Hood For A Focusing Screen Of A Camera

Abstract

A focusing or light-hood for a focusing screen of a photographic camera, the hood having three hinged plates and a hinged front covering plate, forming a square hood, in which the front covering plate can be folded over the focusing screen, the hood having a structure wherein the uppermost front covering plate is pressed to be turned backward for being folded, the turning movement of which is transmitted to the other three covering plates pivotally mounted on two sides and the back of the screen, the closure of the hood being caused by pressing the front covering plate; the hood which is thus collapsed can be errected with one touch of the front covering plate.

Description

SUMMARY OF THE INVENTION

The present invention relates to a hood for a focusing screen of a camera in which a hinged front covering plate, by its rearward movement causes hinged covering plates on two sides of the focusing screen to turn inwardly, screen in turn, and then the following which a back covering plate is brought down over the side covering plates already folded on the screw and finally the front covering plate is turned backward over the back covering plate to be folded so that all the covering plates are to be folded in a sequence which causes the front covering plate to be on the top.

The object of the invention is to provide a novel system of said hood for a focusing screen of a reflex camera in which the front covering plate includes a pair of stays on either side of the front plate, the stays forming cams at the lower portion thereof, respectively for the purpose of making the side plates move inward at a slightly different times with a short time lag inbetween.

BRIEF DESCRIPTION OF THE DRAWING

Above and other objects, features and advantages of the invention will become apparent from the following description of the embodiments shown in the drawings wherein:

FIG. 1 is an isometric view of a hood for covering a focusing screen of a camera, shown in part section.

FIG. 2 is a vertical side view of the main portion of the hood.

A front covering plate 1, a back covering plate 2 and side covering plates 3 and 4 are respectively supported on pins 10 provided on a square frame 5 and are pivotally rotatable thereon. The pins of the back covering plate 2 and side covering plates 3 and 4 are provided with springs 10' respectively, one end of each spring being fixed to the respective pin, while the other end is fixed, to each of the covering plates 2, 3 and 4 respectively, so as to bias them to keep open.

The edges of the side plates 3 and 4 engage in assembly the inside of the angularly bent edges 2a of the back plate 2 at opposite ends thereof, forming a hood together with the front covering plate 1, in the open position of all the plates 1-4.

A pair of stays 6 and 6 for controlling the angle inclination of of the front covering plate to be opened, are provided and these are supported pivotally on the shafts 5a and 5a fixed on both sides of the frame 5. Each of the stays 6 has a long slot 6a through which a pin 1a is fixed to the side plate so as to enable the front covering plate 1, to be guidingly moved.

On each side of the frame 5 is provided a lever 7 for closing and opening, which has a projection 7b bent in a lateral U-shape at the front end thereof, and is supported pivotally on a shaft 5b, while a spring 8 circling the shaft 5b is fixed to a projection 5d, so that the spring 8 forces the lever 7 outwardly, added by the roller 7a arranged rotatably at the middle portion thereof.

Each stay 6 has a semicircular upstanding portion 6b around a member 5a in the center thereof forming a cam 6c which engages with the roller 7a on the lever 7 positioned beneath the cam 6c.

For the purpose of operating the side covering plates 3 and 4 with a short time lag the positions of the cams 6c of the stays 6 should not be similar; a pin 6e is fixed to the stay 6 and a link 9 is connected with the pin 6e at the middle portion of the link 9 is formed a slot 9a through which a guide pin 5c fixed, to the frame 5 is provided. A pin 9b for moving the back plate 2 is fixed to the end portion of the link 9, the pin 9b being slightly spaced from the back plate 2.

When the cam 6c of the upstanding wall 6b pushes the roller 7a and the lever 7 rotates inwardly against the force of the spring 8, the left side plate 3 (in FIG. 1) is pressed inwardly by the projection 7b, so that the left side plate 3 is turned in.

The right side plate 4 (in FIG. 1) is similarly operated a little later than the the plate 3 owing to the different positions of the cams, (either of side plates can be operated, earlier by a suitable setting of the position of the cams).

Thereafter the pivotal movement of the stay 6 will not move the lever 7 from the position because its roller 7a is slidably rotated with attachment to the surface of the upstanding wall 6b, though the slightest movement of the lever 7 acts on the side plates 3 and 4 to move them inwardly.

The link 9 is propelled by the turning of the stay 6 which is transmitted thereto, and the pin 9b pushes the back covering plate 2 forward to the tilted down after the side covering plates 3 and 4 start to move to be folded down owing to the space between the pin 9b and the back plate 2.

Thus, only by a closing action of turning the front covering plate 1, the side covering plates and the back covering plate can be automatically closed making a pile of all of the covering plates.

In order to open the piled hood, the front plate 1 is raised by which the stay 6 is turned and the link 9 is retreated while the back covering plate 2 is released by the spring 10; the upper surface of the upstanding wall 6b of the stay 6 then leaves from the roller 7a setting the cam 6c free so that the lever 7 returns to the normal position being moved outwardly by the force of the spring 8 and the side plates 3 and 4 to be raised by the force of the spring 10.

The present invention has a simple construction as described above; it offers great convenience in handling a camera and enables easy and speedy opening and closure of the hood owing to the so called "one hand system construction" wherein only by bringing down the front plate 1 for the purpose of folding the hood the side covering plates 3, 4 and the back covering plate 2 are automatically folded in turn, and in order to raise the hood, only by raising the front plate 1, the other covering plates are automatically raised.

The embodiment according to the present invention described as above is only exemplary and, the present invention is not restricted by said embodiment and it can be changed within the scope of the invention, as defended by the appended claims.

Claims

What is claimed is:

1. A hood for a focusing screen of a camera comprising: a square frame; a square front covering plate; a square left side covering plate, a square right side covering plate and a square back covering plate, each of said plates being supported pivotally along one of their edges on each side of said square frame, a pair of stays, each of said stays being pivotally supported about an axis at one end portion thereof, on opposite sides of said frame and engaging at the other end portion with a side of said front covering plate to provide movement of said stays in response to a pivotable movement of said front covering plate, a cam surface formed on each of said stays, each cam surface being asymmetrical with respect to the other, a pair of levers, each of said levers being pivotally supported on one of said opposite sides of said frame and having a first surface engaging one of said cam surfaces and a second surface engaging a side covering plate, a pair of links each of said links being supported pivotally on one of said stays at a distance from said axis at an end portion thereof, a pair of pins each of said pins being formed on the other end portion of each of said links to engage said back covering plate, whereby said left side covering plate, said right side covering plate, and said back covering plate sequentially pivot to cover said frame in response to pivotal lowering of said front cover plate.

2. A hood for a focusing screen of a camera as in claim 1, wherein the lower portion of each of said stays is formed substantially in the shape of a semicircle having an upstanding peripheral wall, the lower surface of each of said walls being one of said cam surfaces, and wherein each of said first surfaces is provided a roller to cause movement of one of said levers whereby each of said levers presses the outer side of one of said side covering plates.

3. A hood for a focusing screen of a camera as in claim 2, wherein the upper portion of each of said stays has an elongated slot formed therein to engage a pin attached to said front covering plate at one of the opposite sides thereof so as to transmit a pivotal movement to each of said stays; in response to movement of said front cover plate, a first end portion of each of said links being pivoted on the semicircle portion of one of said stays, while the other end portion thereof is provided with a pin position so as to contact said back covering plate in response to movement of said links, each of said links being guided intermediate said end portions by a pin fixed to said frame.

4. A hood for a focusing screen of a camera as in claim 1, wherein the size of said front covering plate is a little larger than that of the other plates so that said side and back plates when folded are enclosed inside said front covering plate when said hood is in its closed position.