EP2997856A1 - Chair covering - Google Patents

Abstract

The invention relates to a chair, in particular office chair, with a seat element, a backrest and a support frame on which the seat element and the backrest are arranged. The backrest and / or the seat element are formed by a backrest frame or a seat frame and a surface element (11) spanned on the backrest frame and / or the seat frame. On the surface element (11) a plurality of fastening elements (17) for attachment to the back frame and / or the seat frame are formed.

Description

Field of the invention

The invention relates to a chair according to the preamble of claim 1.

State of the art

The backrest and the seat of chairs are often provided with a textile covering. The fabric may be formed as a coating which is pulled over a clamping frame of the backrest. In another embodiment, the clamping frame is made in two parts and the fabric is clamped between the two frame parts. The covering gives the chair user a pleasant resilient backrest function and adapts to the back of the user, but also has some disadvantages. On the one hand, the installation of the clothing in the clamping frame is relatively expensive, since a circumferential retaining element or a piping, for example a plastic profile, must be fastened to the fabric edge, so that the clothing is reliably held between the frame parts. On the other hand, the fabric quickly soils and is difficult to clean because it is not removable in the other embodiment.

Such Lehnenbespannung shows, for example, the DE 10 2009 036 958 A1 , The fabric is attached to the backrest frame also on cross members to give the backrest cover a shape that is adapted to the back of a user.

In the WO 2010/069411 A1 a seat cushion element is described, which has a sprung surface of a first thermoplastic material. The surface has on opposite sides fastening elements for mounting on a frame. The fastening elements have an overmolded area and are made of a second thermoplastic material which forms a chemical bond with the first thermoplastic material. By providing two different thermoplastic materials, the properties of the plastics can be optimally adapted to the different requirements of the sprung surface and the fastening elements be adjusted. However, the production is complicated and therefore costly.

In the US 3,767,261 is a seat and backrest covering wound, wavy spring wire disclosed. The adjacent spring wire paths touch each other at least once per period. The wave paths are surrounded by a plastic coating. The tracks are held together exclusively by the sheath. The fact that the backrest cover in the untensioned state assumes the shape of a cylinder jacket, it has a good elastic effect when it is clamped in a chair frame. However, the production is complicated, since the wave paths must be arranged exactly when they are coated with plastic. Also, the string loses its suspension when the plastic joint should break between the wire tracks.

In the US 2010/0001572 A1 a backrest is shown to improve seating comfort. On the backrest vertically oriented ribs are formed, which are interrupted by vertical elongated slots. The vertical rows of slots, which are separated from the ribs, are vertically offset from one another. In the middle area, the ribs are larger and therefore stiffer. The backrest is connected to 4 retaining points with a form-fitting backrest frame. The breakpoints are realized in that cylindrical extensions of retaining claws are included. The preparation of these forms is complicated and the breakpoints run the risk of being torn at higher load. The crooked retaining claws also tend to be dirty and are difficult to clean.

In the WO 2009 a chair is described with a frame and a string stretched on the frame. The fabric is attached to the frame with a plurality of separate support members. The holding elements are designed as a first and second latching element, which are locked together with each other in different length positions. In this case, the first locking elements are attached to the chair cover and the second locking elements on the frame. The tension of the clothing can be adjusted by the different locking positions to the needs of the chair user. However, the first and second locking elements must be attached to both stringing and frame. In addition, the Verrastungszähne provide investment points for contamination.

Object of the invention

Object of the present invention is to provide a chair with a fabric, which fabric is cheaper to produce than known fabrics, is quickly connected to the tenter of the chair and also easy to clean.

description

A chair, in particular an office chair comprises a seat element, a backrest and a support frame, on which the seat element and the backrest are arranged. In the subject invention is a chair in which the backrest and / or the seat element are formed by a back frame or a seat frame and a spanned on the back frame and / or the seat frame surface element. These features are well known in the art. On the surface element, a plurality of fasteners for attachment to the back frame and / or the seat frame are formed. The manufacture of the backrest or of the seat element is simplified significantly, since no more piping attached to the surface element, in particular sewn, must be to hold the surface element to the back frame. During production, the time-consuming step of fastening the cedar can be completely dispensed with. Since the surface element is produced by injection molding, its production is particularly fast, since the injection molding process has high cycle rates. It is also not necessary to cut textile surface webs because the surface element leaves the mold with high imaging accuracy.

The object is achieved according to the invention in that the fasteners are made of the full all-round edge. The fastening elements are formed by the fact that a circumferential web, which is formed on the outer edge of the surface element, is reworked. The fasteners are therefore made of a cast with the surface element and accordingly stable. The injection mold for the production of the surface element can be designed simply as a continuous edge is sufficient. The manufacturing costs of the injection mold can therefore be significantly reduced compared to injection molds in which fasteners are poured out. Furthermore, a closed edge is easier to demould than individually shaped fasteners.

The subsequent processing of the full edge can lead to a surface element in which the fastening elements may preferably have different widths. The injection-molded surface element can therefore have different biases at certain points due to the different widths of the fastening elements when it is clamped in the seat frame or the back frame. It is also advantageous that an injection mold can be used for all surface elements, regardless of the width of the fastening elements.

Conveniently, the surface element is integrally formed with the plurality of fasteners. An attachment of fasteners in a time-consuming further production step is therefore not necessary.

In a particularly preferred embodiment, the fastening elements are formed as hooks which are suspended in the fuselage frame and / or in the seat frame. The hooks can be cut out of the surface element, but can also be poured together with the remaining surface element. The hooks are formed as a part of the surface element and therefore can not be detached from the surface element.

It proves to be advantageous if a plurality of passage openings are provided on the backrest frame and / or the seat frame, into which the fastening elements of the surface element latch. An attachment of the sheet material to the back frame can therefore be done very quickly by hooking. Backrest frame and surface element are both preferably produced by injection molding and work together accurately without having to be reworked after removal from the mold. Furthermore, the attaching step of hooking is easy and quick to do.

The fact that the surface element is biased to advantage on the back frame and / or on the seat frame, resulting in a reliable connection between the back frame and surface element. The fasteners are under tension and can not slip out of the back frame. It would be possible to additionally secure the fasteners, for example by screws.

Suitably, the bias causes a width expansion between 3% and 10% and preferably between 5% and 8% of the surface element. This expansion under prestressing is made possible by the elastic thermoplastic polyurethane. In addition, the expansion can be influenced by the shape and size of the passages of the surface element. An expansion in the claimed area causes sufficient bias in a still existing resilient effect of the backrest. The fact that the surface element has not yet reached its yield point under the bias, it can be hung without too much force in the backrest frame. Preferably, the surface element is stretched on the back frame only in the horizontal direction, ie along the width dimension. It is also conceivable, of course, a bias in the vertical direction.

In a particularly preferred embodiment, the dimensions of the width of the stress-free surface element between 3% and 10% and preferably between 5% and 8% smaller than the width dimension of the back frame, whereby the surface element is biased in the horizontal direction on the back frame. The vote of the dimension of the back frame and the dimension of the surface element lead to a defined bias of the surface element.

The advantageous material of the surface element, which is a thermoplastic polyurethane (TPU), is characterized by its good processability by injection molding, its high imaging accuracy, its high stability and its extensibility. Furthermore, TPU is easy to clean and disinfect. The chair according to the invention is therefore very well suited for applications in which high hygienic standards are required. These include, for example, the medical sector and the food-producing sector.

In a particularly preferred embodiment, the surface element with the plurality of fastening elements is a one-piece injection-molded part. As already explained further, at least one production step can be saved with a single part, which comprises surface element and holder.

It proves to be advantageous if the surface element has the shape of a network with network passages and network webs. The net shape allows a flexible, stretchable surface element, which is nevertheless stable. By determining the strength and length of the mesh webs, the extent of elasticity can be influenced.

Conveniently, the carrying capacity of different areas of the clamped surface element by the strength and the length of the web webs and the measure of the bias is adjustable. The selective control of the degrees of hardness makes it possible for the backrest, for example, in the shoulder area, to have a different hardness than in the lordosis area.

In a further preferred embodiment, the passages of the network are polygonal and preferably hexagonal. This results in a honeycomb structure, since the 6 polygons divide webs. At the edges of the surface element, the polygons may also have a different number of corners in order to provide the surface element as full as possible with passages.

In a further preferred embodiment, the fastening elements are made of solid. The fastening elements are formed by the fact that a circumferential web, which is formed on the outer edge of the surface element, is reworked. The fasteners are therefore made of a cast with the surface element and accordingly stable.

Advantageously, the passages at the edge of the surface element have the shape of uniform polygons and have the center of the surface element, at predefined locations, a shape in which at least one diagonal is shorter than the remaining diagonals. The ridges of the polygons, which have a shorter diagonal, are easier to expand. Thus, the extensibility of the surface element can be increased or reduced at predefined points by the shape of the polygons or their webs.

Conveniently, the shorter diagonals of the passages are oriented in the clamping direction of the surface element. This orientation of the diagonals allows the surface element to expand more easily in one direction, thereby facilitating clamping onto the back frame.

In a further preferred embodiment, the hooks facing the back frame or the seat frame and close with the surface element an angle between 20 degrees and 80 degrees, preferably between 30 degrees and 70 degrees, and more preferably between 40 degrees and 60 degrees. The provision of an acute angle allows the hook to grip the back frame like a claw.

In a further preferred embodiment, the backrest frame or the seat frame is in one piece. This embodiment has the advantage that it is simple in construction, since the surface element only has to be connected to the backrest frame, or has to be hooked into it. So that the fastening elements do not unintentionally detach from the backrest frame, securing elements can be provided. Conceivable, for example, projections, which have a kind of barbs and prevent the fasteners from loosening.

In a further preferred embodiment, the backrest frame or the seat frame comprises a clamping frame for clamping the planar element and a holding frame, with which the clamping frame is connected. This embodiment has the advantage that the fastening elements are prevented from being released from the holding frame by the clamping frame. The combination of support frame and clamping frame increase the stability of the Lehenrahmens or the seat frame. Holding frame and clamping frame can be connected with positive locking, for example, screw or clamp connections.

It is preferred if the TPU has a tensile strength between 10 and 25 MPa (megapascals), preferably between 15 and 20 MPa and particularly preferably between 17 and 19 MPa. This tensile strength ensures that the panel can support the weight of a user of the chair and does not break. However, such a tensile strength allows a certain extensibility, so that the surface element can be clamped in the backrest frame.

Figur 1:

ein Flächenelement zur Bespannung einer Rückenlehne eines Stuhls in einer Frontansicht;

Figur 2:

das Flächenelement in einer Seitenansicht;

Figur 3:

das Flächenelement in einer axonometrischen Ansicht;

Figur 4:

einen Spannrahmen in Frontansicht;

Figur 5:

den Spannrahmen in einer Seitenansicht;

Figur 6:

den Spannrahmen in einer axonometrischen Ansicht;

Figur 7:

einen Halterahmen in Frontansicht;

Figur 8:

den Halterahmen in einer Seitenansicht und

Figur 9:

den Halterahmen in einer axonometrischen Ansicht.

Further advantages and features will become apparent from the following description of an embodiment of the invention with reference to the schematic representations. It shows in not to scale representation:

FIG. 1:

a surface element for covering a backrest of a chair in a front view;

FIG. 2:

the surface element in a side view;

FIG. 3:

the surface element in an axonometric view;

FIG. 4:

a clamping frame in front view;

FIG. 5:

the clamping frame in a side view;

FIG. 6:

the stenter in an axonometric view;

FIG. 7:

a holding frame in front view;

FIG. 8:

the holding frame in a side view and

FIG. 9:

the holding frame in an axonometric view.

The invention relates to a chair, in particular an office chair, which conventionally comprises a seat element and a backrest, which are arranged on a support frame. The support frame can be equipped with a roller frame.

The backrest is formed by a backrest frame and a surface element 11 clamped on the backrest frame. The back frame is according to the embodiment of FIGS. 4 to 9 executed in two parts. It comprises a clamping frame 13 and a holding frame 15 which is connected to the clamping frame 13. The surface element 11 is clamped on the clamping frame 13 by being hooked to this. Then, the clamping frame 13 is screwed to the holding frame 15, so that the surface element 13 from the clamping frame 13 can not unhook.

The surface element 11 is injection-molded from a thermoplastic polyurethane, preferably a thermoplastic polyester-polyurethane. This material is characterized by its good processability by injection molding, its high imaging accuracy, its high stability and its ductility. The thermoplastic polyester-polyurethane has a tensile strength of 18 MPa (megapascals). In injection molding fasteners are mitausgeformt in the form of a running in the direction of the clamping frame 13 at an acute angle leg in one piece. The leg can be formed around the edge of the surface element 11. The surface element 11 is thus made with the leg of a cast. From the leg a plurality of hooks 17 are formed by these are formed from the solid. ie From the leg gaps 19 are cut at uniform intervals, whereby the remaining leg parts transform into hooks 17. The gaps 19 may also have different distances, creating hooks 17 with different widths. This is particularly advantageous if the surface element at different points of the clamping frame 13 to have different biases. It is also conceivable to mold the hooks already during injection molding. However, this means a complex mold, since for each hook 17 a negative impression must be provided in the injection mold.

The surface element 11 has the shape of a network with a plurality of polygonal openings 21 and net passages and the webs 25 separating the openings. The openings 21 vary in their shape, depending on which point of the surface element they are provided. If the surface element 11 has an improved extensibility at one point, openings 21 with an enlarged surface are provided at this point, which may additionally have diagonals of different lengths. If the openings 21 are positioned with their shortened diagonal in the clamping direction, the extensibility of the surface element in the clamping direction is improved. The shape of the openings 21 makes it possible to improve or reduce the extensibility of the surface element at predefined locations. The strength and length of the mesh webs 25 also contributes to the extensibility and load-bearing capacity of the planar element 11.

The surface element 11 is clamped on the clamping frame 13. The hooks 17 are pulled over the edge 23 of the clamping frame 13 and hooked on this. It is also possible that a plurality of through openings are provided on the clamping frame 13, in which the hooks 17 of the surface element 11 engage. The surface element 11 is biased by the latching of the hook 17 on the clamping frame. Preferably, the relaxed surface element on the clamping frame 13 is biased or expanded by 5 to 8% in the longitudinal and transverse directions. Since the thermoplastic polyester-polyurethane is elastic, results in the backrest a slightly resilient effect similar to a trampoline.

The hooks 17 close with the plane of the surface element 11 at an acute angle, which is preferably about 60 degrees. Due to the acute angle, the surface element 11 is reliably hooked to the clamping frame. Thus, the hooks 17 can not bend and the backrest has improved stability, the clamping frame 13th received in the holding frame 15. The outer edge of the clamping frame 13 and the inner edge of the holding frame are formed such that they fit flush with each other. This interaction of the two frames 13, 15 prevents the hooks 17 from bending and releasing from the clamping frame 13, since the hooks 17 abut on the holding frame 15. The frames are screwed together or hooked together by means of clips. It is also conceivable that the backrest frame is in one piece.

Legend:

11

surface element

13

tenter

15

holding frame

17

hook

19

interspaces

21

Polygonal openings, grids

23

Edge of the clamping frame

25

network bridges

Claims (15)

Chair, especially office chair, with a seat element, - a backrest, - A support frame on which the seat element and the backrest are arranged, wherein
the backrest and / or the seat element are formed by a backrest frame or a seat frame and a surface element (11) spanned on the backrest frame and / or the seat frame, and - A plurality of fastening elements (17) for attachment to the back frame and / or the seat frame, which are formed on the edge of the surface element (11) and form a one-piece injection-molded unit with the surface element,
characterized,
that the fastening elements (17) are made of the full all-round edge. Chair according to claim 1, characterized in that the fastening elements (17) have different widths. Chair according to one of the preceding claims, characterized in that the fastening elements are formed as hooks (17) which are suspended in the fuselage frame and / or in the seat frame. Chair according to one of the preceding claims, characterized in that on the back frame and / or the seat frame, a plurality of through holes are provided into which the fastening elements of the surface element (11) engage. Chair according to one of the preceding claims, characterized in that the surface element (11) is prestressed on the back frame and / or on the seat frame. Chair according to claim 5, characterized in that the bias causes a width extension between 3% and 10% and preferably between 5% and 8% of the surface element (11). Chair according to one of the preceding claims, characterized in that the dimensions of the width of the tension-free surface element (11) between 3% and 10% and preferably between 5% and 8% are smaller than the width dimension of the back frame, whereby the surface element (11) in horizontal direction is biased to the back frame. Chair according to one of the preceding claims, characterized in that the surface element (11) consists of a thermoplastic polyurethane (TPU). Chair according to one of the preceding claims, characterized in that the surface element (11) with the plurality of fastening elements (17) is a one-piece injection-molded part. Chair according to one of the preceding claims, characterized in that the surface element (11) has the shape of a network with net passages (21) and web webs (25). Chair according to claim 10, characterized in that the carrying capacity of different areas of the clamped surface element (11) by the thickness and the length of the web webs (25) and the measure of the bias is adjustable. Chair according to one of claims 3 to 11, characterized in that the hooks (17) facing the back frame or the seat frame and with the surface element (11) an angle between 20 degrees and 80 degrees, preferably between 30 degrees and 70 degrees and more preferably between 40 degrees and 60 degrees. Chair according to one of the preceding claims, characterized in that the backrest frame or the seat frame is in one piece. Chair according to one of claims 1 to 12, characterized in that the backrest frame or the seat frame a clamping frame (13) for clamping the Surface element (11) and a (15) holding frame to which the clamping frame is connected comprises. Chair according to one of the preceding claims, characterized in that the TPU has a tensile strength between 10 and 25 MPa, preferably between 15 and 20 MPa and more preferably between 17 and 19 MPa.

Images