Hook

Claim 1

A HOOK FOR A HOIST ADAPTED TO CARRY AN ARTICLE HAVING AN UPSTANDING BAIL COMPRISING: A PAIR OF UPRIGHT SIDE PLATES FIXED RELATIVE TO ONE ANOTHER IN A SPACED RELATION, EACH OF SAID PLATES BEING PROVIDED WITH A VERTICAL DISPOSED SLOT EXTENDING FROM THE LOWER END THEREOF AND TERMINATING SHORT OF THE UPPER END OF SAID PLATE, THE SLOTS BEING IN REGISTRY WITH ONE ANOTHER AND PROVIDING AN OPEN THROAT TO RECEIVE A BAIL OF AN ARTICLE TO BE LIFTED; A PAIR OF MOVABLE JAWS PIVOTALLY MOUNTED BETWEEN SAID PLATES ABOUT PARALLEL TRANSVERSE HORIZONTAL AXES, SAID JAWS BEING LOCATED ADJACENT THE LOWER ENDS OF SAID PLATES AT EACH SIDE OF THE SLOTS FORMING SAID THROAT, SAID JAWS EACH BEING BIASED TO A FIRST POSITION PROTRUDING INTO THE THROAT AND BEING EACH MOVABLE TO A SECOND POSITION FULLY RECESSED BEYOND SAID THROAT; A VERTICALLY RECIPROCABLE ABUTMENT MEMBER MOUNTED ON SAID PLATES ABOVE SAID JAW, SAID ABUTMENT MEMBER BEING IN A LOCATION BRIDGING SAID THROAT; MOTION LIMITING MEANS OPERATIVELY CONNECTED BETWEEN SAID ABUTMENT MEANS AND SAID PLATE TO LIMIT THE EXTENT OF DOWNWARD MOTION OF SAID ABUTMENT MEMBER REALTIVE TO SAID PLATES; LIFTING MEANS OPERATIVELY CONNECTED BETWEEN SAID ABUTMENT MEMBER AND SAID JAWS TO CAUSE SAID JAWS TO BE MOVED TO THEIR SECOND POSITIONS IN RESPONSE TO PREDETERMINED UPWARD MOTION OF SAID ABUTMENT MEMBER RELATIVE TO SAID PLATES; LATCH MEANS ON SAID JAWS AND SAID PLATES ENGAGEABLE WHEN SAID JAWS ATTAIN THEIR SECOND POSITIONS TO SELECTIVELY PREVENT MOTION OF SAID JAWS RELATIVE TO SAID PLATES; AND MEANS ON SAID JAWS ABUTMENT MEMBER OPERATIVELY ENGAGEABLE WITH SAID LATCH MEANS TO RELEASE SAID LATCH MEANS WHEN SAID ABUTMENT MEMBER IS IN ITS LOWERMOST POSITION RELATIVE TO SAID PLATES AND ALLOW SAID JAWS TO RETURN TO THEIR FIRST POSITIONS.