DK2597391T3 - Wall box with damper - Google Patents

Description

The invention relates to a wall sleeve with a guide pipe and a vent in the guide pipe and a cover positioned at the end of the guide pipe, which can move between a closed position and an open position, and on the inside of the cover a hyperbolically shaped flow body is constructed, with the cover running axially along guide arms in the guide pipe and with a guide body constructed as a streamlined, funnel-shaped ring attached to the cover, whereby internally, the funnel initially runs parallel to the central axis of the guide pipe and then opens out in such a way that it deflects the flow of air outwards from the central axis by 70°, and the cover, pushed by the flow of air in the guide pipe which is formed by the difference in pressure between the air pressure in the guide pipe and the external ambient air, opens and closes independently against a restoring force, thus guiding the flow of air to the edge of the cover and into the open air with a minimum loss in pressure.

Wall sleeves are used to ventilate rooms, particularly kitchens, by means of a ventilator and an outward guide pipe, which is closed with a cover. With the new German Energy Saving Act of 2009 (EnEV), which came into force on 10/01/2009, more stringent energy standards have been set for buildings. Wall sleeves that are permanently open do not meet the new standards for building impermeability. However, closed, airtight wall sleeves reduce heat loss to almost zero when the extractor hood is switched off.

This type of closed, airtight wall sleeve is disclosed in the patent specification EP 1921 394 Bl. The components of the wall sleeve system disclosed in that document with optimized airflow characteristics use the effects of airflow pressure that arise when the extractor hood is operated in combination with mechanically controlled spring and magnet forces when opening and closing the cover.

With the energy from the airflow, the cover automatically moves along the guide arms when it opens and the restoring force of a tension spring causes the cover to close automatically. Therefore, when the extractor hood is switched off, the cover closes flush against the wall sleeve making it airtight, meaning that no thermal bridge arises on the external wall. The wall sleeve system works without requiring an electrical energy supply because it does not use any electrically operated auxiliary devices. When it automatically opens, the cover's path of motion is limited by end stops on the vent in the guide pipe. A disadvantage of this is that the total kinetic energy contained by the cover and all the components directly connected to it due to its movement is more or less eliminated or dissipated within the wall sleeve when it hits the end stops. Particularly with very strong flows of air caused by powerful extractor hoods, this leads to very large forces of impact and therefore to problems with warping inside the structure of the wall sleeve's body, as well as to unpleasant noises.

The underlying task of this invention is therefore to create a generic wall sleeve in which the cover is relatively smoothly decelerated when it moves, thus dampening or preventing such an impact on the end stops on the guide pipe vent.

This task is fulfilled by the features of claim 1.

Embodiments of the invention are described in the subclaims.

In generic wall sleeves, the cover moves independently due to the energy of the airflow, whereby the cover runs axially along guide arms in the guide pipe. The path of motion of the cover and the flow body attached to the inside of it is limited due to an end stop on the guide pipe vent. The total kinetic energy contained by the cover and the flow body attached to the inside of it due to its movement is released when it hits the end stop on the wall sleeve system and is absorbed by this.

With the inventive wall sleeve, the cover's motion when opened is relatively smoothly decelerated by an additional braking force after an initial stopper towards the end of its path, and as a result, an impact on the end stop on the guide pipe vent is prevented or dampened.

Here, the restoring force is created using a tension spring on a swivel arm, which is mounted to the inside of the guide pipe by means of a hinge, and its path is limited on one side by the first stopper, the swivel arm stopper. The other side of the swivel arm is connected to the flow body via a connecting wire. This creates the restoring force for the cover.

The braking force is triggered by a spring which hits the central point of the flow body.

When the swivel arm hits the first stopper, the moving flow body is not abruptly stopped, but rather smoothly decelerated by a spring which absorbs the kinetic energy of the moving mass.

The width of the wall sleeve opening is determined by the end stop on the guide pipe vent, regardless of how strong the airflow is from the working extractor hood. After the swivel arm has reached the swivel arm stopper, the remaining energy is absorbed by the spring. If the spring does not absorb enough energy from the moving mass of the cover, then the cover will hit the end stop on the guide pipe vent at the end of its path at a correspondingly reduced speed.

In a preferred embodiment, the spring is a compression spring which is affixed in the internal hollow space of the flow body. Here, one end of the compression spring runs axially all the way through the cylindrical space inside the spring and is then connected to the swivel arm via the connecting wire, whereby one side of the swivel arm is attached to the internal wall of the guide pipe by means of a hinge. The tip of the hyperbolic surface at the center of the flow body has an opening through which this end of the compression spring protrudes. The opening in the flow body has a recess on the inside in which the opposite end of the spring rests.

The end of the compression spring that protrudes from the flow body is connected to the swivel arm. Consequently, the pre-loaded compression spring is compressed after the swivel arm stopper has been hit, thus absorbing the kinetic energy of the flow body, in a similar fashion to a damper. This dampens the impact on the end stops on the guide pipe vent and prevents the kinetic energy that would otherwise have been applied to the wall sleeve from being converted into damaging deforming forces or being passed onto other parts within the wall sleeve system.

However, the absorbed kinetic energy does not disappear in the compression spring, but instead is converted into a reverse motion of the flow body. The kinetic energy absorbed by the compression spring is thus reapplied in the cover's closing direction, against the flow of air. Here, the width of the wall sleeve's opening is adapted to the individual airflow of the extractor hood.

In another embodiment of the invention, the compression spring forms one unit with the connecting wire, i.e. it is made from one continuous piece of spring steel.

An advantage of the invention is that the compression spring decelerates the cover in the final part of its path of motion, thus preventing an impact on the end stop. This prevents the total kinetic energy absorbed by the impact from being passed on within the wall sleeve.

Below, the invention is explained using examples of preferred embodiments with reference to illustrations by way of example. These are:

Fig. 1: The cross section of a wall sleeve in the open position.

Fig. 2: The wall sleeve from Fig. 1 in the closed position.

Fig. 1 shows an advantageous embodiment of the inventive wall sleeve (1) in the open position, Fig. 2 shows wall sleeve 1 in the closed position. The wall sleeve (1) is presented with its guide pipe (2) in the wall (4). The cover (5), with the flow body (6) attached to the inside of it, is pushed into the open position by the flow of air (12) against a restoring force and is kept there whilst the extractor hood is switched on. The restoring force is applied by means of a pre-loaded tension spring (18), which is attached to a swivel arm (16), which in turn is fixed by means of the swivel bearing (17).

The swivel arm (8) can be moved as far as possible until one side (16) of the swivel arm (8) hits the first stopper (20). One side of stopper 20 is fixed firmly to the internal wall of the guide pipe (2). This determines the initial opening width of the wall sleeve (1) when the flow body (6) or the cover (5) hits the stopper (20).

The compression spring (21) is fitted to the inside of the flow body (6), whereby one end of the compression spring (21) rests in a recess on the inside of the flow body (6). The other end of the compression spring (21) is part of the connecting wire (9). In this way, the compression spring (21) absorbs the kinetic energy of the flow body (6) or the cover (5) when the swivel arm (8) hits the swivel arm stopper (20), and then reapplies it in the closing direction, opposite the flow of air (12), so that cover's motion, particularly in the final part of its path, is smoothly decelerated. Consequently, the opening width of the wall sleeve (1) adapts to the individual flow of air (12) from the extractor hood.

Reference numbers 1 Wall sleeve 2 Guide pipe 3 Ventilation pipe 4 Wall 5 Cover 6 Flow body 7 Guide arm 8 Swivel arm 9 Connecting wire 10 Spring 11 Seal 12 Airflow 13 Bearing 14 Guide body 15 Hyperbolic surface 16 Side of the swivel arm 17 Swivel bearing 18 Tension spring 20 First stopper, swivel arm stopper 21 Compression spring 30 Flange 31 Magnets 32 End stops

Claims (6)

A wall box with a guide tube and a vent opening on the guide tube (2) and a cover (5) disposed in the end of the stool tube and movable between a closed position and an open position, and on the inside of which a hyperbolic shaped flow body is formed (6), the cover being axially guided on guide arms in the guide tube (2), and then a guide member (14), which is configured to flow linearly as a funnel-shaped ring, the inside of the hopper initially extending parallel to a central axis of the guide tube (2) and then expands so that the air flow is deflected by approx. 70 ° outward from the center axis, and the cover (5), driven by the air flow in the guide tube formed by the pressure difference between the air pressure in the guide tube (2) and the outside ambient air, opens and closes automatically against a return force, thus directing the air flow to the cover (5). edge and out in the open with minimal pressure loss, characterized in that the return force is formed by a pulling spring (18) on a pivot arm (8) mounted on the inner wall of the guide tube (2), the path of which is limited to one side by the first stop (20), and the other side of which is connected to the flow body (6) via a connecting wire (9), and that the opening movement of the cover (5) is gently reduced after a first stop (20) by an additional braking force applied of a spring which grips the center of the flow body (6) and absorbs its kinetic energy, thereby preventing or attenuating a collision with the end stop (32). Wall box according to claim 1, characterized in that the spring is a compression spring (21) arranged in the interior of the flow body (6). Wall box according to claim 1, characterized in that the compression spring (21) is connected to the swivel arm (8) via the connecting wire (9). Wall box according to claim 1, characterized in that the kinetic energy absorbed by the spring is converted into a reciprocating movement of the flow body (6). Wall box according to claim 3, characterized in that the compression spring (21) forms a unit with the connecting wire. Wall box according to claim 1, characterized in that the spring delays the cover (5) on the last part of the exit movement.