Automatic locking sliding nut

Claim 1

An automatically locking slide nut comprising: a nut including a partially threaded hole having an enlarged open end in a generally flat load-bearing surface thereof, said partially threaded hole being defined by a threaded hole for axially receiving and mating with a threaded shaft when said nut is in a first position with an axis of said shaft substantially coaxial with a longitudinal axis of said threaded hole, and a nonthreaded hole intersecting said threaded hole at an acute angle for axially and slidably receiving said shaft when said nut is in a tilted and second position with said axis of said shaft substantially coaxial with a longitudinal axis of said nonthreaded hole, said axes of said threaded and nonthreaded holes intersecting at said acute angle; and means for automatically locking said nut in said first position when said shaft is extending in a vertical direction, said automatic locking means including an annular washer having a generally flat bottom surface perpendicular to the washer axis with the outer edge of said washer parallel to the washer axis, with said washer dimensioned for ridiNg on said threaded shaft with a bottom engaging an upper corner portion of said nut to move upwardly and downwardly with said nut as said nut is moved vertically on said shaft in said tilted position and for dropping by gravity into a locking position on said bearing surface and against said threaded shaft when said nut is tilted to said first position, said washer having a thickness greater than a spacing of the threads on said shaft, a central hole larger by a predetermined radial clearance than said shaft for loosely receiving said shaft, and a substantially circular outer edge, retaining means including a first shoulder extending upwardly from said bearing surface of said nut and having an inner arcuate surface parallel to the nut threaded hole axis for engaging said outer edge of said washer while a portion of an inner peripheral edge of said washer bears against said shaft to define a wedge between said shaft and said first shoulder to prohibit tilting of said nut from said first position, said inner arcuate surface of said first shoulder being formed on a radius substantially equal to an outer radius of said washer and extending from a center displaced by substantially said radical clearance from said londitudinal axis of said threaded hole away from said arcuate surface, and a second shoulder extending upwardly from said load-bearing surface opposite said first shoulder and including an arcuate surface formed on said radius forming said first mentioned arcuate surface.