US2000698A

US2000698A - Motion picture apparatus

Info

Publication number: US2000698A
Application number: US437372A
Authority: US
Inventors: Clinton R Hanna
Original assignee: Westinghouse Electric Corp
Current assignee: Westinghouse Electric Corp
Priority date: 1930-03-20
Filing date: 1930-03-20
Publication date: 1935-05-07
Anticipated expiration: 1952-05-07

Description

May 7, 1935.

c. R. HANNA 2,000,698

MOTION PICTURE APPARATUS Filed March 20, 1930 4a 2 EE 2'2 9 25 a7 5 24 1 E Q I 86 295'? Sfur'f .57130 INVENTOR CY/hfD/IE/Vdflfld.

- AT'TORNEY Patented 7, 1935 UNITED STATES PATENT OFFICE 2,000,898 MOTION PICTURE APPARATUS Clinton R. Hanna, Pittsburgh, Pa., assignor to Westinghouse Electric & Manufacturing Company, a corporation of Pennsylvania Application March 20, 1930, Serial No. 437,372

2 Claims. (01. 242-57) My invention relates to motion-picture apparatus and has particular relation to automatic stopping devices therefor.

The general principle of controlling a stopping 4 5 device by the condition of a film-strip is not new in the art. However, contrivances of this nature, made according to the teachings of the prior art, with which I am familiar, have been designed to accomplish an entirely diiferent purpose than the device hereinafter described.

In devising the older contrlvances, fire prevention was the principal consideration of the inventor, while my device is designed chiefly for the purpose of facilitating the operation of an automatic threading device set forth in detail in a copending application of E. W. Reynolds, Serial No, 438,552, filed March 17, 1930, and assigned to Westinghouse Electric is Manufacturing Company, although it acts as a safety device, as well as a result of its distinct raison d'etre my invention must conform to certain requirements which are not imposed upon devices constructed according to the teachings of the prior art. Since the threading mechanism depends on the coaction of the end of a film that has been proiected and the leader of a succeeding film, the stopping device must interrupt the action of the machine at the instant when the last layer of film leaves the feeding reel. The machine must, furthermore, be completely at rest before the filmend passes through the feeding sprocket, and, since thefilm moves at a speed of from 24 ft. per minute to 90 ft. per minute, depending on-the particular machine in which it is used, the device, to be universally applicable, must respond instantaneously to a change in a property of the film, such as tension or velocity, between the reel and the feeding sprocket, involved in the stopping device.

0n the other hand, by reason of the high sensitivity of the device, thus necessitated by the existing state of aifairs in the motion-picture apparatus with which it is associated, it responds instantly to a requisite change in the effective property of the film-strip between the reel and the sprocket. Hence, the device must be designed in such manner that the film between the feeding reel and the feeding sprocket remains unchanged. with respect to the particular property involving the stopping device, during the entire projection of a reel.

It is, accordingly, an object of my invention to provide an automatic stopping device for a mo- H tion-plcture machine that shall respond instantaneously to an alteration in a certain property of a section of a film-strip disposed in the machine.

Another object of my invention is to provide means for causing the property of the film which is responsive to remain constant in the region 5 affecting my device during the entire projection of a film-strip.

Still another object of my invention is to provide a system whereby a motion-picture machine may be stopped by the action of any one of a lo plurality of mechanisms at a plurality of points, and started by the action of one, and only one mechanism.

More specifically stated, it is an object of my invention to provide a power-supply network for is a motion-picture machine, wherein a plurality of contacts are disposed, certain of said contacts being held in closed position by the instantaneous coaction of the film, disposed in the apparatus, with certain others of said contacts and being 20 opened independently either by the instantaneous action of the remainder of said contacts or by the instantaneous action of the film.

According to my invention, I provide a sleeve concentric with the feeding spindle of a motion- 25 picture machine and positively actuated by the tension of the film, through a friction clutch, to close a contact, thus providing a permanent path for the energizing current of a relay that has been initially excited by the temporary completion of 30 an auxiliary circuit. I furthermore provide an additional contact in the permanent circuit of the relay for manually opening this circuit.

The novel features that I consider characteristic of my invention are set forth with particular- 85 ity in the appended claims. The invention itself, however, both as to its organization and its method of operation together with additional objects and advantages thereof, will best be understood from the following description of a specific 40 embodiment, when read in connection with the accompanying drawing in which:

Fig. 1 is a view, partially in section taken along line I--I of Fig. 2 and partially in front elevation of a section of a motion-picture machine wherein the mechanical elements of my invention are embodied and shows, in addition, a schematic representation of the electrical network included in the device.

Fig. 2 is a view, in section, taken along line IIII of Fig. 1, showing, in addition, the hubs of the reels embodied in the machine.

Fig. 3 is a view, in elevation, of the bottom of the machine, showing the wiring system.

The mechanical elements of my device are in part discussed in the above-mentioned copending application of Reynolds. Essentia ly, they comprise a feeding reel i driven by the tension exerted by a mm 2 that unwinds therefrom, bushing 3, of T form in longitudinal section, driven by the reel E and fastened to it by a key t with which the stem is provided, and a bushing of reversed E form in longitudinal-section, frictionally driven by the bushing 3 and coacting with a plura ity of resiliently mounted contacts I, as will be explained hereinafter. The Z is advanced by a sprocket wheel Ill suitably disposed in the filmhandling machine of which the feeding reel E is an element.

The flange of the T section is urged to yieldingly engage a washer ti fastened to the rim of the section 8 by a spring 2 compressed between its stem l3 and the washer. A dielectric prism 14, having a rectangular channel 5 milled in its apex and a cylindrical channel it milled on its base, is rigidly fastened to the section bushing 6 and rotates therewith as the former is rotated through the friction coupling between the T- fiange S and the washer ii. The rectangular edges of the slot 55 in the prism |6 engage a plurality of flexible metallic strips ll, mounted on an insulator i8, and resiliently urge the studs fastened thereto to make contact with each other. A stop i9 is provided to prevent the springs H from being excessively deflected.

The electrical equipment of my invention is shown schematically in Fig. l and comprises a switch provided with a plurality of

poles

22 and 23 and 2d and a plurality of

movable contacts

25 and 26 and a relay 2| equipped with a plurality of movable contacts 21 and 28 and a plurality of stationary contacts 29 and 3|.

The switch is actuated through an arm 33 of a hell-crank lever 34 pivotally mounted on a pin 3-5 fastened to the switch-supporting panel 36 and provided, near the end of its remaining arm 31, with a flange 38 that coacts with a plurality of flat springs 39 supporting the

movable contacts

25 and 26.

Normally, one set of poles and

contacts

23 and 26 are in closed position while the

remaining sets

22 and 25 are in open position. When the machine is at rest, the contacts I, operated by the feeding reel, are not closed, and the relay 2| is not energized. To start the machine, the operating lever is moved in the direction of the legend Start on the panel. The open contact 25 is thus closed, permitting a current to flow therethrough to energize the relay 2| and to heat to incandescence the filament of a sound-exciting lamp 4|,

When the relay 2| is excited, a movable contact 21 thereof closes the circuit wherein the motor 42 that drives the apparatus and the picture projection lamp 43 are disposed in parallel. The film-advancing mechanisms such as the sprocket wheel located in the apparatus are thus actuated and, in turn, advance the film through the machine to cause the feeding reel l, by its rotation, to close the contacts I associated therewith. As the lower contacts 28 on the relay 2| were closed when it was initially excited, a second conducting path is thus provided through the film-actuated contacts I through the lower relay contacts 28 and 3| and through the normally closed

switch contacts

23 and 26, whereby the -.relay 2| is retained in a state of excitation when the normally open switch contact 25 automatically returns to its initial position.

accuses After the film has been advanced through the film handling apparatus, it is wound on a. takeup reel 80 keyed to the shaft 90 on which the feed reel is mounted and driven from a pulley 85 that is suitably energized from the motor 42.

However, when the last layer of film 2 is removed from the reel it ceases to rotate, and the contacts associated therewith are opened, deenergizing the relay 2| and stopping the machine. The relay is provided with stops 45 that prevent the upper movable contact 21 from completing a circuit through the lower stationary contacts 3i.

Furthermore, the second circuit may be broken at any time during its operation by moving the operating lever 33 in the direction of the legend Stop on the switch panel. The machine might thus be instantly stopped should an occasion for interrupting its motion arise.

Ln Fig. 3, the actual wiring of the apparatus is shown. A wire 46, traversing a dielectric tube 41 in the base 48 of the machine, connects a terminal of the transformer, (not shown) that feeds the sound lamp 4| and relay 2|, to a terminal 24 of the switch. Another wire 48 is connected to the normally open contact 22 of the switch and passes up through an opening in the base 49 to the sound lamp 4| and relay 2| while a third wire 5| connected to the normallyclosed contact 23 of the switch passes up through another opening in the base and makes contact with a reel-actuated spring H.

A lead 52 from the power supply coming in through the dielectric tube 41 passes up through the base 48 and makes contact with a terminal of the picture-projection lamp 43. The other terminal of the lamp is connected to one terminal of the motor by a second lead 53.

A conductor 54 from a resistor, (not shown) used in connection with the motor, and a second conductor 55 from a terminal of the motor are connected to the power-supply lead. The remaining power-supply path of the lamp and the motor comprises a conducting lead 56 from the motor to an upper stationary relay contact 29, and a lead 51 from the remaining upper contact 29 that passes through the insulated tube 41 to the power supply.

Of the remaining leads shown, one, 58, provides a conducting path from the motor-resistor to the motor and the other provides the return path to the power-supply transformer. The return conducting path 59 from the film-operated contacts 1 to the lower relay contacts 3|, and the lead I from the other lower relay contact 3| to the sound lamp 4| and relay coil 62 are above the base 48 and are consequently not shown in Fig. 3.

Although I have shown a, certain specific embodiment of my invention, I am fully aware that many modifications thereof are possible. I may, in particular, dispense with the starting switch and relay and initiate the action of the apparatus directly from the contacts.

My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims. g

I claim as my invention: 7

1. In combination in film-handling apparatus, means for advancing a film strip, means for energizing said advancing means, a normally open circuit and means for temporarily closing said circuit for temporarily bringing said energizing means into cooperative relationship with said advancing means, means to be rotated by said filmstrip when it is advanced and means having only frictional engagement with said film-rotated cuit for the relay device including a switching means to be actuated by said film-rotated means device to be actuated to close said circuit by the when and as long as it is rotated to close said nlm only when it is being advanced by said filmcircuit and thereby to maintain said tllm-adadvancing means and means to be manually ops vancing mechanisms in energized condition to eratedtocooperate with said power supply means 5 vance said film-strip. for momentarily energizing said advancing means In film-handling apparatus means for adto advance said film strip thereby to close said vancing a film strip, means, including a relay delock-in circuit to maintain said film-strip in mavice provided with contacts. for supplying power tion. 10 to energize said advancing means, a lock-in cir- CLINTON R. HANNA. 10