GB560882A - Improvements in screw and nut gearing - Google Patents

Abstract

560,882. Screw and - nut gearing. NEEDHAM, G. Nov. 3, 1942, No. 15462. [Class 80 (iii)] Means for preventing backlash in screw-andnut gearing, comprise a nut divided longitudinally into two parts which are held together in their operative positions by collars also adjustable to move one part of the nut relatively to the other part. The nut, Fig. 2, is divided along an axial plane to produce two parts A, A<1> of which A is connected by an extension E to the machine part to be actuated. The halfends A<1> of the part A are threaded to receive collars D the crests of the threads on which engage plain surfaces on the half-ends B<1> of the part B which is slightly longer than the part A. In a modification, the nut is divided along planes inclined at less than 180‹. In a modification, Fig. 5, the collars D of Fig. 2, have teeth P to be engaged by worms Q rotatably mounted in a part O by ferrules S engaging collars R on the worm spindles. This facilitates adjustment in cases where the nuts are inaccessible. According to the Provisional Specification one part of the nut is dovetailed into the other part, the parts being secured in operative position by screws.