Patent Publication Number: US-2022232982-A1

Title: Adjustable chair

Description:
BACKGROUND OF THE INVENTION 
     Conventional chairs are designed to fit and support a user&#39;s body. Some are adjustable with respect to arm rest height or the incline of the back support. Some include adjustable lumbar supports for optimal support of the user&#39;s spine. 
     However, these adjustability options are not sufficient for a chair for use by users of multiple heights and body shapes. For example, a school chair may be used by a schoolchild over many months, during which time the schoolchild will be growing in height and weight. Gradually, they will outgrow the chair which leads to discomfort, poor posture and potentially back pain. Alternatively, a school chair may be used by more than one child of differing heights and body shapes on a regular basis. However, without sufficient adjustability the chair will not be suitable for all. 
     As children grow, their leg length increases. Thus, an increase in their lower leg length will require a chair of increasing height to ensure that the child&#39;s foot can be flat on the floor whilst the underside of their leg makes contact across the seat base. This means that some of the load is supported through the feet whilst the underside of the leg has even pressure against the seat base. This seated position tends to result in an approximate 90° bend at the knee when the child is properly seated and supported by the chair. Further, an increase in their upper leg length will require a chair with a deeper seat base to ensure that their upper leg is sufficiently supported in a direction towards the knee. To keep measuring children throughout their time at school and provide a new chair of suitable dimensions to accommodate their growth on a regular basis is time-consuming and expensive. 
     There is therefore a need for a chair that is suitably adjustable to accommodate the changing leg length of the child over time. 
     SUMMARY OF THE INVENTION 
     The present invention seeks to address the problems of the prior art. Aspects of the present invention are set out in the attached claims. 
     According to a first aspect of the present invention, there is provided an adjustable chair comprising: a seat base defining a seating surface portion for receiving a user thereon in use, the seat base comprising an integral seat back engagement portion for engaging with a portion of a seat back, a seat front portion opposing the seat back engagement portion, a first seat side portion and a second seat side portion opposing the first seat side portion, each of the first and second seat side portions located between the seat back engagement portion and the seat front portion and extending substantially transverse to the seat surface portion; and a seat back having a seat base engagement portion dimensioned to slidably engage with the seat back engagement portion to form a seat back adjustment mechanism, wherein the seat back adjustment mechanism is located adjacent at least one of the first and second seat side portions and wherein the seat back adjustment mechanism is movable between a first locked configuration in which the seat back and seat base are fixed relative to one another and the seating surface portion has a fixed surface area, and a second released configuration in which the seat back is slidable relative to the seat base to vary the surface area of the seating surface portion. 
     Thus, the depth of the seat base can be varied by moving the seat back relative to the seat base to adjust the seating area available for a user to sit on, in use. Thus, for a user of lesser height, the seating surface portion and thus seat depth can be adjusted to bring the seat back closer to the front of the seat base to allow the user to sit comfortably with their back against the seat back. 
     Having the seat back engagement portion integral with the seat base provides the advantage of simplification of design, with associated cost savings, and increased ease of assembly. Further, the integral nature of the seat back engagement portion and seat base provide the chair with greater structural integrity and strength. 
     The location of the seat back adjustment mechanism is important. The seat back adjustment mechanism is provided on the outside edge of the seat base i.e. adjacent at least one of the first and second seat side portions, rather than underneath the seat base. This increases the visibility of the seat back adjustment mechanism. 
     Further, the seat back adjustment mechanism is provided on the outside edge of the seat base, rather than on the upper surface of the edge of the seat base, to avoid the adjustment mechanism collecting dust and potentially having objects inserted in it e.g. chewing gum and the like, which could potentially damage the mechanism. Further, if provided on the upper surface of the edge of the seat base, a user sitting on the chair could inadvertently apply downward force on the mechanism, thereby releasing the latch from the recess and accidentally allowing the seat back to slide relative to the seat base. 
     In one embodiment, the seat back adjustment mechanism comprises: a first engagement portion for engagement with a latch; and a latch pivotable about a pivot point, the latch comprising a second engagement portion for engagement with the first engagement portion, wherein the latch is pivotable between the first locked configuration in which the first and second engagement portions are in rigid engagement with one another and the seat back and seat base are fixed relative to one another, and the second released configuration in which the first and second engagement portions are in slidable engagement with one another and the seat back is slidable relative to the seat base. 
     In one embodiment, the first engagement portion comprises a plurality of recesses, each recess being dimensioned to receive at least a portion of the second engagement portion therein. 
     Preferably, the latch is biased towards the first engagement portion. 
     The latch may be biased towards the first engagement portion under force from a coil spring engaged with the latch and arranged between the latch pivot point and the second engagement portion. 
     Preferably, the latch is pivotable between the first locked configuration and the second released configuration on application of force to a portion of the latch located distal to the second engagement portion. 
     In one embodiment, the seat base engagement portion comprises the first engagement portion and the seat back engagement portion comprises the latch. 
     Preferably, the seat back is provided as a single-piece moulding. This provides strength to the chair and stability for the slidable movement of the back rest relative to the seat base. 
     More preferably, the seat back is provided with a plurality of apertures which act as air-holes to provide ventilation to the back of a user when sitting in the chair. The apertures further allow controlled flexing of the seat back by a user when sitting in the chair, thus increasing the comfort of a user, during use. 
     In one embodiment, the adjustable chair comprises a second seat back adjustment mechanism such that a seat back adjustment mechanism is located adjacent each of the first and second seat side portions, both seat back adjustment mechanisms must be moved from the first locked configuration to the second released configuration to allow the seat back to be slidable relative to the seat base. 
     In a further embodiment, the adjustable chair further comprises a footrest extending away from the seat base, the footrest comprising: a first footrest portion extending away from the seat base, the first footrest portion comprising a footrest engagement portion for engagement with a second footrest portion; and a second footrest portion comprising a footplate for receiving the feet of a user in use, the second footrest portion having a first footrest engagement portion dimensioned to slidably engage with the footrest engagement portion to form a footrest adjustment mechanism, and the footplate being arranged distal to the first footrest engagement portion, wherein the footrest adjustment mechanism is moveable between a footrest locked configuration in which the first and second footrest portions are in fixed engagement with one another and the footplate is at a fixed distance from the seat base, and a footrest released configuration in which the first and second footrest portions are slidable relative to one another to adjust the distance between the footplate and the seat base. 
     In one embodiment, the footrest adjustment mechanism comprises: a first engagement portion for engagement with a latch; and a latch pivotable above a fixed pivot point, the latch comprising a second engagement portion for engagement with the first engagement portion, wherein the latch is pivotable between the footrest locked configuration and the footrest released configuration. 
     In one embodiment, the footrest adjustment mechanism first engagement portion comprises a plurality of recesses, each recess being dimensioned to receive at least a portion of the footrest adjustment mechanism second engagement portion. 
     Preferably, the footrest adjustment mechanism latch is biased towards the plurality of recesses of the footrest adjustment mechanism. 
     The footrest adjustment mechanism latch may be biased towards the plurality of recesses of the footrest adjustment mechanism under force from a second coil spring engaged with said latch and arranged between the pivot point of said latch and the footrest adjustment mechanism latch recess engagement portion. 
     Preferably, the footrest adjustment mechanism latch is pivotable between the footrest locked configuration and the footrest released configuration on application of force to a portion of the said latch located distal to the latch recess engagement portion. 
     In one embodiment, the first footrest portion comprises the first engagement portion and the second footrest portion comprise the footrest adjustment mechanism latch. 
     In one embodiment, the first footrest portion is pivotally engaged with the seat base. 
     Preferably, the footrest is pivotable from the vertical position to a position beneath the seat base. This allows the user to move the footrest backwards slightly when standing in position to lower themselves into the chair. As the user&#39;s feet move slightly beneath the seat base in the normal manner, the footrest will be swung away from the vertical in a direction towards the seat base by the lower legs of the user as their feet are moved under the chair. This movement of the footrest is particularly beneficial when a user slides the chair forwards, for example, when sliding the chair under a desk. The user&#39;s feet will inevitably end up beneath the chair as they are sliding it, and the benefit of the footrest swinging away from the vertical is extremely beneficial in such a situation. 
     In one embodiment, the footrest is pivotable from the vertical position in a direction away from the seat base. 
     An adjustable chair as claimed in claim  15 , wherein the seat base defines a first plane and the footrest pivots in a second plane, wherein the first and second planes are transverse to one another. 
     The footrest pivot position is carefully selected so that it is at approximately the same height as the natural pivot point of the user&#39;s knee joint. Thus, when swinging, the footplate remains at approximately the same distance from the knee of the user. This also allows an increased level of upward swing movement of the footrest. 
     A further advantage of a swinging footrest is the ability of a user e.g. a child, to move the footrest (in a fidgeting fashion) while resting their feet on it during use of the chair. Studies have demonstrated that this leg movement in children can assist with concentration during learning events and assists with the dissipation of excess energy, whilst remaining in the seated position. 
     A further advantage of the footrest feature is safety related. Whilst using a chair with a footrest that is adjustable to accommodate the leg-length of the user, the user is less likely to attempt to put their feet on the floor during use of the chair and try to push backwards such that the chair tips on the rear legs. Excess tipping can destabilise the chair, resulting in the child being injured as they fall backwards with the chair. 
     A further advantage of the chair of the present invention is that the height of the chair is fixed, and it is the backrest and/or footrest that are adjustable in dependence upon the dimensions of the user. Thus, in a classroom setting, every child will be sitting at the same height on the base. Thus, no matter the height of an individual child, they will be at the same level as their peers of various different heights to themselves. Further, this means that each child will be seated at an appropriate height to use fixed height desks and tables. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view from one side of an embodiment of a chair in accordance with the present invention; 
         FIG. 2  is a front view of the chair of  FIG. 1 ; 
         FIG. 3  is a view from the other side of the chair of  FIG. 1 ; 
         FIG. 4  is a rear view of the chair of  FIG. 11 ; 
         FIG. 5  is a perspective view from behind of the chair of  FIG. 1 ; 
         FIG. 6  is a perspective view from the front of the chair of  FIG. 1 ; 
         FIG. 7  is a view from above of the chair of  FIG. 1 ; 
         FIG. 8  is a view from below of the chair of  FIG. 1 ; 
         FIG. 9  is a front view of the chair back of the chair of  FIG. 1 ; 
         FIG. 10  is a perspective view of the chair back of  FIG. 9 ; 
         FIG. 11  is a front view of the footrest of the chair of  FIG. 1  in an extended configuration; 
         FIG. 12  is a perspective view of the footrest of  FIG. 11 ; 
         FIG. 13  is a front view of the footrest of the chair of  FIG. 1  in a retracted configuration; 
         FIG. 14  is a perspective view of the footrest of  FIG. 13 ; 
         FIG. 15  is a perspective view of the chair of  FIG. 1 , showing the foot rest in an extended configuration and the back rest in an extended configuration; 
         FIG. 16  is a perspective view of the chair of  FIG. 1 , showing the footrest in a retracted configuration and the chair back in a retracted configuration; 
         FIG. 17  is a side view of the chair of  FIG. 15 ; 
         FIG. 18  is a side view of the chair of  FIG. 16 : 
         FIG. 19  is a front view of the chair of  FIG. 15 ; 
         FIG. 20  is a front view of the chair of  FIG. 16 ; 
         FIG. 21  is a side view of the chair of  FIG. 1 , showing the footrest in an extended configuration and pivoted outwards from the chair base; 
         FIG. 22  is a side of the chair of  FIG. 1 , showing the footrest in an extended configuration and pivoted inwards under the chair base; 
         FIG. 23  is a perspective view of the chair of  FIG. 22 ; 
         FIG. 24  is a perspective view of the chair of  FIG. 23 ; 
         FIG. 25  is a block illustration of the front view of the chair of  FIG. 1 ; 
         FIG. 26  is a section B-B through the chair of  FIG. 25 ; 
         FIG. 27  is a section A-A through the chair of  FIG. 25 ; 
         FIG. 28  is an enlarged view of the detail D of  FIG. 26 ; 
         FIG. 29  is an enlarged view of the detail C of  FIG. 27 ; 
         FIG. 30  is a side view of a user sitting in an embodiment of a chair in accordance with the present invention with the footrest swung forward (the adjustable backrest is not shown); and 
         FIG. 31  is a side view of the user and chair of  FIG. 30  with the footrest swung under the seat base. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Throughout the figures, the same figures references have been used to refer to the same features of the invention. 
     The figures show an adjustable chair  10  comprising a seat base  12  adapted to receive a user thereon in use and defining an exposed seating surface area  14  for receiving a user thereon in use. Seat base  12  is substantially planar. Although shown as a one-piece moulding, it will be appreciated that the seating surface area  14  may padded for the comfort of the user. In the embodiment shown, the front edge  40  of seat base  12  is shown as curved, in a contour known in the industry as a ‘waterfall’ front edge. This assists with the comfort of a user and the back of a user&#39;s knees are supported by a smooth curved surface. 
     The chair  10  further comprises a seat back  16 . Seat back  16  has an elongate U-shaped seat base engagement portion  18  and seat base  12  has a corresponding seat back engagement portion  20  which is an elongate tubular structure and is dimensioned to fit within the U-shaped seat base engagement portion and is in slidable engagement with seat back engagement portion  20  to form an adjustment mechanism  24 . 
     Seat back adjustment mechanism  24  is composed of the seat base engagement portion  18  and the seat back engagement portion  20 . 
     Seat back engagement portion  20  is provided with a plurality of recesses  26  and seat base engagement portion  18  is provided with a latch mechanism. 
     The latch mechanism comprises a latch  28  which is pivotably about fixed pivot point  30  and a coil spring  32 . Latch  28  comprises a coil spring engagement portion  34  which is engaged with coil spring  32 . Latch  28  further comprises a recess engagement portion  36  located on the same side of the pivot point  30  as the coil spring  32 . Recess engagement portion  36  is located adjacent recesses  26  and is dimensioned to be received within one of the plurality of recesses. Coil spring  32  biases the latch  28  towards the recesses  26  and holds the latch recess engagement portion  36  within a selected recess  26 , in use. 
     The button portion  38  of latch  28  distal to the recess engagement portion  36  comprises a convex surface to allow easy engagement by a user during adjustment of the seat back adjustment mechanism. 
     Latch  28  is provided such that the button portion  38  is presented on the outward edge of the seat base  12 . This allows ease of access for a user, whilst avoiding the disadvantages of conventional chairs where adjustment mechanisms are provided on the upper surface of the edge of the seat base i.e. foiling of the adjustment mechanism by dust and other debris. Further, the potential danger of accidental release of the adjustment mechanism by inadvertently leaning on it, is avoided. 
     Thus, in use, the recess engagement portion  36  of latch  28  is biased by coil spring  32  into a recess  26 , thus preventing the seat base engagement portion  18  and seat back engagement portion  20  from being slidable relative to one another. It is to be appreciated that, when the backrest is pushed backwards, once engaged, any pressure applied to the latch mechanism (apart from pressure applied to button portion  38 ) will not encourage the latch  28  to be released from the recess  26 . Instead, the recess engagement portion  36  will be more firmly pushed into engagement with the recess  26 . 
     On application of force by a user to the button portion  38  of latch  28 , latch  28  is pivoted about the fixed pivot point  30  to compress coil spring  32  and move coil spring engagement portion  36  of latch  28  out of engagement with recess  26 . Once the coil spring engagement portion  36  and recess  26  are disengaged, seat base engagement portion  18  and seat back engagement portion  20  can be slidably moved relative to one another thus moving the seat back relative to the seat base and altering the exposed seating surface are  14 . 
     Seat base  12  has a front edge  40  and a rear edge  42 . Movement of the seat back  16  in a direction from the rear edge  42  of seat base  12  towards the front edge  40  of seat base  12  will reduce the exposed seat surface area  14 . Subsequent return movement of the seat back  16  toward the rear edge  42  of seat base  12  will increase the exposed seating surface area  14  available for a user to sit on. 
     After slidable movement of seat back  16  relative to seat base  12 , release of force on button portion  38  of latch  28  will allow the latch  28  to pivot back about fixed pivot point  30  under the biasing influence of coil spring  32  as it decompresses, thus bringing recess engagement portion  36  of latch  28  back into contact with the seat back engagement portion so that the recess engagement portion  36  of latch  28  may once again engage with one of the recesses  26 . The amount of adjustment made to the seating surface area  14  depends on the amount of movement of seat base engagement portion  18  relative to seat back engagement portion. The plurality of recesses is provided at staggered intervals to permit a plurality of points of adjustment and therefore a corresponding number of different sizes of seating surface area  14  that may be achieved using the same adjustable chair. Typically, the range of adjustment will be sufficient to accommodate the anticipated range of heights of potential users of the chair. Ideally, the plurality of recesses will be evenly spaced and sufficient in number to cover the full range of adjustment and allow incremental adjustments to be made to suit the requirements of a user. 
     Thus, adjustment of the position of the seat back  16  relative to the seat base  12  will vary the seating surface area  14  and, in particular, will vary the distance between the seat back  16  and the front edge  40  of seat base  12 . This allows the same adjustable chair to be used by users of different heights. More specifically, the chair can be adjusted to suit users where the distance between the hips and knees of each user varies. This is particularly important where the chair is to be used by an individual child who will grow in height over time or where the chair is to be used by multiple individuals of different heights and/or femur lengths. 
     Seat back  16  is provided as a single-piece moulding and is provided with apertures  17 . The single-piece moulding provided stability to the seat back adjustment mechanism, whilst apertures  17  act as ventilation to allow air to circulate around the back of the user to increase comfort levels during use. Further, apertures  17  allow a controlled level of flex within the seat back  16 , thus further assisting with the comfort of the user when sitting in the chair  10 .The chair  10  is further provided with a footrest  22  extending from the front edge  40  of seat base  12 . The footrest is specifically shown in  FIGS. 11 and 12  and comprises a first footrest portion  44  and a second footrest portion  46  engaged with first footrest portion  44 . First footrest portion  44  extends away from the seat base  12  and comprises a second footrest engagement portion  48  for engagement with the second footrest portion  46 . First footrest portion  44  further comprises a seat base attachment portion  50  which engages with footrest attachment portion  52  of seat base  12 . 
     Second footrest portion  46  comprises a footplate  54  for receiving the foot of a user in use. The footplate  54  is arranged distal to the first footrest portion  44 . Second footrest portion  46  further comprises a first footrest engagement portion  56  dimensioned to slidably engage with the second footrest engagement portion  56  on the first footrest portion  44 . First and second footrest engagement portions form a footrest adjustment mechanism  58 . 
     Footrest adjustment mechanism  58  is composed of the second footrest engagement portion  50  of the first footrest portion  44  and the first footrest engagement portion  56  of the second footrest portion  46 . 
     First footrest portion  44  is provided with a plurality of recesses  64  and second footrest portion  46  is provided with a latch mechanism. 
     The latch mechanism comprises a latch  60  which is pivotable about fixed pivot point  62  and a coil spring  70 . Latch  60  comprises a coil spring engagement portion  72  which is engaged with coil spring  70 . Latch  60  further comprises a recess engagement portion  74  located on the same side of the pivot point  62  as the coil spring  70 . Recess engagement portion  74  is located adjacent recesses  64  and is dimensioned to be received within one of the plurality of recesses  64 . Coil spring  70  biases the latch  60  towards the recesses  64  and holds the latch recess engagement portion  74  within a selected recess  64 , in use. 
     The button portion  76  of latch  60  distal to the recess engagement portion  74  comprises a convex surface to allow easy engagement by a user during adjustment of the footrest adjustment mechanism  58 . 
     Thus, in use, the recess engagement portion  75  of latch  60  is biased by coil spring  70  into a recess  64 , thus preventing the first footrest engagement portion  56  and the second footrest engagement portion  48  from being slidable relative to one another. Once engaged, any pressure applied to the footrest in a downward direction will not encourage the latch  60  to be released from the recess  64 . Instead, the recess engagement portion  75  will be more firmly pushed into engagement with the recess  64  on application of downward pressure on the footplate  54  by the feet of a user. 
     On application of force by a user to the button portion  76  of latch  60 , latch  60  is pivoted about the fixed pivot point  62  to compress coil spring  70  and move coils spring engagement portion  72  of latch  60  out of engagement with recess  64 . Once the coil spring engagement portion  72  and recess  64  are disengaged, the first footrest engagement portion  56  may be slidably moved relative to the second footrest engagement portion  48 , thus moving the second footrest portion  46  relative to the first footrest portion  44  and altering the distance between the footplate  54  and the front edge  40  of seat base  12 . 
     Movement of the second footrest portion  46  in a direction away from the seat base  12  will extend the length of the footrest  22 , thus extending the distance between the footplate  54  and the seat base  12 . Subsequent return movement of the second footrest portion  46  back towards the seat base  12  will reduce the length of the footrest  22  and thus bring the footplate  54  closer to the seat base  12 . 
     After slidable movement of the second footrest portion  46  relative to the first footrest portion  44 , release of force on button portion  74  of latch  60  will allow the latch  60  to pivot back about fixed pivot point  62  under the biasing influence of coil spring  70  as it decompresses, thus bringing recess engagement portion  74  of latch  60  back into contact with the second footrest engagement portion  48  so that the recess engagement portion  74  of latch  60  may once again engage with one of the recesses  64 . The amount of adjustment made to the length of the footrest  22  depends on the amount of movement of the first footrest engagement portion  56  relative to the second footrest engagement portion  48 . The plurality of recesses  64  are provided at staggered intervals to permit a plurality of point of adjustment and therefore a corresponding number of different footrest  22  lengths that may be achieved using the same adjustable chair. 
     Thus, adjustment of the position of the second footrest portion  46  relative to the first footrest portion  44  will vary the overall length of the footrest  22  and, in particular, will vary the distance between the footplate  54  and the front edge  40  of seat base  12 . This allows the same adjustable chair to be used by users of different heights. More specifically, the footrest can be adjusted to suit users where the distance between the feet and knees of each user varies. This is particularly important where the chair is to be used by an individual child who will grow in height over time or where the chair is to be used by multiple individuals of different heights and/or tibia lengths. 
     Thus, without the need to alter the height of the chair, a user who is not sufficiently tall to place their feet on the ground when sitting in the chair can still use the chair with comfort by adjusting the footrest  22  length so that the footplate  54  is located an appropriate distance from the front edge  40  of seat base  12  to allow them to comfortably rest their feet on footplate  54  when seated on seat base  12 . 
     The seat base attachment portion  56  of the first footrest portion  44  is pivotably attached to the footrest attachment portion  52  of seat base  12 . Thus, footrest  22  can be pivoted about front edge  40  of seat base  12  to allow a user to pivot the footrest  22  out of the way when sitting down or getting up from the chair. 
     In the ‘rest’ position, the footrest  22  will hang approximately vertically under the influence of gravity. When sitting down, a user will typically position their legs slightly under the seat base  12 . As they move their legs into this position, the back of their lower legs will apply force to the footrest  22  to pivot it away from the vertical and slightly under the seat base  12 . As the user relaxes in the chair, and moves their lower leg forwards, the footrest  22  will return under gravity to the vertical ‘rest’ position and the user may then place their feet on the footplate  54 . This movement of the footrest  22  away from the vertical and under the seat base  12  is particularly useful when a user has their feet on the ground and is attempting to slide the chair, for example, under a desk or table. The footrest  22  will then swing away from the vertical under the influence of the user&#39;s legs, thereby not interfering with the user&#39;s intention whilst sliding the chair in a forward direction. 
     Alternatively, the pivot design could be modified to bias the footrest in the ‘rest’ position such that the footrest  22  will naturally sit vertically. However, due to the pivot geometry, if the chair is pushed backwards or forwards, the footrest  22  will swing under the influence of contact with the user&#39;s lower legs. However, if a downward force is applied to the footplate  54  by a user sitting in the chair, movement of the footrest  22  away from the vertical will be move difficult i.e. the greater the weight applied to the footplate  54 , the harder it will be to swing the footrest  22  backwards and forwards. This ensures that, when sitting in the chair, the footrest  22  is less likely to swing away from the vertical when a user is resting their weight on the footplate  54  through application of force through their feet. 
     It is to be appreciated that the latch design for both the backrest and footrest adjustment mechanisms is such that when load is applied it is not the pivots that are loaded. Instead, it is the outside of the catch that are loaded such that the latch is pushed in against the recess in which it is received. This avoids the situation where the pivots could shear under the weight of a user. 
     A seat back adjustment mechanism is located on each side of the chair in the described embodiment. However, a single footrest adjustment mechanism is provided, thereby providing the advantage of single-handed adjustment of the distance of the footplate  54  from the seat base  12 . 
     A centrally located pivot point for the footrest relative to the seat base is provided in the described embodiment, rather than a pivot point being provided at each side of the front edge of the seat base. The centrally located pivot point is out of reach of a user sitting on the chair. Whereas, if the pivot point was located at each side of the front edge of the seat base, there is a potential risk of the user&#39;s fingers being trapped when swinging the footrest if their hands were resting towards the front edge of the seat base  12 .