US1857633A

US1857633A - Motion picture film cleaner

Info

Publication number: US1857633A
Application number: US303678A
Authority: US
Inventors: Joseph G Gramsa
Original assignee: ELMER B CHAPMAN
Current assignee: ELMER B CHAPMAN
Priority date: 1928-09-04
Filing date: 1928-09-04
Publication date: 1932-05-10
Anticipated expiration: 1949-05-10

Description

y 1932- J. G. GRAMSA 1,857,633

MOTION PICTURE FILM CLEANER Filed Sept. 4, 1928 3 Sheets-Sheet l Q JQU May 10, 1932. J. G. GRAMSA MOTION PICTURE FILM CLEANER Filed Sept. 4, 1928 3 Sheets-Sheet gvmm'n foz Lse fi G. Gmms May 10, 1932. J G GRAMSA 1,857,633

MOTION PICTURE FILM CLEANER Filed Sept. 4, 1928 3 Sheets-Sheet 5 Patented May 10, 1932 UNITED STATES PATENT OFFICE JOSEPH G. GRAMSA, OF BUFFALO, NEW YORK, ASSIGNOR OF ONE-HALF TO ELMEB B.

CHAPMAN, OF BUFFALO, NEW YORK MOTION PICTURE FILM CLEANER Application filed September 4, 1928.

This invention relates to improvements in motion picture film cleaners which are particularly intended for, but not necessarily limited to, use as an attachment on a motion picture projection machine wherein they function to clean the film while it is being projected upon the screen. More particularly, the invention is directed to improvements which are applicable to the general construction disclosed in my prior Patent No.

1,581,198 issued Feb. 2, 1926.

Heretofore in devices of this class, the cleaning elements have been held stationary and consequently maintain the same cleaning surface in constant contact with the film until each element is removed and either reversed or replaced by a clean one. If such reversal or replacement is neglected the matter which accumulates on the cleaning surfaces renders the cleaning elements less efficient and may also subject the film to the liability of being scratched.

This invention is directed to a construction which avoids the above objections and has for an object to provide cleaning elements having extensive cleaning surfaces and which are arranged for movement to maintain a relatively clean surface in constant contact with the film.

A further object is'to provide for the easy removal and replacement of the cleaning elements when desirable or necessary.

A still further object is to provide means for driving the cleaning elements from the film operating mechanism whereby the elements are moved automatically and only when the film is being fed through the machine.

A cleaner constructed in accordance with the invention is illustrated in the accompanying drawings, wherein Figure 1 is a side elevation of the cleaner as attached to a motion picture projector.

Figure 2 is a side elevation of the cleaner detached.

Figure 3 is a side elevation of the cleaner with the shafts removed.

Figure 4 is an end elevation of the cleaner as it appears when one part is turned to the in- Serial No. 303,678.

operative position, the operative position being shown in dotted lines.

Figure 5 is a bottom plan view of the cleaner as shown in Figure 1.

Figures 6 and 7 are sections along lines G6 and 7-7 respectively of Figure 2.

Figure 8 is a section along line 8-8 of Figure 7 Figure 9 is a fragmentary view showing the manner of spring latching the shafts.

The cleaner may be applied to any suitable type of projecting machine and is illustrated in Figure 1 in connection with general details of a machine of Well known type, such details being the upper sprocket 1, guide plate 2, lens holder 3, intermittent feed mechanism which is indicated by the showing of its casing 4a and its sprocket 4b, and lower sprocket 5, all of which are arranged in the usual manner. During the operation of the projector, the film F passes from the reel R1 over the upper sprocket 1, thence over the guide plate 2 across the aperture of the machine and around the sprocket 4b to the lower sprocket 5, after which it is taken up by the take-up reel R2. To prevent the film from rewinding on the lower sprocket 5 in the event of its breakage at a point below said sprocket, it is customary to employ a plate 6 which extends under and rides against the lower sprocket 5, the plate being formed with slots 7 which provide clearances for the sprocket teeth. The plate 6 is supported in this position by a post 8 which projects laterally from the projection machine.

The film cleaner is illustrated generally at C in Figure 1 and while it may be located as desired, it is preferably located between the sprocket 4b of the intermittent feed mechanism and the lower sprocket 5. The cleaner C operates upon that portion of the film lying between these sprockets, such portion being arranged in the form of a loop. The post 8 provides a convenient support for the film cleaner in the position described and the cleaner is secured theretoby a screw which is threaded to the post with its shank extending through an aperture in a plate 9 carried by the cleaner and with its head engaging said plate with clamping effect.

The cleaner C includes a pair of cleaning elements (Fig. 8) 10 and 11 composed of textile or other suitable material and preferably in the form of strips, the opposite ends of each strip being wound upon

individual spools

12 and 13. That portion of each element intermediate the

spools

12 and 13 is arranged to operate upon the opposite faces of the film, preferably engaging the picture bearing part only, to prevent the tearing of the marginal portions of the film which are weakened by the provision of sprocket holes as related in my prior patent. The operation of the elements may be aided, when (lesirable or necessary, by impregnating them with a suitable cleaning fluid.

The cleaning elements are maintained in engagement with the film F by

members

14 and 15 respectively which preferably are of channel form andv arranged in back to back relation to define a space through which the film and cleaning elements extend and in which they are pressed together. The elements are fitted in grooves formed in the back of their respective members to hold them in alignment with the picture bearing portion of the film. The

members

14 and 15 are hinged together at one side along a line parallel to the longitudinal axis of the film as at 16 whereby one member may be swung transversel away from the other member to expose tl ie cleaning elements and the film. The opposite sides of the members carry cooperating latching elements comprising a spring latching finger 17 and pin 18 by which they are held in operative relation. One of the members also carries the plate 9 by which the cleaner is mounted on the post 8.

The

members

14 and 15 also function to support the cleaning elements 10 and 11 (see Figures 6 and 7) and to this end the spool 12 of each element is transversely arranged in the channel of the corresponding member, being mounted on a shaft 19 while the spool 13 of each element is similarly arranged and mounted on a shaft 20, these shafts, in turn, being journaled in the sides of their respective member. It may be noted at this time that the spools 12 are of uniform bore and thus free to turn about the shafts 19 whereas the spools 13 are formed with square portions to receive similarly formed portions on the shafts 20 and thus lock the spools to their respective shafts. To facilitate the quick removal and replacement of the

shafts

19 and 20 and consequently of the

spools

12 and 13, one side of the

members

14 and 15, preferably the hinged side, carries light springs 21 which engage grooves 22 formed in the adjacent ends of the

shafts

19 and 20, to spring latch the shafts in position. Thus to remove the shafts it is necessary only to pull them out from the opposite side of the channel members with suflicient force to unlatch them, it being noted that the shafts are provided with knobs 23 for this purpose. The replacement is of course, effected in the opposite manner. \Vith the shafts removed, the spools are freely removable and consequently to remove the cleaning elements it is only necessary to unlatch and open the

members

14 and 15.

The movement of the cleaning elements is accon'iplished by driving the shafts 20 so as to wind the elements around the spools 13, the spools 12 being unwound b the pull of the elements. The drive of the shafts 20 may be accomplished manually or automatically and by any suitable means. Preferably the cleaning elements are driven from the projecting machine inasmuch as it affords a convenient source of power and, where the cleaner is positively connected to the projecting machine, it has the advantages of providing an automatic drive and one which is efl'ective only when the film is being run-through the machine this being the only time cleaning is necessary. In the arrangement shown, the lower sprocket 5 provides a convenient means of driving the elements from the projecting machine. This sprocket, however, rotates at a high speed and it is necessary, therefore, to provide a speed reduction arrangement.

The speed reduction arrangement includes intermeshing gears 24 which are locked upon, or formed integrally with, the driving shafts 20 and a gear 25 similarly secured to one of the shafts 19 and meshing with one of the gears 24. It is evident that the rotation of the gear 25 causes both gears 24 to rotate and thus effects the drive of the shafts 20. The gear'25 is connected to a cam 26 formed on the lower sprocket 5 by intervening pawl and ratchet mechanisms which provide the necessary speed reduction. The pawl and ratchet mechanisms may be arranged in any desired manner and mounted on either supporting

member

14 or 15. As shown they are mounted on the member 15, the pawls 27, 27a being pivoted directly to the member 15 and the

ratchets

28, 28a bein loosely mounted on hubs 29 formed integrally with the member 15 around the

shafts

19 and 20. The connection between the gear 25 and the adjacent ratchet 28a is provided by a pin 30 secured to the ratchet 28a and extending through an aperture in the gear while the connection between the ratchets is effected through the action of a pin 31 on the ratchet 28 upon the pawl 27a of the ratchet 28a.

In the operation of the device, the rotation of the cam 26 on the lower sprocket 5 effects the drive of the cleaning elements through the pawl 27, ratchet 28, pin 31, pawl 27a, ratchet 28a, pin 30, gear 25, ears 24, shafts 20 and spools 13. When it is esired to operate the projecting machine without driving the cleaning elements the pawl 27 can be moved out of operative relation with the cam to a point where its ratchet engaging arm extends vertically under its ratchet so as to prevent the return of the pawl to its operative position. For the purpose of preventing any movement of the ratchets or gears-at this time while permitting their movement by the pawls at all other times, the member 15 carries springs 32. 320 which engage the

ratchets

28, 28a respectively. The invention also contemplates the provision of additional removable pins 31 to the ratchet 28 or of means to render the throw of the pawls adjustable to permit variation in the speed of the cleaning elements. Such modifications are, however, so obvious and well known as to render illustration thereof unnecessary.

Having fully described my invention, I claim:

1. A cleaner for motion picture films comprising a pair of cleaning elements arranged alon the opposite faces of a film, channel members placed in back to back relation with their adjacent faces arranged to define a space through which the film and cleaning elements extend and in which the elements are maintainedin contact with the film to clean the latter during the operation of the device, a pair of spools mounted in the channel of each member, the opposite ends of each cleaning element being wound upon the spools-of the adjacent channel member and means for turning each pair of spools in Winding-unwinding relation so as to move the cleaning elements through said space so as to change the surface portions engaging said film and thereby maintain a relatively clean surface in contact with the film.

2. A cleaner for motion pictures films comprising a pair of cleaning elements arranged along the opposite faces of a film, channel members placed in back to back relation with their adjacent faces arranged to define a space through which the film and cleaning elements extend and in which the elements are maintained in contact with the film to clean the l latter during the operation of the device, a

pair of shafts mounted on each of said members and extending transversely through the channels thereof, a spool mounted on each shaft, the opposite ends of each cleaning element being wound upon the spools of the adjacent channel member and the shafts being readily removable from the sides of said members to facilitate the removal and replacement of the spools, and means for turning the spools of each channel member in windingunwinding relation so as to move the cleaning elements through said space so as to change the surface portions engaging said film and thereby maintain a relatively clean surface in contact with the film.

3. The combination with a motion picture projecting machine having driving means for moving a film through the machine of a film cleaner comprising a pair of cleaning elements, the opposite ends of which are wound upon spools, said elements bein arranged along the opposite faces of the m with a portion intermediate the spools in contact with the film to clean the latter during the operation of the device and means fo. effooting the drive of said spools in windingunwinding relation from said film driving means so as to change the portions of said elements in contact with the film thereby to maintain a relatively clean surface in contact with the film.

4. The combination with a motion picture projecting machine having a rotatable part which rotates when the film is being driven through the machine of a film cleaner com-' prising a pair of cleaning elements, the opposite ends of which are wound upon spools, said elements being arranged along the opposite faces of the film with a portion intermediate the spools in contact with the film to clean the latter during the operation of the device and speed reduction means connecting said spools with said rotatable part for effecting the drive of said spools at reduced speed and in winding-unwinding relation whereby the cleaning surface in contact with the film is changed during the operation of the film.

5. A cleaner for motion picture films comprising a pair of channel members arranged in back to back relation with their adjacent faces defining a space through which a film may be passed, a pair of spools 'rotatably mounted in the channel of each member and a cleaning element for each pair of spools, each element having its opposite ends wound upon the spools and its intermediate portion extending through the space between said channel members to engage the opposite faces of a film when the latter is passed through said space, said spools being arranged for rotation in winding-unwinding relation whereby the intermediate portion in contact with the film may be changed.

6. In a motion picture machine the combination with the film feeding mechanism thereof of a film cleaner comprising a cleaning element, means for supporting said element, means arranged to maintain a portion of its surface in contact with the film, and means operatively connected to the said film feeding mechanism for feeding said element in the direction of its length so as to change the surface portion of said element in engagement with the film.

7. In a motion picture machine the combination with the film feeding mechanism thereof of a film cleaner comprising a cleaning element, means for supporting said element, means arranged to maintain a portion of its surface in contact with the film, and means operatively connected to the said film feeding mechanism for producing relative movement between said last mentioned means and said element so as to change the surface portion of said elementin engagement with the film without interrupting such engagement.

8. In a motion picture machine the com- 5 bination with the film feeding mechanism thereof of a film cleaner comprising a pair of spools rotatably mounted on said machine, a cleaning element the opposite ends of which are wound-about said s 0015 and the intermediate portion of whic is adapted for engagement with the film to clean the latter during the operation of the device, said spools being arranged for rotation in winding-unwinding relation whereby the intermediate 1 portion in contact with the film may be changed and means for operating said spools by said film feeding mechanism. 7

9. In a motion plcture machine the combination with the film feeding mechanism thereof of a film cleaner comprising a pair of cleaning elements, the o posite ends of which are wound upon spoo s, said elements being arranged along the opposite faces of said film wlth a portion intermediate the 2.5 spools in contact with the film to clean the latter during the operation of the device and means operatively connected to the said film feeding mechanism for turning said spools in winding-unwinding relation so as to 80 change the surface portions engaging said film thereby to maintain a relatively clean surface in contact with the film.

In testimony whereof I afiix my signature.

JOSEPH G. GRAMSA. 85