GB1206043A - Improvements in or relating to projectors - Google Patents

Abstract

1,206,043. Projector. RANK ORGANISATION Ltd. Jan.1, 1969 [Feb.9, 1968], No.6553/68. Heading G2E. A projector has horizontal takeup and feed spools mounted one above the other with guide means for twisting the film between the two spools. As shown, the projector comprises a casing 1 containing a conventional projection system with horizontaly co-axially mounted feed spool 8 and takeup spool 9. Film 7 from reel 8 is fed above the top 11 of casing 1 over guide rollers 10, 10<SP>1</SP> to an opening 12 in the casing 1 from where it passes through the gate 5, over guide roller 13 to takeup spool 9, the periphery of which, directly rearward of the gate 5, rotates away from the gate. Automatic threading means may be provided Fig.2 (not shown) which includes a hollow guide chute (16) and retaining finger (21) serving to twist and divert the film end through 90 degrees after leaving the gate, so that if may be engaged by radially projecting hooks, (24) on the hub (23) of spool 9. Alternatively, for manual threading an additional roller may be provided. A fixed strip 15 around the feed spool 8 retains film which unwinds from the supply spool 8. Spool Drive Spools 8 and 9 are supported on a spindle 26, Fig. 3, mounted in fixed bearings 27 between which pulley 28 is rigidly secured to the spindle, the pulley being driven by belt 28<SP>1</SP> from a motor. The pulley 28 and hence spindle 26 is supported on a lifting arm 29 pivotally mounted at one end 32 and supported at its other end by a slidable cam 33. At the lower end of spindle 26 is a clutch plate 34 upon which the spool 9 rests, thus a constant frictional drive is applied to spool 9. Supply spool 8 has a hub 36 arranged to rotate on spindle 26 and including a housing 37 for a dog clutch. Below and coupled to housing 37 is a clutch plate housing 38 formed on its upper surface with a dog clutch slot 39. On its lower surface a bearing surface 42 is arranged to run on the upper bearing 27. Rigidly secured to spinle 26 within housing 37 are dogs 43 and rigidly secured to spindle 26 within housing 38 is a clutch plate 44. In operation, when projecting, the lifting arm 29 is in its upper position (dashed line) so that the dog clutch is disengaged and clutch plate 44 engages housing 38. A torque is therefore applied to the supply spool 8 which opposes the intermittent feed mechanism and maintains the film strip taut. At the same time, clutch plate 34 exerts a torque on takeup spool 9 sufficient for the film to be wound with adequate tightness. For rewind the cam 33 is withdrawn to the right allowing spindle 26 to fall to engage the dog clutch, the drive being against the torque exerted by clutch plate 34 on takeup spool 9 to avoid "snatching" of the filmstrip