US1317575A

US1317575A - Jens peter hansen

Info

Publication number: US1317575A
Authority: US
Publication date: 1919-09-30
Anticipated expiration: 1936-09-30

Description

J. P. HANSENA SHUTTER FOR PHOTOGRAPHIC CAMERAS. APPLICATION FILED DEC- 10. 1918.

1,317,575. Patented Sept. 30, 1919.

J ENS PETER HANSEN, OF COPENHAGEN, DENMARK.

SHUTTER r03 PHOTOGRAPHIC CAMERAS.

Specification of Letters Patent.

Patented Sept. 30, 1919.

Application filed December 10, 1918. Serial No. 266,171.

To all whom it may concern:

Be itknown that I, JENs PETER HANsnn, a subject of the King of Denmark, and mmdent of Copenhagen, 10 Jacobys Alle, Denmark, have invented certain new and useful Improvements in Shutters for Photographlc Cameras, of which the following is a Specification.

The present invention concerns an improvement in shutters for photographic cameras. The novel feature of the invention is the use of bent edges on the shutter door or doors, which edges cooperate with corresponding notches in the shutter board so that by the closing of the doors an a1r cushion is formed (as it is very difficult for the air to escape through the narrow space between the edges of the doors and the aforesaid notches) which air cushion highly contributes to render the closing quite noiseless, lighttightness being besides obtained in. a specially easy and safe way, which will be 7 described later.

The invention is shown on the drawing, where:

Figure 1 shows a double door-shutter, seen from the rear-part of the camera, the doors being open.

Fig. 2 is a section on the line IIII, Fig. 1.

On the drawing 1 is the shutter-board the back of which has a projecting part 2,which cooperates with the doors. These consist of a door-plate 3 with bent edges or flanges 4: and 5, which exactly inclose the projecting part 2. One of the joining edges of the doors may have a projecting felt strip 6 and the other a corresponding strip 7 in order to attain light-tightness where the doors meet. The doors are fitted on turning

rollers

8 and 9, which, in proper way are mounted in

strips

23 and 24 on the shutter board. In order to secure synchronical cooperation, the

two rollers are in known manner provided with a crossed cord 10 and in order to secure the closing of the doors, a coil spring 11 is secured to one of the rollers the other end of the coil spring being fastened to the shutter board.

By shutters with bent edges (especially if the edges as those on the drawings 12, are bent in the direction of the lens) absolute light-tightness around the pro ecting part 2 can be obtained, if the edges are given a certain height even if the doors are adjusted in such way, that they stop at a distance of 3-3 m. m. from the projecting part 2, the light being unable to escape in the direction of the plate or the film, as is the case, when the doors have no bent edges, but being forced in regressive direction against the shutter-board. (It is supposed, that the shutter is mounted behind the lens). And the possibility of stopping the doors by their closing some distance from the shutter board, (which can be done by suitable means), without the door striking the shutter board, and yet without endangering the light-tightness. is of the greatest importance for the attaining of a quite noiseless closingand without such no really good studio-shutter can be obtained.

It should further be mentioned, that the felt strips 6 and 7 may be applied in such way, that they are pressed against each other by the closing of the doors, which contributes to an even stopping The bent edges of the doors must besides fit tightly to the projecting part of the shutter frame and the bent edges of the one door must be over the edges of the other door, so that by the closing an air cushion is formed which excludes any shaking and sound. In

like manner, the edges of the device described will secure absolute light-tightness. Having now described my invention what I claim as new and desire to secure by Letters Patent, is

1. In a photographic camera, a shutter frame having a projecting portion, and a shutter formed of two plates hinged to the frame and provided with inwardly extending flanges engaging the edges of the projecting portion of the frame,'the edges of the said plates overlying one another when closed.

2. In a photographic camera, a shutter frame having a projecting portion and a shuttei' formed of two plates hinged to the In testimony whereof I affix my signature shuttef fragjne and provided with1 inwafrdlly in presence of two witnesses.

extenc ing .a nges en zwing the e ges 0 tie 1 T said projecting portion of the frame, the JENS PETER IIANSILL' edges of the plates overlying one another Witnesses:

when closed and provided With packing E. SLECKHAHN,

strips. CHAS. UNDER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.