Safety Purpose Lifting Hook
A lifting hook is a device used for grabbing and lifting loads by means of a device such as a hoist or crane. Lifting hooks are usually equipped with a safety latch to prevent the disengagement of the lifting wire rope sling, chain or rope to which the load is attached. Hooks may have one or more built in pulleys to amplify the lifting force.
Government Printing Office The Official Gazette of the United States Patent Office (Washington, DC: Government Printing Office, 1895)