GB2255008A - "chair" - Google Patents

Abstract

A chair comprises a back member which is of varying rigidity across its width and/or height due to areas of gradually varied rigidity and strength. These areas may be formed from layers of laminated sheets or alternatively from channels adapted to receive a fluid upon compression of a reservoir of fluid in a seat member.

Description

"Improved Chair" This invention relates to chairs of the type which provide back support, and is particularly, although not exclusively, concerned with the means of providing said support. The invention also relates to a means of reclining a chair.

In the past, chairs providing back or lumbar support have been commonly known and such back support frequently comprises a planar type member mounted on a frame. The members have been made from various materials, including plastics, wood and metal, all of which may provide a respective degree of resilience and flexibility. Furthermore, planar members of this type have been moulded or formed in accordance with the shape of a person's back.

A considerable disadvantage inherent in the lumbar supports provided by chairs of this type is that the flexibility and resilience which they provide is primarily a product of the: materials used and is therefore constant over the entire area of the back support or alternatively directly proportional to the linear distance from a hinge point in the support.

It has also been previously known to provide reclining means in chairs. This has usually been made possible by the provision of a hinge joint between the back member of the chair and the seat member of the chair.

The hinge joint has enabled the back member to recline in relation to the seat member. However, it is realised in the invention that it is often desirable to provide reclining means while maintaining a constant angle between the back member and the seat member.

It is also realised in the invention that certain areas of one's back are appropriately provided with a more rigid support than other areas; these other areas preferably receiving back support that has moulding characteristics to conform to a person's own particular shape.

According to the present invention there is provided a chair comprising a back member for supporting a person's back while sitting, wherein the back member is of varying rigidity across its width and/or height.

Preferably, the back member has areas of gradually variable rigidity and strength to provide greater support in certain areas of the back member.

Preferably, the back member is formed from laminated sheets and a flexible membrane.

Preferably, the sheets are made from a thermo-plastic material.

Preferably, the sheets are impregnated with fibres in localised areas to increase the stiffness and rigidity in those areas.

Preferably, the sheets are moulded with a ribbed or cellular texture, the ribs or cellular texture being adapted to provide increased stiffness and rigidity in localised areas.

Preferably, the ribbed or cellular texture allows cushioning of adjacent sheets and compression of the flexible membrane.

Preferably, the sheets are of varying shape, having cut out areas, so as to provide localised areas of greater stiffness and rigidity than other areas within the back member.

Preferably, the cut out areas of adjacent laminated sheets are dimensioned so as to provide a gradual transition from areas of a high relative rigidity to areas of a high relative flexibility.

Preferably, stiffer or more rigid areas are located towards a lower part of the back member and towards an outer frame of the back member.

Preferably, the back member is provided with a fabric, wherein the fabric is moulded around the exterior of the sheets.

Alternatively, the fabric is bonded around the exterior of the sheets.

Preferably, cushioning means is provided in the back member and located between the fabric material and the sheets.

Preferably, the outer frame is integral with the sheets, wherein the frame is formed by localised stiffening around the perimeter of the sheets.

Preferably, the localised stiffening of the frame is formed from ribs moulded integrally with the sheets.

Alternatively, the back member includes a metal frame.

Preferably, the metal frame is made from an aluminium extrusion.

Preferably, the back member is concave at the lower back area and convex near the mid-back area.

Preferably, the maximum point on the convex profile of the back support is provided with a flexible joint.

Preferably, the back member comprises an upper section and a lower section, wherein the upper section and the lower section are connected by the flexible joint and are adapted to allow rotational movement in relation to each other.

Preferably, the flexible joint includes a spring, wherein the tension of the spring is adjustable.

Preferably, one or more of the sheets or flexible membrane are provided with slots which act as finger springs, so as to provide increased flexibility in localised areas.

Preferably, the flexible membrane includes sprung moulded elements which provide a basic form to the membrane in accordance with the shape of a person's back and limit the degrees of freedom of flexibility of the membrane.

Preferably, the membrane is made from SISEARA (Trade Mark) webbing.

Alternatively, the membrane is made from a rubber material.

Preferably, the membrane provides a pirrelli platform.

Alternatively, the chair may comprise a seat member and a back member, wherein the seat member includes a fluid reservoir, wherein the back member includes channels communicating with the reservoir adapted to receive the fluid upon compression of the reservoir, and wherein the receiving of the fluid in the channels causes the back member to be stiffened in the localised areas of the channels.

Preferably, the channels are located in areas requiring a relatively greater stiffness and rigidity.

Preferably, the channels include non return valves to control the flow of the fluid back into the reservoir.

Preferably, the quantity of stiffness and rigidity in the localised areas of the back member is proportional to the weight of a person sitting on the seat member.

Preferably, the chair may comprise a seat member, a back member and reclining means, wherein the reclining means enables the chair to be reclined while maintaining a constant angle between the seat member and the back member.

Preferably, the seat member is hingeably mounted on a support stand.

Preferably, the reclining means comprises a fixed support lever and a seat frame, wherein the fixed support lever is in fixed relationship with the support stand, wherein the seat frame is in fixed relationship to the seat member, and wherein movement means is provided between the seat frame and the fixed support lever.

Preferably, the movement means includes a spring assisted multi-position wedged assembly, providing a cam action between the lever and the seat frame.

Preferably, the seat frame and the fixed support lever are located inside the seat member and concealed from view.

Preferably, the spring is a gas spring, actuatable externally of the seat member.

Embodiments of the present invention will now be described, by way of example only, in accordance with the accompanying Figures, in which; Fig. 1 is a pictorial view of a chair in accordance with the invention, Figs.-2 and 3 are exploded perspective views of laminated sheets of back members, Fig. 4 is a perspective view of a back member divided into an upper section and a lower section, Fig. 5 is a perspective view of a back member having finger springs for flexibility, Figs. 6 and 7 are perspective views of back members comprising hydraulic stiffening means, and Fig. 8 is a side view of a chair having reclining means in accordance with the invention.

In a first embodiment of the invention, a back member 1 of a chair is made from laminated thermo-plastic sheets 2 and a laminated flexible membrane 3. Any reasonable number of sheets 2 may be laminated together depending on the thickness of each sheet, although the back member 1 is preferably between 3 millimetres and 10 millimetres thick.

The thermo-plastic sheets 2 may have stiffening fibres impregnated to increase their strength. In some embodiments glass fibres may be used, although it is realised in the invention that other suitable high strength fibres may be used to reinforce the plastics material.

The direction of the fibres may differ in respect of each laminated sheet to ensure high strength characteristics in a multiple number of directions.

This is shown in Fig. 2.

The thermo-plastics sheets 2 can also be impregnated with fibres in only localised areas to increase the stiffness and rigidity in those particular areas, while leaving other areas of the back support 1 more flexible and mountable.

In other embodiments, the localised stiffening means may be provided by a ribbed or cellular texture on the surface of each sheet. For example, the sheets may be moulded with a ribbed exterior in localised areas to provide increased stiffness and rigidity in those areas. The ribbed or cellular texture also allows cushioning of adjacent sheets 2 and compression of the flexible membrane 3.

Referring to Fig. 3 the sheets are provided with cut out areas of varying dimension. When the sheets 2 are laminated together the cut out areas enable sections of the back member to have a higher flexibility than other areas or sections. The cut out areas of adjacent laminated sheets are dimensioned so as to provide a gradual transition from an area of high rigidity or stiffness to an area of lesser rigidity or stiffness.

It is realised in the invention that the laminated sheets may be made of many different materials including plastics, metals and composites.

Similarly, the flexible membrane may be made from a variety of flexible materials, and, for example, is suitably made from SISEARA (Trade Mark) webbing. In another embodiment the flexible membrane is made from a rubber material, providing a pirrelli platform.

As shown in the Figures, in preferable embodiments the back member is concave at the lower back area 5 and convex near the mid back area 6. The upper portion 7 of the back member extends rearwardly away from the chair, such that the top of the back member 1 extends in a furthermost rearward direction. The stiffer or more rigid areas are located towards the lower part of the back member such that sufficient support is given to the lower lumbar region of a person's back.

Additionally, the outside edges or perimeter of the back member 1 are relatively stiff, thereby providing a frame 8 around the general planar shape of the back member 1.

The frame 8 may be integral with the laminated sheets 2. In one embodiment this is achieved by the provision of ribs moulded in proximity to the outside edges of the sheets 2, the ribs causing the outside edges of the sheets to be substantially stiff.

Alternatively, the stiffening means for providing a frame integral with the sheets may comprise an increased number of fibres impregnated near the outside edges of the sheets, or larger fibres may be used for this purpose.

In an alternative embodiment the back member may comprise a metal frame, for example steel strips or aluminium extrusions. The flexible membrane and sheets may be stretched between the metallic frame.

In a further embodiment of the invention only one sheet is used, rather than a plurality of laminated sheets and varying rigidity is provided in localised areas, as desired, by the provision of a ribbed or cellular texture, and/or the use of impregnated fibres.

Although not essential to the invention, cushioning means, such as and by way of example only, foam pads may be included on the front surface of the back member and a fabric material may be used to cover the back member. The fabric may be moulded or bonded around the exterior of the sheet or sheets and cushioning means of the back member.

A means of adjustment is provided in the invention which enables the upper section of the back member to be pivoted forward or backward relative to the lower section of the back member. A flexible joint is located between the upper section and lower section of the back member allowing rotational movement of each section in relation to the other.

The flexible joint shown in Fig. 4 comprises a cylindrical male portion 9 in one section dimensioned and adapted to rotate within a cylindrical female bore or aperture 10 in the other section. Tension between the sections may be provided by a compensating spring 12 which is located preferably within the frame 8. The spring has means of adjusting the tension between the two sections.

The invention also provides a further means for varying the degree of flexibility and rigidity throughout the area of the back member. This further means shown in Fig. 5, referred to herein as finger springs, comprises slots 15 cut into one or more sheets 2 of the back member 1. The slots 15 are preferably parallel to enable an increased degree of flexibility in one particular dimension. Thus, as shown in Fig. 5 the finger springs 15 are substantially parallel and of greater length towards the middle of the back member 1 to enable the greater flexibility in that area, the flexibility gradually reducing towards the outside frame 8 of the back member 1.

A yet further means for varying the degree of flexibility and rigidity through the area of the back member 1 is shown in the embodiments of Figs. 6 and 7.

In these embodiments a fluid reservoir 16 is located inside a seat member 23 of the chair. The reservoir 16 may contain any suitable fluid, including an oil, gas or air. Located in the back member 1 are channels 17 which communicate with the fluid reservoir 16 and are adapted to receive the fluid upon compression of the reservoir 16.

The channels 17 for the fluid may be moulded into the back support 1, or alternatively fitted into position inside the moulded or laminated structure and sealed into place. In order to prevent undesirable return of the fluid into the fluid reservoir 16, for example during a momentary release of the pressure on the reservoir 16, non-return valves 18 are located at the base of the channels. The channels 17 may be located, as shown in the Figs, in localised areas of the back member 1 where an increased degree of stiffness or rigidity is required. Furthermore, large areas of the back member 1 may be inflated or extended by this means.

In use, the weight of a person sitting on the seat member 23 causes pressure on the fluid reservoir 16.

The pressurised fluid reservoir 16 causes the fluid to flow into the channels 17 of the back member 21, thereby increasing the stiffness in the localised areas of those channels 17. An advantage of this is that the level of stiffness is proportional to the weight of the sitter.

Referring now to Fig. 8, a chair is provided with a reclining means which enables a seat member 23 and a back member 1 to be reclined, relative to a support stand 20, while maintaining a constant angle between the seat member 23 and the back member 1.

In this embodiment the seat member 23 is hingeably attached to the support stand 20 towards the front and under side of the seat member 23. Internally of the seat member 23 is provided a fixed support lever 21 which is in fixed relationship with the support stand 20. Also within the seat member 23 is a seat frame 22 having a fixed relationship with the seat member 23.

Movement means is provided between the seat frame 22 and the fixed support lever 21, whereby, upon movement, the seat member 23 pivots forward or backward in relationship to the support stand 20.

The movement means may be operated by a cam action in, for example, a spring assisted multi position, wedged assembly. Alternatively, a gas spring action may be used. The spring may be actuable externally of the seat member 23, with the remainder of the assembly including the seat frame 22 and the fixed support lever 21 located inside the seat member 23 and concealed from view.

A similar apparatus may be used to adjust the angle or relationship between the seat member 23 and the back member 1.

Further improvements and modifications may be made without departing from the scope of this invention.

Claims (37)

1 A chair including a back member for supporting a person's back while sitting, wherein the back member is of varying rigidity across its width and/or height.

2 A chair as claimed in Claim 1, wherein the back member includes areas of differing rigidity and strength to provide differing support in certain areas of the back member.

3 A chair as claimed in either preceding Claim, wherein the back member is formed from laminated sheets and a flexible membrane.

4 A chair as claimed in Claim 3, wherein the sheets are made from a thermo-plastic material.

5 A chair as claimed in either Claim 3 or 4, wherein the sheets are impregnated with fibres in localised areas to increase the stiffness and rigidity in those areas.

6 A chair as claimed in any one of Claims 3 to 5, wherein the sheets are moulded with a ribbed or cellular texture, the ribs or cellular texture being adapted to provide increased stiffness and rigidity in localised areas.

7 A chair as claimed in Claim 6, wherein the ribbed or cellular texture allows cushioning of adjacent sheets and compression of the flexible membrane.

8 A chair as claimed in any one of Claims 3 to 6, wherein the sheets are of varying shape, having cut out areas, so as to provide localised areas of greater stiffness and rigidity than other areas within the back member.

9 A chair as claimed in Claim 8, wherein the cut out areas of adjacent laminated sheets are dimensioned so as to provide a gradual transition from areas of a high relative rigidity to areas of a high relative flexibility.

10 A chair as claimed in any one of the preceding Claims, wherein stiffer or more rigid areas are located towards a lower part of the back member and towards an outer frame of the back member.

11 A chair as claimed in any one of Claims 3 to 10, wherein the back member is provided with a fabric, wherein the fabric is moulded around the exterior of the sheets.

12 A chair as claimed in any one of Claims 3 to 10, wherein the fabric is bonded around the exterior of the sheets.

13 A chair as claimed in Claim 11 or 12, wherein cushioning means is provided in the back member and located between the fabric material and the sheets.

14 A chair as claimed in Claim 10, 11, 12 or 13, wherein the outer frame is integral with the sheets, wherein the frame is formed by localised stiffening around the perimeter of the sheets.

15 A chair as claimed in Claim 14, wherein the localised stiffening of the frame is formed from ribs moulded integrally with the sheets.

16 A chair as claimed in any of the preceding Claims, wherein the back member includes a metal frame.

17 A chair as claimed in Claim 16, wherein the metal frame is made from an aluminium extrusion.

18 A chair as claimed in any of the preceding Claims, wherein the back member is concave at the lower back area and convex near the mid-back area.

19 A chair as claimed in Claim 18, wherein the maximum point on the convex profile of the back support is provided with a flexible joint.

20 A chair as claimed in any of the preceding Claims, wherein the back member comprises an upper section and a lower section, wherein the upper section and the lower section are connected by the flexible joint and are adapted to allow rotational movement in relation to each other.

21 A chair as claimed in Claim 20, wherein the flexible joint includes a spring, wherein the tension of the spring is adjustable.

22 A chair as claimed in any one of Claims 3 to 22, wherein one or more of the sheets or flexible membrane are provided with slots which act as finger springs, so as to provide increased flexibility in localised areas.

23 A chair as claimed in any one of Claims 3 to 21, wherein the flexible membrane includes sprung moulded elements which provide a basic form to the membrane in accordance with the shape of a person's back and limit the degrees of freedom of flexibility of the membrane.

24 A chair as claimed in any one of Claims 3 to 23, wherein the membrane is made from SISEARA (Trade Mark) webbing.

25 A chair as claimed in any one of the Claims 3 to 23, wherein the membrane is made from a rubber material.

26 A chair as claimed in any one of Claims 3 to 25, wherein the membrane provides a pirrelli platform.

27 A chair as claimed in Claim 1 or Claim 2, wherein there is provided a chair including a seat member and a back member, wherein the seat member includes a fluid reservoir, wherein the back member includes channels communicating with the reservoir adapted to receive the fluid upon compression of the reservoir, and wherein the receiving of the fluid in the channels causes the back member to be stiffened in the localised areas of the channels.

28 A chair as claimed in Claim 27, wherein the channels are located in areas requiring a relatively greater stiffness and rigidity.

29 A chair as claimed in Claim 27 or 28, wherein the channels include non return valves to control the flow of the fluid back into the reservoir.

30 A chair as claimed in Claim 27, 28 or 29, wherein the quantity of stiffness and rigidity in the localised areas of the back member is proportional to the weight of a person sitting on the seat member.

31 A chair as claimed in any of the preceding Claims, wherein there is provided a chair comprising a seat member, a back member and reclining means, wherein the reclining means enables the chair to be reclined while maintaining a constant angle between the seat member and the back member.

32 A chair as claimed in Claim 31, wherein the seat member is hingeably mounted on a support stand.

33 A chair as claimed in Claim 32, wherein the reclining means comprises a fixed support lever and a seat frame, wherein the fixed support lever is in fixed relationship with the support stand, wherein the seat frame is in fixed relationship to the seat member, and wherein movement means is provided between the seat frame and the fixed support lever.

34 A chair as claimed in Claim 33, wherein the movement means includes a spring assisted multi-position wedged assembly, providing a cam action between the lever and the seat frame.

35 A chair as claimed in Claim 33 or 34, wherein the seat frame and the fixed support lever are located inside the seat member and concealed from view.

36 A chair as claimed in Claim 34 or 35, wherein the spring is a gas spring, actuatable externally of the seat member.

37 A chair substantially as hereinbefore described with reference to the accompanying drawings.