Patent GB-496118-A (GB)
Title: Sound-reproducing cinematographic projecting apparatus
IPC: G11B7/00
Filed: 1937-04-22
Abstract: 496,118. Combined sound and picture apparatus; induction motors. OFFICE GENERAL DE LA CINEMATOGRAPHIE FRANCAISE. April 22, 1937, No. 11577. Convention date, Sept. 7, 1936. [Class 40 (ii)] [Also in Groups XX and XXXV] Sound-reproducing kinematographic projecting apparatus has the soundreading lamp, optical system and photo-electric cell slidably mounted so as to read a sound track located at either edge of a film, the objective lens of the optical system and the photoelectric cell being mounted on a carrier supported by a dovetail guiding member. The film 48 passing out of the picture projector, which is preferably of the type in which a friction roller automatically varies the size of a loop in the film to control the film tension, as described in Specification 365,057, [Group XX], is led over a curved guide 49, constituting the sound gate, sprocket 52, and roller 53 to the take-up spool. Apertures 51, 51<1>, Fig. 1, in the sound gate correspond to the position of a sound track on the right or left of a film, and an optical condenser 56<1> and lamp 54 are mounted to slide transversely in a casing 55 between limits determined by stops 70, 71 to align the light beam with either of the apertures 51, 51<1>. The objective 60 of the optical system, carrying a casing 72 housing the photo-electric cell 58<1>, is mounted on a slide 73 which may be traversed in dovetail guides in a base 74 between limits determined by a screw 75 fast in the base 74 and passing through a slot 76 in the slide, the end positions of the slide corresponding to the alignment of the objective with the apertures 51 or 511. The slide is locked in adjusted position by a cam-shaped rod 79 which may be turned to force a thrust piece 78 into binding contact with a guide face on the base 74. The socket 87 for the photo-electric cell is fitted with rubber blocks with which spring-tongues 88 on the housing 72 engage to constitute a damped suspension for the photo-electric cell. The Specification as open to inspection under Sect. 91 describes also the following subject-matter : Spool-driving mechanism. A motor driven shaft 1, Fig. 2 (Cancelled), drives by helical gears 2, 3 a shaft 4 coupled through universal joints to a clutch member 8 having dogs 9 adapted to engage in a spring - pressed slotted member 11 splined on a shaft 12 geared to one of the spools. The wheel 2 drives also a shaft 16 through reduction gearing 17-19, the shaft 16 being coupled to the shaft 28 driving the other spool by mechanism similar to that described with reference to the coupling of the shafts 4, 12. Axial movement of the shafts 4, 16 to engage either or neither of the clutches 8, 23 is effected by collars 46, 47 controlled by yokes governed by a manual cam device. Motor control system. The speed of a squirrel-cage driving motor is controlled by axial movement of a button 104, Fig. 9 (Cancelled), journalled on a screw 105, mounted on a plate 103 having rods 102 which are coupled to a solid metal ring 101 to which three conductors 100, 100<1>, 100<11> connected to three sections of the squirrel-cage are secured. The ring 101, by axial movement, wipes over resistances 95 wound on spools 94 secured to a plate 92 carried by the motor shaft 91, thus varying the resistance in circuit with the squirrel-cage sections to vary the slip. A sleeve 98 is secured to the member 92 to house the resistances and to serve as a handle for turning the motor. Means are described also for pressing the film 48 on to the guide 49 by a felt pad 50, Fig. 6 (Cancelled), mounted in a shoe 80<1> resiliently held on a cranked lever 81 which is pivoted at 83 and resiliently maintained in position by a plunger 84. The lever 81 may be swung about the pivot 83 in order to thread the film or remove the pad 50. This subject-matter does not appear in the Specification as accepted.