GB2547680A

GB2547680A - Moving chair

Info

Publication number: GB2547680A
Application number: GB1603307.8A
Authority: GB
Inventors: Read David; Farrer Ralph
Original assignee: Herman Miller Ltd
Current assignee: Herman Miller Ltd
Priority date: 2016-02-25
Filing date: 2016-02-25
Publication date: 2017-08-30
Also published as: GB201603307D0

Abstract

A chair comprising a frame with an elongate rail member 470 and a first bearing element 480 coupled to it wherein the elongate rail member 470 has a transverse portion 472 projecting outward from the rail member 470 and the bearing element 472 covers a portion of the rail member 470 and has a hole into which the transverse portion 472 extends and a seat bottom which can slide on the bearing 480. Also disclosed is a pivot joint comprising a pin, a projection on a first body with a hole to receive the pin, an insert with a hole for receiving the pin such that the projection can pivot about the pin wherein the insert, pin and projection are received in a recess on a second body. The seat may have second bearing elements and convex and concave surfaces may be used. A spring 490 may be attached to the transverse projection 472 to bias the seat to a position.

Description

MOVING CHAIR

FIELD OF INVENTION

The present invention relates to a moving chair, more particularly to a chair having moveable components, such as a moveable seat bottom and/or a pivotable seat back.

BACKGROUND

For a comfortable or ergonomic chair, it can be advantageous if the seat back may pivot relative to the seat bottom, allowing the user to recline to some degree. In some types of chair having a single-point pivot, the seat back may pivot relative to the seat bottom, the pivot being located at or approximately level or below with the seat bottom. This is good but may place requirements on the pivot joint. The seat back may carry a non-negligible portion of the sitter’s weight, particularly when reclined, and all of this needs to be transmitted through the pivot.

Alternatively, the seat back may be supported the part way up, by being pivoted at or around its midpoint. The seat back pivots about its approximate midpoint held on a pivot by a frame piece of the chair. The disadvantage of this is that, as the upper part of the seat back rotates backward, the lower part rotates forward, possibly interfering with a sitter’s lower body, requiring for them to sit slightly forward in the chair for comfort.

One potential solution to this problem is described in US 6,722,735 B2 of Lucci et al, wherein a chair has a chair frame and a synchronously moving seat bottom and seat back interconnected by a flexible intermediate portion and formed as one-piece moulded plastic shell, the seat bottom being slidably mounted to support members in the chair frame and the seat back and being pivotably engaged to a transverse tubular support member of the chair frame. When used by a sitter, it moves with the sitter’s body such that, when the sitter is sitting upright, the seat back is in an upright position and the seat bottom slid to a rearward position. When the user is reclined, the seat back is rotated to a reclined position and the seat bottom slid to a forward position. The extension of the seat bottom and the rotation of seat back causes deformation of the flexible intermediate portion between the seat back and seat bottom from its original configuration, thereby placing this portion in tension. This tension causes the seat to return to its upright position when unoccupied or when the user of the chair removes pressure from the seat back. The resilience of the seat causes it to rebound to the original position without the use of any mechanical devices.

Several solutions to pivotably mounting the seat back on the frame are described in US 6,722,735 B2. In one embodiment, the seat back includes outwardly extending hooks on its rear surface, wherein the hooks engage with the tubular transverse member of the chair frame, either being supported on or snap-fitting to the tubular transverse member. In another alternative, a mounting pad mounted on or integral to the seat back, the mounting pad defining a recess for snap-fitting on to the tubular transverse member. To allow the seat bottom to move forward and backward, the frame is provided with frame rails. The seat bottom moves relative to the frame via a slide block having a channel extending therethrough and mounted on or integral to the underside of the seat bottom, with bushings inserted into the channel, engaging with the slide block and providing bearing surfaces to reduce friction as the seat bottom slides along the frame rails. The frame rail has front and rear stops in the form of cylindrical members extending outward from the frame rails for limiting the travel of the seat bottom relative to the frame rails, the front stop extending downward from the underside of the frame rail and engaging the lower portion of the slide block and the rear stop extending upward from the topside of the frame rail and engaging the upper portion of the slide block.

In use, the seat back reclines as the seat bottom slides forward. The extension of the seat bottom and the rotation of seat back causes deformation of the flexible intermediate portion between the seat back and seat bottom from its original configuration, thereby placing this portion in tension. This tension causes the seat to return to its upright position when unoccupied or when the user of the chair removes pressure from the seat back. The resilience of the seat causes it to rebound to the original position without the use of any mechanical devices.

BRIEF SUMMARY OF THE INVENTION

Aspects of this disclosure relate to a chair with frame including a sliding joint having a seat bottom slidable relative to an elongate rail member of the frame on a first bearing element coupled to the elongate rail member, the elongate rail member including a transverse projection extending outward from the elongate rail member in a direction substantially transverse to the direction in which the elongate rail member extends, the first bearing element covering a portion of the least one elongate rail member and having a hole into which the transverse projection of the elongate rail member extends. A chair with frame also includes a seat back pivotably mounted to the frame by a pivot joint comprising: a pin; a projection on a first body such as the seat back, the projection having a hole extending therethrough for receiving the pin; an insert having a hole extending therethrough for receiving the pin; and a recess on a second body such as the frame, the recess being configured to receive the insert and permit pivotable movement of the projection about the pin with the insert, pin and projection located within the recess. The inclusion of this sliding mechanism together with this pivot joint provides a synergistic advantage in terms of ease of assembly and manufacture, due to the simultaneous inclusion of multiple joints in the mechanism by which the seat back and seat bottom move relative to the frame. This is particularly evident when the seat back and seat bottom are formed of a single piece or otherwise mechanically linked.

According to a first aspect, there is provided a chair comprising: a frame including an elongate rail member and a first bearing element coupled to the elongate rail member, the elongate rail member including a transverse projection extending outward from the elongate rail member in a direction transverse to the direction in which the elongate rail member extends, the first bearing element covering a portion of the least one elongate rail member and having a hole into which the transverse projection of the elongate rail member extends; a seat bottom slidable relative to the elongate rail member of the frame on the first bearing element; and a seat back pivotably mounted to the frame by a pivot joint to permit pivotable movement of the seat back relative to the frame, the pivot joint comprising: a pin; a projection on a first body, the projection having a hole extending therethrough for receiving the pin; an insert having a hole extending therethrough for receiving the pin; and a recess on a second body, the recess being configured to receive the insert and permit pivotable movement of the projection about the pin with the insert, pin and projection located within the recess. Thus slide and pivot joints are provided, allowing the seat bottom to slide and the seat back to pivot relative to the frame. The transverse projection of the elongate rail member serves to axially locate and fix the first bearing element relative to the elongate rail member while simultaneously providing an attachment point for other components.

Preferably, the hole through the insert includes a narrowing defining a first location on one side of the narrowing and a second location on the other side of the narrowing, the pin being positionable within the hole in either location, the narrowing of the hole resisting the change in position of the pin. This way the pin may be in either location of the hole but does not easily slip between them - a deliberate force is required to overcome the resistance. In the absence of such a force, the pin remains in place. The shape of the hole may be a ‘stadium’ shape, modified by a central narrowing, i.e. such that the minor diameter is reduced, tending toward the outline of a figure-of-eight shape. The narrowing can also be described as one or more ridges or bumps extending into the hole from the periphery of the hole to define multiple locations.

Preferably, the pin includes a circumferential groove and the insert includes a protuberance extending outward from the inner surface of the hole at the first location to extend into the circumferential groove of the pin when the pin is positioned in the first location of the hole. In doing so, the pin is axially retained at a desired axial location when in the first location - it is prevented from slipping axially out. This provides assembly advantages as the pivot joint pieces can be assembled step-by-step without fear of accidentally undoing steps through careless handling.

Preferably, the pin includes a circumferential ridge at one end that is larger than the insert-hole first and second locations so that the pin is insertable into the hole of the insert with the non-ridged end only. Since the pin is insertable only one way, it is easier to assemble.

Preferably, the insert is insertable into the recess with the pin and projection when the pin is positioned in the first location of the hole of the insert and, following the inserting of the insert, application of force between insert and the second body causes movement of the pin from the first location to the second location of the hole of the insert. In the second location, the pin is no longer retained axially by the protuberance of the first location of the hole of the insert.

Preferably, retention members located on the insert engage with corresponding portions of the recess to retain the insert in the recess when the insert is inserted into the recess and the pin is positioned in the second location of the hole of the insert. This way the freeing of the pin coincides with the retention of the insert in the recess. The retention members may be male or female portions located on the insert designed to snap-fit to female/male portions of the insert. They may extend substantially in the same direction as the pin axis, i.e. normal to the direction of insertion of the insert/projection/pin assembly.

Preferably, the insert includes an arm, the hole extending through the arm. The arm may entirely surround the hole or in alternative embodiments, a cut-out portion may link the hole interior with the exterior of the insert. This may make the arm portions adjacent the hole less stiff and easier to position the pin between locations.

Preferably, the insert includes two arms each having holes extending therethrough for receiving the pin, the two holes each having axially aligned first and second locations, the two arms being spaced from each other to admit the projection of the first body between the arms.

Preferably, the pin comprises a plurality of axially distinct portions of different widths, the widths of the holes of the first and second arms being different to provide that the pin is insertable into the insert from only one side of the insert.

Preferably, the recess is located on the frame and the projection of the pivot joint is located on the seat back.

Preferably, the frame comprises an elongate back support member for supporting the seat back, the elongate member extending from a left side of the chair to a right side of the chair from the perspective of a user occupying the chair, the seat back being pivotably mounted on the elongate back support member.

Preferably, the chair comprises a plurality of pivot joints between the seat back and the frame, such as two pivot joints.

Preferably, the seat bottom comprises a second bearing element for slidable engagement with the first bearing element. This provides improved support for the seat bottom without compromising the smoothness of the slide.

Preferably, the first bearing element has a convex cross section normal to the direction of slidable movement and the second bearing element has a concave cross section normal to the direction of slidable movement. This way, unwanted transverse movement of the seat bottom relative to the frame is prevented.

Preferably, the elongate rail member has a circular cross section and the first bearing element has a ‘C’-shaped cross section extending around a portion of the circumference of the elongate rail member.

Preferably, the first bearing element extends at least 180s around the circumference of the elongate rail member.

Preferably, the first bearing element is configured to snap-fit to the elongate rail member.

Preferably, the chair includes two elongate rail members each having coupled thereto a respective first bearing element.

Preferably, the hole in the first bearing element is a through hole and the transverse projection extends through the through hole in the first bearing element.

Preferably, wherein the seat bottom comprises at least one stop projecting outward from the seat bottom to engage with the transverse projection of the elongate rail member at a particular displacement of the seat bottom relative to the elongate rail member to limit the slidable range of the seat bottom relative to the elongate rail member.

Preferably, the seat bottom comprises two stops projecting outward from the seat bottom, each engaging with the transverse projection of the elongate rail member at a different displacement of the seat bottom relative to the elongate rail member and defining two bounds between which the seat bottom is slidable relative to the elongate rail member.

Preferably, the chair is configured to provide a biasing force to the seat bottom when displaced from an equilibrium position.

Preferably, the chair is configured to bias the seat bottom to one end of the slidable range.

Preferably, the chair comprises a spring coupled to the transverse element and to the seat bottom, the spring providing a biasing force to the seat bottom.

Preferably, the chair comprises at least one elastomeric band, the at least one elastomeric band providing a biasing force to the seat bottom. The elastomeric band may connect to the transverse element and provide a force between it and a boss or lug extending from the seat bottom around which the elastomeric band extends. A single elastomeric band may connect to two transverse projections of elongate rail members and extend around a boss or lug or other projection extending outward of the seat bottom.

Preferably, the chair is configured such that, when the chair in place on a horizontal floor, the elongate rail is inclined to the horizontal, such that gravity provides a biasing force to the seat bottom.

Preferably, the seat back and seat bottom comprise portions of a one-piece shell.

Preferably, the seat bottom and seat back are configured to move synchronously relative to the frame. In doing so, the seat back pivots back and the seat bottom slides forward at the same time.

While preferred embodiments of the chair include the specified sliding mechanism and pivot joint described above, further aspects of this disclosure may allow for the sliding mechanism to be incorporated without the pivot joint, or the pivot joint to be incorporated without the sliding mechanism. Depending on the application, either a different sliding mechanism or pivot joint not described herein is used to accompany the pivot joint or sliding mechanism, or the pivot joint or sliding mechanism is used by itself without an accompanying sliding mechanism/pivot joint.

According to a second aspect, there is provided a chair comprising: a frame including an elongate rail member and a first bearing element coupled to the elongate rail member, the elongate rail member including a transverse projection extending outward from the elongate rail member, the first bearing element covering a portion of the least one elongate rail member and having a hole into which the transverse projection of the elongate rail member extends; a seat bottom slidable relative to the elongate rail member of the frame on the first bearing element; and a seat back pivotably mounted to the frame by a pivot joint to permit pivotable movement of the seat back relative to the frame. Therefore this chair includes the sliding mechanism of the first aspect but not the pivot joint. The chair may optionally include any of the preferred features discussed above.

According to a third aspect, there is provided a chair comprising: a frame; a seat bottom slidable relative to the frame; and a seat back pivotably mounted to the frame by a pivot joint to permit pivotable movement of the seat back relative to the frame, the pivot joint comprising: a pin; a projection on a first body, the projection having a hole extending therethrough for receiving the pin; an insert having a hole extending therethrough for receiving the pin; and a recess on a second body, the recess being configured to receive the insert and permit pivotable movement of the projection about the pin with the insert, pin and projection located within the recess. Therefore this chair includes the pivot joint of the first aspect but not the sliding mechanism. The chair may optionally include any of the preferred features discussed above.

According to a fourth aspect, there is provided a pivot joint comprising: a pin; a projection on a first body, the projection having a hole extending therethrough for receiving the pin; an insert having a hole extending therethrough for receiving the pin; and a recess on a second body, the recess being configured to receive the insert and permit pivotable movement of the projection about the pin with the insert, pin and projection located within the recess.

According to a fifth aspect, there is provided a method of assembly of a pivot joint as described herein, the pivot joint comprising a pin, a projection on a first body, the projection having a hole extending therethrough for receiving the pin, an insert having a hole extending therethrough for receiving the pin, a recess on a second body, the recess being configured to receive the insert and permit pivotable movement of the projection about the pin with the insert, pin and projection located within the recess, the method comprising: inserting the pin into the hole of the projection of a first body and into the hole of the insert so that the pin occupies a first location of the hole of the insert; moving the insert relative to the pin to transfer the pin to a second location of the hole of the insert; inserting the insert, pin and projection into the recess; and, with the insert pin and projection located in the recess, moving the insert relative to the pin and second body to transfer the pin to the first location of the hole of the insert. The pin may be axially retained in the insert and projection holes when in the second position to ease assembly. The recess may be configured to receive one or both ends of the pin in guiding means such as slots to locate the pin relative to the second body. Moving the insert relative to the pin and second body to transfer the pin to the first location of the hole of the insert may cause the insert to engage with the engagement means of the recess, such as ‘male’ protuberances or ‘female’ internal recesses. This may be in, for example, a snap-fit manner. This may then retain the insert in such a position relative to recess, the ends of the pin being retained in their location along the guiding means by the sides of the hole of the insert. The projection on the first body may then rotate relative to the second body about the axis of the pin.

Such a pivot joint may find application outside of the field of furniture. Equally, such a sliding mechanism described herein may be applied outside of the field of furniture. For example, the sliding mechanism may be used to facilitate sliding motion of two arbitrary bodies relative to each other. The pivot joint may be used to pivotable motion of two arbitrary bodies relative to each other. Preferably the pivot joint and sliding mechanism are incorporated into an item of furniture, more preferably said item of furniture is a chair. Other suitable applications are envisaged and will be readily apparent to the skilled person.

BRIEF SUMMARY OF THE DRAWINGS

The invention will be described in more detail by way of example with reference to the accompanying drawings, in which:

Figure 1 is a view of a chair embodying an aspect of the invention in two configurations;

Figure 2 is an oblique, semi-exploded view showing components of a pivot joint embodying an aspect of the invention;

Figure 3 is a side view of a ‘clip’ component of a pivot joint embodying an aspect of the invention;

Figure 4 is another side view of the ‘clip’ component of a pivot joint embodying an aspect of the invention from the other side;

Figure 5 is a cross-sectional view through the ‘clip’ component of a pivot joint embodying an aspect of the invention;

Figure 6 is a side view through a ‘pin’ component of a pivot joint embodying an aspect of the invention;

Figure 7 is a cross-sectional view of a pivot joint embodying an aspect of the invention at a first intermediate stage of its assembly;

Figure 8 is a cross-sectional view of the pivot joint of Figure 7 at a second intermediate stage of its assembly;

Figure 9 is a front view of a ‘recessed body’ component of a pivot joint embodying an aspect of the invention;

Figure 10 is a sectional view through the recessed body component of Figure 9;

Figure 11 is a side view of a ‘projection’ component of a pivot joint embodying an aspect of the invention;

Figure 12 is an oblique, exploded view of components of a sliding mechanism embodying an aspect of the invention;

Figure 13 is a sectional view of a cylindrical rail and pin of a sliding mechanism embodying an aspect of the invention;

Figure 14 is a cutaway view through a seat bottom embodying an aspect of the invention;

Figure 15 is two side views of a sliding mechanism embodying an aspect of the invention at either extremity of its permitted movement range;

Figure 16 is an underside view of a seat bottom including two sliding mechanisms embodying an aspect of the invention;

Figure 17 is an underside view of an alternative seat bottom including two sliding mechanisms embodying an aspect of the invention;

Figure 18 is an underside view of an alternative bearing assembly embodying an aspect of the invention;

Figure 19 is an isometric view of a ‘capsule’ component of the alternative bearing assembly of Figure 18;

Figure 20A is an isometric view of the bearing channel of the assembly of Figure 18; and Figure 20B is a chair-underside view of the bearing channel of Figure 20A.

DETAILED DESCRIPTION OF THE INVENTION

Example chairs and portions thereof embodying aspects of the invention will now be described with reference to Figures 1 to 20B.

In Figure 1, a chair 10 is shown embodying multiple aspects of the invention, the chair comprising a frame 30 having four legs, two extending in the direction of a ground on either side of a moulded shell 20 comprising a seat bottom and a seat back formed as an integral piece. The frame supports the seat bottom of the moulded shell 20 on a slideable joint 50, of which further details are provided below, such that the seat bottom may slide forward and backward relative to the frame. The front legs are joined on each side to the respective back legs by an arm rest extending above the height of the seat bottom. The arm rests are also joined at the back of the chair by a transverse back support beam, to which the seat back of the moulded shell 20 is pivotably mounted by a pivot joint 40, of which further details are provided below. The seat back may be pivotably mounted on one, two or more than two pivot joints as described herein. To allow the seat back to pivot and seat bottom to slide in a synchronous manner, the moulded shell 20 is sufficiently flexible for the seat back to pivot relative to the seat bottom. Attached to the upper surface of the seat bottom is a cushion assembly 60 attached by means that are described in further detail below. Figure 1 also shows a chair 10’ in a second configuration, wherein the seat back and seat bottom are moved relative to the frame 30. In the first configuration, the left chair 10, has an upright seat back and the seat bottom is slid to the rear of its slidable range. In the second configuration, the chair 10’ has a seat back that is reclined and the seat bottom is slid to the front of its slidable range. The seat back and seat bottom may occupy any intermediate position within a permitted range to achieve desired comfort. Example materials from which moulded shell 20 comprising the seat back and seat bottom may be made include plastics materials such as ABS (acrylonitrile butadiene styrene), PP (polypropylene), & FIDPE (high-density polyethylene), glass fibre materials, carbon fibre materials, metal materials and combinations thereof. Example materials from which the chair frame 30 may be made include metal materials and plastics materials. As an example, the chair frame 30 may be made largely from tubular steel, with certain portions moulded from plastics materials.

While Figure 1 shows an example chair with four legs, the invention is not limited to embodiments with four legs. For example, the chair may be in ‘sled’ configuration having two front legs and omitting any rear legs, wherein a ‘U’ shape extends from the bottom of the front legs underneath the seat bottom, ‘U’ shape supporting the front legs in an upright position and the chair being cantilevered by the front legs. Alternatively the chair may be in a ‘pedestal’ configuration, comprising a pivot mount beneath the chair frame that supports the seat bottom and a plurality of legs extending outward beneath the pivot mount, the seat bottom and seat back being rotatable relative to the plurality of legs extending out beneath the pivot mount.

Figure 2 shows selected components of a pivot joint 200 embodying an aspect of the invention. Figure 2 shows a projection 210, a pin 230 and a clip 250. Not shown in Figure 2 but also part of the pivot joint is a recessed body 280. The pivot joint 200 allows pivotable movement of the projection 210 relative to the recessed body 280. As part of the pivot joint 200, a projection 210 extends outward from the back surface of the seat back and has a hole 212 extending through the projection from one side to another. The pivot joint 200 further comprises a clip 250 that has a first arm 260 and a second arm 270 extending upward from a base. The two arms 260, 270 and the base of the clip 250 define a cavity for receiving the projection 210 and allowing pivotable movement of the projection 210 relative to the clip 250.

Figure 3 shows the first arm 260 of the clip 250 in more detail. A first elongate hole 262 of extends through the first arm 260. The first elongate hole 262 has a vertically aligned ‘stadium’ shape, having the form of a rectangle with semicircles of diameter D1 on upper and lower sides and, from one side of the stadium shape a small projection 264 extends into the stadium shape, partitioning the hole 262 into an upper portion 263 and a lower portion 265.

Figure 4 shows the second arm 270 of the clip 250 in more detail. A second elongate hole 272 of extends through the second arm 270. The second elongate hole 272 has also vertically aligned ‘stadium’ shape having the form of a rectangle with semicircles of diameter D2 on upper and lower sides and, from one side of the stadium shape, a small projection 274 extends into the stadium shape, partitioning the hole 272 into an upper portion 273 and a lower portion 275.

The first and second elongate holes 262, 272 are aligned with each other to receive the pin 230, wherein the pin may occupy either the upper portions 263, 273 or the lower portions 265, 275 of the first and second elongate holes 262, 272. The projections 264, 274 of the elongate holes 262, 272 retain the pin 230 in one either the upper portions 263, 273 or lower portions 265, 275, but the pin may be moved over the projections 264, 274 and therefore between the upper portions 263, 273 and lower portions 265, 275 on application of sufficient force to cause a temporary deformation of the arms 260, 270 and/or the pin 230.

Figure 5 shows a cross-sectional view through the clip 250, the sectional view intersecting with both elongate holes 262, 272. The cavity for receiving the projection can be seen between the first arm 260 and second arm 270. The second elongate hole 272 has a constant profile with depth but the first elongate hole 262 is not constant with depth. At the side of the first elongate hole 262 facing the second arm 270, the diameter of upper portion 263 is reduced by inward rim projection 266, which is used to axially locate the pin 230 when inserted into the first and second elongate holes 262, 272 and located in the upper portions 263, 273 of the first and second elongate holes 262, 272. The inward rim projection 266 is also visible in Figure 3 which shows the detail of the first arm 260.

Figure 6 shows a side-view of the pin, the pin being rotationally symmetrical about its axis, the pin having four portions of different diameters, the first (left-most) portion 232 having a diameter D3, the second portion 234 having a diameter that is less than the diameter D3 of the first portion, the third portion 236 having a third diameter that is greater than the diameter D3 of the first portion 232, and the fourth (right-most) portion 238 having a diameter D4 that is greater than the diameter of the third portion 236.

The diameter D1 of the first elongate hole 262 in the first arm 260 is greater than the diameter D3 of the first portion 232 of the pin 230 but less than the diameter D4 of the fourth portion 238 of the pin 230. The diameter D2 of the second elongate hole 272 in the second arm 270 is greater than the diameter D4 of the fourth portion of the pin 230. This means that the pin 230 is only able to be fully inserted in one direction into the first and second elongate holes 262, 272, i.e. from the second arm 270 and with the first portion 232 first. The inward rim projection 266 is sized to reduce the diameter locally to less than the diameter D3 of the first portion 232, extending into the groove corresponding to the second portion 234 of the pin 230 that has a reduced diameter compared to the first and third portions 232, 236. Since the inward rim projection 266 of the first elongate hole 262 reduces locally the diameter of the upper portion 263 of the first elongate hole 262, the pin 230 may not be fully inserted into the first and second elongate holes 262, 272 in the upper portions 263, 273 but must instead be inserted into the lower portions 265, 275. When it is desired for the pin 230 to be located in the upper portions 263, 273, then it may be forced past the projections 264, 274 to move from the lower portions 265, 275 to the upper portions 263, 273, provided the pin 230 is axially located in the elongate holes 262, 272 such that the second portion 234 of the pin 230 may receive the inward rim projection 266 of the upper portion 263 of the first elongate hole 262.

Figure 7 shows a cross-sectional view of the projection 210, pin 230 and clip 250 combined at an intermediate step of the assembly of the pivot joint 200. The clip 250 is placed over the projection 210 such that the hole 212 is aligned with the lower portions 265, 275 of the first and second elongate holes 262, 272 of the clip 250. The pin 230 is then inserted, first portion 232 first, through the second elongate hole 272, the hole of the projection 212, and the first elongate hole 262 until the second portion 234 of the pin 230 is axially aligned with the face of the first arm 260 that faces the second arm 270, i.e. with the inward rim projection 266 of the first elongate hole.

Figure 8 shows a cross-sectional view of the projection 210, pin 230 and clip 250 combined at a subsequent intermediate step of the assembly of the pivot joint 200. From the configuration shown in Figure 7, the clip 250 is pulled downward relative to the pin 230 and projection 210, such that the pin 230 passes over the projections 264, 274 of the first and elongate holes that separate the upper portions 263, 273 and lower portions 265, 275 and is subsequently held in the upper portions 263, 273, the inward rim projection 266 engaging with the groove in the pin corresponding to the reduced diameter at the second portion 234.

The temporary assembly of projection 210, pin 230 and clip 250 shown in Figure 8 may then be inserted into the recessed body 280 and retained within the recessed body such that the projection 210 is pivotable about the pin 230 relative to the clip 250 and recessed body 280.

Figure 9 shows a front view of a portion of the recessed body 280 shown in Figure 8 may be inserted. The recessed body 280 includes a recess into which the temporary assembly of projection 210, pin 230 and clip 250 may be inserted. The length of the pin is greater than the distance between the outer faces of the first and second arms 260, 270 so the first and fourth portions 232, 238 extend beyond the outer faces of the first and second arms 260, 270. The recess includes guide channels 282, 284 than narrow in width from the mouth of the recess toward the back, to the extent that, at the back of the recess, the width of the first guide channel 282 is substantially the same as that of the first portion 232 of the pin 230 and the width of the second guide channel 284 is substantially the same as that of the fourth portion 238 of the pin 230, so that the pin 230 may be supported on each side by the guide channels 282, 284 when inserted into the guide channels 282, 284.

Figure 10 shows a sectional view through the recessed body 280 in which the guide channel 282 is seen to reduce in width from the mouth of the recess toward the back of the recess. The recess extends from front 288 to back 286 of the recessed body 280 across the lower half of the recessed body 280, so that the first and second sides of the recessed body 280 are joined only at the upper half. Figure 10 shows an upward-extending cavity in recessed body 280 between the first and second guide channels 282, 284, the further cavity being obscured by the front 288 of the recessed body 280 in Figure 9. The upward-extending cavity includes a rear wall 292 on the side of the upward-extending cavity adjacent the rear 286 of the recessed body 280, and a front wall 294 on the side of the upward-extending cavity adjacent the front 288 of the recessed body 280. From the rear wall 292 is a continuation of the front-facing rear wall 290 of the recess that is visible in Figure 9.

To assemble the pivot joint 200, the assembly of projection 210, pin 230 and clip 250 shown in Figure 8, in which the pin 230 occupies the upper portions 263, 273 of the first and second elongate holes 262, 272 of the first and second arm 260, 270, is combined with the recessed body 280. The first and fourth portions 232, 238 of the pin 230 extend outward of the outermost faces of the first and second arms 260, 270 of the clip 250. The assembly is slid into the recess wherein the first portion 232 of the pin slides into the first guide channel 282 and the fourth portion 238 of the pin slides into the second guide channel 284 until the ends of the pin 230 reach the rear of the guide channel. At this point, the assembly of projection 210, pin 230 and clip 250 is located sufficiently far back in the recess that the uppermost first and second arms are adjacent the upward-extending cavity in the recessed body 280.

To secure together the components of the pivot joint 200, the clip 250 is pushed upward from below relative to the recessed body 280. The ends of the pin 230 are retained in the guide channels 282, 284 of the recessed body 280 and so are unable to move with the clip 250. The clip 250 moves upward so that the first and second arms 260, 270 extend into the upward-extending cavity. At the same time, the pin 230 moves from the upper portions 263, 273 of the first and second elongate holes 262, 272, across the projections 264, 274 and into the lower portions 265, 275.

The clip 250 is therefore retained in the recessed body 280 by the arms 260, 270 bearing against the front wall 294 of the upward-extending cavity, therefore preventing the projection 210, pin 230, and clip 250 from sliding out of the recessed body 280 along the guide channels 282, 284. The projections 264, 274 of the first and second elongate holes 262, 272 prevent the pin 230 from moving to the upper portions 263, 265 of the first and second elongate holes 262, 272, thereby disengaging the first and second arms 260, 270 from bearing against the front wall 294 of the upward-extending cavity.

In addition, the outward-extending faces of the arms 260, 270 of the clip are provided with outward-extending projections 268, 278 at the uppermost point of the arms 260, 270. When the clip 250 pushed upward such that the pin 230 occupies the lower portions 265, 275 and the arms 260, 270 engage with the front wall 294 of the upward-extending cavity, the outward-extending projections 268, 278, engage with side-wall recesses 296, 298 in the side walls of the upward-extending cavity, providing a further protection against the clip 250 moving relative to the recessed body 280.

When assembled in this fashion, the projection 210 is free to rotate about the pin 230 between the arms 260, 270, rotating relative to the clip 250 and recessed body 280, thus providing the pivoting functionality to the pivot joint 200. Pivot joints 200 as described herein may be particularly applicable to chairs as described herein.

Chairs embodying aspects of the invention may include one or more of the above-described pivot joints 200. For example, the chair shown in Figure 1 may comprise one or more pivot joints 200, wherein the transverse back support beam comprises the recessed body 280 and the projection 210 extends outward from the rear of the seat back portion of the moulded shell 20. In particularly preferred embodiments, the chair may comprise two such pivot joints. For example, Figure 11 shows a portion of the moulded shell 20 in cross sectional side view, with the 210 extending outward from it, the hole 212 through the projection 210 being visible.

Figure 12 shows in an oblique, exploded view components of a sliding mechanism 400 embodying an aspect of the invention. The sliding mechanism 400 may enable sliding movement of a seat bottom of chair relative to the frame of a chair. In Figure 8, the lower surface 410 of the seat bottom, i.e. the surface of the seat bottom furthest from the user of the chair when occupied, comprises a number of features extending outward from it that form the chair-bottom-side portion of the sliding mechanism 400. A bearing channel 430 is mounted on the lower surface 410 of the seat bottom via a mount 420. The bearing channel is in the form of an elongate channel having a concave curved cross-sectional profile, to mate with and slidably move along a cylindrical bearing. A cylindrical rail 470 forming part of the chair frame has extending radially outward from it a pin 472. A shim clip 480 in the form of an elongate cylindrical shell portion having a C-shaped cross section may clip to the cylindrical rail, the shim clip 480 extending more than 180s around the cylindrical rail 470 to securely clip to the cylindrical rail 470. A boss 482 formed on the outer surface of the shim clip has extending through it a through hole 484. When the shim clip 480 is clipped to the cylindrical rail 470, the pin 472 of the cylindrical rail 470 extends through the through hole 484 of the shim clip, the additional material of the boss 482 providing increased strength in the neighbourhood of the through hole 484.

Figure 13 shows a cutaway view normal to the axis of the cylindrical rail 470 through the pin 472, the cylindrical rail 470 shown as a cylindrical shell having an interior void, the outwardly extending pin 472 being seen to be a longer pin extending through holes either side of the cylindrical rail 472 and welded in place.

The pin 472 therefore serves to uniquely locate the shim clip 480 along the cylindrical rail 470, such that it does not slide either around the cylindrical rail or along it.

In the sliding mechanism 400 of Figure 12, the pin 472 also has additional functions. The shim clip 480 serves to provide the correct outer diameter for the cylindrical rail for contacting the bearing channel 430 of the seat bottom, and the bearing channel 430 and shim clip 480 may formed of materials selected for their low coefficient of friction, or for whichever coefficient of friction is desired. Also extending outward from the lower surface 410 of the seat bottom is a first stop 440 in the form of a cylinder extending downward from the lower surface 410 of the seat bottom. The first stop 440 is located to contact with the pin 472 of the cylindrical rail 470 to set a bound on the movement of the seat bottom relative to the chair frame.

Suitable materials out of which the shim clip 480 and bearing channel 430 may be constructed include POM (polyoxymethyline, also known as acetal), PA6 (also known as Nylon 6) and HDPE.

Shown more clearly in Figure 14, which is a cutaway view through the seat bottom normal to the direction of slidable movement, the seat bottom also comprises a second stop 450 in the form of two adjacent projections defining a channel between the projections, the channel extending parallel to the direction of slidable movement of the seat bottom relative to the chair frame. One or both of the pin-facing surfaces of the two projections either side of the channel are located to contact the pin 472 of the cylindrical rail 470 to set a second bound on the movement of the seat bottom relative to the chair frame. Therefore the seat bottom may be moved from one extreme, in which the first stop 440 contacts the pin 472, and a second extreme, in which the second stop 450 contacts the pin 472. Also extending from the lower surface 410 of the seat bottom is a lug 460, the lug 460 being located on the other side of the channel between the projections of the second stop 450.

The sliding mechanism 400 also includes a spring 490 extending between the pin 472 of the cylindrical rail 470 and the lug 460 of the seat bottom. The spring provides a restoring force to bias the seat bottom relative to the chair frame at or towards an equilibrium position. This may be at one extremity of the permitted movement of the seat bottom relative to the chair frame. The spring 490 has at one end a loop, through which the lug 460 extends, thereby attaching the spring 490 to the seat bottom. The spring 490 has at its other end a tube 492 for mounting on the outside of the pin 472 of the cylindrical rail, the spring 490 extending from an intermediate along the outer surface of the tube 492. The tube 492 is made of an elastomeric material such as natural rubber to provide a bumper against the first and second stops 440, 450, reducing any jarring or jerking forces as the sliding mechanism 400 reaches either extremity of its permitted movement range.

Figure 15 illustrates the assembled sliding mechanism at either extremity of its permitted movement range. The upper image shows the tube 492 about the pin 472 in contact with the first stop 440 of the seat bottom, with the spring 490 extending through the channel between the projections of the second stop 450 to attach via loop 494 to the lug 460. The spring is shown to be tensioned, and a restoring force is therefore provided to bias the seat bottom away from this extremity of its movement range. The lower image shows the seat bottom displaced via the sliding mechanism relative to the cylindrical rail 470 of the chair frame. The pin 472 ensures that the shim 480 does not slide but the bearing channel 430 on the lower surface 410 of the seat bottom, attached via mount 420, moves with the seat bottom. The tube 492 about the pin 472 is in contact with the projections of the second stop 450, the spring 490 being less tensioned as it extends through the channel between the projections of the second stop 450. A chair embodying an aspect of the invention may comprise more than one sliding mechanism.

Figure 16 is an underside view of an embodiment using two sliding mechanisms 400, the cylindrical rails 470 being located parallel to each other with pins 472 of the cylindrical rails 470 oriented inwards towards each other. The lower surface 410 of the seat bottom has attached to it the shown features of the lugs 460, the second stops 450, and the first stops 440, thus all of these shown features would slidably move with the seat bottom relative to the cylindrical rails 470, until the first or second stops 440, 450 contact the tubes 492 surrounding the pins 472.

Instead of springs 490, seat bottom may be biased relative to the frame by any other biasing means, such as an elastomeric band extending between the lugs 460 and the tubes 472.

Figure 17 shows an alternative embodiment in which , the lugs 460 are be replaced by a single central lug, the springs or elastomeric bands extending to the single central lug; in such configurations the elastomeric bands may be a single elastomeric band from one tube 472 to the other tube 472 via the single central lug. The elastomeric bands may be made from natural rubber. In embodiments using one or more elastomeric bands, the one or more elastomeric bands may be formed as a single component with the tubes 492 that provide a bumper against the first and second stops 440, 450. Chairs embodying aspects of the invention may include both springs and elastomeric bands, each via either a single central lug and/or the pair of lugs 460 as described herein.

The chair may comprise a cover suspended below the sliding mechanism(s) 400 to prevent dust settling in the sliding mechanism and or prevent anything interfering with or getting trapped in the mechanism or between moving parts. The cover may be attached to the lugs 460, first and second stops 440, 450. Alternatively dedicated elements may extend from the lower surface of seat bottom to retain the cover.

While the sliding mechanism 400 is shown with the bearing channel 430 attached to the lower surface 410 of the seat bottom via a mount 420, the bearing channel 430 may also be attached directly to the seat bottom.

Figure 18 shows an alternative embodiment of a bearing channel assembly 500 comprising a bearing channel 530 and retaining capsule 520 embodying an aspect of the invention. The alternative embodiment may be used with any of the above-described embodiments in place of or in addition to a bearing channel assembly described above.

The retaining capsule 520 is formed from the underside of the seat bottom 522 and comprises a pair of aligned opposing side walls 524 extending outward from the underside of the seat bottom 522, between which the bearing channel 530 is retained. The seat bottom 522 also comprises a pair of holes 526 at between the each pair of respective ends of the side walls 524. The bearing channel 530 is located between the pair of holes 526 and the pair of side walls 524 and includes at each of four corners a lever arm 560, each lever arm 560 being terminated with a bumper 570 for engaging with one of the side walls 524 of the capsule 520.

Figure 19 shows an isometric view of the capsule 520. The retaining capsule 520 is formed from the underside of the seat bottom 522 and comprises a pair of aligned opposing side walls 524 extending outward from the underside of the seat bottom 522, between which the bearing channel 530 is retained.

Figures 20A and 20B show isometric and plan views of the bearing channel 530. The bearing channel 530 has a concave cross sectional profile for receiving the shim clip 480 of a cylindrical rail 470 and allowing slidable motion relative to the shim clip 480 and cylindrical rail. The lever arms 560 are formed from a pair slots extending into the bearing clip from each ends of the bearing channel 530 aligned with the direction of slidable motion of the bearing channel 530. The pair of slots define a central portion, separated by the slots from the two lever arms 560. Extending outward from each central portion at either end of the bearing channel 530 is clip 580 for engaging with the holes 526 of the capsule 520 and retaining the bearing channel 530 axially along the capsule 520 as well as also preventing the bearing channel from being moveable outward of the capsule over the side walls 524.

The lever arms 560 and bumpers 570 allow the bearing channel to move laterally within the capsule 520 relative to the direction of slidable motion. This may accommodate any misalignment or manufacturing tolerance of the cylindrical rails 470 in the chair frame. While this could be achieved by making the width of the bearing channel 530 smaller than the distance between the side walls 524 of the capsule 520, the inclusion of the lever arms 560 and bumpers 570 have the effect that the bearing channel 530 continuously contacts the side walls 524 and so does not produce a rattle.

In chairs embodying aspects of the invention, the cylindrical rails may be oriented horizontal relative to a flat ground when in use. In other chairs embodying aspects of the invention, the cylindrical rails may be tilted to bias the seat bottom towards one extremity of its permitted slidable range, the tilted cylindrical rails thus comprising a biasing means.

Chairs embodying aspects of the invention may include any of the features described herein and any combination thereof. For example, a chair may comprise any of the pivot joints 300 described herein and the cushion assembly 100 described herein but omit the sliding mechanism 400 described herein; such a chair may omit sliding mechanisms altogether, with the seat back reclining but the seat bottom not sliding. Alternatively, a chair may comprise the sliding mechanism 400 and cushion assembly 100 but not comprise the pivot joint 300. For example, a different pivot join may be employed. Alternatively, the chair may comprise the sliding mechanism 400 and a pivot joint as described herein but omit the cushion assembly. While examples have been described with the seat back and seat bottom formed a one-piece shell, they may be formed as separate components and optionally linked by some flexible material or alternatively allowed to move independently of each other.

Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the technology of the disclosure as defined by the appended claims. For example, relational terms, such as “above” and “below”, “upper” and “lower” are used with respect to a chair and chair components. Of course, if the chair or chair components are inverted, above becomes below, and vice versa. Additionally, if oriented sideways, above and below may refer to sides of a chair or chair component.

While the present disclosure may refer to ‘joints’ and ‘mechanisms’ such as a pivot joint and sliding mechanism, it will be appreciated that these are of course types of bearings. Thus references to a sliding mechanism may be understood to refer to a linear-motion bearing assembly. References to a pivot joint may equally be understood to refer to a hinge bearing or joint.

Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Claims

1. A chair comprising: a frame including an elongate rail member and a first bearing element coupled to the elongate rail member, the elongate rail member including a transverse projection extending outward from the elongate rail member in a direction transverse to the direction in which the elongate rail member extends, the first bearing element covering a portion of the least one elongate rail member and having a hole into which the transverse projection of the elongate rail member extends; a seat bottom slidable relative to the elongate rail member of the frame on the first bearing element; and a seat back pivotably mounted to the frame by a pivot joint to permit pivotable movement of the seat back relative to the frame, the pivot joint comprising: a pin; a projection on a first body, the projection having a hole extending therethrough for receiving the pin; an insert having a hole extending therethrough for receiving the pin; and a recess on a second body, the recess being configured to receive the insert and permit pivotable movement of the projection about the pin with the insert, pin and projection located within the recess.

2. The chair of claim 1, wherein the hole through the insert includes a narrowing defining a first location on one side of the narrowing and a second location on the other side of the narrowing, the pin being positionable within the hole in either location, the narrowing of the hole resisting the change in position of the pin.

3. The chair of claim 2, wherein the pin includes a circumferential groove and the insert includes a protuberance extending outward from the inner surface of the hole at the first location to extend into the circumferential groove of the pin when the pin is positioned in the first location of the hole.

4. The chair of claim 3, wherein the pin includes a circumferential ridge at one end that is larger than the insert-hole first and second locations so that the pin is insertable into the hole of the insert with the non-ridged end only.

5. The chair of claim 3 or claim 4, wherein the insert is insertable into the recess with the pin and projection when the pin is positioned in the first location of the hole of the insert and, following the inserting of the insert, application of force between insert and the second body causes movement of the pin from the first location to the second location of the hole of the insert.

6. The chair of claim 5, wherein retention members located on the insert engage with corresponding portions of the recess to retain the insert in the recess when the insert is inserted into the recess and the pin is positioned in the second location of the hole of the insert.

7. The chair of any of claims 1 to 6, wherein the insert includes an arm, the hole extending through the arm.

8. The chair of claim 7, wherein the insert includes two arms each having holes extending therethrough for receiving the pin, the two holes each having axially aligned first and second locations, the two arms being spaced from each other to admit the projection of the first body between the arms.

9. The chair of claim 8, wherein the pin comprises a plurality of axially distinct portions of different widths, the widths of the holes of the first and second arms being different to provide that the pin is insertable into the insert from only one side of the insert.

10. The chair of any of claims 1 to 9, wherein the recess is located on the frame and the projection of the pivot joint is located on the seat back.

11. The chair of any of claims 1 to 10, wherein the frame comprises an elongate back support member for supporting the seat back, the elongate member extending from a left side of the chair to a right side of the chair the perspective of a user occupying the chair, the seat back being pivotably mounted on the elongate back support member.

12. The chair of any of claims 1 to 11 comprising a plurality of pivot joints between the seat back and the frame, preferably two pivot joints.

13. The chair of claim any of claims 1 to 12 wherein the seat bottom comprises a second bearing element for slidable engagement with the first bearing element.

14. The chair of claim 13 wherein the first bearing element has a convex cross section normal to the direction of slidable movement and the second bearing element has a concave cross section normal to the direction of slidable movement.

15. The chair of claim 14 wherein the elongate rail member has a circular cross section and the first bearing element has a ‘C’-shaped cross section extending around a portion of the circumference of the elongate rail member.

16. The chair of claim 15 wherein the first bearing element extends at least 180e around the circumference of the elongate rail member.

17. The chair of any of claims 1 to 16 wherein the first bearing element is configured to snap-fit to the elongate rail member.

18. The chair of any of claims 1 to 17 comprising two elongate rail members each having coupled thereto a respective first bearing element.

19. The chair of any of claims 1 to 18 wherein the hole in the first bearing element is a through hole and the transverse projection extends through the through hole in the first bearing element.

20. The chair of any of claims 1 to 19 wherein the seat bottom comprises at least one stop projecting outward from the seat bottom to engage with the transverse projection of the elongate rail member at a particular displacement of the seat bottom relative to the elongate rail member to limit the slidable range of the seat bottom relative to the elongate rail member.

21. The chair of claim 20 wherein the seat bottom comprises two stops projecting outward from the seat bottom, each engaging with the transverse projection of the elongate rail member at a different displacement of the seat bottom relative to the elongate rail member and defining two bounds between which the seat bottom is slidable relative to the elongate rail member.

22. The chair of claim 20 or claim 21 wherein the chair is configured to provide a biasing force to the seat bottom when displaced from an equilibrium position.

23. The chair of claim 22 wherein the chair is configured to bias the seat bottom to one end of the slidable range.

24. The chair of claim 22 or claim 23 comprising a spring coupled to the transverse element and to the seat bottom, the spring providing a biasing force to the seat bottom.

25. The chair of any of claims 22 to 24 comprising at least one elastomeric band, the at least one elastomeric band providing a biasing force to the seat bottom.

26. The chair of any of claims 22 to 25 wherein, when the chair in place on a horizontal floor, the elongate rail is inclined to the horizontal, such that gravity provides a biasing force to the seat bottom.

27. The chair of any preceding claim wherein the seat back and seat bottom comprise portions of a one-piece shell.

28. The chair of claim any preceding claim wherein the seat bottom and seat back are configured to move synchronously relative to the frame.

29. A chair comprising: a frame including an elongate rail member and a first bearing element coupled to the elongate rail member, the elongate rail member including a transverse projection extending outward from the elongate rail member in a direction transverse to the direction in which the elongate rail member extends, the first bearing element covering a portion of the least one elongate rail member and having a hole into which the transverse projection of the elongate rail member extends; a seat bottom slidable relative to the elongate rail member of the frame on the first bearing element; and a seat back pivotably mounted to the frame by a pivot joint to permit pivotable movement of the seat back relative to the frame.

30. A chair comprising a frame, a seat bottom slidable relative to the frame; a seat back pivotably mounted to the frame by a pivot joint to permit pivotable movement of the seat back relative to the frame, the pivot joint comprising: a pin; a projection on a first body, the projection having a hole extending therethrough for receiving the pin; an insert having a hole extending therethrough for receiving the pin; and a recess on a second body, the recess being configured to receive the insert and permit pivotable movement of the projection about the pin with the insert, pin and projection located within the recess.

31. A pivot joint for pivotable movement of a first body relative to a second body, the pivot joint comprising: a pin; a projection on the first body, the projection having a hole extending therethrough for receiving the pin; an insert having a hole extending therethrough for receiving the pin; and a recess on a second body, the recess being configured to receive the insert and permit pivotable movement of the projection about the pin with the insert, pin and projection located within the recess.

32. A chair substantially as described herein with reference to the accompanying drawings.

33. A pivot joint substantially as described herein with reference to the accompanying drawings.