This disclosure relates to the field of ergonomic chairs.
Ergonomic chairs for reducing various stresses on the body that are often related to sitting for long periods of time and/or due to incorrect posture when in the seated position are known and come in a variety of designs. Mesh chairs that provide a mesh or material covering formed from a resilient material that is arranged over a chair frame for supporting the user in the seated position have gained popularity, at least in part for their modern aesthetics. Mesh chairs are also considered advantageous for allowing air flow through the mesh or material covering enabling the user to remain cool when seated in the chair for long periods of time and for being more easily cleaned and/or sterilized than more traditional chairs that include more fabric and cushioning.
Forming one aspect of the invention is a chair comprising a base, a support post extending upwardly from said base; and a seat structure attached to said support post. The seat structure comprises: a frame member defining a central opening; a flexible membrane extending across the central opening of said frame member; and a pair of support pads arranged at a level below the central opening of said frame member.
According to another aspect, the support pads can be rearwardly disposed with respect to the front edge of said frame member by a first distance and are spaced apart from each other by a second distance, the first and second distances generally corresponding to the positioning of the ischicial tuberosity of a user when the user assumes a seated position engaging the seat structure.
Forming another aspect of the invention is a chair comprising a base and a seat structure attached to said base. This seat structure includes: a frame member defining a central opening; a flexible membrane extending across the central opening of said frame member; and a pair of support pads arranged at a level below the central opening of said frame member.
Forming yet another aspect of the invention is a chair comprising a base, a seat structure attached to said base to support the buttocks of a user seated thereupon; and a back rest attached to one or more of the base and the seat structure to support the back of the user. The back rest includes: a frame member defining a central opening; a flexible membrane extending across the central opening of said frame member; and a pad arranged behind the central opening and positioned in the manner of a lumbar pad.
Referring now to
The seat structure 12 is mounted at the upper end of the support post 22. The seat structure 12 includes a frame member 26 that forms the periphery of the seat and defines a central opening 28 therethrough. A cross-beam member 30 having a generally concave or curved structure extends generally below the central opening 28 of the frame member 6 along the midline or centerline 27 of the seat structure 12 interconnecting the front and rear edges 32, 34 of the frame member 26, the cross-beam member 30 serving to mount the seat structure 12 to the upper end of the support post 22. The frame member 26 and cross-beam member 30 may be integrally formed or may be formed as separate components that are fixed together forming the seat structure. The frame member 26 and cross-beam member 30 are formed of molded plastic material.
A pair of cushion supports 38 extend laterally away from the cross-beam member 30, one on either side of thereof. The cushion supports 38 are rearwardly disposed by a distance D1 with respect to the front edge 32 of the frame member 26 and extend laterally away cross-beam member 30 by a distance D2 with respect to the midline or centerline 27 of the seat structure 12. The distances D1 and D2 are predetermined so as to generally correspond to and/or align with the position or general location of the ischicial tuberosity, or sitting bones, of the average user when in a seated position.
The cushion supports 38 are formed as separate components that are securely fixed to the cross-beam member 30. First and second support cushions 40 are secured to the upper surface 42 of the cushion supports 38 and are formed from a suitable padded material to provide a cushioning effect. The cushion supports 38 and support pads 40 are selected and/or together have a predetermined overall thickness or height to ensure that the upper surface 44 of the support cushions 40 lies at a level below the central opening 28 of the frame member 26 when arranged or mounted on the cushion supports 38.
As shown in
It is generally understood that a person in a seated position rests on the ischicial tuberosity, or sits bones, which extend from the lower, back portion of the pelvis or hip bones. When a person is standing, the ischicial tuberosity is generally covered by large muscle groups that generally provide cushioning or padding to the otherwise bony protrusions of the ischicial tuberosity. However, when a person assumes a seated position, the muscles tend to shift leaving the bony protrusions of the ischicial tuberosity to bear the majority of the weight. Bearing the majority of one's weight on the ischicial tuberosity can be quite uncomfortable especially when one is in a seated position for a long duration of time, as is often typical of an office workplace situation. As well, depending on the size and overall weight of the user, when mesh is utilized, it has been discovered that pressure points may also be created against the backs of the user's legs and/or on their hips or thighs where the edges of the frame member may come into contact with and impinge on the user's body.
In the embodiment shown in
A third support pad 52 is also provided at the front end 54 of the cross-beam member 30 proximal to the front edge 32 of the frame member 26. The third support pad 52 is arranged so as to generally lie between the user's legs when in the seated position on the chair 10. Accordingly, the third support pad 52 provides additional support to membrane 50 in the area proximal the front edge 32 of the frame member 26 along the centreline or midline 27 of the seat structure 12. The third support pad 52 extends laterally on either side of the centreline or midline 27 of the seat structure 12 by a distance D3 and is generally sized and arranged below the central opening 28 of the frame member 26 so as not to come into contact with the user's legs when seated on the chair 10. The third support pad 52, therefore, provides support to only the membrane 50 at the front edge 32 of the seat structure 12. The third support pad 52 therefore works in combination with the first and second support pads 40 that are arranged within the central area of the seat structure 12 to provide a support triangle for providing additional support the membrane 50 under the weight of a user allowing the membrane 50 to adopt a more comfortable position without undue shear stresses being created in the material resulting in a more ergonomic and a more comfortable feel for users of various overall weights and/or sizes. Reducing the amount of shear stresses created in the membrane 50 when under the weight of a user also tends to increase the life of the material forming the membrane 50 over time.
In the embodiment shown, the back rest 14 is similar in structure to the seat structure 12 in that it comprises a frame member 58 that forms the periphery of the back rest 14 and defines a generally elongated, central opening 60. A back support member 62 extends generally along the centerline or midline of the back rest 14 interconnecting the top and bottom edges 64, 66 of the back frame member 58. A second membrane (not shown) is generally arranged across the top of the frame member 58 so as to extend across the central opening 60 defined by the frame member 58. Similar to the membrane 50 used on the seat structure 12, the membrane for the back rest is formed by a mesh material that can stretch and conform to the shape of the user's back when the user rests against the back rest 14 of the chair. The back rest 14 is mounted to the base 16 by tilt mechanism in order to permit limited, pre-determined movement of the back rest 14 (e.g. forward tilt, backwards tilt) with respect to the base independent of the seat structure 12. The back rest 14 may also be provided with additional features such as an adjustable lumbar support mechanism and/or a head rest (not shown) positioned at the upper edge 64 of the back rest 14.
By providing both a back rest 14 and a seat structure 12 formed by frame members 26, 58 fitted with a resilient mesh membrane 50, 63 arranged across the central openings 28, 60 of the frame members 26, 58 allows for air-circulation around and through both the seat structure 12 and back rest 14. As well, since membranes used for both the seat structure 12 and the back rest 14 are generally spaced apart from the supporting structures (e.g. frame members 26, 58 and cross-beam members 30, 62) forming both the seat structure 12 and back rest 14, the chair 10 can be relatively easily cleaned since the components of the seat structure 12 and back rest 14 are accessible, which is advantageous in environments requiring a degree of cleanliness. Furthermore, by providing a seat structure 12 having a combination membrane and support cushion structure as described above, a comfortable and durable chair 10 is provided that is suited to a wide range of individual users.
A further exemplary embodiment shown in
Without intending to be bound by theory, it has been found that an advantageous arrangement of the cushion provided by pads 40 (and 52, when present) is associated with support pads providing the maximum amount of support possible without the user feeling the pads in use. Accordingly, the technology can advantageously be deployed with removable pads of differing densities (to enable users to customize the chair by substitution of pads) or with pads having adjustable air bladders or otherwise adjustable in height relative to the frame or adjustable in stiffness.
A further embodiment is shown in
While but three embodiments of the chair and seat structure have been illustrated and described, it will be understood that certain adaptations and modifications can be made. For example, whereas the chairs shown each include a support post, this need not be the case; the chair could be made with four legs and non-swivelling.
Therefore, the above discussed embodiments are considered to be illustrative and not restrictive.
This Application claims the benefit of U.S. Provisional Application 62/404,856 filed on Oct. 6, 2016. This Application is a Continuation-in-part of Application PCT/CA2015/050771 filed on Aug. 13, 2015. Application PCT/CA2015/050771 claims the benefit of U.S. Provisional Application 62/066,440 filed on Oct. 21, 2014. Application PCT/CA2015/050771 claims the benefit of U.S. Provisional Application 62/036,805 filed on Aug. 13, 2014.
Number | Name | Date | Kind |
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4883320 | Izumida | Nov 1989 | A |
6609755 | Koepke | Aug 2003 | B2 |
6957861 | Chou | Oct 2005 | B1 |
7434888 | Lin | Oct 2008 | B2 |
7731295 | Lin | Jun 2010 | B2 |
7837265 | Machael | Nov 2010 | B2 |
7878590 | Bilak | Feb 2011 | B1 |
Number | Date | Country |
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2319884 | Dec 2001 | CA |
Entry |
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International Preliminary report, Written Opinion, International Application No. PCT/CA2015/050771, 6 pages, dated Feb. 14, 2017. |
Number | Date | Country | |
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20170127839 A1 | May 2017 | US |
Number | Date | Country | |
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62404856 | Oct 2016 | US | |
62066440 | Oct 2014 | US | |
62036805 | Aug 2014 | US |
Number | Date | Country | |
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Parent | PCT/CA2015/050771 | Aug 2015 | US |
Child | 15405963 | US |