Patent GB-345232-A (GB)
Title: Improvements in or relating to moving picture apparatus
IPC: G03B21/32
Filed: 1929-12-05
Abstract: 345,232. Kinematograph projection apparatus. VISIONTONE TALKING PICTURES, Ltd., St. Lawrence House, Trump Street, King Street, London. Dec. 5, 1929, No. 37385. Convention date, Dec. 6, 1928. [Class 97 (i).] A vertical panel 2 carries a film gate, spools 4, 6 on each side of the gate, and sprockets 28, 32, 30 between the spools and gate, the shafts of the sprockets being perpendicular to the panel and being driven by gearing in a casing 14 behind the panel and comprising an oil sump; means for rewinding may be provided. The mechanism is driven by a motor through a belt 202, Fig. 8, and a pulley 198 on a shaft 204. The shaft 204 is connected by a clutch 220, controllable by a lever, to a shaft 46 driving the sprockets ; it is also connected by worm gearing to a shaft 206 which drives the take-up spool 6 through pulleys 212, 216, a belt 214, and a shaft 218, and is connected by a crossed belt 226 to a pulley 228, loose on the shaft 230 of the feed spool 4, and capable of being connected thereto by a clutch 232 having an element movable, through a lever 250 and link 252, by a sliding rod 234. The shaft 206 may carry a gramophone turntable 210. When rewinding is to be effected the film is removed from the sprockets and passed over a roller 26, Fig. 1, and the clutch 232 is engaged. The spool 4 is driven in a direction such that it winds the film, and the driving effort applied to the spool 6 in its normal direction maintains tension on the film, the belt 214 being such that it slips easily over the pulleys. The shaft 46 carries a pinion 48 geared through trains 42, 44 to the shafts 34, 36 of the sprockets 28, 30, and a pinion 116, thus driven, picks up oil from the sump 120 and feeds it to the other gears. The pinion 116 is carried by a shaft rotatable by an external knob 112 so that the positions of the sprockets may be adjusted by hand to facilitate film threading. The intermittent sprocket 32 is driven from the shaft 46 by a maltese cross mechanism comprising a pin wheel 50, Fig. 5, on the shaft 46, having a locking flange 80 partly cut away, and provided with an arcuate spring 86 secured at its ends and carrying a pin provided with a roller 84 engaging the cross 52. The maltese cross mechanism is housed in a casing 58 packed with graphite or other lubricant, the casing 58 being contained in the casing 14 so that the casing 14 receives any leakage of graphite &c. Pairs of pressure rollers carried by pivoted arms 92 cooperate with each sprocket, and the pivot pins 94 of the arms carry fingers 96, Fig. 3, engaging leaf springs 98 and cut-out parts of the bearings 102 to hold the arms positively in inoperative position, or to hold them in operative position against stops so placed that the rollers do not apply friction to the sprockets. The projection system comprises a lamp house 130 mounted on a base 12 carrying the panel, a condenser 126 housed in a recess 124 formed in the casing 14, optical elements in a pivoted carrier 18 for directing the light downwards through the film, and a projection lens 154 extending through an opening in a door 190 hinged at the bottom and enclosing the panel &c. A cooling fan 222 and an intermittent shutter 132 may be provided on the shaft 46. The door 190 engages a knob 24 on the end of the rod 234, as it is closed, so as to move the rod, thus disengaging the clutch 232, and breaking the driving connection to the spool 4. The Specification as open to inspection under Sect. 91 (3) (a) describes the optical system within the carrier 18, the gate, and a projection cabinet containing a gramophone, wireless receiver, &c. The optical system, Fig. 7 (Cancelled) comprises a prism 152 and a prism 140 having reflecting surfaces 172, 174, respectively directing the beam laterally and forwardly. All the reflecting surfaces may be silvered, and the projection beam may be reflected by a mirror 178 on to a screen 176. The gate 134 comprises a fixed casting having a film track, and spring-pressed shoes carried by the pivoted carrier 18. The cabinet, Fig. 11 (Cancelled), may comprise a gramophone turntable 242, horn 246, and compartments 238 for the projector, 248 for a wireless receiver, and 250 for film spools &c. The projection beam may be directed downwards by a prism 254 through a gate 256 and projection lens 258, and then by mirrors 260, 262, and 264, to a projection screen 266. This subject-matter does not appear in the Specification as accepted.