Motion picture film projector

Claim 1

In a motion picture film projector, a film-threading mechanism comprising in combination: a casing including in one of its outer walls a continuous slot; a baseplate stationarily mounted in the casing parallel to and behind said slotted wall; a front film guide including a film gate mounted on the base plate on one side of the slot adjacent to part of the length thereof; an upper and lower sprocket rotatably mounted on the baseplate and disposed on the opposite side of said slot; a movable plate displaceable within the casing disposed between said plate and said wall parallel thereto; a rear film guide including a film gate, film-threading means and loop-setting means mounted on the movable plate, said movable plate being displaceable on the opposite side of the slot between a loading position for inserting into the slot a length of the film to be threaded and an operating position in which said film guides define therebetween a projection slot and said threading means and loop-setting means coact with the sprockets and film in the slot to thread the film upon the sprockets and to form an upper and a lower loop in the length of the film between the two sprockets; an assembly for stopping transport of the film at a selected frame, said stop assembly including: film transport means for transporting film threaded upon said sprockets, said transport means being movable into and out of transport engagement with the film; a rotatable control shaft slidable into either one of two axial positions; a solenoid means coacting with said shaft to control the axial position thereof in accordance with the state of energization of the solenoid means; transmission means on the shaft releasably coupled to the sprockets for rotating the same; a driving means for rotating the sprocket transmission means, said driving means being coupled to the shaft in one axial position thereof and being uncoupled from the shaft in the other axial position thereof, and for driving the film transport means in either axial position of the shaft; clutch means for coupling the sprocket transmission means to the shaft, said clutch means coupling the transmission means in said one axial position and uncoupling said transmission means in said other axial position of the shaft; film transport control means moving the transport means into engagement with the film in said one axial position of the shaft and moving the transport means out of such engagement in said other axial position; control circuit menas including switches controlling an energization circuit for the solenoid means and cam means on the shaft controlling said switches in accordanCe with the angular position of the shaft, operation of said control circuit means activating said solenoid means to displace the shaft from said one axial position to said other axial position thereby moving the film transport means out of engagement with the film and uncoupling the clutch means thus stopping driving of the sprockets via the sprocket transmission means; and a rewind assembly, said assembly including: a supply reel for the film to be threaded and a take-up reel; drive means for winding the film from one reel upon the other; first transmission means drivable by the drive means for forward winding of the film from the supply reel upon the take-up reel; second transmission means drivable by the drive means for reverse winding of the film from the take-up reel upon the supply reel; clutch means having a first clutching position coupling said first transmission means to the drive means and a second clutching position coupling said second transmission means to the drive means; and clutch actuating means coacting with the clutch means for selectively moving the same into either one of said clutching positions, said actuating means being coupled with said movable plate for control by the position thereof, placement of the movable plate in the operational position operating the actuating means for moving the clutch means into the first clutching position to effect forward drive of the film and placement of the movable plate in the loading position operating the actuating means for moving the clutch means into the second clutching position to effect rewind of the film.