Adjustable pressure assembly for a rotating plate in an automotive steering box

摘要

An adjustable steering box has a worm gear with a worn region and a less-worn region, and the worm gear is engaged with pins on a rotating plate which is coupled to a steering mechanism. The rotating plate has an engagement position which is secured by an annular contact surface of an adjustable pressure assembly. The center of the annular contact surface has a pressure pin which protrudes and makes pressure contact with the rotating plate, thereby pressing the pins into engagement with the worm gear in worn regions with a pressure which compensates for play caused by worn regions of the worm gear or pins.

主权项

1. A steering box having:
an enclosure; a worm gear with threads formed therein and having an axis of rotation and coupled to a control shaft, said worm gear capable of rotating about said worm gear axis in said enclosure; a rotating plate coupled to a steering arm shaft, said steering arm shaft substantially perpendicular to said worm gear axis and able to rotate in said enclosure, said rotating plate having a substantially planar pressure surface opposite a pin surface which includes at least one tapered pin which engages with said worm gear threads, said worm gear threads having a worn region in a central extent whereby, for a given tapered pin engagement depth, said tapered pin has greater clearance to said worm gear in said worn central extent than in a comparatively less worn region on either end from said central extent; an adjustable pressure assembly having a substantially non-deformable outer annular contact surface for contacting said substantially planar pressure surface of said rotating plate pressure surface when said tapered pin is engaged with said worm gear in said unworn region, said adjustable pressure assembly also having an inner pressure pin protruding through said annular contact surface and providing pressure to said rotating plate when said tapered pin is engaged with said worm gear in said worn region of said worm gear threads; where said non-deformable outer annular contact surface maintains an interference clearance from said tapered pin to said worm gear in an unworn region, and said pressure pin contacts said rotating plate pressure surface in said worn regions, thereby increasing a tapered pin engagement depth and thereby reducing a clearance between said tapered pin and said worm gear in said worn regions.