GB758451A - Improvements in or relating to stereoscopic motion picture cameras - Google Patents

Abstract

758,451. Stereoscopic kinematography. NATIONAL RESEARCH DEVELOPMENT CORPORATION. Aug. 11, 1954 [Aug. 11, 1953], No. 22123/53. Class 97 (1). A camera comprises a casing for two camera units A, B, Fig. 1, one with its axis horizontal behind a semi-reflecting mirror 3 and one with its axis vertical to receive light reflected from the front face of the mirror, at least one of the camera units being laterally movable in the casing, film supply and take-up means 33, Fig. 3, for each camera, being fixed on the casing, the film being fed to and from the movable camera over sprockets 38, 40 fixed in the casing and sprockets 15 on the camera unit rotated at the same speed, with film loops 41, 42 between to permit movement of the camera unit, light screening means being provided . as necessary between the camera units and the casing. As shown, both camera units are laterally movable, each sliding on a rod 6, Fig. 1, and a channel-shaped bar 8, light-tightness during the movement being provided by blinds 23 attached to the unit, ; wound on spring-loaded rollers at the sides of the casing and running, in the channel of the member 8 and a channel 26. The lateral movement is effected by a lead-screw 17, the lead-screws of both units being coupled for operation by an external hand wheel to produce equal and opposite camera movements. The film gate and intermittent feed mechanism of each unit is mounted on a plate 12 carried by micrometer screws 64, the screws being coupled by gearing, not shown, for simultaneous rotation by the shaft '68 to produce lateral movement of the gate relatively to the lens axis, the mechanisms of both units being coupled to provide equal and opposite adjustments in the two units. Each unit has a separate driving motor 16, Fig. 3, but the units are coupled to provide synchronous operation by extensions of the sprocket shafts 29 coupled by gearing, not shown, outside the casing. Splined shafts are used here, as elsewhere, to maintain driving connection during lateral movement of the camera units. The shaft 29 also drives the sprocket 40 and, through a chain drive 39, the sprocket 38. The take-up spools of the magazines 33 are driven by a separate motor 34, Fig. 1. Each objective 10, Fig. 4 is mounted by a plate 45, projecting from the mount 46, secured to a slide 47 by a clamping screw 48. The slide 47 is mounted in dovetail guides on a member 50 projecting from the housing of the camera unit. The member 45 carries a channel member 62 inclined so that transverse movement of an engaging pin 51 effects focusing movement of the lens. The pin 51 is carried by a rack 53 actuated by a pinion 55 on a shaft 56, the shafts 56 of both units being driven through gearing 57, 58, Fig. 1, from a shaft 59 actuated by an external knob. Each .camera has a reflex shutter 61, Fig. 4, which reflects the light beam, during obturation, into a viewfinder as in Specifications 740,927 and 758,452.