The present invention relates to a chair and, in particular but not exclusively, to a chair of the kind used in an office environment.
Over recent years, office working practices have evolved. ‘Knowledge-based’ workers are no longer based at the same desk each day and the workplace is becoming more focused on collaboration in order to drive innovation across multi-disciplinary platforms. Offices are evolving to become a place where workers ‘touch-down’ for shorter periods of time, and where ‘hot-desking’ is becoming the norm in a range of businesses. Whereas once every employee had their own desk and their own chair, businesses are now under pressure to gain greater efficiencies by increasing the ratio of people to desks, therefore eliminating the need for banks of desks that may previously have been only partially filled at any given time.
From a seating perspective, the traditional ‘eight-hour’ (i.e. full working day), fully-ergonomic, manually adjusted task chair is no longer required in every case. However, providing a smaller number of desks and chairs, for use by a variety of different people at different times may be problematic. Physical characteristics such as height, weight, build, posture etc. vary from person to person. A chair that would be comfortable for a tall person of heavy build may not be suitable for a shorter, leaner person. Typically, office chairs are manually adjustable such that a person can vary the chair settings to a set-up that is comfortable for them. This may involve manually adjusting the height of the seat above the ground, or the inclination of the backrest. However, if a chair is being used by a number of different people in a ‘hot desk’ environment, each person will either need to adjust the chair each time they use it after someone else, or they will endure using a chair that has been used by someone else, even though their settings may be inappropriate leading to discomfort and potential injury.
U.S. Pat. No. 4,429,917 by Diffrient discloses a tilting-type chair including a base, a seat, and a back. The back of the U.S. Pat. No. 4,429,917 chair is fixedly connected to a frame of the chair and cannot swivel relative to the frame. In U.S. Pat. No. 4,429,917, a mechanism effects that the seat and the back both tilt in a ratio of about 1 to 3, to prevent that only the back tilts or that the seat and back tilt as a unit.
WO 00/67615 by Bujaryn describes a chair comprising a seat pan and an armrest support pivotably attached to a mounting assembly comprising a lower and an upper rail. The potential maximum rearward tilt of the seat pan is limited by the tilt of the mounting assembly, and if the mounting assembly is not fully titled, the seat pan cannot achieve its maximum rearward tilt.
The subject of U.S. 2007/0222265 A1 by Machael is an adjustable reclining chair in which a force applied onto a back-upright of a chair is re-directed by the back-upright to lift the seat assembly. The seat assembly cannot pivot independently.
The present invention has been devised with the foregoing in mind.
According to the present invention there is provided a chair. The chair provides a combination of independent pivoting movements which work together to adapt to a user whilst still allowing the complete chair to move into and out of a reclined position.
Advantageously, embodiments of the chair of the present invention caters for the new way of working discussed above, by offering more comfort and support than a meeting chair whilst still being dynamic. Embodiments of the invention allow the body to move like it does in a task chair, but without the plethora of manual adjustments traditionally found on a task chair.
In an embodiment, the chair comprises a backrest, a seat, a supporting structure for supporting the backrest and/or the seat and a base support, wherein the supporting structure, the seat and the backrest are each pivotably mounted to permit the supporting structure, the seat and the backrest to each tilt over a predetermined range, to allow the chair to move into and out of a reclined position. The seat is free to pivot over its predetermined range relative to the supporting structure independently of any tilt of the supporting structure. In an embodiment, the backrest is free to pivot over its predetermined range relative to the supporting structure independently of any tilt of the supporting structure. Preferably the supporting structure is pivotably mounted with respect to the base support, the seat is pivotably mounted with respect to the supporting structure and the backrest is pivotably mounted with respect to the supporting structure.
In an embodiment, the chair further comprises a seat tilt mechanism that permits the seat to pivot about a pivot point and with respect to the base support such that the seat is tiltable between a first limit in a first direction and a second limit in a second and opposite direction, the first limit and the second limit defining the predetermined range of the seat. The seat tilt mechanism may comprise a component for regulating or dampening the motion and return of the seat during tilting. Preferably, the component is or comprises a pre-tensioned or resiliently deformable component that is deformable when the seat is tilted in one or each direction. The component may be or comprise a spring steel member, a spring, an elastomeric member, or a hydraulic dampener. The first and second limits may be defined by stop positions on the supporting structure. In an embodiment, the seat is tiltable from a neutral position at substantially 0° to the first limit of approximately +5° and to the second limit of approximately −5°.
In an embodiment, the chair further comprises a backrest tilt mechanism that permits the backrest to pivot about a pivot point with respect to the supporting structure such that the backrest is tiltable between a first limit in a first direction and a second limit in a second and opposite direction, the first limit and the second limit defining the predetermined range of the backrest. Preferably, the backrest tilt mechanism comprises a component for regulating or dampening the motion and return of the backrest during tilting. The component may be or comprise a pre-tensioned or resiliently deformable component that is deformable when the backrest is tilted in one or each direction. Preferably, the component is or comprises a spring steel member, a spring, an elastomeric member, or a hydraulic dampener. The first and second limits may be defined by stop positions on the supporting structure. The backrest may be tiltable from a neutral position to the first limit of approximately −12°.
In another embodiment, the chair further comprises a tilt mechanism that permits the supporting structure to pivot about a pivot point with respect to the base support such that the supporting structure is tiltable between a first limit in a first direction and a second limit in a second and opposite direction, the first limit and the second limit defining the predetermined range of the supporting structure. The tilt mechanism may comprise a component for regulating or dampening the motion and return of the backrest during tilting. The component may be or comprise a pre-tensioned or resiliently deformable component that is deformable when the backrest is tilted in one or each direction. The component may be or comprise a spring steel member, a spring, an elastomeric member, or a hydraulic dampener. The component may be one or more compression springs. The first and second limits may be defined by one or more buffers provided within the tilt mechanism. The supporting structure may be tiltable from a neutral position (approximately 0°) to the first limit of approximately −9°.
Embodiments of the invention will now be described with reference to the following drawings, in which:
a show a chair 10 according to an embodiment of the present invention. The chair 10 has a base 12 comprising a plurality of legs 14. In the embodiment shown there are five legs provided equally spaced around the centre of the base. The legs 14 extend radially away from a central sleeve 16 that surrounds and is coupled to an inner sleeve or receptacle 18. The other end of each leg 14 comprises a castor 20. The inner sleeve (gas lift) 18 is configured to receive a first end of vertical member or shaft 22, the other (second) end of which is coupled to a seat assembly 24, which will be discussed in greater detail below. The shaft 22 may be rotatably mounted within the sleeve 18 so as to permit rotating/swivelling movement between the seat assembly 24 and the base 12. The central shaft 22 is connected to the outer sleeve 18 via a bearing ring and is prevented from being pulled out of the top by a locking washer on the underside thereof. The gas lift 18 is connected to the base 12 via a morse taper of 1°.
The second end of the shaft 22 is received within a support 26 that forms a base for the seat assembly 24. The support 26 also houses a ‘tilt mechanism’ that enables a pivoting or rocking movement of the seat assembly 24 with respect to the shaft 22 and base 12. To the support 26 is attached a supporting structure or cradle 28. Two cradle base arms 30 are coupled to the base support 26, on opposite sides thereof. Each cradle arm 30 extends laterally outwardly with respect thereto, in opposing directions (in the x direction of
The seat assembly 24 further comprises a seat 36 comprising a frame 38 and seat pad 40. The seat assembly 36 is attachable to the cradle 28 at fixing locations 42. The height of the seat 36 is adjusted manually via a small ‘seat height pull’ lever (19 as shown in
The seat assembly 24 also comprises a backrest 44, which itself also comprises a frame 46 and a pad 48. Each of the ends of the cradle arms 34 is connectable to the backrest at fixing locations 50.
In a neutral (or starting) position, e.g. before a person sits on the chair 10, the cradle 28 is in position ‘A’, the seat 36 is in position ‘C’ and the backrest is in position ‘F’. As can be seen in
It is evident from a comparison of
It is evident from
However,
Referring now to
Each cradle base arm 30 terminates in an end portion 52. Each end portion 52 is configured with a hollow portion or recess 54. When placed adjacent to each other, the recesses 54 in the ends 52 of the cradle arms 30 define a larger recess that is sized to receive the support block 26. Since the ends 52 of the cradle arms 30 meet without any discontinuity therebetween, this gives the impression that the lower part of the cradle 28 is continuous, e.g. as can be seen in
Reducing discontinuities reduces the risk of body parts, e.g. fingers, becoming entrapped. As the ends 52 of the cradle arms 30 are received without discontinuity in the support block 26, this improves the safety of the mechanism.
The support block 26 comprises two apertures 58, in each of which is provided an annular bearing 60. An axle 62 (e.g. formed of steel) is located within the apertures 58 and is rotatable therein. Each end of the axle 62 is located within one of the end portions 52 of the cradle arm 30 so as to couple the cradle arms 30 to the support block 26 and permit relative movement therebetween. The cradle 30 can thus pivot with respect to the support block 26 which is fixed relative to the shaft 22 and base 12. The pivoting motion is dampened or regulated by two coiled steel springs 64. Bearings 66 are provided at each end of the springs 64 to help constrain the motion of the spring and reduce friction between the springs 64 and the support block 26. Four rubber buffers 70, 72 are provided on the upper surface of the support block 26, to act as movement limiters or stops. A first pair of buffers 70 is provided along a first edge 74 of the support block 26 and a second pair of buffers 72 are provided along a second edge 76 of the support block 26.
The pivoting motion enables the cradle to move between a first position as shown in
When a user sits on the chair 10, the action of sitting down can cause the cradle 28 to tilt backwards at the pivot point 62, into the position depicted in
Referring now to
A resiliently biased component 90 is also provided with the backrest frame 44, e.g. in the form of a spring steel bar. A first end 92 thereof is received in and supported by a recess 94 in the connector 84 (as can be seen in
Referring now to
The connector 100 further comprises a housing 112. A resiliently biased component such as a spring steel bar 116 is passed through and is supported by the housing 112 approximately half way along its length. A first end of the spring steel bar 116 is received and fixed within a recess 120 provided within the seat frame 44. A second and opposite end of the spring steel bar 116 is received and fixed within a recess 122 provided within the seat frame 44. As such, a first portion 118 of the spring steel bar 116 is located on one side of the housing 112, and a second portion 118′ of the spring steel bar 116 is located on the other side thereof. The bearing 104 is configured with first and second bearing surfaces 124, 126. The seat frame 44 comprises first and second stop surfaces 128, 130 respectively configured to abut the first and second bearing surfaces at first and second movement limits as will now be described.
In a preferred embodiment, the bearing 14 and seat frame 38 are configured such that the stops 128, 130 provide a rotation with respect to pivot point K of approximately 5° in each direction with respect to the horizontal. It will be appreciated that the bearing surfaces 124, 126 and the stop surfaces 128, 130 may be configured (e.g. by altering the angle, position, size thereof) to provide a different maximum movement limit. The range of movement may e.g. be up to approximately ±8° or more, or e.g. ±7.5°, ±7°, ±6.5°, ±6°, ±5.5°, ±4.5°, ±4°, or ±3° or less. The chair 10 may also be configured such that tilting in one direction only is permitted.
Embodiments of the present invention advantageously create a fully dynamic chair 10, which tilts, turns and fully supports an anthropometrically broad range of users, but which is more intuitive, eliminating the need for manual adjustment by the user. A chair 10 according to embodiments of the present invention would lend itself to the modern workplace, where people can be sat in several different places and on several different chairs each day, by taking away the time-consuming requirement to ‘set-up’ the chair to suit a particular user, therefore making the need for training redundant, which can be currently a costly part of each employer's duty-of-care. Advantageously embodiments of the invention provide a combination of features that provides for seat, back and tilting movement without the need for manual adjustment.
An embodiment of a chair 10 according to the present invention has undergone an ergonomics assessment. The seat height was adjusted so that all the users were able to sit on the chair with their feet flat on the floor (no undue pressure at the back of knees). The ergonomics assessment consisted of 10 people (4 females and 6 males) with varying stature from 5th to 95th centile UK population sitting on the chair which was part of a rig. Subjects sat on a pressure map on the seat pad 40 and backrest 44 and their pressure profiles were recorded.
As the backrest 44 comprises a mesh back 48 without a lumbar device, in order to determine how well the mesh deforms whilst still providing good lumbar support automatically for different sizes of people, the spines of the test subjects were traced when they were standing, when they are sitting on a box in a relaxed (semi-slouched) posture and when leaning back on the mesh backrest 48. The working assumption was that if the mesh back 48 gives a good support and automatically adjusts to the user's back, the tracing of their spines when seated in the chair 10 should be more like the shape of standing posture, not like the sitting slouched posture.
In addition users were questioned about the overall feel and comfort of the chair, and their likes and dislikes about the chair. Users were asked about levels of discomfort experienced at different parts of their body. Discomfort assessment is used as physiologically people have discomfort (pain) sensors not comfort sensors.
Preliminary measurements of the chair 10 in the rig gave the following approximate dimensions:
Dimensionally most of the test subjects were happy with the dimensions of the chair 10, and it was possible to obtain a correct seat height for each user by adjusting the seat height. It was found that the seat depth was appropriate to cover the range of users of different heights and stature and any significant departure therefrom could potentially be to the detriment of some users.
Analysis of the pressure mapping of the backrest 44 and the spinal tracing showed that the mesh back 48 sufficiently deforms and adapts the back of the user and provides adequate support around the lumbar area. Responses of the users supported this, in a way that they all felt a good lumbar support. In most instances, spinal tracing showed the lumbar protrusion of the curve, but there was no evidence of slouching from any of the users. Pressure mapping of the users' backs also showed the support around the lumbar.
Pressure distribution of the seat pad 40 was generally good—only a couple of traces showed high pressure points and only one user felt some awareness of firmness under their pelvis.
Users found the resistance of backrest to pivot was about right—no user found it to be too strong or too weak.
In conclusion, the concept of a pivoting backrest 44 and pivoting seat pad 36 is beneficial to a user in terms of encouraging dynamic sitting. Having only a pivoting backrest is not sufficient. A pivoting seat pad 36 additionally allows a user to automatically open up the angle between their thighs and torso. This not only improves the user's breathing, and hence the blood supply to the brain (keeping them alert and more productive), but also helps them to exercise their core muscles which can help towards avoiding back pain and discomfort.
The independent full-range tilt of the seat 36 and backrest 44 relative to the cradle 28 permits the chair to compensate for micro-movements of a person sitting in it. For instance, a person may sit upright at a desk and momentarily stretch their feet. The seat 36, being independently swivelable, is able to swivel forward in response to the more inclined angle of the upper thighs and continue to support the upper thighs without the seat's forward edge pressing into the underside of the thighs. Upon bending the legs back to an upright sitting position, the tilt of seat 36 follows the angle of the upper thighs and returns to a more horizontal attitude. The responsiveness and range of the seat 36 is independent of the tilt of the cradle 28 or the backrest 44. This provides a continuously responsive, adaptive chair configuration that by some test persons has been described as “fluidic”, without requiring a user to manually adjust a seat or backrest.
Number | Date | Country | Kind |
---|---|---|---|
1412733.6 | Jul 2014 | GB | national |
1506323.3 | Apr 2015 | GB | national |
Number | Name | Date | Kind |
---|---|---|---|
3598354 | Williams | Aug 1971 | A |
3669399 | Wager | Jun 1972 | A |
4429917 | Diffrient | Feb 1984 | A |
4911501 | Decker et al. | Mar 1990 | A |
5080318 | Takamatsu | Jan 1992 | A |
5121934 | Decker | Jun 1992 | A |
5150948 | Voelkle | Sep 1992 | A |
5267777 | Valtri | Dec 1993 | A |
5582459 | Hama et al. | Dec 1996 | A |
5871256 | Kogai | Feb 1999 | A |
5871258 | Battey | Feb 1999 | A |
6116687 | Vogtherr | Sep 2000 | A |
6869142 | Heidmann | Mar 2005 | B2 |
6880886 | Bodnar | Apr 2005 | B2 |
6932430 | Bedford | Aug 2005 | B2 |
6935962 | Tseng | Aug 2005 | B1 |
7048335 | Norman | May 2006 | B2 |
7857390 | Schmitz | Dec 2010 | B2 |
8029060 | Parker | Oct 2011 | B2 |
8061767 | Kunzler | Nov 2011 | B2 |
8087727 | Parker | Jan 2012 | B2 |
9033421 | Wilkinson | May 2015 | B2 |
20020149247 | Diffrient | Oct 2002 | A1 |
20070222265 | Machael | Sep 2007 | A1 |
20150173515 | Freedman | Jun 2015 | A1 |
Number | Date | Country |
---|---|---|
29711329 | Aug 1997 | DE |
29802360 | Jun 1999 | DE |
1163865 | Dec 2001 | EP |
1872688 | Jan 2008 | EP |
2946694 | Nov 2015 | EP |
1276274 | Jun 1972 | GB |
2414391 | Nov 2005 | GB |
0067615 | Nov 2000 | WO |
2010041518 | Apr 2010 | WO |
2013131753 | Sep 2013 | WO |
Entry |
---|
Search and examination report for GB1412733.6 dated Jan. 12, 2015. |
European Search Report in EP 15177024.5 dated Nov. 27, 2015. |
Search and Examination Report in GB 1506323.3 dated Sep. 28, 2015. |
Combined Search and Examination Report issued by IPO in connection with GB1506323.3 dated Sep. 28, 2015. |
Examination Report issued by IPO in connection with GB1506323.3 dated May 29, 2018. |
Examination Report issued by IPO in connection with GB1506323.3 dated Aug. 9, 2017. |
Number | Date | Country | |
---|---|---|---|
20160015179 A1 | Jan 2016 | US |