Wedge-locking fastener assembly with a cammed flange

Claim 1

In a wedge-action annular fastener assembly comprising a nut having a threaded internal surface rotatable about an axis, a multi-sided wrench engaging head, a cam end face on the nut; an annular lock washer being capable of relative axial motion toward or away from the nut; said annular lock washer having a second cam end face interengaged with the cam face on the nut; each of said cam faces comprising a plural number of circumferentially-spaced ramps and a corresponding number of interconnecting shoulders; each ramp being sloped at a relatively slight acute angle to a plane normal to the nut rotational axis; each shoulder being sloped at a relatively steep acute angle to said plane; said shoulders and said ramps being connected at acute angles so that the respective cam surfaces have an undulating contour; the threaded internal surface on said nut comprising a continuous thread having a pitch distance; said shoulders having axial thickness dimensions less than said thread pitch distance; said cam faces being mated so that when the nut is turned in a tightening direction, the nut urges the washer in the tightening direction, and when the nut is turned in the opposite, loosening direction and the washer is fixed with respect to a workpiece, the nut becomes wedged between the ramps on the washer, and the threads on a threaded shank on which the nut is threadably mounted, the improvement comprising: the nut having an integral annular flange having a diameter at least as great as the multi-sided wrench-engaging head and the cam end face on the nut being formed on the annular flange.