Patent GB-602868-A (GB)
Title: Improvements in motion picture projection machine
IPC: G03B1/42
Filed: 1944-10-09
Abstract: 602,868. Kinematograph projectors. RAMSEY, A. R. J. (Century Projector Corporation.). Oct. 9, 1944, No. 19405. [Class 97 (i)] A projector comprises a plurality of film feeding mechanisms including an intermittent feed mechanism, a film gate, a projection lens, a common mount for the lens and front gate member, and driving means for the film feeding mechanisms, the intermittent feed mechanism and the devices thereafter specified being of unit construction separately assembled in the projector. The feed sprockets 13, 108, Fig. 1, are provided with pressure rollers 10, 106 whose spindles are secured to arms 4. 103 by screws 7, 83. These arms are carried on spindles 5, 104, secured to the casing by screws 6, 114. Stripper arms 11, 111 are integral with the arms 4, 103. The member 33 secured to the casing by screws 27 carries rods 28 supporting the carriage 29 for the lens mount which is adjustable for focussing by a screw 31 with knob 32. The member 33 also carries a sliding tube 34, which supports the film gate, axially-movable by a knob 38 by means of a pin 36 engaging a slot 35. The tube 34 is prevented from rotating by a pin 40 engaging an axial slot 39. The pin 40 is made eccentric to provide for small adjustments of the tube 34 round its axis. The front member of the film gate is attached to the tube 34 by screws 78 engaging the heads of studs 74 secured to the main plate of the gate 42, Fig. 4. The shoes 48, 49 are secured by screws 50, 58 passing through the plate 42 to plates 51, 52 resiliently secured to the plate 42 by screws 54, 56a and by studs 60, 61 fixed in the plate 42, passing through the plates 50, 51 and carrying springs 70, 73 with adjusting nuts 62, 63. Secured to the plate 42 above and below the aperture 43 by screws 77, 78 are plates 66, 76 to minimise the spreading of any fire occurring in the gate. Clamped under the plate 66 is a plate 64 formed at the top with film guiding fingers 65. The rear member of the gate, separately secured to the casing comprises a support 22 which carries rollers 24 and shoes 20 with guides 21 at the sides of the film. The beam from the light source is surrounded by a casing 17. The intermittent mechanism casing 81 has a flange 84 by means of which it is secured to a panel 82. Notches 85 in the flange permit easy withdrawal. The unit has oiler 87 and inspection window 88. The intermittent sprocket 90 has film shoes 93 resiliently mounted on an arm 92 pivoted on a spindle 91. The panel 82 can be moved vertically for " framing " the film by a rack and pinion 167, 168 controlled by a knob 164, Fig. 16. The main drive to the projector is to a shaft 115 driving a vertical shaft 119. This drives the film feeding mechanisms, the upper and lower sprockets through gears 152, 156 and the intermittent feed through a gear 153. The shaft 119 also drives a gear 127 on a spindle 121 and another gear 135 on a lay shaft, which through further gearing in the casing 133 drives a tubular shaft 141, concentric with 121, which carries a second shutter rotating oppositely to the first. For adjusting the timing of the intermittent feed the gear 152 is slidable on the shaft 119 by means of a sliding carriage 173 moved by a screw thread 176a controlled by a knob 182. The shaft 119 also carries a governor 158 which lifts a fire shutter out of the light beam at a certain speed. The governor is adjustable by a screw 160.