Patent GB-555916-A (GB)
Title: Improvements in or relating to motion picture projectors
IPC: G03B21/43
Filed: 1942-03-09
Abstract: 555,916. Kinematograph projectors. KODAK, Ltd. March 9, 1942, No. 3100. Convention date, March 14, 1941. [Class 97 (i)] Members loosely mounted on a drive shaft, and respectively operatively-connected to a film-feeding and winding mechanism and to a rewinding mechanism, are alternatively connected to, or both disconnected from, a driving member splined on the shaft, by movement of the driving member; the projection lamp circuit may be automatically controlled to permit the projection of "stills" while the driven connection is broken, and to be open during rewinding. As shown, a shaft 20 is driven, during feeding, by a motor 26 through a belt 22, and drives, through gearing 19, 18, 16, 15, and clutch housing 72, sprocket shafts 11, 12 and a take-up spool spindle 57 ; the shaft 20 also drives a feed claw and a shutter. During rewinding, the motor 26 is reversed and drives, through a belt 105, only a shaft 102, the upper spool spindle 56 being directly driven from this shaft. The motor shaft 25 carries clutch members 35, 36, Fig. 6, respectively formed on pulleys 23, 30 loose on the shaft. A clutch member 31,splined on a sleeve 49 secured to the shaft 25, is movable by a fork 42 to engage either of the members 23, 30, or to be in a neutral position and free from both ; a spring-pressed ball 37 engages one of two grooves 38, 40, to hold the clutch members in engaged position, or engages a groove 39 when in neutral position. Each clutch housing 72 comprises inner and outer sleeves 77, 78, Fig. 2, mounted on a sleeve 65 loose on the sprocket shaft, and connected to this sleeve by a friction clutch comprising a friction ring 97 carried by a disc 66 on the sleeve 65 and adjustably engaged with a circular face 73 formed in the housing 72, the engagement being effected by a spring 80, adjustable nut 96, &c. The disc 66 also carries a double pawl arm 67 forming a one-way connection with a ratchet wheel 69 secured to a sleeve 64 loose on the sprocket shaft, the one-way connections being in opposite directions for the two sprocket shafts ; a gear 63 on the sleeve 64 meshes with a gear 62 on a shaft 61 connected by gears 59, 60 to the spool spindles. The upper housing 72 is permanently connected to the sprocket shaft 11 by lugs 84 engaging openings 85 in the gear 15 keyed to the shaft, but the lower housing is detachably connected to its shaft 12 by an axially slidable collar 87 having lugs 88 passing through the openings in the gear 15 to engage lugs on the housing. The upper sleeve 64 also carries a gear 101 driven by a gear 103 on the shaft 102. Control of the drive connections is effected by a shaft 116, rotatable by a handle 120, and carrying cams 117, 115 respectively turning the fork 42 about a pivot 44, and turning a forked lever 110 about its pivot 111, and against the action of a spring 124, to move the collar 87. With the handle 120 in the position shown, the clutch element 35 is engaged by the clutch member 31 and the collar 87 secures the lower housing 72 to the sprocket shaft. Drive is effected, either forwardly or in reverse, through the belt 22 &c. to feed the film through the gate and wind it on to the take-up spool, the pay-out spool being allowed by the pawl 67 and ratchet wheel 69 to run freely. The handle 120 may be raised to free the clutch element 31 from both clutch elements 35, 36, thus breaking the drive and permitting the projection of a still image. The handle 120, when further raised, connects the clutch elements 31, 36, and the motor, running in reverse, drives through the belt 105, gears 103, 110, &c., only the upper spool for rewinding, none of the other parts of the mechanism being driven. An arm 123 on the shaft 116 may control a plunger 122 connected to a switch in the projection lamp circuit to extinguish the lamp during rewinding.