Patent GB-782209-A (GB)
Title: Method and apparatus for the manufacture of sliding clasp and tab assemblies
IPC: B21D53/52
Filed: 1955-04-12
Abstract: 782,209. Making sliding clasp fasteners; bending; shearing. GROVES, N. L. (Conklin, R., Seidler, J., and Rubino, D.). April 12, 1955, No. 10389/55. Classes 83 (2) and 83 (4). Slide and tab assemblies 10, 12, Fig. 5A, for sliding clasp fasteners are formed and assembled together in a single machine by feeding strip metal 101, Fig. 4, into the machine from one side and forming it in successive operations into an unbent slide 10, Fig. 2, still connected to the strip, feeding strip metal 12<SP>1</SP> into the machine from the opposite side and forming it in successive punching operations into a tab 12 with open jaws 18 still connected to the strip, Fig. 3B (not shown), severing the foremost slide 10 from its strip and then bending it to form a U-shaped slide 10, Fig. 5A, feeding the foremost tab 12 into engagement position with the U-shaped slide, holding the tab in this position and severing it from its strip, fastening the tab to the slide and ejecting the assembly from the machine. The upper press tools are mounted on an upper die member 70, Fig. 4, secured to a reciprocating head 56 of the press, which is preferably driven by an electric motor, and the lower dies are mounted on a lower die member 66 secured to the press bed 50. Guide rods 72 secured to the head 56 engage within recesses 72<SP>1</SP> in the bed 50 for ensuring alignment of the top and bottom tools. The strip 121 is fed into the machine by a reciprocating slider 75 actuated by a cam 75<SP>1</SP> on the press head 56. Holes 80, Fig. 4A, are first punched in the strip and are subsequently engaged by a pawl 90 pivotally mounted on the slider 75 and biased downwardly by a leaf-spring 92. A cam roller 78 is provided on the slider for engagement with the cam 75<SP>1</SP> and after the feed stroke the slider is returned by a spring 86. A similar feed mechanism 74, Fig. 4, is provided for the strip 10<SP>1</SP>. The bail 20, Fig. 5A, for receiving the tab, is pressed out of the strip 10<SP>1</SP> by a punch 120, Fig. 6, and after a further advance the unbent slide 10 is sheared from the strip 10<SP>1</SP> by a shear 125 and is then bent to U-shape by an upper die 100 backed by a lower spring-loaded die 110. Die 100 biased by a spring 105, is slidably mounted in the reciprocating head 56 and during the downstroke spiing-biased keys 107, Fig. 5A, engage in notches 106 and move the upper die to bend the slide by pressing the latter into an opening 109, Fig. 6, in the die member 66. The stroke of the bending dies 100, 110 is limited by a shoulder 117 on lower die 110 engaging a fixed shoulder 118 and thereafter the press head continues to move whereby the keys 107 are disengaged from their notches 106. During the upstroke of the head the bending dies with the bent slide gripped between them, are raised by pressure of a spring 111 and during this time the foremost tab 12 having had its jaws 18 spread by a punch 127, Fig. 6, and then fed forwardly, is held by a spring- loaded plunger 129 and then severed from thestrip 121 by a punch 128. The upward move ment of the slide 10 ceases with its bail 20 in alignment with the tab jaws and the latter are then closed on to the bail by a pair of spring- biased transverse tools 133, 134, Fig. 5A, actuated during the upstroke of the head 56 by cam rollers 139 carried thereby. Thereafter, the keys 107 re-engage the notches 106 in the bending die 100 and raise it thus permitting the tab and slide assembly to be ejected, for example by means of an air blast.