US1823293A - Photographic shutter retarding mechanism - Google Patents

Description

' Sept. 15, 1931. w, RlDDELL 1,823,293

PHOTOGRAPHIC SHUTTER RETARDING MECHANISM Filed Dec. 20. 1929 Patented Sept. 15, 1931 UNITED STATES PATENT OFFICE WILLIAM A. RIDDELL, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COM- PANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK PHOTOGRAPHIC SHUTTER RETARDING MECHANISM Application filed December 20, 1929. Serial No. 415,472.

This invention relates to photography and more particularly to photographic shutters.

One object of my invention is to provide a simple and durable connection between a power drive and a retarding device by which exposures of various durations may be obtained. Another object ofvmy invention is to provide a lost-motion connection between a driving device and a retarding device which can be readily set. Other objects of my invention will appear from the following specification, the novel features being particularly pointed out in the claims at the end thereof.

This invention relates to shutters having a retarding device which has a variable relation with a setting device so that the shutter blades may be made to operate at different speeds as, for instance, is shown in another form in Patent 1,341,823, Riddell et al, June 1, 1920.

Coming now to the drawings wherein like reference characters denote like parts throughout Fig. 1 is a front plan view of a shutter with a portion broken away showing a speed retarding connection constructed in accordance with and embodying a preferred form of my invention;

Fig. 2 is a fragmentary detail view of the lost-motion connection between the retarding and the driving device in one position;

Figs. 3 and'5 are views of similar parts in different positions;

Fig. 4 is a view of the parts shown in the preceding three figures with the addition of a tripping lever;

ig. 6 is an enlarged plan view of a retarding member constructed in accordance with another embodiment of my invention; and

Fig. 7 is a diagrammatic view to illustrate the relation of the setting lever to the movement of the retarding mechanism.

In certain types of shutters a spring is provided for furnishing the power and this spring is set in advance of each shutter operation. These shutters are ordinarily referred to as setting shutters.

In Fig. 1. I have illustrated a setting shutter in which the shutter comprises a cupshape portion 1, having a flange 2 extending around its periphery and a central upstanding flange 3, there being a shutter cover plate 4 extending between the flanges 2 and 3. The upstanding flange 3 is ordinarily thliieaded on its inner side 5 to receive a lens ce The shutter is provided with a spring 6 which surrounds a post 7 and which engages a lug 8 in such a manner that the post 7 is normally thrust in a counter-clockwise direction. The post 7 carries a plate 9 provided with a lug 10 adapted to engage and rest upon a post 11, the plate 9 also being provided with a stud 12 which is eccentric to the post 7.

Post 7 also carries a setting lever 13, the normal position of rest of this setting lever being indicated by I in Fig. 1. In order to tension the spring, the lever 13 is moved from the position shown in Fig. 1 to the position shown in Fig. 4 in which the lever lies in position IV. In this position the disk 9, which has also a lug 14 is engaged by the end 15 of a trip lever 16 pivoted at 17 and terminating in a handle 18 through which the exposure is made. The lever 16 is normally thrust about its pivot 17 in a clockwise direction by means of a spring 19 By pressing downwardly upon the lever 18 the end 15 of lever 16 moves away from lug 1 1 and permits the spring 6 to rapidly turn post 7 until lug 10 strikes the post 11.

Only a small part of the movement of the setting lever 13 between positions I and IV is utilized in making the exposure. As the lever 13 is moved to position II in Fig. 2 the pin 12 slides down an arcuate edge 21 of a yoke member 22 which is pivoted at 23 to the shutter cover, the opposite side of the yoke member having a curved face 24. The curved edges 21 and 24 are connected by a short wall 25, the function of which will be hereinafter more fully described. As the setting movement progresses from the position II to the position III shown in Fig. 3, the pin 12 rides past the curved face. 21 into contact with the curved face 2 1. It

should be noted that thesefaces are curved differently and the pin 12, in rotating about post 7 has sliding contact with the curved face 24 and moves the yoke member 22 about its pivot 23 in the direction shown by the arrow. Continuing the downward move ment of lever 13, it finally comes to rest latched behind the lever 16 in position IV shown in Fig. 4. In this position the pin 12 is at the upper end of the curved face-'24.

When the trigger 18 is released the lever 13 moves idly about its shaft 7 through. roughly about as indicated inFig. 7, at which time the pin 12 strikes the short wall 25 and moves the yoke 22 rapidly about its pivot 23 until the-pin strikes the curved surface 21 whichis concentric with thepath' of movement of the pin.

In Fig; 5;.in the position shown at V the pin is engaging the short wall 25 and is driving't-he yoke member 22. AS the parts move a little further in a counter-clockwise direction, the pin slides idly along the curved wall 21: and the yoke 22 is not moved until thegnext setting operation occurs-.

From the diagrammatic showlng of Fig. 7 thelever 13' can be seen tomove'the greater part of its total movement idly, that is'to say, the'first and last part of the movement,

- substantially 55 in each case, does notafi'ect Approximately 16 in the middle of the stroke is the part actually used the exposure;

for retarding the exposure. v

In my copending application, SerialNumber 340,239, filed February 1-5, 1929 for Photographic shutter blade actuating mech-,

anism, I have fully shown and: described-v the mechanism bywhich the shutter blades are moved from the master member which,

in this case, is the power driven post 7 Reference may be had to this application for the driving connection between the blades andmaster member; F or the: present application it is only necessary for an understanding of the invention to know that, as-

indicated in Fig. 7, a small portion of the operating stroke, asindicated at O is used for opening" the shutter blades, approxi mately16 is used for retarding the shutter blade-s (where any retarding action occurs) and a small portion of the movement beyond the retarding action indicated at C is used to'close the shutter blades;

"The only reason for giving the angular movement of the setting lever 13 is that it greatly facilitates describing the invention. In the particular shutter measured, the angular movement of the setting lever was as here described but obviously more or less co ld be readily aCC'OmPlISlIGCl changing the design somewhat without altering the invention. The portions indicatedat O and C are entirely diagrammatic and do not illustrate the angular movement of the post 7 necessary to accomplish these movements since the opening and closing movement of the blades is extremely rapid in the order of .002 to .004 of a second. The

time it takes the post 7 to travel the retardbeing provided with a rack 40 adapted to mesh with a pinion 41 adapted to turn with a setting dial 42. By turning this setting dial the pin 33 may be made tomove through the co-operating slots 34 and 32, these in effect being quite similar to the slotted levers shown in my Patent 1,341,823, above referred to.

The gear segment 30meshes with a gear 43*which may be one gear of a gear train similar to the showing of my prior patent;

It will be noticed that the slot 34 in the" yoke 22 is of irregular width throughout its length, this width being utilized to make the distance between the graduations'47 on the dialplate 42 equal or substantially equal,

as will be more fully described in my copend ing application, Serial Number 415,473, filed December 20, 1929.

Theoperation of my invention: is as follows. Assuming a 25th of a second exposure isto be made the dial 42 is set with 25 beneath the pointer 48. The setting lever 13' is-moved from position Ito position IV in which lever 16 engages the lug 14. By de-- pressing the trigger 1-8', post 7 turns rapidly causing pin 12 to'ride idly down over the curved face 24 until it strikes-the short wall 25, atwhich time it rapidly moves the yoke 22 upon its pivot 23 until the pin 12 may ride idly up the face 21. Thetime during'w'hich the pin12 will engage the short wall 25, is substantially a 25th of a second. dial should have been set with the numeral 2 beneath the pointer 48' this time would be changed to a half a second since the pin If the 33' would have been moved to a different position in the two slots 34 and 32"and thus the leverage of the retarding gear train would have been altered.

In Fig. 6 I have illustrated a second. em-

bodiment of my invention in which the yoke- 122' is-provided with a pair of curved faces 123 which are of substantially the same ra-: dius but which have offset centers of curva-- ture'. The short wall here consists of anotch 124. 'When the; master member is moved so that pin 12' slides idly 'down: a

face 123 it will engage the notch 124 and turn the yoke 122 u on its pivot.

The advantage 0 having the yoke shaped as shown in the preceding figures is that the setting movement requires less effort since the yoke 22 is moved comparatively slowly by the pin 25 striking the curved face 24. The yoke 22 will be moved rapidly when the pin 12 strikes the short wall 25, however, so that the operative movement in which the pin 24 moves the yoke 22 is the same as the operative movement where the pin 120 moves the yoke 122 in Fi 6. In the setting movement in Fig. 6, however, the pin 120 engages the notch 124 and moves the yoke 122 more rapidly towards its set position and as this setting movement is accomplished against the retarding gears it is more difiicult to set a shutter with the parts constructed as shown in Fig. 6 than it is to set the shutter with the parts shown as constructed in the other views. If, however, only short retarded exposures are to be made this is not a very material feature.

Having thus described my invention, what I claim as new and desire to be secured by Letters Patent of the United States is:

1. In a photographic shutter, the combination with rotatably mounted master member, of a retarding device, and a lost-motion connection between the retarding device and master member including a yoke and a pin adapted to engage the yoke and being adapted to drive the yoke in two directions, said pin being carried by the master member.

2. In a photographic shutter, the combination with rotatably mounted master member, of a retarding device, and a lost-motion connection between the retarding device and master member including a pivoted yoke having a plurality of pin engaging surfaces. a pin carried by the master member adapted to engage said yoke surfaces.

3. In a photographic shutter, the combination with rotatably mounted master mem ber, of a retarding device, and a lost-motion connection between the retarding device and master member including a pivoted yoke including arcuate pin engaging surfaces, and a pin carried by the master member for enga ing these surfaces.

4. n a photographic shutter, the combination with rotatably mounted master member, of a retarding device, and a lost-motion connection between the retarding device and master member including a pivoted yoke including arcuate pin engaging surfaces connected to each ot er by a short wall, and a pin carried by the master member and adapted to engage the arcuate surfaces and to drive the yoke through engagement with the short wall.

5. In a photographic shutter, the combination with rotatably mounted master member, of a retarding device, and a lost-motion connection between the retarding device and master member including a pivoted oke including arcuate pin engaging sur aces on offset centers, and a pin carried by the master member for engaging the arcuate surfaces.

6. In a photographic shutter, the combination with a master member, of a rotatably mounted master member, a retarding device including a pivoted yoke having arms embracing the master member and a pin carried by the master member adapted to engage the arms.

7. In a photographic shutter, the combination with a master member, of a rotatably mounted master member, a retarding device including a pivoted yoke having arms embracing the master member and a pin carried by the master member, the relation of the pin and arms being such that the pivoted yoke may be rocked upon its pivot by the master member through the successive engagement of the pin with the arms of the yoke.

Signed at Rochester, New York, this 16th day of December, 1929.

WILLIAM A. RIDDELL.

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