Patent GB-694426-A (GB)
Title: Improvements in kinematograph apparatus
IPC: G03B31/00
Filed: 1949-10-11
Abstract: 694,426. Kinematograph apparatus. DALLARI, V. Oct. 11, 1949 [Oct. 11, 1948], No. 26027/49. Class 97 (i). [Also in Group XL (b)] The invention is narrowly limited to a form of sound film apparatus in two separate casings, one containing the picture mechanism and the other the sound mechanism. The main claim specifies details of the driving mechanism, speed governor, speed indicator and sound mechanism. The apparatus is a camera adaptable for printing and projection. As described, the sound mechanism casing forms a closure for the picture mechanism casing and, if not required, may be removed and replaced by a cover. Claw feed mechanism.-The mechanism shown in Fig. 10 is at the front end of the driving motor shaft. The shaft carries a face cam 39 and an eccentric 40 engaged by the sides 42 of an open ended parallelogram 41 of spring material, the sides 42 being bent to channel shape for stiffening. The spring 41 carries a plate 43 carrying a rearwardly projecting follower engaging the cam 39 and bent claws 44 to engage a film lying in the plane of the paper. The eccentric 40 deforms the parallelogram to produce the feed movements of the claw and the fixing screws 46 are far enough from the vertices 47 to allow the cam 39 to bend it out of the plane of the paper to produce the engaging and disengaging movements. Shutter.-The front end of the driving motor shaft also carries the adjustable shutter shown in Fig. 17. Blades 51, 56 are secured respectively to the shaft 38 and to a surrounding collar 53. The shaft is hollow and contains a shaft 50 with a pin 55 projecting through oppositely inclined helical slots 52, 54 in the shaft 38 and collar 53. A cap 60 outside the camera casing, actuated by a lever 61 and screw threaded on to a boss 59 moves the shaft 50 axially, through a ball 62 and against a spring in the hollow shaft to produce a relative rotation of the shutter blades. Governor.-The rear end of the motor shaft 38 carries the governor shown in Fig. 13. A member 63 is secured to the spindle and carries near its periphery, a T-shaped member 65 pivoted at 64. The centrifugal force on the member 65 is transmitted, through a bearing surface 66 and a ball 72 on a pin 71 to a spring blade 69 carrying a contact 70 co-operating with a fixed contact 73. The contacts are in the motor circuit and the governed speed is adjusted by a screw 68 bearing on the spring blade 69 and carrying a calibrated adjusting knob 32 which may be located by a detent in positions corresponding to commonly used speeds. Film magazine.-The rear end of the motor shaft also drives through worm and worm wheel a belt drive to a film magazine on the top of the camera. The magazine is secured by projections in the magazine engaged under catches on the camera (Fig. 18). One projection is the end of a slidable plate 78 spring- urged outwardly against another slidable plate 79 which covers the film aperture. The plates can be slid manually by projecting buttons 84, 13. After film threading the camera side is secured by a bayonet catch 89, the rotary member of which holds the plate 79 open and abutting the plate 78 to prevent removal of the magazine. Both spools in the magazine have feed indicators. An alternative magazine is described having pairs of feed and take-up spools side-by-side, the take up spools being driven from a common pulley through separate friction drives. The film from one feed spool is fed round a curved track into superposition with the other film for feeding through the apparatus when used for printing. The super. posed films return to the magazine and are separated and wound on to the separate take up spools. Speed indicator.-The motor drives a rotatory contact device with alternate conducting and insulating sectors which feed interrupted current to a solenoid to vibrate a reed in the field of a direct vision viewfinder. The reed resonates at the correct motor speed and becomes invisible. Its frequency is adjustable by a screw, similar to the screw 68 in Fig. 13. Use.-In addition to the direct vision viewfinder the apparatus includes a prism for viewing the back of the film at the gate. The associated eye-piece can be removed and replaced by a light source for projection. Similarly a light source can be applied in place of the objective and the apparatus used for contact printing, a negative and a blank film being fed in superposition from the double spool box. A sound track can be recorded at the sound head at the same time. In the light source shown in horizontal section in Fig. 16 the lamp 118 is disposed between a condenser 117 and a diffusing screen in a holder 119 used respectively for projection and printing. Either may be rendered ineffective by attaching a shield 125 alternatively in guides 123, 123<SP>1</SP> or 124, 1241. Bayonet connections are provided for attaching the lamphouse.