Seating furniture

Abstract

Seating furniture (14), in particular a chair, with a plane of symmetry (15) and with a seat surface divided into a rear seat surface part (2) and a front seat surface part (5) pivotable about this part about a seat division axis (8), with a backrest (3) connected to the rear seat surface part (2), and with two kinematics (6, 7) arranged on a base (1), each defining a central point (Z1, Z2), wherein the rear kinematics (6) connects the rear seat surface part (2) and the front kinematics (7) connects the front seat surface part (5) to the base (1) spherically about the associated central point (Z1, Z2), characterized in that the two central points (Z1, Z2) lie in the plane of symmetry (15) and above the seat surface parts (2, 5), and that the front kinematics (7) connects the front seat surface part (5) to the base (1) spherically about the associated central point (Z1, Z2). a front pivot axis (10) that is pivotably connected to the seat division axis (8).

Description

[0001] The invention relates to a piece of seating furniture, in particular a chair, in which the seat and the backrest are pivotable about a horizontal transverse axis, according to the preamble of claim 1 and WO 2012 / 123 102 A1 of the applicant.

[0002] This publication describes a pivoting mechanism consisting of two kinematic units mounted on a common base. Each kinematic unit has a base arm that can rotate about the base, an end arm that can pivot about the base arm, and the object to be pivoted, which can pivot about the end arm. These three axes—base axis, intermediate axis, and end axis—intersect at a central point. Since two such kinematic units are provided and the two central points they define are spaced apart, the end object can rotate about the virtual axis between the two central points. This device was used in a piece of seating furniture called Maniola, where the two central points define the hypothetical or virtual transverse axis about which the seat and the backrest, which is formed integrally with it, can pivot.

[0003] From the applicant's DE 10 2018 114 207 B3, it is known to equip a piece of seating furniture with only such a kinematic mechanism, such that the seat forming the end object and the spring-mounted backrest move around this central point as if around a ball joint, the extent of the pivoting range being achieved by a corresponding, additional lever and joint structure. A disadvantage of this solution, similar to the first-mentioned solution, is that when the seating furniture tilts backward, the front edge of the seat surface lifts up considerably, which leads to constriction of the blood vessels in the front of the user's thigh and is therefore uncomfortable during prolonged sitting and is not permitted under many standards.

[0004] In the specific application without lateral swiveling, in the above-mentioned so-called Maniola chair, this lifting is desired and deliberately brought about to achieve a very far back resting position, which is almost equivalent to lying down, and the constriction is prevented by an extendable footrest.

[0005] From EP 3 476 254 A1 of the applicant it is also known to divide the seat surface of a seat which can be tilted about a horizontal transverse axis and to ensure by means of appropriate kinematics that when the backrest and thus also the rear part of the seat surface is tilted back, the front part of the seat surface tilts downwards, so that the constriction of the thigh is avoided.

[0006] Further state of the art is shown in DE 10 2015 104 400 A1, DE 10 2012 212 121 A1 and DE 10 2010 018 802 A1.

[0007] These types of seating furniture, however, offer no possibility of lateral movement, which is understood as movement around a rotational axis lying in the plane of symmetry and essentially horizontal. Such lateral swiveling is medically indicated because it stimulates the constant activation of various muscle groups that otherwise relax while sitting, and because in various applications, such as video games or similar activities, such lateral movement is also desired by the user.

[0008] The object of the invention is therefore to provide a piece of seating furniture that can be pivoted about a horizontal transverse axis, wherein, in the reclined position, the front edge of the seat surface is at least not noticeably raised, and which additionally allows a transverse pivoting about a preferably substantially horizontal longitudinal axis. As in the aforementioned previously known embodiments, the pivot axes should be clearly located above the seat surface and may, but need not, intersect each other.

[0009] These objectives are achieved according to the invention by the features specified in the characterizing part of claim 1. In other words, two of the aforementioned kinematics, a front and a rear one, are used. These are arranged such that both central points lie in the plane of symmetry of the seating furniture, thus defining a longitudinal axis, the central axis. The angle this axis takes with respect to the horizontal depends on the kinematic properties desired by the developer and the area of ​​application, and is freely selectable within a wide range. Significant deviations from the horizontal, even greater than ±45°, are quite useful, for example, in seating furniture for video game users where spatial movements are essential, or in seating furniture used as training equipment.

[0010] The seating furniture is pivoted around this virtual central axis, so the plane of symmetry necessarily follows this pivoting motion. Therefore, when the invention is described as having a vertical plane of symmetry and various horizontal axes, this always refers to the configuration of the seating furniture in a position without pivoting around the central axis. This configuration was chosen for better representation in the drawing and easier verbal explanation of the figures.

[0011] The pivoting of the rear seat section about the transverse axis, which always passes through the rear central point and is normal to the possibly rotated plane of symmetry, is achieved by providing a split seat, wherein the rear part of this split seat is connected to the rear kinematics and thus performs a spherical movement about the rear central point; this rear part of the seat is pivotably connected to a front part of the seat about a seat division axis, which runs horizontally and in the transverse direction, thus normal to the plane of symmetry of the seating furniture, and the front part of the seat is connected to its associated front kinematics by a joint that allows movement at least about an axis parallel to the seat division axis.

[0012] When the seat is reclined, the front edge of the rear seat section moves upwards, as its central point lies above the seat surface. This causes the front part of the seat to pivot around its central point and the seat's dividing axis in a direction that moves the free front edge of the front seat section downwards relative to the rear seat section. Simultaneously, due to the change in the angular position between the two seat sections, at least one of them undergoes a minimal rotation around its central point. The distribution of this minimal rotation between the two kinematic components depends on the forces or moments acting upon it.

[0013] Regarding the concept of the axis of rotation between the two seat sections, the seat division axis, it should be noted that this can be designed in a variety of ways. It can range from a simple axis between the two parts to the formation of an elastic intermediate section (virtual axis) running transversely to the seat surface, or something similar, in which the bending occurs primarily due to the elastic properties of the material used, possibly in conjunction with different cross-sectional shapes or chamber configurations, etc. This means that the axis is no longer fixed to a certain extent with respect to one or both parts. In principle, anything is possible as long as it allows pivoting around a horizontal transverse axis, the seat division axis.

[0014] A similar principle applies to the connection of the front seat section to its corresponding end arm of the kinematic mechanism; here, as will be shown below, an intermediate lever with appropriate pivot joints can be used. Another possibility, which can be designed to be very space-saving, is to provide a universal joint. This corresponds to a design of the intermediate lever with zero length. In this case, the orientation of the axes in space is preferably not perpendicular to each other, since one of the predetermined axes of the end arm runs obliquely in space, and the other must, just as necessarily, run parallel to the seat division axis.

[0015] A ball joint can also be used, in which the spherical mobility inherent to the ball joint, insofar as it deviates from rotation about a horizontal transverse axis parallel to the seat division axis, is prevented by the overall kinematics of the seating furniture; this must also be provided for in the case of a cardan joint.

[0016] Depending on the extent of the intended pivoting movement, it may also be possible here to provide an elastically deformable connection that allows the relative movement.

[0017] As an aside, it should be noted that such elastic connections have conquered areas of application in recent years where the paths, angles, and loads are incomparably greater than in seating furniture; examples include wagon gangways of rail vehicles and the mounting of wagon bodies of rail vehicles on their bogies.

[0018] Regarding the connection between the rear part of the seat and the backrest, it should be noted that this can either be a single piece and relatively rigid, as in the Maniola design; that various adjustments and spring-loaded connections can also be provided, as have long been known, for example, in office chairs; and that movable connections can also be fitted, in which the angle between these two elements changes depending on the angle of inclination and the forces exerted by the user. Such a "dynamic" connection is known, for example, from WO 2016 / 042 127 A1 of the applicant.

[0019] Whether armrests are provided or not, and how they are designed if necessary, is not causally related to the invention and can easily be decided and interpreted by a person skilled in the art with knowledge of it.

[0020] The invention is explained in more detail below with reference to the drawing. The drawing(s) show: the Fig. 1a and Fig. 1b a seat according to the invention in side view, in resting position and swivelled, the Fig. 2a to 2c in front view, in resting state and swiveled, the Fig. 3. A bottom view of the seating furniture. Fig. 1, the Fig. 4 an embodiment of a kinematic device usable according to the invention, hereinafter referred to as kinematics, and the Fig. 5a and Fig. 5b schematically shows the positions of the two seat surfaces in upright and tilted positions.

[0021] The Fig. Figure 1 shows the upper part of a seating unit 14, for example an office chair or a seating unit for use in a video game or the like. A base 1 is shown, which belongs either to a chassis or a support frame, as is known from the prior art in numerous embodiments, optionally movable, and / or rotatable about a vertical axis and / or height-adjustable.

[0022] Two three-axis kinematic mechanisms, described in more detail below, are attached to base 1. These kinematic mechanisms are made of Fig. 3 clearly visible in bottom view and in Fig. Figure 4 shows details. In the illustrated embodiment, the base 1 is provided with two fixed arms. A base arm is rotatably attached to each fixed arm about an axis A1, and the end arm is rotatably attached to the base arm about an axis A2. The end arm is rotatably connected to the associated seat surface section about an axis A3.

[0023] Depending on the embodiment, instead of the quasi-radial, central design and connection of the fixed arms to the base 1, a plate-shaped or disc-shaped sub-base can also be provided, on which the two base arms are rotatably mounted. With knowledge of the invention, the field of application, and the available space, it is easy for a person skilled in the art to make a selection or design in this regard.

[0024] These two kinematics, which together are referred to as rear kinematics 6 and front kinematics 7, thereby merely indicating their arrangement with respect to the rear and front seat surface parts 2 and 5 respectively, each have a central point which is located in Fig. 1 is specified with Z1 and Z2. The corresponding axes A1 (base axis), A2 (intermediate axis) and A3 (end axis) intersect at these central points.

[0025] As seen from both the side view of the Fig. 1 as well as from the front view of the Fig. As can be seen from 2, in the illustrated embodiment the two central points Z1, Z2 are located at the same height, so that the central pivot axis 11 connecting them ( Fig. 1) runs horizontally and in the plane of symmetry of the seating furniture. The mobility of the seating furniture 14 about this central pivot axis 11, the lateral pivoting, is visible from the front view of the Fig. 2a-c, which show the three different layers, are clearly visible.

[0026] Regarding the term "plane of symmetry," it should be further explained that, in a base design as in the illustrated embodiment, typical for an office chair, this encompasses the vertical axis of rotation of this base 1 and divides the seat and backrest sections into symmetrical left and right halves (fictitious). Parts of the kinematics (such as kinematics 6 and 7 in the illustrated embodiment, as seen in the underside view of the Fig. 3) and any mechanisms for height adjustment etc. run asymmetrically to this plane of symmetry, this does not detract from their designation and meaning.

[0027] The side view of the Fig. 1a and Fig. Figure 1b shows the seat 14 in an upright position and in a backward-tilted configuration, also called the resting position. As can be seen, when the backrest 3 and thus the rear seat section 2 are reclined, the front seat section 5 is moved along the seat division axis 8 ( Fig. 3) raised so that its change in angle relative to the rear seat section 2 is in the opposite direction to the rotation of the rear seat section, causing it to be lowered with its free end relative to the rear seat section.

[0028] This relative movement, and thus the lowering of the front seat surface section 5 relative to the rear seat surface section 2, is shown in the diagram reduced to the diagram. Fig. 5a and Fig. 5b particularly clear: The Fig. Figure 5a depicts the upright position of the seat, with only the two seat sections 2 and 5 shown schematically as lines. Neither the backrest nor the kinematics are shown, but the two central points Z1 and Z2 are. The rear seat section 2 is connected to its kinematics in such a way that it pivots around a transverse axis about Z1, such that its angular position always remains unchanged with respect to the fictitious connection F1, indicated by the (also fictitious) "stiffening triangle" 12. The front seat section 5 is pivotally connected at its rear to the front of the rear seat section 2 via the seat division axis 8 and is suspended about the front pivot axis 10, which is parallel to this axis, allowing it to rotate relative to the fictitious connection F2 to the corresponding central point Z2, but always maintaining a constant distance from Z2. This pivoting mechanism is, for example, as shown in Fig. 4 is listed, ensured by the lever 9.

[0029] In the Fig. 5a,b also shows a space-fixed (or fixed with respect to the base and thus the central points Z1 and Z2) horizontal 13, with respect to this horizontal the vertical position of the front edge of the front seat surface part 5 hardly changes, that it is folded downwards relative to the rear seat surface part 2 when the backward tilted rest position is assumed, is shown by the angle of the two parts around the seat division axis 8 in direct comparison.

[0030] As mentioned, this representation is purely schematic and serves to illustrate the mobility of the individual components. A person skilled in the art, with knowledge of the invention and the field of application, can appropriately select the position of the (fictitious) connection points of the seat surface parts to the fictitious connections F1, F2, just as they can also determine the height of the central points above the seat surface parts and, in connection therewith, the position (angle relative to the horizontal) of the central pivot axis 11.

[0031] Regarding the angles and distances specified in the description and requirements, it should be noted that these refer to the seating furniture as it rests on a level surface.

[0032] Levers, stops, guides, cams, etc., which serve to limit the pivoting movements, are not essential to the invention itself and can easily be provided by a person skilled in the art with knowledge of the invention; some examples can be found in the literature cited at the beginning. These elements, and also any springs that may be provided to force the furniture into a basic position (which need not be the resting or upright position), are therefore not shown in the drawing and not explained in the description.

[0033] For supplementary purposes only, the following will be based on the Fig.5 Some dimensions that have been found to be useful in the design of an office chair according to the invention are given below: The distance along the notional connection F1, F2 from the respective central point Z1, Z2 to the associated seat surface section 2, 5 (abutting at a normal foot point in the case of the rear section, leading to the front pivot axis 10 in the case of the front section) with normal thickness and normal softness of the upholstery can be between 350 mm and 450 mm; the distance between the front pivot axis 10 and the seat division axis 8 can be between 120 mm and 150 mm; the distance between the two central points can be between 230 mm and 280 mm; the distance from the foot point of the notional connection F1 to the attachment of the backrest can be between 80 mm and 150 mm. These are only rough guidelines that can be easily adjusted by a person skilled in the art with knowledge of the invention and the field of application. Reference is also made to the criteria and information explained in the aforementioned prior art.

[0034] The terms seat surface part, backrest, armrest are to be understood in the description of the functioning of the invention without conventional supports, covers, padding, etc., even if these are partly indicated in the figures. Reference symbol list: 1 Base 2 rear seat section 3 Backrest 4 Armrest 5 front seat surface section 6 rear kinematics 7 anterior kinematics 8 seat split axis 9 levers 10 front pivot axis 11 Central pivot axis 12 Stiffening triangle 13 Horizontal 14 pieces of seating furniture 15. Plane of symmetry 16 (lateral) swivel joint A1, A2, A3 Axes of the kinematics (base axis, intermediate axis and end axis) F1, F2 fictitious connections Z1, Z2 central points

Claims

[1] Seating furniture (14), in particular a chair, with a plane of symmetry (15) and with a seat divided into a rear seat section (2) and a front seat section (5) pivotable about this section about a seat division axis (8), with a backrest (3) connected to the rear seat section (2), and with two kinematics (6, 7) arranged on a base (1), each defining a central point (Z1, Z2), wherein the rear kinematic (6) connects the rear seat section (2) and the front kinematic (7) connects the front seat section (5) to the base (1) in a spherically movable manner about the respective central point (Z1, Z2), characterized by , that the two central points (Z1, Z2) lie in the plane of symmetry (15) and above the seat surface parts (2, 5), and that the front kinematics (7) is pivotably connected to the front seat surface part (5) about a front pivot axis (10) parallel to the seat division axis (8). [2] Seating furniture (14) according to claim 1, characterized by , that the front pivot axis (10) is formed on a lever (9) which is arranged between the front kinematics (7) and the front seat surface part (5). [3] Seating furniture (14) according to claim 1, characterized by , that the front pivot axis (10) is designed as a spherical bearing, for example as a ball joint. [4] Seating furniture (14) according to claim 1, characterized by , that the front pivot axis (10) is designed as a cardan joint with skew axes. [5] Seating furniture (14) according to claim 1, characterized by , that the front pivot axis (10) is formed by an elastic connection made of plastic between the front kinematics (7) and the front seat surface part (5). [6] Seating furniture (14) according to any one of claims 1 to 5, characterized by, that a central pivot axis (11) defined by the two central points (Z1, Z2) assumes an angle of less than 45°, preferably less than 15° and particularly preferably less than 5° with respect to the horizontal (13). [7] Seating furniture (14) according to any of the preceding claims, characterized by , that the seat division axis (8) is formed by a hinge. [8] Seating furniture (14) according to any one of claims 1 to 6, characterized by , that the seat division axis (8) is formed by two lateral pivot joints (16). [9] Seating furniture (14) according to any one of claims 1 to 6, characterized by , that the seat division axis (8) is formed by an elastic connection made of plastic between the front seat surface part (5) and the rear seat surface part (2). [10] Seating furniture (14) according to any of the preceding claims, characterized by , that the rear seat surface part (2) is formed in one piece with the backrest (3). [11] Seating furniture (14) according to any one of claims 1 to 9, characterized by , that the rear seat surface part (2) is spring-connected to the backrest (3). [12] Seating furniture (14) according to any of the preceding claims, characterized by , that the base (1) is mounted or designed on a support frame which may be movable, and that the base (1) is preferably mounted so as to be rotatable and / or height-adjustable about a vertical axis with respect to the support frame. [13] Seating furniture (14) according to any of the preceding claims, characterized by , that at least one of the kinematics (6, 7) has a base arm which is rotatable about the base (1) about a base axis (A1) and an end arm which is pivotable about the base arm about an intermediate axis (A2), that the rear seat surface part (2) is pivotable about the end arm about an end axis (A3), and that the three axes (A1, A2, A3) intersect each other at one of the central points (Z1, Z2). [14] Seating furniture (14) according to any of the preceding claims, characterized by , that the extent of the pivoting movement about the seat division axis (8) and the front pivot axis (10) is limited by cams and pins, one of the two elements being fixedly connected to the base (1) and the other being fixedly connected to the rear seat surface part (2). [15] Seating furniture (14) according to any one of claims 1 to 13, characterized by , that the extent of the pivoting movement about the seat division axis (8) and the front pivot axis (10) is limited by a lever and joint structure, wherein one end of the lever and joint structure is articulated to the base (1) and the other end to the rear seat surface part (2).

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