Fairchild Holding Corporation

Rodney D Bolt

Graeme J Cliff

A prewinder mandrel including an elongate shaft having a threaded lead end, a slot dividing the lead end into first and second end portions, and a pair of opposing beveled edges on the first end portion. A first drive edge is located between the first and second beveled edges, a second drive edge is located on an outer edge of the second end portion, and an inclined ramp extends along the second end portion from the leading edge towards the slot. The mandrel may part of a prewinder tool for installing helical wire inserts that includes a drive mechanism coupled to the mandrel shaft and a threaded nozzle through which the shaft extends. The shaft includes a threaded intermediate region for engaging the threaded nozzle to drive the mandrel at a predetermined pitch. The lead end is inserted into a wire insert, the shaft rotated to advance the insert over the lead end until the tang engages a first beveled edge and is seated within the slot. The lead end is directed into a tapped hole and the shaft rotated to wind the insert into the hole. The shaft is then rotated in reverse, a second beveled edge and the inclined ramp slidably disengaging the tang from the slot, and the lead end is withdrawn from the hole while leaving the insert in place.

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Nunawading, Australia

Rodney D Bolt