Patent GB-542177-A (GB)
Title: Improvements in or relating to the manufacture of sliding clasp fasteners
IPC: B29D5/02
Filed: 1940-06-28
Abstract: 542,177. Sliding-clasp fasteners. LIGHTNING FASTENERS, Ltd. (Talon Inc.). June 28, 1940, No. 11011. [Class 44] [Also in Group V] Stringers for sliding-clasp fasteners having non-metallic fastener members of thermo-plastic material are produced by forming blanks from a strip of material, bringing them to plastic condition by heat, forming them by dies, and mounting in spaced relationship on the tape, the last two steps preferably being effected substantially simultaneously, the members being individually controlled throughout the operation to ensure presentation to the tape in correct orientation. As shown, blanks of U or Y form are stamped by punch 10 and die 11 from a flat strip 7 of thermo-plastic material fed intermittently by rollers 8, 9. A turntable 14 having step-by-step .anti-clockwise rotation is provided with radial grooves housing slidable carriers 16 each adapted at its outer end to receive a blank, movement of the table being arrested with a carrier immediately below the punch. Normally, radial movement, of the carriers is prevented by upstanding ribs 20 thereon engaging in an annular groove 21 in the lower, face of a fixed cover 19. Rotation of the table by steps through 270 degrees, during which the blank is brought into plastic condition by heat from an electrically heated chamber 18, brings a carrier to rest in position beneath a radial slot 26 in the cover, through which a finger 25 depending from an arm 24 engages between ribs 20. Arm 24 is then oscillated to move the carrier radially outwards and transfer the blank to the space between suitably shaped ends of dies 22 carried by slidable members 33 mounted on a hollow bedplate 32 through which cooling liquid is circulated from pipes 35 (one shown). In this position the legs of the blank embrace the beaded edge of the stringer tape 2 which is fed step by step over a roller 29 and vertically downwards with one edge between guides 30 on a plunger 23, the opposite edge of the tape being guided by an adjustable 'slotted member 31. Plunger 23 then descends and dies 22 are moved inwards to bring the blank to fastener form and clamp it on. the tape, a finger 27 on the plunger providing the usual recess in one face of the fastener member. When after return of parts 22, 23, the tape is moved onwards, the affixed member is received between and given final compression by secondary dies 36, 37 as the dies 22 are treating the next succeeding member. Downward movement of parts 10, 23 is effected by rods 12, 28 operated by means not shown. The springs for returning parts 10, 23, and the means for operating the other moving parts are also not shown. The fastener members may be secured to the tape by clamping only, but preferably, are finally secured by treating the completed stringer to solvent action as described in Specification 426,644, or by previously wetting the tape with solvent as in Spefication 391,146 The invention includes, as modifications, cutting the blanks from a rod of suitable cross-section, conveying blanks through a heated chamber to the forming dies by a moving belt mechanism, and adopting fastener members of such form that'they may be made by two-part dies without the co-operation of members 23, 27.