Patent GB-562120-A (GB)
Title: Improvements in control apparatus for cinematographic machines
IPC: G03B15/08
Filed: 1943-03-10
Abstract: 562,120. Kinematograph apparatus. TECHNICOLOR MOTION PICTURE CORPORATION. March 10, 1943, No. 3904. Convention date, Aug. 21, 1942. [Class 97 (i)] Means for closing or opening a shutter to produce fade-out or fadein effects comprises a shutter actuator detachably mounted on a power-driven reciprocatable carriage, movements of the carriage being determined by a controller, pre-set by hand, and being initiated by closure of a film-controlled switch ; the driving mechanism for the carriage includes a clutch engaged by energization of an electromagnet, reversing gear positioned by the controller and a detent moved by the actuator to release the controller so that a spring restores it to neutral position in which the reversing gear is disengaged and the electromagnet is de-energized. Fig. 8 shows electrical connections between a controller K, a film-controlled switch 80 and an electromagnet 50. The controller is first moved by hand on its pivot 31 to engage the reversing gear as desired and to close either a switch 73 or a switch 74; when a roller 82 falls into a film notch 84, the switch 80 is temporarily closed to complete the circuit of the magnet 50, thus closing a switch 45 which maintains the magnet circuit until the detent releases the controller K. As shown in plan in Fig. 1, the switches 73, 74 are closed by engagement of a projection 70 on the controller K with plungers 71, 72, the switch 45 is closed by a plunger 44 engaged by a pin 43 on a clutch fork 40 pivoted at 41 and linked to the armature 49 of the electromagnet 50, and the controller K is moved by a handle 54. The controller carries a detent in the form of a spring-pressed plunger 57, Fig. 7, engageable, in pre-set position of the controller, with either of two holes 58, 59 each containing a free ball 63 and formed in a fixed plate 60. The shutter actuator A is reciprocated between the full line and broken line positions shown, and is formed with shoulders 68, 69, alternatively engaging and moving, at the end of opposite strokes, a lug 67 on a slidable member 64 formed with a cam 66 shaped to raise either of the balls 63 ; the detent 57 is thus raised from the hole in which it has been pre-set, and permits spring- actuated movement of the controller K to neutral position. The controller K also carries a roller 30, Fig. 5, engaged between collars secured to a gear 24 slidable on a shaft 23 against the action of opposed springs. In the neutral position of the controller, the gear 24 is between, and disengaged from both of, two axially spaced gears 19, 21 respectively carried by shafts 18, 22 ; in one pre-set position of the controller, the gear 24 engages the gear 19 to transmit drive from the shaft 23 to the shaft 18 ; in the other pre-set position, the gear 24 engages the gear 21, which is permanently meshed to a gear 20 on the shaft 18 and thus drives this shaft in the reverse direction. One of the aforesaid opposed springs returns the gear 24, and thus the controller K, to neutral position when the detent 57 is freed. The shaft 23 is itself driven through meshed gears from a power shaft 39 when the energized magnet 50 holds the fork 40 in a position to engage a movable clutch member 38 with a clutch member 33. The shaft 18 drives, through worm gearing, a cross shaft carrying a ratchet wheel engaged with a rack extending along the bottom edge of a slidable carriage C, Fig. 5, the actuator A being detachably mounted on the carriage by means of dowel pins 14, Fig. 7, and a threaded pin 13, each extending from the carriage through the actuator ; a fly nut on the pin 13 secures the actuator. The actuator has a tapered operative end extending between rollers 7, 8 respectively carried by vertically movable slides 10, 9, Fig. 1, connected together by a tensioned spring, and each connected to one of two shutters which open from, or close towards, the centre of an aperture in the path of the light beam of the apparatus, as the actuator moves between the rollers 7, 8. The actuator is replaceable by any of others having different degrees of taper, different forms of tapering edges and differently spaced shoulders 68, 69, these differences permitting variation of the character of the fade-out &c. A handle'86 on a crank disc carried by the shaft 22 permits the starting position of the actuator to be set as desired. Specifications 536,463 and 543,113 are referred to.