ACTIVELY DYNAMIC SEATING FURNITURE

Abstract

The invention relates to a spring strut (1) for a pendulating chair (100) comprising a central cylindrical middle shaft (10) which is mounted in an axially displaceable manner on a plurality of guide elements (30) in a shaft cage (20) which can be received in a cylindrical securing sleeve (40) having an inner jacket (41), wherein the guide elements (30) each have a spring body (31) on which resilient support arms (32), each with a clamping contour (K), are provided, and a caster (34) which is mounted rotatably on a shaft (33), wherein the shaft cage (20), for resilient mounting of the spring bodies (31), forms respective recesses (21) in each of which a spring body (31) is mounted with clamping, and the respective spring body (31) bears with clamping with its clamping contour (K) on a mating contour on the shaft cage (20).

Description

BACKGROUND

The invention relates to seating furniture, particularly to active dynamic seating furniture. The invention relates in particular to active dynamic seating furniture with an improved spring strut.

Various types of seating furniture are known in the prior art which are designed such that the body sits in the most anatomically comfortable position possible by virtue of appropriately designed seats and backrests. Although such seating furniture is often perceived as pleasant and comfortable, it has substantial disadvantages. Sitting on such seating furniture involves passive sitting, which means that the muscles in the back are subjected to little to no stress and the intervertebral discs are subjected to static pressure. This can lead to wear and tear in the intervertebral disc, degeneration of the back muscles, and harm to health, as well as pain.

For this reason, dynamic, in particular active dynamic, seating devices have been developed which, in contrast to passive sitting, enable active dynamic sitting. During active dynamic sitting, the back muscles and the intervertebral discs are always slightly in action. When sitting on an active dynamic seating device, the seat user is required, for example, to balance the body and to perform pendular movements of the seat, as well as to perform vertical oscillations in order to simulate the “up-and-down” movement that occurs during walking and running.

Office chairs, for example, are offered in the form of pendulating stools. One well-known pendulating stool is known on the market under the name Swopper. Office chairs are often provided with a star-shaped base with a roller at each end. The mobility of the office chair is substantially limited to a height adjustment using a gas spring and the suspension of the backrest or seat. There are also complex mechanical systems that are expensive to manufacture and sometimes too complex and only allow dynamic sitting to a limited extent.

A pendulating stool is known from EP 0 808 116 in which the pendular movement is made possible by a rubber element that is arranged between the foot part and the leg part. The foot part consists of an open ring that is attached to the leg part via a radially extending cross member in such a way that the leg part is held substantially at the predetermined position, usually in the center of the slotted ring. With this stool, a provision is made that, during a pendular movement that takes place as a result of the rubber joint that is installed between the leg part and the radial cross member, a support movement takes place at the same time via a rubber buffer on the floor.

In order to make an up-and-down movement possible which is useful for dynamic loading of the spine, the pendulating stool from the prior art also has a spring, such as a coil spring, for example, in or on the leg part.

Utility model DE 731114 describes an active dynamic seating device with a seat part that is connected to a support shaft via a first tilting joint, the support shaft in turn being articulated to the foot part of the seat device by means of a second tilting joint. Each tilting joint preferably consists of a dome which is formed at the end of the support shaft and guided in a hollow cylinder and acted upon by a coil spring that is arranged in the hollow cylinder.

SUMMARY

Advantageous aspects of example embodiments of the present invention are described in the present disclosure wherein the quality and the active dynamic seating experience require the moving parts to have an especially efficient and durable design. In particular, play-free swinging, which should also be noiseless, is an aspect of example embodiments of the present invention. These properties are to be ensured not only during vertical deflection, but also during pendular movements involving deflection of up to at least 15°.

Aspect of example embodiments of the present invention overcome the known disadvantages of pendulating stools and chairs and provide an improved design for the spring strut.

Advantageous aspects of example embodiments of the present invention are achieved by the combination of features according to claim 1.

According to example embodiments of the present invention, a spring strut for a pendulating chair is proposed which comprises a central cylindrical middle shaft which is mounted in an axially displaceable manner on a plurality of guide elements in a shaft cage which can be received in a cylindrical securing sleeve having an innerjacket, wherein the guide elements each have a spring body on which resilient support arms, each with a clamping contour, are provided, and a caster which is mounted rotatably on a shaft, wherein the shaft cage, for resilient mounting of the spring bodies, forms respective recesses (openings) in each of which a spring body is mounted with clamping, and the respective spring body bears with clamping with its clamping contour on a mating contour on the shaft cage.

The specific design of the spring bodies ensures that the casters are supported under tension against the center shaft in their clamping state. The length, shape, and form of the spring arm is selected such that the desired freedom of play is achieved at a certain spring force.

An advantageous design of the example embodiments makes a provision that the clamping contour is embodied as a holding lug which protrudes from the support arm and preferably forms a contact surface or an undercut on one side. Advantageously, the mating contours on the shaft cage which are provided for the purpose of clamping a support arm are each instantiated by an edge at the respective recess, particularly an edge that points inward toward the center, namely on the edge that forms the transition from the inner surface of the shaft cage to the side surface of the respective recess.

It is also advantageous if the recesses for receiving a spring body each have a substantially rectangular central opening cross section which is adjoined by two laterally diametrically opposed and circumferentially extending recess regions for receiving the support arms, which recess regions in particular have a lower height when viewed in the axial direction in comparison to the height in the region of the central opening cross section.

In an advantageous embodiment of the invention, a provision is made that the central shaft has a portion at one end for attachment to or in a pendulum joint.

In a likewise advantageous embodiment of the invention, a provision is made that a first set of guide elements (e.g., four guide elements) is mounted in recesses that are arranged in the circumferential direction in a first (lower) assembly region (lower assembly level) of the shaft cage.

Spaced apart therefrom in the axial direction is a second set of guide elements (e.g., also four guide elements) which is mounted in an upper assembly region in additional recesses that are arranged in the circumferential direction. This results in two radially circumferential bearing portions for the center shaft which are spaced apart from one another in the axial direction and thus contribute to a play-free and low-noise supporting of the center shaft.

Example embodiments of the present disclosure provide a technical solution that is also advantageous in which three or four guide elements are respectively arranged in the circumferential direction on a common mounting plane of the shaft cage, preferably at positions with an angular interval of 120° or 90°. For example, if there are four guide elements, these can be distributed in the circumferential direction at the 3 o'clock, 6 o'clock, 9 o'clock, and 12 o'clock positions.

In another advantageous embodiment of the invention, a provision is therefore made that the recesses have openings through which the resilient support arms extend with at least one portion.

It is also preferred if two support arms on diametrically opposed sides of the spring body are each integrally connected to the spring body via an arc portion and these extend radially outward when the spring body is in the assembled state.

It is also advantageous if the bearing portion of the spring body is embodied as a partially cylindrical surface, preferably with a radius of curvature that corresponds to the radius of the cylindrical inner jacket of the securing sleeve and the spring bodies in the assembled state are arranged completely within the envelope of the shaft cage spanned by the outer jacket.

It is also advantageous if, in addition to the respective recesses, bearing blocks are provided on the shaft cage as counter-bearings for the resilient support arms in such a way that the support arms are resiliently supported against the same with a lateral bearing surface that faces away from the respective spring body when the guide elements are inserted through the securing sleeve into their assembly position. The support arms are compressed from their preassembly position. The desired spring force can be achieved on the basis of the spring geometry, material, and spring properties of the spring arms.

Another aspect of example embodiments of the present invention relates to a pendulating chair with a seat part and a foot part on which a pendulum joint is arranged and a spring strut which is equipped with a coil spring and designed with the aforedescribed features, the spring strut being attached at one end to the pendulum joint.

In addition to the spring strut, another aspect of the present invention relates to the method for assembling such a spring strut comprising at least the following steps:

• • a. mounting of the plurality of guide elements from the outside through the openings or the recesses of the shaft cage such that the casters of the guide elements are each aligned toward the intended position of the center shaft, and
  • b. clampingly locking-together of the guide elements (30) with their support arms (32) against the mating contour on the shaft cage (20).

The center shaft is preferably then inserted. In particular, by virtue of this clever design of the shaft cage, the guide elements remain in their intended clamping position even without the center shaft.

BRIEF DESCRIPTION OF DRAWINGS

Other advantageous refinements of the invention are characterized in the subclaims and/or depicted in greater detail below together with the description of the preferred embodiment of the invention with reference to the figures, of which:

FIG. 1 shows a perspective view of a guide element according to the invention in an unassembled configuration;

FIG. 2 shows a perspective view of the guide element according to the invention according to FIG. 1 in the assembled position;

FIG. 3 shows a sectional view of a guide element according to the invention in an unassembled configuration;

FIG. 4 shows a sectional view of a guide element according to the invention in the assembled situation;

FIG. 5 shows a perspective rear view of the guide element according to the invention from FIG. 2;

FIG. 6 shows a side view of a spring strut according to the invention;

FIG. 7 shows a cross section along the sectional plane A-A through FIG. 6;

FIG. 8 shows a sectional view through the spring strut according to FIG. 6;

FIG. 9 shows a sectional view along the sectional plane B-B through FIG. 6;

FIG. 10 shows a configuration of the parts of the shock absorber according to the invention in a preassembly position; and

FIG. 11 shows a sectional view through the sectional plane A-A of FIG. 10 in order to depict the assembly of the guide elements.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The example embodiments of the present invention will be explained in greater detail below with reference to FIGS. 1 to 11, with same reference symbols in the figures indicating same functional and/or structural features.

FIGS. 1 to 5 first show various views of the guide elements 30. The guide elements 30 each have a spring body 31 on which two resilient support arms 32 are provided. Furthermore, a shaft 33 on which a rotatably mounted caster 34 is mounted is attached to the spring body 31.

The two resilient support arms 32 have a portion 32a which, in the assembled state, extends through the openings in the shaft cage 20, as shown in FIG. 9. The support arms have the clamping contour designated as K in FIG. 4. This clamping contour K forms at least the outwardly projecting lug 37. With this lug 37, the support arm 32 clamps against the inner edge 24 of the respective recess 21 in the assembled state, as can be clearly seen in the configuration of FIG. 11 (before assembly) and FIG. 9 (after assembly).

FIG. 5 shows a perspective rear view of the guide elements 30 in order to illustrate the portion 35. The portion 35 of the spring body 31 is bent “convexly” for this purpose, being embodied namely as a partially cylindrical surface with a radius of curvature that corresponds to the radius of the cylindrical shaft cage, so that the spring body 31, as can be seen in FIG. 9, is arranged within the envelope of the outer jacket of the shaft cage 20 in the assembled state.

FIG. 6 shows a side view of a spring strut 1. The spring strut 1 comprises a central cylindrical center shaft 10 which is supported in an axially movable manner in a shaft cage 20 on the upper and lower guide elements 30. Four guide elements 30 are arranged in each assembly level M1, M2.

The securing sleeve 40 is arranged around the shaft cage 20 and accommodates the shaft cage 20 with the guide elements 30. In the assembled state, the guide elements 30 all abut against the cylindrical inner jacket 41 of the securing sleeve 40.

As can be seen particularly in FIG. 10, the shaft cage 20 has recesses 21 for the resilient mounting of the spring bodies 31 in each of which a spring body 31 is mounted in a clamping manner, whereby the respective spring body 31 is supported in a clamping manner on the shaft cage with its clamping contour K against a mating contour (inner edge 24).

A respective first set of four guide elements 30, each of which is arranged so as to be offset from one another by 90° in the circumferential direction, specifically in the lower assembly region M1 of the shaft cage 20, is mounted in the receptacles 21 provided there. Likewise, a second set of four guide elements 30 is mounted in the upper assembly region M1 of the shaft cage 20 in the receptacles 21 provided there.

Four lugs N which are attached to the corners protrude from the bearing portion 35 of the respective spring body 31.

The receptacles or recesses 21 are at least partially embodied as openings, enabling the resilient support arms 32 to extend through the openings at least with a portion 32a (in this regard, see the exemplar in FIG. 10).

Advantageous aspects of example embodiments of the present invention are achieved by the combination of features according to the claims.

According to example embodiments of the present invention, a spring strut for a pendulating chair is proposed which comprises a central cylindrical middle shaft which is mounted in an axially displaceable manner on a plurality of guide elements in a shaft cage which can be received in a cylindrical securing sleeve having an innerjacket, wherein the guide elements each have a spring body on which resilient support arms, each with a clamping contour, are provided, and a caster which is mounted rotatably on a shaft, wherein the shaft cage, for resilient mounting of the spring bodies, forms respective recesses (openings) in each of which a spring body is mounted with clamping, and the respective spring body bears with clamping with its clamping contour on a mating contour on the shaft cage.

The specific design of the spring bodies ensures that the casters are supported under tension against the center shaft in their clamping state. The length, shape, and form of the spring arm is selected such that the desired freedom of play is achieved at a certain spring force.

An advantageous design of the example embodiments makes a provision that the clamping contour is embodied as a holding lug which protrudes from the support arm and preferably forms a contact surface or an undercut on one side. Advantageously, the mating contours on the shaft cage which are provided for the purpose of clamping a support arm are each instantiated by an edge at the respective recess, particularly an edge that points inward toward the center, namely on the edge that forms the transition from the inner surface of the shaft cage to the side surface of the respective recess.

It is also advantageous if the recesses for receiving a spring body each have a substantially rectangular central opening cross section which is adjoined by two laterally diametrically opposed and circumferentially extending recess regions for receiving the support arms, which recess regions in particular have a lower height when viewed in the axial direction in comparison to the height in the region of the central opening cross section.

In an advantageous embodiment of the invention, a provision is made that the central shaft has a portion at one end for attachment to or in a pendulum joint.

In a likewise advantageous embodiment of the invention, a provision is made that a first set of guide elements (e.g., four guide elements) is mounted in recesses that are arranged in the circumferential direction in a first (lower) assembly region (lower assembly level) of the shaft cage.

Spaced apart therefrom in the axial direction is a second set of guide elements (e.g., also four guide elements) which is mounted in an upper assembly region in additional recesses that are arranged in the circumferential direction. This results in two radially circumferential bearing portions for the center shaft which are spaced apart from one another in the axial direction and thus contribute to a play-free and low-noise supporting of the center shaft.

Example embodiments of the present disclosure provide a technical solution that is also advantageous in which three or four guide elements are respectively arranged in the circumferential direction on a common mounting plane of the shaft cage, preferably at positions with an angular interval of 120° or 90°. For example, if there are four guide elements, these can be distributed in the circumferential direction at the 3 o'clock, 6 o'clock, 9 o'clock, and 12 o'clock positions.

In another advantageous embodiment of the invention, a provision is therefore made that the recesses have openings through which the resilient support arms extend with at least one portion.

It is also preferred if two support arms on diametrically opposed sides of the spring body are each integrally connected to the spring body via an arc portion and these extend radially outward when the spring body is in the assembled state.

It is also advantageous if the bearing portion of the spring body is embodied as a partially cylindrical surface, preferably with a radius of curvature that corresponds to the radius of the cylindrical inner jacket of the securing sleeve and the spring bodies in the assembled state are arranged completely within the envelope of the shaft cage spanned by the outer jacket.

It is also advantageous if, in addition to the respective recesses, bearing blocks are provided on the shaft cage as counter-bearings for the resilient support arms in such a way that the support arms are resiliently supported against the same with a lateral bearing surface that faces away from the respective spring body when the guide elements are inserted through the securing sleeve into their assembly position. The support arms are compressed from their preassembly position. The desired spring force can be achieved on the basis of the spring geometry, material, and spring properties of the spring arms.

Another aspect of example embodiments of the present invention relates to a pendulating chair with a seat part and a foot part on which a pendulum joint is arranged and a spring strut which is equipped with a coil spring and designed with the aforedescribed features, the spring strut being attached at one end to the pendulum joint.

In addition to the spring strut, another aspect of the present invention relates to the method for assembling such a spring strut comprising at least the following steps:

• • a. mounting of the plurality of guide elements from the outside through the openings or the recesses of the shaft cage such that the casters of the guide elements are each aligned toward the intended position of the center shaft, and
  • b. clampingly locking-together of the guide elements (30) with their support arms (32) against the mating contour on the shaft cage (20).

The center shaft is preferably then inserted. In particular, by virtue of this clever design of the shaft cage, the guide elements remain in their intended clamping position even without the center shaft.

The invention is not limited in its execution to the abovementioned preferred exemplary embodiments. Rather, a number of variants are conceivable which make use of the illustrated solution even in the form of fundamentally different embodiments.

Claims

1. A spring strut (1) for a pendulating chair (100) comprising a central cylindrical middle shaft (10) which is mounted in an axially displaceable manner on a plurality of guide elements (30) in a shaft cage (20) which can be received in a cylindrical securing sleeve (40) having an inner jacket (41), wherein the guide elements (30) each have a spring body (31) on which resilient support arms (32), each with a clamping contour (K), are provided, and a caster (34) which is mounted rotatably on a shaft (33), wherein the shaft cage (20), for resilient mounting of the spring bodies (31), forms respective recesses (21) in each of which a spring body (31) is mounted with clamping, and the respective spring body (31) bears with clamping with its clamping contour (K) on a mating contour on the shaft cage (20).

2. The spring strut (1) as set forth in claim 1, characterized in that the clamping contour (K) is embodied as a retaining lug (37) projecting from the support arm (32).

3. The spring strut (1) as set forth in claim 1, characterized in that the mating contours on the shaft cage (20) which are provided for the purpose of clamping a support arm (32) are each instantiated by an edge (24) at the respective recess, particularly an edge that points inward toward the center.

4. The spring strut (1) as set forth in claim 1, characterized in that the recesses (21) for receiving a spring body (31) each have a substantially rectangular central opening cross section which is adjoined by two laterally diametrically opposed and circumferentially extending recess regions for receiving the support arms, which recess regions in particular have a lower height when viewed in the axial direction in comparison to the height in the region of the central opening cross section.

5. The spring strut (1) as set forth in claim 1, wherein the central shaft (10) has a portion (11) at one end for attachment to or in a pendulum joint.

6. The spring strut (1) as set forth in claim 1, characterized in that a respective first set of guide elements (30) is clampingly mounted in receptacles (21) that are respectively arranged in the circumferential direction in a first (lower) assembly region (M1) of the shaft cage (20), and a second set of guide elements (30) is clampingly mounted in additional receptacles (21) which are spaced apart axially from the first assembly region (M1) and are respectively arranged in the circumferential direction in a second (upper) assembly region (M2).

7. The spring strut (1) as set forth in claim 1, characterized in that three or four guide elements (30) are respectively arranged in recesses (21) that are arranged in the circumferential direction on a common mounting plane of the shaft cage (20), preferably at positions with an angular interval of 120° or 90°.

8. The spring strut (1) as set forth in claim 1, characterized in that the recesses (21) are embodied as openings and the resilient support arms (32) extend through the openings at least with a portion (32a).

9. The spring strut (1) as set forth in claim 1, characterized in that two support arms (32) on diametrically opposed sides of the spring body (31) are each integrally connected to the same via an arc portion (32b) and are arranged within the envelope of the outer jacket of the shaft cage (20) when the spring body (31) is in the assembled state.

10. A pendulating chair with a seat part and a foot part on which a pendulum joint is arranged and a spring strut (1) which is equipped with a coil spring and designed with the aforedescribed features as set forth in claim 1, the spring strut (1) being attached at one end to the pendulum joint.

11. A method for assembling a spring strut (1) as set forth in claim 1, comprising at least the following steps: a. mounting of the plurality of guide elements (30) from the outside through the openings (21) of the shaft cage (20) such that the casters (34) of the guide elements (30) are each aligned toward the intended position of the center shaft, andb. clampingly locking-together of the guide elements (30) with their support arms (32) against the mating contour on the shaft cage (20).