1. Field of the Invention
The invention relates to a seat arrangement for sitting furniture. The seat arrangement comprises a seat member and a support arranged at the underside of the seat member and comprising an elastic body for enabling a tilting movement of the seat member about a pivot point located in a central area of the seat member.
2. Description of the Related Art
Seat arrangements which make possible a tilting movement of the seat member about a pivot point centrally arranged on the seat member area are known in various embodiments. The basic principle always resides in that a tilting support is arranged at the underside of the seat member and comprises an elastic body. This elastic body counteracts the tilting movement with a matching restoring force.
A disadvantage of these known tilting devices is the generally relatively complex configuration.
It is an object of the present invention to provide a technically simple seating arrangement for sitting furniture.
In accordance with the present invention, this is achieved in that the elastic body is arranged at the central middle of the seat member, in that the upper side as well as at the underside of the elastic body are fixedly connected to a rigid plate, respectively, and that the top plate is correlated with the seat member and the bottom plate is correlated with the underframe of the sitting furniture.
The basic configuration of the seat arrangement according to the present invention for a piece of sitting furniture comprises a central elastic body which is embedded in a sandwich arrangement between two rigid plates, wherein these two plates are fixedly connected with the elastic body. The elastic body can be particularly made of rubber but also of an elastic plastic material. This provides a technically very simple seat articulation wherein the seat member surface (sitting surface) can be tilted to all sides; this makes possible a dynamic and back-strengthening sitting position. The seat articulation can be mounted in a simple way on different sitting furniture, particularly, chairs (office chairs, stools etc.) without the configuration or the design of these chairs having to be changed. Moreover, the tilting articulation according to the invention is a very inexpensive alternative for movable chairs.
According to a first particular embodiment of the invention, the elastic body is a hollow body. The mantle surface of the hollow body is thus compressed upon tilting of the seat member in the corresponding direction.
According to a further development of this embodiment, the hollow body is a cylindrical body or a barrel body. A characteristic of this hollow body is that it has an outer mantle surface and has a penetration or hollow interior. A barrel body is to be understood as a body whose peripheral mantle surface is either bulged convexly outwardly or constricted concavely inwardly.
According to another development of this embodiment, the cross-section of the cylindrical body or of the barrel body can be a circle or an oval. Inasmuch as the cross-section is a circle, the tilting movement is identical in any radial direction because the same force is always required. For an oval cross-section, on the other hand, the tilting movement is not uniform because, depending on the direction, different forces are required for compressing the hollow body. Accordingly, the tilting characteristic can be affected with regard to the tilting direction. This directional tilting characteristic can be achieved also for a circular hollow body in that the material distribution of the mantle is different about the periphery, for example, in that the mantle has a reduced thickness at certain locations or in that the mantle is provided with hollow spaces at certain locations. Of course, an oval hollow body can also have such different material distributions about its periphery.
According to a further development of the embodiment, the mantle surface of the cylindrical body or of the barrel body is of a contiguous configuration. This means that the entire mantle surface of the body is closed about the periphery.
As an alternative, the hollow body can be comprised of individual elements or mantle sections arranged at several locations on an imaginary ring or annular contour which have between then an intermediate spacing. The number of the individual elements can be selected as desired. However, at least three such elements should be provided.
In a further development of the embodiment, the top and bottom plates have cutouts matching the penetration or hollow interior of the hollow body. This has the advantage that the attachment of the hollow body or annular body on the two plates is simplified in that, for example, vulcanization tools can engage the central opening of the hollow body. Moreover, as a result of the penetrations access to the underside of the seat member as well as to the upper side of the under frame is possible.
As an alternative to the hollow body, the invention proposes a second embodiment according to which the elastic body is a solid body, i.e., not hollow.
According to one development of this embodiment, the solid body is a cylindrical body or a barrel body wherein, according to a specific configuration, the cross-section of these bodies is a circle or an oval, respectively. The solid configuration of the elastic body requires a relatively high force for compression of the body upon tilting. In this connection, a barrel body is to be understood again as one that has a peripheral mantle surface which is either bulged convexly outwardly or constricted concavely inwardly. The inwardly directed curvature enhances the longevity of the solid body. An oval cross-section ensures again a directional compression characteristic.
Preferred technical possibilities for the attachment of the elastic body on the two plates are a vulcanized connection, an adhesive connection, or screw connection. Preferred is the use of vulcanization technology because it provides an absolutely secure and non-detachable connection between rubber and metal without there being the risk that over the course of time the parts will become detached. Alternatively, the materials can also be glued or bonded to one another. In particular in the case of solid bodies a screw connection between the elastic body and the plates is also conceivable.
In connection with vulcanization it is sufficient to realize vulcanization in the area of the outer circumference of the elastic body. This is particularly feasible when the elastic body is an annular body and can be connected with the circumferential edge of its end face to the corresponding penetration of the plate by vulcanization.
According to a modification of the invention, the seat articulation is provided as a separate unit comprised of the elastic body and the two plates, wherein the top plate is connected to the seat member and the bottom plate is connected to the underframe of the sifting furniture.
In contrast to this, it is suggested according to another modification that no separate top and bottom plates are provided but that the elastic body is directly connected to the seat member and/or directly connected to the underframe of the sifting furniture. This provides a seat articulation with even fewer individual parts.
While the seat articulation or seat arrangement according to the invention can be integrated into conventional sitting furniture, a further embodiment suggests that the seat arrangement is a separate unit. This provides an ergonomic seat cover which is not integrated from the start in the sitting furniture but instead is to be installed later in that the seat arrangement is simply placed like a seat cushion onto the seat surface of the seat. The advantage of this separate seat arrangement is that in a technically simple way retrofitting of existing sitting furniture, initially not provided with a tilting device, is possible. The seat of the conventional sitting furniture which is accordingly retrofitted with the seat arrangement according to the invention thus enables an ergonomic sitting position.
When using the tilting seat arrangement according to the invention, a constant balancing is required and each fine movement must be compensated in the same way as when seated on a large ball; this improves posture and strengthens the back muscles, wherein moreover their interaction is optimized and, as a whole, back pain is eliminated.
The advantage of a modification comprising a protective sleeve between the plates resides in that the user is prevented from pinching his fingers between the two plates when the tilting movement is carried out.
The tilting articulation has been described supra in connection with a seat member of sitting furniture. However, it is also conceivable to provide the tilting articulation of the seat arrangement as a connection between a frame element and a back rest of a seat member. The tilting articulation is configured in analogy to the described seat articulation of the seat member. Basically, the principle of the invention thus resides generally in providing a tilting articulation for sitting furniture and seat arrangements, in particular, for the seat member and/or the back rest.