GB769988A - Improvements in wrenches - Google Patents

Abstract

769,988. Wrenches. WILLIAMS & CO., J. H. May 24, 1955, No. 14993/55. Class 61 In a wrench of the kind in which adjustment' is effected by a worm engaging a rack on the sliding jaw, the worm 18 is slidably mounted on a shaft 19 which is slidable in the head 11 of the wrench and yieldable means are provided in the head for holding the shaft in either of two limiting positions in one of which positions the worm is locked against rotation and in the other of which positions the worm is rotatable. As shown the shaft has two peripheral grooves 22, 22a either of which may co-operate with a split spring ring 27 accommodated in a counter-sink 26 of the bore 25 in the worm. An end portion 20 of the shaft is splined or of regular polygonal form for registry with at least a portion x of the bore 21 in the head. The bore in the worm has a portion 24 of polygonal cross-section the polygon having a number of sides which is an integer multiple of the number of sides on the part 20 of the shaft. To lock the worm against rotation, the shaft 19 is moved manually to the right against the tension of the spring ring 27 which rides over the portion 20b of the shaft from engagement with the groove 22a into engagement with the groove 22, a splined portion 20a of the shaft being moved into registry with the splined portion 24 of the worm. In a modification the shaft is locked in either of the two limiting positions by a spring pressed ball. In another modification (Fig. 6, not shown) the cross-section of the portion x of the bore in the head is a polygon which has a number of sides that is an integer multiple of the sides on the shaft and the worm 18 has a polygonal bore. The right hand end of the shaft is reduced to allow rotation thereof in the unlocked position of the worm the latter being rotatable with the shaft.