Wedge-locking fastener assembly with a cammed flange
AssigneeHong Kong Disc Lock Company Limited
InventorAlistair N. McKinlay
Life of this patent
Estimating the term…
Abstract
A wedge-type flanged fastener assembly is provided for holding two or more workpieces together without loosening due to vibration or shock forces. The assembly includes a nut and lock washer having mating cam surfaces contoured to achieve a high strength wedge lock resistance to unloosening movement of the nut. The lock washer is captively retained on the nut by an annular flange extending from the nut through the central opening in the washer. Several variations of a flanged wedge type fastener are disclosed.
Claims13
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.
A wedge-action fastener assembly comprising:
- a threaded shank extendable through a workpiece;
- a radially enlarged fastener head means turnable around the shank axis to cause the fastener assembly to exert an axial gripping force on the workpiece;
- and a lock washer interposed between said radially enlarged fastener head means and said workpiece;
- said radially enlarged fastener head means having a first cam surface facing said lock washer, and said lock washer having a second cam surface facing said fastener head means;
- each of said cam surfaces comprising a number of circumferentially-spaced ramps and a corresponding number of interconnecting shoulders;
- each of said ramps being sloped at a relatively slight acute angle to a plane normal to the shank axis;
- each of said shoulders 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 shank comprising a continuous thread having a pitch distance;
- said shoulders having axial thickness dimensions less than said thread pitch distance;
- said first and second cam surfaces being mated so that when said fastener head means is turned in a tightening direction, the fastener head means urges the washer axially in the tightening direction, and when the fastener head means is turned in the opposite, loosening direction and the washer is fixed with respect to a workpiece, the fastener head means becomes wedged against movement in the loosening direction.
Dependencies are inferred from the claim text.