Screw spindle
OwnerFranz Arnoldinventor
Life of this patent
Estimating the term…
Abstract
A screw spindle drive comprising a spindle with one or more thread grooves of circular cross-section, a nut with a complimentary groove or grooves, and a closed ring of balls in each raceway formed by a groove in the spindle and a corresponding groove in the nut has the pitch of each raceway less than the product of the ball diameter and the number of raceways. The thread grooves have a radius of curvature equal to that of the balls but their depth is less than this radius. A return groove in the nut has only to be deep enough to allow the balls to ride over the ridge between turns of the thread groove. The balls can be held by permanent or temporary cages for ease of assembly.
Claims11
In a screw spindle drive comprising a screw spindle having at least one thread groove of circular cross section, a nut having a thread groove complementary to said thread groove on said screw spindle to form a ball raceway therebetween, and a closed ring of equal diameter balls in said ball raceway, the improvement comprising wherein the pitch of said thread groove on said screw spindle is less than the diameter of each of said balls.
In a screw spindle drive comprising a screw spindle having plural thread grooves of circular section, a nut having plural thread grooves complementary to said thread grooves on said screw spindle to form a plurality of coextensive ball raceways therebetween, and plural closed rings of equal diameter balls in said ball raceways, the improvement comprising wherein said pitch is less than the result obtained by multiplying the diameter of one of said balls by the number of ball raceways.
Dependencies are inferred from the claim text.