Anti-backlash nut assembly

In a worm gear jack comprising a lifting screw, having a longitudinal axis, a worm gear having a center threaded portion mating with said lifting screw, an anti-backlash nut having a center threaded portion adapted to engage said lifting screw, and a plurality of driving pins coupling said worm gear to said anti-backlash nut and adapted to provide unified rotational movement of said worm gear and said anti-backlash nut while permitting limited axial displacement therebetween, the improvement comprising a plurality of cylindrical cavities formed in axially aligned, mating portions of said worm gear and said anti-backlash nut, each of said pins housed in one of said cavities, each said cavity extending along the entire length of a pin disposed therein.

In a worm gear jack comprising a lifting screw having a longitudinal axis, a worm gear having a central threaded portion for threaded engagement with said lifting screw and an anti-backlash nut having a central threaded portion for threaded engagement with said lifting screw, a plurality of driving pins coupling said worm gear to said anti-backlash nut and permitting limited axial movement of said anti-backlash nut relative to said worm gear while permitted unified rotation of said worm gear and said anti-backlash nut, the improvement comprising drive pin support means formed between mating sections of said worm gear and said anti-backlash nut, respectively, said drive pin support means comprising a plurality of axially extending substantially cylindrical enclosures proportioned to extend along the entire length of said driving pins, each of said driving pins disposed in one of said enclosures in co-axial array around said longitudinal axis.

In a worm gear jack comprising a lifting screw having a longitudinal axis, a worm gear having a central threaded portion for threaded engagement with said lifting screw and an anti-backlash nut having a center threaded portion adapted to engage said lifting screw, and a plurality of driving pins coupling said worm gear to said anti-backlash nut and adapted to provide for unified rotational movement of said worm gear and said anti-backlash nut while permitting limited axial displacement therebetween, the improvement comprising boss means carried by either said worm gear or said anti-backlash nut, collar means carried by the other of said worm gear or said anti-backlash nut, said boss means positioned in said collar means, a plurality of hemi-cylindrical recesses formed around said boss means with each disposed in parallel to said longitudinal axis, a plurality of hemi-cylindrical recesses formed along an inner surface of said collar means, said boss means recesses in matching axial alignment with said collar means recesses to form a plurality of substantially cylindrical enclosures, each of said driving pins positioned in one of said enclosures, said collar means recesses supporting said driving pins along the entire axial length of said pins.