US1241869A - Moving-picture machine. - Google Patents

Description

R. W. MARTIN.

MOVING PICTURE MACHINE.

APPLICATION FILED SEPT. B. l9l5.

R w yfiVENTOR n-ronuzv WITNES I direction shown by the arrow.

RALI H W. MARTIN, OF BELLEVUE BOROUGH, PENNSYLVANIA.

MOVING-PICTURE MACHINE.

To all 'wlwmc't may concern:

Be it known that I, RALPH W. MARTIN, a citizen of the United States, and residing in the borough of Bellevue, in the county of Allegheny and State of Pennsylvania, have invented or discovered new and useful Improvements in Moving-Plcture Machines,

I of which the following is a specification.

My invention consists of new and useful improvements 1n pro ectors or movmg p1cture machines.

More particularly, my invention comprises novel means for imparting intermittent travel to "the. film as it passes the framing gate,and also a new and improved shutter mechanism.

Novel features of construction and arrangement of parts will appear from the "omitted for the sake of clearness; Fig. 2

j is a diagrammatic view illustrating the relative rotary movements of the constant and variable speed shafts,.and Fig. 3 is a similar view illustrating the relative movements of the variable speed sha'ftand the rocking shaft." v r The following is a detailed description of the drawings, reference being first had to Fig. I.

A represents the frame or bed plate of the projector provided with two pits 1 to give clearance for the crank arms and wrist pins.

2 is a forwardly extending bracket mounted on the bed and provided with transverse journal boxes 3 and 4, and a third journal box 'hon the angular extremity of said bracket. t

B is the power shaft, journaled in box 3 and'rot'ated by any convenient means, as

hand crank 6, at substantially constant speed and in the direction indicated by the arrow.

7 is a relatively large gear rigidly mounted on the other end of shaft B.

8is,a smaller gear, meshing with and in the ' rearfof gear 7, and 9 is a short shaft upon one end of which said gear 8 is rigidly 1 mounted and which is journaled in a box 10 on the bed A; It is evident that shaft 9 willbe rotated at constant speed in the Specification of Letters Patent.

Patented Oct. 2, 191 '7.

Application filed September 8, 1915. Serial No. 49,510.

The other end of shaft 9 is provided with a crank arm 11 provided with a wrist pin 12. Clearance is provided for said crank arm and wrist pin by one of the pits 1.

13 is a second short shaft mounted in journal box 1 1 on bed A and in a parallel plane with but to the rear of shaft 9. One end of shaft 13 is provided with a longitudinally slotted crank arm 15 whose slot is engaged by the wrist pin 12.

It is evident that the rotation of the shaft 9 at constant speed will result in the rotation of the shaft 13 at variable speed in the same direction.

Referring now to Fig. 2, the smaller circle represents the path of rotation of the wrist pin 11 whose center is the shaft 9, while the larger circle represents the path of rotation of the crank arm 15 whose center is the shaft 13, the dotted linea between the centers 9 and 13 representing the distance between the axes of said shafts. The length of said line must necessarily be less than the radius of the smaller circle but may be any length less than the latter, the length of the line controlling the variation in the speed of rotation of the shaft 13. v

The smaller circle is shown divided into equal arcs to indicate constant speed of rotation while thelarger circle is divided into an equal number of arcs of varying length, in radial alinement with the arcs of the smaller circle, to indicate the variationsin speed.

The other end of shaft 13, is provided with a crank arm 16 having a wrist pin 17 for which clearance is provided by the second pit 1. The crank arm 16 is shown extending in the opposite direction from that of crank arm 15 of the same shaft but may be set at any angle that may be desired. The maximum of effect, however, is produced by, opposing said crank arms, as shown.

1.8 is a third short shaft journaled in a box 19 on the bed A in a parallel plane with shafts 9 and 13 but in advance thereof. One end of shaft 18 is provided with a longitudinally slotted crank arm 20 whose slot is engaged by the wrist pin 17. It is evident that the rotation of the shaft 13 will result in imparting a rocking motion to the shaft 18. j

Referring now to Fig. 3, the circle indicates the path of the wrist pin 17 its variable speed being indicated by the arcs of difi'erent length marked on the circle.

It will be noticed that the arcs on the circle in Fig. 3 vary in a manner reverse to those in the large circle in Fig. 2, owing to the fact that the position of the crank arm 16 is the reverse of that of crank arm 15..

18 represents the rocking shaft and the dotted line Z) indicates the distance between the axes of the two shafts, said distance being necessarily greater than the radius of the circle to produce the rocking motion in the shaft 18. v i

The tangential lines and d, extending from the axis of the shaft 18 represent the upper and lower limits of the rock of the crank arm 20. While the wrist pin 17 is rotating in the direction of the arrow, it is evidentthat the upward movement of the crank arm 20 is more rapid than its down ward movement. I

21 is a crank arm on the other end of the rock shaft 18, shown set opposite to the dog arm 24 intermediate of the endsof the latter.

'25 is the framing lever mounted intermediate of its ends on the bed A by means of athreaded stud 26 extending horizontally from the latter. Said framing lever is held rigidly at any desired angle by means of a clamp nut 27 screwed upon the stud '26, against the framing lever.

The forward end of the framing lever is provided with a pivot pin 28 Whichengages the pierced rear end of the dog arm 24.

The forward end'of the dog armfle is provided'with the usual cylindrical dog C. l

D is the film sprocket, rigidlymounted on thepower shaft B parallel withth'e dog C.

E is the film passing down through the gate F, under the dog C and over the sprocket D. G represents the lens. i

"The operation of the device is as follows:

The shaft B is turned at constant speed to rotate the gear 7 in the direction of the arrow, imparting rotation at constant speed in shaft 9, rotation at variable speed in shaft, 13, and a rocking motion in shaft 18, causing the dog C to be alternately raised and lowered, the speed of depression being greater than that of elevation. Meanwhile, the sprocket D is rotated, drawing the'film E over the same at a constant speed.

The up and down movement of the dog,

working in the loop of .the film below the gate, as shown in Fig. 1, acts in conjunction with the sprocket to move the film through the gate by successive steps. Thus when the dog descends with a rapid movement, it pulls down the film loop and thus draws the film rapidly through the gate, but when the dog pressure on the film and the latter is station- My t h gate whil t pictur is being projected on the screen. -Ho'wever during the upward movement of the dog, the sprocket takes up the excess loop of the film below the dog and maintains the film in light contact with the dog, so that 'when the dog begins its neXt'descent, it is in contact with the film and therefore merely pushes the film downwardly without striking against it. Thus noise'and shock are avoided and; consequently no injury is caused. to the film or the projectormechanism; e

Thisiinprov'ed result is due to the slower upward movement of thefdog, enabling. the sprocketto take up the slack'in the filrnfloop as the dog rises.

The. framing of the film is accomplished by adjusting the angle of framing lever 25,]

y 1 h lPd a of m e t i. 1' we The inner end, of shaft '29 is ,providedwith,

130 in extent a beveled gear 30 which meshes withj'aisimi lar gear 31 on a shaft '32 journaled iii the box 4. Theouter end of the .shaftf32 is pro,- vided with aism all gear 33 inmesh'withthe.

imparted to the, shutterH. V

The ratio and assemblage of the gears is lea large gear 7, whereby a rotary movement s such that'the shutter completesthreere zolutions to every round. trip or. complete cycle of the dog, passing in 'fro ntof thelens while c the dog is descending and, drawing the through the gate, and also passing ,befor'e tlie lens twice while the filmis stationary. Thus the same effect on. the .s'creenis pro duced as by the use of theconventional'threa blade shutter but by the use of but one blade. a larger percentage of light is an w amo ac he sc n, he ade bei n t than in extent, substantially .twortj hirds, 0

of the lightfrom the lens reaches the .screen.

Although, for the sake of c'learness, "I have minutely described the. construction shown in the drawin s, I donot Wish to I limit myself thereby, but claim broadly 5 1. In a moving picture machine, the combination with a moving picture film, of a gate through which said ,filni passeshairotary sprocket engaging said .film and .d-rawingFthe same through said gate, an. adjustable fra n- "130 i U a L ing lever, a swinging film dog pivotally mounted on said framlng lever and engaging said film between the gate and the sprocket,

and means for imparting a rocking motion to said dog whereby it intermittently pulls said film through said gate.

2. In a moving picture 'machine, the combination with a moving picture film, of a gate through which said film passes, a rotary sprocket engaging said film and drawing the same through said gate, an adjustable framing lever, a swinging film dog pivotally mounted on said framing lever and engaging said film between the gate and the sprocket to pull said film intermittently through said gate, and a rocking member acf tuating said dog and moving more rapidly in one direction than in the other whereby the looping movement of said dog is quicker than its. retracting movement and said sprocket is enabled to take up slack in the film, for the purposes described.

3. In a moving picture machine, the combination with a moving picture film of a gate through which said film passes, a rotary sprocket engaging said film, a rotating shaft, a second shaft receiving rotation at variable speed from said first shaft, a third shaft rocked by said second shaft, and a 30 looping dog engagingthe film betweensaid gate and said sprocket rocked by said third shaft.

4. In a moving picture machine, the combination with a moving picture film, of a gate through which said film passes, a

sprocket engaging said film and drawing it through said gate, a constant speed shaft, a second shaft, a variable speed crank connection between said shafts, a third shaft, a rocking crank connection between said second and third shafts, and a looping dog actuated by said third shaft and engaging said film, for the purpose described.

5. In a moving picture machine, the combination with a moving picture film, of a gate through which said film passes, a sprocket engaging said film and drawing it throu h said gate, a constant speed shaft, 9. secon shaft, a variable speed crank connection between said shafts, a third shaft, a rocking crank connection between said second and third shafts, a rocking looping dog actuated by said third shaft and engaging said film, and means whereby the loopin movement of said dog is at greater speed than its retracting movement, for the purpose described.

Signed at Los Angeles, California, this 31st day of August, 1915.

RALPH W. MARTIN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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