US993215A - Iris-diaphragm. - Google Patents

Description

A. WOLLENSAK.

IRIS DIAPHRAGM.

APPLIOATION FILED 11:11.27, 1911.

Patented May 23, 1911.

[lrmvmmkwm I, M (94 M k bmu/ wAsmns-rou. n. c,

a'rn

ANDREW WOLLENSAK, OF ROCHESTER,

FFIGE.

NEW YORK, ASSIGNOR 'IO WOLLENSAK OPTICAL COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

IRIS-DIAPHRAGM.

Specification of Letters Patent.

Patented May 23, 1911;

Application filed February 27, 1911. Serial No. 611,311.

To all whom it may concern:

Be it known that I, A DREW W OLLENSAK, a citizen of the United States, and resident of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Iris-Diaphragms, of which the following is a specification.

This invention relates to iris-diaphragms such as are employed in connection with photographic cameras.

The object of the invention is to provide a simple and effective device, to be used in connection with an iris-diaphragm of any ordinary form, for the purpose of frictionally retaining the blade-operating ring of the diaphragm in any position to which it may be adjusted, so as to prevent the adjustment of the diaphragm from accidental change through jarring of the camera or other cause.

To this end the invention consists in the device hereinafter described, as it is defined in the succeeding claims.

In the accompanying drawings: Figure 1 is a rear-elevation, with parts broken away, of an iris-diaphragm embodying the present invention; Fig. 2 is a section on the line 22 in Fig. 1; and Fig. 3 is a sectional detail view of the retainer.

The invention is illustrated as embodied in an iris-diaphragm constructed substantially 'like that described in United States Letters Patent No. 985,311 granted to me February 28, 1911, but it is equally applicable to any iris-diaphragm of ordinary form, that is, to any diaphragm comprising a series of blades and a rotatable ring by justed.

In the drawings the diaphragm is shown as mounted in a shutter-casing having a cylindrical body-portion 4 and a rearwardlyprojecting cylindrical portion 12 which is adapted to be screwed into the front of the camera in the ordinary manner. The blades 5 of the diaphragm engage, at their ends, two flat rings 6 and 7, the ring 6 being fixed to the casing by screws 8. The ring 7 is rotatable to adjust the blades in the usual manner, and is provided with an arm or flnger-piece 9 projecting outside the casing for this purpose.

The novel feature of the diaphragm in which the present invention resides is a frictional retainer for the blade-ring 7 This retainer is shown in place in Fig. 2 and detached in Fig. 3. It is in the form of a sub stantially flat plate 10 of thin resilient sheet-metal. In the drawings the thickness of this metal is exaggerated, for convenience in illustration, but in practice it may be made of very thin resilient brass or other metal.

At its outer edge the detent-plate 10 is provided with an annular flange 11. which may be formed integral with the plate by a suitable stamping operation. This flange is of such diameter that when the retainer is forced into the cylindrical portion 12 of the casing the' flange and the plate are held firmly in place by friction. This method of securing the retainer is not only simple and convenient, but it also permits adjustment of the retainer toward and from the bladering 7. The retainer is so adjusted that it bears against the rear surface of the bladering with resilient pressure, thus creating friction between the retainer and the bladering 7, and also between the two rings 7 and 6. In this manner the ring 7 is held with sufficient firmness to prevent its accidental displacement when in use.

The retainer-plate 10 is provided with a central opening in line with the opening through the diaphragm, and to stiffen the plate at its inner edge it is provided with an annular bead 13 and a forwardly-projecting flange 14. The bead and the flange may be formed by a suitable stamping operation, and they serve not only to stiffen the plate at its inner edge, but also to give a neat fin- ,ish to the parts, as the flange overhangs the which the blades are simultaneously adedge of the blade-ring 7 and serves to conceal the raw edges both of this blade-ring and of the retainer itself.

I claim 1. An iris-diaphragm having, in combination, a cylindrical casing, a blade-ring rotatable in the casing, and a frictional retainer for the blade-ring comprising a substantially flat circular resilient plate with a central opening and a peripheral flange, the plate being held in yielding frictional engagement with the blade-ring by the frictional engagement of its peripheral flange with the inner surface of the casing.

2. An iris-diaphragm having, in combination, a cylindrical casing, a blade-ring rotatable in the. casing, and a frictional retainer for the blade-ring comprising a sub- With the inner surface of the casing and the stantlally flat circular reslhent plate wlth a flange at said opening overlapping the inperlpheral flange and with 21 central openner edge of the blader1ng.

ing bounded by a flange and a head, the ANDREW WOLLENSAK. plate being held in yielding frictional en -Witnesses:

gagement With the blade-ring by the fric- D. GURNEE tional engagement of its peripheral flange L. THON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, 1). G.

Images