US1538391A - Safety attachment for motion-picturf machines - Google Patents

Description

May 19, 1925.

R. FINE SAFETY ATTACHMENT FOR MOTION PICTURE MACHINES 3 Sheets-Sheet 1 Filed Nov. 8, 1922 g, (like: new;

May 19, 1925. 1,538,391

R. FINE SAFETY ATTACHMENT FOR MOTION PICTURE MACHINES Filed Nov. 8, 1922 3 Sheets-Sheet 2 RaZerZ I'd/2e May 19, 1925. 1,538,391

R. FINE SAFETY ATTACHMENT FOR MOTION PICTURE MACHINES Filed Nov. 8, 1922 3 Sheets-Sheet 5 Patented May 19, 1925. v

UNITED STATES 1,538,391 PATENT: OFFICE.

ROBERT FINE, OF WILKES-BARBIE, PENNSYLVANIA, ASSIGNOR OF ONE-FOURTH TO JOHN V. KOSEK, OF WILKES-BABRE, PENNSYLVANIA.

SAFETY ATTACHMENT FOR MOTION-PICTURE MACHINES.

Application filed November '1 '(i all whom it may concern:

lie it known that I, Ronnn'r FiNE, a citizen of the United States, residing at VVilkes- Barre, in the county of Luzerne and State of Pennsylvania, have invented certain new and useful Improvements in Safety Attachments for Motion-Picture Machines; and I, do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to attachments adapted to be applied to standard motion picture projecting apparatus for the purpose of preventing ignition of the film by the heat of the light source should the film cease to feed properly through the machine.

Objects of the invention are to enable the film, in case of breakage thereof or improper fced, to automatically cause ashutter or douser to be interposed between the source of light and the film; to automatically stop the operation of the picture machine in response to breakage of the film; to simplify the construction of safety mechanisms for motion picture machines and to render cer tain the automatic actuation thereof.

The invention consists of the combinations, subcombinations and details of construction more specifically described hereinafter, illustrated in the accompanying drawings and defined in the appended claims.'

I have illustrated a preferred embodiment of the invention in the accompanying drawings wherein like parts are indicated by like reference characters.

In the drawings,-

Fig. 1 is a side elevation (parts being shown in section) of so much of a standard motion picture projecting machine and light projector as is necessary to illustrate the application of this attachment thereto;

Fig. 2 is a top plan view of a motion picture machine, the light projecting apparatus having been omitted;-

Fig. 3 is a front elevation of a portion of i the light projector showing the shutter or douser closed;

, Fig, 4 is a side elevation of a fragment of the. apparatus illustrated in- Fi 3, the

shutteror douser being shown in a position assumed during the act of closing;

Fig. 5 is a diagrammatic perspective of a 8, 1922. Serial No. 599,693.

fragment of the lower portion of the picture machine illustrating the course of the picture strip or film;

Fig. 6 is a perspective view of an automatic circuit breaker attached to the light projector and forming a part of the mechanism for automatically stopping the picture machine, and

Fig. 7 is a diagram of a circuit including the circuit breaker.

In Fig. 1, A indicates, as a whole, a standard motion picture machine in eonnnon use and B indicates, as a whole, a part of a light projecting apparatus used in connection with the picture machine. It will be understood that the part B comprises a tube 1) defining a light emitting orifice through which a strong beam of light is projected from a powerful arc lamp or other source of illumination (not shown) arranged in the rear, or at the right thereof viewed as in Fig. 1. It will also be understood that a condenser is interposed in the light beam as usual and that the axis thereof coincides with the axis of the usual projection aperture in the picture machine A. The heat of the beam projected through the tube b and through the projection aperture of the picture machine is of such high temperature that the inflammable picture strip or film of celluloid is likely to become ignited should the film stop or feed too slowly.

The picture strip or film F is, in practice, led from a reel or spool -(not shown) supported above the picture machine and is fed intermittently across the projection aperture through the machine and wound upon a receir ing reel or spool (not: shown) disposed below the machine.

In a typical motion picture machine of the type with which this attachment is designed to be used, the film is threaded first around a guide roller 0, then over an initial continuous feed roller (1. having sprocket teeth which engage corresponding openings in the edge of the film beneath a roller a which keeps the film in engagement with the sprocket teeth of roller a; it then extends forward in an initial loop f, then over a guide a. whence it is drawn step by step across the projection aperture by an intermittent feed device, such as toothed roller a between which and a retaining roller (1 said film passes. thence in a final loop I" about a yielding tension lid roller a and over a final continuous feedwide open. In Fig. 1 the shutter is shown roller a". having teeth engaging in the openings of the film, the film passing between said roller a and a film-retaining roller a. downward to the receiving reel. In practice the relative speeds of the feed rollers a and a, with respect to the intermittent feed device 0., is such that, when the film is properly threaded through the machine, loops are formed at f and f, affording suitable slack for the proper operation of the intermittent feed. The mechanism thus far described is common and well-known and forms no part of my invention. The improvement for which I seek a patent will now be described.

In the embodiment herein illustrated, numeral 1 indicates. a box or casing mounted in any suitable manner above the tubular 4, pivote part b of the light projection apparatus. Within this box is a motor controller shown as a circuit breaker comprising a base 2 of insulating material upon which are mounted twin s ring contacts 3 and a knife switch (I at 5, having an insulated handle 7 and biased to open position by spring 6. Leads 0 and cextend from the contacts 3 and knife switch 4. The said leads '0 and 0 may extend through the box 1, as indicated in Fig. 1, and constitutes a part of the circuit C between the motor M and a source of electrical energy G. A service switch S may be interposed in the circuit C for the purpose of opening and closing said circuit manually at will. Assuming the service switch S to be closed, the circuit will also be closed during the normal operation of the picture machine by the'circuit breaker within the box 1. Should, for any reason, the film fail to feed properly and assume in whole or in part an abnormal position, the circuit breaker will automatically open to stop the machine by reason of the construction and mode of operation of the mechanism to be presently described.

Projecting from the front portion of the box 1, at one side, is a bracket arm 8 having at its front end a lip 9 and a plane shoulder 10. Pivoted at 11 on the upper side of tube 6 at its front is a relatively heavy shutter or douser 12, which is adapted to fall by gravity and be maintained by gravity across the opening in the tube 6, thus completely intercepting the beam projected from the light source. The shutter 12 is shown as having a 'strap 12 riveted to it, the end of said strap projecting beyond the free edge of the shutter to form a finger piece 12". Projecting substantially perpendicularly from the central portion of the shutter 12 (struck out from strap 12 as shown) at the rear, is a lip 13 adapted to engage over a latch plate 14 on the end of knife switch 4 when the circuit breaker is closed and the shutter is raised to its highest point, or is in its wide 0 en position-with the lip 13 engaged over t ie latch plate 14, in which condition the circuit breaker is closed and the beam of light is being projected through the tube 6 and the pro ection aperture of the picture machine.

In order to retain the parts in the position illustrated in Fig.1, the shutter is latched upward by a pivoted spring latch member 15 adapted to engage a latch lug 16 projecting laterally beyond one edge of the shutter 12, said latch lug 16 being adapted to en age with a' locking lip 17 formed by a note cut in the lower edge of the latch. The latch 15 is pivoted at 18 on the bracket arm 8 before referred to and is normall held in position to interlock with the latch lug 16 by a coil s ring 19 one end of which is secured to the x 1 at 20 and the other to the latchmember 15 at 21. Under normal conditions, when the shutter 12 is raised-and reaches its highest position, the

lug 16 will engage the inclined end of the locking lip 17 of latch 15 and the said lip will snap over the lug so as to interlock wit it, the spring 19 holding the latch engaged with the lug and thus retaining the shutter in its highest position. Lug 16 is then inengagement with the front shoulder 10 of the bracket arm 8 and rests over the lip 9. In this position of the shutter the -lip 13 will be engaged over the latch plate 14 on the knife switch 4 if the latter shall have been manually depressed in order that this engagement may takeplace and will maintain the motor circuit closed.

The mechanism for automatically releas ing the shutter and automaticallyo ning the circuit breaker will now be descri d.

The latch 15 is adapted to be operated in opposition to the tension of the spring 19 by means of a link 22 pivotally connected at 23 to said latch and having a hook-like formation 24 at its other. end adapted to be engaged by devices that respond to various conditions of the film, due to improper feed or breakage thereof, and operate to pull the link 22 endwise to the left, as viewed in Fig. 1, thereby releasing the shutter and opening the circuit. breaker to intercept the light beam and stop the machine. Inside of the loop f, in such position that it will be engaged by the film in case the loop is tightened or shortened to an abnormal degree, is a link actuator 25 held elastically projected into the position shown in Figs. 1 and 2 by compression springs 26, which surround arms 27 extending in parallel relation from. said member 25 and suitably guided in slide bearings on the machine frame as indicated at 28. This actuator 25 is designed to be engaged by the hooked end 24.0f the link 22.

erally from the actuator into a position such that the end of the link 22 may be hooked over it. From this construction it will be apparent that link 22 will be pulled endwise and unlatch the shutter 12 if the loop f draws up sufiiciently to engage the actuator 25 and move it inward against the tension of the springs 26. I

In' order that the latch 15 may be caused to release the shutter in case the loop f shortens an abnormal amount, the following devices are provided A bell crank lever 30 is pivoted as at' 31 adjacent the lower portion of the machine frame in a bearing block 30. This lever has an upward extending arm 32, a laterally bent bearing portion forming the pivotal part, and an arm 33 bent at its extremity as at 34, on which may be a roller 34 that overlies the loop engagin roller 0 and extends within the loop f. onnected to the upper end of arm 32 of said lever 30 is a slide bar 35 suitably guided in bearings 36 attached to the machine frame and having a laterally extending end 37 arranged in position tobe engaged by the hooked'end 24 Of SQld link 22,as shown in Fig. 1,-im'med1ately below the pin 29 of the actuator 25. The arm 34 of this particular portion of the mechanism serves as the actuator. In case the loop tightens or shortens to an abnormal degree owing to disordered feed, the roller a will be.drawn upward into engagement with the arm '34, thus actuating the bell crank lever 30, moving the slide rod 35 endwise to the left, (as viewed in Fig. 1) and pulling the link 22 in such direction as to release the latch from shutter 12, the latter thereupon releasing the knife switch arm 4 of the circuit breaker.

In order to cause the shutter to drop and the circuit breaker to open in case of breakage of the film, the following mechanism is provided I Arm 38 is pivoted at its lower end, as at 39, in a bearing bracket 42, and may have on its upper end an anti-friction member 40 adapted tobear against one face of film F stretched between the feed roller a and the receiving reel, as shown in Figs. 1 and 5. Ann 38 is placed under tension by a spring 41 connected thereto in such manner as to cause the member 40 to press elastically against the film; Pivoted at the upper end of said bracket 42 is a tri lever 43 the opposite end portions of w ich are extended in the same direction, parallel with the pivotal axis 43 of the lever, one end por-.

tion 44 occupying a position beneath the actuating arm 33 of lever 30, and the end part 45 lying in the path of movement of the spring-pressed arm 38. The arm 32 of lever 30. is much longer than arm 33 thereof. It will be apparent, therefore, that an impact of considerable force is necessary to be applied to end of arm 33 in order to over come the tension of the latch spring 19. By reason of the relative position and arrangement of the arm 38, the lever 43, and the proportions of the arms of lever 30, more slacking of the film between the feed roller a and the receiving reel will not cause any actuation of the trip arm 43. In order to actuate the trip arm 43 in such manner as to release the shutter, it is necessary for the arm 38 to strike the part 45 a sharp blow. If, therefore, by reason of slackness of the film F, the arm 38 is lowered gradually into contact with the member 45, the shutter-releasing mechanism will not operate. Should the film F break, however, the arm 38, under the influence of the spring 41, will strike the member 45 a sharp blow causing the trip lever 43 to move the lever 30 with suflic ient force to release the latch 15 from engagement with shutter 12 allowing the latter to close and the circuit breaker to open.

Should the machine be operated by hand instead of by motor, the circuit breaker may be left in open position in which case the actuating mechanism described will cause operation of the shutter or douser only.

In practice the film will be threaded through the machine in the customary manner as indicated in Fig. 1. Improper feed may occur from several causes. The film may become split or portions of its edge broken away so that the upper feed roll will not advance the film. At this time the intermittent feed roller engaging an unmarred portion of the film will shorten the loop f and cause actuation of the mechanism. Should the intermittent feed roller engage a similar marred portion so that it cannot advance the film, the lower loop will shorten and cause actuation of the mechanism. Similar results occur by reason of imperfections of the film, as at points where it. has been repaired, causing it to run off from one or another of the feed rollers and stop or slow up the feed. In the film should break, the arm38 would come into action and actuate the shutter thus avoiding danger of ignition owing to stoppage of the feed; it would also stop the motor. This mechanism may be used in addition to-the shutter or denser customarily applied to machines of the type illustrated and controlled by the speed of the machine. As

ture projecting apparatus comprising an electric motor, film feeding mechanism and a light pro ector; the. combination of a circuit breaker having a bias-to open. position for cont olling the motor circuit, a shutelectric motor, film feeding mechanism and a light projector; the combination of a circuit breaker, having a bias to open position, for controlling the motor circuit, a hinged shutter adapted to be dropped into the path of the light beam, a lip onthe shutter .ar-.

ranged to engage the circuit breaker and hold it closed when the shutter is out of the path of the light beam, and-movable means adapted to be operated under abnormal feed conditions of the film to cause the shutter to intercept the light beam and release the circuit breaker.

3. In a safety appliance for motor operated moving picture projecting apparatus having film feeding mechanism; a light projecting apparatus comprising a member having a light emittingopening, a shut ter hinged to said member above the opening and adapted to drop in front thereof, .a circuit breaker, having a bias toward open position, disposed on said member, a lip on the shutter arranged to hold the circuit breaker closed when the shutter is in open.

position, means for holdin the shutter open and means for releasing tie holding means to permit the shutter to close and the circuit breaker to open. v

4. In a safety appliance for moving picture projecting apparatus comprising intermittent film feeding mechanism adapted to produce loops in the film during feeding,

and a light projector; the combination of a shutter adapted to be moved so as to intercept the light beam, a latch for holding the shutter open, a movable actuator mounted in position to be engaged by the film of the final loop in case of abnormal tightening thereof, said actuator comprising a bell crank lever, a slide member connected to the bell crank lever, a link having one end connected to the latch and the other end loosely engaging said slide member so as to be actuated to release the latch upon movement of the bell crank lever by abnormal tightening of said loop.

5. In a safety appliance for moving picsioned arm having a member adapted to bear upon the surface of the film, a trip arm in position to be struck by said tensioned arm in case of breakage of the film, a link having one end connected to the latch, and means adapted to be movedby the trip for pulling said link to release the latch.

6. In a safety appliance for moving pic'- ture projecting apparatus comprisingfilm feeding rollers, and a light projector; the combination of a shutter adapted tobe moved so as to intercept the light beam, a latch for holding the shutter. open, a tensioned arm having a member adapted to bear upon the stretch of film below the final feed roller, a trip lever having a portion in position to be struck by the tensioned arm in case of breakage of the film, a lever having a relatively short arm in position to be struck by said trip lever, and a relatively long arm extending toward the top of the machine, and link mechanism connected to the upper end of the long-arm of said lever and said latch.

7. In a safety appliance for. moving picture projecting apparatus comprising intermittent film feedin mechanism adapted to produce loops in t e film during feeding and a light projector; the combination of a shutter adapted to be moved so as to intercept the light beam, a latch for holding the shutter open, a movable actuator mounted in position to be engaged by the film of the initial loop in case of abnormal tightening thereof, a movable actuator mounted in position to be engaged by the film of the final loop in case of abnormal tightening thereof, a link having one end connected to said latch and a hook at the other end, each of said actuators having a member in position to enga said hook and pull the link to release said atch, a tensioned arm having a member arranged to engage the surface of the film, a trip lever one end of which is in position to be struck by said tensioned arm in case of breaka of the film, and the other end of which is in position to move one of said actuators to operate the link and release the latch.

- In testimony whereof I afiix my signature.

ROBERT FINE.

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