US1733557A

US1733557A - Film-retaining roller

Info

Publication number: US1733557A
Application number: US286829A
Authority: US
Inventors: Pfannenstiehl Harry
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1928-06-20
Filing date: 1928-06-20
Publication date: 1929-10-29
Anticipated expiration: 1946-10-29

Description

Oct. 29, 1929. H. PFANNENSTIEHL FILM RETAINING ROLLER Filed June 20, 1928 ,4 TTORNE) Patented Oct. 29, 1929 PATENT OFFICE BARRY PIANNENBTIEBL, OI IOIlNTAIN LAKES, NEW JERSEY, ABSIGNOB TO BELL or NEW 2on1:

TELEPHONE LLBOIBATOBIES, INOORI'OItATED, 01 NEW YORK, N. Y., A CORPORATION rnunnrnnine Roxanna Application ma June so, 1925. Serial 10.38 m.

This invention relates to improvements in film feeding devices, as for example, those 5 It is the object of this invention to pro used in motion picture projection machines and cameras. a

. vide anim roved-form of film retaining vention to rovide a mounting for, a film reroller whic sprocket to prevent the film losing engagement with the drivin teeth of said s rocket.

It is more specifica ly the object o the int'aining ro er which shall be compact and capable of use in a minimum of space and.

which shall be easy of and positive in operation. v

A feature of the invention is the use of a manually rotatable shaft for mounting the retaining roller, said shaft being so mounted that its continued rotation in one direction moves said roller into and'out of engagement with said driving s rocket.

. A further feature of t e invention results from the use of a latching device to hold said roller in either its in or out position. Said device alsov permits rotation of the control shaft in one direction only.

It may also be noted that the control shaft is latched in such a manner that the pull of the film in passing between the driving sprocket and the retaining roller cannot tend to force the retaining roller out of engagement with the sprocket. I

A morecomplete understanding. of the invention may be had from a consideration of the following detailed description, reference being had to the accompanying drawcooperates with a driving a main shaft 3, to which a cham-driven v sprocket wheel 4 is secured by means of a set screw5. Secured to the shaft 3 is a roller 6 provided with toothed sprockets to engage w1th the film perforations and thus impart movement to the film. The lower part of the housing is drilled to receive a shaft 7 which is secured by means of a set screw 8. On this shaft is mounted an idler roller 9.

This idler roller is free to rotate on the shaft 7 and is held in position b means of a thrust washer 10, which is suita 1y secured to the shaft 7. Rotatably mounted in the main housing 1 is a shaft 11, which may be best seen by reference to Fig. 3. Aflange 12 holds this shaft from axial motion in one direction. A shaft 13 is formed inte ally with the shaft 11, but is eccentric with respect thereto. A retaining roller 14 is mounted so as to be freely rotatable on the shaft 13. The retaining roller is provided with double flanges at each end and when in operative position presses the film against the driving sprocket 6. The teeth of this sprocket at such time fit in between the flanges of the idler 14 so that the sprocket holes on the film are firmly held in engagement with the sprocket teeth of the driving roller and the film has no opportunity to slip. In order to move the retaining roller into and out of engagement with the driving sprocket a knurled lmob 15 is secured to the shaft 13 by means of a set screw 16, which engages a flattened portion of the shaft 13.

In order to latch the retaining roller in either of two positions a spring pressed ball 17 is provided and cooperates with notches 18 one or the other of the notches when the bearing 11 has been rotated into Suitable position. Tension on the spring 20 may be regulated by means of 'a set screw 21 threaded into the bearing portion of the mounting plate 1. A guard flange 22 (best seen in Fig. 2) is secured to the mounting plate by means of screws 23 and has an extension 24: which sweeps the surface of the sprocket roller between the sprockets to prevent'any tendency of the filmto wrap itself around the sprocket in case of film breakage. An oil-cup is indicated at 25.

Referring now to Figs. 4 and 5, a detailed description of the arrangement whereby the retaining roller may be latched either in engagement with or out of engagementwith the driving sprocket will be made.

Fig. 4 shows the retaining roller in engagement with the driving sprocket. It will be seen that the spring pressed ball 17 is cooperating with notch 18 in the bearing 11. If now an attempt is made to rotate shaft 11 in a counter-clockwise direction the shoulder of notch 18 resses against the surface of ball 17 at a point above its center. The result is to tend to force the ball downward and thus firmly hold the bearing 11 against rotation. The rotation of the sprocket roller 6 is as indicated by the arrow. As a result, it is clear that the pull of the film on the roller 14 will tend to cause a counter-clockwise rotation of the bearing 11. Since the bearing is securely latched against counter-clockwise rotation the passage of the film under the pull of the driving sprocket 6 can have no tendency to force the retaining roller out of engagement with the sprocket.

Further inspection of Fig. 4; will show that bearing 11 is free to rotate in a clockwise direction under the influence of knurled knob 15. When moved in a clockwise direction the lower shoulder of the notch 18 strikes the surface of ball 17 well below its center and therefore can force the ball up into position to ride on the peripheral surface of bearing 11. It is further obvious that continued rotation of bearingll will cause shaft 13 to move around the central axis of shaft 11. Thus, clockwise rotation of bearing 11 moves shaft 13 upward and to the right in an are centered about the axis of bearing 11. As shaft 13 moves upward and to the right the retaining roller 14 is carried out of engagement with the driving sprocket 6 and continues to move away from said driving sprocketuntil notch 19 is brought into registration with the ball check 17. When bearing 11 has revolved through 180 the shaft 13 and roller 14 will be at a maximum distance from the driving sprocket. In this way maximum clearance is provided for the convenient threading of the film through the machine and onto a sprocket 6. It is believed to be obvious that the bearing 13 is latched against countermanner identical with that previously described in connection with the in position. Fig. 5 shows the retaining roller latched in its out postion.

In order to bring the retaining roller back into engagement with the driving sprocket, the bearing 11 is again rotated in a clockwise direction by means of knob 15. A revolution of 180 will cause the roller 14 to complete a movement downward and to the left and then upward and to the left until the roller has returned to the position shown in Fig. 4.

What is claimed is:

1. In a film feeding device, a driving sprocket, a retaining roller for holding a film against said sprocket, a shaft on which said roller is rotatably mounted, a bearing in which said shaft is eccentrically mounted, and means to rotate said shaft in said bearing to move said roller into and out of engagement with said sprocket, the direction of the rotation for both operations being the-same.

2. In a film feeding device, a driving sprocket, a retaining roller for holding a film against said sprocket, a shaft on which said roller is rotatably mounted, a bearing in which said shaft is eccentrically mounted, means to rotate said shaftin said bearing to move said roller into and out of engagement with said sprocket, the direction of the rotation for both operations being the same, and latching means to hold said roller in operative postion with respect to said sprocket.

3. In a film feeding device, a driving sprocket, a retaining roller for holding a film against said sprocket, a shaft on which said roller is rotatably mounted, a bearing in which said shaft is eccentrically mounted, means to rotate said shaft in said bearing to move said roller into and out of engagement with said sprocket, the direction of the rotation for both operations being the same. and latching means to hold said retaining roller in operative position and to prevent rotation of said shaft in a non-operating direction.

4. In a film feeding device, a driving sprocket, a retaining roller for holding a film against said sprocket, a shaft on which said roller is rotatably mounted, a bearing in which said shaft is eccentrically mounted, means to rotate said shaft in said bearing to move'said roller into and out of engagement with said sprocket, the direction of the rotation for both operations being the same, and I HARRY PFANNENSTIEHL.