Patent GB-132293-A (GB)
IPC: G03B21/18
Abstract: 132,293. Geyer, R. M. June 12, 1918. Kinematograph apparatus.-Safety apparatus comprises electrically-operated means whereby a safety shutter is normally locked in position to obscure the projecting-rays until unlocked automatically on a predetermined speed being reached. A second shutter is provided which must be closed before the safety shutter can be opened, the movement of both being controlled by mechanism ensuring operation in this order. Means are also provided whereby the hall lights are switched off when the apparatus is working satisfactorily, and switched on when a stoppage occurs. A third shutter is provided for obscuring the lens just prior to the termination of a film. In Fig. 16, the arrangement of the various circuits is shown, the motor and projecting circuit including the motor 2, a rheostat 3, and a normally-open hand-operated switch 4. Two shunts are included in this circuit, viz.. (1) the motor and the rheostat together with switches 6, 7, 8; (2) a governor-operated switch 9 and a magnet 10. The lighting-circuit includes the hall lamps 14 and switches 12, 13. Prior to starting, the switches 12, 13 are closed. the switches 4, 6, 9 are open, the safety and lens shutters are closed, the intermediate shutter is open, and the lamtern light on. On starting, the switch 4 is closed, and, as the speed increases, the governor-operated switch 9 is closed, thereby energizing the magnet 10, which closes the switch 6, opens the switch 13 controlling the hall lights, and releases the catch preventing the operation of the safety shutter. The mechanism controlling the switches 6, 13 is shown in Figs. 9 and 10, wherein the energization of the magnet 10 rocks a spring-controlled lever 66 which normally holds a weighted lever 71 in the position shown in full lines. Movement of this lever to the dotted-line position, when released by the lever 66, rocks, through a link 73, a bell-crank lever 74 bearing at one end a rod 79 normally holding a weighted lever 80 in the position shown in Fig. 9. Pins 82, 83 on the lever 80 are situated below pins 87, 89 on pivoted arms 86, 88 carrying the switches 13, 6, so that on the fall of the lever 80 due to its weight 84, the switch 6 is closed and the switch 13 opened. Carried by the other arm of the lever 74 are two pins 77, 78 the second of which, on the movement of the lever due to the energization of the magnet. strikes a cranked rod 37, Fig. 2, to rock a shaft 35 to remove the latch 34 from above the arm 26 of the safety shutter 20, which is pivoted on one side of a screen 21, the intermediate shutter, formed of two oppositely sliding members, being situated on the other. A spring 28 tends to retain the shutter in the closed position, and a weight 39 tends to return the catch to the operative position. To open the safety shutter, a handoperated bell-crank lever 52, mounted on a shaft 46 is rocked after being freed from a latch 59, a roller 54 thereon moving the shutter to the open position, as shown in dotted lines, through a lever 32 and a link 31. Simultaneously, the sliding members 44, 45 of the intermediate shutter are closed by a spring 55 when a pin 51 on the lever 52 is removed from below an arm 50 of a threearmed lever 47 carried by the shaft 46, the other arms bearings pins 48 engaging slots in the shutter members. After this operation is completed, the lever 52 is returned to its original position and the intermediate shutter opened. The switches 7, 12 are carried by levers so arranged that the switch 7 can be opened without opening the switch 12, but movement of the latter switch opens the former as well. Two levers controlled by the movement of the film are provided to operate these switches, one being mounted in the gate, and the other supported by the film below the gate. A stoppage of the film due to breakage below the gate opens the switch 7, thus breaking the motor circuit and causing the governor switch to de-energize the magnet 10 to close the safety shutter and switch on the hall lights. Where the stoppage of the film is due to torn film perforations, both switches 7. 12 are opened and the motor stopped, but the hall lights are not switched on. Other continsencies in which the safety apparatus is operated are set out in the Specification.