US2023065A - Motion picture apparatus - Google Patents

Description

Dec. 3, 1935. F. CONRAD ET AL MOTION PICTURE APPARATUS Filed May 1, 1930 2 Sheets-Sheet l INVENTORS yam A'TTORNEY Dec. 3, 1935. CONRAD AL 2,023,065

MOTION PICTURE APPARATUS Filed May 1, 1930 2 Sheets-Sheet 2 f INVENTORS W 12 1/. ATTORNEY Patented Dec. 3, 1935 PATENT OFFICE 2,023,065 MOTION PICTURE APPAR TUS Frank Conrad, Wilkinsburg, and Christian Aal borg, Pittsburgh, Pa.', assignors to Westinghouse Electric and Manufacturing Company, a corporation of Pennsylvania Application May 1, 1930, Serial No. 449,024

9 Claims.

Our invention relates to acousto-cinematographic apparatus and'has particular relation to 1 domestic equipments of this type.

The film that is used in a domestic machine is 5 not, ordinarily, the property of the owner of the machine but is supplied to him by a film-library to which he pays a certain rental for the use thereof. Since the domestic films, thus available to the consumer, are, in general reduced prints of the commercial films, it is possible for the owner of a domestic machine to see the films, that are available for his apparatus, at his neighborhood moving-picture house, by paying a nominal price of admission.

The rental that it is necessary to charge for the use of the films, and, consequently, the durability of the film is, therefore, an important fact to be considered in determining whether the domestic motion-picture venture will be a success or a failure.

The length of life of the film depends onits intrinsic strength and on the handling that it receives in the machine. Since the film per se has elastic properties that are far from satisfactory in this connection, it must be manipulated in the machines with considerable care,- which is enhanced by the presence of a photo-acoustic sound attachment on the machine.

On the other hand, it is highly doubtful that the owner of a machine will restrict its operation only to the mechanically skillful members of his family. It is, furthermore, certain that the whole domestic motion-picture venture will fail if the consumer is required to pay for film mangled by his machine. A domestic motion-picture machine, therefore, of the type that is substantially ,fool-proof and practically incapable of causing injury to a film, even when operated by a totally unskilled person, is highly desirable. Such ma- .40 chine should be self-threading, and the various component parts thereof should be so interrelated that the sequential operation thereof is automatic. v .1

Automatic-threading motion-picture machines 45 constructed according to the teachings of the earlier prior art with which we are familiar have generally required manual operation for the provision of a loop-reservoir and for the application of pressure on the film after it has been threaded.

50 In machines of this type, the loop-formers are openectand the gates are closed after the film is positioned, and'considerable damage is done to the film by careless operators who forget to provide for the loop-space beforeapplying power for t 55 the actual projection of the picture.

Machines constructed according to the teachings of the later prior art are equipped with auto-. matically operative loop-formers. 'It is obvious, however, that, to function properly, the automatic threading devices on machines of this type 5 provide, for an acousto-cinematographic ma- 20 chine, an automatic-threading system that shall be kept permanently lubricated and require no attention in this connection from the owner.

An ancillary object of our invention is to provide an acousto-cinematographic machine 25 wherein the power-transmission parts arekept in a permanent state of lubrication.

A further object of our invention is to provide an acousto-cinematographic machine capable of producing sound of a good quality. 3

Still another object of our invention is to provide for a cinematographic machine power-delivery mechanism and an intermittent movement that are silent and smooth in their operation.

More precisely stated, it is ancbject of our 35 invention to provide a simple and compact acousto-cinematographic machine capable of delivering entertainment of good quality, and one that shall be so nearly fool-proof in its operation as to require a minimum degree of mechani- 40 cal ability on the part of the operator.

According to our invention, we provide accustocinematographic apparatus wherein the powertransmission elements are disposed in a chamber through which a lubricating fluid is kept constantly circulating, We, further, provide for the apparatus, an automatic threading,device wherein the loop-formers and-gates are operated by the film as it is wound on the take-up reel and which is provided with a plurality of motivating shafts disposed within the power-transmission chamber. Finally, we provide, for the photo-acousto-attachment of the machine, a film-advancing mechanism that minimizes the distorting 'efiect in the A sound of the discrepancy between the perforament of the shafts or pins on which the thread- I ing guides and loop-formers are mounted and tion pitch of the film and tooth pitch of the sprocket.

The novel features that we consider characterictic of our invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment, when read in connection with the accompanying drawings, in which:

Figure 1 is a view, in perspective, of,an accustocinematographic machine constructed accord ing to our invention,

Fig. 2 is a view, in front elevation, showing the principal elements of the automatic threading device of the machine,

Fig. 3 is a view, in plan, showing the arrangethrough which they are motivated,

Fig. 4 is a view, in transverse section, of the sound gate of the machine,

Fig. 5 is a view, in transverse picture gate of the machine,

section, of the Fig. 6 is a view, in plan, of the power-transmission chamber of the machine without the cover,

Fig. 7 is a view, in front elevation, of the main drive shaft of the machine,

Fig. 8 is a view, in perspective, of the cover of the power-transmission chamber,

Fig. 9 is an exploded view of the intermittent- "movement devices of the apparatus,

Fig. 10 is a schematic view of a large and a small sprocket showing, in detail, the advantage of the large sprocket for photo-acoustic apparatus,

Fig. 11 is a schematic drawing to which reference will be made in explaining the derivation of an expression for the minimum diameter that a sprocket applicable to photo-acoustic work should have, v

Fig. 12 is a view, in section, showing the picture and :'sound optical systems,

Fig. 13 is a view, in section,.taken along line XIII-XIII of Fig. 6, and t Fig. 14 is a view, in perspective, showing a takeup reel used with the machine.

The apparatus shown in the drawings comprises a hollow casting I provided with a supporting web 3, onone surface 5 of which are mounted a plurality of movable and stationary guides constituting an automatic threading device.

A feeding web I, having a roll' of film 9 wound thereon, is positioned on a spindle I I that is rotatably supported on a bracket I3 with which the main casting I is provided. The free end of the film 9 is i'nsertedin an opening I5 of funnel shape into which the teeth H of a rotating sprocket wheel I9 are projected.

The film thus presented to the sprocket wheel I9 is grasped thereby and projectedagainst the wall of a loop-forming guide 2I that is pivotally supported on a pin 23 which projects into the cavity 25 of the casting I. Acting under the thrust of the sprocket wheel I9, the film further advances between an aperture plate 21 and a shoe plate 29 of a picture gate 3| that are separated from each other for threading purposes, as will be described presently.

Directly below the aperture plate, the film 9 is grasped by a plurality of intermittently moving claws 33 and is projected against the lower wall of a loop-former 35 that is riveted to a metallic plate which is pivotally supported on a stud 39 that projects through the casting I.

The lower loop-former 35 engages a metallic strip 4I that is slidably supported in the picture gate 3| and is equipped with a plurality of in- 5 clined fingers 48 to coact with the shoe-plate 29 to hold it in open position. When the loop former 35 is pivoted away from the gate 3|, as will be hereinafter described, the metallic strip 4| settles, under its own weight, to allow the shoe-plate 29 to assume an active position relative to the film.

. The film is restricted partly by the loopformer 35 and ,partly by a stationary guide 45 mounted on the surface 5 of the hollow casting I in proximity to the-loop-former, and, as it advances, under the combined action of the sprocket wheel I9 and the intermittent claws 33 and under the restraininginfluence of these guiding elements, its central line assumes, in their vicinity, the form of a skew curve of comparatively large radius of curvature.

From the lower loop-former 35, the film is projected between the aperture plate 41 and the shoe-straps 49 of a sound gate 5| that is parallel to the picture gate 3I but is horizontallydisplaced therefrom. The upper ends of the shoe;- strap 49 are fastened to a stud 53 that projects from the main casting I, and the lower ends are fastened to a stud 55 that is mounted on the plate 31 to which the lower loop-former 35 is riveted. As a result, the straps 49 are displaced relative to the aperture plate 41 by the pivoting motion of the, loop-former and, when the latter is in its closed position, the former is separated from the aperture plate, leaving a com- 35 paratively spacious channel through which the film may pass with facility.

After passing through the gate 5|, the film advances in the channel formed between the flanges of an idler 51 and a stationary guide 39, and its end is thrust into the path of the teeth BI of a second rotating sprocket wheel 63. It is grasped by the sprocket wheel 63 and is directed into the opening formed between a plurality of guides 65 andG'I where it passes over an idler 69, rotatably supported on a resiliently mounted bracket II, and is thrust into one of a plurality of slots, provided between the edges of a multiplicity of strips I3 which constitute the hub of the take-up reel I5, as will be presently described. The reel I5 is mounted on a spindle 11 that is driven from the prime mover 19 of the apparatus through a belt 8| and,,as it rotates, the film 9 is fastened thereto.

The guides 65 and 61, between the reel and the second sprocket wheel 63, are rigidly mounted on a plurality of pins 83 and 85 that project into the cavity 25 of the main casting I. I The pins are rotatably supported in bearings 81 and 99 and are pressed into a web 9| that is cast integral with the main supporting base I and into the faces of they base. .The guides are,

furthermore, pivotally movable relative to each other and, in moving, rotate the pins 83 and '85.

A bell link 931s rigidly fastened, at its center, to the pin 83 that is rotated with the upper guide 65, while a short stud 95, projecting from one arm 91 of the bell link 93, engages a lever 99' fastened to the lower guide 51 in a slot II. The remaining arm I93 of the bell link 93 is provided 7 with a second stud I05 to which the movable end of a coil spring IIl'I that is anchored to the main casting I in a stud I09 which projects inwardlytherefrom, is fastened.

It is seen that the bell link 93 may be rotated f from either of the guides -65 and 61 and, in rotating, it moves the remaining guide relative to the guide that is moved. Moreover, as the link 93 rotates, the stud I05, to which the spring is fastened, is moved from one side of the link center 83 to the opposite side thereofflthus causing the spring III1'to reverse the action of the coupling force that it exerts between the guides 65 and 61. The guides are thus locked in their closed positions when the movable stud I05, that supports the spring, passes above the pin 83 and are urged to their most divergent position when the stud passes below the pivot. I

The spring I01 is fastened near the end of the stud I95 and, near its central section, the stud is engaged by a slotted lever III. The lever III is fastened to the end of the pin 23 that supports the upper loop-former 2| at its remaining end, and, as it is moved by the action of the bell link 93, it rotates the pin 23 to cause the loopformer 2i to move relative to the lower film guide I lit in its proximity.

The. pin 85, to which the lower take-up-reel guide 61 is fastened, projects through the rear wall N5 of the main casting I and has mounted, on its projecting end, ashort toggle link l I1 that is coupled to a comparatively long lever M9 by a stud Ml, fastened therein; The lever M9 is slotted, at its lower end, and engages a crank link I23 that is pivoted on the pin 39, to which the plate 31, riveted to the lower loop-former 35, is fastened.

The lower loop-former 35 is thus actuated from the take-up-reel guides. A stud E24, projecting from the face 5, prevents the loop-former 35 from being excessively deflected when it is in its open position.

A spring 925, anchored in a pin I21 that projects from the rear wall II5 of the casting l, engages the pin M9 to couple the crank lever H3 and the long lever H9 and coact with the toggle link II1 to positively hold the links and levers in either of their extreme positions.

The automatic threading system may be manually closed, in preparation for the threading operation, in which case, it assumes the form shown in Fig. 1. It is opened by the action of the winding of the film 9-on the reel 15 and assumes the form shown in Fig. 2. It is to be noted that, when the threading arrangement once assumes a terminal position, a'positive force of definite magnitude "and duration is required to cause it to change its position.

The apparatus is driven, through a series of worms I3I, I33 and I35 and worm gear wheels I31, I39 and MI, from the shaft I43 of the prime mover 19 that projects lengthwise through the cavity and is rotatably supported inl bearings I45 pressed into the ends thereof. The "sprocket wheel 63 that pulls the film through the sound gate 5I, and the cam disc I41 that actuates the intermittent movement device and the shutter I49 are driven through the worms HI and I35 and gear wheels I31 and HI, nearest the two ends of the shaft I43, while the sprocket wheel I9, that delivers the film from the feeding-reel 1, is driven through the'central worm I33 and the gear wheel I39.

A conical plate I5I is centrallysupported on the intermittent shaft with. It rotates in a cavity I 55 disposed below the remaining surface of the power-transmission mounted in the first plate slot H15 and pin E13 coact to provide the ver- I53 and is rotatable there-- mission chamber and is inclined thereto. The fluid dripping from the plate lubricates the bearings and flows, under the action of gravity, into the cavity I 55 where it is again discharged by the conical plate I5I. The lubricant is thus cir- 5 vculated through the bearings of the moving mechanism.

The intermittent-movement device comprises a plate I59 whereon a second slotted plate I 6| is mounted to form a recess I63 therewith. A 10 lever I55, guided by a slotted stud I61, rotatably I 59, is disposed within the recess I63 in such manner that it is capable of sliding and pivoting therein.

The lever I65 is equipped with a slot I69 that 15 engages a cam pin I1I, projecting from the cam disc I41, and with a pin I13 that engages a cam slot I15, milled in the surface of the cam disc. It is actuated by the cams and, in moving, it actuates the claws 33 integral with an arm I11 20 that is rigidly fastened to its upper end. The cam ill and slot I89 coact to provide the horizontal movement of the claws 33, and the cam tical movement.

A cavity 919 is provided in the surface 5 of the casting i wherein the cam disc I41 rotates. The recess E53 is equipped with a,slotted cover l8I into which the cam pin I1I projects and through which the pin 113 protrudes. formed by the three plates I59, lBl and I8I and the lever i155 and the arm E11, is fastened to the face 5 of the casting l vis-a-vis with the disc I41 and, since the surfaces facing each other are accurately machined, the fluid lubricating the in- 35 termittent movement device is not exuded.

By reason of the fact that films ordinarily change in length, to varying degrees, when subjected to developing, fixing and ageing processes, it is not possible to exactly predetermine their 40 perforation pitch. Consequently, a discrepancy between the sprocket-tooth pitch and the filmperforation pitch generally exists, and the film cannot be advanced by an ordinary sprocket wheelat the constant synchronous speed that is neces- 5 sitated for satisfactory photo-acoustic reproduction. One solution of the problem thus arising, which is described in a copending application of C. R. Hanna and E. H. Greibach, ,Serial'No.

406,847, filed November 13, 1929, and assigned to Westinghouse Electric and Manufacturing Company, includes the use of a flexibly-driven pulling sprocket wheel and a flywheel.

We have found that, as the diameter of the sprocket wheel that is employed to advance the 55 fihn through the sound gate is increased, the angle through which it moves, before a film that is being engaged by a tooth settles from the top of the tooth to the base, is increased. In Fig. 10, the phenomenon is shown in detail and it is 60 seen that the tooth I83 of the small sprocket wheel I85 is displaced from the film a. considerably greater distance than the tooth 6| of the sprocket wheel 63.

The sprocket wheel has a pitch that is equiva- 65 lent to the largest pitch that the perforations of the film can possibly have. It is, furthermore, so disposed in the machine thatthe film leaving it is under tension. Such a sprocket wheel func-' The unit, thus 30 the sprocket wheel. The equalization takes place in the time interval occupied by the film in settling from the top of an entering tooth to its base and 1s, consequently, less abrupt for a large sprocket wheel than it is for a small sprocket wheeL' The, explanation has been applied here to a holdback sprocket wheel and the sprocket wheel used in the machine is of this type. However, the theory applies to a feeding sprocket wheel in which case the tooth pitch is made equivalent to the smallest film-perforation pitch that is possible in practice.

A mathematical expression for the minimum diamemr of the sprocket wheel required to yield the maximum period of adjustment may be derived by referring to Fig. 111, wherein: a

r is the radius of the sprocket wheel,

11 is the distance between two perforations of the film,

' h is the height of a sprocket-wheel tooth.

It is seen that.

where D is the diameter.

Hence the condition maybe expressed by the inequality D is greater than p iently mounted idler 69. Any further irregulari ties which may be introduced by the sprocket wheel, by reason of imperfect manufacture, are ironed out by the idler 51 between the sprocket wheel 63 and the gate 5 I 7 It is to be noted that the position of the resiliently pivoted bracket II varies over a considerable angle as the tension in the film is varied. Moreover, as is clearly evident, the bracket occupies an extreme position against the uppert'ake-up-reel guide 65 if the film is not engaged in the reel and hence is not tensioned.

By reason of the variation in the position of the idler 69, relative to its neighboring guides 65 and 61, it may be utilized as the operating element of a device for stopping the machine if the guides are opened, by accident, before the film becomes fastened to the reel.

Such a stopping device is clearlywithin the scope of our invention and, since the proper disposition of insulating blocks and connectors for a relay canbe accomplished by one skilled in the art without the exercise of invention, we have not unnecessarily complicated the specification by adding a detailed description of the feature.

The sound track and the picture rectangleare both illuminated from a single source. I81 situated in a housing I89 behind the main casting I. The beam illuminating the picture aperture is projected directly from the lamp I81 through an opening I9I situated in the lower section of the main casting I. The rays from the lamp are converged by a.,lens I93 situated within the opening I9I and areJefiected substantially at right angles. by a mirror I95 to illuminate a picture in the aperture. The picture is, in turn, projected upon a screen by a projection lens I91.

The sound aperture is illuminated by the indirect light reflected from a curved mirror I99. 5 I

The rays are further convergedby a lens 20I 1 situated in a second opening 293, parallel to the first, and then are bent at right angles by a second reflector 205 to illuminate the sound track on the film positioned adjacent to the aperture. 10

The illuminated sound-track is magnified by a microscope objective 2H and focused on a slit (not shown) behind which a photo-cell (not shown) is situated. I

The take-up reel comprises twoflanged 15 plates 209 which are stiffened by a plurality of indentati'ons 2H pressed therein and are separated by a plurality of curved metallic strips 13 that, are riveted to them to constitute the hub of the reel.

end of the film may be thrust. They are provided with teeth 2I3, on'one side, whereby the film is engaged in its pigforations when it has once entered a slit.

The reel is rotated in such direction that the I overlapping ends of the strips advance against the film. The film is thus bent back and bodily displaced perpendicular to itself when its end is once engaged in a slot in the hub. It is thus caused to coact with the upper take-up-reel guide 65 to actuate the moving parts of the threading arrangement.

Although we have shown specific embodiments of our invention, fully aware that many modifications thereof are possible. Our invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by. the spirit of the appended claims. w 40 We claim as our invention:

1. In acousto-cinematographic apparatus, a a picture gate, abound gate, means for advancing a film from a feed reel to said picture gate, means for advancing said film through said picture gate, and means for advancing said film from said sound gate ,to a take-up reel, in combination with guiding means disposed between said filmadvancing means and said gates, between said, gates and between said reels and said film-advancing means, the guiding means between said take-up reel and said film'-advancing means projecting the film onto said take-up reel .at a point such that the portion ofthe'film adjacent the take-up reel is moved transversely to itself immediately on engagement of the film with the take-up reel, and means to be actuated by the winding of the portion of the film-which is moved transversely when the film is engaged with said take-up reel. mechanically coupled to said guidlng means for moving all of said guiding means transverse to said film. I

2. In film-handling apparatus, an automatic threading device comprising means for advancing a film from a feed-reel to a gate, means for advancing said film through said gate, means and described certain for delivering said film to a take-up reel, means The strips 13 overlap each other, and an 20 I opening is provided between them wherein the we are the portion of the film adjacent the take-up reel in a direction transverse to itself immediately on engagement of the film with the take-up reel, said loop-reservoir-formin'g means being normally in a position such as to restrict the formation of a loop and to guide said film and said pressure-applying means being normally in a position such that the pressure is relieved and said film is permitted to pass through said gates with facility and said guiding means including an arm, to be actuated by the portion of the film, which moves transversely to itself while in said transverse motion, and means for mechanically coupling said arm to said loop-reservoir-forming means and said pressure-applying means, for actuating said loop-forming means to permit the formation of loops and for actuating said pressure-applying means to apply pressure, when said arm is so actuated.

3. In a film handling apparatus, an automatic threading system including a plurality of fixed guides through which a film is to be advanced, a plurality of movable guides normally disposed adjacent to said fixed guides to form channels with said fixed guides for restraining the movement of the film along a predetermined path, a take-up reel on which said film is to be wound after it is advanced through said channels, a plurality of arms normally disposed adjacent to each other and to said reel and forming a guiding channel therebetween to so guide said film to said reel that the film moves transversely to itself as soon as it engages the take-up reel, means to be actuated by the film as it moves transversely to itself, when it engages said take-up reel for separating said arms and mechanisms interconnecting said arms and said movable guides for mov-.

ing said movable guides away from said fixed guides when said arms are separated, thereby permitting loops to form in the film between said movable guides and said fixed guides.

4. In acousto-cinematographic apparatus, an

enclosure having a picture gate and a sound gate,

mounted on one surface thereof, the transverse center line of said gates being at substantially equal distances from a parallel edge of said surface and the longitudinal center lines of said gates lying in difierent vertical planes parallel to said surface.

5. In acousto-cinematographic apparatus a supporting wall having a plurality of film gates so-mounted on one surface that when a film is advanced through said apparatus it moves in one direction through one of said gates and in the opposite direction through another of said gates, said gates being displaced to each other in a direction transverse to said wall so that their,longitudinal center lines lie in diiferent planes parallel. to'said Wall, a source of illumination disposed behind the othersurface of said wall and means for projecting radiations from said source on the surfaces of said film in said gates to illuminate said surfaces.

ii. A film-moving and reeling apparatus adaptcd for acousto-cincmatographic apparatus comprising means for moving a film, a guide channel for said film having separable walls adapted in one relative position to provide a relatively narrow channel for the film in its desired operative position in an optical projection system and in another relative position to provide a substantially wider channel into which said film can be readily threaded, a take-up reel, means for guiding the film to the take-up reel in such manner that the portion of the film which is immediately adjacent to the take-up reel is moved transverse to itself when the film engages the take up reel, and means to. be actuatedby the last said portion of the film when it is moved transversely to cause said separable walls to move from their 5 last-named relative position to their first-named relative position immediately on the engagement of the film and the take-up reel.

7. Film handling apparatus comprising means for storing a film, means for advancing said film from said storing means, a plurality of fixed guides over which said film is to be projected, a plurality of movable guides normally disposed adjacent to said fixed guides and forming channels therewith to restrict the movement of the I jacent to each other and the terminals thereof adjacent to said take-up reel that a guiding channel for said film as it is projected onto said take-up reel is providedthat isof suchcharacter that the film moves transversely to itself as it engages the take-up reel, means to be actuated by one of said plates, when it is moved in a direction perpendicular to the other plate by the film in its transverse motion between the plates, as it is engagedby said take-up reel and advanced thereby, for actuating said positioning means to separate said plates and to permit the film to freely advance to said take-up reel and mechanisms coupling said plates to said movable guides whereby said movable guides are separated from the corresponding fixed guides by the separation of said plates and loops are permitted to form between said movable guides and said fixed guides.

8. Film handling apparatus comprising means for storing a film means for intermittently ad-AO vancing said film from said storing means, a fixed guide over which said film is to pass to said intermittent-advancing means from said storing means, a movable guide normally disposed adjacent to said fixed guide and forming a channel therewith to restrict the movement of the film along a predetermined path, another fixed guide over which said film is to pass after it has been advanced by said intermittent-advancing means, another movable guide disposed adjacent to said last-named fixed guide and forming a channel therewith to restrain the movement of' said film along a predetermined-path, a take-up reel on which said film is to be wound after it has been advanced by said intermittent-advancing means, a plurality of plates and means for normally positioning said plates adjacent to each other to form a channel therebetween and adjacent to said take-up reel whereby said film is guided by said plates to said take-up reel, means 6 to be actuated by said film as it is wound on said take-upreel for separating said plates to permit the free movement of the film, mechanisms coupling one of said plates to said first-named movable guide whereby when said plate is moved said 5 of said gates and in the opposite the type incorporating a'supporting wall having a plurality of film gates so mounted on one surface that when a film is advanced through said apparatus it moves in one direction through one through another of said gates, said gates being displaced to each other in a direction transdirection-

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