US1614214A

US1614214A - Means for supporting and driving films

Info

Publication number: US1614214A
Application number: US700732A
Authority: US
Inventors: Steiner Oscar
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1924-03-20
Filing date: 1924-03-20
Publication date: 1927-01-11
Anticipated expiration: 1944-01-11

Description

Jan.

1,614,214 0. STEINER MEANS FOR SUPPORTING A ND DRIVING FILMS Filed March 20,\ 1924 InVe1'1tOTI Oscar Steiner", by M H is Attorn ey Paren al Jan. 11, 1927.

U ED STATES PATENT OFFICE.

osoAn srnmnn,

OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO GENERAL ELEC- TRIO COMPANY, A CORPORATION OF NEW YORK.

(MEANS FOR SUPPbItIING AND LRI'VING FILMS.

Application filed March 1924. Serial No. 760,732.

My" invention 7 relates to that class of mechanism in which a photographic strip or film is caused to move past a screen having an opening through which light rays may .15 pass to the film and an object of my invention is to provide an improved means for supporting v the film and giving it anniform movement close-to the screen.

w It is Well known thatfilms bearing moving 10 picture records are fed through the motion picture machines-in common use in an intermittent manner, the necessary movement being communicated to the film by means of toothed wheels which engage in a series of 5 openings extending along each margin of 'L-the filmt When a sound record has been made upon the film it has been found most expedient to move the film at a substantially uniform rate and consequently when the 0 record is to be reproduced the film should again be moved at a uniform rate.

It has been found that where the film bearing the 'sound record was moved through the sound reproducing apparatus by the usual toothed wheel means the reproduced record was accompanied by an objectionablesound which was attributed to a vibration given to the film by the teeth of the driving wheels enso gaging in the openings in the film. In accordance with my invention I effect a uniform movement of the film. by causing it to engage the periphery of a smooth driving pulley. The pulley isconstructed with a true cylindrical surface so that the film in lying snug against the surface can be caused to run very close to a light screen without actual contact therewith. For increasing the adhesion of the film to the cylinder and to prevent possible slipping of the film, I

proyide one or more idlers to bear against that portion or'portions of the film having theusual sprocket wheel openings, the surfaces of the idlers being of relatively soft I material so that those portions coming opposits the openings'in the film may push through and engage the surface of the drive pulle I I My invention will be better understood from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the ap pended claims.

In the drawing Fig. 1 is a side view of a construction illustrating an embodiment of my invention; Fig. 2 is a fragmentary cross sectional view drawn to a larger scale and taken on the line 2-201? Fig. 1; and Fig. 3 is a fragment of'Fig. 2 drawn to. a still larger scale.

Referring to the drawing, aframe 1 provides bearings for the two film reels 2 and 3, the film 4'being wound from the former to tlfie latter during the operation of the ma- 0 me.

The upright portion 5 of the frame 1 forms a bear-ing for a shaft (not shown) carrying the pulley 6 and a cylinder 7 of transparent material preferably glass. Within the cylinder 7 is located the photoelectric cell Shaving a window 9 for receiving lightrays. The'outer'surface of the cvlinder 7 is made true and concentric with :thefaxis of rotation and on this surface rests the film ithe same being driven by the cylinder. Idlers 10 and 11 are shown for causing the film to engage as'large a proportion of the circumference ofthe cylinder as is practicable and-to direct the film through suitable openings in the frame 1 At a point opposite the window 9 of the photoelectric cell the frame 5 is provided with an opening 13 behind which is shown a screen 14. This screen has a'narrow slit 15., preferably about 1 mil in width, arranged transversely of the film through which light from a suitable source (not shown) may pass to the cell 8 under the control of the .may be given a relatively large mass.

In order'that there may be sufficient traction between the glass cylinder 7 and the film 4, which may be the standard celluloid film commonly employed in the production of moving pictures, I have provided a pair of idlers 17 having tires of soft material such as rubber which are arranged to bear against opposite margins of the film and press it firmly against the cylinder. Advantage is taken of the two marginal rows of sprocket wheel apertures with which standard films are provided in that portions of the soft tires of the idlers 17 push through those apertures to the cylinder surface beneath, see Fig. 3, and in so doing constitute in effect driving teeth, the adhesion between rubber and glass being much. greater than that between celluloid and glass. For rotating the winding pulley 3 to take up the film as it comes from the driving cylinder 7 the motor 16 is shown connected to the pulley 3 by a belt 18. This belt, however, is loose and the ratio of the diameter of the pulley on the motor to that of the pulley on the reel 3 is so chosen that the reel 3 always tends to run faster than is needed and the belt is constantly slipping. This feature being no part of my invention and being well known in the moving picture art-will not be described further.

It is essential with a device of this nature that the film pass very close to the screen 14 but to prevent scratchingof the film it is important that the film shall not have frictional contact with the screen or with any guiding means which might scratch its surface. ,By the use of my device the film can be made to pass with the desired closeness to the screen and at the same time avoid contact with anything which might scratch it. Moreover, by causing the film to be driven through the glass cylinder 7 and the cooperating idlers a positive movement free from slippage is obtained in a simple manner and without the disadvantages arising from the use of sprocket wheel drives.

While I have described only one embodiment of my invention, I do not wish to be limited to the particular form shown and described as it will be apparent that many modifications therein may be made without departing from the scope of my invention as set forth in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States 1. In a device of the character described, a screen having an opening therein, a rotatable cylinder over which a continuous length of film is adapted to pass arranged opposite said opening, and means for holding the film snugly against the cylinder as it passes thereover including a member arranged to engage simultaneously the film and the cylinder. 1

2. In a device of the character described. a screen having a narrow opening therein, reels adapted to carry a photographic film, a transparent cylinder for supporting and moving said, film in close proximity to said screen at said opening and a photoelectric cell arranged within said cylinder adapted to be affected by light rays passing through said opening and said film. i

3. In a device of the character described. a screen having a narrow transverse opening therein, a glass cylinder for supporting and moving a photographic film past the opening in said screen, a winding reel and an unwinding reel for said film, a photoelectric cell within said glass cylinder, and means for rotating said ing reel. 7

4. In a device of the character described employing a photoelectric film, driving means for said film comprising a pair of wheels between which said film passes, one of said wheels having a soft, resilient peripheral surface, adjacent portions of which cylinder and said windsimultaneously engage said film and the surface of said other wheel.

5. In a device of the character described employing a film having a series of marginal apertures therein, means for moving said film, said means comprising a pair of wheels between which said film passes, one of said wheels having a smooth resilient surface, portions of which are adapted to project through said apertures into contact with the other wheel.

6. In a device of the character described employing a film having a series of marginal apertures therein, a cylinder for supporting and moving said film, means for rotating said cylinder and means for preventing said film from slipping on said cylinder comprisinga roller having a soft, resilient surface adapted when pressed against said film to push through said apertures and engage the surface of said cylinder.

In witness whereof, I have hereunto set my hand, this 14 day of March, 1924.

OSCAR STEINER.

Certificate of Correction. Patent No. 1,614,214, granted January 11,1927, to

OSCAR STEINER.

It is hereby certified that error appears in the printed specification of the abovementioned patent requiring correction as followsz-Page 2, line 76, claim 4, for the word photoelectric read photographic; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 22d day of February, A. D. 1927.

[seen] J. MOORE, Acting Commissioner of Patems.