Crane type hoist hooks have been provided and taught in the prior art to include gate latches for closing the mouths of such hoist hooks. In some structures dog pins have been used in combination with the latches to hold the gate latches in their closed positions across the mouths of the hooks. U.S. Pat. No. 2,927,358 is one example of a hoist hook having this type of latching mechanism. The concept of a combined hook and latch wherein the latch is pivotally mounted on the hook and normally biased to its closed position and which includes an interlock member that is pivotally mounted on the latch and movable to a first position locking the latch closed, i.e. prevent opening of the latch and to a second open position allowing the latch to be pivoted to an open position, is described in U.S. Pat. No. 3,575,458.
USPTO Backgrounds
USPTO Backgrounds