Patent GB-677476-A (GB)
Title: Improvements in or relating to motion picture cameras
IPC: G03B15/08
Filed: 1950-04-26
Abstract: 677,476. Kinematograph cameras. REVERE CAMERA CO. April 26, 1950 [Dec. 2, 1949], No. 10269/50. Class 97 (i). The camera comprises two spool mounting means, a gate disposed at the rear of the camera in the film path between the spools, and a solid body member between the spool mounting means defining separate spool compartments, the body member also being apertured from the front of the camera to the gate, containing the lens and determining the position of the gate with respect to the lens. One embodiment is shown in perpendicular vertical sections in Figs. 5 and 7 and in horizontal section in Fig. 6. The camera structure is composed of a body member 30, a side plate 34, a front plate 35 and a hinged side door 31. The body member 30, and the plate 66 supported on columns 67 forming part of the body member, support all the mechanical and optical parts of the camera. A tapering recess 53, behind an aperture in the front plate, leads rearwardly to the objective assembled in a housing 200, screw-threaded into the member 30 for pre-set focus adjustment and secured by a set screw 205. The lens aperture is adjustable by a rotatably mounted disc 44 accessible for adjustment from the outside of the camera to bring a selected one of a number of holes of different sizes in front of the lens. The disc is carried on a member 213 secured to the member 30 and formed with a non-circular hole for engagement with a similarly shaped latch member 217 rotatable by the knob 33 to secure the hinged cover 31. The driving motor has a spring 72 contained in a drum 70 to which the outer end is secured, the inner end being secured to a hub 71 forming part of a shaft 73 rotatable by an external key 47 and having ratchet connection with the plate 66. The housing 70 carries gear teeth 84 to drive a pinion 83 on a shaft 82 which also carries a pulley 86 to drive, through a spring belt 87 and pulley 81, a tubular shaft 79 with which the take-up spool 49 is engaged. The feed spool 50 is freely rotatable on the fixed spindle 145. The shaft 82 also carries a face gear 85 which' drives a pinion 91 on a shaft 90 from which a shaft 96, on which a governor is carried, is driven by gearing 94, 95. The friction disc 102 of the governor bears on a brake shoe 105 adjustable for speed control by an external knob 46 through an eccentric 109. A film footage indicator is provided having a feeler 221 carried on a shaft 220 and normally spring- urged into contact with the film on the take-up spool. An indicator 222 carried on the shaft 220 moves behind a slotted plate 45 in the camera wall 34. When the latch member 217 is rotated by the knob 33 to release the cover 31 it also releases a wire spring 228 and allows it to bear on the follower 221 to lift it clear of the spool 49 so that the spool can be detached when the cover is open. The film proceeds directly from the feed spool to the gate and thence round a non-rotatable rubber snubbing member 143 to the take-up spool. One gate member 57 is secured to the member 30 and has upstanding edge and marginal film guiding portions and, when only half of the film is to be exposed, a central guide also. The exposure aperture 123 is formed in this member. A sideways extension 126 of this member has an embossed portion 131 which seats in a recess 132 in the camera wall and carries a bearing 130 for the shaft 90. The portion 126 also carries a pivot for the claw arm 128. The claw 134 is of the kind shaped to engage the film perforations in the direction of feed but to trail over them in the reverse direction. The claw arm has an aperture 129 in which engages a driving cam 133 on the shaft 90, which also carries the shutter 135 and a counterweight 136. The spring-urged pressure plate 58 is carried on a member 137 secured to the hinged cover 31. The operation of the camera is controlled by a vertically movable member 39 carried on a member 161 having cam surfaces to actuate a pivoted member of which the end abutment 176 co-operates with pins 92, 93 projecting from the shaft 90. Movement of the control 39 downwards moves the abutment 176 to the left, as seen in Fig. 6, to clear the pin 92 and allow the mechanism to rotate continuously. Upward movement of the control 39 moves the abutment from the path of the pin 92 into that of the pin 93 to allow the shaft to make rather more than half a revolution to effect a single exposure. A knob 40 projecting from the front of the camera controls the actuation of a vertically slidable member 152 to which is pivoted at 153 a cover 42 for the mouth of the light passage 53. The cover 42 is spring urged into contact with a cam surface on the camera wall so that downward movement of the member 152, produced by the knob 40, produces a downwards and sideways movement of the cover 42 sufficient to move it clear of the light passage 53. In a modification, the area and movement of the member 152 itself are sufficient for the member to perform this function. In a further modification the member 152 is coupled through rack-andpinion mechanism to an equally and oppositely moving member, the two members together forming a cover for the passage 53. In a still further modification the member 152 has rack-and-pinion engagement with an iris diaphragm at the mouth of the passage 153. A view-finding passage extends through the camera body and an upward extension of the member 152 projects into it to indicate the extent of opening of the passage 53. The member 161 carries an abutment which engages the member 152 so that if the control 39 is pushed down, to start continous running of the camera, when the passage is closed, the cover is opened by this movement to produce a fade-in effect. Specification 677,500 is referred to.