, the aperture 93 engages the pin 95 and the conical shapes of both the pin and the aperture raises the member 87 vertically to release the clasp. The bridge then moves to the left with the member 87 in its raised position and when the aperture 93 engages the pin 94 the member is moved vertically downwards into contact with a clasp, the cycle then repeating. The member 87 is held in either position by spring loaded balls 91 which engage notches 88 or 89.