DE8700338U1 - Gas spring - Google Patents

Description

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HANS TRAPPENbER ¹ GI \J*ai!eVtj:n$3 en ieur . Karlsruhe

EUROPEAN PATENT AGENT

18.12.1986 Ε/η VW 1288

&zgr; Ignaz Vogel GmbH & Co. KG, vehicle seats

Kleinsteinbacher Str. 42 - 44, 7500 Karlsruhe 41-Stu.

Gas spring

The innovation concerns a gas adjusting spring according to the generic term of claim 1.

A gas adjusting spring of this type is the subject of DE-GM 86 01 132. Such gas springs are used in particular in seating furniture, and here again preferably in passenger seats, in particular for adjusting the seat height or the angle of the backrest of such seats. They have the advantage that they do not make any noise when adjusted, that they are continuously adjustable, maintenance-free and can also be manufactured in an economical manner. With the gas springs that are well known and valued, it is sometimes felt to be a disadvantage that the adjustment path between the two adjustment positions (stroke) is strictly linear in

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Dependency on the actuating force exerted by the piston rod. In order to achieve a progressively increasing actuating force, a corresponding spring element must be installed outside when using such gas actuating springs.

The innovation has set itself the task of specifying a gas adjusting spring in which the aforementioned linear dependency is modified in such a way that the actuating force increases progressively at the end of each adjustment stroke.

This is achieved according to the innovation by the means specified in the characterizing part of claim 1. Further embodiments of these means are the subject of the subclaims.

The particular advantage of this solution is that the buffer element is housed within the structural unit gas spring, so it does not take up any additional space.

The innovation is explained in more detail below using the drawings. They show:

Fig. 1 a longitudinal section through such a gas spring and

Fig. 2 a displacement-force diagram for a gas spring according to the state of the art and according to the present innovation.

A cylindrical tube (1) is closed on both sides in a known manner via sealing pieces (2, 3) with seals (4, 5). The sealing piece (2) has a threaded hole (6) that allows the gas adjusting spring to be screwed onto any structural part. The sealing piece (3) is designed to allow a piston rod (7) to pass through.

drills. The seal (5) is continued to a sleeve seal (8) which rests on the piston rod (7). The piston rod (7) is connected to a piston (9) which divides the cylinder (10) into two cylinder chambers (11, 12).

A valve (15) is used to connect the two cylinder chambers (11, 12). This valve (15) is designed as a slide valve and is formed by a valve slide (16) together with a valve sleeve (17) and valve seals (18, 19) arranged on both sides of the valve sleeve (17). The valve sleeve (17) with its valve seals (18, 19) is held in a longitudinal bore (20) that is introduced into the piston rod (7) from the front side by a spacer ring (21). The valve slide (16) strikes a shoulder (22) of this longitudinal bore (20). A tappet (23) sits on the valve slide (16) and is guided outwards in the piston rod (7).

In Fig. 1, the slide valve is shown in the closed state. When the tappet (23) is pressed, the valve slide (16) is moved out of the area of the seal (18) so that hydraulic fluid from the cylinder chamber (11) can pass past the valve slide (16) through the holes (24, 25) into the cylinder chamber. The piston rod (7) can thus be moved within the cylinder (10); at the same time, the structural part screwed on via the threaded hole (6) can be moved, depending on the piston stroke into a position dependent on the direction of movement of the piston rod (7).

According to the state of the art, the adjustment force transmitted from the piston rod (7) to the structural part remains the same over the adjustment path - see Fig. 2, linear

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Curve X.

According to the present innovation, the piston (9) of the piston rod (7) in the cylinder (10) is connected in a force-fitting manner to one, if necessary also to both sealing pieces (2, 3) via an additional buffer element (25). The illustration according to Fig. 1 shows a buffer element (25) inserted between the piston (9) and the sealing piece (2) opposite the free side of this piston (9).

A buffer element (25) preferably made of an elastomer material, in particular a cellular polyurethane elastomer, is fixed between this sealing piece (2) and the piston (9). If the piston rod (7) is now moved by actuating the plunger (23), a progressive increase in force is caused by the buffer element (25) towards the end of an adjustment stroke of the piston rod (7) or of the screwed-on structural part, whereby the approach to or into the end position is dampened.

Curve Y in Fig. 2 shows this relationship between the adjustment force and the adjustment path. At the beginning of an adjustment stroke, this relationship is linear - analogous to curve X. As the end of the stroke is approached, the force increases progressively, the end of the stroke and thus the end position of the structural element are approached gently.

Regarding the structural solution according to Fig. 1, it should be noted that the force-locking connection between the

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When connecting the buffer element (25) and the piston (9), it must be ensured that the passage between the cylinder chambers (11, 12) is kept clear. For this purpose, the buffer element (25) is fixed to a bridge-like bracket (26) which keeps the longitudinal bore (20) clear and keeps the connection between the cylinder chambers (11, 12) open via at least one radial bore (27).

Claims (3)

HANS T RAPP ENl BE &bgr;&iacgr;&agr; \J* A.-ifVi ,!Engineer · Karlsruhe EUROPEAN PATENT REPRESENTATIVE 18.12.1986 Z/n VW 1288 Ignaz Vogel GmbH 6 Co. KG, vehicle seats Kleinsteinbacher Str. 42- 44, 7500 Karlsruhe 41-Stu. Gas-adjusting spring PROTECTED CLAIMS 1. Gas adjusting spring, which consists of a front-side formed by a cylinder sealed by means of sealing pieces, which is divided by a piston with an outwardly extending piston rod into two cylinder chambers, both of which are to be connected to one another via a valve in order to adjust the piston position,
characterized, that an outer seal (25) is inserted in the space between the piston (9) and at least one of the sealing pieces (2, 3). 2. Gas adjusting spring according to claim 1, characterized in that the buffer element (25) consists of an elastomer material. 3. Gas spring according to claim 3, characterized in that the elastomer material is a cellular polyurethane elastomer.