Spur gear and hand tool in which it is used.

摘要

A spur gear (44,54), according to one aspect of the invention, is formed on an axially elongated rotatable member (32) with gear teeth (44) which extend axially and radially and are formed each with an extension (48) which affords support for and tapers from the corresponding tooth (44) towards the axis of the rotatable member (32) and the root thickness of which tapers away from the corresponding tooth (44) towards a point. In another aspect, the invention provides a hand tool preferably employing the spur gear (44,54) defined as a tool drive means and having an elongated hollow enclosure comprising two complementary half-shell parts (12) connected at a common end by a hinge (80) and having respective registering openings at the other end for rotatably supporting a tool having a shaft (32) and tool drive means (44) fixed thereto, locking means being provided to hold the shell parts (12) together with the tool shaft (32) in the openings and the tool drive (44) means therebetween, the half-shells (12) being releasable by said locking means so that they can be opened around the hinge (80) like a beak, providing space to remove one tool and substitute another.