US1891225A - Motion picture film treating apparatus - Google Patents

Description

"Dea, 20, 19321 R. G. FEAR MOTION PICTURE FILM TREATING APPARATUS Filed Nov. 22 1929 LSQLZZS 2 Sheets-Sheet 1 llllllll'llllllllllll'llllllllllllll,llulnl -Z f li l' .Hilll l' I www,

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MOTION PICTURE FILM TREATING APPARATUS Filed Nov. 22, 1929 2 sheets-shew 2 Een PH @liga/e.

Patented Dec. 20, 1.7932

UNITED STATES RALPH G. FEAR, OF LOS ANGELES, CALIFORNIA MOTION PICTURE FILM TREATING- APPARATUS Application led November 22, 1929. Serial No. 408,989.

This invention relates to improvements in automatic film treating machines in which the film is subjected to immersion in chemical or aqueous solutions, and then is subjected to a drying process.

This invention has for its primary object to provide an improved and simplified apparatus for the treatment of film in the form of a continuous tape such as is used in motion picture photographic Work. Inasmuch as this invention provides a machine that is basicly different in theory and design from other types of developing machines, my invention Will be best appreciated When compared With the conventional developing machines now in use. The present type machines are designed upon the generally accepted theory that dry motion picture film, when subjected to immersion in an aqueous solution, stretches, and that such stretching is not uniform throughout the time that the film is immersed in the solution, and that furthermore when the film is Withdrawn from the solution and subjected to the drying action of air, it shrinks in a non-uniform manner until it is completely dry, and, that this shrinkage, due to the chemicals in both the base and immersion covering continues after the film has dried. Based upon the above theory, all developing machines now in comi mon use employ compensating means for allowing stretching and shrinkage of the film. Some of these means comprise compensating Weights arranged to take up slack or permit shrinkage in the film While others embody rollers having automatic braking means controlled by the tension in the film tape. All of these forms, however, entail gears, drive shafts and innumerable small moving parts to which the solution has access with deleterious consequences.

In my present invention embodying an automatic developing machine, the construction has been simplified in every possible Way. The design is distinguished from all other machines by its lack of gears` bearings, shafts, and compensating mechanisms, etc. The theory upon which my machine is designed is, first, that when the machine is first started there is a stretching of the film as it becomes thoroughly Wet. During the initial start of the run the bulk of stretching is distributed over approximately the first 100 feet of film and after that, although every foot of film that runs through the machine stretches, the stretch is a constant factor and as the rate of travel of the film through the machine during this period remains constant, no stretch compensating means are necessary after the first stretching. T have also found in actual practice that as the film passes through the developing processing tanks, there is a continual braking effect or drag exerted upon the film due tothe frictional drag of the solution against the film. rThis effect operates to at all times exert tension upon the film tape which automatically compensates for any slight accumulation of slack that may occur after the compensating arrangement has been passed. Furthermore, as the film is fed through t-he machine into the dry box, the film begins t-o shrink. This shrinkage, however, does not occur until such time as the emulsion on the film starts to dry. From that time until the film leaves the dry box, the shrinkage is particularly constant. Tt Will be understood, therefore, that the greater shrinkage accumulates as the film approaches the take-off end. It, therefore, becomes another object of this invention to provide means for automatically compensating for the stretching of a film tape under Wet treatment and in the reverse order to permit shrinkage of the film under dry treatment.

It is a noteworthy feature of my invention that advantage is taken of the fact that substantially the entire stretching and the entire shrinking of a film under Wet and dry treatment, respectively. takes place Within a certain portion of the film and that the frictional drag placed upon the film caused by passing through an aqueous solution is utilized to automatically compensate for any slight slack that may accumulate in the Wet treatment of the film after it has passed the compensating arrangement.

Briefiy stated, my invention includes a series of driving rollers having equal outside diameters and variable internal diameters, said rollers being loosely mounted upon a shaft of uniform diameter. The rollers are provided with holes of greater diameter than the diameter of the shaft and for purposes of varying the peripheral speed of said rollers, the internal diameters of the holes vary. In the arrangement for compensating for slack in the wet treatment the internal diameters of the rollers vary in a symmetrically decreasing ratio from the initial roller inward until the bulk of the stretching has taken place, at which time the internal diameter of the rollers becomes uniform and may be called a basic diameter. The rollers from this point onward are of basic internal diameters and continue as such until the compensating means for shrinkage is encountered whereupon the internal diameters of the rollers symmetrically increase until the take-off roller is encountered. It is obvious that the rollers, being loosely mounted upon the shaft, are driven by v irtue of their weight upon the shaft and theoretically there is no friction involved unless the rollers slip.

It Will be understood from this arrangement that the rollers do not revolve at the same rate of speed as does the drive shaft, and that by thus graduating the size of the holes within acertain portion of the rollers, li am enabled to vary the peripheral speed of that portion of the rollers. It, therefore, becomes evident that, at the point in the drying box, for example, when the film starts to dry and, consequently, shrink, if the internal diameter of the rollers begins to increase vand progressively increases up to the take-o end, that no two of the rollers at the take-off end revolve at the same speed, the consequence of which is to drive the film at the take-off end with a constantly decreasing speed which operates to compensate for shrinkage of the film. The reverse of this arrangement when employed, as before stated, at the beginning of the film run, operates in a reverse manner to compensate for stretching of the film.

It is a further object of this invention to provide a take-off mechanism at the drying box end of a unique and novel design adapted to automatically maintain a constant film tension upon the film that is being taken up by a take-up reel.

Several of the major advantages of my invention are briefiy set forth as follows:

Fina-The film progresses continuously in a substantially spiral path through the apparatus;

Second-Only one drive shaft is necessary to operate the entire machine;

Third-Gears, belts, and pulleys are eliminated;

F martn-No mechanism or frictional compensating devices are used to compensate for any variation of film length; A

Fifth-The rollers are non-frictionally driven by the drive shaft and the only time any friction occurs in the mechanism is when the rollers slip Statie-The frictional drag of the aqueous solutions on the film is utilized to Vautomatically compensate for any slight slack that may develop in the machine between the compensating means; and

Seventh-The machine is designed upon the assumption that after the machine is star-ted and the film is thoroughly wet, and the initial stretch has taken place in the film, there is a constant velocity imparted to the film throughout the machine until it has passed through the drying cabinet to such a point at it begins to dry and that then there is a constant decrease in the film speed until it is finally taken up by the take-up reel.

Other objects and advantages will be best appreciated in connection with the drawings wherein a preferred embodiment of my invention is illustrated by way of example and in which Fig. 1 is an enlarged view showing the single tank arrangement and the manner in which the driving and driven shafts are supported;

Fig. 2 is a section on the line 2-2 of Fig. 1;

gig. 3 is a section on the line 3-3 of Fig. 1; an

Fig. 4 is a more or less diagrammatic view of my entire developing machine showing all the mechanism necessary for the continuous process of developing and drying film.

In the drawings, and particularly Fig. 1, have shown my invention generally designated at D as embodied with a tank A, which may be the conventional developing or treating tank of the usual order. A film B is run through the tank A in the usual manner, and is threaded over pulleys 11 and 12 suitably mounted on a superstructure C above the tank A. The film B is then twisted through an angle of 90o and is threaded over a roller 13 loosely mounted upon a shaft 14 in the lower part of the tank A. It is to be understood that a plurality of rollers 13 are mounted on the shaft 14. The shaft 14 in turn is suspended in the tank A by means of rods 15 carrying a hub 16, into which the shaft 14 is suitably mounted. The rods 15 are suspended in any convenient manner from the superstructure C above the tank A. The film B is returned from the roller 13 to a roller 17 mounted upon a shaft 18. The shaft 18 is driven by any suitable means not shown and supplies the power to drive the roller 17 of which there are a plurality loosely mounted thereon. These rollers are driven by the weight they exert upon the shaft 18. It is evident that the shaft 14 may be driven in any suitable manner in conjunction with the shaft 18, or that, if preferable, the rollers may revolve thereon. The rollers 17 being a part of this invention, will be more fully described hereinafter. The lm B continues around the rollers 13 and 17 consecutivel describing a spiral path through the tank and is taken out of the tank A. and over a roller 19 suitably moun-ted on the superstructure C. T he film may then descend into another treating tank, but in so far as the structure is concerned, any other unit may be identical with the one justdescribed. As a means of holding the film B within the conventional rollers 13, small auxiliary rollers or guides 20 are provided and are carried upon a shaft 21.

it is obvious, that unless some means is provided for compensating for the slack incidental to the wet treatment and for the tension occurring in the film during the drying operation, the apparatus eventually becomes inoperative. This is appreciated since the means of carrying the film through the tank reside in the shaft 18, which in turn imparts a rotation to the rollers 17. it, therefore, becomes apparent that if the rollers 17 are rotated at the same speed throughout the length of the shaft 18, slack will accumulate in the wet tank, while tension sufficient to eventually break the film will be created in the drying box. Therefore, in order to compensate for this slack and apply sufficient tension upon the film to hold it in driving contact with the driving rollers 17, I have devised a unique method of causing the rollers 17 at the start of the run to progressively increase in speed. As a means of accomplishing this, l make the first few rollers 17 with larger holes than are subsequently used throughout the entlre machine. 'll`he rollers, in this instance, are hollow and are formed with substantially equal outside diameters, but have holes that proare equal to what l call a basic holev diameter.v

rl`his basic hole size is maintained throughout the machine until the point is reached in the dry box where the film starts to dry. From this point on, the holes in the rollers progressively increase in diameter to the end ofthe machine. It will be understood that this variation in hole sizes applies only to the film driving rollers.

it will be appreciated that by thus providing hollow rollers of substantially equal eX- ternal diameters and of different internal diameters, and by mounting these rollers upon a shaft of equal diameter throughout its length, such rollers will have variable effective driving radii and upon rotation of the shaft, will rotate at various speeds. My invention utilizes this idea and it is to be understood that the rollers 17 are loosely mounted upon the shaft 18 and rely solely upon their weight upon the shaft for obtaining rotative movement therefrom. Therefore, it is obvious that a progressively increasing or a decreasing peripheral speed of the rollers is obtainable wherever deemed necessary.

In Fig. 2, l have shown substantially the form of an initial roller, and in Fig. 3 l have shown a final roller designed to cooperate in taking up the slack produced in a film under wet treatment. lt is to be understood that only the first few rollers interposed on the entering end are so graduated and that the rollers are of uniform internal and external diameter through the machine until a point in the drying cabinet is reached where the film starts to dry. From this point on, the internal diameters are arranged in the reverseA orde-r and increase in size.

A noteworthy feature of this arrangement is the fact that by proper designing, a series of rollers may be provided that exactly compensates for the stretching and the shrinking of the film under both the wet and the dry treatment. However, it is also to be appreciated that in cases where exact compensation is not precisely met, the rollers, due to being loosely mounted, may automatically compensate for the slight remaining difference by slippage. lt is obvious that this arrangement of the rollers with respect to the travel of the film produces an apparatus capable of compensating forthe shrinkage and/or stretching of films under treatment.

in Fig. 4, l have shown a somewhat diagrammatic view of my invention as it would he embodied in a continuous process of wet treatment and the subsequent drying of a film. In the tanks K, L, M, and N, the treatment is assumed to be of a wet nature, and in the boxes P and R, the treatment is of a drying nature, consequently, my devices indicated at D are arranged to produce an initial tension on the film, whereas my devices shown at D are arranged to compensate for shrinkage of the film, during drying. The rollers between D and D are of uniform diameter and no allowance is made for compensation. It is to be noted that thefilm is fed into the apparatus in the usual manner and follows a conventionally continuous passage through the boxes K, L, M, and N, and passes into the dryers P and R, wherein it follows the usual spiral path until it emerges over the roller 25. The roller 25 is mounted on an arm 26, which in turn is pivoted on the pin 27 and carries at its outer end a roller 28 arranged as an idling roller upon the belt 29, which drives the reel 30, and in turn is driven by a pulley 31. The pulley 31 is arranged to be driven by the shaft 32, which, by means of common expedients, not necessary to describe, is driven by the same means that operates the film through the boxes. The arrangement of the pivoted arm 26 is recognized as providing means of controllably driving the reel 30 in response to the tension in the film B.

As stated before, for convenience, in construction, the lower shaft as shown in compartments P and R in the dry box is the driven shaft. If the take-up reel 30 fails to function, the film B is no longer pulled by the reel and slack develops. rIhis causes the film in turn to drop away from the lower shaft and as a result continual slack will develop in the dry box until the film no longer feeds through it.

Inasmuch as tension is required on the film in order that it mayv be driven through the drying box, it is obvious that if reel 30 stops functioning, the entire strip of film will stop passing through the drying machine and the machine will become inoperative.

Although I have shown my invention in conjunction with al particular piece of apparatus, I am aware that it is equally adaptable to other types of apparatus, and I, therefore, intend that this disclosure shall include all applications of my invention that come within the scope of the disclosure and the essence of the invention as expressed in the appended claims.

I claim as my invention:

l. In a film treating apparatus, means for driving a film through said apparatus, said driving means being non-positively operated at progressively changing angular velocity.

2. In a film treating apparatus, means for driving a film through said apparatus, said driving means being non-positively operated at progressively increasing angular velocity to compensate for expansion in the film.

3. In film treating apparatus, means for driving a film through said apparatus, said driving means being non-positively operated at progressively decreasing angular velocity to compensate for shrinkage in the film.

4. In film treating apparatus, means for driving a film through said apparatus at progressively changing speed, said means including a power driven shaft and a series of hollow rollers loosely mounted thereon, the rollers of said series having substantially equal outer diameters and different internal i diameters.

5. In film treating apparatus, means for driving a film through said apparatus at progressively changing speed, said means including a power driven shaft and a series of holy 7. In a film treating apparatus, means for driving a film through said apparatus, said means including spaced parallel shafts having a series of rollers loosely mounted thereon and adapted to rotate with said shaft; and means for driving one of said shafts to rotate said rollers mounted thereon; the rollers on at least one of said shafts having substantially equal outer diameters and different internal diameters.

8. In a film treating apparatus, means for driving a film through said apparatus, said means including spaced parallel shafts having a series of rollers loosely mounted thereon and adapted to rotate with and at a different angular speed from said shaft; and means for driving one of said shafts to rotate said rollers said rollers having substantially equal outer diameters and progressively increasing internal diameters.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 13th day of November, 1929.

RALPH G. FEAR.

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