Torsion Bar Or Torsion Spring Patents (Class 297/301.3)
  • Patent number: 9102247
    Abstract: A vehicle seat bar assembly having a seat with first and second engagement members. A rear seat bracket extends between the first and second engagement members of a seat. A torsion bar extends between the first and second engagement members and is operably engaged therewith. The torsion bar includes an intermediate bracket engagement portion and a first and second linear portion that extends between the first engagement member and the intermediate bracket engagement portion and the second engagement member and the intermediate bracket engagement portion. The torsion bar also includes a first and second distal end configured to engage the first and second engagement members, respectively, which induces a torsional resistance in the torsion bar when the seatback is at a fully reclined position and when the seatback is at a fully folded position.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: August 11, 2015
    Assignee: Ford Global Technologies, LLC
    Inventors: Richard Li, Paul Gerard Ferraiuolo, Roy Chapman, Ammeswara Rao Sajja, Glenn Scott, Brandon Nichols
  • Patent number: 8979199
    Abstract: A chair with a pre-pressing structure includes a chair body and a pre-pressing structure enabling the chair body to be provided with elastic restoring force. The chair is characterized in that the pre-pressing structure includes a pre-pressing member's fixed seat, a pre-pressing member, a pivoting seat, a pre-pressing positioning member and a pre-pressing angle.
    Type: Grant
    Filed: July 11, 2012
    Date of Patent: March 17, 2015
    Inventor: Wen-Shan Ko
  • Publication number: 20140339870
    Abstract: Seat furniture is provided that includes a seat and a backrest support which are mounted on a support member, the backrest support being pivotal about a horizontal pivot axis, and an energy accumulator which is tensioned when the seat is subjected to a load and acts on the backrest support, the energy accumulator engaging the backrest support at an effective distance from the pivot axis, characterized in that the energy accumulator is connected on one side to the support member and on another side via a transverse connector to the backrest support.
    Type: Application
    Filed: August 1, 2014
    Publication date: November 20, 2014
    Inventor: Johannes Uhlenbrock
  • Patent number: 8696064
    Abstract: A backrest inclination structure for lumbar support enables a backrest to enter a free state when a user sitting at any position of a chair lifts a lever of a spring continuous control unit, such that the backrest fits the user's moving back when the backrest is configured for movable inclination. Hence, the backrest can move together with the user's back ergonomically to provide lumbar support. Accordingly, the user can sit comfortably on the chair and be free from lumbago and kyphosis which are common among sedentary individuals.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: April 15, 2014
    Assignee: Oasyschair Co., Ltd.
    Inventor: Tung-Chun Pan
  • Patent number: 8668267
    Abstract: A chair comprising a basic structure, a seat, a backrest, and at least one joint made of plastic material, which connects the backrest to the basic structure, wherein the joint has a first connection portion fixed to or integral with respect to the backrest, and a second connection portion connected to the basic structure, wherein said second connection portion comprises a first and a second arm, which are elongated in a longitudinal direction and are set at a distance from one another in a vertical direction, wherein the first arm has a front portion fixed to the basic structure and is deformable between a resting position corresponding to the resting position of the backrest and a deformed position corresponding to the position where the backrest is tilted backwards, wherein the second arm has a front portion, which is mobile in a longitudinal direction with respect to the basic structure between a first position corresponding to the resting position of the first arm, and a second position corresponding to
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: March 11, 2014
    Assignee: Pro-Cord S.p.A.
    Inventor: Alessandro Piretti
  • Patent number: 8506013
    Abstract: In a vehicle seat that includes a seat cushion, a seatback that is rotatably attached to the seat cushion, and a spring that urges the seatback to a raised upright position from a reclined position in which the seatback is tilted back behind the seat cushion, the spring is spiral shaped, with a center-side end portion that is arranged near the rotational center of the seatback hooked on a seatback-connected member and an outside end portion that is positioned on the outer peripheral side of the spring hooked on a seat cushion-connected member. A shield member that covers the spring is attached to the seat cushion.
    Type: Grant
    Filed: February 22, 2010
    Date of Patent: August 13, 2013
    Assignee: Toyota Boshoku Kabushiki Kaisha
    Inventors: Makoto Esaki, Akira Konagai
  • Patent number: 8485604
    Abstract: A seat assembly including a seat base, a back support, a support for the back support and/or for the seat base and at least one elastomer torsion-spring element. The back support and/or the seat base are/is pivotably hinged to the support in such a manner that a pivoting movement of the back support and/or of the seat base on a rotation axis can be carried out. During the respective pivoting movement of the back support and/or of the seat base with the elastomer torsion-spring element a restoring torque is generated that acts on the back support and/or on the seat base. The elastomer torsion-spring element includes an internal casing, an external casing encompassing the internal casing, and an elastomer body arranged in a space between the internal casing and the external casing. The elastomer body is rigidly connected to contact surfaces of the internal and external casings. The internal casing and/or the external casing are/is rotatably arranged on a rotation axis.
    Type: Grant
    Filed: January 14, 2011
    Date of Patent: July 16, 2013
    Assignee: Stoll Giroflex AG
    Inventors: Stephan Pfeifer, Wolfgang Emmenegger
  • Patent number: 8480171
    Abstract: A chair having a seat rotatably attached to a tilt spring portion of a tilt mechanism such that the tilt spring is activated by movement of the seat. A backrest and/or the seat can be rotatably connected to the tilt mechanism by parallel arm arrangements which permit the seat and backrest to tilt relative to each other. A tilt limiter can have a magnetic member which facilitates full movement of the tilt limiter between free and locked positions, and which creates an audible indication of full movement of the tilt limiter. The seat/backrest can be made from a flexible mesh material secured to a rigid overmolding which surrounds and is attached to an inner frame of the seat/backrest wherein an outer surface of the overmolding forms an outer surface of the seat/backrest frame and attachment of the overmolding causes the inner frame to stretch the mesh to a final condition.
    Type: Grant
    Filed: July 8, 2005
    Date of Patent: July 9, 2013
    Assignee: Knoll, Inc.
    Inventors: Donald T. Chadwick, Arkady Golynsky, Robert A. Melhuish, Hendrik R. van Hekken, Ron K. Watson
  • Patent number: 8424968
    Abstract: A tubular spring having a longitudinal slot that is attached between a movable member and a fixed attachment device. A recliner hinge assembly for a vehicle seat that includes an inboard recliner and an outboard recliner connected by a connecting rod. A split tube having a longitudinally extending slot is assembled over the connecting rod. The split tube biases the seat back toward a neutral position when the seat back is shifted to a position that is angularly offset from the neutral position.
    Type: Grant
    Filed: October 4, 2010
    Date of Patent: April 23, 2013
    Assignee: Lear Corporation
    Inventors: Mladen Humer, Karl Schafer
  • Patent number: 8348341
    Abstract: A chair assembly has a base frame, a pivot frame, a backrest frame, a seat frame and a backrest-adjusting device. The pivot frame is mounted pivotally on the base frame. The backrest frame is mounted securely on the pivot frame. The backrest-adjusting device is mounted between the base frame and the pivot frame and has a torsion spring biasing the pivot frame and the backrest frame to pivot forward. The backrest-adjusting device tightens or loosens the torsion spring to change the resilient force provided to the backrest frame against users' back. Therefore, the chair assembly adapts to differ users well.
    Type: Grant
    Filed: September 21, 2010
    Date of Patent: January 8, 2013
    Inventor: Yun-Chien Hsiao
  • Patent number: 8348346
    Abstract: A vehicle seat spring assembly having an engagement post connected to one of a seat and a seat back. A coil spring includes an internal end and an external end. The external end is operably connected with the engagement post. An arcuate engagement bracket is connected to the other of the seat and the seat back. The engagement bracket includes an elongate slot adapted to operably engage the internal end of the coil spring. The internal end moves between a compression position in contact with a first end of the elongate slot corresponding to a first predetermined position of the seat back relative to the seat. A tension position is in contact with a second end of the elongate slot corresponding to a second predetermined position of the seat back relative to the seat.
    Type: Grant
    Filed: April 22, 2010
    Date of Patent: January 8, 2013
    Assignee: Ford Global Technologies, LLC
    Inventor: Yuenian Richard Li
  • Patent number: 7819473
    Abstract: A chair is provided that is designed so that the angle of the seat surface portion and the angle of the back surface portion are independent of each other and change, and a user can always take the optimum seated posture. The chair includes a base portion, a first link fixed to a seat and rotatably connected to the base portion, and a second link fixed to a seat back rest and rotatably connected to the first link. The chair also includes a first torque-generating mechanism that generates torque in accordance with the angle of the first link relative to the base portion; and a second torque-generating mechanism that generates torque in accordance with the angle of the second link relative to the first link.
    Type: Grant
    Filed: August 4, 2009
    Date of Patent: October 26, 2010
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Zenroh Fukai
  • Patent number: 7722120
    Abstract: An automobile seat in which spaced apart side brackets of a seat back are individually faced to spaced apart side brackets of a seat cushion, a pivot shaft is penetrated through the brackets and bridged between the brackets, and reclining lock devices are assembled on the axis of the pivot shaft to the side brackets, whereby the seat back is held upright such that the angle of the seat back relative to the seat cushion is adjustable and that the seat back is reclinable forward and rearward, and in which the seat back is urged by return spring members to the upright direction. The spring members comprise first and second torsion bar springs that are arranged in proximity to the pivot shaft. The springs are engaged at both end portions thereof with corresponding side brackets in such a manner that the springs cross each other.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: May 25, 2010
    Assignee: TS Tech Co., Ltd.
    Inventors: Osamu Toyooka, Masanobu Kojima
  • Patent number: 7681952
    Abstract: A chair having a base adapted to support the chair on a support surface, and a seat and backrest mounted on the base that includes a flexible backrest and a relatively simple tilt mechanism for tilting the backrest relative to the seat. The tilt mechanism includes a pair of dual cantilevered U-shaped springs mounted on opposite sides of the base and in communication with the backrest. The backrest is mounted to the tilt mechanism such that a rearward thrust applied by the user deflects an outer end of each U-shaped spring downwardly to enable rearward tilting of the backrest relative to the seat. Upon removal of the rearward thrust, the backrest elastically returns to its initial position under the biasing force of the U-shaped springs.
    Type: Grant
    Filed: June 6, 2008
    Date of Patent: March 23, 2010
    Assignee: Pro-Cord S.p.A.
    Inventor: Giancarlo Piretti
  • Patent number: 7631936
    Abstract: The invention provides a reclining apparatus which can make a width of an apparatus small. The reclining apparatus of the present invention is provided with a first bracket (1) attached to a seat back (10), a second bracket (2) attached to a seat cushion (11), a first shaft (3) forming a rotation center of the first bracket (1), a spiral spring (5) spirally wound around the first shaft (3) and biasing a rotation in a forward direction of the first bracket (1), and a rotary damper (6) decelerating a rotating speed of the first bracket (1) against an biasing force of the spiral spring (5). The rotary damper (6) and the spiral spring (5) are arranged in parallel, and an arm (7) rotating a casing (6a) of the rotary damper (6) on the basis of a rotation of the first bracket (1) is provided between the rotary damper (6) and the second bracket (2).
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: December 15, 2009
    Assignee: NHK Spring Co., Ltd.
    Inventors: Takao Fukukawa, Masaaki Takii, Hiroshi Yokoyama, Nobuhito Kanae
  • Publication number: 20090302654
    Abstract: A chair having a base adapted to support the chair on a support surface, and a seat and backrest mounted on the base that includes a flexible backrest and a relatively simple tilt mechanism for tilting the backrest relative to the seat. The tilt mechanism includes a pair of dual cantilevered U-shaped springs mounted on opposite sides of the base and in communication with the backrest. The backrest is mounted to the tilt mechanism such that a rearward thrust applied by the user deflects an outer end of each U-shaped spring downwardly to enable rearward tilting of the backrest relative to the seat. Upon removal of the rearward thrust, the backrest elastically returns to its initial position under the biasing force of the U-shaped springs.
    Type: Application
    Filed: June 6, 2008
    Publication date: December 10, 2009
    Inventor: Giancarlo Piretti
  • Patent number: 7568763
    Abstract: A seating unit includes a base with a control housing, a back supported on the base for reclining movement, and a seat supported at least partially by a pivoting link on the base for synchronous movement with the back upon recline of the back. A back stop is operably mounted on a pair of parallel guide rods that extend transversely across the control housing for selective movement to a plurality of different positions where the back stop engages the link to limit movement of the seat and hence limit recline of the back to a plurality of selectable recline positions corresponding to the plurality of different positions.
    Type: Grant
    Filed: December 2, 2005
    Date of Patent: August 4, 2009
    Assignee: Steelcase Inc.
    Inventors: Adam C. Bedford, David A. Bodnar, Gary Lee Karsten, Robert J. Battey, Kurt R. Heidmann, Gordon J. Peterson
  • Publication number: 20090091170
    Abstract: A chair seat adapted to be mounted on or in a frame, and comprising a seat part (4) and a backrest part (5), which parts are functionally separate units, and which are joined by a spring means which allows the backrest part to move resiliently in relation to the seat part, and in which the spring means comprises one or more thin flexible strips of a spring material, preferably a carbon fibre web material, comprising a flat upper spring part (2a) which is fixed to the backrest part (5) of the chair seat and a flat lower spring part (2b) which is fixed to the seat part (4) of the chair seat, and in which the spring means (2) is formed with a curved spring part (8) between the two flat spring parts (2a, 2b) which is substantially free from the seat and the backrest, and which provides a spring action and a counter spring action of the backrest (5) in relation to the seat part (4).
    Type: Application
    Filed: April 24, 2006
    Publication date: April 9, 2009
    Inventors: Norbert Grentzelius, Ann Sandell, Lennart Noack, Stefan Hultgren
  • Publication number: 20090066134
    Abstract: A permanent-contact mechanism for an office chair or the like is formed as a comparatively flat permanent-contact mechanism with a seat frame, which can be positioned on a chair upright, with a backrest support, which is arranged on the seat frame such that it can be pivoted about a transverse axis, and with at least one spring-activated or inherently resilient lever element, which interacts with the backrest support such that the backrest support is always pivoted counter to a spring force. The position of the point of rotation of the lever element differs from the position of the transverse axis.
    Type: Application
    Filed: January 12, 2006
    Publication date: March 12, 2009
    Applicant: BOCK 1 GMBH & CO. KG
    Inventor: Hermann Bock
  • Publication number: 20080084101
    Abstract: A chair having a back portion that is slidably biased with respect to a seat portion. The back portion slides forward against the occupant's back as the occupant slides forward in the seat. The occupant may set an initial position of the back portion if she or she wishes to sit back in the chair. Optional folding armrests slide together with the back portion. The back portion may also tilt with respect to the seat portion so as to better conform to the occupant's back.
    Type: Application
    Filed: October 4, 2006
    Publication date: April 10, 2008
    Inventors: Mark Powicki, Stephen James Messineo
  • Patent number: 7325873
    Abstract: A seating unit comprising a base configured to be positioned on a floor, a torsional energy unit connected to the base, a back connected to the torsional energy unit and a seat rotatably connected to the torsional energy unit. The torsional energy unit biases the back to a forward position. The torsional energy unit further limits angular rotation of the seat between a substantially horizontal seating position and a substantially vertical seating position.
    Type: Grant
    Filed: June 13, 2005
    Date of Patent: February 5, 2008
    Assignee: Steelcase Inc.
    Inventors: Robert Lawrence Stewart, David J. Ritch, Mark B. Saffell, Ari T. Adler, Anthony Peter Patron, Matthew David Inouye, Alan Chung Regala, Jonathan I. Kaplan, James Yurchenco
  • Patent number: 7243993
    Abstract: A chair has a backrest and a pair of armrests. A pair of support struts for supporting the backrest is connected to a shaft of a base under a seat. The armrest is supported by an arm post. An operating lever is mounted on the upper front end of the arm post. When the backrest is tilted, it is held at a desired angle by pressing up the operating lever.
    Type: Grant
    Filed: July 10, 2006
    Date of Patent: July 17, 2007
    Assignee: Okamura Corporation
    Inventors: Ryo Igarashi, Naoki Numa, Ken Nakayama, Hiroshi Masunaga
  • Patent number: 7237841
    Abstract: A back construction includes a back shell mounted on a back frame at top and bottom connections, and a flexible lumbar section biased forwardly by a biasing device. The bottom connection is located rearward of the back shell to allow unencumbered sliding entry into the seating unit from a lateral side position, but the bottom connection defines a virtual pivot forward of its physical location to provide the desired path of flexure when the lumbar section is flexed. In one form, the bottom connection is a pair of non-parallel links of dissimilar length. In another form, the bottom connection is a follower with two bearings following a guide slot. In some variations, the force of the biasing device is variable. Seating units incorporating the back construction include a vehicle seat, a foldable portable stadium seat, and a wheelchair seat.
    Type: Grant
    Filed: February 1, 2005
    Date of Patent: July 3, 2007
    Assignee: Steelcase Development Corporation
    Inventors: Christopher J. Norman, Kurt R. Heidmann
  • Patent number: 7097249
    Abstract: A chair has a backrest and a pair of armrests. A pair of support struts for supporting the backrest is connected to a shaft of a base under a seat. The armrest is supported by an arm post. An operating lever is mounted on the upper front end of the arm post. When the backrest is tilted, it is held at a desired angle by pressing up the operating lever.
    Type: Grant
    Filed: July 17, 2003
    Date of Patent: August 29, 2006
    Assignee: Okamura Corporation
    Inventors: Ryo Igarashi, Naoki Numa, Ken Nakayama, Hiroshi Masunaga
  • Patent number: 6779847
    Abstract: A chair control mechanism for positioning between the seat and seat support of a chair. The chair control mechanism includes a base section for mounting to a seat support such as an adjustable height cylinder, and a seat mounting section pivotally interconnected with the base section. A seat is mounted to the seat mounting section, and is pivotal about a seat pivot axis. An adjustable position back mounting arrangement is pivotally interconnected with the seat mounting section, and the chair back is engageable with the back mounting section. A variable stop arrangement is interposed between the base section and the seat mounting section, for varying the range of pivoting movement of the seat relative to the seat support. The back can be selectively locked in one of a number of predetermined positions relative to the seat by operation of a variable position back locking arrangement.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: August 24, 2004
    Assignee: L & P Property Management Company
    Inventor: Michael N. Klein
  • Patent number: 6761406
    Abstract: In a chair 1 having an upholstery member 7 fitted on a backrest portion or seat plate 4 serving as a portion adapted to contact a human body, upright portions 41 and elastic pieces 8 allowing their deflection in the direction in which the load of a human body contacting the chair works are provided and the upholstery member 7 is placed over the upright portions 41 and elastic pieces 8 so that the contacting portion of the seat portion or backrest portion is imparted with elasticity to ensure a better sitting comfort even if the upholstery member 7 lacks elasticity.
    Type: Grant
    Filed: August 14, 2002
    Date of Patent: July 13, 2004
    Assignee: Kokuyo Co., Ltd.
    Inventors: Yojiro Kinoshita, Nobuyuki Ueda
  • Patent number: 6739664
    Abstract: A chair 1 allowing a person sitting thereon to move a part of the person's body above the waist which corresponds to the backrest of the chair is provided having a backrest portion located behind a seat portion, the backrest portion being divided into backrest upper frames 55 and backrest lower frames 50, wherein a first state which allows the whole backrest frame 5 to incline rearwardly and a second state which allows the backrest upper frames 55 to incline rearwardly relative to the backrest lower frames 50 are assumed, the first state and the second state being switchable to each other.
    Type: Grant
    Filed: May 23, 2002
    Date of Patent: May 25, 2004
    Assignees: Kokuyo Co., Ltd., Takano Co., Ltd.
    Inventors: Yojiro Kinoshita, Nobuyuki Ueda, Toshiyuki Horiki, Kazuyuki Itoh
  • Patent number: 6672669
    Abstract: A chair having a swingable chair back with a top pivot includes a frame having laterally spaced first and second uprights. A back having upper and lower ends is attached to the frame. Also attached to the frame adjacent the lower end of the back is a seat. A pivot assembly couples the first and second uprights to the back and permits pivoting of the back about a substantially horizontal pivot axis. The pivot axis projects laterally of the back and is positioned in the vicinity of the upper end of the back. A biasing device cooperates with the back and normally urges the lower portion of the back forwardly away from a rearward position.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: January 6, 2004
    Assignee: First Source Furniture Group LLC
    Inventors: Zooey C. Chu, David J. Lambert
  • Patent number: 6659554
    Abstract: An adjustment device of a chair backrest includes a fixed member a movable member and a fixing spanner. The fixed member is fixed to a bottom of a seat of a chair. The movable member is pivoted to the fixed member, and a support rod of the backrest is connected to a rear end of the movable member. The fixing spanner is connected to an outer end of a bolt passing through both a lateral curved slot of the fixed member and a round hole of the movable member from a connecting end portion thereof so as to be turnable between an unlocking position for allowing adjustment of the backrest and a locking position for fixing the movable member after the adjustment. The fixed member further has a curved bump enclosing the curved slot. The bump has a tapering lateral side with an upper portion bigger than a lower portion thereof, whereby the backrest can be further secured in position after the adjustment.
    Type: Grant
    Filed: February 1, 2002
    Date of Patent: December 9, 2003
    Inventor: Wen-Fa Su
  • Publication number: 20030197407
    Abstract: Healthy task seating is achieved by integrating three dynamics into a unique, dynamically balanced chair design that provides: (a) adaptable design features to accommodate a wide range of body dimensions, (b) a series of independent and adjustable support means to accommodate a wide range of tasks, and (c) means for promoting active seating.
    Type: Application
    Filed: March 28, 2003
    Publication date: October 23, 2003
    Inventor: Gary L. Sanchez
  • Patent number: 6631954
    Abstract: A vehicle seat has a back mounted to pivot on a seat proper by a locking mechanism, and urged forwards by a torsion bar formed by a metal wire which has two ends fixed respectively to the back and to the seat proper. The metal wire constituting the torsion bar forms at least one spiral comprising a plurality of adjacent turns.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: October 14, 2003
    Assignee: Faurecia Siege d' Automobile S.A.
    Inventors: David Amorin, Yves Geoffroy
  • Patent number: 6612652
    Abstract: A theater seat assembly includes a pair of opposed stanchions for attachment to a support surface, a generally horizontal seat portion disposed between and operatively connected to the stanchions, and a generally upright back portion disposed between and operatively connected to the stanchions. The theater seat assembly may include a lounge mechanism operatively connected to the back portion and the stanchions to allow the back portion to lounge rearward relative to the stanchion. The theater seat assembly may also include a cushion suspension system operatively connected to the seat portion and the stanchions to allow the seat portion to deflect downwardly relative to the stanchions. The theater seat assembly may further include each one of the seat portion and the back portion having a frame, a cushion disposed adjacent the frame and a trim cover covering the cushion and attached to the frame.
    Type: Grant
    Filed: August 28, 2000
    Date of Patent: September 2, 2003
    Assignee: Greystone International, Inc.
    Inventors: Alex Tenenboym, Daniel M. Duhaime, Mark Matthews, Norman L. Freeman, Teh-Feng Fang
  • Publication number: 20030146652
    Abstract: An adjustment device of a chair backrest includes a fixed member a movable member and a fixing spanner. The fixed member is fixed to a bottom of a seat of a chair. The movable member is pivoted to the fixed member, and a support rod of the backrest is connected to a rear end of the movable member. The fixing spanner is connected to an outer end of a bolt passing through both a lateral curved slot of the fixed member and a round hole of the movable member from a connecting end portion thereof so as to be turnable between an unlocking position for allowing adjustment of the backrest and a locking position for fixing the movable member after the adjustment. The fixed member further has a curved bump enclosing the curved slot.
    Type: Application
    Filed: February 1, 2002
    Publication date: August 7, 2003
    Inventor: Wen-Fa Su
  • Patent number: 6598936
    Abstract: A chair control mechanism for positioning between the seat and seat support of a chair. The chair control mechanism includes a base section for mounting to a seat support such as an adjustable height cylinder, and a seat mounting section pivotably interconnected with the base section. A seat is mounted to the seat mounting section, and is pivotable about a seat pivot axis. An adjustable position back mounting arrangement is pivotably interconnected with the seat mounting section, and the chair back is engageable with the back mounting section. A variable stop arrangement is interposed between the base section and the seat mounting section, for varying the range of pivoting movement of the seat relative to the seat support. The back can be selectively locked in one of a number of predetermined positions relative to the seat by operation of a variable position back locking arrangement.
    Type: Grant
    Filed: April 11, 2001
    Date of Patent: July 29, 2003
    Inventor: Michael N. Klein
  • Patent number: 6585320
    Abstract: An improved tilt rate control mechanism for a tilt back chair has an adjustable torsion spring, a tilt rate adjustment actuator and an actuator movement mechanism. The torsion spring has an adjustment lever for adjusting the tension on the torsion spring. The tilt rate adjustment actuator is disposed in contact with the adjustment lever such that the movement of the adjustment actuator causes movement of the adjustment lever. The adjustment actuator is moveable between (i) a first actuator position wherein the actuator is proximal to the torsion spring and the adjustment lever is in a minimum tension position, and (ii) a second actuator position wherein the actuator is distal from the torsion spring and the adjustment lever is in a maximum tension position.
    Type: Grant
    Filed: June 15, 2001
    Date of Patent: July 1, 2003
    Assignee: Virco Mgmt. Corporation
    Inventors: Richard M. Holbrook, Darren M. Mark
  • Patent number: 6536841
    Abstract: A synchrotilt chair includes a base, a back, a seat, and a link(s) pivoted to a rear of the base and to a bottom of the back to form a four-bar linkage arrangement. A spring arrangement includes a resilient member at one of the joints of each link to bias the link and in turn the back and seat toward an upright position, with the back and seat pivoting with a synchronous motion upon recline of the back. In one form, the chairs are nestable and stackable for dense storage. In another form, the chairs are desk-type pedestal chairs. Several of the structural support members of the chair are gas-assisted injection molding to form a hollow tubular shape that is lightweight, strong, and dimensionally-accurate. Armrests are pivoted to the back and have a shape configured to allow nested stacking while also providing excellent comfort, durability, and style. Also, the armrests are movable to remote storage positions to provide unobstructed side access to the seat of the chair.
    Type: Grant
    Filed: May 25, 2000
    Date of Patent: March 25, 2003
    Assignee: Steelcase Development Corporation
    Inventors: Peter J. Pearce, Kurt R. Heidmann, Robert J. Battey, Dale M. Groendal, Bruce M. Smith
  • Patent number: 6533352
    Abstract: A chair having a seat and a back rest. The back rest is attached to the seat via a back rest support element. The flat spring can be made from a non-metallic material, such as from fiberglass. The back rest support element comprises a flat spring disposed under pretension. In one embodiment, the seat is disposed upon a seat support structure having four legs. Preferably, the legs are splayed outside the perimeter of the seat, so that the chair is stackable with chairs of like design. The seat and the back rest can be made from a lightweight plastic material, and that the support structure can be made from tubular steel.
    Type: Grant
    Filed: July 7, 2000
    Date of Patent: March 18, 2003
    Assignee: Virco Mgmt. Corporation
    Inventors: Peter Glass, Jamie Toland
  • Patent number: 6523896
    Abstract: A chair is provided comprising a seating platform having a front edge and a back edge, a seat carrier that carries the seating platform and is connected to one of a central chair column and a plurality of chair legs, a rest carrier that proceeds toward the back under the seating platform and upward behind the seating platform, and a backrest carried on the rest carrier. The seating platform, close to its front edge, is hinged to the seat carrier pivotable around a transversely proceeding, first swivelling axis and, offset therefrom toward the back edge, is hinged to the rest carrier pivotable around a parallel, second swivelling axis. The rest carrier is hinged to the seat carrier pivotable around a third swivelling axis that is located between the first and second swivelling axis and parallel thereto. A spring is provided under the seating platform and supported thereat which exerts a pre-stress force acting upwardly on the seating platform and toward the front on the back rest.
    Type: Grant
    Filed: July 5, 2000
    Date of Patent: February 25, 2003
    Inventor: Johannes Uhlenbrock
  • Patent number: 6494537
    Abstract: Chair mechanism especially for office chairs and larger arm chairs, characterized in one end of a torsion spring (1); being fixedly connected with one end of an inner pipe (3) being turnably supported in a pipe (4), the other end being supported turnably in an outer pipe (2) which again is secured to the other end of the spring (1), the outer pipe (2) and the pipe (4) being fixedly connected with each other through an angle profile (12) securing a fixed connection between the outer pipe (2), the pipe (4), the angle profile (12), the seat (13) of the chair and the two back supports (10, 11) of the chair which are secured at a distance from each other to respectively the outer pipe (2) or the pipe (4), a pressure arm (8) being connected with a centre portion of the inner pipe (3) between the pipe (4) and the outer pipe (2) and the pressure arm (8) abutting with a prestress against a bow mechanism (5) connected to the fundament of the chair and adjustable by means of a screw (9).
    Type: Grant
    Filed: December 5, 2000
    Date of Patent: December 17, 2002
    Assignee: Ring Holding AS
    Inventor: Tore Lie
  • Publication number: 20020158496
    Abstract: A chair having a swingable chair back with a top pivot includes a frame having laterally spaced first and second uprights. A back having upper and lower ends is attached to the frame. Also attached to the frame adjacent the lower end of the back is a seat. A pivot assembly couples the first and second uprights to the back and permits pivoting of the back about a substantially horizontal pivot axis. The pivot axis projects laterally of the back and is positioned in the vicinity of the upper end of the back. A biasing device cooperates with the back and normally urges the lower portion of the back forwardly away from a rearward position.
    Type: Application
    Filed: November 30, 2001
    Publication date: October 31, 2002
    Inventors: Zooey C. Chu, David J. Lambert
  • Patent number: 6406096
    Abstract: A chair including a seat assembly having an improved seat spring system to provide a flexible spring backrest frame. A pair of ends of spaced apart backrest frame members are arranged in registry with respective ends of seat support frame members, with each end positioned in spaced apart alignment across a gap from the respective end of each frame member. An elongated shaped flexible spring element spans each gap, with each spring element having opposed ends being extended a distance along each frame member from the gap. Each opposed end is restrained by a first and a second elongated U-shaped holder receptor paired and separately attachable to each opposed end of the spring element. Each holder receptor includes an opening end being faced towards and in alignment with the second holder opening end. The spring element is positioned between each opening end in side-by-side orientation beside the frame members, providing controlled angular range of motion of the backrest frame when moved by a chair occupant.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: June 18, 2002
    Assignee: Shelby Williams Industries, Inc.
    Inventor: Peter Barile, Sr.
  • Patent number: 6220664
    Abstract: A base structure for a chair seat includes a base mounted to an underside of the chair seat. Two lateral walls of the base include aligned vertical slots. A first pin is slidably extended through the aligned vertical slots. One of the lateral walls includes a retaining slot with a number of vertical retaining positions. The other of the lateral walls includes a guiding slot in alignment with the retaining slot A swivel seat includes a first end pivotally mounted between the lateral walls of the base by a second pin. The swivel seat is connected to an end of a backrest to pivot therewith. An adjusting rod has a first operative end and a second end extended through a second end of the swivel seat and the lateral walls of the base. The second end of the adjusting rod is releasably engaged with one of the vertical retaining positions, thereby allowing adjustment of an inclination angle of the backrest relative to the seat.
    Type: Grant
    Filed: August 26, 1999
    Date of Patent: April 24, 2001
    Inventor: Ming-Hao Lee