Reclining seat assembly and method of use

Abstract

A reclining seat assembly includes a seat structure having a backrest portion and a seat portion, a support cradle for the seat portion, a base support frame, an adjustment mechanism for connecting the seat structure to the support cradle, the adjustment mechanism being operable to move the seat structure fore and aft relative to the support cradle, and one or more pivot mechanisms connecting the support cradle to the base support frame so that the support cradle (and the seat structure attached thereto by the adjustment mechanism) can pivot relative to the base support frame. Also provided is a method of adjusting the balance of such a seat assembly, the method comprising operating the adjustment mechanism to move the seat structure fore and aft relative to the support cradle.

Description

[Technical Field]

[0001] The present invention relates to a reclining seat assembly of the type that tilts about a pivot point, and a method of using such an assembly.

[0002] The terms "pivot point" and "pivot mechanism" as used herein should be interpreted broadly to include, for example, pivot mechanisms of the type disclosed in WO2015 / 185894A1, or other types of mechanisms that use, for example, guide rails or swing links, as well as simpler mechanisms that provide rotation about an axle, shaft, fulcrum, rocker, etc.

[0003] The present invention is particularly applicable, but not limited to, to reclining chairs in which the angle between the backrest and seat is fixed and the backrest and seat move together as a unit when reclining, tilting about a pivot point. [Background technology]

[0004] Anthropometric variations pose a challenge in the design of reclining seats (e.g., recliners) that tilt about a pivot point because the relative location of a user's center of gravity varies from person to person (e.g., height, weight, overall body weight distribution, etc.). Variations in the location of a user's center of gravity relative to the pivot point can affect the balance of the seat assembly when the user reclines during use.

[0005] More specifically, a reclining seat assembly that tilts about a pivot point comprises a seat structure (i.e., a body support structure) that includes at least a seat portion on which a user sits and a backrest portion that supports the user's back. Optionally, the seat structure may further include a headrest portion and / or a legrest portion. Upon reclining, the entire seat structure rocks about the pivot point, maintaining a constant angle between the seat portion and the backrest portion. An example of such a seat assembly is described in International Publication No. WO 2015 / 185894 A1 by the present inventor and applicant.

[0006] In such reclining seat assemblies, it is desirable for the seat structure to pivot about a pivot point that is aligned with the combined center of gravity of the occupant and the seat structure. That is, when viewed from the side, the pivot point and combined center of gravity are aligned horizontally (and preferably vertically as well). When the combined center of gravity is aligned with the pivot point, the seat assembly has a good sense of balance. Advantageously, this allows the occupant to recline the seat structure fore and aft with little physical effort, creating a feeling of virtually "weightlessness."

[0007] However, if the resultant center of gravity is further forward than the pivot point, the occupant will have to exert more force to recline the seating structure, and conversely, if the resultant center of gravity is further rearward than the pivot point, the seating structure will tend to over-recline or tip backward.

[0008] Therefore, there is a need for a reclining seat assembly that can compensate for anthropometric differences between users so that reclining seat assemblies can be used balanced across a wide range of populations. Summary of the Invention

[0009] The present invention provides a method for adjusting the relationship between an individual's center of mass and the recliner mechanism of a reclining seat assembly to compensate for anthropometric variations between users and provide a more balanced chair comfort experience.

[0010] More particularly, the present invention provides a reclining seat assembly as defined in claim 1 of the accompanying claims. It also provides a method for using such a reclining seat assembly. Details of particular embodiments are set out in the dependent claims.

[0011] According to a first aspect of the present invention, there is provided a reclining seat assembly comprising a seat structure having a backrest portion and a seat portion, a support cradle for the seat structure, a base support frame, an adjustment mechanism for connecting the seat structure to the support cradle, the adjustment mechanism operable to move the seat structure fore and aft relative to the support cradle, and one or more pivot mechanisms connecting the support cradle to the base support frame, so that the support cradle (and the seat structure attached thereto by the adjustment mechanism) is pivotable relative to the base support frame.

[0012] Advantageously, the adjustment mechanism provides a way to compensate for variations in the position of the combined center of gravity of the seat structure and occupant by moving the seat structure forward or backward relative to the support cradle, allowing an individual to align the combined center of gravity with the recline mechanism to improve balance in the chair.

[0013] Preferably, in the seat structure, the angle between the backrest portion and the seat portion is fixed.

[0014] Preferably, the seat assembly is operable to perform a continuous free reclining motion (i.e., in an unconstrained manner in which the seat structure is not statically supported).

[0015] Preferably, the seat structure is mounted on an adjustment mechanism, which in turn is mounted on a support cradle.

[0016] In certain embodiments, the seat structure includes a seat frame (or substructure) to which the backrest and seat portion are attached, the seat frame being connected to an adjustment mechanism, and in such a case preferably the seat frame rests on the adjustment mechanism, which in turn rests on a support cradle.

[0017] In a currently preferred embodiment, the adjustment mechanism is located below the seat.

[0018] In a currently preferred embodiment, the adjustment mechanism comprises a lead screw.

[0019] The adjustment mechanism further includes a rotatable knob attached (directly or indirectly) to a proximal end of the lead screw, such that rotation of the knob rotates the lead screw. The rotatable knob can be located below and in front of the seat. The rotatable knob may be provided with a lock or tamper-resistant mechanism to prevent inadvertent, unwanted, or unwanted rotation of the knob by an unskilled or inexperienced user.

[0020] In certain embodiments, the distal end of the lead screw is attached to the seat structure (or seat frame) and the lead screw passes through a lead screw nut attached to the support cradle. In other configurations, the distal end of the lead screw is attached to the support cradle and the lead screw passes through a lead screw nut attached to the seat structure (or seat frame).

[0021] Advantageously, the adjustment mechanism may further comprise a pair of guide rails arranged parallel to either side of the lead screw, and one or more guide carriages on each guide rail, for supporting the weight of the seat structure and an occupant thereon, the guide rails being attached to the seat structure and the guide carriages being attached to the support cradle (or the guide rails being attached to the support cradle and the guide carriages being attached to the seat structure), the guide carriages and guide rails being arranged to transfer the load of the seat structure to the support cradle, such that this load is not supported by the lead screw itself.

[0022] Optionally, the seat assembly may further comprise an indicator gauge arranged to indicate the position of the seat structure or seat frame relative to the support cradle.

[0023] In alternative embodiments, the adjustment mechanism may consist of a rack and pinion arrangement with, for example, a worm gear unit, or a bevel gear with a spindle unit.

[0024] Optionally, instead of a rotatable knob, the adjustment mechanism may further comprise an electric motor that drives the seat structure back and forth relative to the support cradle. The seat assembly may further comprise a microprocessor configured to control the motor and a memory that stores one or more user-selectable presets that specify the range of drive of the adjustment mechanism by the motor, and / or one or more programs that control operation of the motor to dynamically change the tilt movement of the chair during use.

[0025] Optionally, the seat structure may further comprise one or more of a leg rest portion, a head rest portion, and a lumbar support portion.

[0026] Optionally, the base support frame may also be provided with a pedestal base.

[0027] Preferably, the seat assembly includes a pair of pivot mechanisms, one on each side of the base support frame. Preferably, each pivot mechanism is located above the seat (e.g., directly below an armrest of the seat assembly) and configured to impart a swinging action to the seat structure below the pivot mechanism. To provide a balanced swinging action, the pivot mechanisms are preferably located as close as possible to the expected combined center of gravity of the expected occupant and seat structure.

[0028] By way of example only, each pivot mechanism could comprise first and second bearings acting on and moving along first and second inclined surfaces, respectively, of a hub, the second inclined surface facing in the opposite direction to the first inclined surface, the hub being fixed to a base support frame and the bearings being attached to a support cradle (as in WO2015 / 185894A1), or the hub being fixed to a support cradle and the bearings being attached to a base support frame. Many other types of pivot mechanisms are possible.

[0029] According to a second aspect of the present invention, there is provided a method of adjusting the balance of a seat assembly according to the first aspect of the present invention, the method comprising operating an adjustment mechanism to move the seat structure forwards or rearwards relative to a support cradle. [Brief explanation of the drawings]

[0030] Embodiments of the invention will now be described, by way of example, with reference to the drawings in which: [Figure 1] FIG. 1 shows a reclining chair comprising a seat structure mounted on a support cradle by an adjustment mechanism that allows the seat structure to be moved fore and aft relative to the support cradle to compensate for anthropometric differences between users, and the support cradle is rotatable relative to an outer base support frame to provide the reclining function of the chair. [Figure 2]Figure 2 shows side views of the chair of Figure 1 in (a) the upright (forward) position, (b) the mid-recline position, and (c) the maximum reclining position, showing that the angle between the seat and backrest portions of the chair does not change during the reclining process. [Figure 3] FIG. 3 is a front view of the chair of FIG. [Figure 4] FIG. 4 is a top view (section AA of FIG. 3) of the adjustment mechanism of the chair, including a rotatable control knob and a lead screw for adjusting the adjustment mechanism. [Figure 5] FIG. 5 is a cross-sectional view (taken along line BB in FIG. 3) showing a portion of the seat structure of the chair (specifically, the seat frame) attached to a support cradle by an adjustment mechanism. [Figure 6] FIG. 6 is a perspective view (corresponding to the cross-sectional view of FIG. 5) of a seat frame attached to a support cradle by an adjustment mechanism. [Figure 7] Figure 7 corresponds to Figure 6, but with the seat frame removed to show in more detail the adjustment mechanism attached to the support cradle. [Figure 8] FIG. 8 is a side cross-sectional view of the chair of FIG. 1 in an upright position, with the adjustment mechanism in a "neutral" intermediate position. [Figure 9] 9 is a cross-sectional side view of the adjustment mechanism in the intermediate position of FIG. 8. FIG. [Figure 10] Figure 10 is a side cross-sectional view of the chair of Figure 1 in an upright position, with the adjustment mechanism in an extended position and the seat structure moved forward relative to the position of Figure 8. [Figure 11] 11 is a cross-sectional side view of the adjustment mechanism of FIG. 10 in the extended position. [Figure 12] Figure 12 is a side cross-sectional view of the chair of Figure 1 in an upright position, with the adjustment mechanism in a stowed position and the seat structure moved rearward relative to the position of Figure 8. [Figure 13] 13 is a cross-sectional side view of the adjustment mechanism in the retracted position of FIG. 12. FIG. [Figure 14]FIG. 14 is an excerpt from WO2015 / 185894A1 to show a seat reclining (pivot) mechanism in which the present invention can be used.

[0031] In the drawings, like elements are designated with like reference numerals throughout. DETAILED DESCRIPTION OF THE INVENTION

[0032] The present embodiment represents the best way known to applicant to practice the invention, but is not the only way in which the invention may be practiced.

[0033] While this study uses a freestanding reclining (tilting) chair as an example of a reclining seating assembly, it should be understood that the principles are applicable to other reclining seating assemblies, such as office chairs, task chairs, cinema, theater, and auditorium seating, back pain relief chairs, and specialized medical seating for frail elderly or disabled individuals.

[0034] The present invention is particularly suited to recliner chairs equipped with a swivel mechanism, such as that generally described in WO 2015 / 185894 A1, where the swivel mechanism is located directly below the armrests and above the seat. While such a swivel mechanism is used in the illustrated embodiment, other swivel mechanisms may also be used.

[0035] More specifically, the swivel mechanism of WO2015 / 185894A1 uses first and second bearings (on either side of the chair) that act on and move along first and second inclined surfaces, respectively, of a central hub (which essentially functions as a cam). The second inclined surface faces in an opposite direction to the first inclined surface. In the illustrated example (reproduced herein as FIG. 14), the bearings are attached to the reclining seating structure, and the hub is fixed relative to the base support frame. The hub's peripheral shape and its position relative to the reclining seating structure define the chair's motion path and balance, intended to provide a horizontal motion path for the combined center of gravity of the seating structure and user when reclining (or standing upright). Providing such a horizontal motion path for the chair and user's center of gravity improves the chair's sense of balance and allows the user to easily recline (or stand upright) with minimal effort, creating a "weightless" sensation. Indeed, reclining chairs such as those disclosed in WO2015 / 185894A1 and this study allow users to recline (or stand upright) freely, unconstrained, and continuously by simply pushing gently on the armrests, changing their posture, or altering their muscle tone. However, achieving this movement requires that the chair be well-balanced for a particular user, and as mentioned above, this can be hindered if the center of gravity of each user is different.

[0036] However, the present invention is not limited to the use of swivel mechanisms of the type disclosed in WO2015 / 185894A1, but is also applicable to seat assemblies of substantially similar configuration that employ a simple single pivot for reclining movement (e.g., as described in US 4,790,599), guide rails that provide movement similar to a single pivot (e.g., as described in US 6,012,774), linkage systems (e.g., as described in EP 0918480B1), or other swivel mechanisms.

[0037] The present invention is also applicable to chairs such as task chairs that have a tilting mechanism under the seat, or chairs such as rocking chairs that have a rocking device under the seat.

[0038] 1-3, 8, 10, and 12 illustrate a recliner chair 100 as an example of a reclining seat assembly embodying the present invention. Chair 100 has a seat structure 101 including a backrest portion 104 and a seat portion 110. To define a frame of reference referred to below, seat portion 110 is in a "forward" direction relative to backrest portion 104, and backrest portion 104 is in a "rearward" direction relative to seat portion 110. In other words, the "forward" direction is the direction a user faces when sitting in the chair in an upright position and facing forward, and the "rearward" direction is the opposite direction.

[0039] In the illustrated embodiment, the seating structure 101 also includes a headrest portion 102, a legrest portion 112, and a lumbar support portion 106. The headrest portion 102, the legrest portion 112, and the lumbar support portion 106 are each considered optional, and in a simpler embodiment, the seating structure 101 includes only a backrest portion 104 and a seat portion 110. As will be appreciated by those skilled in the art, the headrest portion 102, the backrest portion 104, the seat portion 110, the legrest portion 112, and the lumbar support portion 106 may be upholstered to provide comfort and support to the user.

[0040] 2, the illustrated seat structure 101 also includes a seat frame 114 to which are directly attached a backrest portion 104, a lumbar support portion 106, a seat portion 110, and a leg rest portion 112. The headrest portion 102 is attached to the backrest portion 104 and is therefore indirectly attached to the seat frame 114.

[0041] Similar to the chair disclosed in WO2015 / 185894A1, the illustrated chair 100 has a fixed angle between the backrest portion 104 and the seat portion 110, so that the backrest portion 104 and the seat portion 110 move together during reclining. Figure 2 illustrates the reclining motion of the chair, showing (a) an upright (forward) position, (b) a mid-recline position, and (c) a fully reclined position. It will be understood that, in practice, a continuous range of reclining positions is possible between the upright position shown in (a) and the fully reclined position shown in (c), and that the seat structure 101 is free to move continuously and fluidly between different reclining positions.

[0042] Optionally, the angle between the backrest portion 104 and the seat portion 110 may be adjustable before the reclining operation begins. In certain embodiments, the angle between the backrest portion 104 and the seat portion 110 may also be changeable during the reclining operation (e.g., synchronized with the seat reclining mechanism via one or more mechanical linkages).

[0043] Optionally, the positions and angles of the headrest portion 102, lumbar support portion 106, and leg rest portion 112 may be adjustable before reclining use, or may be changeable during reclining use (e.g., synchronized with the seat reclining mechanism via one or more mechanical links).

[0044] The illustrated chair 100 further includes an outer base support frame 118 attached to a shaft 122 and a base 124. The outer base support frame 118 is generally U-shaped, although other shapes are possible. The shaft 122 may include a rotation means, such as a memory return spindle. The base 124 may be a pedestal base or a star base, as shown. As will be appreciated by those skilled in the art, the outer base support frame 118, shaft 122, and base 124 may be made of, for example, a suitable engineering steel or other suitable metal or alloy. Armrests 108a, 108b are provided at the top of each side of the base support frame 118.

[0045] The seating structure 101 (including components 102, 104, 106, 110, 112, and 114) is pivotable as a whole within the base support frame 118 by pivot mechanisms 120a, 120b. The pivot mechanisms 120a, 120b are attached to opposite sides of the base support frame 118 and are positioned inwardly from the base support frame 118 toward the seating structure 101. As noted above, in the illustrated embodiment, the pivot mechanisms 120a, 120b are substantially similar to those disclosed in WO 2015 / 185894 A1 and are positioned below the armrests 108a, 108b and above the level of the seat bottom 110. However, as noted above, alternative pivot configurations are possible.

[0046] Before describing in detail how the present seat structure 101 is ultimately attached to the pivot mechanisms 120a, 120b, it is useful to first consider how this was achieved in WO2015 / 185894A1. See Figure 14 herein, which corresponds to Figure 6 of WO2015 / 185894A1.

[0047] From FIG. 14 , it can be seen that in WO2015 / 185894A1, the reclining seat structure 18 is comprised of a backrest portion 12, a seat portion 14, and a legrest portion 16. The reclining seat structure 18 reclines entirely within an outer base support frame (support structure) 20. The reclining seat structure 18 is pivotable relative to the base support frame 20 by seat reclining (pivot) mechanisms 30 attached to both sides of the base support frame 20. The seat reclining (pivot) mechanisms 30 connect the seat structure 18 to the base support frame 20 and allow the reclining seat structure 18 to pivot relative to the base support frame 20. Notably, in WO2015 / 185894A1, the reclining seat structure 18 is directly connected to the reclining (pivot) mechanisms 30 on the base support frame 20.

[0048] However, in this study, as shown in Figures 1-13, the seat structure 101 is not directly connected to the pivot mechanisms 120a, 120b. Rather, to allow the relationship between a user's center of gravity and the recliner mechanism to be adjusted to compensate for anthropometric variations between users, the reclining seat assembly 100 of the present invention includes a support cradle (or substructure) 116 and an adjustment mechanism 130 for connecting the seat structure 101 to the support cradle 116. The support cradle 116 is connected (directly or indirectly) to the pivot mechanisms 120a, 120b so as to be pivotable within a base support frame 118. The support cradle 116, like the outer base support frame 118, shaft 122, and base 124, may be made of, for example, a suitable engineering steel or other suitable metal or alloy.

[0049] The adjustment mechanism 130 operates to move the seating structure 101 fore and aft relative to the support cradle 116. In other words, the adjustment mechanism 130 operates to move the seating structure 101 in a fore-and-aft direction (as defined above) relative to the support cradle 116 when the seating structure 101 is in an upright position (e.g., as shown in FIG. 1 ). That is, the movement of the seating structure 101 occurs substantially within the plane of the seat 110 (more specifically, within the plane of the underside of the seat 110).

[0050] The pivot mechanisms 120a, 120b connect the support cradle 116 to the base support frame 118, allowing the support cradle 116 (and the seating structure 101 attached thereto by the adjustment mechanism 130) to pivot relative to the base support frame 118. In the illustrated embodiment, each pivot mechanism 120a, 120b is substantially as disclosed in WO 2015 / 185894 A1 and includes first and second bearings that act on and move along first and second inclined surfaces, respectively, of a central hub, the second inclined surface facing in an opposite direction to the first inclined surface. In the illustrated embodiment, for each pivot mechanism 120a, 120b, the hub is fixed to the base support frame 118 and the bearing is attached to the support cradle 116. However, in alternative embodiments, the hub may be fixed to the support cradle 116 and the bearing may be attached to the base support frame 118.

[0051] Using the adjustment mechanism 130 to move the seating structure 101 forward or backward relative to the support cradle 116 provides a way to compensate for variations in the position of the combined center of gravity of the seating structure 101 and the occupant, allowing the combined center of gravity to be aligned with the recliner mechanism, improving the balance of the chair.

[0052] More specifically, in the illustrated embodiment, as shown most clearly in Figures 5, 6, and 7, the support cradle 116 includes a base portion 116a and first and second arms 116b, 116c extending outwardly and upwardly on either side of the base portion 116a. An upper portion of each arm 116b, 116c is provided with a fixing point 116d, 116e, respectively, which connects the support cradle 116 to a respective pivot mechanism 120a, 120b. The base portion 116a includes a longitudinal recess in which the adjustment mechanism 130 is located.

[0053] Additionally, in the illustrated embodiment, the seating structure 101 includes a seat frame (or substructure) 114, made, for example, from a suitable engineering steel or other suitable metal or alloy, to which the backrest portion 104, seat portion 110, and other components are attached, and which is connected to the adjustment mechanism 130. The seat frame 114 is attached to the adjustment mechanism 130, which is attached to and connected to a support cradle 116. The adjustment mechanism 130 is located below the seat portion 110 of the seating structure 101.

[0054] In the illustrated embodiment, the adjustment mechanism 130 includes a lead screw adjustment assembly having a rotatable control knob 132. Manually turning the control knob 132 rotates the lead screw (134 in FIGS. 4, 5, 7, 9, 11, and 13) in a corresponding direction, causing the seat frame 114 (and seating structure 101) to move forward or backward relative to the support cradle 116 (depending on the direction of rotation of the knob 132). In the illustrated embodiment, the rotatable knobs 132 are located at the front of the seating structure 101, in front of and below the seat portion 110, and above the leg rest portion 112. The control knob 132 and the entire adjustment mechanism 130 are located on the centerline of the chair (i.e., midway between the two armrests 108a, 108b), allowing the components of the chair 100 itself to be balanced without adversely affecting the overall balance of the chair 100.

[0055] The presently illustrated adjustment mechanism 130 will now be described in more detail with reference to Figures 4 to 13. Figure 4 shows a plan view of the adjustment mechanism 130. Figures 5, 6, and 7 (already referenced above) show the support cradle 116 in more detail, illustrating how the adjustment mechanism 130 attaches the seat frame 114 to the support cradle 116, thereby allowing the seat structure 101 to be adjusted forward and rearward relative to the support cradle 116. Figures 9, 11, and 13 show further cross-sectional side views of the adjustment mechanism 130, with adjustment positions corresponding to the cross-sectional side views of the overall chair shown in Figures 8, 10, and 12, respectively.

[0056] 4 and 7, adjustment mechanism 130 includes a lead screw 134 with a control knob 132 attached to its front (proximal) end. A long, tubular lead screw cover 136 is preferably provided to cover the entire length of the lead screw exposed at the front of the chair. This is done for aesthetic reasons and to prevent lubricant from the lead screw from staining the user's clothing.

[0057] The lead screw 134 threadably engages and passes through a lead screw nut 144, which is held within a lead screw nut holder 146. The lead screw nut holder 146 is attached to the support cradle 116. (As best seen in FIGS. 7, 9, 11, and 13, the lead screw nut holder 146 may be mounted within a longitudinal recess in the support cradle 116.) The rearward (distal) end of the lead screw 134 is provided with a lead screw connector 150 that is attached to the seat frame 114. In the illustrated embodiment, the distal end of the lead screw 134 is provided with a shoulder screw fitting 148, which has a bore through which the shoulder screw fitting 148 passes. The shoulder screw fitting 148 is free to rotate within the bore of the lead screw connector 150. The distal end of the shoulder screw fitting 148 is larger than the bore in the lead screw connector 150, thereby retaining the lead screw connector 150. Thus, rotation of the lead screw 134 (by rotating the control knob 132) causes the distal end of the lead screw (where the lead screw connector 150 is located) to either pull the seat frame 114 forward (direction "F" in FIGS. 5, 10, and 11) or push the seat frame 114 backward (direction "B" in FIGS. 5, 12, and 13) relative to the support cradle 116, depending on the direction of rotation of the knob 132. Because the lead screw connector 150 is free to rotate relative to the shoulder screw fitting 148, it maintains a fixed orientation even as the lead screw 134 rotates. Nylon washers are advantageously provided on either side of the lead screw connector 150 to reduce friction between the lead screw connector 150 and the shoulder screw fitting 148 and to increase the load-bearing area when the lead screw 134 and shoulder screw fitting 148 are pushed and pulled while simultaneously rotating.

[0058] In the illustrated embodiment, to support the weight of the seating structure 101 and an occupant thereon, the adjustment mechanism 130 further includes guide carriages 140 movable along guide rails 142 disposed on either side of (and parallel to) the lead screw 134, as shown in FIG. 4 . The guide rails 142 are attached to the seat frame 114, and the guide carriage 140 is attached to the support cradle 116 (although in alternative embodiments, the guide rails 142 may be attached to the support cradle 116, and the guide carriage 140 may be attached to the seat frame 114). The load from the seating structure 101 and an occupant is transferred from the seating structure 101 via the guide carriages 140 and guide rails 142 to the support cradle 116, and from there via the pivot mechanisms 120 a, 120 b to the base support frame 118, the shaft 122, and the base 124. Thus, during use, the lead screw 134 supports only a sliding load against the linear guide, and does not bear any load from above from the seating structure 101 and an occupant. In practice, the lead screw 134 is usually adjusted with the chair in an upright position, where it is nearly horizontal and the sliding load is reduced, making it easier to operate.

[0059] As shown in FIGS. 6 and 7 (and FIG. 1 ), an indicator gauge 131 can be provided to easily inform a user of the relative position of the seat structure 101 (more specifically, the seat frame 114) and the support cradle 116 (e.g., before, during, or after adjustment of the adjustment mechanism 130). The indicator gauge 131 can be configured with a pointer 131a attached to the side of the seat frame 114 and a series of scales (or other indicia) 131b on the adjacent side of the support cradle 116, or vice versa. As shown, the pointer 131a can at least partially overlap the scales 131b on the side of the support cradle 116. As the seat frame 114 moves forward or backward relative to the support cradle 116, the position of the pointer 131a relative to the scales 131b similarly changes. The scales 131b can be labeled with numbers (e.g., representing the distance of movement), letters, or other symbols to easily inform a user of the position of the seat frame 114 relative to the support cradle 116.

[0060] 8-13 illustrate the effect that the use of adjustment mechanism 130 has on the overall configuration of chair 100.

[0061] First, FIG. 8 shows the chair 100 in an upright (i.e., non-reclined) position, with the adjustment mechanism 130 (more clearly shown in FIG. 9) in a "neutral" intermediate position, and the seat structure 101 likewise in a "neutral" intermediate position relative to the support cradle 116.

[0062] In comparison, FIG. 10 shows the chair of FIG. 8 with adjustment mechanism 130 (shown more clearly in FIG. 11) moved to an extended position by rotation of knob 132 and lead screw 134, and seat structure 101 moved forward (direction "F") relative to the position of FIG. 8.

[0063] Conversely, Figure 12 shows the chair of Figure 8 with the adjustment mechanism 130 (shown more clearly in Figure 13) moved to a stowed position by rotating the knob 132 and lead screw 134 in the opposite manner to Figures 10 and 11, and the seat structure 101 moved rearward (direction "B") relative to the position of Figure 8.

[0064] Optional mode control lever and related mechanisms Returning to Figure 1, the chair 100 shown includes several optional features that allow the user to control whether the chair operates in a so-called "floating" mode, in which the chair is unconstrained and freely tilts in a continuously variable manner, providing the user with the sensation of "weightlessness."

[0065] Control lever L at the front of armrest 108a is positioned to pull gear cable C, which is connected to an index plunger in body B. Rod R under the seat slides within body B as the chair reclines. When the user pulls control lever L, a pin in the index plunger is retracted, placing the chair in "levitation" mode. Rod R has grooves along its length that allow the index plunger pin to move without contact in the retracted position, or "levitation" mode. When the chair returns to an upright position, the pin snaps into another slot, maintaining the upright position. Thus, when the user pulls lever L, the pin is retracted, placing the chair in levitation mode. The user does not need to hold lever L the entire time the chair is in levitation mode; they can simply relax and enjoy the "weightless" feeling provided by levitation mode.

[0066] Possible Modifications and Alternative Embodiments While detailed embodiments have been described above along with some possible modifications and alternative embodiments, those skilled in the art will appreciate that many more modifications and alternatives may be made to the above embodiments while still enjoying the benefits of the present invention.

[0067] For example, in the described embodiment, the adjustment mechanism 130 is operable to move the seating structure 101 forward and backward (essentially in a horizontal plane) relative to the support cradle 116. However, other embodiments are possible in which a second adjustment mechanism moves the seating structure 101 vertically relative to the support cradle 116.

[0068] In the illustrated embodiment, the adjustment mechanism 130 comprises a lead screw adjustment assembly with a control knob 132 located at the center of the front of the chair. However, alternative adjustment mechanisms are possible for moving the seating structure 101 fore and aft relative to the support cradle 116. Alternative control means may also be used in place of the manually operated knob 132. Furthermore, the control knob 132 need not be located at the center of the front of the chair, but may be located elsewhere on the chair.

[0069] Alternative adjustment mechanisms include various manual gear mechanisms, such as a rack-and-pinion mechanism using a worm gear unit or a bevel gear mechanism using a spindle unit. Both of these mechanisms allow the control knob 132 to be located on the side of the chair. However, locating the control knob in such a location could lead to an unfamiliar user mistaking it for a recline knob and potentially causing the chair to become unbalanced. By locating the knob 132 at the front and center of the chair, as shown, this problem is avoided, clearly indicating to the user that its function is not to control the chair's recline.

[0070] In the presently preferred lead screw adjustment assembly, the position of the control knob 132 can be changed as needed by using one or more mechanical couplings (such as shafts or universal joints) between the control knob 132 and the lead screw 134. Using such couplings, the knob 132 can be located under the seat, on the back of the seat, or elsewhere on the chair.

[0071] In embodiments in which the adjustment mechanism 130 includes a manually operated control knob 132, an anti-tamper mechanism can be provided to prevent inadvertent, unwanted, or unnecessary turning of the knob, for example, by an unskilled or inexperienced user. Failure to do so risks causing the chair to become unbalanced. This is of particular concern in public environments such as spas and hotels, where many people may turn the knob out of curiosity without understanding how it affects the chair's operation. To address this issue, the knob 132 can be provided with a locking or anti-tamper mechanism so that it can only be "activated" (i.e., rotate the lead screw 134) with prior knowledge or instruction of the chair's operation and how to release the anti-tamper mechanism. Suitable locking or anti-tamper knobs (e.g., knobs that require the knob to be simultaneously pushed inward to engage the rotating lead screw 134 as it is turned) are commercially available.

[0072] In the illustrated embodiment, the lead screw nut holder 146 is attached to the support cradle 116 and the lead screw connector 150 is attached to the seat frame 114. However, in alternative embodiments, the lead screw nut holder 146 may be attached to the seat frame 114 and the lead screw connector 150 may be attached to the support cradle 116. In such cases, the method of operation of the adjustment mechanism is substantially the same as described above (although the control knob 132 may need to be relocated on the chair or replaced with an electric motor, as described below).

[0073] Instead of using a manually operated control knob 132, an electric motor or other actuator may be provided to drive the adjustment mechanism 130. The motor (or other actuator) may be coupled to the lead screw 134 described above, or may be otherwise coupled to the seating structure 101 and arranged to drive the seating structure 101 forward or rearward relative to the support cradle 116.

[0074] In one embodiment, the motor (or other actuator) is provided with a simple forward / backward control that can be operated by the user to cause the motor (or other actuator) to drive the seat structure 101 forward or backward depending on the user's requirements at the time.

[0075] Optionally, a microprocessor may be provided for controlling the electric motor (or other actuator). Advantageously, the microprocessor may be coupled to a memory that stores one or more user-selectable presets that specify the direction and degree to which the motor (or other actuator) drives the adjustment mechanism. Such presets may be user-specific, for example, to configure the chair for different users (e.g., to account for anthropometric differences between household members) or to impart different balance characteristics to the chair (e.g., to bias the chair's tilting motion toward an upright position). The user may select the desired preset via a user interface on the chair (e.g., a button or option on a touchscreen) or via sensors on the chair that respond to a wearable device worn by the user (e.g., Bluetooth, RFID tag, etc.). These sensors may identify the user.

[0076] Alternatively, or in addition, the microprocessor-controlled electric motors (or other actuators) described above may be configured to adjust the position of the seating structure 101 relative to the support cradle 116 during use, dynamically altering the tilt behavior of the chair during use. One or more programs may be stored in memory to cause the microprocessor to control the motors (or other actuators) in this manner.

[0077] According to one example program, the motors initially bias the balance of the chair toward an upright position, allowing the chair to be "weighted" in this position when not in use, facilitating the user's act of sitting in the chair. Once the user sits in the chair, the motors (or other actuators) then move the seating structure 101 relative to the support cradle 116 to a balanced position, ready for "floating" action.

[0078] Another example program may cause the motor to drive the seating structure 101 back and forth relative to the support cradle 116, possibly in a repetitive motion, to guide it to a position of optimum balance for the intended occupant. To this end, the chair may be equipped with one or more motion sensors, accelerometers, or inclinometers to provide feedback to the microprocessor as to the chair's degree of balance. In this manner, the chair may provide a "self-balancing" function.

[0079] Another example program may cause the motor to drive the seating structure 101 back and forth relative to the support cradle 116, so that the seating structure 101 gently rocks the occupant, for example, for stress relief. In this case, it is understood that the motor does not directly drive the rocking motion, but rather utilizes the influence of gravity to drive the rocking motion by periodically fine-tuning the balance of the chair. That is, the chair is slightly off-balance in alternating forward and backward directions, resulting in the rocking motion of the seating structure 101 due to the action of gravity.

[0080] A related program concept allows the chair's balance to be gradually changed, moving the sitter back and forth very subtly, without the user even noticing the movement, which constantly changes the pressure points between the user and the seat structure, further enhancing the user's "weightlessness" sensation.

Claims

1. 1. A reclining seat assembly comprising: a seat structure including a backrest portion and a seat portion; a support cradle for said seat structure; a base support frame; an adjustment mechanism by which the seating structure is connected to the support cradle, the adjustment mechanism operable to move the seating structure forward and rearward relative to the support cradle; one or more pivot mechanisms connecting the support cradle to the base support frame, allowing the support cradle to pivot relative to the base support frame; Reclining seat assembly.

2. 2. The seat assembly of claim 1, wherein the seat structure has a fixed angle between the backrest portion and the seat bottom.

3. 3. A seat assembly according to claim 1 or claim 2, operable to provide continuous free reclining movement.

4. A seat assembly according to any preceding claim, wherein the seat structure is mounted on the adjustment mechanism, and the adjustment mechanism is mounted on the support cradle.

5. 5. The seat assembly according to claim 1, wherein the seat structure includes a seat frame to which the backrest portion and the seat bottom portion are attached, the seat frame being connected to the adjustment mechanism.

6. 6. The seat assembly of claim 5, wherein the seat frame is mounted to the adjustment mechanism and the adjustment mechanism is mounted to the support cradle.

7. A seat assembly according to any preceding claim, wherein the adjustment mechanism is located below the seat portion.

8. A seat assembly according to any preceding claim, wherein the adjustment mechanism includes a lead screw.

9. 9. The seat assembly of claim 8, wherein the adjustment mechanism further includes a rotatable knob attached to a proximal end of the lead screw, such that rotation of the knob causes rotation of the lead screw.

10. 10. The seat assembly of claim 9, wherein the rotatable knob is located below and in front of the seat portion.

11. 11. A seat assembly according to claim 9 or claim 10, wherein the rotatable knob includes a locking or tamper-resistant mechanism.

12. The distal end of the lead screw is attached to the seat structure, and the lead screw passes through a lead screw nut attached to the support cradle; Alternatively, a distal end of the lead screw is attached to the support cradle, and the lead screw passes through a lead screw nut attached to the seat structure.

13. the distal end of the lead screw is attached to the seat frame, and the lead screw passes through a lead screw nut attached to the support cradle; or Alternatively, a distal end of the lead screw is attached to the support cradle, and the lead screw passes through a lead screw nut attached to the seat frame.

14. the adjustment mechanism further includes a pair of guide rails positioned parallel to and on either side of the lead screw, and one or more guide carriages on each guide rail; the guide rail is attached to the seat structure and the guide carriage is attached to the support cradle, or the guide rail is attached to the support cradle and the guide carriage is attached to the seat structure; 14. A seat assembly as claimed in claim 12 or claim 13, wherein the guide carriage and guide rail are configured to transfer loads of the seat structure to the support cradle.

15. A seat assembly according to any preceding claim, further comprising an indicator gauge configured to indicate the position of the seat structure relative to the support cradle.

16. A seat assembly according to any preceding claim, wherein the adjustment mechanism comprises a rack and pinion arrangement.

17. A seat assembly according to any preceding claim, wherein the adjustment mechanism includes a bevel gear having a spindle unit.

18. A seat assembly as claimed in any preceding claim, wherein the adjustment mechanism further comprises an electric motor operable to drive the seat structure forwards or rearwards relative to the support cradle.

19. 20. The seat assembly of claim 18, further comprising a microprocessor configured to control the motor and a memory storing one or more user-selectable presets specifying the direction and extent to which the motor drives the adjustment mechanism and / or one or more programs for controlling the behavior of the motor to dynamically change the tilt behavior of the chair during use.

20. The seat assembly of any preceding claim, wherein the seat structure further comprises one or more of a leg rest portion, a head rest portion, and a lumbar support portion.

21. A seat assembly according to any preceding claim, wherein the base support frame is provided with a pedestal base.

22. A seat assembly as claimed in any preceding claim, comprising a pair of pivot mechanisms, one on each side of the base support frame.

23. 23. The seat assembly of claim 22, wherein each pivot mechanism is located above the seat portion and configured to impart a rocking motion to the seat structure below the pivot mechanism.

24. each pivot mechanism includes first and second bearings that respectively abut against and move along first and second inclined surfaces of the hub, the second inclined surfaces facing away from the first inclined surface; the hub is fixed to the base support frame and the bearing is mounted to the support cradle; or Alternatively, the hub is fixed to the support cradle and the bearing is mounted to the base support frame.

25. 25. A method of adjusting the balance of a seat assembly as claimed in any preceding claim, said method comprising operating said adjustment mechanism to move said seat structure forward or rearward relative to said support cradle.

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