HK1173353B - Reclining chair with enhanced adjustability - Google Patents

Description

Reclining chair with enhanced adjustability

This patent application is a divisional application of patent application No. 200780014612.4 (international application No. PCT/US2007/064413), entitled "reclining chair with enhanced adjustability" by the applicant "HNI technology corporation.

Technical Field

The present invention relates to an ergonomic chair, and in particular to an adjustable reclining chair.

Background

Ergonomic office chairs are typically constructed so that the back can recline alone, the seat and back can recline in their entirety, or the back can recline in a coordinated proportion with the seat. The latter two are both referred to as "synchrotilt" chairs. Most synchronous recliners have a mechanism for loading a spring as the user reclines and a mechanism for adjusting the resistance to recline (also known as tilt or chair tension). In these seats, the preload on the spring requires the user to input a high force or large displacement in order to make any adjustments to the seat tilt tension. These adjustments are often difficult, inflexible, or require significant user labor to produce a perceptible change in tension. In addition, most chairs do not provide visual or tactile feedback to the user as to the range of tension adjustment that can be made and where within that range the chair is currently. Thus, many users do not take full advantage of the variety of seats that provide comfort. For example, many chairs provide a rotatable knob or handle with plus or minus symbols on the underside of the seat. Rotation of these knobs requires 30 or more turns to adjust the tension between the lowest and highest levels available.

As discussed above, the forces applied to the chair back during recline may also create shear forces between the user's back and the chair back. This shear force may be perceived by the user as a tendency of the chair back to pull out the user's shirt hem, known in the industry as "shirt pull". Furthermore, reclining on this type of seat can also result in a "pull-apart" between the seat back and the user's back, such that the seat back does not remain in contact with the user's back as the seat reclines. As a result, the seat does not provide adequate support, resulting in discomfort and dissatisfaction.

In addition to adjusting the tilt tension, many of these seats include a tilt lock for preventing the seat from tipping backwards, a seat height adjustment device, an armrest adjustment device, and/or a seat position adjustment device. There is also a need for improvements in other adjustment arrangements for seats to make them more user friendly and to encourage users to utilise the various available adjustment arrangements in order to customise the seat to the personal comfort requirements or work pattern requirements of the user.

Disclosure of Invention

The present invention can overcome the above-mentioned disadvantages of the prior art by providing an adjustable lounge chair comprising: a seat configured to support a user; a chair back; a base; and a control mechanism mounted on the base. The control mechanism connects the chair back to the seat such that the chair back is substantially adjacent to the back of the user when the user base is on the seat. The control mechanism includes a resistance adjustment mechanism for varying a resistance of the control mechanism to a reclining force applied by a user to the seat back to move the seat back rearward from an upright position. The resistance adjustment mechanism is activated by the weight of a user seated in the seat, making it easy to adjust the resistance to the seat in the upright position.

The present invention also provides an adjustable lounge chair comprising: a chair back; a chair seat; a base having a central axis; and a control mechanism mounted on the base, the control mechanism connecting the chair back to the seat. The control mechanism is configured as a four-bar mechanism including a base member and a pivot member pivotally connected to the base member at a pivot point forward of the central axis, the pivot member being pivotally connected to the seat back at a rear pivot. A reclining force applied by a user to the chair back causes the chair back to move rearward, causing the pivot member to pivot relative to the base member about the pivot point and the chair back to pivot about the rear pivot, wherein the chair back remains substantially in contact with the user's back due to reduced shear and pull-away forces.

The present invention also provides an adjustable chair back comprising a back frame, a resilient material connected to the back frame, the resilient material being held in tension across the chair back, and an adjustment mechanism connected to the frame and engaged with the resilient material. The adjustment mechanism is configured to change a stiffness of the resilient material of the seat back.

Drawings

FIG. 1 shows a perspective view of a chair in an upright position including a mesh chair back and fixed armrests according to the present invention;

FIG. 2 shows a right side view of the seat shown in FIG. 1;

FIG. 3 illustrates a right side view of the seat shown in FIG. 1, the seat being in a reclined position;

FIG. 4 illustrates a perspective view of a chair in an upright position including a upholstered chair back and adjustable armrests according to the invention;

FIG. 5 shows a right side view of the seat shown in FIG. 4;

FIG. 6 shows a right side view of the seat shown in FIG. 4, the seat being in a reclined position;

FIG. 7 illustrates a partial perspective view of the seat structure of the chair of FIG. 1 as viewed from the front and underside;

FIG. 8 illustrates a bottom view of a portion of the seat structure of FIG. 7;

FIG. 9 shows an exploded view of the seat pan and the locking lever;

FIG. 10 shows a perspective view of a seat plate used in the seat construction of FIG. 7;

FIG. 11 shows a left side view of a portion of the seat structure with the locking lever in the locked position;

FIG. 12 shows the seat construction of FIG. 11 with the locking lever in the unlocked position;

FIG. 13 illustrates a partial right side view of the chair of FIGS. 1 and 2 including a chair back, seat structure and control mechanism, the chair being in an upright position;

FIG. 14 illustrates the seat portion of FIG. 13 with the seat in a reclined position;

FIG. 15 shows an exploded view of the control mechanism, excluding the upper portion of the back upright;

FIG. 16 shows a further exploded view of the control mechanism of FIG. 15 showing the control body components;

FIG. 17 shows a partial side detail view of a seat back pivot for the seat in the upright position;

FIG. 18 illustrates the pivot axle shown in FIG. 17 for the seat in the reclined position;

FIG. 19 shows a top cross-sectional view of the pivot shaft shown in FIGS. 17 and 18;

figure 20 illustrates a partial top cross-sectional view of the chair back shown in figures 17-19 showing the pivot axis and the user's spine position;

FIG. 21 shows a partial detailed view of the control body and rear linkage assembly including a tension adjustment lever;

FIG. 22 shows a top view of the assembly shown in FIG. 21 with the tension slider in a final position;

FIG. 23 shows the assembly of FIG. 22 with the tension slide in a forward most position;

FIG. 24 illustrates a partial cross-sectional view of the control mechanism showing optional adjustment of the rear link projection;

FIG. 25 illustrates a top view of a portion of the back upright and control body assembly including the tilt lock mechanism in an unlocked position;

FIG. 26 shows the assembly of FIG. 24 with the tilt lock mechanism in a locked position;

FIG. 27 shows a partially exploded view of the control body including the height adjustment lever assembly;

FIG. 28 shows a partial rear view of the assembly shown in FIG. 27;

FIG. 29 shows a view of the assembly shown in FIGS. 27 and 28, in an assembled state;

FIG. 30 illustrates a partial view of the chair of FIG. 1 including a mesh chair back and control mechanism;

FIG. 31 illustrates a partial top view of the chair of FIG. 1 with the seat not shown;

FIG. 32 illustrates a partially exploded view of the mesh chair back of the chair of FIG. 1 showing components of a lumbar support system;

FIG. 33 illustrates a partial rear view of the seat portion illustrated in FIG. 31;

FIG. 34 illustrates a partial view of the upholstered seat back of the seat illustrated in FIG. 4 with the fabric and foam pad removed;

FIG. 35 illustrates an exploded view of the chair back of FIG. 34 showing components of the lumbar support system; and

figure 36 illustrates a rear view of the chair back shown in figure 34.

Detailed Description

Referring to the drawings, it should be understood that like parts are designated by like reference numerals throughout the several views. Unless otherwise specified, the components described herein with respect to the present invention may be formed from any suitable material and may be formed by any suitable manufacturing method. For example, the components may be formed of plastic, such as glass filled nylon or other moldable materials, or molded aluminum.

Fig. 1-3 illustrate a lounge chair 100 according to a first embodiment of the present invention, and fig. 4-6 illustrate a lounge chair 105 according to a second embodiment of the present invention. The first chair 100 includes a back 110, a seat 120, a base 130, an armrest 140, and a control mechanism 200. The second chair 105 includes a back 115, a seat 120, a base 130, an armrest 145, and a control mechanism 200. The back 110, 115, seat 120 and arm rests 140, 145 are all connected to a control mechanism 200, the control mechanism 200 being mounted on a base 130. In fig. 1, 2, 4 and 5, the seats 100 and 105 are in an upright position. In fig. 3 and 6, the seats 100 and 105 are in a reclined position.

In the first embodiment, the chair back 110 includes a frame 111 and a region of mesh fabric 112 attached to the frame 111. The chair back 110 is connected to the control mechanism 200 at a rear pivot 113. In the second embodiment, the chair back 115 includes a frame 116 and an upholstered portion 117. The seat back 115 is connected to the control mechanism 200 at a rear pivot 118. The seat backs 110 and 115 will be described in more detail below.

In the first embodiment, the armrest 140 is a fixed design that is coupled to the control mechanism 200. In a second embodiment, the armrest 145 is an adjustable design that is coupled to the control mechanism 200. The armrest 145 includes a padded armrest 146 and a mechanism 147 for raising or lowering the armrest 146. In addition, the armrest 146 is configured to move inward, outward, forward, and rearward. Alternatively, the seats 100 and 105 may be provided without armrests. Those of ordinary skill in the art will appreciate that various types and styles of chair arm rests 140 may be used in conjunction with the chairs 100 and 105, including arm rests that are angularly adjustable relative to the seat. All such armrest configurations are within the scope of the present invention.

The seat 120, base 130, and control structure are identical, although the style of the backs 110 and 115 and the style of the arms 140 and 145 may vary between the chair 100 and the seat 105. For clarity of discussion, these components are described below with respect to the seat 100 only. However, it should be understood that these discussions apply equally to the second embodiment seat 105 and any other variations described herein or contemplated based on the present invention.

The base 130 includes a central post 131, the central post 131 being supported by a plurality of outwardly extending base legs 134. Each base leg 134 is provided with a caster 135, the caster 135 being configured to rotate and roll in order to move the chair 100. In some embodiments, each caster 135 can include a locking mechanism. The central column 131 preferably comprises a pneumatic or pneumatic cylinder having a fixed outer cylinder 132 and a movable inner cylinder 133 connected to the control mechanism 200. Activation of the height adjustment lever 136 can cause the control mechanism 200 to move up or down and thus the chair backs 110, 115, the seat 120, and the arm rests 140, 145 to move up or down as is known in the art.

Referring now to fig. 7-12, the seat 120 preferably includes a cushion foam assembly 121, the assembly 121 being mounted to a rigid seat pan 122 by fasteners 123 or any other suitable method. The seat pan 122 includes one or more seat posts 124 extending from a side opposite the foam assembly 121 or a bottom side 125 of the seat pan 122. The seat post 124 may be attached to the seat pan 122 or may be integral with the seat pan 122 as desired. The seat pan 122 also includes one or more T-shaped slots 127 formed in the bottom side 125 and a central channel 128.

A substantially U-shaped pivoting locking lever 150 is mounted to the underside 125 of the seat pan 122 at the pivot mounting element 129 using a pivot block 151 and fasteners 152 (the pivot block 151 and pivot mounting element 129 will be described in more detail below). The lever 150 includes a lever handle 153 disposed between two legs 154. The lever handle 153 is positioned near the front edge 126 of the seat pan 122 when the lever 150 is mounted to the seat pan 122. Each lever leg 154 includes a recessed protrusion 155, the protrusion 155 being disposed on an end 156 opposite the lever handle 153. A spring 157 is also provided to bias the lever 150 to a "locked" position relative to the seat pan 122 such that the notched protrusions 155 are forced upward toward the bottom side 125 of the seat pan 122. Although shown as a U-shaped member, the locking lever 150 may alternatively be provided as an L-shaped member having a handle and only one leg, or in other suitable configurations.

The control mechanism 200 includes a seat plate 210, the seat plate 120 having a top side 211 and a bottom or bottom side 212. On the top side 211, the seat plate 210 includes two pairs of T-shaped protrusions 213 and a center rib 214. In addition, two slots 215 are formed through the seat plate 210, which are positioned on either side of the center rib 214. A series of teeth 217 are formed on the bottom side 212 of the seat plate 210 along each edge 216. An extended lip 218 is also provided on the bottom side 212 for connecting the seat plate 210 to the back upright 230 at pivot 201.

The seat 120 may be slidably mounted to the seat plate 210 of the control mechanism 200 by inserting the seat post 124 into the slot 215 of the seat plate 210, inserting the T-shaped protrusion 213 into the T-shaped slot 127, and inserting the center rib 214 into the center channel 128. The locking lever 150 is then mounted and attached to the seat pan 122 such that the two notched protrusions 155 are positioned to mate and engage with the teeth 217 on the seat plate 210, as shown in detail in fig. 11. In the normal, locked position, the engagement of the locking lever 150 with the teeth 217 maintains the seat stationary relative to the seat plate 210 (and thus the control mechanism 200).

A user seated on the seat 120 may wish to adjust the seat position, as indicated by directional arrow 101, either forward (F) or backward (B) to accommodate the size of the user or the preferred fit of the chair 100. Thus, the seat 120 moves relative to the control mechanism 200 and, thus, relative to the arm rest 140 and the chair back 110 coupled to the control mechanism 200. To make the adjustment, the user reaches under the front edge 126 of the seat 120 and lifts the lever handle 153 with either hand, preferably by grasping the seat 120 and handle 153. The locking lever 150 pivots about the pivot block 151 such that the grooved protrusion 155 disengages from the teeth 217, as shown in detail in fig. 12. The seat 120 is then free to slide along the slot 215 to the desired new position. Once the desired position is achieved, the user releases the handle 153 and the notched protrusions 155 re-engage the teeth 217 due to the force of the springs 157.

Referring now to fig. 13 and 14, a control mechanism 200 is shown having a seat 120 and a back 110, but without chair arms 140 and 145. Which includes a seat plate 210, a back upright 230, a rear link 290, and a control body assembly 260. The control mechanism 200 functions as a four-bar mechanism, with the control body assembly 260 or control shaft serving as the "ground" for the mechanism. The mechanism 200 includes a first pivot 201 between the back upright 230 and the base 260, a second pivot 202 between the back upright 230 and the seat plate 210, a third pivot 203 between the seat plate 210 and the rear link 290, and a fourth pivot 204 between the rear link 290 and the base 260. The portion 232 of the back upright 230 between the first pivot 201 and the second pivot 202 acts as a driver for the four-bar mechanism, the seat assembly 220 (seat 120 connected to the seat plate 210) acts as a coupler, and the rear link 290 acts as a follower.

The back upright 230 is a substantially J-shaped rigid unit when viewed from the side, extending downwardly from the central region of the chair back 110 at the rear 102 of the chair, and forwardly under the seat 120 to the front 103 of the chair 100. In one embodiment, the back upright 230 is divided into an upper portion 250 and a lower portion 251 that are joined together at a joint 252 near the rearward portion 222 of the seat 120. In this embodiment, the tab 252 is formed with a male portion 253 on the upper portion and a female portion 254 on the lower portion, the male portion 253 and female portion 254 being held together by a fastener 255. Providing the back upright 230 in multiple parts allows for more compact transportation of the seat 100. Furthermore, it facilitates more efficient (and therefore cost effective) manufacturing and assembly.

As will be described in more detail below, and as shown in fig. 1, at the seatback 102 of the seat 100, the upper portion 250 of the seatback upright 230 is substantially Y-shaped, terminating at pivots 113 on either side of the seat seatback 110. At the front 103 of the seat 100, the bottom 251 of the back upright 230 splits into two parallel prongs 231 between which the control body 260 is positioned, as shown in fig. 15 and 16.

When a user sitting in the chair 100 reclines the chair 100, as shown in figures 3, 6 and 14, a force is applied to the chair back 110 and to the upper portion 250 of the back upright 230 causing it to pivot about the first pivot point 201. The relative movement between the back upright 230 and the seat assembly 220 is defined by the second pivot point 202. The pivot point 202 is the forward most pivot point of the four-bar mechanism. When the user reclines, the position and angle of the coupler or seat assembly 220 changes in both the horizontal and vertical orientations. In effect, the back upright 230 and the four-bar mechanism 200 redirect the force applied to the back upright 230 to raise the seat assembly 220. That is, the chair 100 utilizes the weight of the user and the reclining force applied by the user to assist in lifting the user.

Referring now to fig. 13 and 17-21, the rear pivot 113 is shown in greater detail. As described above, the back upright 230 is attached to the chair back 110 at pivot 113. In this embodiment, the upper portion 250 of the back upright 230 includes a three-bladed pivot connector 233 that mates with the C-shaped back bracket 114 and is connected to the bracket 114 by a pin 234, the pin 234 being held in place by a clip 240, forming a joint 241. This type of joint 241 is provided for mechanical and stability purposes, however, any type of pivot joint known in the art may be suitable for use in this application. All such pivot joints are within the scope of the present invention.

The tab 241 is spring loaded with a predetermined preload by compressing the spring 235 to position the seat back 110 in its default upright position and provide resistance to rotation during reclining of the seat 110. In the upright position, as shown in fig. 17, the seat back 110 is properly positioned relative to the seat back upright 230 due to the restriction provided by the upright stop 236 on the pivot connector 233 engaging the upright bracket stop 237 on the seat back bracket 114. In the reclined position, a recline stop 238 on the pivot connector 233 engages a recline bracket stop 239 on the back bracket 114, serving as a limit to the rotation of the back 110 relative to the back upright 230. Two such pivot joints 241 are provided on the seat 100. They are coaxial and equidistant from the center plane reference. The purpose of the two pivot joints 241 is to bring the pivot axis 242 closer to the spine of the user. This may be accomplished by the curvature of the chair back 110.

The pivot axis 242 of the seat back 110 relative to the seat back upright 230 extends through the joint 241 at the pin 234. As shown in fig. 13, 14 and 20, this axis 242 is positioned near the center of the seated user's vertical force 243. The purpose of this position is to allow the chair back 110 to passively adapt to the movement of the user's torso. If the pivot axis 242 is located vertically above the center of the force 243, it will not rotate during the reclining action of the chair 100, thus allowing the user's back to separate from the chair back 110 itself. If the pivot axis 242 is vertically below the center of the user's force 243, the chair back 110 will rotate to its rearward stop 239 relative to the back upright 230 before the chair 100 begins to recline. The center of the user's force 243 is located near the center of mass of the user's torso.

The purpose of the horizontal positioning of the pivot axis 242 relative to the user's spine (as represented by reference numeral 246) is to facilitate proper spine positioning as the chair back 110 rotates. If it is located behind the level of the user's spine, the chair back 110 may improperly lift the user's lower back and push the user out of the chair 100. If it were to move horizontally away in either direction, it would cause slippage between the surface of the chair back 110 and the user's back.

The control mechanism 200 and back pivot 113 according to the present invention as described above are combined to provide a chair 100 in which the shearing and unzipping forces on the user's back encountered by other recliners are significantly reduced, if not eliminated. Thus, the user experiences a comfortable and customized fit, including proper back support in both the upright and reclined positions. The increased comfort of the office chair helps to improve work efficiency and reduce discomfort, fatigue, or other physiological problems for the user.

Turning now to fig. 15 and 16, and 21-23, the rear link 290 is formed as a wedge-shaped member that includes two bores 291 and 292 that correspond with the third pivot 203 and the fourth pivot 204, respectively. Shafts 293 and 294 connect the rear link 290 to the seat plate 210 and the control body 260 at bores 291 and 292, respectively.

The control body 260 includes a spring 261, the spring 261 acting between the rear link 290 and the base 260. When the reclining force is removed, the chair 100 returns to its upright forward position due to the action of the spring 261 and the weight of the user. In one embodiment, the spring 261 is provided as a steel coil spring that is preloaded. The rear link 290 includes a substantially flat bottom surface 295, the bottom surface 295 being positioned to engage the coil spring 261. The size, spring strength, location, and style of the spring 261 allow it to provide the desired return effect while increasing or decreasing the minimum resistance to reclining of the seat 100.

The control body 260 also includes a second spring 262, the second spring 262 acting between the rear link 290 and the base 260. The second spring 262 is formed from a block of resilient material that has a varying resistance to compression. By adjusting the position of the second spring 262 within the control body 260 relative to the rear link 290, the resistance of the seat to recline of the seat back 110, i.e., the seat's tilt tension, can be varied.

In this embodiment, the varying resistance to compression of the spring 262 is provided by varying a geometric parameter of the spring 262, such as by varying the amount of compressed elastic material within the tissue spring 262. This change is due to the removal of the wedge-shaped volume of material 263 from the interior of the block of resilient material. Alternatively, the change may be achieved by changing the material, for example by changing the density, formulation or other characteristics of the spring. Other methods of varying the resistance to compression of the spring 262 known in the art may also be used and such embodiments are also within the scope of the present invention.

The rear link 290 also includes a downwardly projecting member 296, the member 296 being positioned on the resilient second spring 262. In this embodiment, element 296 is configured substantially as a trapezoidal prism having rounded ends that engage resilient spring 262. The curved shape of the protrusion 296 provides a discrete area of contact with the resilient spring 262, thereby more accurately transmitting changes in resistance as the spring 262 moves relative to the protrusion 296. Further, because the resilient material may wrap around the protrusion 296 when compressed, the curved shape prevents the spring 262 from sliding relative to the protrusion 296.

The resilient spring 262 is retained within a slider 264, the slider 264 being mounted on a track 265 of the control body 260, as shown in figure 22. The protrusions on the bottom side of the slider 264 engage with the grooves on the track 265 to provide a recessed location for the slider 264. A slider or tension rod 266 is pivotally mounted to the control body 260 at a slider pivot 267 and movably connected to the slider 264 at a contact face 268. The tension rod 266 extends from the control body 260 to one side of the seat 100 and can move forward and backward relative to the control body 260. As the user moves the lever 266, the slider 264 moves the resilient spring 262 under the protrusion 296 of the link 290, thereby changing the resistance to reclining or tilt tension of the seat. Movement of the slider 264 relative to the groove track 265 requires a slight upward movement of the slider 264 over each groove. This upward movement is provided by a compliant spacer assembly 269 at the slider pivot 267. The initial pressure of the shim assembly 269 dictates the force required to move between the recessed positions of the rail 265. The limited distance movement of the tension bar, together with the tactile feel of the grooved track, provides the user with perceptible feedback regarding the tilt tension adjustment range and the user's adjustment within that range.

Alternatively, instead of sliding the resilient spring with variable resistance to compression, such as spring 262, forward and rearward relative to the rear link 290, the spring may be moved from end to end. Another option is to rotate the resilient spring to provide more or less resistance to compression. In addition, the protrusion 296 may be movable relative to the main portion of the rear link 290 and the spring to obtain more adjustment of the tilt tension. Referring now to FIG. 24, a cross-section of the control mechanism 200 is shown with the protrusion 296 of the rear link 290 and the resilient spring when the back upright 230 is reclined by a userThe spring 262 is engaged and supported thereon. The distance from the fourth pivot 204 to the protrusion 296 is defined by a first distance d₁And (4) showing. In the above-described option, the repositioned protrusion 297 is a new distance d from the fourth pivot 204₂. This type of adjustment affects the relationship between the rear link 290 and the resilient spring 262, thereby providing better adjustability for the user. Alternatively, the spring may be positioned to engage and be actuated by another portion of the control structure 200, such as the back upright 230 or the seat plate 210. All such variations using such springs fall within the scope of the present invention.

When a user is seated in the chair 100, the four-bar control mechanism 200 of the present invention causes the mechanism 200 to be biased forward against the upright stop 205 due to the weight of the user. Therefore, a minimum load is applied to the first and second springs 261 and 262, thereby allowing quick and easy adjustment of the reclining resistance or tilt tension. In combination with the limited movement tension adjustment slider 264 described above, the present invention provides an adjustment mechanism that is easier to locate, operate and utilize, thereby allowing any user of the chair 100 to vary the resistance to recline.

The upright stop 205 is formed by the interface between the control body 260 and the back upright 230. In this embodiment, two rectangular protrusions 244 on the lower back upright 230 provide the stop 205, as shown in fig. 15, and these protrusions 244 fit into rectangular cutouts 270 in the control body 260, as shown in fig. 21. The stop 205 is formed when the top portion of the protrusion 244 engages the top surface of the cutout 270. The position of the stop 205 creates a direct stop wherein the force required to stop the mechanism 200 flows only between the lower portion 251 of the back upright 230 and the control body 260. Thus, the other components of the mechanism 200 need not be designed to provide this force, thereby enabling more economical components and more streamlined assembly.

The seat 100 according to the present invention further comprises a tilt lock 271, the tilt lock 271 being arranged to lock the seat back 110 in the upright position, as shown in figures 16, 25 and 26. The best position to stop the reclining of the seat 100 is away from the actuator of the mechanism 200, in this case the back upright 230. Furthermore, it may be desirable to provide the stop, i.e., the first pivot 201, as far as possible from the reclining pivot point in order to reduce the effect of errors in the contact surface of the stop. In the present invention, the tilt lock 271 is mounted within the control body 260 and is configured to engage and disengage the lower portion 251 of the back upright 230 at a recess 245 formed in the lower portion 251.

In this embodiment, the tilt lock 271 includes a substantially U-shaped tilt lock slide 272, the slide 272 being mounted within the control body 260. The tilt lock slider 272 is connected to a tilt lock lever 273 that protrudes outward from the control body 260 at the side of the seat 100. The lever 273 is pivotally mounted to the control body 260 at pivot 274 in the same manner as pivot 267 for tension lever 266. The lever 273 is then movably connected to the tilt lock slide 272 at contact surface 275 in the same manner that the slide 264 is connected to the tension lever 266 at contact surface 268. In operation, the user moves the tilt lock lever 273 forward to move the locking portion 276 of the tilt lock slider 272 into the tilt lock slot 245 on the control body 260, as shown in phantom in FIG. 25. Accordingly, the back upright 230 is restricted from moving relative to the control body 260, and thus the user cannot recline the chair 100 to remain in the upright position. The user then moves the lever 273 rearward to remove the locking portion 276 from the recess 245 and unlock the seat 100, allowing the user to recline the seat as desired.

As described above, the upright stop 205 limits the forward movement of the seat 100. In the locked configuration the tilt lock 271 limits rearward reclining movement of the seat 100. However, in the unlocked configuration, rearward limit of seat recline movement is provided by a full recline stop that occurs when the recline stop surface 247 on the lower portion 251 of the back upright 230, as shown in fig. 15 and 16, encounters the stop surface 277 on the control body 260, as shown in fig. 21. This blocking limits the reclining movement of the control mechanism 200 to its full range of about 10 degrees.

As shown in fig. 16, in addition to the tension lever 266 and the reclining lock lever 273, the control mechanism 200 includes a height adjustment lever 136 extending outwardly from the control body 260 at the side of the seat within reach of the user. As described above, the height adjustment lever 13 is provided to activate the movable cylinder 133 to raise or lower the seat 120 to a height desired by a user with respect to the floor. The user pulls the height adjustment lever 136 upward toward the user to activate the cylinder 133 while applying weight to the seat 120, thereby lowering the height of the seat 120, or while removing weight to raise the height of the seat 120, as is well known in the art.

While the height adjustment lever 136 functions similarly to the adjustment mechanisms provided on other seats, the pivotal mounting of the lever 136 is unique, improving and simplifying the mounting process. Referring now also to fig. 27-29, the lever 136 is pivotally mounted to the control body 260 at the pivot mounting element 280 using a pivot block 281 and fasteners 282. The lever 136 includes a handle 137, an actuating portion 138, and a mounting portion 139. The mounting portion 139 is formed as an open square with a pair of stubs or bosses 283 extending from the opposing inner side walls 284 toward each other. The pivot mounting element 280 includes a semi-circular groove 285, the semi-circular groove 285 configured to receive the pair of protrusions 283. The pivot block 281 further includes a semi-circular groove 286, the semi-circular groove 286 configured to also receive the pair of protrusions 283. When the lever 136 is mounted to the control body 260, the pair of bosses 283 are sandwiched between the pivot mounting element 280 and the pivot block 281 in a manner that allows the bosses 283 to rotate within the recesses 285 and 286. The pivot mounting element 280 also includes a pair of teeth 287 configured to mate with a pair of notches 288 on the pivot block 281 to simplify alignment and assembly of the components. Alternatively, the protrusion 283 may be provided on the exterior of the mounting portion 139, or a fastening method may be incorporated into the pivot block 281 to further simplify the assembly process.

A spring 289 is provided between the control body 260 and the lever 136 to bias the lever in the unactuated position to bring the actuating portion 138 into contact with the cylinder and to eliminate any vibration or rattling between the lever 136 and the cylinder. Activation of lever 136 as described above requires the user to pivot lever 136 so that when the user releases lever 136, gravity causes lever 136 to return to its unactuated position.

As described above, the pivotal mounting of the lever 136 is achieved by components assembled on the same side of the control body 260, thereby simplifying the assembly process. In this manner, the two pivots on the seat locking lever 150 include similar features, such as the pivot mounting elements 129 and pivot blocks 151, to also simplify the assembly process of the pivot lever. This pivotal mounting arrangement design can be employed in many situations. The main advantages of this pivot joint assembly method and structure are that it can be assembled quickly and easily, and is inexpensive to assemble and efficient to operate.

Still referring to fig. 1 and 4, the chairs 100 and 105 are shown with chair backs 110 and 115, respectively. In addition to the seat height, seat depth, and tilt tension adjustments described above, chairs 100 and 105 according to the present invention also include adjustable back supports in the chair backs 110 and 115. Referring now also to fig. 30-33, the mesh seat back 110 of the seat 100 is shown along with a control mechanism 200. The frame 111 supports the taut and stretched mesh fabric 112. Although a mesh fabric is described, it should be understood that other types of elastic materials may be used in place of the mesh, all of which fall within the scope of the present invention.

In this embodiment, to provide adjustable back support for users of different sizes and with different needs, the present invention provides a tensioning device 160 that can vary the stiffness of the mesh 112 across the back, particularly in the lumbar region, for example. This is different from other mesh back supports in that they typically provide a strong brace or cushion or other member attached to the back 110 or frame 111 in the lumbar region, which can result in a discontinuous pressure gradient applied to the user's back.

The tensioner 160 includes a pair of assemblies 161 mounted on either side of the frame 111. These assemblies 161 comprise three components, namely a front component 162, a rear component 163, and fasteners 164. Although three components are shown, it should be understood that the assembly 161 can have more or fewer components as long as the same functionality is provided. The assembly 161 is secured to a structural member of the frame 111 that guides the movement of the assembly 161 as the assembly 161 moves vertically on the frame 111. The guide feature in this embodiment is a slot 165, the slot 165 also limiting vertical movement of the assembly 161. Alternatively, the guide feature may be a protrusion, and it may extend the entire height of the frame 111.

In this embodiment, the front member 162 is configured with a generally convex front surface 166 and suitable configuration for engaging the rear member 163 and fastener 164. Rear member 163 includes a pair of posts 167, the pair of posts 167 being configured to be positioned within guide slots 165 and received in a rearward configuration of front member 162. Back member 163 also includes a handle 168, handle 167 providing a gripping area for a user when adjusting assembly 161.

The location of the assemblies 161 on the sides of the frame 111 provides improved adjustability and user comfort. As shown in fig. 30, the forward-most point of the assembly 161 is the contact point 166 that is in contact with the mesh 112. The contact points 166 are configured to be located outside the contact area between the user's back and the mesh 112 at the perimeter of the frame 111. The forward-most point 166 of the assembly 161 shortens the effective length of the horizontally oriented web 112. Thus, when a user touches the net 112, the area will not have the same effective length over which to distribute the load applied by the user, resulting in greater tension in the net 112 and greater pressure on the user's back. Since the assemblies 161 do not span the width of the mesh 112, they will naturally distribute tension variations in the vertical and horizontal directions, resulting in a continuous tension gradient in the mesh 112 and, therefore, a continuous pressure gradient on the user's back. The high points of these gradients vary vertically as the assembly 161 moves vertically along the guide slot 165. Since the assemblies 161 are not connected to each other in any way, they can move independently. Thus, the high points of the gradient caused by each assembly 161 need not be at the same height.

Optionally, the high point 166 of the assembly 161 may also be adjustable. This will allow the user to vary the amount of tension present in the mesh 112 and thus vary the pressure on the user's back. Depth adjustment of the assembly 161 also results in a continuous tension gradient across the web 112, further improving the level of adjustment and customization.

Referring now to fig. 34-36, the back frame 116 of the chair back 115 is shown with the fabric and foam pad 117 removed. In this embodiment, the back frame 116 includes a pair of vertical slots 170, and the corrugated support member 171 can be movably mounted to the vertical slots 170. A pair of mounting handles 172 are positioned in the slots 170 from the back side 102 of the frame 116 and are attached to the support member 171 by fasteners 173 or other suitable means. The support member 171 is held in place by friction created by the mounting slots 170 and the handle 172 and lumbar support member 171. The user must grip both handles 172 and overcome the friction force to adjust the support member 171 upward or downward. By using two handles 172 and a slot 170 for guidance, the support 171 will track in a substantially straight direction. The fixed length of the slot 170 also serves as a limit stop for the height adjustment range. The user's back does not rest directly on the support member 171. Instead, a fabric and foam pad 117 (not shown) is present between the user and the support member 171 to provide padding and to assist in a soft transition "feel" between the back and the lumbar region.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. Moreover, the invention is not to be taken as limited to all of these details, and various modifications and substitutions may be made without departing from the spirit or scope of the invention. Further, the embodiments and associated components described herein are manifold, e.g., one or more of these components may be eliminated, or mixed and matched in various combinations, resulting in configurations that are also within the scope of the present invention.

Claims (25)

1. A reclining chair, comprising:

a seat configured to support a user;

a chair back;

a base; and

a control mechanism mounted on the base, the control mechanism connecting the chair back to the seat, the chair back being substantially adjacent to the back of the user when the user is seated on the seat, wherein the control mechanism comprises:

a first resilient member comprising a block formed of a resilient material, the block being under load when a reclining force is applied to the seat back, the first resilient member being configured to resist the reclining force when the first resilient member is compressed;

a downwardly projecting element having an end located above the first resilient member and configured to engage the first resilient member when a reclining force is applied to a seat back such that the first resilient member deforms about the end of the downwardly projecting element when the first resilient member is compressed;

a resistance force adjusting mechanism for changing a resistance force of the first elastic member and being easily operated when the seat is in an upright position; and the resistance adjustment mechanism further comprises a stop that is engaged when a user is seated in an upright position, the stop reducing the load placed on the first resilient member to facilitate convenient operation of the resistance adjustment mechanism; and

a second resilient member configured to return the seat back to the upright position in combination with the weight of the user when the reclining force is removed.

2. The lounge chair of claim 1 wherein said first resilient member has a varying resistance to compression, said resistance adjustment mechanism utilizing said first resilient mechanism's varying resistance to compression in order to vary said control mechanism's resistance to reclining force.

3. The lounge chair of claim 2 wherein operation of said resistance adjustment mechanism moves said first resilient member relative to said downwardly projecting element or moves said downwardly projecting element relative to said first resilient member such that the first resilient member presents a different resistance to compression to the downwardly projecting element resulting in a different resistance to said reclining force.

4. The lounge chair of claim 2 wherein said blocks of resilient material have varying geometric parameters so as to vary the resistance to compression.

5. The lounge chair of claim 2 wherein said blocks of resilient material have varying compression characteristics so as to vary the resistance to compression.

6. The lounge chair of claim 1 wherein said resistance adjustment mechanism includes a first movable member and a second member that is substantially fixed in at least one direction relative to said first movable member and wherein movement of said first movable member relative to said second member by a user changes the resistance of said control mechanism to reclining force.

7. A reclining chair, comprising:

a seat configured to support a user;

a chair back;

a base; and

a control mechanism mounted on the base, the control mechanism connecting the chair back to the seat, the chair back being substantially adjacent to the back of the user when the user is seated on the seat, wherein the control mechanism comprises:

a first resilient member comprising a block formed of a resilient material, the block being under load when a reclining force is applied to the seat back, the first resilient member being configured to resist the reclining force when the first resilient member is compressed;

a downwardly projecting element having an end located above the first resilient member and configured to engage the first resilient member when a reclining force is applied to a seat back such that the first resilient member deforms about the end of the downwardly projecting element when the first resilient member is compressed;

a resistance force adjusting mechanism for changing a resistance force of the first elastic member and being easily operated when the seat is in an upright position; and

a second resilient member configured to return the seat back to the upright position in combination with the weight of the user when the reclining force is removed;

wherein the resistance adjustment mechanism comprises a first movable member and a second member that is substantially fixed in at least one direction relative to the first movable member, and movement of the first movable member relative to the second member by a user changes the resistance of the control mechanism to the reclining force; and

the first resilient member is connected to the first movable member, and movement of the first resilient member relative to the second member varies a resistance of the control mechanism to a reclining force.

8. The lounge chair of claim 7 wherein said first resilient member includes a varying resistance to compression.

9. The lounge chair of claim 1, further comprising a slide mechanism connecting the seat to the control mechanism such that the seat moves slidingly relative to the control mechanism.

10. The lounge chair of claim 9, wherein the slide mechanism further comprises a slide lock operated by a user, the slide lock preventing sliding movement of the seat in the first configuration and allowing sliding movement of the seat in the second configuration.

11. The reclining chair of claim 1, wherein said control mechanism further comprises a tilt lock configured to prevent reclining movement of said seat back from said upright position.

12. The lounge chair of claim 11, wherein the control mechanism further comprises a base member connected to the seat, the chair back comprising a back upright member and a back support member, the back support member connected to the back upright member, the back upright member pivotally connected to the base member, the tilt lock preventing pivotal movement of the back upright member relative to the base member.

13. The reclining chair of claim 1, wherein the chair back includes a back upright member and a back support member, the control mechanism further comprising a base member pivotally connected to the back upright member, wherein the back upright member is pivotally connected to the back support member at a rear joint, the rear joint including a preloaded resilient member that facilitates continuous engagement of the back support member and the back of the user during reclining of the chair.

14. The lounge chair of claim 13 further comprising a pair of spaced apart rear joints positioned relative to said control mechanism to substantially reduce shear forces on a user's back during reclining of the chair.

15. The reclining chair of claim 1, wherein said seat back further comprises a back-support adjustment mechanism configured to vary the stiffness of said seat back.

16. The reclining chair of claim 15, wherein said chair back further comprises a frame and a resilient material mounted on said frame, said back-support adjustment mechanism varying the stiffness of said resilient material.

17. The reclining chair of claim 15, wherein said seatback support adjustment mechanism varies rigidity in a lumbar region of said seat back.

18. A reclining chair, comprising:

a seat configured to support a user;

a chair back;

a base; and

a control mechanism mounted on the base, the control mechanism connecting the chair back to the seat, the chair back being substantially adjacent to the back of the user when the user is seated on the seat, wherein the control mechanism comprises:

a first resilient member comprising a block formed of a resilient material, the block being under load when a reclining force is applied to the seat back, the first resilient member being configured to resist the reclining force when the first resilient member is compressed;

a downwardly projecting element having an end located above the first resilient member and configured to engage the first resilient member when a reclining force is applied to a seat back such that the first resilient member deforms about the end of the downwardly projecting element when the first resilient member is compressed;

a resistance force adjusting mechanism for changing a resistance force of the first elastic member and being easily operated when the seat is in an upright position; and

a second resilient member configured to return the seat back to the upright position in combination with the weight of the user when the reclining force is removed;

the base includes a central axis, the seat back includes a pivot member and a back support member, the control mechanism includes a four-bar mechanism having a base member to which the pivot member is pivotally connected at a pivot point forward of the central axis, and a back support member to which the pivot member is pivotally connected at a rear pivot, such that a reclining force applied by a user to the seat back causes the seat back to move rearward, causing the pivot member to pivot about the pivot point relative to the base member, and causing the back support member to pivot about the rear pivot, the back support member remaining substantially in contact with the back of the user due to reduced shear and pull-away forces.

19. A reclining chair, comprising:

a seat back including a back support member and a pivot member;

a seat having a front portion and a rear portion;

a base having a center post with a substantially vertical center axis; and

a control mechanism mounted on the base, the control mechanism connecting the chair back to the seat;

the control mechanism is configured as a four-bar mechanism including a base member and the pivot member extends under the front and rear portions of the seat so as to be pivotally connected to the base member at a pivot point forward of the central axis, the pivot member being pivotally connected to the back support member at a rear pivot point and to the front portion of the seat at a position forward of the pivot point;

thus, the reclining force applied by the user to the chair back causes the chair back to move rearwardly and the seat to rise, causing the pivot member to pivot relative to the base member about the pivot point and the back support member to pivot about the rear pivot.

20. The lounge chair of claim 19, wherein the seatback support member remains in substantial contact with the user's back when the user applies a reclining force to the chair back.

21. The reclining chair of claim 19, wherein said seat serves as a connector to a pivot member within said four-bar mechanism, wherein said control mechanism further comprises a follower connected to said seat and said base member such that pivotal movement of said pivot member causes movement of said seat relative to said base member.

22. The lounge chair of claim 19 wherein said rear pivot includes a resilient member.

23. The reclining chair of claim 19, wherein said control mechanism further comprises a resistance adjustment mechanism for varying the resistance of said control mechanism to the reclining force applied by the user to the chair back, said resistance adjustment mechanism being readily operable by the user when the user is in the upright position.

24. The lounge chair of claim 23 wherein said resistance adjustment mechanism includes a first movable member and a second member that is substantially fixed in at least one direction relative to said first movable member, movement of said first movable member relative to said second member by a user varying the resistance of said control mechanism to reclining force.

25. A reclining chair, comprising:

a seat configured to support a user;

a chair back;

a base; and

a control mechanism mounted on the base, the control mechanism connecting the chair back to the seat, the chair back being substantially adjacent to the back of the user when the user is seated on the seat, wherein the control mechanism comprises:

a first resilient member comprising a block formed of a resilient material, the block being under load when a reclining force is applied to the seat back, the first resilient member being configured to resist the reclining force when the first resilient member is compressed;

a downwardly projecting element having an end located above the first resilient member and configured to engage the first resilient member when a reclining force is applied to a seat back such that the first resilient member deforms about the end of the downwardly projecting element when the first resilient member is compressed;

a resistance force adjusting mechanism for changing a resistance force of the first elastic member and being easily operated when the seat is in an upright position; and

a second resilient member configured to return the seat back to the upright position in combination with the weight of the user when the reclining force is removed;

wherein the resistance adjustment mechanism is adapted to change the resistance of the first elastic member to the reclining force by changing the relative positions of the first elastic member and the end of the downward projecting member.