An adjustable chair

Abstract

An adjustable chair 10 comprising a seat 21 to support a seat occupant and a frame 14, where the seat is slidingly moveable in a lateral plane relative to the frame. The sliding movement in the lateral plane may be in at least two directions perpendicular to each other, or in any direction. There may be a seat support housing (24, fig 2) in which the seat is rotatably movable in, and rotatably tiltable out, of the lateral plane relative to the frame in any direction, with the housing slidingly moveable in a lateral plane. Also disclosed is an adjustable chair with a seat is tiltable out of a lateral plane relative to the frame in any direction, and an adjustable chair with a seat rotatably tiltable relative to the frame in an arc about a pivot point (P, fig 26) which is vertically spaced above a surface of the seat.

Description

The present invention relates to an adjustable chair. Adjustable chairs typically comprise a frame having a seat upon which the occupant sits, a plurality of legs which support the seat on the ground, an arm support to support the occupant’s arms, and a back support to support the occupant’s back when sitting on the seat, the arm support and the back support being fixed to the seat. Such known adjustable chairs are adjustable to the extent the seat, the arm support and the back support can be rotated and tilted backwards and forwards relative to the frame of the chair. One problem associated with such known adjustable chairs, is that the tilting movement is restricted to forwards and backwards tilting movement about a hinged joint positioned below the seat which can prevent the occupant from achieving a comfortable sitting position. A further problem associated with such known adjustable chairs is the adjustable movement is restricted to rotating and the limited forwards and backwards tilting movement only, which can also prevent the occupant from achieving a comfortable sitting position. An object of the present invention is to provide a more comfortable adjustable chair. Thus according to the present invention there is provided an adjustable chair comprising a seat to support a seat occupant and a frame, in which the seat is slidingly moveable in a lateral plane relative to the frame. Preferably, the seat is slidingly moveable in the lateral plane in at least two directions that are perpendicular to each other. Preferably, the seat is slidingly moveable in the lateral plane in any direction. Preferably, the seat is rotatably movable in the lateral plane relative to the frame. Preferably, the seat is rotatably tiltable relative to the frame out of the lateral plane. Preferably, the seat is rotatably tiltable relative to the frame in any direction. Advantageously, the ability of the seat of the chair to be adjusted by sliding, rotating and tilting in any direction in response to the seat occupant adjusting his or her body position during use enables the seat to freely move to the seat occupant’s adjusted position and provide the seat occupant with a more comfortable and supported position when compared to a seat without such adjustment. Preferably, the adjustable chair further comprises a seat support housing, and the seat is rotatably movable in, and rotatably tiltable out, of the lateral plane relative to the seat support housing, the seat support housing is slidingly moveable in a lateral plane relative to the frame. Preferably, the adjustable chair further comprises a bowl, in which the seat is fixed to the bowl, the bowl is rotatably movable in, and rotatably tiltable out, of the lateral plane relative to the seat support housing. Preferably, at least one bearing is provided between the seat support housing and the bowl. Preferably, the at least one bearing is provided on one of the seat support housing or the bowl, the at least one bearing engages with the other of the seat support housing or the bowl. Preferably, the adjustable chair further comprises a bearing plate which is fixed to the frame, in which the seat support housing is slidingly and rotatably moveable relative to the bearing plate. Preferably, at least one bearing is provided between the seat support housing and the bearing plate. Preferably, the at least one bearing is provided on one of the seat support housing or the bearing plate, the at least one bearing engages with the other of the seat support housing or bearing plate. Preferably, the adjustable chair further comprises a retaining plate, the bearing plate is sandwiched between the seat support housing and the retaining plate, in which the retaining plate is fixed to the seat support housing such that the retaining plate and the seat support housing slidingly and rotatably moveable relative to the bearing plate. Preferably, at least one bearing is provided between the retaining plate and the bearing plate. Preferably, the at least one bearing is provided on one of the retaining plate or the bearing plate, the at least one bearing engages with the other of the retaining plate or the bearing plate. Preferably, the bearing plate includes an aperture and the retaining plate includes an upward projection which extends through the aperture such that the sliding movement of the retaining plate and the seat support housing is limited by engagement between the upward projection and the aperture. Preferably, the bearing plate is fixed to the frame such that movement of the retaining plate moves the seat relative to the frame. Preferably, the upward projection extends through an aperture in the seat support housing, and an aperture in the bowl to slidingly fix the bowl to the retaining plate. Preferably, the seat is rotatably tiltable in an arc having a radius about a pivot point which is vertically spaced above a surface of the seat. Preferably, the bowl is partially spherical and has a bowl radius equal to the radius. Preferably, the bowl is partially spherical and has a bowl radius, the bowl is rotatably tiltable about a pivot point, in which the bowl radius is configured such that an upper surface of the seat is vertically spaced from the pivot point. Preferably, the upper surface of the seat has a seat centre point which moves in an arc about the pivot point during the rotatably tiltable movement of the seat. Preferably, the radius is configured such that the pivot point is positioned vertically above a third lumbar vertebra of a lumbar region of the seat occupant when the seat occupant is sitting on the seat, preferably above the third lumbar region. Preferably, the which the radius is configured such that the pivot point is positioned in a thoracic region of the spine of the seat occupant when the seat occupant is sitting on the seat, preferably proximate, more preferably above, a twelfth thoracic vertebra. Preferably, the seat is rotatably tiltable in an arc up to a maximum of tilt angle of degrees in any direction. Preferably, the seat is selectively rotatably movable and / or selectively rotatably tiltable and / or selectively slidable relative to the frame. Preferably, the adjustable chair further comprises an arm support, in which the seat is rotatably movable and / or rotatably tiltable and / or slidable relative to the arm support. According to another aspect of the present invention there is provided an adjustable chair comprising a seat and a frame, in which the seat is rotatably tiltable out of a lateral plane relative to the frame in any direction. According to another aspect of the present invention there is provided an adjustable chair comprising a seat for supporting a seat occupant, and a frame, in which the seat is slidingly moveable in any direction in a lateral plane relative to the frame, rotatably movable in the lateral plane relative to the frame, and rotatably tiltable in any direction relative to the frame, such that the seat can move relative to the frame in response to an adjustment of position of the seat occupant. According to another aspect of the present invention there is provided an adjustable chair comprising a seat to support a seat occupant and a frame, in which the seat is rotatably tiltable relative to the frame in an arc having a radius about a pivot point which is vertically spaced above a surface of the seat. Preferably, the radius is configured such that the pivot point is positioned vertically above a third lumbar vertebra of a lumbar region of the seat occupant when the seat occupant is sitting on the seat, preferably above the lumbar region. The invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 is a perspective view of an adjustable chair according to the present invention, Figure 2 is a side view of the adjustable chair of Figure 1, Figure 3 is an exploded perspective view of the adjustable chair of Figure 1, Figure 4 is an exploded perspective view of part of the adjustable chair of Figure 1, Figure 5 is a perspective view of part of the adjustable chair of Figure 1, Figure 6 is a sectional view (Section A-A Figure 12a) of part of the adjustable chair of Figure 1, Figure 7 is a perspective view of part of the adjustable chair of Figure 1, Figure 8 is a side view of part of the adjustable chair of Figure 1, Figure 9 is a perspective view of part of the adjustable chair of Figure 1, Figure 10 is a perspective view of part of the adjustable chair of Figure 1, Figures 11a to 11c are side views of the adjustable chair of Figure 1 in a central, forward and rearward position, Figures 12a to 12c are front views of the adjustable chair of Figure 1 in a central, left and right position, Figures 13a to 13c are side views of the adjustable chair of Figure 1 in a central untilted, left up tilted and right up tilted position, Figures 14a to 14c are front views of the adjustable chair of Figure 1 in a central untilted, left up tilted and right up tilted position, Figures 15a to 15c are side views of the adjustable chair of Figure 1 in a central untilted, front up tilted and rear up tilted position, Figures 16a to 16d are perspective views of the adjustable chair of Figure 1 rotating from a starting position (Figure 16a) through 360 degrees back to the starting position, Figure 17 is a perspective exploded view of an adjustable chair according to another embodiment of the present invention, Figure 18 is a perspective exploded view of part of an adjustable chair according to another embodiment of the present invention, Figure 19 is a perspective view of part of the adjustable chair of Figure 18, Figure 20 is a perspective exploded view of part of an adjustable chair according to another embodiment of the present invention, Figure 21 is a side view of part of adjustable chair of Figure 20, Figure 22 is a perspective exploded view of part of an adjustable chair according to another embodiment of the present invention, Figure 23 is a perspective view of part of the adjustable chair of Figure 22, Figure 24 is a perspective exploded view of part of an adjustable chair according to another embodiment of the present invention, Figure 25 is a perspective view of part of the adjustable chair of Figure 24, Figure 26 is a side view of part of the adjustable chair of Figure 1, Figure 27 is a side view of a spine, and Figure 28 is a side view of part of the adjustable chair of Figure 1 with the seat occupant and spine position shown. In Figures 1 to 16c, an adjustable chair 10 comprises a seat assembly 12 and a seat frame 14. The seat frame 14 comprises four legs 16 (only three of which are shown in Figures 1 to 3) to support the chair on a floor F, arm support 18, and a back support 20 which is integrated with the arm support 18. In alternative embodiments, the seat frame can have a different number of legs, or no legs, for example, the seat assembly 12 can be supported by a box-like structure which sits directly on the floor F. In Figure 3, the seat assembly 12 comprises a partially spherical hollow bowl 22, a seat 21, a bowl retainer 23, a seat support housing 24, a bearing plate 26 and a retaining plate 28. The seat 21 can be padded with a cushion, or unpadded. The hollow bowl 22 has a through aperture 13 and a lower surface 39. The hollow bowl 22 forms a lower sector of the circle defined by the radius R with a sector angle SA of 80 degrees (Figure 26). The bowl retainer 23 is also partially spherical and includes a through aperture 15. The bowl retainer 23 has the same spherical radius as the hollow bowl 22, but a smaller diameter such that it can locate inside the hollow bowl 22. In Figures 4 and 9, the seat support housing 24 includes an annular groove 25 into which a ball bearing housing 27 (not shown in Figure 9) locates. At least one bearing in the form of ball bearings 29 (not shown in Figure 9) are provided in the ball bearing housing 27 to enable the bowl 22 to move relative to the seat support housing 24 as will be described below. The seat support housing 24 further includes six recesses 31 into which at least one bearing in the form of upper slide bearings 33 locate and a through aperture 17 (Figure 10). In Figures 5 to 7, the bearing plate 26 is circular having a planar upper surface 30, a planar lower surface 32, a circular through aperture 34 at its centre, and a plurality of recesses 35 on the lower surface 32 through which screws 37 engage as will be described below. In Figures 4 and 6, the retaining plate 28 is circular having a planar upper surface 36 which includes through apertures 38 into which at least one bearing in the form of lower slide bearings 40 locate, and an upstanding threaded projection 42 which extends upwardly from a centre point CP of the upper surface 36 and through the apertures 13,15,17,34. A retaining nut 44 engages with the threaded projection 42 to secure the seat support 22 onto the retaining plate 28 as will be described below (Figures 5 and 6). The seat assembly 12 further includes a planar spacing plate 46 which is in the form of a circular ring having a central aperture 49 and includes an extended section 48. The plate 46 includes through apertures 50 through which screws 37 engage as will be described below. The seat assembly 12 includes a circular cover plate 52 which includes through apertures 54 through which screws 37 engage as will be described below. A pair of support struts 54 secure the chair arms 18 and back support 20 to the extended section 48 of the spacing plate 46 (Figures 1 and 2). The seat assembly 12 is assembled as follows: The bowl retainer 23, the hollow bowl, 22, the seat support housing 24, and the bearing plate 26 are positioned on the upstanding threaded projection 42 of the retaining plate 28 such that the upstanding threaded projection 42 extends through the apertures 13,15,17,34. The retaining nut 44 threads onto the upstanding threaded projection 42 to vertically secure the bowl retainer 23, the hollow bowl, 22, the seat support housing 24, and the bearing plate 26 to each other but allow relative movement in some directions as will be described below (Figures 4 to 6). After the retaining nut 44 has been threaded onto the upstanding threaded projection 42, the lower slide bearings 40 of the retaining plate 28 engage with the lower surface 32 of the bearing plate 26, and the upper slide bearings 33 of the seat support housing 24 engage with upper surface 30 of the bearing plate 26 to enable the seat support housing 24 and the retaining plate 28 to slide relative to the bearing plate 26 in a lateral plane L in any direction, including in an X direction, and in a Z direction which is perpendicular to the Z direction, and any direction within the lateral L plane between the X and Z directions. In other words, from left to right and right to left, and in and out of the plane of the paper when viewing Figure 6. In addition to the sliding movement of the seat support housing 24 and the retaining plate 28 relative to the bearing plate 26, the lower slide bearings 40 and the upper slide bearings enable the seat support housing 24 and the retaining plate 28 to rotate relative to the bearing plate 26 within the lateral plane L. After the retaining nut 44 has been threaded onto the upstanding threaded projection 42, the ball bearings 29 located in the annular groove 25 of the seat support housing 24 engage with the lower surface 39 of the hollow bowl 22 to enable the hollow bowl 22, and the seat 21 which is fixed thereto, to tilt in a direction T relative to the seat support housing 24 (Figure 8). In addition to the tilting movement of the hollow bowl 22 relative to the seat support housing 24, the ball bearings 29 enable the hollow bowl 22, and the seat 21 which is fixed thereto, to rotate relative to the seat support housing 24 in the lateral plane L. The circular cover plate 52 is secured to the planar spacing plate 46 and to the bearing plate 26 by inserting screws 37 through apertures 35,50,54 such that the retaining plate 28 locates inside the aperture 49 of the spacing plate 46 and is sandwiched between the cover plate 52 and the bearing plate 26. The circular cover plate 52 is then secured to the legs 16, or some other part of the frame 14 of the chair 10 using screws (not shown) or some other fixing means. It will therefore be understood that the seat 21 can slide, rotate and tilt relative to the frame 14 of the chair 10 due to the relative sliding and rotational movement between the retaining plate 28, which is fixed to the seat support housing 24, and the frame 14, and the relative tilting and rotational movement between the hollow bowl 22 and the seat support housing 24. The distance which the seat 21 can slide is limited by the movement of the retaining plate 28, specifically, the movement of the retaining plate 26 within the aperture 49 of the spacing plate 52, or in an alternative embodiment, the movement of the threaded projection 42 of the retaining plate 28 within the aperture 34 of the bearing plate 26. If the movement of the bearing plate 26 within the aperture 49 is less than the movement of the threaded projection 42 within the aperture 34 then the movement of the bearing plate 26 within the aperture 49 determines the distance the seat 21 can slide. Conversely, if the movement of the bearing plate 26 within the aperture 49 is greater than the movement of the threaded projection 42 within the aperture 34 then the movement of the threaded projection 42 within the aperture 34 determines the distance the seat 21 can slide. In Figures 11 to 17 the chair 10 is shown with the seat 21 having been moved in different directions under the action of a seat occupant (not shown) as follows: In Figures 11a, 12a, 13a, 14a, 15a and 16a to 16c, the chair 10 is shown with the seat 21 in a central and untilted position. In Figure 11b, the seat 21 has slidingly moved in the X-axis direction from the central position to a forward position (to the left when viewing Figure 11b). In Figure 11c, the seat 21 has slidingly moved from in the X-axis direction from the central position to a rearward position (to the right when viewing Figure 11c). In Figure 12b, the seat 21 has slidingly moved in the Z-axis direction from the central position to a left position (to the left when viewing Figure 12b). In Figure 12c, the seat 21 has slidingly moved in the Z-axis direction from the central position to a right position (to the right when viewing Figure 12c). It can be seen that the seat 21 slides within the lateral plane L when moving between the left and right positions and between the forward and rearward positions. It will be understood that the seat 21 can be moved fully or partially between the left and right positions and between the forward and rearward positions to enable the seat occupant to achieve a comfortable sitting position. It will be further understood that the seat 21 need not be slid sequentially in the X and Z axis directions, and can be moved simultaneously between the left and right positions and between the forward and rearward positions, to slide at an angle, for example, at 45 degrees. In Figures 13b and 14b, the seat 21 has tilted in the direction Tfrom the central position to a left up position. In Figures 13c and 14c, the seat 21 has tilted in the direction Tfrom the central position to a right up position. In Figure 15b, the seat 21 has tilted in the direction T from the central position to a front up position. In Figure 15c, the seat 21 has tilted in the direction T from the central position to a rear up position. It can be seen that the seat 21 has tilted up and down out of the lateral plane L in the Y axis direction when moving between the left up and right up positions and between the front up and rear up positions, as opposed to the above-described sliding and rotating movement which remains within the lateral plane L. It will be understood that the seat 21 can be moved fully or partially between the left up and right up positions and between the front up and rear up positions to enable the seat occupant to achieve a comfortable sitting position. It will be further understood that the seat 21 can be tilted simultaneously between the left up and right up positions and between the front up and rear up positions to enable the seat occupant to achieve a comfortable sitting position. In Figures 16a to 16d, the seat has rotated from a starting position (Figure 17a) through 360 degrees back to the starting position. The rotation can be achieved by relative rotation between the hollow bowl 22 and the seat support housing 24 or between the seat support housing 24 and the bearing plate 26. It can be seen in Figures 12 to 16 that the sliding, tilting and rotating movement of the seat 21 is relative to the frame 14 and therefore the arm support 18 and back support 20 to which the frame 14 is fixed. Such functionality is beneficial in an environment where the chair 10 is close to another piece of furniture, for example, a desk or table (not shown), and the seat 21 can tilt, slide and rotate relative to the furniture, but without requiring the frame 14 of the chair 10 to move. In Figure 26, the bowl 22 has a bowl radius R and a centre pivot point P about which the bowl 22 tilts. The seat 21, which is fixed to the bowl 22, has an upper surface S upon which the occupant sits. It can be seen that the radius R is sufficiently large such that the upper surface S is vertically spaced from the pivot point P. The seat 21 has a seat centre point C on the upper surface S moves in an arc about the pivot point P, during the rotatably tiltable movement of the seat 21 in the direction T. It will be clear that the centre point C and the pivot point P both move relative to the arm support 16, back support 20 and legs 16 during the tiltable movement of the seat 21. In Figure 14c, the tilt angle TA is 30 degrees. Typically this is the maximum tilt angle TA in any of the tilting directions. In Figure 17, an alternative chair 110 is shown which is identical to the chair 10 except as described below. The chair 110 comprises a seat frame 114, identical to seat frame 14, and a seat assembly 112. The seat assembly 112 includes at least one bearing in the form of a plurality of slide bearings 129 which locate inside corresponding recesses 125 in the seat support housing 124 to enable rotating and tilting movement of the hollow bowl 122. In Figures 18 and 19, a seat assembly 212 is identical to the seat assembly 12,112 except as described below. The seat assembly 212 includes at least one bearing in the form of plurality of wedge bearings 229 which are fixed to a seat support plate 224. The wedge bearings 229 are shaped and inclined relative to a hollow bowl 222 such that the hollow bowl 222 can rotate and tilt relative to the seat support plate 224. The wedge bearing 229 and hollow bowl 222 materials are selected so as to provide the correct amount of friction therebetween. The seat support plate 224 is fixed to four steel support blocks 260 using bolts (not shown). The steel support blocks 260 include internal bearings 262 into which first rods 264 are housed to enable the steel support blocks 260 to slidingly move in the X direction within the lateral plane L. A T-shaped steel support block 266 is located on the end of each first rod 264. Each T-shaped steel support block 266 includes an internal bearing 269 into which second rods 268 are housed to enable the T-shaped steel support blocks 266 to slidingly move in the Z direction within the lateral plane L. Each end of the second rods 268 is secured to an upstanding portion 270 of a support frame 272. The support frame 272 is secured to the frame, identical to frame 14,114, of the seat (neither of which are shown). Operation of the seat assembly 212 is identical to seat assembly 12,112 except that the tilting and rotating movement is enabled by the interaction between the wedge bearings 229 and the hollow bowl 222, and the sliding movement is enabled by movement of respective support blocks 260,266 on rods 264,268. It will be understood the unlike the sliding movement of seat assembly 12,112 in any direction, that is any angle, in the lateral plane L, the seat assembly 212, or more specifically, the support plate 224, requires incremental movement in the X and Z directions to achieve angular movement. In Figures 20 and 21, a seat assembly 312 is identical to the seat assembly 212 except that the seat supporting housing 324 has a different shape to accommodate three inclined bearings 329 rather than the six bearings 229 of seat assembly 212, and each of the inclined bearings 329 includes a recess 341 into which a slide bearing 343 locates. Operation of the seat assembly 312 is identical to seat assembly 212 except that the tilting and rotating movement of the bowl 322 is enabled by the interaction between the slide bearings 343 and the hollow bowl 322. In Figures 22 and 23, a seat assembly 412 is identical to the seat assembly 12 except as described below. The hollow bowl 422 tilts and rotates relative to the seat support housing 424 in the same way as described in relation to seat assembly 12. The seat assembly 412 includes four upper blocks 466 onto which the seat support housing 424 is fixed. Two of the upper blocks 466 are each located on two parallel spaced upper rails 468. The blocks 466 include linear slide bearings 469 which enable the seat support housing 424 to slidingly move in the Z direction within the lateral plane L. Each of the upper rails 468 are fixed to an upper support plate 480. The seat assembly 412 includes four lower blocks 482, identical to upper support blocks 466, onto which the upper support plate 480 is secured. Two of the lower blocks 482 are each located on two parallel spaced lower rails 484, identical to upper support rails 468, and fixed to a lower support plate 486. The lower blocks 482 also include linear slide bearings 469 which enable the upper support plate 480 to slidingly move in the X direction within the lateral plane L relative to the lower support plate 486. The lower support plate 486 is secured to the frame, identical to frame 14, of the seat (neither of which are shown). The tilting and rotating movement of the seat assembly 412 is identical to that described in relation to the seat assembly 12. The sliding movement of the seat assembly 412 is similar to that described in relation to the seat assembly 212, except that the seat support housing 424 slidingly moves in the Z direction due to being slidingly movable on the upper support plate 480, and the seat support housing 424 slidingly moves in the X direction due to the upper support plate 480 being slidingly movable on the lower support plate 486. In Figures 24 and 25, an alternative seat assembly 512 is shown which includes a combination of the features of the seat assemblies 12,212,412. The hollow bowl 522 tilts and rotates relative to the seat support housing 524 in the same way as described in relation to seat assembly 412. The seat assembly 512 includes a seat support housing plate 590 to which the seat support housing 524 is fixed. Two parallel spaced upper rails 568, each with two upper blocks 566 including linear slide bearings 569 located thereon, are fixed to an upper support plate 580. The upper rails 568, upper blocks 566 and linear slide bearings 569 are identical to those of seat assembly 412. The upper blocks 566 are also fixed to the seat support housing 590 which enables the seat support housing plate 590 to slidingly move on upper rails 568 in the Z direction within the lateral plane L. Two parallel spaced lower rails 564, each with two lower blocks 566 including linear slide bearings 569 through which the lower rails pass through, are fixed to a support frame 572 in the same way as described in relation to the seat assembly 212. The upper blocks 566 are also fixed to the upper support plate 580 which enables the seat support housing plate 590 to slidingly move in the X direction within the lateral plane L relative to the support frame 572. The sliding movement of the seat assembly 512 is similar to seat assembly 412, except that the seat support housing 524 slidingly moves in the Z direction due to being slidingly movable on the upper support plate 580, and the seat support housing 524 slidingly moves in the X direction due to the upper support plate 580 being slidingly movable on the support frame 572. In the above described seat assemblies 12-512, the seat 21 can slide, rotate and tilt relative to the frame 14 simultaneously or independently according to how the seat occupant manipulates the seat 21. In alternative seat assemblies, a mechanism, for example a latch (not shown) can be added to allow the occupant to selectively disable one or all of the sliding, rotating or tilting movement, thereby eliminating the possibility of the occupant inadvertently inducing an undesired movement. For example, the seat occupant may desire rotating and sliding movement only, and disable the tilting function. Alternatively, the seat occupant may disable the tilting, rotating and sliding movement such that the chair functions as a static chair without any adjustment. Whilst, in the above alternative embodiment the occupant can selectively disable one or all of the sliding, rotating or tilting movement in certain circumstances, the ability of the seat of the chair to be adjusted by sliding, rotating and tilting in any direction in response to the seat occupant adjusting his or her body position during use enables the seat to freely move to the seat occupant’s adjusted position and provide the seat occupant with a more comfortable and supported position when compared to a seat without such adjustment. In alternative embodiments, instead of being able to disable certain movements, alternative seat assemblies can be designed without tilting, rotating or sliding movement. For example, seat assemblies 12-512 need not have the tilting function, with the bowl 22 fixed to the seat support housing 24 such that the bowl 22 can still rotate and slide, but cannot tilt. In further alternative embodiments, seat assemblies 12-512 need not have the sliding function, for example bowl 22 can be fixed to the cover plate 52 such that the bowl 22 can still tilt and rotate, but cannot slide. In further alternative embodiments, seat assemblies 212-512 need not have the sliding function in both the X and Z direction, for example, in seat assembly 412 (Figures 22 and 23), the upper rails 468 and upper support plate 480 can be removed, and the seat support housing 424 can be directly fixed to the lower blocks 482 such that the bowl 422 can only slide in the X direction. Alternatively, the lower blocks 482 and lower support plate 486 can be removed, with the upper support plate 480 fixed directly to the seat frame such that the bowl 422 can only slide in the Z direction. In the above described seat assemblies 12-512, the seat 21 can slide, rotate and tilt relative to the frame 14 due to the inclusion of bearings between moving and contacting components. In alternative embodiments, the tilting and rotating movement can be achieved without the use of bearings by careful selection of materials and profiles of those components. For example, in seat assembly 12, bearings 29 can be removed, and the bowl 22 and seat support housing 24 profiled, for example, partially spherical, such that those components 22,24 can nest within each other and therefore tilt and rotate relative to each other, and materials selected to provide the appropriate amount of friction between those components 22,24. Similarly, in seat assembly 12, bearings 33 and / or 40 can be removed by using planar contacting surfaces for contacting components, i.e. cover 52, retaining plate 28, bearing plate 26 and seat supporting housing 24, such that those components 52,28,26,24 can slide and rotate relative to each other, and materials selected to provide the appropriate amount of friction between those components. The Applicant has discovered that by providing a seat with sliding, tilting and rotating adjustability, the seat occupant SO can adjust his or her position to obtain a more comfortable sitting position. In particular, the Applicant has recognised the importance of being able to adjust the position of the seat occupant’s pelvis and at the same time maintain support of the spine SP in the upper body region (cervical and thoracic), thereby avoiding fatiguing the spine SP. More specifically, and with reference to Figures 26 to 28, it can be seen that the pivot point P about which the seat 21 tilts, is vertically above the surface S of the seat 21, and vertically above a first lumbar vertebra L1 of the lumbar region LR, in the thoracic region of the spine SP of the seat occupant SO. The pivot point P is spaced from the first lumbar vertebra L1 by a vertical distance VS. The Applicant has discovered that the radius R of the bowl 22, and therefore the radius R at which the bowl 22 tilts can be adjusted in length to position the pivot point P at a certain location, or more importantly, above a certain location of the seat occupant’s spine SP. At the same time, increasing the radius R reduces the speed, and therefore increases the stability, of the tilting movement of the seat 21 when being moved by the seat occupant SO. In the example of Figures 1 and 29, a radius R of 330mm and a seat occupant SO having a height of approximately 1.83m, positions the pivot point P at a twelfth thoracic vertebra T12 and provides a stable seat 21. In another example, a radius R of 298mm and a seat occupant SO having a height of approximately 1.83m, positions the pivot point P at a third lumbar vertebra L3 of the lumbar region LR and provides a stable seat. Joint problems typically occur at spinal joints L3 / L4, L4 / L5 and L5 / S1, and therefore positioning the pivot point P at position L3 reduces the stress on spinal joints below the level of L3 and positioning the pivot point P at T12 reduces the stress on spinal joints below the level of T12, that is all of the lumber region LR, but at the same time, the arm supports 18 and back support 20 provide support of the thoracic and cervical regions of the spine SP. It will be understood that knowing the height of the seat occupant SO, and the desired position of the pivot point P relative to the spinal joints, it is possible to set the length of the radius R accordingly. Typically the radius will be between 280mm and 350mm.

Claims

1. An adjustable chair (10) comprising a seat (21) to support a seat occupant (SO) and a frame (14), the seat (21) is slidingly moveable in a lateral plane (L) relative to the frame (14), in which the seat (21) is rotatably tiltable in an arc (T) having a radius (R) about a pivot point (P) which is vertically spaced above a surface (S) of the seat (21).

2. An adjustable chair (10) according to claim 1 in which the seat (21) is slidingly moveable in the lateral plane (L) in at least two directions, preferably in at least two directions (X,Z) that are perpendicular to each other.

3. An adjustable chair (10) according to claim 1 or 2 in which the seat (21) is slidingly moveable in the lateral plane (L) in any direction.

4. An adjustable chair (10) according to any preceding claim in which the seat (21) is rotatably movable in the lateral plane (L) relative to the frame (14).

5. An adjustable chair (10) according to any preceding claim in which the seat (21) is rotatably tiltable relative to the frame (14) out of the lateral plane (L).

6. An adjustable chair (10) according to claim 5 in which the seat (21) is rotatably tiltable relative to the frame (14) in any direction.

7. An adjustable chair (10) according to claim 5 or 6 further comprising a seat support housing (24), in which the seat (21) is rotatably movable in, and rotatably tiltable out, of the lateral plane (L) relative to the seat support housing (24), the seat support housing (24) is slidingly moveable in a lateral plane (L) relative to the frame (14).

8. An adjustable chair (10) according to claim 7 further comprising a bowl (22), in which the seat (21) is fixed to the bowl (22), the bowl (22) is rotatably movable in, and rotatably tiltable out, of the lateral plane (L) relative to the seat support housing (24).07 01 259. An adjustable chair (10) according to claim 8 further comprising at least one bearing (29) between the seat support housing (24) and the bowl (22).

10. An adjustable chair (10) according to claim 9 in which the at least one bearing (29) is provided on one of the seat support housing (24) or the bowl (22), the at least one bearing engages with the other of the seat support housing (24) or the bowl (22).11 .An adjustable chair (10) according to any one of claims 7 to 10 further comprising a bearing plate (26) which is fixed to the frame (14), in which the seat support housing (24) is slidingly and rotatably moveable relative to the bearing plate (26).

12. An adjustable chair (10) according to claim 11 further comprising at least one bearing (33) between the seat support housing (24) and the bearing plate (26).

13. An adjustable chair (10) according to claim 12 in which the at least one bearing (33) is provided on one of the seat support housing (24) or the bearing plate (26), the at least one bearing (33) engages with the other of the seat support housing (24) or bearing plate (26).

14. An adjustable chair (10) according to any one of claims 11 to 13 further comprising a retaining plate (28), the bearing plate (26) is sandwiched between the seat support housing (24) and the retaining plate (28), in which the retaining plate (28) is fixed to the seat support housing (24) such that the retaining plate (28) and the seat support housing (24) are slidingly and rotatably moveable relative to the bearing plate (26).

15. An adjustable chair (10) according to claim 14 further comprising at least one bearing (33) between the retaining plate (28) and the bearing plate (26).

16. An adjustable chair (10) according to claim 14 or 15 in which the bearing plate (26) includes an aperture (34) and the retaining plate (28) includes an upward projection (42) which extends through the aperture (34) such that the sliding movement of the07 01 25retaining plate (28) and the seat support housing (24) is limited by engagement between the upward projection (42) and the aperture (34).

17. An adjustable chair (10) according to claim 16 further comprising at least one bearing (40) between the retaining plate (28) and the bearing plate (26).

18. An adjustable chair (10) according to claim 17 in which the at least one bearing (40) is provided on one of the retaining plate (28) or the bearing plate (26), the at least one bearing (40) engages with the other of the retaining plate (28) or the bearing plate (26).

19. An adjustable chair (10) according to any one of claims 11 to 18 in which the bearing plate (26) is fixed to the frame (14).

20. An adjustable chair (10) according to any one of claims 16 to 19 in which the upward projection (42) extends through an aperture (17) in the seat support housing (24), and an aperture (13) in the bowl (22) to slidingly fix the bowl (22) to the retaining plate (28).

21. An adjustable chair (10) according to claim 20 when dependent on any one of claims 8 to 20, in which the bowl (22) is partially spherical and has a bowl radius equal to the radius (R).

22. An adjustable chair (10) according to claim 21 in which the upper surface (S) of the seat (21) has a seat centre point (C) which moves in an arc about the pivot point (P), during the rotatably tiltable movement of the seat (21).

23. An adjustable chair (10) according to any one of claims 20 to 22 in which the radius (R) is configured such that the pivot point (P) is positioned vertically above a third lumbar vertebra (L3) of a lumbar region (LR) of the seat occupant (SO) when the seat occupant (SO) is sitting on the seat (21), preferably above a third lumbar region (LR).07 01 2524. An adjustable chair (10) according to claim 23 which the radius (R) is configured such that the pivot point (P) is positioned in a thoracic region of the spine (SP) of the seat occupant (SO) when the seat occupant (SO) is sitting on the seat (21), preferably proximate, more preferably above, a twelfth thoracic vertebra (T12).

25. An adjustable chair (10) according to claim any one of claims 20 to 25 in which the seat (21) is rotatably tiltable in an arc (T) up to a maximum of tilt angle (TA) of 30 degrees in any direction.

26. An adjustable chair (10) according to any preceding claim in which the seat (21) defines a sector angle (SA) of less than 90 degrees.

27. An adjustable chair (10) according to any preceding claim in which the seat (21) is selectively rotatably movable and / or selectively rotatably tiltable and / or selectively slidable relative to the frame (14).

28. An adjustable chair (10) according to any preceding claim further comprising an arm support (18), in which the seat (21) is rotatably movable and / or rotatably tiltable and / or slidable relative to the arm support (18).

29. An adjustable chair (10) according to any preceding claim in which the radius (R) is configured such that the pivot point (P) is positioned vertically above a third lumbar vertebra (L3) of a lumbar region (LR) of the seat occupant (SO) when the seat occupant (SO) is sitting on the seat (21), preferably above a lumbar region (LR).Application No: GB2405809.1 Examiner: Hari FletcherClaims searched: 1-29 &31Date of search: 18 October 2024Patents Act 1977: Search Report under Section 17Documents considered to be relevant:Category Relevant to claims Identity of document and passage or figure of particular relevance X 1,4-6,21, 27-29 &31 KR 20140142072 A (JUNG DAE HOON) See figures. X 1, 4-6, 21, 27-29 & 31 US 2012 / 0256459 Al (NILSSON et al.) See figures. X 1,4-6,21, 27-29 &31 US 10925401 Bl (KASSNER) See figures. X 1, 4-6, 21, 27-29 & 31 US 2011 / 0304187 Al (ROSS) See figures. X 1, 4-6, 21, 27-29 & 31 US 2020 / 0000234 Al (VANMAASTRICHT et al.) See figures.Categories:X Document indicating lack of novelty or inventive step A Document indicating technological background and / or state of the art. Y Document indicating lack of inventive step if P Document published on or after the declared priority date but combined with one or more other documents of same category. before the filing date of this invention. & Member of the same patent family E Patent document published on or after, but with priority date earlier than, the filing date of this application.Field of Search:www.gov.uk / ipoInternational Classification:Subclass Subgroup Valid From A47C 0001 / 023 01 / 01 / 2006 A47C 0003 / 18 01 / 01 / 2006 A47C 0007 / 02 01 / 01 / 2006 A47C 0007 / 14 01 / 01 / 2006 A47C 0009 / 00 01 / 01 / 2006www.gov.uk / ipo

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