The Film Daily (1929)

THE DAILY Wednesday, April 17, 1929 13th Instalment, 'Sound Patent' Series ARTICLES SCHEDULED TO RUN WELMNTO SUMNER This is the thirteenth instalment in "Sound Patents," a series of articles dealing with the patent history of sound and synchronization devices in the United States, England, France and Germany. Instead of positively coupling the projection machine and the phonograph so that they are driven at the same relative speeds at all tim,es, the inventions of certain patents have relied on the operator of one machine, usually the projection machine, to run the machine at the speed of the other, usually the phonograph, which should in any event he run at a constant speed. In such arrangements, the driving means for each machine is entirely independent of the driving m,eans of the other but the speed or progress of the machbie that sets the pace is signaled to the operator of the other so that he nmy speed up or retar'd the machine under his control to synchronize it with the former. An early example of this type of apparatus is shown in Fig. 1 of a British patent No. 413 to Oskar Messter, issued Sept. 21, 1905. In this apparatus, a contact (f) on a gear (d) of the phonograp!; driving mechanism, located back of the screen, contacts with a fixed contact (g) at each rotation of the gear (d) and temporarily closes a circuit through yz^<^ a bell or gong (h) located adjacent the projection machine(b). The gear (d) is so proportioned that the bell (h) is struck once for each revolution of tlie projection machine crank and preferably when the crank completes its down stroke. By turning the projection crank in time with the bell, it will be run at the same relative speed as the phonograph and synchronism between the phonograph and projection machine will be maintained. A later British patent. No. 16,728, issued to Oskar Messter on May 27, 1909, disclosed improvements on this apparatus, one in which the contact making device was located directly on the record and another in which it was driven directly from the record carrying spindle. In the form of the improvement shown in Figs. 1 and 2 of this patent, a stationary contact (j) is carried on an arm (g) extending to the center of a disc record and bears on an insulating plate (b) on the disc which carries a contact strip (d) so that the electric circuit is closed each MKSSTKICS Om^LKTK > ^i^/. rg^ //^^. Illustrating mechanism of Messter device, British Patent No. 413. Mcsxtey's improved synchronizina system. British Patent No. 16,728. time the strip (d) passes under the contact (j). In the form shown in Fig. 3, a rotatable contact (p) is rotated from the record spindle by means of bevel gears (k) and (m) and the shaft (o) and contacts with a stationary contact (i) at each rotation of the shaft (o). U .S. patent No. 939,337. issued to P. Seiler on Nov. 9, 1909, discloses an electric circuit, closed by the starting of the projection machine, to start the phonograph and thus to insure a simultaneous starting of the phonograph and prcjjection machine. As shown in the drawing of the patent, a phonograph disc t SEIltft BTnOUOHmBO PETICt roB nCTPRr HACBIKES »FD PBOHOO&irU IFtLlDttlPII mil' bcl 1. IMI 939,337. PsIeuUid Not. 0. ItM) Seller dct'ice for synchronising sound and film. U. S. Patent No. 939,337. (I) is driven from a motor (2) which is in an electric circuit through a pair of contacts (21) and (22) which may be bridged by a contact on a lever (17) to close the circuit and start the motor (2). The lever is held in raised position by a support (18), which rests on a disc (19) geared to the projection machine crank (8) through gears (5) and (6) so that when the crank (8) is turned the disc (19) is rotated, carrying the support (18) to the position sliown in dotted lines and permitting the lever (17) to drop and bridge the contacts (21) and (22). A branch circuit through an electro-magnetic ticker (7) is closed momentarily at each revolution of a rotating contact (II) driven from the record disc (1) through gears (9) and (10). thus causing a periodic sound, timed in accordance with the speed of the phonograph. A British patent No. 24,091, issued to Frank Donisthorpe on Oct. 17. 1912. also discloses a timing device on the crank of the projection machine to sound simultaneously with the phonograph timing device when the phonograph and projection machine are in synchronism. In British patent No, 26,522, issued to Alfred J. Boult on Sept. 6, 1906, which is for the same invention as U. S. patent No. 839,152, issued to H. Joly on Dec. 25. 1906. a dial is rotated by the projection machine and a hand in front of the dial is rotated by the phonograjdi in such a manner that when the phonograph and projection machine are run at their proper speeds relative to each other, the dial and hand rotate at the same speed and the hand points to a mark on the dial. In the apparatus of Figs. 1 and 2 of the patent, the dial (q) having a mark (s) is driven from a projection machine (b) by means of a flexible shaft (c) and a worm and gear (v and u). The pointer (r) mounted on a shaft (o) rotatably extending through the dial is driven by an electric escapement, shown in Figs. 3 and 4., comprising a pivoted lever (i) positioned to be intermittently rocked by the periodic energizing and de-energizing of electro-magnets (g). Such escapements are common or standard devices for advancing a hand a definite angle with each making and breaking of a circuit through the electro-magnets or solenoids. The circuit through the solenoids (g) is opened and closed by a cam (e) on the shaft of the phonograph between a pair of contacts (d) of a circuit through the solenoids, thus insuring an opening and closing, or making and breaking of the solenoid circuit with each half revolution of the phonograph shaft. An electric starting or releasing device for the phonograph under the control of the operator is provided adjacent the projection machine. Controlling synchron\ via dial is a feature of Bimlt's apparatus. British Patent No. 26,522. Photophone For Denver Orpheum Denver — The Orpheum has been equipped with RCA-Photophone sound equipment and inaugurated its first sound program yesterd ly with "Love in the Desert." Springfield House Wired Springfield, 111. — RCA Photophone ec|uipment has been installed at the Orpheum. Port Jefferson House Wired Port Jefferson, N. Y. — Western Electric equipment has been installed at the Huntington.