Patent Publication Number: US-7721399-B2

Title: Method for replacing a telescoping cylinder in a reconfigurable chair

Description:
This application is a division of application Ser. No. 11,257,076 filed on Oct. 25, 2005, which is still pending. 

   FIELD OF THE INVENTION 
   This invention relates to a chair, such as an office chair, which is reconfigurable by actuating a telescoping cylinder. 
   BACKGROUND OF THE INVENTION 
   Many chairs that are used in commercial environments, such as office chairs, have a height adjustment mechanism for permitting the height of the chair to be raised or lowered to accommodate a user. Typically, the height adjustment mechanism includes a cylinder, such as a pneumatic cylinder (also known in the industry as a gas damper). By opening a valve in the cylinder, the height of the seat, with respect to the floor engaging portion of the chair, may be adjusted. 
   Many such chairs also have a seat tilt and/or a back tilt mechanism. Accordingly, the inclination of the seat and/or the inclination of the back rest may be adjusted. In some cases, synchronous tilt mechanisms are used, whereby the adjustment of the angle of the backrest occurs concurrently with the adjustment of the inclination of the seat. These adjustment mechanisms may also utilize a telescoping cylinder. 
   Mechanisms to adjust the height of a seat, the angle of inclination of a seat and the angle of the inclination of a backrest using a Bowden cable that is actuated by a push button are known. See for example U.S. Pat. Nos. 5,577,804 and 6,019,429 by the applicant. 
   From time to time, a cylinder may be damaged during use, or a seal may fail. In such cases, the cylinder must be replaced if the chair is to maintain its functionality. 
   SUMMARY OF THE INVENTION 
   In accordance with the instant invention, a simplified adjustment mechanism for a cylinder is provided. The adjustment member is mounted directly on the cylinder and may seat thereon. Accordingly, the adjustment mechanism is removably mounted to the cylinder. One advantage of this approach is that, if a cylinder has to be replaced, the adjustment mechanism need not be replaced. Accordingly, a serviceman may simply disengage the cylinder from the adjustment member and remove the cylinder from the chair. A replacement cylinder may then be inserted into the chair and the same adjustment member may be removably attached to the new cylinder. Accordingly, it is not necessary to disengage the cable from the adjustment mechanism. 
   Another advantage of the instant invention is that the adjustment mechanism provides a simplified construction which is suitable for mass production and, preferably, is made by molding and, more preferably, by injection molding. Accordingly, a low cost, durable adjustment member may be obtained. 
   In accordance with one aspect of the instant invention, there is provided a chair comprising:
         (a) a telescoping cylinder having a first end connected to a first portion of the chair, a second end distal to the first end and connected to a second portion of the chair, and a valve provided on the first end of the cylinder, whereby when the cylinder telescopes, the first portion of the chair is moved with respect to the second portion of the chair;   (b) an adjustment member having a moveable member that is operably connected to the valve when the adjustment member is mounted to the cylinder and the moveable member is removably mounted to the cylinder;   (c) a flexible cable extending between the actuator and the adjustment member and the moveable member is operable by movement of the flexible cable to open the valve; and,   (d) an actuator operable by a person and drivingly connected to the adjustment member.       

   In one embodiment, the adjustment member has a housing configured to be mounted to the cylinder. 
   In another embodiment, the adjustment member has a first portion having the moveable member, the housing is non-removably mounted to the cylinder and the first portion is removably mounted to the housing. 
   In another embodiment the housing includes a sleeve sized to receive therein the first end of the cylinder. 
   In another embodiment the sleeve is sized to slidingly lockingly receive therein the first end of the cylinder. 
   In another embodiment the first portion and the housing are secured together by mechanical engagement members. 
   In another embodiment the mechanical engagement members comprise screws. 
   In another embodiment the adjustment member comprises a first portion having the moveable member and the portion having the moveable member is not permanently affixed to the cylinder. 
   In another embodiment the adjustment member has a housing configured to be removably mounted to the cylinder and a first portion having the moveable member connected to the housing. 
   In another embodiment the housing includes a sleeve sized to receive therein the first end of the cylinder. 
   In another embodiment the sleeve is sized to slidingly receive therein the first end of the cylinder. 
   In another embodiment the adjustment member is made of plastic. 
   In another embodiment the adjustment member is made by molding. 
   In accordance with another aspect of the instant invention, there is provided a chair comprising an adjustment mechanism for a chair having a telescoping cylinder, the telescoping cylinder comprising a valve actuated via a flexible cable, a first end connected to a first portion of the chair and having the valve, and a second end distal to the first end and mounted to a second portion of the chair, the first portion of the chair is moveable with respect to the second portion of the chair, the adjustment member comprising a moveable member that is operated by movement of the flexible cable to open the valve wherein at least a portion of the adjustment member having the moveable member is removably mounted to the cylinder. 
   In one embodiment the adjustment member has a housing configured to receive therein the first end of the cylinder. 
   In another embodiment the housing includes a sleeve sized to receive therein the first end of the cylinder. 
   In another embodiment the adjustment member comprises a first portion having the moveable member and a second portion adapted to be fixedly mounted to the cylinder, the first portion being removably mountable to the second portion. 
   In another embodiment the first and second portions are secured together by mechanical engagement members. 
   In another embodiment the mechanical engagement members comprise screws. 
   In another embodiment the second portion of the adjustment member comprises a housing configured to receive therein the first end of the cylinder. 
   In another embodiment the housing includes a sleeve sized to receive therein the first end of the cylinder. 
   In another embodiment the sleeve is sized to slidingly lockingly receive therein the first end of the cylinder. 
   In another embodiment the adjustment member has a housing configured to be removably mounted to the cylinder and a first portion having the moveable member connected to the housing. 
   In another embodiment the housing includes a sleeve sized to receive therein the first end of the cylinder. 
   In another embodiment the sleeve is sized to slidingly receive therein the first end of the cylinder. 
   In another embodiment the adjustment member is made of plastic. 
   In another embodiment the adjustment member is made by molding. 
   In accordance with another aspect of the instant invention, there is provided a method of servicing a chair having a flexible cable that acts via an adjustment member to actuate a telescoping cylinder, the telescoping cylinder having a first end having a valve and a distal end, the method comprising:
         (a) disconnecting the adjustment member from the cylinder and disengaging the distal end of the cylinder from the chair; and,   (b) connecting the adjustment member to a replacement cylinder and engaging the distal end of the replacement cylinder with the chair.       

   In one embodiment the adjustment member has a sleeve and step (a) comprises sliding the first end of the cylinder out of engagement with the sleeve. 
   In another embodiment the chair has a seat shroud and the method further comprises removing the seat shroud to access the cylinder prior to sliding the cylinder out of engagement with the adjustment member. 
   In another embodiment the cylinder comprises part of a seat height adjustment mechanism and extends upwardly from a floor engaging chair base and step (a) includes removing the distal end from the floor engaging chair base. 
   In another embodiment the adjustment mechanism is mounted to a seat support having a lower surface and step (b) further comprises passing the first end of the replacement cylinder through the lower surface of the seat support prior to sliding the first end of a replacement cylinder into engagement with the adjustment member. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other advantages of the instant invention will be more fully and completely understood by reference to the following drawings of the preferred embodiment of the invention in which: 
       FIG. 1  is a perspective view of a chair according to a first embodiment of the instant invention; 
       FIG. 2  is a perspective view of an adjustment member mounted on the top of a cylinder according to one embodiment of this invention; 
       FIG. 3  is an exploded view of  FIG. 2 ; 
       FIG. 4  is a cross section along the line  4 - 4  of  FIG. 2  wherein the valve of the cylinder is closed; and, 
       FIG. 5  is a cross section along the lines  4 - 4  in  FIG. 2  wherein the valve of the cylinder is open. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  shows an embodiment of a pedestal or an office chair. In  FIG. 1 , the chair shown in doted outline except for the adjustment member and the top portion of the height adjustment cylinder. 
   As shown in  FIG. 1 , chair  10  comprises a seat  12 , a backrest  14 , a base  16 , a height adjustment cylinder  18  extending between base  16  and the bottom of seat  12  and arms  20  that are provided on opposite sides of seat  12 . 
   It will be appreciated that chair  10  may be of any particular design. Accordingly, in one embodiment, arms  20  need not be provided. In addition, if chair  10  comprises a stool, then a backrest  14  need not be provided. Further, seat  12  and backrest  14  may be of any particular configuration. As shown in  FIG. 1 , base  16  is a wheeled base, which is provided with a plurality of wheels  22 . While the use of a wheeled base is preferred, in another embodiment, base  16  may comprise a slide base or other suitable floor engaging portion for chair  10 . 
   For ease of reference, the invention is described in terms of the use of the adjustment member for a height adjustment cylinder  18 . Accordingly, in the embodiment of  FIG. 1 , seat  12  need not be tiltable. However, it will be appreciated that in other embodiments either or both of seat  12  and backrest  14  may be mounted as is known in the art so as to permit either or both to tilt or rock independently or synchronously. It will be appreciated that if seat and/or backrest  10  are reconfigurable at different angles that a cylinder  18  and an adjustment member as taught herein may be utilized to facilitate such movement. For example, either seat  12  and/or backrest  14  may use a cylinder  18  to control the tilt of the seat and/or backrest  14  as disclosed in U.S. Pat. No. 6,019,429 or by any other means known in the art. In any instance in which a cylinder  18  is used to control the reconfiguration of a chair, an adjustment member as disclosed herein may be used. 
   Cylinder  18  has a first end or a valve end  24  and a second end or distal end  26 . Such cylinders are generally known in the art and typically have two internal chambers that are in flow communication via a passage having a valve (not shown). When the valve is in the closed position, the chambers are isolated from each other. Accordingly, the length of the cylinder, and therefore the height of the chair or the configuration of a chair, is locked in a position. When the valve is moved to the open position, the two chambers are allowed to communicate permitting fluid to flow therebetween. Accordingly, the height of the chair or the configuration of the chair may be adjusted. Typically, a cylinder has a valve release pin  30 , which is drivingly connected to the valve of the cylinder. Accordingly, when valve release pin  30  is actuated, the valve of cylinder  18  is opened. 
   In accordance with this invention, an actuator  32 , an adjustment member  28  and a flexible cable  34  extending between actuator  32  and adjustment member  28  are provided. It will be appreciated that actuator  32  may be provided at any location on chair  12 . In a preferred embodiment shown in  FIG. 1 , actuator  32  is provided in an arm  20  of a chair. However, it will be appreciated that actuator  32  may be provided at any other location on the chair and is preferably located at a position whereby actuator  32  may be operated by a user when sitting in chair  12 . For example, actuator  32  may be provided on the side of seat  12 . It will also be appreciated that if the chair has more than one cylinder  18 , then each cylinder  18  may be operated by a different actuator  32 . In addition, in an alternate embodiment, a single actuator  32  may be used to operate two or more cylinders  18 . 
   Flexible cable  34  may be any such cable known in the art and, may be a Bowden cable. As shown in  FIGS. 4 and 5 , flexible cable  34  may be a longitudinally extending cable  36 , which is slideably received in a sheath  38 . 
   Typically, cylinder  18  is configured such that valve release pin  30  is biased to the valve closed position which is shown in  FIG. 4 . Accordingly, in order to adjust the height of chair  10  or re-configure chair  10 , valve release pin  30  must be depressed. To this end, adjustment member  28  is configured such that when cable  36  is moved by means of actuator  32 , valve release pin  30  is moved to the open position. Accordingly, actuator  32  may be of any configuration whereby, when used, actuator  32  tensions cable  36  thereby operating adjustment member  28 . When cable  36  is under sufficient tension, adjustment member  28  operates valve release pin  30  to open the valve of cylinder  18 . Such actuators are shown in U.S. Pat. Nos. 5,577,804 and 6,019,429. Any such actuator known in the art may be utilized. In a particularly preferred embodiment, actuator  32  is a button. In an alternate embodiment, it will be appreciated that actuator  32  may be a lever, a rocker switch or the like. 
   Referring to  FIGS. 2-5 , adjustment member  28  comprises a first portion  40  and a housing  42 . First portion  40  is provided with a movable member  44 . Movable member  44  is operably connected to the valve (e.g. via valve release pin  30 ) such that when cable  36  is tensioned, movable member  44  causes valve release pin  30  to move thereby opening the valve of cylinder  18 . It will be appreciated that since valve release pin  32  may be biased to the valve closed position, valve release pin  30  may be utilized to move movable member  44  back to the position shown in  FIG. 4  when the tension in cable  36  is released, such as by a user no longer pressing on actuator  32 . 
   First portion  40  may comprise at least a top member  46 . Top member  46  is configured to receive movable member  44  and permit movable member  44  to interact with valve release pin  30 . Accordingly, top member  46  may be positioned above cylinder  18  and may be provided with a central opening  48  through which movable member  44  extends downwardly to interact with valve release pin  30 . Movable member  44  has an upper portion  50 , which is engaged by cable  36 , and a lower portion  52 , which interacts with valve release pin  30 . 
   Movable member  44  may be movably mounted to top member  46  by any means known in the art. Preferably, movable member  44  is pivotally mounted to top member  46 . Accordingly, movable member may be provided with pivot pins  58  (which may be integrally molded with movable member  44 ). Top member  46  may be provided with recesses  60  that are configured to receive pivot pins  58 . Accordingly, when cable  36  is tensioned, moveable member will pivot thereby causing lower portion  52  to drivingly operate pivot pin  30 . 
   Flexible cable  34  may be drivingly connected to adjustment member  28  as shown in  FIGS. 4 and 5 . As shown therein, cable  36  may have an end cap  54  that is secured thereto. Accordingly, during manufacturing, cable  36  may be passed through opening  56  in upper portion  50  of movable member  44  and then end cap  54  may be secured thereto. End cap  54  is sized so as to prevent end cap  54  from passing through opening  56 . Accordingly, when tension is applied to cable  36 , end cap  54  will abut against movable member  50 . Top member  46  is provided with a member for permitting end cap  54  to move relative to distal end  62  of sheath  38 . For example, distal end may abut against the rear surface of wall  64 , which is opposite to moveable member  44 . Alternately, as shown in  FIGS. 2 and 3 , top member  46  may be configured to secure distal end  62  in a fixed position. Accordingly, wall  64  may be provided with a central opening for receiving and securing in place distal end  62 . Distal end  62  may be provided with an end member  66  that has a narrowed portion, which is received in the opening in wall  64 , and a disk shaped end  68 . Thus, when end member is inserted into the opening in wall  64 , disk shaped end  68  abuts against the front face of wall  64 . Accordingly, when cable  36  is tensioned, end cap  54  and top portion  50  of moveable member  44  are moved towards wall  64 . It will be appreciated that any other means for securing the distal end  62  of a Bowden cable in place may be utilized, including those means known in the bicycle art. 
   In operation, when a user actuates actuator  32  (e.g. the user presses on a button), cable  36  is tensioned and, accordingly, end cap  54  is drawn towards wall  64 . As end cap  54  can not pass through opening  56 , and as movable member  44  is pivotally mounted to top member  46 , tensioning cable  36  will cause upper portion  50  of movable member  44  to be drawn towards wall  64  (to the position shown in  FIG. 5 ). This will cause lower portion  52  of movable member  44  to press downwardly on valve release pin  30  thereby opening the valve of cylinder  18 . When pressure is released from cable  36  (e.g. a user no longer presses on actuator  32 ), then the pressure of the fluid in cylinder  18  will cause valve release pin  30  to move upwardly thereby causing upper portion  50  of movable member  44  to be pushed back to the position shown in  FIG. 4 . 
   As shown in  FIG. 3 , first portion  40  comprises a top member  46  and a lower member  70 . Preferred optional lower member  70  is essentially disk shaped having a central opening  72 . Preferably, top member  46  and lower member  70  may be secured together by any means known in the art and, are preferably removably connected together. For example, as shown in  FIG. 3 , lower portion  70  is provided with upstanding arms  74  and top member  46  is provided with a recess  76  for each arm  70 . In order to assemble first portion  40 , recesses  76  may be aligned with arms  74 . The inner top portion  78  of arm  74  may have a cam surface such that when top member  46  is lowered onto lower member  70 , arms  74  move outwardly to permit top member  46  to be placed in abutting relationship with lower member  70  and, when this position has been achieved, to move inwardly so as to abut against the upper surface  80  of top member  46 , thereby holding top member  46  in position. 
   It will be appreciated that each of movable member  44 , top member  46  and optional lower member  70  may be made of plastic and, may be made by molding, such as injection molding. Accordingly, each of the parts that make up first portion  40  may be manufactured to a high degree of quality and may be easily assembleable. 
   In accordance with a first embodiment of the instant invention, adjustment member  28  includes housing member  42 . Housing member  42  is configured to be mounted to cylinder  18 . Preferably, housing  42  is removably mounted to cylinder  18 . If first portion  40  is removably mounted to housing  42 , then housing  42  may be permanently connected to cylinder  18  or may be removably mounted to cylinder  18 . Alternately, if first portion  40  is not removably mounted to housing  42 , then housing  42  is removably mounted to cylinder  18 . Preferably, first portion  40  is removably mounted to housing  42 . 
   In a particularly preferred embodiment as shown in  FIG. 3 , housing  42  comprises a sleeve  82  which slidably receives therein first end  24  of cylinder  18 . It will be appreciated that first end  24  may be tapered. Accordingly, sleeve  82  may have a corresponding taper. 
   As shown in  FIG. 3 , sleeve  82  may have a flange  84  provided thereon (and preferably integrally molded therewith). Flange  84  may be provided with a plurality of openings  86  which are preferably threaded for receiving a screw  88 . Top member  46  and lower member  70  are each provided with openings  90  through which screw  88  may be passed. Accordingly, adjustment member  28  may be assembled by snapping top member  46  into lower member  70  and then securing first portion  40  to housing  42  by aligning openings  86  and  90  and subsequently threading screws  88  into holes  86 . It will be appreciated that first portion  40  may be removably attached to housing  42  by any other means known in the art. 
   Cylinder  18  may be incorporated into a chair by any means known in the art. For example, if cylinder  18  is a height adjustment cylinder, then the cylinder may be inserted into base  16  as is known in the art. Adjustment member  28  may be secured to the seat support mechanism of chair  10 . Accordingly, cable  36  may be secured to movable member  44  and housing  42  may be positioned at a location in which first end  24  of cylinder  18  will be received. First end  24  may then be inserted into any seat support mechanism. For example, the seat support mechanism may have an opening sized to removeably receive therein first end  24  of cylinder  18 . It will be appreciated that these operations may occur in any desired order. It will also be appreciated that housing  42  may be constructed as part of the seat support mechanism and first portion  40  may be removeably mounted thereto. 
   If cylinder  18  needs to be replaced, then a serviceman may remove second end  26  of cylinder  18  from base  16  by any means known in the art. Subsequently, the serviceman need only remove first end  24  of cylinder  18  from the seat support mechanism (not shown) by any means known in the art. For example, whether housing  42  is part of the adjustment member  28  or part of the seat support mechanism, first end  24  may be withdrawn from housing  42 , e.g. by sliding first end  24  out of housing  42 . No additional steps are required to disengage first end  24  from housing  42  as cable  36  is not affixed to cylinder  18 . Accordingly, it is not necessary to disengage cable  36  from movable member  44  or to otherwise disassemble adjustment member  28 . 
   In accordance with an alternate embodiment of the instant invention, it will be appreciated that housing  42  may be replaced with cylinder  18 . In such a case, first portion  40  is removably mounted to housing  42 . Accordingly, first end  24  may be non-removably mounted to cylinder  18  such as by being slidingly lockingly received in sleeve  82 . According to this alternate embodiment, when cylinder  18  is to be replaced, first portion  40  must be disconnected from housing  42  (e.g. by removing screws  88 ). Housing  42  and cylinder  18  may then be removed and a replacement cylinder  18  and replacement housing  42  may be inserted into the chair. First portion  40  may then be removably mounted to the replacement housing  42  such as by aligning holes  86 ,  90  and inserting screws  88 . In this alternate embodiment, it will be appreciated that additional disassembly of chair  10  may be required.