Self broaching fastener assembly and like self sizing fasteners

Claim 1

In a joined fastener construction including a workpiece having a hole therein, the improvement of a non-blind type, single drive broach bolt and broach collar fastener means positioned iN said hole and being operative to be installed in a single drive operation, said fastener means comprising, a pin member with a head larger than the workpiece hole and shank at one end adjacent the head and a pull portion at the other end thereof projecting from said hole beyond the workpiece, a plurality of broach teeth means on the pin, lock grooves on the pin intermediate the broach teeth and shank, a broach collar means positioned on the pin at the end opposite the head and outside the workpiece hole and adapted to be deformed into said lock grooves, said broach teeth means having a diameter greater than that of the workpiece hole whereby upon being pulled through the workpiece hole, the hole is broached to give a sizing of the hole wherein there is provided an interference fit between about 0.0012 and 0.015 inches when the shank is pulled into the hole, and said collar having an inside diameter less than the diameter of the broach teeth so that the collar is broached when the broach teeth means is pulled therethrough, and any broaching chips removed from the workpiece hole are pushed on through the collar means, all in a single drive operation wherein said collar means is finally swaged into connection with said lock grooves, and without need of any intermediate chip removal operation.