US339910A - Chakles p - Google Patents

Description

(No Model.)

0. F. MARVIN PHOTOGRAPHIG SHUTTER. No. 339,910. Patented Apr. 13, 1886.

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UNITED STATES PATENT OFFICE.

CHARLES F. MARVIN, OF XVASHINGTON, DISTRICT OF COLUMBIA.

PHOTOGRAPHIC SHUTTER.

SPECIFICATION forming part of Letters Patent No. 339,910. dated April 13, 1886.

Application filed February 23, 1886.

To whom, it may concern:

Be it known that 1', CHARLES F. DIARVIN, of the city of W'ashington, District of Columbia, have invented anew and useful Improvement in Photographic Shutters, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, making part of this specification. I

My invention relates to improvements in photographic shutters or devices for making exposures of photographic plates, the objects of my improvements being, first, to cause an aperture to be consecutively and quickly opened and closed by a piece moving in such a way as to admit as large a quantity of light through the aperture or opening in the given time as possible; second, to provide means by which the moving piece may be automatically stopped when the aperture is fully opened and held in this position for any length of time desired, and then closed. The mechanism by which these objects are accomplished is illustrated in the accompanying drawings, forming part of this specification, in which Figure l is a front view of the shutter with the lens-tube removed and part of the front plate broken away to show the vibrating plate inside. Fig. 2 is an edge view of the same, showing the lens-tube in position.

Similar letters refer to similar parts on both drawings.

The thin ease A,having a circular aperture or opening, a a a, cut through its two opposite faces, serves as a frame-work for the mechanisms, and isitself inserted into the lenstube T, Fig. 2, at a point between the two lenses, so that the aperture a a a is concentric with the lens-tube.

The plate B, Fig. 1, pivoted at B, and of a form covering the aperture a a a, is contained within the thin case A, and by means of the lever L, pivoted at L, actuated by the spring S, connected to the plate B by the connecting link Z, and the pin 13'' passing through the slotted hole A into plate 13, the said plate B is made to vibrate from the position, as at B, to that at B and back again to the first position, when the lever L on being released by the hook h, as hereinafter explained, moves with continuous motion to the position at L, in which action the aperture a 0. a is opened Serial No. 192,905. (No model.)

and quickly closed again. The leverL is furnished with various notches, a n, &c., into which the spring S maybe caught to give different velocities to the lever L. It is seen that the plate L is made to vibrate through a larger are than is necessary to simply open the aperture (4 a a. This overdraw in the motion of the plate B serves to make the time oceu pied in the operation of actually opening and closing the aperture only a small percentage of the whole time of exposure, inasmuch as the aperture is fully open all the time the plate B is passing over this overdraw. The aperture thus remaining fully open for a large proportion of the whole time of expos ure, a greater quantity of light is admitted through the aperture in the given time than would have been if the aperture had begun to close very shortly afterit was fully opened.

H and O are two levers pivoted at D, and provided with hooks 71, I1, and c, and pins 71 and c.

S" is a spring fastened to the case A at S, and pressing the lower end of lever C against a fixed stop, P, causing the hook c of the upper end of said lever to be held aside so as not to engage the pin P of the lever L.

S is another spring, or portion of the same spring just described, which presses the upper end of lever H against the stop 0 on lever O, in which position the hooks h and h of lever H are thrown forward, so that either may engage the pin 1? of lever L. The said hooks, however, have their upper edges inclined backward, so that when the lever L is depressed the pin P, rubbing against these inclined edges, causes the lever H to move laterally to allow the pin P to pass the point of the hooks and be caught by them.

I? is a stop or pin fastened to the case A, and against which the levers H and 0 may strike when drawn backward against the pressure of the springs S and h and h are hooks formed on lever H, to engage the pin 1? of lever L. c is a similar hook formed on lever C, to engage the said pins, all as hereinafter described.

0 and h are pins or holes or other means belonging, respectively, to the levers G and H, and by which pressure may be applied to said levers, as hereinafter described.

Having thus described the various parts of IOC of the finger or the pull of a string, or by a" pneumatic device-is applied to the portion h of lever H, said portion being properly formed to receive the impulse. The said pressure or impulse forces the lever H back against the stop or pin 1?, causing the hook h of lever H to be disengaged from the pin P of lever L, which lever, actuated by the spring S, moves forward, causing the plate B to open and quickly close the aperture a a a, as before described. Thus I make a very short exposure. To restore the mechanism to the previous condition and thus set the shutter for further use, I simply depress the lever L until the pin P is caught by the hook it of lever H, the said hook h and its fellow h having their edges in elined, as and for the purpose stated above. In case I do not wish to close the aperture a a a, but desire to have it remain open, for focusing or otherwise, I simply catch the lever L by its pin P on the hook h, in which position of the parts the aperture is open.

Second. A longer or so-called "time exposure is made thus: For example, Idesire to open the aperture, and when open to automatically arrest the motion of all the parts, and then after the aperture has remained open the desired length of time to release the parts and let them move to their final position, thus closing the aperture. This is accomplished in the following way: In any of the ways mentioned above pressure is applied to the portion 0 of lever O,formed to receive said pressure according to the method by which it its applied, the said pressure causing the upper portion of lever C with its hook c to move toward the stop or pin P and by reason of the pin or stop 0 of lever O pressing against the edge of lever H, this latter is alsocarried toward the pin or stop P, the levers H and 0 moving together just as if they were one piece of material. Toward the end of this movement the hook h is wholly withdrawn from the pin P of lever L,which lever, actuated by the spring S, is thrown forward, but is imme both levers back to their first position.

mediately caught by the hook c of lever O. In this position of lever L the aperture a a a is wide open. The impulsive pressure applied to the lever O is sooner or later removed. Then the springsSand S acttothrow This disengages the hook c from the pin P, which "is no sooner released from hook 0 than it is caught by the hook h, in which position, the aperture (1 a a being still open, it remains untilit is desired to close the aperature,whieh is done by a second application of pressure, which in this case may be to either of the levers, as at c or h I have previously explained how the shutter is set, ready for action.

Having thus described my invention,whatI claim as new, and desire to secure by Letters Patent, is a 1. In a photographic shutter, the combination of the vibrating plate B, the bell-crank lever-arm B and the lever L, provided with the notched extension L, actuated by the spring S and connected to the plate B by its pin '13, and the link Z, all substantially as set forth.

2. In a photographic shutter, the combination ofthe lever L, and the hooked lever H,furnished with means a for applying pressure to it and adapted to be acted upon by the spring S, to cause the hooks h and h to engage the pin P of lever L, all substantially as described, and for the purpose specified.

8. In a photographic shutter, the combina tion of the lever L with the levers H and O, the latter furnished with a spring, S to keep the hook 0 out of the path of the pin P on the lever L, and provided with a pin or stop, 0, which presses against lever H, causing said lever to move when lever O is moved by pressure applied to the portion 0, adapted to receive said pressure, all substantially as described, and for the purpose specified.

4. The combination, in a photographic shuttor, of the thin case A, provided with a circular opening, a a a, and carrying a vibrating plate,

B, with the hooked levers G and H, the latter being adapted to act independently or in conjunction with the lever O, in manner and form specified.

In testimony whereof I have hereunto set my hand this 23d day of February, A. D. 1886.

O. F. MARVIN. Witnesses:

M. A. BALLINGER, N. B. CLARKE.

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