Motion picture projector having a single frame clutch

Claim 1

IN A MOTION PICTURE PROJECTOR INCLUDING AN APERTURE PLATE, AN UPPER SPROCKET, A LOWER SPROCKET AND A SHUTTLE FOR ADVANCING FILM PAST THE GATE, THE IMPROVEMENT COMPRISING A DRIVE SHAFT ROTATABLE CONTINUOUSLY SELECTIVELY IN EITHER DIRECTION, A WORM MOUNTED ROTATABLY ON THE SHAFT, SPROCKET DRIVING GEARS MESHING WITH THE WORM, CAM MEANS DRIVEN CONTINUOUSLY BY THE SHAFT FOR RECIPROCATING THE SHUTTLE ALONG THE APERTURE PLATE, MEANS URGING THE SHUTTLE TOWARD FEEDING ENGAGEMENT WITH FILM LYING ALONG THE APERTURE PLATE, SECOND CAM MEANS DRIVEN CONTINUOUSLY BY THE SHAFT FOR INTERMITTENTLY PERMITTING THE URGING MEANS TO MOVE THE SHUTTLE INTO FEEDING ENGAGEMENT WITH THE FILM, A FIRST CLUTCH MEMBER KEYED TO THE SHAFT, A SECOND CLUTCH MEMBER KEYED TO THE WORM, DETENT MEANS NORMALLY OPERABLE TO CONNECT THE CLUTCH MEMBERS TOGETHER, ACTUATING MEANS FOR MOVING THE DETENT MEANS TO AN INOPERATIVE POSITION AND HOLDING THE DETENT MEANS IN ITS INOPERATIVE POSITION, SHUTTLE THROWOUT MEANS OPERABLE BY THE DETENT MEANS TO HOLD THE SHUTTLE AGAINST THE ACTION OF THE URGING MEANS