US2267844A - Synchronizing system - Google Patents

Description

Dec. 30, 1941. w. v. s'rANclL 2,267,844

SYNGHRONIZING SYSTEM Filed Feb. 17, 1940 l *v ESM l j. 4.8 44 i 3f Patented Dec. 30, 1941 .UNITED STATES PATENT OFFICE SYNCHRONIZING SYSTEM William V. Stancil,` Hollywood, Calif.

Application February 17, 1940, Serial No. 319,564

3 Claims.

The invention relates to a method and apparatus for synchronizing the speed of moving bodies and is particularly directed to obtaining a multiple speed relation between moving bodies.

While the invention in its broadest aspect is not restricted to any particular field of useI in its narrower aspect it is particularly useful in the field of sound pictures i. e., for recording or reproducing sound and motion pictures in synchronism. More particularly the invention relates to the use of a. phonograph for the sound recording and reproducing device and to the use of the phonograph to set the speed of the kinematograph i. e., camera or projector.

The standard speed of a phonograph may be taken as 8O R. P. M. and the speed of the shutter shaft of a camera or projector as twelve times that iigure or 960 R. P. M. for 16 pictures per second. An object of the invention is to obtain a desired speed ratio such as 12 between the phonograph and the kinematograph, by operating the kinematograph motor with synchronizing impulses generated at the phonograph. In other words, this speed ratio is obtained electrically, not by the use of gears at the camera andprojector as heretofore proposed.

For further details of the invention reference may be made to the drawing wherein:

Fig. 1 is a view in elevation of a sound-picture recording system according to the invention.

Fig. 2 is a plan view of the switching device on line 2-2 of Fig. 1.

Fig. 3 is a schematic wiring diagram of circuit ci Fig. 1.

Fig. 4 is a section on line 4-4 of Fig. 3.

Fig. 5 is an elevation of projector which can be used instead of the camera of Figs. l and 3.

Referring in detail to the drawing, the motion picture camera I in Fig. 1 is electrically connected by the cable 2 to a switching device 3 mounted on the turntable 4 of a phonograph. With a cutter not shown, sound may be recorded on a disk on the turntable 4 in synchronism with the photographing of motion pictures with the camera I. Camera I represents one ot the standard makes of 18 m. m. camera although other types may be employed. Camera I has n. spring motor represented at 5 to operate it. Camera I has been modified by connecting to the illm operating mechanism 'thereof a shaft 4 which turns at the same speedv as the shutter shaft, that is, one revolution per frame. Shaft 6 forms or is connected to the shaft of the motor I which is suitably supported on top ot camera I by means the - lower disk I2 which rotates with the turntable of a shelf 3 supported by a brace or bracket l 55 4 and an upper disk I3 which is held against rotation by means of arm I4. As shown in Fig. 4, disk I2 is caused to rotate with the turntable 4 by providing it with a'recess I5 to receive the centering screw I8 commonly employed to center disks such as sound record 60 on the turntable 4. The arm I4 is hollow and serves as a cover for a portion of the cable 2. Arm I4 is connected at one'end to the disk I3 by a bolt I1 and the phonograph is provided with a post I8 against which the arm I4 bears to prevent its rotation.

As shown in Fig. 4, disks I2 and I3 are provided with a sleeve I9 having a central bore to receive the center pin 2I of the turntable 4.

Sleeve I9 is xed to disk I2 while disk I3 has a sleeve bearing 22 rotatably mounted on the upper portionV of sleeve I9. Collar having set screw 5I prevents disk I3 from moving upward on sleeve I9. Surrounding the lower portion of sleeve I9 and resting on the upper surface of disk I2 is a collar 23 which serves as a support for the flange 24 on the sleeve 22.

Disk I2 carries two'concentric rings 25 and 26 to which current is led from line 21 (Fig. 3) by brushes 28 and 29 respectively carried by the disk I3. Disk I2 carries a brush 30 which is connected by wire 3| to the inner ring 25, and a brush 32 which is connected by a wire 33 to the outer ring 26. Brushes 30 and 32 as they rotate make contact with different ones of a series of contacts 34 carried on the under side of disk I3.

Brushes 30 and 32 are about 180 electrical degrees apart, that is, when brush 30 is centered under a contact No. l, as shown in Fig. 3, the center of brush 30 is midway between contacts No. 2 and 3. Also, the brushes 30 and 32 have such a width that when one of them is midway between two of the contacts 34, it straddles those contacts. With brushes 30 and 32 in position as shown in Fig. 3, the full voltage is applied across terminals 1 3, also across terminals 1 2, so that the windings of armature 3B between terminals l3, also l--2 are energized. When disk I3 rotates 60 electrical degrees in a clockwise direction from the position shown in Fig. 3, brush 30 straddles contacts No. 1 and 3 while brush 32 is centered over a terminal No. 2. The full voltage is then applied across terminals 2 3, also 2-1, to energize the windings of armature BE accordingly. The polarity of armature 36 thus rotates as disk i3 rotates. The switching device f 3 is in eiect a commutator which determines I take out the leads 3l, 38, and 39 at three equallyspaced points marked 1, 2, and 3. The leads 8i, 38, and 39 are connected to the corresponding contacts in one oi the twelve groups which makeV up the total array of contacts S6, and the corresponding contacts in each group are connected in multiple as shown. The camera motor i' makes one revolution each time that the disk i2 rotates 360 electrical degrees and this occurs once for each group of contacts 3d and 12 times for each revolution of turntable l. y

Line 2i and iield 35 may be supplied with 24 volts from a transformer it v connected to a power lineal supplying 110 volts. Motor i may operate on 110 volts or on any other suitable voltage.

Variations inthe speed of camera motor i cannot react on and change the speed of the turntable f3 as switching device 3 does not produce a torque. Turntable l is assumed to have a speed which is sufficiently constant to be used as a factor in setting the speed of the camera. When camera i is operated, the spring motor is also operated. If spring motor E tends to drive the camera I too fast, the motor l acts as a brake. If spring motor E runs too slow, motor l supplies power to shaft 6. In both cases, the desired multiple speed relation 'isobtalined vIf desired, the motor l may be too small to operate the camera l by itself, that is, unless the spring motor is-also operated. On the other hand, the spring motor 5 may be omitted and instead the motor l built into the camera l and of a suicient size to operate the camera by itself.

- The sound and picture recorded in synchronismvwith the apparatus of Fig. lmay be reproduced, while maintaining synchronism, by us- \ing a pick-up not shown on the disk on turntable d, and by substituting the projector l2 in Fig. 5 for the camera l. Projector ft2 illustrates a standard i6 mm. projector now on the market, having a motor 63 and a shutter shaft d6. I have modified this projector by connecting to the shaft M a motor (i5 which is like camera motor 'i or which in fact may be the same camera motor 'i'. The connections for motor 415 are the saine as the connections for camera motor l as shown in Fig. 3. Motor d5 is suitably supported at the side of projector 32 by a cross piece it which is secured by set screws not 'shown to the hub l on the side of projector t2. Cross piece 4S carries posts it and da mechanically connected to the casing of motor d5. s

A s in Fig. 1, both motors d3 and i5 are operated when the projector d2 is operated. Motor d5 acts as a brake, or supplies power, depending upon whether motor a3 tends to run too fast or ltoo slow. I may dispense with motor. 45 and modify the windings of the usual projector motor d3 as illustrated in Fig. 3 for the camera motor i.

It will be apparent that I have provided avery graph having a shaft operable at another speed,

a motor for said shaft, a plurality of spaced windings for said motor, an A.v C. eld winding therefor, an A. C. line, and means comprising a commutator unit removably carried by said turnl table for distributing alternating current from said line and connections for said commutator for repeating said current distribution a number of times for each revolution of said turntable.

2. in a synchronizing system for operating e kinematograph shaft at a speed which is a multi ple of the speed of a phonograph and whereintht` kinematograph 'is provided with an A. C. motor having spaced windings and a field member, means for distributing current from anA. C. line to said windings comprising a commutator unit having a base to rest on a phonograph record and an aperture to receive the phonograph spindle, said commutator comprising one member rotatable with the turntable and another stationary member, a circular array of contacts in one plane for said spaced windings on one of said members, multiple connections for said contacts on the other side of said last mentioned member, and brushes on the other of said members. 4

3. An adapter unit for synchronizing a, kinematograph having a shutter shaft with a phonograph having a spindle. said adapter comprising an auxiliary A. C. motor 'having a plurality of spaced windings, a eld member therefor and a shaft, meansfor removably supporting said motor on said kinematograph with said motor shaft directly coupled to said shutter shaft, a single synchronizing commutator comprising relatively rotatable parts having a central bore to removably receive the end of the phonograph spindle, synchronizing connections from said commutator to said spaced windings, and means for connecting said commutator and said motor to an A. C.

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