Chair and chair control assemblies, systems, and methods

Abstract

Chairs, seating systems, chair sub-assemblies and sub-systems, and associated methods of assembly and use. Aspects relate to chairs and methods of assembling chairs including chair controls of a relatively compact and effective design with desirable synchronous raising and tilting motions. Aspects also relate to tilt lock assemblies for achieving secure and effective tilt securement. Additional aspects relate to forward and rearward adjustment, or extension and retraction, of a seating assembly of the chair.

Claims

1. A seating system comprising: a base assembly configured to support the chair on a floor surface; a seat assembly configured to receive a posterior of a user; a back assembly configured to receive a back of the user; and a chair control assembly comprising: a plurality of riders coupled to the base assembly, the plurality of riders including a first rider and a second rider, a link arm including a body and a pivot link, the body being pivotably coupled to the base assembly and pivotably coupled to the pivot link, a seat support to which the pivot link is pivotably coupled, the seat support having a first channel extending between a front portion and a rear portion, the first channel extending at an angle between the front portion and the rear portion such that the front portion of the first channel is higher than the rear portion of the first channel, the seat support further having a second channel extending between a front portion and a rear portion, the second channel extending at an angle such that the front portion of the second channel is higher than the rear portion of the second channel, the angle of the first channel being different than the angle of the second channel, the first channel slidably receiving the first rider and the second channel slidably receiving the second rider, such that upon activation of the body of the link arm the first and second riders slide along the first and second channels, respectively to raise and lower the seat support such that a front portion of the seat assembly raises and lowers to a greater extent than a rear portion of the seat assembly raises and lowers.

2. The seating system of claim 1, wherein the seat support defines a front and a back, and further wherein the first channel is positioned nearer to the front of the seat support than the second channel.

3. The seating system of claim 1, wherein the seat support further includes a third channel and a fourth channel, the chair control assembly further includes a third rider coupled to the base assembly and a fourth rider coupled to the base assembly, and the third channel receives the third rider and the fourth channel receives the fourth rider.

4. The seating system of claim 3, wherein the seat support defines a front and a back, and further wherein the first and third channels are nearer to the front of the seat support than the second and fourth channels.

5. The seating system of claim 3, wherein the first and third channels extend at substantially the same angle, and the second and third channels extend at substantially the same angle, and further wherein the first and third channels are angularly offset from the second and fourth channels.

6. The seating system of claim 1, wherein the third channel extends at an angle that is substantially the same as the angle of the first channel and the fourth channel extends at an angle that is substantially the same as the angle of second channel.

7. The seating system of claim 1, wherein the angle of the first channel extends is steeper than the angle of the second channel.

8. The seating system of claim 1, wherein each of the first and second riders comprises a post portion and a sleeve portion received by the post portion.

9. The seating system of claim 7, wherein the sleeve portion is rotatably coupled to the post portion.

10. The seating system of claim 7, wherein the sleeve portion is configured to be non-rotatably coupled to the post portion.

11. The seating system of claim 7, wherein the post portion has a round transverse cross-section.

12. The seating system of claim 7, wherein the sleeve portion has a square transverse cross-section.

13. The seating system of claim 3, wherein each of the first, second, third, and fourth riders comprises a post portion and a sleeve portion.

14. The seating system of claim 13, wherein the sleeve portion is configured to be rotatably coupled to the post portion.

15. The seating system of claim 14, wherein the sleeve portion configured to be non-rotatably coupled to the post portion.

16. The seating system of claim 14, wherein the post portion has a round transverse cross-section.

17. The seating system of claim 14, wherein the sleeve portion has a square transverse cross-section.

18. A chair control assembly comprising: a plurality of riders including a first rider and a second rider; a link arm including an arm body and a pivot link, the arm body pivotably coupled to the pivot link; and a seat support to which the pivot link of the link arm is pivotably coupled to the seat support, the seat support having a plurality of channels each of which extends at angle, upwardly and rearwardly, such that a front portion of each of the plurality of channels is higher than a rear portion of each of the plurality of channels, the plurality of channels including a first channel and a second channel, the first channel receiving the first rider and the second channel receiving the second rider, such that upon activation of the arm body of the link arm the first and second riders traverse the first and second channels, respectively to raise and lower the seat support such that a front of the seat support is raised more so than a rear of the seat support.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a chair from an isometric view, according to some embodiments.

(2) FIG. 2 shows the chair with a seat assembly of the chair removed, according to some embodiments.

(3) FIG. 3 shows the control assembly of the chair from an isometric view, according to some embodiments.

(4) FIG. 4 shows the control assembly of the chair in a disassembled state, according to some embodiments.

(5) FIG. 5 shows a first chair control cartridge of the control assembly in a disassembled state, according to some embodiments.

(6) FIG. 6 shows a seat support of the chair from a first side view and FIG. 7 shows the seat support from an opposite, second side view, according to some embodiments.

(7) FIG. 8 shows the seat support from a bottom view, according to some embodiments.

(8) FIG. 9 shows a link arm of the chair control cartridge from a top view, according to some embodiments.

(9) FIG. 10 shows the link arm of the chair control cartridge from a side view, according to some embodiments.

(10) FIG. 11 shows the link arm of the chair control cartridge in a disassembled state, according to some embodiments.

(11) FIG. 12 shows the chair control cartridge from a side view in a first, lowered state and with some portions partially see-through to assist in understanding, according to some embodiments.

(12) FIG. 13 shows the chair control cartridge from a side view in a second, raised state and with some portions partially see-through to assist in understanding, according to some embodiments.

(13) FIGS. 14 to 16 show the link arm and a control body of the chair control cartridge in various states of actuation and with some portions partially see-through to assist in understanding, according to some embodiments.

(14) FIG. 17 shows a control assembly of the chair in the first lowered state from an isometric view, according to some embodiments.

(15) FIG. 18 shows the control assembly of the chair in the first lowered state from a side view, according to some embodiments.

(16) FIG. 19 shows the control assembly of the chair in the second, raised state from an isometric view, according to some embodiments.

(17) FIG. 20 shows the control assembly of the chair in the second, raised state from a side view, according to some embodiments.

(18) FIGS. 21 and 22 are isometric views of a portion of the chair showing the chair control assembly, according to some embodiments.

(19) FIG. 23 is a side view of a portion of the chair showing the control assembly and the back assembly of the chair, according to some embodiments.

(20) FIG. 24 shows the chair control assembly from an isometric view, according to some embodiments.

(21) FIG. 25 is a top view of a portion of the chair control assembly, according to some embodiments.

(22) FIGS. 26 and 27 are top views of a portion of the chair control assembly with portions removed for understanding, according to some embodiments.

(23) FIG. 28 shows the seat assembly of the chair from an isometric view, according to some embodiments.

(24) FIG. 29 shows the seat assembly of the chair from an isometric view according to a second point of view, according to some embodiments.

(25) FIGS. 30 and 31 are side views of a seat assembly of the chair, according to some embodiments.

(26) FIG. 32 is an isometric view of a portion of the chair, according to some embodiments.

(27) FIG. 33 shows the chair from a side view with the seat assembly in a fully retracted state, according to some embodiments.

(28) FIG. 34 shows the chair from a side view with the seat assembly in an fully extended state, according to some embodiments.

(29) While the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION

(30) FIG. 1 shows a chair 10 from an isometric view, according to some embodiments. FIG. 2 shows the chair with a seat assembly of the chair removed, according to some embodiments. As shown, the chair 10 includes a back assembly 12, a base assembly 14, a seat assembly 16, and a control assembly 18. The back assembly 12 includes an upper portion 20 and a lower portion 22, the lower portion 22 being adapted to be secured to the control assembly 18. As shown, the base assembly 14 includes a lower portion 30 configured to rest on a surface, such as a floor (not shown), to support the chair 10 in use, as well as an upper portion 32 configured to be secured to the control assembly 18. As shown, the lower portion 30 is configured as a pedestal and the upper portion 32 as a cylinder, although a variety of base assembly configurations are contemplated.

(31) As described in greater detail, the control assembly 18 is configured to transition the seating assembly from a lowered position to a raised position as the back assembly 12 transitions between an upright state, or upright position to a reclined state, or reclined position. In particular, in some embodiments the chair 10 is configured such that when the back assembly 12 is in a first upright state the control assembly 18 is in a first lowered state and when the back assembly 12 is in a reclined state the control assembly is in a second raised state. In some embodiments, the control assembly 18 is configured to raise a front portion of the seat assembly 16 more quickly and/or to a greater extent than a rear portion of the seat assembly 16 such that raised position includes the seat assembly 16 being tilted and moved upwardly and rearwardly.

(32) FIG. 3 shows the control assembly 18 of the chair 10 from an isometric view and FIG. 4 shows the control assembly 18 in a disassembled state, according to some embodiments. As shown in FIGS. 3 and 4, the control assembly 18 includes a hub 40, a first cartridge 42, a second cartridge 44, a back mount 46, a torsion assembly 48, a tilt lock assembly 50, and a height lever 52. In general terms, the control assembly 18 is coupled to the back assembly 12, the base assembly 16, and the seat assembly 18. The control assembly 18 also includes covers 56. As shown and according to some embodiments, the control assembly 18 is generally a central component that interconnects the back assembly 12, the base assembly 16, and the seat assembly 18.

(33) As shown in FIG. 4, the hub 40 includes a central opening 60, defines a front 62, a back 64, a first side 66, and a second side 68 and includes a variety of mounting features for securing various components of the control assembly 18 with fasteners such as bolts. As with all the various components of the chair 10, the hub 40 is formed of desired materials, such as polymeric or metallic materials for example.

(34) FIG. 5 shows the first cartridge 42 in a disassembled state, according to some embodiments. As shown, the first cartridge 42 includes a seat support 70, a link arm 72, and a control body 74. The second cartridge 44 is optionally similar to the first cartridge, e.g., with a support 70A of the second cartridge 44 being a mirror image of the first cartridge 42 as shown in FIG. 4. Thus, various features of the second cartridge 44 are not separately described, instead being described collectively with reference to the first cartridge 46. When specifically referenced, features of the second cartridge 44 and are designated by similar reference numbers to the first cartridge followed by an A when specifically referenced. Although similar cartridges 42, 44 are shown and described, it should be understood that differing cartridges are also contemplated.

(35) FIG. 6 shows the seat support 70 from a first side view and FIG. 7 shows the seat support 70 from an opposite, second side view, according to some embodiments. FIG. 8 shows, the seat support 70 from a bottom view, according to some embodiments. As shown, the seat support 70 includes a first flange 76, a second flange 78 spaced from the first flange 76, and a seat mount 80. The first flange 76 includes a front rider 81 and a back rider 82 and has a pivot aperture 83. The second flange 78 includes a front rider 85 and a back rider 86 and has a pivot aperture 87. The front riders 81, 85 are generally positioned opposite one another at a forward position on the seat support 70 and the back riders 82, 86 are positioned at a rearward position on the seat support 70. The first and second flanges 76, 78 define a gap 88, also described as a channel, for receiving the link arm 72 (FIG. 5). As shown, the seat mount 80 includes a plurality of notches 89, or recesses, that assist in providing a seat adjustment feature, as subsequently described in greater detail.

(36) As shown, the pivot apertures 83, 87 are coaxial with the front riders 81, 85, although the pivot apertures can also be located elsewhere. Additionally, as shown, the front and/or back riders 81, 85, 82, 86 are formed as monolithic projections with square transverse cross-sections with rounded corners. In some embodiments, one or more of the riders 81, 82, 85, 86 is formed as a two part component including a post having a round transverse cross-section and a sleeve having a square transverse cross-section with rounded corners, the sleeve being rotatably or non-rotatably received over the post.

(37) FIG. 9 is a top view of the link arm 72 and FIG. 10 is a side view of the link arm 72, according to some embodiments. As shown, the link arm 72 includes a body 90 and a pivot link 92. The body 90 has a first end 94 and a second end 96 and an intermediate pivot pin 98 located at an intermediate position between the first and second ends 94, 96. The body 90 also includes a locking recess 99 formed into the top of the body 90 toward the second end 96. As shown, the pivot link 92 includes a first end 100 that is pivotably connected to the second end 96 of the body 90. The pivot link 92 also includes a second end 102 having an aperture 104 for pivotably connecting the pivot link 92 to the seat support 70. As shown, the link arm 72 includes a link pivot pin 106 for pivotably securing the pivot link 92 to the body 90.

(38) FIG. 11 shows the link arm 72 in a disassembled state. As shown, the link arm 72 includes a plurality of plate members 110, or laminate members, secured together with the link arm 72 centrally interposed between the plate members 110 and pivotably connected thereto by the front pivot pin 106.

(39) Returning to FIG. 5, the control body 74 of the first cartridge 42 includes a first wall 120, or side portion, and a second wall 122, or side portion. As shown, the first wall 120 includes a first, rear channel 124, or slot and a second, front channel 126, or slot. The rear channel 124 extends in a first direction D124 and the front channel 126 extends in a second direction D126. The first wall 120 also includes a pivot recess 128, or hub for receiving the intermediate pivot pin 98 of the link arm 72. As shown, the first wall 120 also includes mating features for aligning and/or securing the first wall 120 to the second wall 122. The first wall 120 also has a locking aperture 129 to facilitate a tilt locking feature, as subsequently described.

(40) The second wall 122 is shown including a first, rear channel 130, or slot corresponding to the rear channel 124 of the first wall 120 and a second, front channel 132, or slot corresponding to the front channel 126 of the first wall 120. The rear channel 130 extends in a first direction D130 (parallel to and laterally offset from first direction D124) and the front channel 132 extends in a second direction D132 (parallel to and laterally offset from second direction D126). The second wall 122 also includes a pivot recess 138, or receiver that corresponds to the pivot recess 128 for receiving the intermediate pivot pin 98 of the link arm 72. The second wall 122 includes complementary mating features for aligning and/or securing the first wall 120 to the second wall 122. The second wall 120 also has a locking aperture 139 to facilitate a tilt locking feature, as subsequently described.

(41) Assembly of the first cartridge 42 includes receiving the link arm 72 in the gap 88 formed between the first and second flanges 76, 78 of the seat support 70. The front pivot pin 140 is received through the pivot apertures 83, 87 that extend through the front riders 81, 85. The first and second walls 120, 122 are positioned opposite one another about the link arm 72, as well as the flanges 80, 82 of the seat support 70. Upon assembly, the intermediate pivot pin 98 is received in the pivot recesses 128, 138 and the front riders 81, 85 are slidably and/or rotatably received in the front channels 126, 132 and the rear riders 82, 86 are slidably and/or rotatably received in the rear channels 124, 130. The link arm 72 is thereby pivotably secured to the control body 74 at an intermediate position on the link arm body 90 and the link arm pivot link 92 is pivotably secured to the seat support 70.

(42) FIG. 12 is side view of the first cartridge 42 with the first cartridge in a lowered state and FIG. 13 is a side view of the first cartridge 42 in a raised state, according to some embodiments. For ease of understanding, portions of the first wall 120 of the control body 74 and the seat support 70 are shown partially see through in FIGS. 12 and 13, such that the position and movement of the various components in operation, including the seat support 70 and the link arm 72 is more visible.

(43) As indicated in FIG. 13, the body 90 of the link arm 72 is rotated in a first direction R1 about a first pivot P1 which causes the pivot link 92 to rotate in a second direction R2 that is opposite to the first direction R1 about a second pivot P2. This rotation causes the front riders 81, 85 and the rear riders 82, 86 of the seat support 70 to move upwardly and rearwardly in the front channels 126, 132 and the rear channels 124, 130, respectively, of the control body 74. As shown, the motion of the riders in the channels causes the seat mount 80 of the seat support 70 to move from a first lowed support position S1 to a second raised support position S2. As indicated, the front of the seat mount 80 is raised to a relatively greater extent than the rear of the seat mount 80. In different terms, there is both a tilting motion, with the front of the seat support being tilted at an angle A and an upward and rearward motion of the seat mount 80 upon rotation of the body 90 of the link arm 72 in the first direction R1.

(44) In some embodiments, the raising and tilting action is adjusted by selecting the directions of the front channels D126, D132 and the rear channels D124, D130 and the relative angular offsets of those channels. In some embodiments, the rear sets of channels 124, 130 extend in parallel direction to the front set of channels 126, 132 such that only a raising and lowering motion (e.g., in an upward and rearward direction) is accomplished. In other embodiments, and as shown, the directions D126, D132 in which both the front channels extend is angularly offset from the direction D124, D130 in which both the rear channels extend to accomplish the described tilting action. In particular, and as shown, the front channels rise at a relatively steeper angle than the rear channels to accomplish rearward tilting, although the opposition angular offset (a relatively shallower front angle) can also be employed to achieve a forward tilting action.

(45) In some embodiments, the chair 10 is configured such that when the chair is supported on a horizontal surface, the front channels 126, 132 extend along directions D126, D132 at an angle of about 37 degrees relative to horizontal, or from about 20 degrees to about 60 degrees, for example, although a variety of angles are contemplated, and the rear channels 124, 130 extend along directions D124, 130 at an angle of about 25 degrees relative to horizontal, or from about 10 degrees to about 40 degrees, for example, although a variety of angles are contemplated. In some embodiments, the front channels 126, 132 are angularly offset from the rear channels 124, 130 by an absolute angle of about 12 degrees (in the counterclockwise direction as shown in FIG. 13), or from about 0 degrees to about 25 degrees, for example, although a variety of angles are contemplated.

(46) In some embodiments, the body 90 of the link arm 72 is secured to the lower portion 22 of the back assembly 12 with the back mount 46 and the seat assembly 18 is secured to the seat mount 80 of the seat support 70. The second control cartridge 44 is similarly secured to the back assembly 12 and the seat assembly 18 such that rearward tiling, or reclining, of the back assembly 12 causes the control assembly 18 to transition from the lowered state (FIG. 17) to the raised state (FIG. 19), thereby resulting in raising the seat assembly in an upward and rearward direction and also tilting of the seat assembly 18 in a rearward, or counterclockwise direction (from a right side view).

(47) FIGS. 14 to 16 show progressive movement of the first control cartridge 42 from the lowered state (FIG. 14) to the fully raised state (FIG. 16).

(48) FIG. 17 shows the back mount assembled to the rear portions of the link arms 72, 72A. As shown, the back mount 46 is configured to extend between the cartridges and includes recesses 137 (see also FIG. 22) for receiving a portion of the torsion assembly 48.

(49) FIGS. 17 and 18 show the control assembly 18 in an assembled state, with the control assembly 18 in the lowered state. FIGS. 19 and 20 show the control assembly 18 in an assembled state with the control assembly 18 in the raised state. As shown, the back mount 46 of the control assembly 18 is secured to the second ends of the bodies 90, 90A of the link arms 72, 72A. The first and second cartridges 42, 44 are maintained by the hub 40 on opposite sides of the hub 40. The tilt lock assembly 50 is positioned between the cartridges 42, 44 and is also maintained by the hub 40. The torsion assembly 48 is positioned rearward of the tilt lock assembly 50. The torsion assembly 48 facilitates return of the chair back assembly 12 to the upright position, return of the control assembly 18 to the lowered state, and also provides a desired resistance to tilting of the chair back assembly 12, according to some embodiments.

(50) FIGS. 21 and 22 are enlarged views showing the torsion assembly 48 in greater detail. As shown, the torsion assembly 48 includes torsion spring(s) 150, and an adjustment plate 152 secured to the hub 40. Although shown unsecured in FIGS. 3, 17, 21 and 22, first ends 156 of the torsion springs 150 are received under the adjustment plate 152 and an associated fastener 158, such as a bolt, is tightened or loosened to increase or decrease the spring tension, as shown more clearly in the side view of FIG. 23. Second ends 158 of the torsion springs 150 are received below the back mount 46 to provide the desired force/resistance against the back mount 46 and/or the back assembly 12.

(51) The tilt lock assembly 50 is shown in greater detail in FIGS. 24 to 27, according to some embodiments. As shown in the various figures, the tilt lock assembly 50 includes first and second tilt lock bars 170, 172, first and second lock gears 174, 176, tilt lock lever 178, and tilt lock spring 180. In FIGS. 26 and 27, the tilt lock lever 178 is not shown so the various components and locking operation are visible.

(52) As shown, the tilt lock lever 178 is rotatably coupled to the hub 40, as are the lock gears 174, 176. The lock gears 174, 176 are intermeshed and in turn are coupled to the tilt lock bars 170, 172 such that rotation of the gears results in extension or retraction of the tilt lock bars 170, 172. The tilt lock lever 178 is engaged with the tilt lock spring 180, which in turn is coupled to the first lock gear 174. In use, the tilt lock lever is rotated in a first direction, engaging the tilt lock spring 180, which in turn causes the first gear 174 to rotate. As the first and second gears 174, 176 are intermeshed, such that rotation of the first gear 174 results in rotation of the second gear 176. Rotation of the first gear 174 results in extension of the first tilt lock bar 170 through the lock aperture 129A, the locking recess 99A, and the lock aperture 139A of the second cartridge 44, thereby locking the link arm 72A to the control body 74A with the first tilt lock bar 170. In this manner, the second cartridge is locked in the lowered state. The first cartridge 42 is similarly (and simultaneously) locked by the second tilt lock bar 172 as it is extended by the second gear 176. This operation locks the control assembly 18, which is secured to the chair back assembly 12, thereby locking the chair 10 against tilting of the chair back assembly 12. Upon rotation of the tilt lock lever 178 in the opposite direction, the tilt lock bars 170, 172 are released from the cartridges 42, 44, allowing the chair 10 to take on a reclined state.

(53) By coupling the tilt lock lever 178 to the first gear 174 with the lock spring 180, a safety feature is optionally incorporated to help prevent inadvertent unlocking of the chair. In other words, if the chair back assembly 12 is being pushed rearwardly, an inadvertent pressure on the tilt lock lever 178 will be less likely to unlock the chair 10. Also, enhanced lock activation is also incorporated as the spring action provides a resilient force that helps the tilt lock bars 170, 172 locate and pass through the locking features in the cartridges 42, 44. Similarly, the tilt lock spring 180 acts as a clutch mechanism to allow a user to activate the lever 178 at any time during recline, where the tilt lock lever 178 remains in a locking position (e.g., by a detent or retaining means), and upon taking a sufficiently upright state (or non-reclined state), the tilt lock bars 170, 172 are activated to lock the chair 10 in the upright state.

(54) FIG. 28 shows the seat assembly 16 from a top-down oriented perspective view and FIG. 29 shows the seat assembly 16 from a bottom-up oriented perspective view. As shown, the seat assembly 16 includes an adjustable mount 200 on the bottom of the seat assembly 16, the adjustable mount including two opposing guide channels 202, 204 and a latch assembly 206 that mate with the seat supports 70, 70A (FIG. 17) of the first and second cartridges 42, 44.

(55) FIGS. 30 and 31 are side views of the seat assembly 16. As shown, the latch assembly 206 includes a front handle 208, an intermediate portion 210 that is pivotably coupled to a lower portion of seat assembly 16, and a rear clamp 212 that is configured to engage into the notches 89 of the seat support 70 (and 70A). As shown in FIG. 31, upon depression of the front handle 208, the rear clamp 212 is actuated downwardly.

(56) FIG. 32 is an enlarged view of a portion of the chair 10, showing the seat assembly 16 and the control assembly 18. As shown, the guide channels 202, 204 are slidably received over the seat supports 70, 70A such that the seat assembly 16 is able to be slide forward (and backward) upon disengagement of the rear clamp 212 from the notches 89 of the seat support 70 and notches 89A of the seat support 70A.

(57) As indicated previously, a method of assembling the chair 10 includes coupling the base assembly 14 to the control assembly 18. As shown in FIG. 32, the upper portion 32 of the base assembly 14 is configured as a cylinder that is received into the central opening 60 of the hub 40 and secured thereto. The seat assembly 16 is slidably secured to the control assembly 18 as previously described. The lower portion 22 (FIG. 23) of the back assembly 12 is secured to the back mount 46.

(58) FIG. 33 indicates a syncrotilt action of the chair 10, according to some embodiments. As shown, as the chair back assembly 12 transitions from a first, upright position T1 to a second, relatively tilted position T2, the seat assembly 16 transitions from a first lowered position S1 to a second raised position S2. As previously described, and as indicated in FIG. 33, the second raised position S2 of the seat assembly 16 includes the seat assembly 16 being moved upwardly and rearwardly relative to the first position S1, as well as tilted rearwardly relative to the first position S1.

(59) FIG. 34 illustrates the chair 10 with the seat assembly 16 in a fully extended position E1 relative to the fully retracted position E2, where the chair 10 is shown in the retracted portion in FIG. 33. As previously indicated, upon depression of the front handle 208 of the latch assembly 206, the rear clamp 212 is actuated to facilitate adjustment, or sliding of the seat assembly 16 on the control assembly 18.

(60) Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.