Patent GB-1167876-A (GB)
Title: Method and Apparatus for Manufacturing Coupling Link Free Gaps in Sliding Clasp Fastener Forming Strip.
IPC: A44B19/58
Filed: 1966-10-11
Abstract: 1,167,876. Sliding clasp fasteners. TALON, Inc. 11 Oct., 1966 [22 Oct., 1965], No. 45488/66. Heading E2S. A method of manufacturing a coupling link free gap in a sliding clasp fastener forming strip which is of the kind including two strip halves 10, 12, each of which strip halves comprises a length of carrier tape 16, 18, and a filamentary structure forming a series of U- shaped heel portions 22, 24 on alternate sides of the tape, said U-shaped heel portions being attached to the surfaces of the tape by means 26 passing over the limbs thereof, with each heel portion, other than those at the ends of the structure being joined at one end to the preceding heel portion and at the other end to the succeeding heel portion by a U-shaped coupling link 20 disposed at an edge of the tape, comprises severing coupling links from the respective heel portions along a length of the strip and moving piercing needles each having a tapered head with a sharp point, substantially normally towards the surface of the fastener forming strip such that the point of each piercing needle enters the strip between the limbs of a respective U-shaped heel portion and on further movement, each piercing needle, due to its progressively larger cross-section along its length in a direction away from the sharp point, slidably engages the inner surfaces of the U-shaped heel portion to displace said portion out of engagement with said means attaching it to said carrier tape, thereby to eject said heel portion therefrom. The apparatus described for carrying out the method comprises an elongated cutting punch 30 carried by a movable upper support member 32 which in operation is actuated to impart reciprocal movement to the punch 30 substantially along its vertical axis, and a pair of stationary elongated die pads 34 and 36 located on opposite sides of an elongated groove 38 in a stationary lower support member 40. A plurality of the piercing needles 42 having enlarged heads 44 tapering to a pointed tip 46, are disposed in two parallel rows on opposite sides of punch 30, the needles in each row being equally spaced; the die pads 34 and 36 have corresponding apertures 48 to receive the needles and the spacing between adjacent needles and apertures in each row corresponds to the spacing between adjacent heel portions. The apparatus is intended for gaping both strip halves simultaneously the halves either having their rows of coupling links interlocked or with the rows of links separated by a small space. The punch 30 on the down stroke of support member 32 enters the groove 38 so that cutting edges 33 and 35 of the die pads co-operate with opposed edges 37 and 39 of the punch to sever the coupling links from the heel portions substantially simultaneously therewith; the needles 42 pierce the portion of each tape intermediate the heel portions and threads 26 which secure the heel portions to the tapes; the needles move the heel portions out of engagement with the threads 26 after which these portions are removed by any convenient means such as for example air suction. The needles need not be combined with the punch and die pads but can be separate therefrom and if desired only one needle can be provided for each strip half the strip half being indexed in a uniform manner past the needle so that the heel portions are removed in turn.