AT17731U1 - furniture damper - Google Patents

Abstract

Furniture damper (16) for damping a movement of a movably mounted furniture part (3), comprising: - a housing (19), - at least one fluid chamber (19a) formed in the housing (19) and having a high-pressure side (HP) and a low-pressure side (LP ), - a damping fluid arranged in the fluid chamber (19a), - at least one piston (20) with at least one overload opening (30), - an overload safety device (25) arranged in the piston (20) with a closure element acted upon by an energy accumulator (20a). (20b), wherein the closure element (20b) closes the at least one overload opening (30) of the piston (20) below a specified threshold value of the pressure application on the piston (20) and above the specified threshold value of the pressure application on the piston (20) the at least an overload opening (30) of the piston (20) against the force of the force accumulator (20a) releases, with the release of the overload opening (30) a fluid-conducting connection (31) z between the high-pressure side (HP) and the low-pressure side (LP) of the fluid chamber (19a) is released, wherein the closure element (20b) has a cylindrical and/or a conical lateral surface (33a, 33b) and that the damping fluid is above the specified threshold value of the pressurization onto the piston (20) downstream of the overload opening (30) through the fluid-conducting connection (31) in an axial direction along the cylindrical and/or conical lateral surface (33a, 33b) of the closure element (20b) or in a radial direction from the cylindrical and/or conical lateral surface (33a, 33b) of the closure element (20b).

Description

description

The present invention relates to a furniture damper for damping a load

movement of a movably mounted furniture part, comprising:

- a housing,

- at least one fluid chamber formed in the housing with a high-pressure side and a low-pressure side,

- a damping fluid arranged in the fluid chamber,

- at least one piston with at least one overload opening, the piston being arranged displaceably in the fluid chamber in order to carry out a damping stroke and the high-pressure side and the low-pressure side of the fluid chamber being separated from one another by the piston, _

- A U-overload safety device arranged in the piston with a closure element acted upon by an energy accumulator, the closure element closing the at least one overload opening of the piston below a predetermined threshold value of a pressure application on the piston and above the predetermined threshold value of the pressure application on the piston opposing the at least one overload opening of the piston the force of the force accumulator releases, a fluid-conducting connection between the high-pressure side and the low-pressure side of the fluid chamber being released by the release of the overload opening.

Such furniture dampers are used, for example, to dampen a closing movement of movable furniture parts (drawers, doors or flaps) or movably mounted furniture fittings, so that loud slamming and damage to the furniture parts are prevented. The damping effect of the furniture damper is generated by the flow resistance of a damping fluid in a housing. When pressure is applied, the piston is displaced within the fluid chamber, with the damping fluid flowing through piston openings and/or through a gap formed between the piston and the inner wall of the fluid chamber from the high-pressure side to the low-pressure side. If the piston is subjected to excessive pressure, for example if it is misused, this can lead to so-called shock absorber pre-loading. In such an overload case, the damping fluid can no longer flow through the piston or past the piston to a sufficient extent. The increased pressure can then no longer be reduced by the damper, so that the piston or the piston rod attached to it stops abruptly or springs back.

[0003] Overload safety devices for furniture dampers are widely known, for example from the applicant's AT 12 633 U1. These overload protection devices usually have a ball acted upon by a spring, which in normal operation (i.e. below a specified pressure applied to the piston) closes an overload opening of the piston and which closes the Uoverload opening of the piston in an overload case (i.e. above the specified pressure applied to the piston). against the force of the force accumulator releases, whereby a fluid-conducting connection between the high-pressure side and the low-pressure side is released. By releasing this fluid-conducting connection, a larger quantity of damping fluid can be transported from the high-pressure side to the low-pressure side, so that the pressure in the furniture damper is quickly reduced and the housing of the furniture damper is prevented from bursting open.

When using a ball in the function of the closure element, however, it has been found that in an area located behind (i.e. downstream) of the ball, a dynamic pressure is built up which is sometimes greater than the fluid pressure in an area in front of (i.e. upstream). the ball is This can lead to the fluid pressure in front of the ball and the dynamic pressure behind the ball interacting with each other in the event of a U-overload, as a result of which the ball is subject to considerable oscillations. These vibrations of the ball lead to an undefined switching behavior of the Uoverload protection and to the piston rod juddering, which is also noticeable through unpleasant rattling noises.

The object of the present invention is to provide a furniture damper of the type mentioned while avoiding the disadvantages discussed above.

This is achieved according to the invention by the features of patent claim 1. Further embodiments of the invention are given in the dependent claims.

According to the invention, it is therefore provided that the closure element has a cylindrical and/or a conical lateral surface and that the damping fluid above the predetermined threshold value of the pressurization on the piston downstream of the overload opening through the fluid-conducting connection in an axial direction along the cylindrical and / or is guided past the conical lateral surface of the closure element or in a radial direction away from the cylindrical and/or conical lateral surface of the closure element.

In the event of an overload, the damping fluid is deflected by the cylindrical and/or conical lateral surface of the closure element in such a way that the dynamic pressure in an area located behind (i.e. downstream) the closure element is prevented or at least reduced in such a way that the dynamic pressure behind the closure element is less than is the fluid pressure occurring in front of the closure element. This measure ensures that the closure element has a defined switching behavior, so that the closure element is prevented from oscillating in a longitudinal direction of the piston and the associated bouncing of a piston rod in the event of Uoverload.

A “cylindrical lateral surface” of the closure element is not only to be understood as meaning circular-cylindrical shapes, but also basically all those cross-sectional shapes whose base surface can be displaced parallel to itself (i.e. oval, polygonal, cross-shaped, etc.). The conical lateral surface, on the other hand, can be pyramid-shaped, pointed conical, truncated conical or conical-convex at least in sections.

According to one embodiment it can be provided that the closure element is mounted limited movement relative to the piston in a longitudinal direction of the piston.

The closure element can be designed, for example, as a solid body. According to an alternative embodiment, the closure element can also be designed as a hollow body, preferably as a sleeve. The cavity of the closure element can namely be designed to at least partially accommodate the energy store, resulting in a very compact design.

Further details and advantages of the present invention result from the following description of the figures. It shows or shows:

1 shows a perspective representation of a piece of furniture with a furniture body and drawers mounted so as to be movable relative thereto,

[0014] FIG. 2 shows a drawer pull-out guide with a drawer rail, which is to be connected to a drawer side wall,

[0015] FIGS. 3a-3c a furniture damper in an exploded view and two enlarged detailed views of this,

[0016] FIGS. 4a, 45 of the furniture damper in a perspective cross-section and an enlarged detailed illustration thereof,

[0017] FIGS. 5a-5c the furniture damper in a perspective section as well as a first detailed view in normal operation and a second detailed view in an overload situation,

Fig. 6a-6d the piston with the piston rod in two different perspective views and two detailed views of this.

Fig. 1 shows a piece of furniture 1 with a cupboard-shaped furniture body 2, with movable furniture parts 3 in the form of drawers via drawer pull-out guides 4 relative to the furniture body.

pus 2 are movably mounted. The drawers each have a front panel 5 , a drawer bottom 6 , drawer side walls 7 and a rear wall 8 . The drawer pull-out guides 4 each comprise a carcass rail 9, which is to be fastened to the furniture carcass 2 via fastening sections 12a, 12b, a drawer rail 10 which is movably mounted relative to the carcass rail 9 and which is connected or is to be connected to the drawer side wall 7, and optionally a center rail 11 which is movably mounted between the body rail 9 and the drawer rail 10 to realize a full extension of the drawer.

2 shows a drawer pull-out guide 4 and a drawer side wall 7 to be connected to the drawer rail 10 in a perspective view. A movable center rail 11 is arranged between the drawer rail 10 and the body rail 9, with a coupling element 13 being arranged on the drawer rail 10, which can be detachably coupled to a spring-loaded driver 14 of a retraction device 15, so that the drawer rail 10 can be released from the driver 14 towards the end of the closing movement detected and can be retracted into a closed end position by an energy accumulator of the retraction device 15 . This spring-assisted retraction movement of the drawer rail 10 can be braked up to the closed end position by a furniture damper 16, which is yet to be described, with a preferably hydraulic piston-cylinder unit.

The drawer side wall 7 is designed as a hollow chamber profile with an inner profile wall 7a and an outer profile wall 7b, the drawer side wall 7 having a downwardly open channel 17 extending in the longitudinal direction of the drawer side wall 7 for receiving the drawer rail 10. The drawer side wall 7 also has a first fastening device 38a for connecting to the rear wall 8 , a second fastening device 38b for connecting to the front panel 5 and a support 18 for supporting the drawer bottom 6 .

3a shows the furniture damper 16 in an exploded view. The furniture damper 16 has a cylindrical housing 19, for example, in which a fluid chamber 19a for the displaceable mounting of a piston 20 is formed. The piston 20 is connected to a piston rod 21 led out of the housing 19, the piston 20 being slidably mounted within the fluid chamber 19a in a longitudinal direction (L) of the piston rod 21 between a first end position and a second end position. When executing a damping stroke, the piston 20 can be braked against the resistance of a preferably hydraulic damping fluid located in the housing 19 . The piston 20 can be made in one piece or in several pieces. A volume of the fluid chamber 19a can be changed by moving the piston rod 21 between the first end position and the second end position, a deformable or movable compensation device 23 being provided to compensate for the volume of the fluid chamber 19a. At least one stabilizing element 24 with an opening 24a for slidably receiving the piston rod 21 is arranged in the fluid chamber 19a in a region between the first end position and the second end position, so that the piston rod 21 when the damping stroke is being carried out in a direction transverse to the longitudinal direction (L) the piston rod 21 extending direction can be stabilized. In this way, the piston rod 21 is guided precisely in the longitudinal direction (L), with a bending or buckling of the piston rod 21 being prevented during a movement in the longitudinal direction (L). A closure part 22 is provided for fluid-tight closure of the fluid chamber 19a.

Figure 3b shows the circled area (A) in Figure 3a in an enlarged view. The compensation device 23 can either comprise a compressible piece of material (e.g. foam rubber) or alternatively—as shown in the figure—a seal 23c which can be acted upon by a compression spring 23a and which is slidably mounted along the piston rod 21 within the fluid chamber 19a. The seal 23c can be supported on a bearing part 23b in relation to the compression spring 23a. The size of the opening 24a of the preferably disk-shaped stabilizing element 24 essentially corresponds to a diameter of the piston rod 21. The stabilizing element 24 rests at least in regions on an inner wall of the fluid chamber 19a and has at least one, preferably peripheral, recess 26a for the passage of the fluid in the fluid chamber 19a arranged damping fluid. in the

In the exemplary embodiment shown, the stabilizing element 24 is provided with two or more recesses 26a, 26b, 26c for the passage of the damping fluid. The stabilizing element 24 can be mounted either stationary within the fluid chamber 19a in a region spaced between the two end positions of the piston 20 or also so that it can be moved to a limited extent in the longitudinal direction (L).

Figure 3c shows the circled area (B) in Figure 3a in an enlarged view. The piston 20 has two piston parts 20c, 20d connected to one another and an overload safety device 25 with a closure element 20b, the closure element 20b being acted upon by an energy accumulator 20a in the form of a compression spring. The closure element 20b has a cylindrical lateral surface 33a and/or a conical lateral surface 33b. The piston 20 is provided with at least one U-overload opening 30 (FIG. 4b), which is closed by the closure element 20b below a predetermined pressure loading on the piston 20. Above the predetermined pressurization of the piston 20, the closure element 20b is moved counter to the force of the force accumulator 20a, so that the overload opening 30 of the piston 20 is released for the passage of the damping fluid in the case of Uoverload. In this way, a rapid pressure reduction in the fluid chamber 19a is brought about without the housing 19, the piston 20 or any other component of the furniture damper 16 being damaged. At least one piston opening 34 (Fig. 5b) is closed by a switching ring 20e, which can be moved relative to the piston parts 20c, 20d, during the execution of the damping stroke, so that the piston 20 has a high flow rate to the damping fluid when it moves in direction 29 (Fig. 4a) of the damping stroke opposes resistance. In the event of a movement counter to the direction 29 of the damping stroke, on the other hand, the switching ring 20e is moved into a position in which the piston opening 34 is uncovered, so that the piston 20 only offers a slight resistance to the damping fluid and the piston rod 21 quickly exits the housing again 19 can be pulled out.

4a shows the furniture damper 16 in a perspective cross section. A fluid chamber 19a for slidably supporting the piston 20 is formed in the housing 19 . Flow channels 27a, 27b, preferably in the form of grooves, arranged on the inner wall of the housing 19 allow the damping force to be controlled as a function of the path. The flow channels 27a, 27b can be designed in such a way that the effective flow cross section decreases in the direction 29 of the damping stroke. In this way, the further the piston 20 is pushed into the housing 19, the higher the flow resistance of the damping fluid and thus the damping force. The piston rod 21 is guided through the closure part 22, through the compression spring 23a, the bearing part 23b and the seal 23c of the compensation device 23 and through the stabilizing element 24 and is connected to the piston 20.

FIG. 4b shows the area framed in FIG. 4a in an enlarged view. When the piston 20 moves in the direction 29 of the damping stroke, the piston rod 21 is pushed into the fluid chamber 19a, with the additional volume of the piston rod 21 being able to be compensated for by the compensation device 23 . This is achieved in that the seal 23c moves against the force of the compression spring 23a when the piston rod 21 is pushed into the fluid chamber 19a, which increases the volume of the fluid chamber 19a and thereby compensates for the additional volume of the piston rod 21. In the exemplary embodiment shown, the stabilizing element 24 can only be moved to a limited extent within the fluid chamber 19a over a first partial path S1, with the housing 19 having a stop surface 28 for limiting a movement of the stabilizing element 24. In the exemplary embodiment shown, the stop surface 28 is formed by a narrowing of the fluid chamber 19a, the narrowing forming an annular inclined surface. In this way, the stabilizing element 24 is mounted in a displaceable manner only along the first partial path S1. The flow channels 27a, 27b are arranged along a second partial path S2, with the stop surface 28 preventing entry and thus possible jamming of the seal 23c with the flow channels 27a, 27b.

The fluid chamber 19a has a high pressure (HP) side and a low pressure (LP) side,

which are separated from each other by the piston 20. During the execution of the damping stroke in direction 29, the piston 20 is pressed into the high-pressure side (HP) of the fluid chamber 19a. If the pressurization of the piston 20 exceeds a predetermined threshold value, the overload protection device 25 becomes effective. For this purpose, the piston 20 has at least one overload opening 30, which is closed by the closure element 20b during normal operation (i.e. below the specified pressure loading on the piston 20). If the predetermined pressure loading on the piston 20 is exceeded, the closure element 20b is moved counter to the force of the energy accumulator 20a, so that the overload opening 30 of the piston 20 is released. By releasing the overload opening 30, a fluid-conducting connection 31 between the high-pressure side (HP) and the low-pressure side (LP) is released, so that the effective flow cross-section for the damping fluid is increased and the damping fluid, starting from the high-pressure side (HP), through the overload opening 30 and through a discharge channel 36 of the fluid-conducting connection 31 to the low-pressure side (LP) flows. In this way, a rapid pressure reduction in the fluid chamber 19a is brought about.

5a shows the furniture damper 16 in a perspective section. The high-pressure side (HP) and the low-pressure side (LP) of the fluid chamber 19a are separated from one another by the piston 20, the piston 20 being able to be pushed into the housing 19 in the direction 29 when the damping stroke is being carried out.

FIG. 5b shows the area framed in FIG. 5a in an enlarged view, the piston 20 being moved in the direction 29 below a predetermined threshold value of pressurization during the execution of the damping stroke (normal operation). In this case, the overload opening 30 of the piston 20 is closed by the closing element 20b by the force of the energy accumulator 20a. Starting from the high-pressure side (HP), the damping fluid flows through the piston part 20d and reaches the low-pressure side (LP) through at least one piston opening 34, so that the movement of the piston 20 is braked. In the exemplary embodiment shown, the piston 20 has a first piston part 20d and at least one second piston part 20c connected to the first piston part 20d. The first piston part 20d has a first recess 37a, in which the closure element 20b is at least partially accommodated. The second piston part 20c has a second recess 37b, in which the force accumulator 20a is at least partially accommodated. It can be provided that a longitudinal direction of the first recess 37a of the first piston part 20d and a longitudinal direction of the second recess 37b of the second piston part 20c run coaxially to one another. The second piston part 20c is connected to the piston rod 21, which is led out of the housing 19 of the furniture damper 16. The closure element 20b can be embodied as a hollow body, for example as a sleeve, with the energy accumulator 20a embodied as a compression spring being at least partially accommodated in a cavity 39 of the closure element 20b. It is preferably provided that the length of the closure element 20b corresponds to at least twice the diameter of the closure element 20b.

FIG. 5c, on the other hand, shows the area framed in FIG. 5a in an enlarged view, the piston 20 being moved in direction 29 when the damping stroke is carried out above a predetermined threshold value of a pressurization. In this case of overload, the closing element 20b is pressed by the occurring fluid pressure against the force of the energy accumulator 20a, so that the overload opening 30 of the piston 20 is released. In the event of an overload, the damping fluid on the high-pressure side (HP) therefore flows through the overload opening 30 of the piston 20, with the damping fluid flowing through the fluid-conducting connection 31 in the direction of the arrow 35 shown downstream of the Uoverload opening 30 along the cylindrical and/or conical lateral surface 33a, 33b of the closure element 20b in an axial direction or in a radial direction away from the cylindrical and/or conical lateral surface 33a, 33b of the closure element 20b. The fluid-conducting connection 31 can have, for example, at least one bore arranged in the piston 20 or at least one discharge channel 36 with a longitudinal direction, the longitudinal direction of the discharge channel 36 running transversely, for example at right angles, to a longitudinal direction (L) of the piston 20. Due to the cylindrical and/or conical lateral surface 33a, 33b of the

Closing element 20b, in the event of an overload, the damping fluid can be deflected downstream of the overload opening 30 in such a way that a dynamic pressure occurring behind the closing element 20b and an undesired oscillation of the closing element 20b in the longitudinal direction (L) are avoided.

The closure element 20b can have at least one throttle opening 32, preferably arranged coaxially with the overload opening 30, for the passage of the damping fluid. This throttle opening 32 serves to stabilize the piston 20, in particular shortly before reaching the depressed end position. The damping effect of the piston 20 can, as shown and described in FIG. 4a, be designed in several stages. A movement of the piston 20 can be damped over a first section through the first flow channel 27b, over a second section through the second flow channel 27a and over a third section through the throttle opening 32 up to the depressed end position. The damping fluid flows via the throttle opening 32 into the recesses 37a, 37b of the piston 20 and then, starting from the recess 37b of the second piston part 20c, reaches the low-pressure side (LP) of the fluid chamber 19a.

6a shows the piston 20 with the piston rod 21 connected thereto in a first perspective view. FIG. 6b shows the circled area in FIG. 6a in an enlarged view. The first piston part 20d and the second piston part 20c can be seen, between which the switching ring 20e and the closure element 20b are mounted so that they can be displaced to a limited extent. The second piston part 20c is provided with at least one discharge channel 36 through which the damping fluid can escape in the event of an overload.

6c shows the piston 20 with the piston rod 21 connected thereto in a second perspective view. FIG. 6d shows the circled area in FIG. 6c in an enlarged view. The second piston part 20c has a plurality of piston openings 34, preferably on the circumference, for the damping fluid to pass through.

Although the furniture damper 16 was shown in FIG. 2 in combination with a furniture fitting in the form of a drawer pull-out guide 4, it is immediately obvious that the furniture damper 16 can also be used in combination with a retaining plate for mounting the furniture damper 16, with a Furniture hinge or with a furniture drive for moving a movably mounted furniture part 3 can be used.

Claims (16)

Expectations 1. Furniture damper (16) for damping a movement of a movably mounted furniture part (3) comprising: - a housing (19), - at least one fluid chamber (19a) formed in the housing (19) with a high-pressure side (HP) and a low-pressure side (LP), - a damping fluid arranged in the fluid chamber (19a), - At least one piston (20) with at least one overload opening (30), wherein the piston (20) is slidably arranged in the fluid chamber (19a) to carry out a damping stroke and that the high-pressure side (HP) and the low-pressure side (LP) of the fluid chamber ( 19a) are separated from each other by the piston (20), - A U-overload safety device (25) arranged in the piston (20) with a closure element (20b) acted upon by an energy accumulator (20a), the closure element (20b) opening the at least one U-overload opening (30 ) of the piston (20) closes and above the specified threshold value of the pressurization of the piston (20) releases the at least one U-overload opening (30) of the piston (20) against the force of the energy accumulator (20a), whereby the release of the overload opening (30 ) a fluid-conducting connection (31) between the high-pressure side (HP) and the low-pressure side (LP) of the fluid chamber (19a) is released, characterized in that the closure element (20b) has a cylindrical and/or a conical lateral surface (33a, 33b) and that the damping fluid above the predetermined threshold value of the pressurization of the piston (20) downstream of the overload opening (30) through the fluid-conducting connection ( 31) in an axial direction along the cylindrical and/or conical lateral surface (33a, 33b) of the closure element (20b) or in a radial direction away from the cylindrical and/or conical lateral surface (33a, 33b) of the closure element (20b). will. 2, furniture damper according to claim 1, characterized in that the closure element (20b) relative to the piston (20) in a longitudinal direction (L) of the piston (20) is mounted to be movable to a limited extent. 3. Furniture damper according to claim 1 or 2, characterized in that the closure element (20b) is designed as a hollow body, preferably as a sleeve. 4. Furniture damper according to one of claims 1 to 3, characterized in that the closure element (20b) has a cavity (39) in which the force accumulator (20a) is at least partially accommodated. 5. Furniture damper according to one of claims 1 to 4, characterized in that the closure element (20b) has at least one throttle opening (32) for the passage of the damping fluid, preferably arranged coaxially to the Uoverload opening (30). 6. Furniture damper according to one of claims 1 to 5, characterized in that the piston (20) has at least one piston opening (34) through which the damping fluid flows, starting from the high-pressure side (HP) to the low-pressure side (LP). 7. Furniture damper according to Claim 6, characterized in that the fluid-conducting connection (31) released when the overload opening (30) is released has at least one bore or a discharge channel (36 ) having a longitudinal direction, the longitudinal direction of the discharge channel (36) running transversely, preferably at right angles, to a longitudinal direction (L) of the piston (20). 8. Furniture damper according to one of claims 1 to 7, characterized in that the piston (20) has a first piston part (20d) and at least one with the first piston part (20d) connected to the second piston part (20c). 9. Furniture damper according to claim 8, characterized in that the first piston part (20d) has a first recess (37a) in which the closure element (20b) is at least partially accommodated. 10. Furniture damper according to claim 8 or 9, characterized in that the second piston part (20c) has a second recess (37b) in which the force accumulator (20a) is at least partially accommodated. 11. Furniture damper according to claim 10, characterized in that a longitudinal direction of the first recess (37a) of the first piston part (20d) and a longitudinal direction of the second recess (37b) of the second piston part (20c) run coaxially to one another. 12. Furniture damper according to one of claims 8 to 11, characterized in that the second piston part (20c) is connected to a piston rod (21). 13. Furniture damper according to claim 12, characterized in that the piston rod (21) is led out of the housing (19) of the furniture damper (16). 14. Furniture damper according to claim 12 or 13, characterized in that the piston rod (21) can be displaced between a first end position and a second end position in order to carry out the damping stroke, with the fluid chamber (19a) being in a position between the first end position and the second end position arranged area at least one stabilizing element (24) with an opening (24a) for the displaceable accommodation of the piston rod (21) is arranged, so that the piston rod (21) during the execution of the damping stroke in a direction transverse to the longitudinal direction (L) of the piston rod (21). Direction can be stabilized. 15. Furniture damper according to one of claims 1 to 14, characterized in that the force accumulator (20a) has at least one helical spring, preferably a compression spring. 16. Furniture fitting, in particular drawer pull-out guide (4), with at least one furniture damper (16) according to one of claims 1 to 15. 6 sheets of drawings