Adjustable spanner with thumb control for jaw - has knurled adjusting nut connected to jaw screw through bevel gear drive

摘要

An adjustable spanner (10) has a handle with a fixed jaw (16). A moving jaw slides on the fixed jaw and has teeth (34) which engage the teeth (36) of a screwed rod (40). A bevel gear (42) on the end of the screwed rod (40) meshes with a gear (56) on the end of the rod (50). The rod which rotates in bearings fitted in the handle of the spanner has a helical groove (52) with a steep helix angle cut in its surface. A pin attached to a sliding button (54) engages the helical groove and adjusts the span of the jaws.