Safety hook

Claim 1

A safety hook having a clevis with spaced arms adapted for attachment to a load and having registering apertures in its spaced arms, said apertures being elongated in the direction of load application to the clevis, a hook having a circularly apertured eye portion adapted to extend between said clevis arms with its circular aperture registering with the elongated apertures in the arms, a pivot pin of circular cross section extending through the registering clevis and hook apertures, said pin and hook being rectilinearly moveable within said elongated apertures in the clevis arm, said clevis having a closure arm spanning the open side of said hook, cooperating abutment means on said hook and said clevis engaged when said hook is at one limit of its rectilinear movement within said clevis arm apertures to lock said closure arm across the open side of the hook, said cooperating abutment means taking the form of a surface formed on said clevis and extending between the spaced clevis arms and an opposing surface extending from the periphery of said eye portion of the hook, and cooperating cam elements on said clevis and said pivot pin for selectively holding said pin and hook at said one limit of movement within the clevis arm apertures or freeing said pin and hook from said motion limit to permit disengagement of said cooperating abutment means to release said arm from its locked position across the open end of said hook.