WO2006034523A1

WO2006034523A1 - A chair

Info

Publication number: WO2006034523A1
Application number: PCT/AU2004/001334
Authority: WO
Inventors: Peter George Gordon Gregory
Original assignee: Gregory Industries Limited
Priority date: 2004-09-29
Filing date: 2004-09-29
Publication date: 2006-04-06

Abstract

This invention provides a chair (1) including a seat (2) for supporting weight of a person (12) sitting on the chair; said seat including a resiliently deformable support portion (6) and a transversely extending ridge (8), said ridge dividing said support portion into a front support portion (9) and a rear support portion (10), said ridge being of relatively high resistance to deformation and said rear support portion being of relatively low resistance to deformation such that the weight of the person sitting on the chair causes said rear support portion to be deformed to a greater extent than the ridge and acting to locate the person's ischial tuberosity (13) behind the ridge thereby resisting forward movement of the person from the chair and thus retaining the sitter in a correct seating position.

Description

TITLE: A CHAIR

TECHNICAL FIELD

The present invention relates to chairs and in particular to a chair which enables the occupant to be seated with correct posture.

BACKGROUND ART

Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

An occupant of a chair seated with correct posture should have his back relatively straight with the spine having a slight bow at its lower portion. Correct posture can prevent and alleviate back pain. To this end, chair designs have been continually refined in order to ensure that the occupant is seated with the correct posture to minimize and hopefully eliminate back pain.

One example of a chair which positions the occupant for correct posture is a chair having a seat which slopes forward. This seeks to ensure that the occupant is positioned with a straight back. To complement the sloping seat, a knee rest can be provided to prevent the occupant from sliding forwardly off the seat. However, a disadvantage of this seat is that the pressure exerted on the knees can become uncomfortable after long periods of time. Various attempts have been made to design a chair that will insure correct posture and one such chair has been invented by the subject inventor as disclosed in US Patent No. 4,889,387. The chair in question while very satisfactory is somewhat complex and sufficiently costly that it does not lend itself to being used in a chair that is priced sufficiently low to reach a mass market and thus provide the desired benefit to a very large number of consumers, hi essence there has long been a need to provide a relatively low cost chair that will maintain a sitter in the desired correct posture while resisting forward movement of the sitter from the seat.

It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a chair including a seat for supporting weight of a person sitting on the chair; said seat including a resiliently deformable support portion and a ridge, said ridge dividing said support portion into a front support portion and a rear support portion, said ridge being of relatively high resistance to deformation and said rear support portion being of relatively low resistance to deformation such that the weight of the person sitting on the chair causes said rear support portion to be deformed to a greater extent than the ridge and acting to locate the person's ischial tuberosity behind the ridge thereby resisting forward movement of the person from the chair and thus retaining the sitter in a correct seating position.

According to a second aspect of the invention there is provided a seat member, said seat member including a resiliently deformable support portion and a ridge, said ridge dividing said support portion into a front support portion and a rear support portion, said ridge being of relatively high resistance to deformation and said rear support portion being of relatively low resistance to deformation such that the weight of the person sitting on the chair causes said rear support portion to be deformed to a greater extent than the ridge and acting to locate the person's ischial tuberosity behind the ridge thereby resisting forward movement of the person from the chair and thus retaining the sitter in a correct seating position.

BRIEF DESCRIPTION OF DRAWINGS

A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Fig. 1 is a sectional side elevation of a chair according to one embodiment of the invention and showing a schematic skeletal occupant seated with correct posture;

Fig. 2 is an enlarged sectional perspective view of the chair seat shown in Fig. 1;

Fig. 3 is a sectional perspective view of a seat according to the invention;

Fig. 4 is a sectional side elevation of a chair according to a further embodiment of the invention and showing a schematic skeletal occupant seated with correct posture; and Fig. 5 is an enlarged sectional perspective view of the chair seat shown in Fig. 4.

DESCRIPTION OF PREFERRED EMBODIMENT(S)

Referring to Fig. 1 a side elevation view of a chair 1 incorporating the present invention is illustrated. It is to be noted that the illustrated chair is merely representative of a chair that would employ the novel seat construction of the invention. While various adjustment features will be disclosed and referred to these features are typically common to chairs of this type and are not essential to the invention. Such features are described and illustrated so that one may have a complete understanding of the operation and construction of a chair and the environment in which the invention is used.

The chair 1 includes a seat 2 for supporting the weight of a person sitting on the chair. A back rest 4 may be provided to give additional support if required. The chair 1 is adjustable in conventional fashion to provide the required height and inclination of the seat 2 and the back rest 4.

As shown in Figs. 1 and 2, the seat 2 includes a base 5 to which is attached a support portion 6 formed from resilient foam plastics material. The support portion 6 includes an outer face 7 upon which the occupier is seated. In the embodiment depicted, the support portion 6 is upholstered with a suitable covering secured to the base 5. In accordance with the invention, the base 5 includes a ridge formation 8 which lies below the outer face 7 of the support portion 6 and which effectively divides the support portion 6 into a forward support portion 9 and a rear support portion 10. The ridge 8 extends transversely; that is, across the width of the seat, and in a preferred form the ridge 8 extends across substantially the full width of the seat. The ridge 8 may have a variety of cross-sectional profiles, such as triangular, bell- shaped or dome-shaped, hi one embodiment, the support portion 6 is formed with a correspondingly shaped recess in its lower face to receive the ridge 8. The recess may be integrally formed in the lower face of the support portion, or may be formed by removing material from the lower face. In one embodiment the ridge is formed from a foam material of greater resistance to deformation than the material forming the support portion 6, and in one particular embodiment, the ridge is formed from a foam material of greater density than the foam material forming the rear support portion 10. In a preferred form, the ridge 8 is of the order of 30 to 120 mm wide and located between 20 to 60% along the length of the seat when measured from the rear edge of the seat. In one embodiment, the ridge 8 may be integrally formed as part of the base 5 of the seat. For example, the ridge 8 may be integrally moulded as part of the base 5. In an alternative embodiment the ridge 8 may be separately formed to the seat base 5.

In a preferred embodiment the front and rear support portions are integrally formed. However it should be noted that the front and rear support portions may be separately formed and may be formed of materials of differing densities. In one embodiment, the ridge 8 is formed from a foam material of greater resistance to deformation than the foam material forming rear support portion 10. The rear support portion of the seat is formed of a material more easily deformed than the ridge, such that a movement of the user's buttocks from the rear seat portion towards the front seat portion urges the rear seat portion towards the ridge 8 thereby deforming the rear seat portion and inhibiting the buttocks from moving towards the front of the seat portion. When an occupant 12 is correctly seated on the chair 2, as shown in Fig. 1, the occupant's ischial tuberosity 13 is located behind the ridge 8. The ridge 8 positively acts against the ischial tuberosity and comfortably resists the tendency of the occupant to slide forwardly on the seat. In this way, the ridge 8 acts to reduce anterior rotation of the pelvis.

Fig. 3 shows a second embodiment of the invention in the form of a cushion 14 which may be portable and which can be placed upon a conventional horizontal bench or seat (not shown). The cushion 14 is similar to the seat 2 illustrated in Figs. 1 and 2 but has an upper surface 15 which inclines rearwardly. The forward support portion 9 is correspondingly inclined and in this embodiment also defines a base for the cushion. The rear support portion 10 extends forwardly over the forward portion 6 to define a relatively soft and shallow covering 16 for the forward portion. The forward support portion 6 defines a shoulder 17 which acts as a ridge 7 in the manner described above. The principal of operation of the cushion 14 is the same as that of the chair 1. The cushion 14 may also be constructed in the manner shown in Figs. 1 and 2. In a further embodiment of the invention depicted in Figs. 4 and 5, the seat base may be provided with a pair of transversely extending ridge formations 8a, 8b in order to locate the ischial tuberosity of the occupant in the correct location on the seat. The forward most ridge 8a stops forward slide of the pelvis, whilst the rear most ridge 8b stops posterior roll of the pelvis which causes damaging Kyphosis (C-curve) of the spine. The ridges 8a, 8b may be integrally formed in the seat base or separately formed from a material of higher resistance to deformation than the material forming the rear support portion of the seat. The ridges may have a variety of cross-sectional profiles, such as triangular, bell-shaped, or dome-shaped. Although the invention has been described with reference to specific examples it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Claims

1. A chair including a seat for supporting weight of a person sitting on the chair; said seat including a resiliently deformable support portion and a ridge, said ridge dividing said support portion into a front support portion and a rear support portion, said ridge being of relatively high resistance to deformation and said rear support portion being of relatively low resistance to deformation such that the weight of the person sitting on the chair causes said rear support portion to be deformed to a greater extent than the ridge and acting to locate the person's ischial tuberosity behind the ridge thereby resisting forward movement of the person from the chair and thus retaining the sitter in a correct seating position.

2. A chair as claimed in claim 1 wherein said ridge is formed from a foam material.

3. A chair as claimed in claim 1 wherein said seat includes a base and said ridge is integrally formed as part of said base.

4. A chair as claimed in claim 1 wherein said seat includes a pair of ridges positioned to locate the ischial tuberosity of the occupant in the correct location on the seat.

5. A chair as claimed in claim 1 wherein said support portion includes an outer face upon which the occupier is seated when occupying the chair, said ridge lying below said outer face of the support portion.

6. A chair as claimed in claim 1 wherein said seat includes a base and said ridge is separately formed to the said base.

7. A chair as claimed in claim 1 wherein said support portion includes a recess which receives said ridge.

8. A seat member, said seat member including a resiliently deformable support portion and a ridge, said ridge dividing said support portion into a front support portion and a rear support portion, said ridge being of relatively high resistance to deformation and said rear support portion being of relatively low resistance to deformation such that the weight of the person sitting on the chair causes said rear support portion to be deformed to a greater extent than the ridge and acting to locate the person's ischial tuberosity behind the ridge thereby resisting forward movement of the person from the chair and thus retaining the sitter in a correct seating position.

9. A seat member as claimed in claim 8 wherein said ridge is formed from a foam material.

10. A seat member as claimed in claim 8 wherein said seat member includes a base and said ridge is integrally formed as part of said base.

11. A seat member as claimed in claim 8 wherein said seat member includes a pair of ridges positioned to locate the ischial tuberosity of the occupant in the correct location on the seat.

12. A seat member as claimed in claim 8 wherein said support portion includes an outer face upon which the occupier is seated when seated on the seat me mber, said ridge lying below said outer face of the support portion.

13. A seat member as claimed in claim 8 wherein said seat member includes a base and said ridge is separately formed to the said base.

14. A seat member as claimed in claim 8 wherein said support portion includes a recess which receives said ridge.