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EP-4740792-A1 - SEATING FURNITURE WITH SEAT, BACKREST AND PIVOTING DEVICE

EP4740792A1EP 4740792 A1EP4740792 A1EP 4740792A1EP-4740792-A1

Abstract

The invention relates to a seating furniture (1) with a base (2) and a seat surface (4) which can be pivoted about a horizontal transverse axis (26) which lies above the seat surface (4) by means of a pivoting device relative to the base (2) between an upright sitting position and a reclined resting position, and with a backrest (5), in particular an office chair. To improve the seating comfort and reduce the cutting into the underside of the user's thighs when leaning back, it is provided that at least one spring element (15, 24, 27) is present which, when the seat surface (4) pivots towards the rest position, generates a restoring moment on the seat surface (4) in the direction of the upright sitting position.

Inventors

  • EHRENLEITNER, FRANZ

Assignees

  • EB-invent GmbH

Dates

Publication Date
20260513
Application Date
20241108

Claims (11)

  1. Seating furniture (1) with a base (2) and a seat surface (4) which can be pivoted about a horizontal transverse axis (26) located above the seat surface (4) between an upright sitting position and a reclined resting position by means of a pivoting device relative to the base (2), and with a backrest (5), in particular an office chair, characterized by that at least one spring element (15, 24, 27) is present which, when the seat surface (4) pivots towards the rest position, generates a restoring moment on the seat surface (4) in the direction of the upright sitting position.
  2. Seating furniture according to claim 1, characterized in that the backrest (5) is firmly, optionally resiliently, connected to the seat surface (4).
  3. Seating furniture according to claim 1 or 2, characterized in that at least the areas of the leg support of the seat surface (4), viewed from the backrest, end shortly after the ischial tuberosity and optionally a leg support follows forward, which is either articulated with the rear part of the seat surface (4) or is designed without a joint by means of an elastically mounted leg support.
  4. Seating furniture according to one of claims 1 to 3, characterized in that the spring element (15) has or consists of resilient lateral parts of a comb-like designed seat surface (28) which are elastically deformed when leaning back.
  5. Seating furniture according to claim 4, characterized in that the elastic deformation is caused by the downward pressure of the thighs of the user of the seating furniture.
  6. Seating furniture according to one of claims 1 to 3, characterized in that the spring element (24) is provided between the base (2) and the seat surface (4).
  7. Seating furniture according to claim 6, characterized in that the rear end of a counter spring (21) designed as a leaf spring is arranged rotatably on the front of the base (2) about a rear axis (25) which is normal to the plane of symmetry (10), the front end of which is arranged about an intermediate axis (20) which is parallel to the rear axle (25), is rotatably connected to the upper end of a leaf spring (19), the lower end of which is rotatably mounted in a holder (23) fixedly connected to the seat surface (4) about a leaf spring axis (18) which is also parallel to the rear axle (25), wherein at least one torsion spring (24), which may be pre-tensioned, is provided about at least one of the axes (19, 20).
  8. Seating furniture according to claim 6, characterized in that the rear end of a rod is rotatably arranged on the front of the base (2) about a rear axis (25) which is normal to the plane of symmetry (10), the front end of which is rotatably connected about an intermediate axis (20) which is parallel to the rear axis (25) to the upper end of a further rod, the lower end of which is in turn rotatably mounted about an axis also parallel to the rear axis (25) in a holder (23) fixedly connected to the seat surface (4), and that at least one torsion spring (24), optionally pre-tensioned, is provided about at least one of the axes (19, 20).
  9. Seating furniture according to claim 6, characterized in that the rear end of a rod is rotatably arranged on the front of the base (2) about a rear axis (25) which is normal to the plane of symmetry (10), the front end of which is rotatably connected about an intermediate axis (20) which is parallel to the rear axis (25) to the upper end of a further rod, the lower end of which is in turn rotatably mounted about an axis also parallel to the rear axis (25) in a holder (23) fixedly connected to the seat surface (4), and that a compression spring is provided between the axes (18, 20) and/or a tension spring is provided between the axes (20, 25).
  10. Seating furniture according to claim 6, characterized in that an end of a tension spring (27) is attached to the front of the base (2), the other end of which is connected to the front edge of the seat (11) below the seat surface (4).
  11. Seating furniture according to one of claims 1 or 3, characterized in that the backrest (5) is articulated, optionally resilient, connected to the base (2), and that the spring element is provided between the seat surface (4) and the backrest (5).

Description

The invention relates to a seating furniture with a seat surface which is pivotable about a horizontal transverse axis located above the seat surface relative to a base by means of a pivoting device and which has a backrest, in particular an office chair, according to the EP 3 193 670 ( WO 2016/042127 A1 ) or the DE 10 2018 114 207 B3 , and the preamble of claim 1. In the prior art (StdT), furniture with a swivel mechanism exists, such as that mentioned above. EP 3 193 670 are known, as well as specifically seating furniture, such as that from the EP 4 294 237 ( WO 2022/174945 A1 ) and the DE 10 2018 114 207 B3 (all three originating from the applicant) are known. All these applications describe, among other things, a design for the swivel device in which the seat is supported by a three-axis kinematic system with a central point, allowing spherical movement around the central point. The seat is also guided as it rotates around a (virtual) transverse axis passing through the center of the spherical movement. Naturally, any kinematic mechanism capable of pivoting the seat around a horizontal transverse axis located above the seat can be used. These include: EP 1 090 568 B1 , EP 2 381 816 B1 , WO 2012/123102 A1 the applicant, WO 2016/042127 A1 the applicant, in particular Fig. 9 and the associated description, explained in more detail in the WO 2013/029069 A1 the applicant. But the invention can also be combined with completely different kinematic systems, such as those of the DE 199 15 003 A1 , or those of EP 3 476 254 A1 the applicant. A key point here is that the vertical position of the swivel axis is placed in the roughly estimated lower region of the user's thoracic spine, since this allows for a comfortable movement of the pelvis and the subsequent part of the spine, especially when a swivel movement around a so-called longitudinal axis, which lies in the plane of symmetry of the furniture is also possible – something desired in many cases for health and training reasons. Movement during walking is promoted. The user's center of gravity then lies above the pivot axis, possibly above the central point. Some terms: Seat surface: This is movable relative to the base and pivotable at least about one (horizontal) transverse axis. Further pivoting about other axes, up to and including spherical mobility, may be provided. The seat surface can be divided along a horizontal axis into a front part and a rear part, which is then rigidly connected to the backrest, as known from the standard design. In this case, the distance between the backrest and the front end of the rear seat section rigidly connected to the backrest, in the area of the possible articulated or flexible leg rest, is 50 mm to 300 mm. The seat surface may be upholstered; this does not change the invention. Backrest; as stated in the application, it can be rigidly, albeit resiliently, connected to the seat or its rear part. It can also be rigidly, resiliently, or pivotally connected to the base about a horizontal transverse axis, as is known from the standard design. Plane of symmetry: divides the furniture into two parts along a vertical plane, whereby at least the seat and backrest are actually divided into two equal parts that are symmetrical to each other; the remaining components and also the fastening elements on the seat and backrest can easily deviate from this symmetry. Regarding the term "plane of symmetry," it should be noted that this only applies with some caveats, because the individual components and handles of seating furniture, for example, office chairs, are indeed unilateral. Nevertheless, a plane of symmetry exists for the seat and, if present, the backrest and armrests, which runs vertically when the seating furniture is at rest and pivots with the seat. It is this plane that will be considered the plane of symmetry in the following. Virtual axis(s): Since the pivot axis(s) of the seat surface are located above it, they do not consist of bearings, sleeves, or similar components, but are Various kinematic mechanisms known from standard technical literature, such as the aforementioned three-axis kinematic mechanism with a central point, are used. It should be noted that the version with a central region instead of a central point, also known from standard technical literature, can also be used in the present invention. As explained in detail below, the problem is that, after some time, using the aforementioned seating furniture causes the user discomfort when leaning back. Another problem, equally significant in practice, is that when leaning back around the transverse axis, the front edge of the seat is lifted and constricts the user's thighs from below. The main objective of the invention is to provide a solution for at least one of these structurally related problems, preferably both. Since the state of the art will be explained in more detail below using the drawing, the corresponding figures are already listed here. They