Patent GB-365304-A (GB)
Title: Improvements in or relating to motion picture machines, such as talking motion picture machines
IPC: G03B1/44
Filed: 1931-01-06
Abstract: 365,304. Kinematograph apparatus. WHITE, A. E., 5, Quality Court, Chancery Lane, London. - (Radio Corporation of America; 233, Broadway, New York, U.S.A.) Jan. 6, 1931, No. 607. [Class 97 (i).] A kinematograph machine, such as a machine adapted for use with a combined sound and picture film, comprises mechanism for threading a film through the machine and means movable to threading and operating position for automatically forming loops, co-operating with positioning means for the film during the reproduction of both the sound and the picture portions, and including manually operated means for moving the loop-forming and positioning means from operating to threading position, and means operated by the film for releasing the manually operated means. As shown in Fig. 1 film is fed successively over the sprocket 24 within the guide 40, through the upper loop guide 41, the picture gate 27, the lower loop guide 43, round the damping roller 35 and the sound drum 30, and through the sound gate 31 to the sprocket 25, whence it passes through the guide 50 and is automatically attached to the take-up spool 23. The film gate, Fig. 2, comprises two members 75, 76 fixed by the flanges 73, 74 respectively to the main frame. The movable pressure plate 77 is pressed against the member 75 by the spring 78 and carries pins 81, 81<1>. The cylinder 82 carried by the pin 83 and operated by the crank lever 84 has a slot 85 engaging the pin 81<1>, which engages the forked lever 86 carried by the rotatable shaft 87, the upper end of which has a forked lever 89 engaging the pin 81. Attached to the member 82 is the movable loop guide 44. The sound gate, Fig. 3, has a pressure plate 90 in an opening of the guide 45 surrounding the sound drum which is pressed on the film by springs 93. The lip of plate 90 presses the film 92 sidewise, against the lip 105 on the guide 45 by means of the springs 94 surrounding the pins 91, on which the bosses 96 are slidably mounted. The yoke 95 is loosely mounted in the lever 103 by a pin 102. One arm of the bent lever 101 engages the head of pin 102, the other the flange 98 on the plate 90. Movement of the lever 103 thus removes both normal and lateral pressure from the film. The take-up spool 23, Fig. 5, has a hub 125 in apertures 127 of which are plungers 126 pressed outwardly by springs 128 and retained in the hub by bushings 131. One of these pins engages a hole in the end of the film and the pins are then depressed until flush with the surface of the hub by the succeeding layer of film. The sprocket 25, Fig. 1, is driven at a uniform speed to ensure a constant feed past the sound gate by means of a device to absorb fluctuations in the drive, comprising the driven gear (not shown) attached to which is a grid 152, Fig. 6, both of which are loose on the shaft 150, the grid being attached to the projections 153 of the flywheel 26 by the springs 154. Both the flywheel 26 and the sprocket 25 are rigid on the shaft 150. The damping roller 35, Fig. 9, provided with bosses for engaging the film at the edges of the picture section, is engaged by the friction washers 164, 166, both of which are keyed to the spindle 163 and the latter of which is pressed against the roller 35 by the spring 167. The automatic release mechanism is shown in threading position in Fig. 10, the operating lever 37 being held against the lower stop 201 by one arm of the trigger 47 engaging the catch 48, the other arm resting on the sprocket 25, so that when the film reaches this sprocket the lever 37 assumes its operating position against stop 202 owing to the tension of the spring 39. On one side of the pivot 38 the lever 37 carries the pressure roller 36 and on the other the lever 206, which operates the sound gate control lever 103, pulled into pressure position by the spring 211. The upper end of the lever 103 is pivoted to the lever 214, which engages the crank 84 controlling the picture gate and the movable loop guide 44, and which also operates by lever 221 the movable guide 42. The pin 224 on the lever 37 engages an elongated slot 225 in the lever 226 pivoted at 227 and operating the movable guide 50, which is retained in position against the tension of a spring 240 by the catch 229 and stop 230. A link 231 operates the bottom guide 233 pivoted at 254, while the lower curved guide 234 pivoted at 235 is operated by the link 238 pivoted to the arm 239 of the latch 229. Accumulation of film on the take-up spool operates the latch 229 and permits the members to assume their operating positions under the influence of the spring 240.