Precision safety ring-shaped hook

Abstract

A precision safety ring-shaped hook provides a timing gauge structure which is composed of a sliding groove, a pair of rail members, and a block pin. Each of the rail members has an arc surface. When a first locking axle is moved to an open slot, a first end of a hook body is moved away from the first guiding member and, at the same time, a block pin moves to the arc surface area, so that when the first locking axle is swung in a hook cavity of the hook body, a driving pin is able to position at the arc surface and thus a locking member can be guided by the arc surface to open the opening of the hook body. Accordingly, the opening or shutting of the opening of the hook body by the locking member can thus be precisely operated at one time to provide an advance precision value for the hook and eliminate the interference and impacting drawbacks.