US1909074A - Motion picture apparatus - Google Patents

Description

May 1 1933- E. w. REYNOLDS- IQTI ON PICTURE APPARATUS Filed April 17, 1931 INVENTOR 5 2120000 14/. Reynolds.

A'TTORNEY WITNESSES:

Patented Ma 16,1933

} UNITED s A'rEs mmwoon w. narrows, or nmsxn'r. HILL, PENNSYLVANIA, assmnoa 'ro wnsrrka-f PATIENT OFFICE HOUSE ELEL'IBIC & MANUFACTURING COMPANY, A CORPORATION 01 'VAN'IA MOTION PICTURE APPARATUS v Application fled April 17, 193;. Serial no. 580,778.

My .invention relates to web-handling apparatus and has particular relation to apparatus for regulating the speed of a web as it is advanced.

5 The present application is a continuation in part, of my co-pending application, Serial No. 436,552, filed March 17, 1930, and assigned to Westinghouse Electric and Manufacturing Company. Certain of the features shown but not claimed in the present application are shown and claimed in my copending application, Serial No. 650,375, filed January6, 1933 and in the following a plications: Serial No. 406,847, filed November 13, 1928 to Clinton R. Hanna and Emil H. Greibach; Serial No. 461,274, filed June 16, 1930 to William Laudenbach and Francis Herdon; Serial No. 524,879, filed March 24, 1931 to Clinton R. Hanna; Serial No. 640,262, filed October 29, 1932 to Clinton B. Hanna and Eniil H. Greibach; Serial No. 663,377, filed March 29, 1933 to Clinton R. Hanna. 1

Apparatus for regulating the speed of a web, as it is advanced through a web-handling machine, such as a motion-picture machine, ordinarily comprises a low-pass mechanical filter which includes a resiliently mounted sprocket for advancing the web and an inertia roller rotated by the advancing web. These mechanical filters are particularly applicable in photo-acoustic a paratus wherein it is highly desirable that a lm strip be advanced at a: substantiallyuniform sp'ee' In working with photo-acoustic apparatus, I have found that the filtering systems. constructed according to the teachings of the prior art, which comprise, as has been pointed out, a single resiliently mounted sprocket and a single flywheel, ordinarily occasion I considerable difliculty. The. flywheel should be of comparatively large inertia and, as a result, considerable tension is required in the film to rotate it uniformly. The expense involved in the provision of substantially frictionless bearings for the inertia roller is an item of no small importance. Moreover, in view of the fact that the. ordinary film strip is not a highlyxelastic medium, it is deleteriously affected by tensional forces of ordinary "magnitude. These features, when combined,

vention is to provi render the problem of providing for the application of the necessary torque to the rotation of the inertial mass in the filtering system, a comparatively difiicult one.

Certain attemptshave also been made to bring the film strip into more intimate engagement with the surface of the inertial roller by providing a plurality of pressure rollers that engage the film and hold it in firm contact with the inertia roller. However, I have found that the pressure rollers, by the irregularity of their reaction of the film, introduce a dls'tortion in the sound that 'is produced from a film strip passing through a machine of such structure.

It is, accordingly, an object of my invention to provide a mechanical filterfor a web-- handling system wherein the re uisite inertia mass shall be rotated with facility.

Another object of my invention is to provide a mechanical filter for web-handling apparatus wherein the inertia mass shall be ro-- tatgd with comparatively small tension in the we Still another object of my invention is to provide apparatus of the type wherein a large mass to be rotated shall be effectively coupled to a web without the aid of additional.

pad rollers or prohibitive tension.

A further object of my invention is to rovide a mechanical filter for a web-ban g system wherein a web is held in engagement with theinertial mass .by the tension forces in the web. v A still further object of my invention is to provide a mechanical filter for a web-handling system wherein pad rollers are not requiredto hold the web in engagement with the inertial mass.

'An incidental object of my invention is to provide a shoeless gate for film-handling apparatus.

A further incidental object of my invention is to provide web-handling apparatus wherein the web web-handling mechanisms on one of its surfaces only. r

A still further incidental object of my inde photo-acoustic a params of a type wherein the adshall be engaged by a plurality of 1 vanced in such manner as not to be mechanically marred on the surface on which the acoustic waves are recorded.

More specifically stated, it is an object of my invention to provide web-handling apparatus of the type wherein a web shall be advanced smoothly and uniformly without being excessively tensioned or broken.

,According to my invention, I web-filtering system wherein the or inary inertial mass utilized is broken up into indi-- vidualjparts instead of being contained in a single unit. That is to say, in apparatus constructed according to the teachings of my invention, a plurality of inertia rollers are }utilized instead of a single web-driven inertia roller, and the sum of the inertias of these rollers is made equivalent to the necessary inertia of the sing e web-driving roller of the prior art.

The effective angle of contact between the web and the roller is thus increased considerably and may, in fact, attain a value greater than 360. The increase in the angle of contact results in an increase in the effective coupling between the mass and the web and, consequently, in an increase in the longitudinal force that must be applied to the web before it will slip relative to the rollers.

In view of the fact that, in a plural-roller system, the inertia of each individual roller is considerably smaller than the inertia of the single roller of the apparatus of the prior art, considerable less tension in the web is required to initiate the rotation of the rollers embodied in my improved system. More,

I is smaller than the weight of the single roller,

over, since the weight of the individual rollers less tension is required in the web to overcome bearing friction and to maintain the .et wheels. The sprocket wheels perform the combined functions of providing for the tensioning ofthe web and of preventing the irregularities of the mechanical elements of the machine and of the web from being introduced into the portion of the web that is required to move uniformly.

In the specific embodiment of my invention, I have provided a surface to support a web, on each side of which a resiliently mounted sprocket wheel is disposed. One of the sprocket wheels is disposed below the surface and, when driven through the resilient coupling,it advances the web.

The second sprocket wheel is disposed above the web-supporting surface and is rotated by the web. It is resiliently coupled to a damping device and, by reason of the damping, exerts a tension on the web. An

rovide a inertial roller is associated with each sprocket.

It is to be noted that,in view of the fact that the sprocket wheels are resiliently supported, the variations between the sprocket wheel pitch and the sprocket-hole'pitch of the web is taken up in the coil ling and is not transmitted to the web. urthermore, by reason of the fact that the web-rotated sprocket wheel is resiliently mounted, the irregularities that ma be present in the damping device are eliminated and do not appear in the motion of the web.

In one embodiment of my invention, the web-supporting surface is an ordinary skid that is stationary relative to the web. In a second embodiment of my invention, the

the specific embodiments of my invention that will be described herein.

The novel features that I consider characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, to-

.gether with additional objects and advantages thereof, will best be understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which Figure 1 is a schematic view, in front elevation, showin the essential elements of an embodiment o my invention;

Fig. 2 is a view, in section, taken along the line II-II of Fig. 1 and showing the mounting of the sprocket wheels utilized in my invention;

Fig. 3 is a perspective view, certain parts being broken away, showing a resiliently mounted sprocket wheel utilized in the practice of my invention, and

Fig. 4 is a schematic view, in-front elevation, showing a modified embodiment of my invention.

The apparatus shown in Figs. 1, 2 and 3 comprises a plurality of web-engaging sprocket wheels 1, 3 and 4 to advance a web 5 over a skid 7. In view of the fact that my invention has been, in general, applied to photo-acoustic apparatus, it is shown in the present embodiment of my invention as applied in this field. Specifically, the web 5 is, therefore, a photo-acoustic film.

A section of the telescope 9 of a soundreproducing optical system is disposed adjacent to the film 5, and a photo-tube 11, respom sive to the variations in the light transmitted through the film 5, is disposed behind the film. The skid 7 is equipped with an aperture 13, through which the light from. the

web supporting surface is a drum rotated optical system is transmitted to the cell 11 and is commonly known as an aperture plate. Fig. 2 may be regarded as an enlarged transverse section, taken along the line II-II of Fig. 1, with all the elements but the sprocket wheels 1 and 3 omitted for purposes sprocket wheel on the shaft is permitted.

To prevent the free oscillation of the sprocket wheel 3, a damping washer 25 of suitable material, such as felt, is provided to be compressed between the sprocket wheeland a collar 27, rigidly secured to the shaft, by a spring 29 that engages the bearing 31, in which the -shaft rotates, and one face 33 of the sprocket wheel.

The upper sprocket wheel 1 is rotatably supported on a sleeve 35 that is, in turn, rotatably mounted on astud '37 secured in the main base 39 of the system. The sleeve 35 is resiliently coupled to the sprocket wheel 1 by a spring 40. in a manner similar to that in which the driven shaft 15 is coupled to its corresponding sprocket wheel 3 by the spring 19. The sleeve 35 is mechanically damped by a washer 41, of suitable material, that is compressed between the sleeve and a collar 43 and resiliently urged toward the sleeveby a fiat spring 15 that. in turn, engages a second collar 47 rigidly secured to the stud 37. The collar 43 that is in engagement with the damper washer 41 is rotatably mounted on the stud 37 and is equipped with a pin 49 which engages the threads 51 of the stud.

The sprocket wheel 4 is, ordinarily, a holdback sprocket wheel, disposed between the take-up reel (not shown) and the pulling sprocket wheel 3 and is rigidly secured on a driven shaft 53.

A plurality of rollers 55 and 57, to be filmdriven, are associated with the sprocket wheels 1 and 3. The film between the sprocket wheels 1 and 3 is maintained in tension by reason of the fact that the motion of the upper sprocket wheel 1 is damped and offers a resistance to the force exerted by the driven sprocket wheel. By reason of its tensioned condition, the film 5 is held in intimate engagement with the rollers 55 and 57.

It is to be noted that the damping device would have a tendency to introduce distortions in the velocity of the film, if the resilient coupling 40 were not included between the damping means and the sprocket wheel 1. By reason of the fact that the film is tensioned, shoe plates are not necessary on the filnrsupporting surface, and one of the inost diflicult problems that has arisen in connection with photo-acoustic apparatus is substantially solved.

In Fig. 4, apparatus of a type comprising elements similar to those of Fig. 1 are shown. In this case, however, the film is supported on a drum 59. In photo-acoustic apparatus of this type, the sound is ordinarily taken off by allowing the section of the film 5, wherein the sound track is impressed, to project over the edge of the drum 59 and, by suitably disposing the optical telescope 9 and the phototube 11 relative to the film. In the apparatus illustrated in Fig. 4, the photo-tube 11 is shown as disposed within thedrum.

In view of the fact that a substantial angle of contact between the drum 59 and the wcb 5 is necessary for proper operation, a plurality of web-deflectingfrollers 61 are pro vided between the drum and the inertial rollers 55 and 57.

In the description given hereinbei'ore, my invention has been shown as embodied in a specific system. and has been, as a matter of fact, essentially illustrated schematically. In ordinary welrhandling apparatus and particularly in film-handling apparatus, certain refinements are introduced. It is understood that machines incorporating these refinemcnts lie within the scope of my invention if they also incorporate the essential features of my invention. as described herein.

Moreover, it will be noted that certain modifications of the apparatus described herein are possible. It is apparent that my invention may be practiced in a system wherein both of the resilient sprocket wheels are driven. As a matter of fact, I have experimented with apparatus of this type and have found it to operate satisfactoril Another modification of my invention that is apparent is one wherein the lower sprocket wheel 3 is driven at normal speed, while the upper sprocket wheel 1 has a peripheral speed greater, by a slight amount, than the peripheral speed of the lower sprocket wheel. In apparatus of this type. the sprocket wheel 1 is ordinarily rigidl secured to its shaft. In a still further modification of my invention, the lower sprocket wheel may be rotated at a greater speed thanthe upper sprocket 59, between the web-tensioningsystems, may be entirely omitted, and the sound may be, in this case, taken-off as the film moves between an optical system and a photo-tube suitably disposed. For this modification of my invention, an optical system=having a small angular aperture is desirable.

Although I have shown and described certain specific embodiments of my invention, I am fully aware that many other modifications thereof are possible. 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.

I claim as my invention:

1. Web-advancing apparatus comprising resiliently mounted dentate means to engage a web, inertial means disposed adjacent to said dentate means, additional resilientl mounted dentate means to engage said we inertial means associated with said last named dentate means, and means disposed between said groups 'of inertial means and dentate means for supporting said web.

2. \Veb-advancing apparatus comprising dentate means to engage a web, inertial means disposed adjacent to saiddentate means, additional dentate means to engage said web, inertial means associated with said last named dentate means, and means disposed between said groups-ofinertia means and dentate means for'supporting said web.

3. Web-advancing apparatus comprising resiliently mounted dentate means to advance a web, inertial means disposed adjacent to said dentate means to be rotated by said web, additional resiliently mounted dentate means to engage said web and inertial means associated with said last-named dentate means to engage said web.

4. Web-advancing apparatus comprisingv resiliently-mounted dentate means to advance a web, inertial means disposed adjacent to said dentate means to be rotated by said web, additional resiliently-mounted dentate means to be rotated by said web and inertial means associated with saidlast-named dentate means to engage said web.

5. Web-tensioning apparatus comprising a shaft to be power-driven, a dentate roller resiliently coupled to said shaft, a'dentate roller to be film driven, and damping means associated with said first-named dentate roller.

6. Web-tensioning apparatus comprising a dentate roller to be power-driven, a dentate roller to be web-driven, damping means associated with said last-named dentate roller and a resilient coupling between said lastnamed dentate roller and said damp'ing means. I V

7. Web-tensioning ,apparatus comprising a dentate roller to be power-driven, a stud disposed adjacent to said dentate roller, a

a denfi'ate'roller to be web-driven and resiliently 0011 led to said sleeve.

8. eb-tensioning means including a plurality of dentate-rollers, certain of said rollers being resiliently mounted, and at least one of said resiliently-mounted rollers being adapted to be web-driven.

9. Web-tensioning apparatus comprising a shaft to be power-driven, dentate means resiliently coupled to said shaft to engage a web, a stud spaced from said shaft, a sleeve rotatably supported on said stud, dentate means resiliently coupled to said sleeve to engage said web, damping means associated with said sleeve, and a surface disposed between said stud and said shaft to support said web.

10. In film handling apparatus means for impressing a record on a film strip or for translating a record impressed on a film strip, means for supporting said film strip in the region of said impressing means or said translating means, means for advancing said film strip over said film-supporting means, means, including a resilient element, to cooperate with said advancing means and with said film strip to maintain said film strip in tensioned condition, and means including a. plurality of rollers to be film driven, said rollers having considerable inertia, to cooperate with said resilient element and said advancing means to maintain said film in uniform motion as it passes over said supporting means.

11. Web-tensioning apparatus comprising means for advancing a web, a dentate roller to be driven by said web as it is advanced, damping means to cooperate with said webdriven roller to resist the torgue applied by said web and resilient couphng means mechanically interposed between said dentate roller and said damping means to partially take up the force impressed on said web by the coaction of said web, said advancing means and said damping means and thereby to suppress irregularities introduced into said web by the coaction of said damping means and said-dentate means.

In testimony whereof, I have hereunto subscribed my name this 3 day of April 1931.

ELLWOOD W. REYNOLDS.

sleeve rotatably supported on said stud, and p

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