US1305804A - Motion-picture machine - Google Patents

Description

c. F. JENKINS. MOTION PICTURE MACHINE. APPLlCATiON Fl ED] I 1,305,804. Patented June 3,1919.

UNITED STATES ratrENT ornion.

CHARLES FRANCIS J ENKIN S, 015 WASHINGTON, DISTRICT OF COLUMBIA.

' MOTION-PICTURE MACHINE.

Application filed July 17, 1918.

To all whom it may concern Be it known that I, CHARLES FRANCIS J ENKINS, a citizen of the United States, and

' resident of ashington, in the District of Columbia, have invented certain new and useful Improvements in Motion Picture Machines, of which the following is a specification, reference being had therein to the accompanying drawing.

In motion picture work the danger of tire is now in most places limited, by more or less objectionable means,'to loss of film and injury to the' machines used, with interruption of business, but the film ordinarily exposed to fire hazard represents a considerable value, and the injury to the machine and interruption' of business are often extremely important. The leading object of this invention is to prevent burning of more than an insignificant amount offilnn and to avoid delays and injury to the apparatus.

In the accompanying diagrammatic drawings,

Figure l is a plan view showing an embodiment of the invention in a part of a casing for film feeding devices of any suit-- able type.

Fig. 2 is a sectional elevation showing the same devices. I

Fig. 3 is an enlarged cross section of rollers seen also in the other figures.

In these drawings, A represents a space within a casing B for film feeding devices and C a chamber for film carrying reels, a table E being interposed between the two chambers and cut away to allow film to pass upward from the lower chamber into the one above and to return when desired, two film reels being usually mounted in a well known way in the lower chamber. As shown in this instance, the chambers conimunicate through a single opening F which is forwardly closed when the apparatus is in operation by a closely fitting door 0 lying very near the ends of the rollers. Slightly above the table and directly over the passage through the table a roller H is mounted upon a stud I, and on one side of this roller a coacting roller J is mounted on a stud J of materially smaller diameter than the passage through the roller and having its axis a little above the horizontal plane of the axis of the roller H. ()n the opposite side of the latter roller is similarly mounteda roller K, its stud K, like the stud J, being so placed Specification of Letters Patent.

Patented June 3, 1919.

Serial No. 245,418.

that its line of contactwith the interior of the roller is not vertically above the axis of the stud when the roller is in contact with the roller H.

Owing to this arrangement, gravity gently urges the outer rollers toward the middle roller. It follows that if film be placed between the rollers as shown at L, L, it will at all times be lightly pressed thereby although no material resistance to its advance will be caused. Should the film be ignited above the rollers the fire will be pinched out when it reaches the contact line of either pair of rollers. This would be true were the rollers raised to any temperature below.that required for igniting the film.

Usually the rollers are at atmospheric temperature, and when that is the case, combustion, if not pinched out, would probably be arrested by the abstraction of heat in the narrow space, the rollers being good conductors of heat; but in any case the use of the expedient set forth seems to secure absolute safety. In long practical use of many machines and in almost innumerable experiments, fire has never passed into the reel chamber; and since the length of the portion of the film found at any time in the upper chamber, never exceeds a foot or two, its loss is of little consequence and its quantity is too small to create heat capable of seriously injuring the mechanism.

Obviously, were the film not returned to the chamber C the action would be the same, although in that case but two rollers would be active, onnecessary, at this point, at least.

What I claim is:

1. The combination with a film chamber having above an aperture for the passage of a film strip, of a horizontal roller mounted alongside the path of film passing through said aperture, and a second parallel roller mounted on the opposite side of said path, to swing, freely, pendulum-like. without ap preciable vertical movement. about an axis above its own axis and slightly nearer the vertical plane of the axis of said horizontal roller, whereby both rollers may be kept with certainty in contact with the film by ex tremely slight pressure.

2. The combination with a film chamber having above a narrow opening for the outward and inward passage of film, Of a roller mounted in position to separate outgoing from incoming film, and two other ollers mounted to swing about axes above their central line against opposite sides of the roller first mentioned.

3; The combination with two communicat ing film'chambers, of three rollers in position for closing the communication against the passage of fire, two of said rollers arranged to press yieldingly against-opposite sides, respectively, of the third roller.

+L. The combination with two superposed film chambers communicating through an opening allowing the passage of film, of a roller obstructing the middle part of said opening, and two other rollers mounted on opposite sides, respectively, of the roller first mentioned, obstructing the remainder of said opening, and arranged to be constantly urged toward the first mentioned roller by gravity, whereby film passing upward on one side of the middle roller and down upon the opposite side is prevented from transmitting combustion from one chamber to the other. 5. In apparatus of the class described, the combination with a revolubly mounted hollow horizontal roller, of a parallel roller alongside the roller first mentioned and supported on a stud of a diameter materially less than that of the rollers interior and having its axis slightly above the axis of the first roller and at a distance therefrom less than the sum of the radii of the two rollers. In testimony whereof I hereunto afiix my signature. I

CHARLES FRANCIS J ENKIN'S.

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