Fastener attachment insertion device needle construction

Claim 1

In a fastener attachment member insertion device needle for inserting fastener attachment members into material, the needle including a tubular member having a mounting portion, a central portion and a front end portion, at least the central portion having a bore and a longitudinal slot along one side of the bore, the distance between the surfaces defining the slot less than the diameter of the bore, the improvement comprising a needle tip having a spoon-like hollow forward of the bore for expelling the fastener attachment member with the forward most tip portion defining a line knife edge to form an elongate slit in material upon insertion into the material, said line knife edge being a curved line and said line knife edge defined by a curved side surface and a flat side surface intersecting the curved side surface, said spoon-like hollow portion having a curved open channel defined between spaced curved side surfaces and said flat surface, which intersects said spaced curved side surfaces at the front of the channel, and said spaced curved side surfaces also intersecting sUrfaces defining said slot at the rear of said channel.