DE8708812U1 - Pneumatic release device for remotely operating camera shutters - Google Patents

Description

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G11517Gb

Mr. Tiejie YU, SONGSHAZHEN, Shangyu County, Zhejiang Province, PRC

Pneumatic release device for remote operation of camera shutters

j Description:

• The invention relates to a pneumatic release device for

Remote activation of camera shutters and in particular an improvement to such release devices.

There are various types of trigger devices for cameras,

for example, with a metal spring, electrically operated or 15

also pneumatically operated release devices.

A known pneumatic release device has a compressible and automatically returning to the original position

resetting air ball, one with one end to this air ball 20

connected air hose and a housing at the other end of the air hose, which is provided with an adapter that can be screwed onto the camera and which generates a pneumatic pressure generated by squeezing the air ball against a pressure in this housing.

_ arranged compression spring extending from the adapter release pin. 25

This well-known trigger device works as follows:

If the air ball is compressed by hand, the air escaping from it pushes a piston arranged in the housing forwards, so

that the readout pin connected to the piston closes the camera shutter 30

activated. If you let go of the air ball, the piston with the release button returns to its starting position under the influence of the compression spring that was tensioned during the release process.

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In this pre-designed pneumatic release device, the

Air ball/ the air hose, the housing and the piston that can be moved within it form a self-contained air space* In order to prevent the escape of air on the one hand and to ensure the necessary

g To ensure the piston can move in the housing, very precise fits between the piston and the housing are required.

Such a pneumatic release device for camera shutters has the following disadvantages:

Since the friction between the piston and the inner wall of the housing is high,

A very strong compression spring is required to overcome this friction in order to be able to return the piston to its original position. In addition, the pneumatic thrust required to operate the release device must be greater than the sum of the friction and the spring force.

Furthermore, in order to activate the camera shutter, the resistance of the shutter must be overcome. The required thrust depends on the compression ratio of the enclosed air, so that the air ball of the trigger device must be relatively large and the air hose must not be too long, otherwise the trigger device will not work satisfactorily and safely. In general, the air hose should be five meters long and not longer than six meters.

oe Since the tolerances between the inner wall of the housing and the outer circumference of the piston must be very high, it is difficult to machine these surfaces, which results in high costs.

To reduce frictional resistance, lubricants such as oil must be used. Since leakage of lubricant cannot be avoided, contamination by lubricants cannot be avoided.

The piston is subject to wear and abrasion, which promotes the leakage of lubricant and/or air. This in turn reduces the

Lifespan of the device. .../3

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^ In the ¹ known release device, the conical adapter is a relatively long* nipple/ which does not fit all camera types.

The invention is based on the object of creating a pneumatic release device for actuating camera shutters, which avoids the disadvantages mentioned above and ensures high operational reliability with a long service life in a simple and cost-effective manner.

The task is accomplished according to the invention with a pneumatic

Triggering device which has the features of claim 1. Advantageous embodiments of the invention are the subject of the subclaims.

., _ Instead of a piston guided in the housing, the invention uses a Io

bellows-like construction that is part of a self-contained air space that is formed from the manually compressible air ball, the air hose and the bellows. If the air ball is compressed, the bellows, which is designed as a bellows, is expanded and pushed forward in the housing, whereby the release pin attached to it extends out of the housing and can release the shutter of a camera. If the air ball is released, the pressure developed in the air system disappears and a pressure equalization with the ambient pressure takes place. The release pin returns due to the restoring force of the bellows itself and additional

__ spring force to the starting position in which it is inserted into the housing 25

has withdrawn.

In the release device according to the invention, the housing is not used as a part of the closed air space in which the

Adjusting the release pin allows the air pressure required to build up. This 3D

brings the following advantages:

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.The thrust required to drive out the release pin is quite small* Therefore, the air hose can be longer than previously possible and is generally nine meters long, but lengths of up to around thirty meters are possible. The longer length of the air hose

g enables a more cost-effective remote control of the camera. With the same length of the air hose, the release device according to the invention responds more precisely than previously known release devices which are provided with an actuating piston which can be moved in the housing-

It is just a relatively soft spring and a relatively

small air ball is necessary because no piston is needed. Accordingly, precise machining of the inner wall of the housing is unnecessary, and no lubrication is required. This leads to a significant reduction in costs.

The release mechanism has no wearing parts and has

accordingly, a longer service life. After a destructive test with over ten thousand working cycles, no air escape from the closed air system was detected. In addition, the bellows is very > . inexpensive and easy to replace.

In the drawing, an embodiment of the pneumatic release device according to the invention is shown schematically, namely

_ Fig. 1 is a partially sectioned view of a known pneumatic

Release device with adjustable piston guided in a housing,

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Fig. 2 a view as in Fig. 1 of a pneumatic release device according to the invention for remotely actuating camera shutters and

Fig. 3 shows a longitudinal section through the housing, which is made up of two parts and houses the release pin, the bellows used to adjust it, and the return spring, on an enlarged scale compared to Fig. 2.

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The preferred embodiment shown in Fig* 2 has a

Air bellows (1), an air hose (2) and a bellows (8) which are connected to one another, for example glued, and form a cavity filled with air which is gas-tight and encapsulated to the outside.

g The bellows (8) is located in a housing (3). At the front end of the bellows (8) there is a base (9) of a release pin (5) on which there is a pin (1Ö) serving as a release. The base (9) and pin (10) are firmly connected to one another to form a single component. A spring, in this case a soft one, is mounted on the pin (10).

^ _ Coil spring (u), aFiycörunct.

At the front end of the housing (3) or at the front housing part (12)

There is a short conical screw nipple (7) which is inserted into a connector a camera not shown for remote control of the camera shutter

can be screwed in. The screw nipple (7) is hollow so that 15

that the pin CiO) can extend out of it.

On the rear housing part (13) there is a tubular nozzle (11), which serves as an opening through which the air hose or part of the bellows (8) _ can protrude into the housing, as shown in Fig. 2. The bellows (8) is, for example, glued to the end of the air hose (2) assigned to it.

The housing (3) consists of two housing parts (12 and 13) which, as shown in Fig. 3, are connected to one another in such a way that the housing part (12)

_ can be rotated relative to the housing part (13). When attaching the 25

Housing (3) on a camera shutter, the front housing part (12)

be rotated in order to be able to screw it into or out of the camera adapter, while the rear housing part (13) with the bellows (8) housed in it and the connected air hose (2) is held in place because it should not be rotated.

The bellows (8) is circular in cross-section and has a folded side wall. Accordingly, the bellows (8) designed as a bellows can expand axially and contract elastically. Normally it is in the contracted state. The diameter of the bellows

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is smaller than the inner diameter of the housing (3) so that it can move smoothly and unhindered in the housing. The bellows (8) can be made of soft plastic, rubber or latex rubber, preferably it is made of soft plastic.

In contrast to a piston ( ⁴¹ ) provided in a previously known release device according to Fig. 1, the bellows (8) does not lie on the inner wall of the housing (3), so that this inner wall does not require any special processing.

The base (9) is designed as a flat, round plate. The diameter of this plate corresponds to that of the bellows (8), so that the base (9) is not guided on the inner wall of the housing (3), but can move freely in the housing. The base (9) can be made of metal, Hard rubber or hard plastic and is preferably made of hard plastic. The pin (10) is centrally attached to the base (9), for example welded, glued or manufactured in one piece with the base by injection molding or otherwise formed as one piece with it. The base (9) is preferably glued to the front end of the bellows (8). The spring (6), on the other hand, can be loosely attached to the pin.

If the air hose (2) is the same length in both versions, the air ball (1) in the version according to Fig. 2 can be smaller than in the release device according to Fig. 1, which has a slidably guided piston (4'). With a longer air hose (2), the air ball (1) must be chosen to be larger, just as the wall of the air hose (2) must be made thicker so that the air hose does not deform under the working pressure generated in the air system. Thus, if the air ball (1) is compressed, the air pressure generated thereby will have a full effect on the bellows (8) without any loss of pressure occurring*

. In addition, the head as a whole is shorter in the version equipped with a bellows (8) than in the version equipped with a piston (4 ¹ ), ie both the housing (3) and the conical screw nipple (7) are shorter, so that they are suitable for all types of cameras.

p. are, although some modifications may have to be made from case to case. Even if the camera's shutter release is located very close to the lens on the bottom right, the screwed-on head of the release device does not cover the camera's viewfinder.

In addition, the rear housing part (13) can be used

A conical coil spring (not shown in the drawing) must be attached to the pipe socket (11) to protect the air hose (2) against kinking and breakage.

The air ball (1) and the air hose (2) can be made of rubber, soft

plastic and latex rubber, while the housing (3) or its parts (12 and 13) can be made of hard plastic or metal. The conical screw nipple (7) is preferably made of metal.

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Claims (1)

&bull; ■ ■ a &igr; ···· · · · &igr; ta· ■■ *·· · · M ltt 11 ■> · · > _&tgr; G11517Gb Mr. Tiejie YU, SONGSHAZHEN, Shangyu County, Zhejiang Province, PRC Claims for protection: Λ. Pneumatic release device for remotely actuating camera shutters, with a compressible air ball, an air hose connected to it at one end and a housing provided at the other end of the air hose, which has an adapter that can be screwed onto the camera and contains a release pin that can be extended from the adapter by pneumatic pressure generated when the air ball is compressed, against a pressure spring arranged in it, characterized in that on the housing (3) 15 facing end of the air hose (2) an axially expandable bellows (<Ω) is connected which projects into the housing through an opening (11) located on the rear of the housing and which forms a closed air space with the air hose (2) and the air ball (1), and that the Release pin (5) is connected to the front end of the bellows (8). 20 2. Device according to claim 1, characterized in that the release pin (5) has a base (9) attached to the bellows (8) designed as a bellows and a pin (10) fastened to the base. 3. Device according to claim 1 or 2, characterized in that the bellows (8) consists of elastic material such as soft plastic, rubber or latex rubber. 4. Device according to one of claims 1 to 3, characterized in that the base (9) is made of a stable material such as metal, hard rubber or hard plastic. 5" Device according to one of claims 1 to 4, characterized in that the housing (3^ consists of two parts (12 and 13).
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