US1154952A - Film-fire-prevention shutter for motion-picture machines. - Google Patents

Description

1. .wELLs. FILM FIRE PREVENTION SHUTTER FOR MOTION PICTURE MACHINES.

APPLICATION FILED 001.5. 1914.

L'T. WELLS.

, mm FIRE PREVENTION saunas FOR MOTION new mcnmes.

' APPLICATION FILED 0CT.5. I9l4. 1,154,952, PatentedSept. 28, 1915.

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O I O UNITED STATES PATENT orFIoE.

JOHN T. WELLS, OF NEWPORT, KENTUCKY, ASSIGNOR TO THE EDWARDS MANUFAC- TUBING COMPANY, OF CINCINNATI, OHIO, A CORPORATION OF OHIO.

Specification of Letters Patent.

aPatented Sept. 28, 1915.

Applioationfiled October 5, 1914. Serial No. 865,181.

To all whom it may concern Be it known that I, JOHN T. WELLS, a citizen of the United States, and residing at Newport, in the county of Campbell and State of Kentucky, have invented a new and useful Improvement in Fihn-Fire-Prevention Shutters for Motion-Picture Machines, of which the following specification is a full disclosure.

My invention. relates to an improved fireprevention film-shutter for a moving picture machine, and its speed controlled operating means.

One of the objects of the invention is to produce "operating mechanism increasing the safety provision.

Therefore I have invented a mechanism, speed controlled, but not dependent upon governor actuation, friction clutch, or fluid pressure principles, but providing positive motion transmission at a selective safety speed for operating the shutter. To this end a member having speed ratio with the film travel, and preferably a film feed roll, such as the sprocket wheel, has escapement gear connection with a normally closed shutter pivot, the tension permitting the escapement at danger speeds, but rendering effective motion transmission at a predetermined safety speed. The controlling mechanism comprises pitch-mesh members, such as a tooth wheel and multi-thread worm wheel or segment wherein the angle of thread advance, the tension of the shutter closing or normalizing device, and the speed of the tooth member in ratio with the travel, are so correlated that, at danger speeds the intermesh is non-effective or of an escapement nature, while at and after a predetermined safety speed the intermesh is progressive over a given space, rendering a predetermined-dimension motion transmission, for opening and holding open the shutter, the slowing down of the film feed normalizing the shutter, under the tension influence. The fact that the critical speed opens and closes the shutter by gear-type transmission, renders the operation mechanically positive and accurate, and in my preferred form shown, the elements are few, simple and effective in operation, and readily adjustable so that the safety speed can be easily and selectively predetermined and secured.-

The features of the invention are more fully set forth in the description of the accompa'nying drawings, forming a part of this specification, in which Figure 1 is a side elevation of a film and light controlling unit of a rojecting machine, with one of the side ames removed and some of the parts in section. F g. 2 is a plan section taken on line 22, Fig. 1. Fig. 3 is a detailed section on line 3 -3, F ig. 2. Fig. 4 is a detailed plan sect1on on line 44, Fig. 1.

The unit shown intermittently feeds th film past the focal tube 1, by an intermittently operated sprocket roller 2, which may be driven by any suitable means, such as the ordinary type of Geneva gearing.

A back plate 3, having a light aperture 4, is pivotally mounted in the side frames and held in position by a bale 5 engaging the upper end thereof.

As there is always danger of the film becoming ignited, by the heat of the light rays, when it is run too slowly or stopped, I provide a fire shutter 6, which is governed by the speedof the intermittent feed roller 2. This fire shutter extends over-the full area of the light aperture 4 and is secured to an upright rod 7.,journaled in the back plate at 8, and int. bracket 9 attached thereto. A coil spring 10 surrounds the rod, one end bearing against the face of the fire shutter and the other end extending into an orifice in the back plate. Said spring is normally under tension and tends to force the fire shutter against the back plate to close the light aperture 4, said movement being made noiseless by a rubber bumper 11, secured to the fire shutter. Secured to the lower end of the rod 7, opposite the shaft of the roller 2, is a cylinder 12, having a plurality of elongated spiral teeth 13, which are adapted to be engaged with a camming action by the teeth 14 of a triangular wheel 15, to expose the light aperture 4. The wheel 15 is socured to the hub of the roller 2 by a set screw 16 to provide for lateral adjustment. In starting the machine one of the teeth 14 will engage the first spiral tooth 13 and rotate the cylinder 12 sufficiently to bring the second spiral tooth into operative alinement with the plane of travel of the teeth 14, thereby commencing the opening movement of the fire shutter.

If the next tooth 14, of the wheel 15, is brought into action with the second spiral tooth with suflicient rapidity, the rotation of the cylinder will be continued, otherwise the coil s ring 10 will act when the triangular whee 15 assumes the position shown in Fig. 3, and before the second tooth 14 has had time to engage the second s iral tooth the triangular wheel 15, the point of contact between the teeth 13 and 14 will be varied with a corresponding variation in the speed required for effecting an opening movement of the fire shutter. This positive or gearlike opening and closing of the shutter by speed control, and mechanically holdlng open solely under the influence of a safety film speed, eliminates every element of insecurity or failure of transmission at critical speeds, and'the invention obviously Involves principles of operation susceptible of varlous structural and mechanical embodiment.

Having described my invention, I claim 1. In a device of the class described, a normally closed fire-prevention shutter disposed in relation to the light exposure of the film, a rotary member havlng speed ratio with the film travel, and worm mechanism functioning under predetermined speed influence of said rotary member for operating the shutter. I

2. In a device of the class described, a normally-closed fire-prevention shutter disposed in relation to the light exposure of the film.

a rotary member having speed ratio with the film travel, and worm mechanism functioning under predetermined speed influence of said rotary member to open and hold o en the shutter at a predetermined rate of lm travel, and means positively closing the shutter when the a rate of film travel decreases 3. In a device of the class described, a firerevention shutter disposed in relation to the Elm light exposure, a rotary member having speed ratio with the film travel, normalizing means for the shutter, and coordinating pitch members rendered operative by the speed influence of said member for overcoming the normalizing tension and moving the shutter.

4. In a device of the class described, a fireprevention shutter movablydisposed in relation to the film light exposure, a shutter the and coiirdinatin itch members connecting said member an s utter and rendered operative or inoperative by the speed of said member.

5. In a device of the class described, a firepivogfial lmember movable in speed ratio with shutter for the film, means normally closing the. shutter, a member havin speed ratio with the film travel, and coiir inatin pitch members entraining theshutter wit saidfilm feed member, the itch angle being such that the shutter is he (1 closed at danger film speeds and progressively opened at safet speeds.

6. In a device of the class described, a' normally closed fire-prevention film-shutter, and operating means therefor, comprising coordinating pitch members rendering positive motion transmission ata safety film speed to open the shutter.

7. In a device of the class described, a normally closed fire-prevention film-shutter, and operating means therefor, com rising'members having a pitch-mesh ren ering a predetermined dimension motion transmission at a safety film speed to open and hold open the shutter.

8. In a device of the class described, a fireprevention film-shutter, a tension device normally closing said shutter, operating means therefor comprisin members having a pitch-mesh, the tension degree of said tension device being predetermined in relation to said pitch mesh to prevent effective motion transmission at danger film speeds, and

rendering a predetermined dimension motion transmission at a safety film speed.

9. In a device of the class described, a fireprevention film-shutter, a tension device normally closing said shutter, operating means therefor, comprisin members having a pitch-mesh, the tenslon degree of said tension device being predetermined in relation mission until a pre etermined speed of the other member ,is attained, and thereafter rendering a predetermined dimension motion transmission for opening the shutter, said tension normally holding the shutter closed.

11. In a device of the class described, a fire-prevention film-shutter, operating means comprlsing a driving and a driven pitchmeshed member, the riving member having speed ratio with the film travel, a tension device holding the shutter normally closed and influencing the said driven member to provide an escapement of effective motion transmission until a predetermined s eed of the driving member is attained, sai itch mesh being arranged to produce a pre eterefl'ective motion transtio with the film travel,

mined dimension motion transmission at a safety film speed for opening the shutter and maintaining it open while said driving member is operated at a safety film-speed.

12. In a device of the class described, a fire-prevention film-shutter, and operating means therefor, comprising a speed controlled intermeshing escapement worm-type mechanism for operating the shutter.

13. In a device of the class described, a fire-prevention film-shutter, operating means therefor, comprising a speed controlled escapement mechanism for operating the shutter, and means enabling relative adjustment of the escapement mechanism providing a selective critical film-speed for shutter operation.

14. In a device of the class described, a fire-prevention film-shutter, a pivot member therefor, a rotary member having speed rapitch-mesh members connecting said rotary and pivot members, a tension device holding the shutter normally closed and influencing said pitch mesh engagement to prevent effective motion transmission until a predetermined speed of the rotary member is attained, said pitch mesh members functioning to open the shutter at a safety film speed.

15. In a device of the class described, a fire-prevention film-shutter, a pivot member therefor, a rotary member having speed ratio with the film travel, pitch-mesh members connecting said rotary and pivot members,

atension device holding the shutter normally closed and influencing said pitch mesh engagement to prevent efiective motion transmission until a predetermined speed of the rotary member is attained, said pitchmesh members functioning to open the shutter at a safety film speed, and means providing relative adjustment determining the critical speed for shutter operation.

16., In a device of the class'described, a fire-prevention film shutter, a pivot member therefor, a worm mechanism on the pivot member, a toothed member for engaging the worm having speed ratio with the film travel, and'tension means holding the shutter normally closed and influencing said worm mechanism to provide motion escapement of the tooth member until a safety film speed is attained, said tooth and worm mechanism coacting to definitely open and hold open the shutter at a predetermined safety film speed.

17. In a device of the class described, a fire-prevention film-shutter, tension means holding the same normally closed, a shutterpivot, a worm member thereon, a film feed sprocket wheel and a toothed member thereon adapted to progressively engage the shut ter pivot worm threads when a predetermined sprocket wheel speed is attained to open the shutter.

18. In a device of the class described, a fire prevention film shutter, a film feed member and coordinating pitch members connecting the shutter with the film member, the pitch angle of advance being ineffective to open the shutter at low speeds, and functioning to open the shutter at predetermined high speeds, said coordinatingmembers being provided with means functioning to hold the shutter open at said high or safety film speeds.

19. In a device of the class described, a normally closed fire-prevention film-shutter, a tension normalizer therefor, a member having speed ratio with the film travel, and pitch type connection between said .member and shutter, the angle of advance, and the tension degree of the normalizer, being arranged in relation to the speed variation of said member to render the gearing action ineffective until a predetermined speed of the driver is attained, whereupon the shutter is positively opened or closed by the speed control, and mechanically held open under the sole influence of a safety film speed. v

In witness whereof, I hereunto subscribe my name, as attested by the two subscribing witnesses.

JOHN T. WELLS. Witnesses:

CLARENCE B. Fos'rnR, L. A. B -K.

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