US330775A - Walter damby and alfred leduc - Google Patents

Description

(No Model.) W. DAMRY & A. LEDUO.

INSTANTANEOUS SHUTTER FOR PHOTOGRAPHY.

No. 330,775. Patented Nov. 1'7, 1885.

UNITED STATES PATENT OFFICE.

WALTER DAMRY AND ALFRED LEDUO, OF LILLE, FRANCE.

INSTANTANEOUS SHUTTER FOR PHOTOGRAPHY.

SPECIFICATION forming part of Letters Patent No. 330,775, dated November 17, 1885. Application filed April 22, 1885. Serial No. 163,046. (No model.) Patented in France November 8, 1884, No, 165,194.

T 0 all whom it may concern:

Be it known that we, WALTER DAMRY and ALFRED LEDUo, citizens of the Republic of France, residing at Lille, France, have invented new and useful Improvements in Instantaneous Shutters, of which the following is a specification.

This shutter serves for apparatus for instantaneous photography,'and has for its object to uncover the aperture of the lens during a very short time.

In the accompanying drawings, Figure 1 is a front elevation of the shutter. Fig. 2 is a side elevation. Fig. 3 is an elevation of the opposite side from that shown in Fig. 2; Fig. 4, a section on line A B, of Fig. 1; Fig. 5, a diagram showing the shutter at the moment when the lens-aperture begins to open. Fig. 6 shows the aperture uncovered. Fig. 7 shows the shutter at themoment when the aperture begins to be covered again. Fig. 8 shows the double curtain in perspective.

The chief part of the shutter is a curtain of textile fabric or the like, Figs. land 8, pierced with two holes equal with one another, and with the aperture of the lens for which the shutter is intended. The two extremities of this curtain are fixed below on two rollers, b and c, which are free to turn, and above the curtain passes over a roller, a, also capable of rotation. At the right-hand side, at the end of the roller 0, there is a spring-barrel, d, inclosing a coiled spring, which is capable of imparting to the curtain a movement of more or less rapidity. To give the necessary tension to the spring, the barrel d is turned by hand. A small graduated disk, m, automatically indicates the number of turns given to the barrel. This is effected by a small pin, d, fixed upon the latter, which at each turn pushes the wheel at one tooth farther, Fig. 2. The rim of the barrel is toothed, and the spring-pawl n serves as a stop. At the left end of the roller 12 is fixed a small circular plate, 70, fitted outside with several teeth held back by a spring, f, with a hooked end. Between the spring f and the casing is inserted an india-rubberball, 9, held in place by a claw, g. It communicates by a tube with a second ball, which the operator holds in his hand. When the operator compresses the ball in his hand,the other ball, is expanded and raises the locked spring f, thereby releasing the circular plate k. At the end of the roller 1) there is a head, h, by which it can be turned so as to raise the curtain for focusing and for setting the apparatus ready.

To use the apparatus, the head it is turned in the direction of the arrow, Fig. 2. The curtain is thus wound up on the roller 1), and unwound from the other lower roller, 0, the spring in the barrel (1 being at the same time wound up. This movement is stopped as soon as the two openings in the curtains are opposite one another, and the camera is then focused. hen the focusing is done, the head It is further turned until the aperture of the lens is entirely covered, and the apparatus is then ready to be used. The operator then grasps the india-rubber ball at the end of the tube, as previously explained, and when he compresses it the hooked spring f becomes disengaged, the, circular plate is released, and the spring-barrel causes a rapid rotation of the bottom rollers in a direction opposite to that herein above referred to, and this causes the curtain to be wound up on the roller 0 and unrolled from the roller 1). During this movement the two openings in the double curtain rapidly cross one another, and allow the light to pass during a very short time. Figs. 5, 6, and 7 are diagrams showing this movement. Fig. 5 shows the shape of the aperture for the passage formed when the two holes begin to cross one another. Fig. 6 shows the position when the light passes fully through the apparatusthat is to say, when the two openings in the curtain are directly opposite one another. Fig. 7 shows the shape of the aperture through which the light passes when the two holes are near the end of their passage over one another. By this arrangement the exposure begins at the center of the lens. The aperture is gradually increased to its maximum, and decreases until it is completely closed, this being likewise at the center of the lens.

Although the exposure is always very short by reason of the rapid action of the spring in the barrel (1, the exposure can be increased by causing a screw, 7), to press a spring, 1, against the circular plate, 70, at the end of the spring-barrel roller. This then serves as a break and checks the speed of the roller. Thus an exposure of half a second may be a tained. To obtain a high speed for the curtain t, when it is released, the spring-barrel (Z is turned by hand and the spring wound up. An exposure of one three-hundred-and-fiftieth of a second is thus obtainable.

1. The combination of the rollers a, b, and c with the curtain a, said curtain being passed from roller Z), over roller a, and down to roller 0, forming a double fold, each fold having a circular opening, with mechanism for winding the curtain on or off the rollers b c, whereby the openings pass each other in front of the lens, for the purpose set forth.

2. The combination, with the rollers and curtain, of the barrel d, the spring, the pin d, and the graduated disk an, for the purpose set forth.

3. An instantaneous shutter for use in photography, consisting of a box or casing containing a double curtain, i, mounted on three rollers, a b c, the roller b being provided with a handle, h, by which to operate the curtain, and the roller 0, having a springbarrel, d, and pawl 12, as set forth.

In testimony whereof we have hereto set our hands in the presence of two subscribing wito nesses.

WALTER DAMRY. ALFRED LEDUO. Witnesses:

R0131. M. HooPER, ACHILLE MARILLIER.

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