Patent GB-240404-A (GB)
Title: Improvements in synchronous driving systems
IPC: G03B31/00
Filed: 1925-02-06
Abstract: 240,404. Kellum, O. E., and Murdock, S. A. Sept. 29, 1924, [Convention date]. Combined working of gramophones with kinematographs. - Relates to systems for driving two or more machines synchronously, and particularly to the driving of a kinematograph under the control of a gramophone. Two systems are described, in each of which an impulse - actuated motor drives a kinematograph, the impulses, delivered under the control of a gramophone, occurring at regular intervals corresponding with the periodic movements of the kinematograph. In one arrangement, Figs. 1, 5 and 8, a solenoid motor is used, the solenoids (of which eight are provided in the apparatus shown) being mounted in pairs in separate frames 10 of magnetic metal. The plungers 11 are connected in pairs by yokes 12, guided in slots in the frames 10, each yoke embracing one of a set of rollers 16. These are mounted on two crank pins 17, 18 of a crankshaft 19 which is geared to the drive shaft of the projector, not shown. The axes of solenoids 1, 3, 5, 7 are inclined at 45‹ to those of the solenoids 2, 4, 6, 8, and the arrangement is such that impulses are sent through the solenoids 1 - - 8 in the order of numbering. Thus, with this construction, eight driving impulses occur during one revolution of the drive shaft of the kinematograph, sixteen projection exposures usually occurring in this period. The impulses are sent to the solenoids by means of a commutator driven by the gramophone, and comprising a drum having eight segments S<1> .. S<8>. The segments are wired through collector rings and brushes (not shown) to the solenoids, one end of which is also connected to the power wire 67. The other power wire 66 leads to a set of brushes 63, 64, adjustably mounted on a conducting arm 65, and bearing on the commutator segments. The brushes are so arranged that there are always at least two solenoids in action, and three during a great part of the time. An insulated brush 80, also mounted on the arm 65, bears on the commutator in advance of the brush 64, and is connected to a condenser 70. This is also connected to the positive feed wire 66, and to the electrodes of a water or electrolyte bath 73. The electrodes are made of a metal which will cause formation of an insulating oxide coating at ordinary line voltage, the insulating coating breaking down to discharge the condenser each time a solenoid circuit is broken. Fig. 9 shows an arrangement wherein a rotary motor of ordinary type drives the kinematograph. The gramophone, driven by any suitable means, operates a rotary interrupter 82 comprising an arm 84 moving over segments 85. These are wired to segments 87 of a similar interrupter 81 driven by the kinematograph, and both interrupters are included in the circuit of the motor M<1>. The arrangement is such that the motor circuit is complete only when the rotary contact arms engage corresponding segments, and the driving motor of the kinematograph is thus kept in synchronism with the gramophone, although the normal running speed of the motor M' is such that the kinematograph tends to gain on the gramophone. The interrupter 81 (which may have the same or double, the number of segments provided in the interrupter 82) is adapted to break the motor circuit at least once during each " cycle of projector operation." Reference has been directed by the Comptroller to Specifications 15981/09; 10519/13, [Class 40 (iii), Telegraphs, Electric]; 130,894; and 147,086 and 221,774, [both in Class 40 (iii), Telegraphs, Electric].