DE29915756U1 - Impact absorbers for furniture parts - Google Patents

Description

TERMEER STEINMEISTER & PARTNER GBR PATENTANWÄLTE - EUROPEAN PATENT ATTORNEYS

Dr. Nicolaus ter Meer, Dipl.-Chem. Peter Urner, Dipl.-Phys. Gebhard Merkle, Dipl.-Ing. (FH) Mauerkircherstrasse 45 D-81679 MUNICH

Helmut Steinmeister, Dipl.-Ing. Manfred Wiebusch

Artur-Ladebeck-Strasse D-33617 BIELEFELD

51

HENP06/98/2

9.9.1999

Paul Henke GmbH & Co. KG

Brückenstrasse 94

32584 wages

IMPACT ABSORBERS FOR FURNITURE PARTS

Priority:
11.09.1998 EN 298 16 341.1

Paul Henke GmbH & Co. KG · . .1 !*..! BBN P06 · / 9&/ 2 September 9, 1999

IMPACT ABSORBERS FOR FURNITURE PARTS

The invention relates to an impact damper for furniture parts, with a fastening part held in a recess in the furniture part and a buffer made of flexible material protruding from the recess. Such impact dampers serve, for example, as door buffers to dampen the impact of a door on the furniture body.

Conventional impact absorbers of this type are made from a single piece of plastic and are then inserted either by hand or by machine into a corresponding hole in the wall of the furniture body where the door strikes.

However, particularly when the impact absorber is assembled by machine, the material from which the impact absorber is made must not be too soft so that the fastening part can be pressed into the hole in the furniture part without any problems. Consequently, in conventional impact absorbers the buffer also has a hardness that is not always optimal in terms of the damping properties.

DE 90 05 286 Ul discloses an impact absorber that is made from plastic using a two-component process. The buffer is made of softer material and has the shape of a flat lens embedded in the front side of the fastening part. With this design, however, it is difficult to make the buffer sufficiently soft.

DE 298 02 093 Ul describes an impact absorber according to the preamble of claim 1, in which a dumbbell-shaped buffer made of soft material can be inserted into a fastening part which is formed by a hinged sleeve. After the sleeve is closed, the buffer is held in the sleeve with a form-fitting manner by a thickened base part. Although the thinner middle part of the buffer achieves greater flexibility, the length of this middle part is limited by the fact that the buffer with its thickened base part must be held sufficiently stable in the sleeve. In addition, with this impact absorber, opening and closing the sleeve requires additional manufacturing and assembly effort.

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The object of the invention is therefore to provide an impact absorber of the type mentioned at the outset which can be assembled easily and with high functional reliability, in particular by machine, and which nevertheless has good damping properties.
5

This object is achieved according to the invention in that the buffer is locked into the fastening part with a head part which is thicker than the foot or is formed integrally with the fastening part.

If the buffer is locked into the fastening part with a thickened head, it can be pressed into the fastening part from the front during assembly, so that the fastening part does not need to be opened. If the buffer is manufactured as a single piece using a two-component process, this assembly step is completely eliminated. In any case, however, the fact that the buffer rests on the base of the fastening part with its relatively thin foot means that a high degree of flexibility is achieved for a given length. Since the cross-section of the foot can be dimensioned without regard to the tear-out strength with which the buffer is held in the sleeve, the flexibility can be adapted to the respective requirements within a wide range.

Advantageous embodiments of the invention emerge from the subclaims.

Since the fastening part is harder than the buffer, a relative movement occurs between the fastening part and parts of the buffer during the impact.

If the part of the buffer which is movable relative to the fastening part is in frictional contact with the fastening part, part of the impact energy can be absorbed by friction, resulting in largely inelastic damping and thus preventing the door from springing back undesirably.

The foot can be designed in such a way that its cross-sectional area decreases towards the free end, so that a non-linear spring characteristic curve is achieved which is particularly advantageous for the damping behavior.
35

In the following, embodiments of the invention are described with reference to the drawings.

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tion is explained in more detail.

Show it:
Figure 1

a longitudinal section through an impact absorber according to a first embodiment;

Figure 2

a perspective view of a furniture part with an impact absorber mounted thereon;

Figures 2 and 3 show longitudinal sections through impact absorbers according to other embodiments;

Figures 5 to 7 show an impact absorber according to a further embodiment in two mutually perpendicular longitudinal sections and in plan view; and

Figures 8 and 9 show longitudinal sections through impact absorbers manufactured using the two-component process.

The impact damper 10 shown in Figure 1 consists of two parts, namely a fastening part 12 in the form of a pot-like sleeve and a piston-like buffer 14, which is slidably guided in the sleeve and has a projecting head part 16 that protrudes from the open end of the fastening part 12. The fastening part 12 is provided with a radially projecting circumferential collar 18 at the open end.

Figure 2 shows part of a wall 20 of a furniture body, against the front face 22 of which a door 24, shown in dash-dotted lines, strikes. The impact absorber 10 is mounted in the front face 22 of the wall 20 in such a way that it dampens the impact of the door 24.

The fastening part 12 of the impact absorber consists of a relatively hard plastic and is mechanically pressed with the aid of a suitable tool into a bore 26 provided for this purpose in the wall 20 until the collar 18 rests against the front surface 22.

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In the example shown, the protruding head part 16 of the buffer 14 has the shape of a solid cylinder and forms a slightly rounded stop surface 28 for the door 24. Within the fastening part 12, the buffer 14 forms a circumferential collar 30 which tapers conically towards the inner end of the buffer and forms a shoulder 32 on the back which engages behind a corresponding locking shoulder 34 on the inner surface of the fastening part. The buffer 14 can thus be pressed into the pot-shaped fastening part and locked into place with temporary elastic deformation of the collar 30. Since the tool used to press the fastening part 12 into the hole 26 can grip the collar 18, the buffer 14 can already be mounted in the fastening part 12 by the manufacturer before the impact absorber is attached to the wall 20 of the furniture body.

According to Figure 1, the inner end of the buffer 14 forms a foot 36 which tapers conically towards the free end and rests on the base 38 of the fastening part 12. When the door 24 impacts on the buffer 14, the latter is pressed deeper into the fastening part 12 and an elastic deformation of the tapered foot 36 initially occurs so that the impact is softly cushioned. Due to the conical shape of the foot 36, the deformation resistance increases progressively when the buffer is pressed deeper into the fastening part.

The collar 30 and/or the peripheral surface of the cylindrical part of the buffer is preferably in frictional contact with the inner surface of the fastening part 12. At least the radial play between the buffer 14 and the fastening part is so small that frictional contact occurs at the latest when the buffer is acted upon by the door 24 and is thereby axially compressed and simultaneously radially expanded. During the subsequent inward movement of the buffer in the fastening part, a significant portion of the impact energy is thus absorbed by friction, so that effective damping is achieved and springing back of the buffer and the door 24 is avoided.

The damping behavior of the impact absorber 10 can be optimized as required by the choice of material and geometry of the buffer 14. Figures 3 to 7 show alternative design options for the buffer 14.

In the embodiment according to Figure 3, the foot 36 of the buffer has the shape of a

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of a hose whose wall thickness increases in the direction of the projecting part of the buffer and whose interior continues in a cavity 40 in the projecting part of the buffer.

In the embodiment according to Figure 4, the foot 36 has the shape of a zigzag folded wall which acts like a compression spring and is supported by its foot plate 42 on the bottom of the fastening part 12.

In the embodiment according to Figures 5 to 7, the base 36 is formed by four cylindrical columns 44 and 46 which are arranged in the shape of a square in plan view (Figure 7). The columns 44 are longer than the columns 46 and are supported on the bottom of the fastening part 12 from the beginning, while the shorter columns 46 only come into contact with the bottom when the columns 44 have already deformed to a certain extent.
15

Figures 8 and 9 show examples of impact absorbers in which the soft elastic buffer 14 and the fastening part 12 are injection-molded in one piece from plastic using a two-component process. The base 38 of the fastening part is offset inwards relative to the end of this fastening part, so that the length of the buffer 14 can be selected independently of the total length of the fastening part 12 required for stable fastening.

In the embodiment shown in Figure 8, the foot 36 of the buffer is tubular and the wall thickness decreases towards the bottom of the fastening part, similar to Figure 3. This bottom 38 here has an opening 48 which allows the introduction of a mold core to form the cavity in the foot 36.

In the embodiment according to Figure 9, the foot 36 is solid. The part of the buffer 14 lying outside the fastening part 12 has the shape of a flat plate 50 which is supported on the collar 18 and forms a rounded projection 52 in the middle, the diameter of which is not larger than the diameter of the foot 36. In the event of an impact, the elastic deformation can therefore continue into the foot 36, so that a soft damping behavior is achieved. The material displaced during elastic deformation of the buffer can thereby give way radially within the projection 52, and the material of the foot 36 can axially deform with slight elastic deformation of the base 38.

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so that despite the limited volume elasticity of the material used for the buffer 14, a high degree of flexibility can be achieved.

By means of beads 54 formed on the inner wall of the sleeve-shaped fastening part 12, a firm connection between the fastening part and the injected buffer 14 is achieved.

In particular, the embodiments according to Figure 3 or 9 allow a very small design of the impact absorber. For example, here the outer diameter of the fastening part 12 (without the collar 18) has a diameter of only 5 mm, so that it fits into a 5 mm hole in a piece of furniture.

Claims (12)

1. Impact absorber for furniture parts, with a fastening part ( 12 ) in the form of a pot-like sleeve held in a recess ( 26 ) of the furniture part ( 20 ) and a buffer ( 14 ) protruding from the recess, which is supported by a foot ( 36 ) on the bottom ( 38 ) of the fastening part ( 12 ) and consists of a flexible material which is softer than the material of the fastening part ( 12 ), characterized in that the buffer ( 14 ) is locked in the fastening part ( 12 ) with a head part ( 16 ) which is thicker than the foot ( 36 ) or is formed integrally with the fastening part. 2. Impact absorber according to claim 1, characterized in that the part of the foot ( 36 ) which rests on the bottom ( 38 ) of the fastening part has a smaller cross-section than the head part ( 16 ) of the buffer. 3. Impact absorber according to claim 1 or 2, characterized in that upon elastic deformation of the buffer ( 14 ), parts of this buffer which move relative to the fastening part ( 12 ) are in frictional contact with the fastening part. 4. Impact absorber according to one of claims 1 to 3, characterized in that the buffer ( 14 ) has the shape of a piston which is displaceably guided in the fastening part. 5. Impact absorber according to one of claims 1 to 4, characterized in that the fastening part ( 12 ) has an outwardly projecting collar ( 18 ) at the open end. 6. Impact absorber according to one of the preceding claims, characterized in that the fastening part ( 12 ) and the buffer ( 14 ) are designed as separate components. 7. Impact absorber according to claim 6, characterized in that the foot ( 36 ) has the shape of a cone tapering towards the free end. 8. Impact absorber according to claim 6, characterized in that the foot ( 36 ) has the shape of a zigzag folded wall. 9. Impact absorber according to claim 6, characterized in that the foot ( 36 ) is formed by at least two columns ( 44 , 46 ) of different lengths, of which at least one ( 44 ) is constantly supported on the bottom of the fastening part, while at least one other ( 46 ) only comes into contact with the ground after deformation of the first columns. 10. Impact absorber according to one of claims 1 to 6, characterized in that the foot ( 36 ) has the shape of a tube. 11. Impact absorber according to claim 5, characterized in that the buffer ( 14 ) is supported with its outer peripheral edge on the collar ( 18 ) of the fastening part and has a projection ( 52 ) in the middle, the diameter of which is not larger than that of the foot ( 36 ). 12. Impact absorber according to one of the preceding claims, characterized in that the outer diameter of the sleeve-shaped fastening part ( 12 ) is not more than 5 mm.