US1785142A - Objective shutter - Google Patents

Description

Dec. 16, 1930. R. NERRLICH 4 OBJECTIVE SHUTTER Filed Nov. 21. 1929 2 Sheets-Sheet l (d I /zh Dec. 16, 1930. R. NERRLICH OBJECTIVE SHUTTER 2 Sheets-Sheet 2 Filed Nov. 21, 1929 Patented Dec. 16; 1930 UNITED STATES PATENT OFFICE RICHARD NERRLICH, OF BERLIN, GERMANY Application filed November 21, 1929, Serial No. 408,852, and in Germany November 23, 1928;

lever-like arms connected with one'another.

in known manner by a toggle-joint lever. This known arrangement and combination of -parts has been improved, according to this invention, as follows: I

The middle pivot of the toggle lever which projects over the arms of this lever at their junction and is guided with this proj'ectmg end in a slot of a sleeve is utilized as a means for damping the shutter halves at the very last portion of their closing path, the object of this damping being the obviation of defective exposures. The object'in view is attained best by combining with said pivot a piston guided in said sleeve which forms at its lower end a cylinder in which the quickly descending piston compresses air at the end' of its path and is thereby quickly, as well as softly, intercepted. 1 The invention is illustrated diagrammatically and by way of example on the accompanying drawings, on which Figure 1 is a .front view of a shutter designed according to this invention, only one frame part (of which portions are visible in the middle parts of Figs. 2 and 3) being omitted in order to show more distinctly the parts located therebehind; Figure 2 is a similar View showing .some of the movable parts in another position; Figure '3 shows certain of these parts in still another position, and Figure 4 is a ver tical section through the middle of the de-.

" vice, all. as fully described hereinafter.

a and a are two semicircular shutting members proper. They are shown closed in Figs. 1 and 3, and open in Fig. 2 and they are secured to the ends of oscillable arms I; and b movably suspended at 0 and 0' at the rearv wall at of the shutter frame. The members 5 a and a, as well as b and b, are arranged symmetrically with respect to the axis of the objective and are moved towards, as well as away from, one another by means of the arms 6 e of a toggle-joint lever which are connected with the arms 6 b by means of pivots f f, and with one another by means of a pivot g. This pivot is located in a piston k which is guided in a sleeve i having at its front face a vertical slot 71 into which extends the forwardly projecting end of the pivot g.

The piston h is laterally slotted, and the inher ends of the toggle-joint lever arms extend through these slots into the interior of the piston where they are connected with this latter and with one another by means of the pivot g.

T e tog le-joint lever arms 6 e are subjected to the pull of oblique helical tensile springs j connected at their upper ends with said arms and at their lower ends with the rear plate of the frame. These springs tend continually to hold the arms 6 e in the position shown 'in Fig. 1. When these arms are in this position, the position of the shutters arms I) b is such that the shutter members proper a a are in their shutting position, as in Fig. 1.

In front of the shutter arms 6 b is located a lever 1' which is fulcrumed at p to the rear frame plate 01 or, more precisely, to a projection of said plate so that the lever 1* lies somewhat remote from the said plate, viz. just in front of the slotted sleeve 71 which it crosses below the projecting end of the toggle-joint pivot 9 (Figs. 1 and 2).

From the upper end of the sleeve 2' is suspended on a pivot is a bell-crank lever consisting of a shorter arm m and alonger arm m. The shorter arm is designed as a pawl m and the longer arm is connected with a helical tensile spring 0 tending to hold the lever m m in such a position that the pawl m extends over the slot 11, viz. over the upper end thereof, as in Fig. 2. Normally, however, the springjo is prevented from holding said bell-crank lever in said. position, in that the arm m of this lever is subjected to the action, i. e. pressure, of a pin 1-. extending forth forwardly from an. u wardly directed extension forming 'a part 0 the lever 1', near 1 the fulcrum p thereof. In the normal position, or position of rest, of the parts concerned their position is that shown in Fig. 1 in which the pawl m does not cover the slot 11' of the piston guiding member 2'. In this position of the parts the shutter is closed.

When the shutter is to be actuated (for momentary exposure or exposures), the lever r is turned in the direction indicated by the arrow shown at the lefthand side of Fig. 1, whereby the toggle-joint junction pin or pivot 9 will be lifted, in consequence whereof the toggle-joint arms 6 6' will be oved asunder, as will also theshutter arms I) b and the shutter members proper a a, the position being then that shown in Fig. 2. But this is merely a medium position. While the lever 1' has been turned, as just described. its pin 1'' has at a certain point of its path left the arm m of the bell-crank lever m m and prior thereto the spring 0 has turned this lever so that its pawl m has finall arrived over, or in front of, the slot i. ile the lever r is further turned upwardly, the position of the toggle-joint lever arms is reversed (Fig. 3) and finally the pin or pivot.

9 contacts with the pawl m and passes along and over it, during which time the pawl is first pressed back and then re-assumes automatically (under the pull of the spring 0) its former position, that is to say, that position in which its active portion lies over the slot i. In this moment the pivot g is locked by the active pawl portion (Fig. 3), and

when now the lever 'ris released or dropped it falls back into a certain medium position, viz. that in which its in 7" a ain contacts with the arm m of the ell-cran li lever m m, as in Fig. 3. J

While the lever r had been moved from the position Fig. 1 into the position Fig. 3, the shutting members a a has been opened and closed, and simultaneousl therewith the springs j 9' have been expan ed (Fig. 3).

The device is now in its operative position.

for momentary exposure, and the operation for making such an exposure, i. e. the next actuation of the device, consists merely in further depressing the lever 1' so that the pin 1" presses upon the arm m of the bell-crank lever and turns thereby this lever, in conse-' quence whereof the pawl m will be withdrawn from the pin or pivot 9. Now the expanded springs 7' can become operative, and they now stretch instantaneously the togglejoint lever (position Fig. 2, in which the shutter arms I) b are moved away from one another, as are consequently, also the shutter members proper a a) and turn them in the next moment to an angle (position Fig. 1, in which the position of the parts a a and b b is the same as in Fig. 3). the shutter has been opened a very short time, a fraction of a second, and a momentary exposure has been made in that fraction.

In other words:

- It need hardly be said that together with the toggle joint 'unction pin or pivot 9 also the iston 6 has een torn downwardly very quic ly by the springs j, and on the very last portion ofits path it has entered into. the damping cylinder 7? whereby the damping intended is attained. The strength of this damping action can, if desired, be regulated by providing the cylinder 2' with an airescap'e regulating screw, or any equivalent provision may be made. In every case the shutter members proper a a are prevented, by the damping, from even the slightest rearward'movement after they have arrived in their end position in which the shutter is completely closed, and this being so, defective exposures are completely prevented.

I claim:

1. An objective shutter of the character described, comprising, in combination, a pair of oscillable arms adapted to be moved towards, and away from, one another and forming at their free ends the shutting members proper for the objective; a toggle-joint lever located between said arms and being connected with them; springs engaging the toggle-joint lever arms and tending to maintain said shutter members proper in closed position; a slotted longitudinal member also located between the oscillable arms and behind said toggle-joint lever, the middle junction pivot of this lever engaging said slot; and damping means so arranged as to be adapted to intercept the said shutter members proper just before the very end of their closing path.

2. An objective shutter of the character described, comprising, in combination, a air of oscillable arms adapted to be move towards, and away from, one another and forming at their free ends the shutting members proper for the objective; a toggle-j oint lever located between said arms and bein connected with them; springs engagingt e togglejoint lever arms and tending to maintain said shutter members proper in closed position' a slotted longitudinal member also located between the oscillable arms and behind said toggle-joint lever, the middle junction pivot of this lever engaging said slot; and means so arranged with respect to said pivot as to intercept it'just before the end of its downward path and to stop thereby elastically also the other movable members connected with it directly and indirectly, substantially as set forth.

3. An objective shutter of the character described, comprising, in combination, a pair of oscillable arms adapted to be moved towards, and away from, one another and forming at their free ends the shutting members proper for the objective; a toggle-joint lever located between said arms and being connected with them; springs engaging the toggle-joint lever lib arms and tending to maintain said shutter members proper in closed position, the lowermost portion of this member being designed as a cylinder, and the said member being also located between the oscillable arms and behind said toggle-joint lever, the

middle junction pivot of this lever engaging said slot; a piston located in the slotted longitudinal member and being connected with said pivot, this latter being adapted to damp elastically the movable' members connected directly and indirectly with it just prior to said shutting members proper arriving in their closed position.

4. An objective shutter of the character described. comprising, in combination, a pair of oscillable arms adapted to be moved towards, and away from, one another; semicircular shutting members proper attached to the free ends of said arms; a toggle-joint lever located between the said arms and being connected with them; springs engaging said toggle-joint lever and tending to keep said shutting member proper in closed position; a sleeve arranged between the osc'illable arms behind said toggle-joint lever and having a longitudinal slot receiving the middle junction pivot of the toggle-joint lever arms and guiding directly said pivot and the movable parts connected therewith; a piston-like member arranged within said sleeve and being connected with the said pivot and adapted to be moved upwardly and downwardly in the said sleeve in correspondence with the,

toggle-joint lever arms and the-parts connected with them; a cylinder constituting the lowermostend of the said sleeve and forming a damping space for said piston when this latter arrives at the very end of its path, substantially as set forth.

5. An bjective shutter of the character described, comprising, in combination, two

practically parallel one-armed levers terminatin at the objective; semi-circular objective s utting members attached to the ends ofsaid levers and forming together the shutter proper for the objective; a sleeve arranged between said levers practically parallel to them and having a slot at its front face and forming a cylinder at that end which is located near the objective; a piston arranged in said sleeve; toggle-j oint lever arms arranged in front of said slot and being connectedwith the middle junction-pin of the toggle-joint lever; and springs engaging the toggle-joint lever arms and tending to turn them so as to keep the shutter proper closed,

substantially as set forth.

In testimonymhereof I aflix my signature.

' RICHARD NERRLICH.

Images