Abstract:
An armrest assembly for a chair which can be adjusted in multiple aspects with the use of single actuating mechanism. The adjustment aspects of the preferred embodiment include a vertical adjustment with respect to the chair and a horizontal rotational adjustment. Such an armrest assembly can include an armrest base securable to a chair and having a tubular portion, a hollow armrest support slideably and rotationally disposed about the tubular portion and an armpad attached to the top of the hollow armrest support. A handle to disengage the actuating mechanism is provided.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to armrests for chairs and more particularly, to an armrest assembly which is adjustable in a plurality of aspects. 
     A wide variety of adjustable office chairs are presently available. In an attempt to adapt the chair to a particular user or task, various adjustment mechanisms have been provided. Such chairs may, for example, include vertically adjustable seat height mechanisms, swivel tilt mechanisms, and adjustable back height mechanisms. Additionally, such chairs may be provided with adjustable armrest assemblies. Many such chairs have been provided which have an adjustable height armrest, such as those described in U.S. Pat. No. 5,393,125 to Watson, et al. Other such chairs have armrests which can be adjustable laterally to effect the spacing between the armrests, or armrests which can be rotated in towards the user or out away from the user. It is also known for an armrest to provide adjustments in multiple aspects, such as his disclosed in U.S. Pat. No. 5,439,267 to Peterson, et al., which discloses an armrest assembly wherein the armrest can be adjusted vertically and an armpad portion of the armrest can be moved laterally, and U.S. Pat. No. 6,053,578 to van Hekken, et al, which discloses an armrest which can be adjusted laterally, vertically, forwards and backwards and rotationally. The van Hekken, et al. patent is owned by the assignee of this application. 
     One concern with armrests which are adjustable in multiple aspects is that each such adjustment requires the user to initiate adjustment in each aspect using different adjustment mechanisms. This can be cumbersome for the user in that an adjustment in one aspect may affect the desired adjustment in another aspect, requiring multiple adjustments for each aspect until a comfortable position is achieved. Therefore, a need exists for an armrest providing a single mechanism which controls the adjustment of two or more aspects of the armrest, thereby allowing two or more aspects to be adjusted at the same time. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an armrest assembly securable to a chair and simultaneously adjustable in two or more aspects with a single adjustment mechanism. Specifically, the armrest assembly disclosed herein provides for vertical height adjustment and rotational positioning using a single adjustment mechanism which is easily accessible to the user when the user&#39;s arm is in a resting position on the armrest. 
     The armrest assembly having features of the present invention described above includes a base having a means for attaching the armrest to the underside of the seat of a chair or to the frame of a chair. The base is connected to a tubular vertical post. The vertical post has an array of recesses aligned in rows and columns on one side thereof. A shroud is slideably and rotatably disposed on the vertical post. The shroud houses a locking mechanism consisting of a bar having a plurality of pins inserted therethrough which engage the recesses defined on the tubular vertical post, thereby locking the armrest in place. The pins are locked in place and released by a second bar which slides up and down adjacent to the first bar. The second bar has indentations defined therein to allow the pins to be disengaged from the recesses when the portion of the second bar having the indentations is positioned over the pins. An armpad portion is attached to the top of the slideable shroud portion. When a handle connected to the second bar is engaged by the user, the plurality of pins are disengaged from the recesses on the post, thereby allowing the shroud and armpad portions of the armrest to be adjusted vertically and rotated about a point approximately in the center of the armrest. When the desired position has been achieved, the user disengages the handle, thereby allowing the pins to engage the corresponding recesses on the tubular vertical post nearest the selected position, locking the armrest into position with respect to the post. 
     Other details, objects and advantages of the inventions will become apparent from the following detailed description and accompanying drawings of the present preferred embodiments thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a chair with the armrest assembly of the current invention attached thereto. 
     FIG. 2 shows an exploded detailed view of the armrest assembly of the current invention. 
     FIG. 2 a  shows an exploded view of the locking mechanism of the current invention. 
     FIG. 2 b  shows an enlargement of the locking bar and pins of the locking mechanism of FIG. 2 a  rotated 180 degrees for clarity. 
     FIG. 3 shows a front elevational view of the armrest in a lowered position. 
     FIG. 4 shows a cross-section of the armrest assembly of FIG. 3 having the locking mechanism engaged. 
     FIG. 4 a  shows a cross-section of the armrest assembly of FIG. 3 having the locking mechanism disengaged. 
     FIG. 5 shows a front elevational view of the armrest assembly of the current invention in an extended position. 
     FIG. 6 shows a cross-sectional view of the armrest assembly of FIG. 5 having the locking mechanism engaged. 
     FIG. 7 shows a right side elevational view of the armrest assembly of the current invention. 
     FIG. 8 shows a cross-sectional view of a portion of the armrest assembly of FIG. 7 showing the locking mechanism in an engaged position. 
     FIG. 9 shows a right side elevational view of the armrest assembly of the current invention in the extended position. 
     FIG. 10 shows a cross-sectional view of a portion of the armrest assembly of FIG. 9 showing the locking mechanism in a disengaged position. 
     FIG. 11 shows a top view of the armrest assembly of the current invention illustrating in phantom lines, the rotational limits of the armpad. 
    
    
     DETAILED DESCRIPTION 
     Referring now to the various figures, where like reference numbers refer to similar parts throughout the several views, FIG. 1 shows a pair of armrests  10  of the current invention attached to a chair. FIGS. 2,  2   a  and  2   b  show exploded and detailed views of the preferred embodiment of the current invention. The armrest assembly consists generally of base  12  comprising an attachment member  14  configured to be connected to the base or frame of a chair with a securing mechanism (not shown). Connected to attachment member  14 , and generally formed as one piece with attachment member  14  is vertical member or post  16 , which in the preferred embodiment is tubular in shape, although any shape could be used. Defined on post  16  is a plurality of recesses  18 , which in the preferred embodiment, are concave in shape and arranged in rows and columns. In the preferred embodiment, there are thirty-six recesses  18 , arranged in nine rows of four recesses each, however, any number of rows and columns of recesses  18  may be utilized. 
     The moveable portion  26  of the armrest assembly comprises a generally cylindrical hollow shroud member  27  topped by member  31 . Armpad  60  is secured to the top of shroud member  27  via a plurality of screws (not shown) which extend up through holes  28  in member  31 . Defined on one side of shroud member  27  is housing  29  which houses locking mechanism  40 . Hollow area  32  defined by shroud member  27  accepts post  16  of base  12 , allowing moveable portion  26  to move vertically and rotate laterally with respect to base  12 . Post  16  has bearings  20 , disposed in grooves defined therein to aid in the tightness of fit of movable portion  26 . Defined on the interior diameter of hollow  32  is groove  33 , which is preferably rectangular in shape. Stop member  22 , connected to the top of post  16  by screw  23 , defines tongue  19  thereon. Tongue  19  engages groove  33  to limit the rotational and vertical movement of moveable portion  26  with respect to base  12 . In addition, the orientation of stop member  22  controls the amount of rotation of armrest  10 . By orienting member  22  180 degrees to that shown in FIG. 2, all rotation of the armrest  10  can be eliminated. Likewise, by orienting member  22  only 90 degrees, or by changing the thickness of tongue  19 , the degree or limits of rotation of armrest  10  can be altered. An example of the possible range of rotational motion available to movable portion  26  is shown in FIG. 11, and an example of the range of vertical movement is shown by comparing FIGS. 3 and 7 with FIGS. 5 and 9. Note that these figures are in no way meant to limit the scope of the invention to the ranges of movement shown therein. 
     Locking mechanism  40  comprises bar  42 , which may be rectangular in shape, best shown in FIG.  2 . Bar  42  defines a plurality of holes  41  located, in the preferred embodiment, at the bottom portion of bar  42 . A corresponding plurality of pins  48  are slideably disposed within holes  41 . Bar  42  is preferably composed of glass-reinforced nylon and is made as a single piece using an injection molding process well known to those of ordinary skill in the art. 
     Pins  48 , which are slideably disposed in holes  41  defined in bar  42 , are shaped having top member  57  slightly larger than body member  58  such that the pins cannot extend completely through holes  41 . Additionally, pins  48  preferably have a convex end  56  opposite top member  57 . Convex end  56  is shaped and sized to mate with recesses  18  defined in post  16 . In the preferred embodiment, the number of holes  41  and pins  48  is four, however, any number of holes and pins may be utilized. Preferably, pins  48  are composed of glass-reinforced nylon and are made using an injection molding process. When in place in housing  29 , pins  48  engage a corresponding number of recesses  18  to inhibit the movement of movable member  26  with respect to base  12 . 
     Locking bar  44 , which is rectangular in shape and complements bar  42  in shape, holds pins  48  in a locked engagement with recesses  18  when in a locked position. Locking bar  44  is preferably one-piece and preferably composed of glass-reinforced nylon and is manufactured using an injection molding process. Toward the lower portion of locking bar  44  are defined a plurality of indentations  43 , corresponding to the number of pins  48  which have been utilized. For each pin  48 , a corresponding indentation  43  having a deep area  62 , a sloped area  64  and a shallow area  63  is utilized. Indentations  43  are divided vertically by divider  65 . Features of locking bar  44  are best shown in FIG. 2 b . Locking bar  44  contacts bar  42  on surfaces  51  and is able to slide along bar  42  to an up, unlocked position, or a down, locked position. Spring  50  biases bar  42  in a down, locked position. 
     When in an up, unlocked position, indentations  43  in locking bar  44  allow pins  48  to disengage from recesses  18 , thereby allowing moveable portion  26  to move simultaneously both vertically and rotationally with respect to base  12 . Each of indentations  43  has two flat areas,  62  and  63 , sized to accept the top portions  57  of pins  48 . The flat areas  62  and  63  of indentations  43  are of differing depths, with area  62  being deeper than area  63 . Areas  62  and  63  are connected via sloped area  64 . This is best shown in FIG. 2 b  and in cross-section in FIG.  4 . Locking bar  44  is able to slide up and down adjacent bar  42  on surfaces  51 , allowing indentations  43  to act as a wedge and be positioned over the top portions  57  of pins  48 . When bar  44  is in an up, unlocked position, pins  48  are allowed to enter deep area  62  of indentations  43 , thereby disengaging from recesses  18  on post  16 . As locking bar  44  slides into a down, locked position, sloped area  64  of indentations  43  forces pins  48  into engagement with recess  18  by a wedging-type action. When locking bar  44  is completely in a down position, pins  48  are fully engaged in recesses  18  and are locked in position by shallow area  63  of indentations  43 . 
     Integral to locking bar  44  is boss  49 , located on the top thereof and actuator  45 , best shown in FIG. 2 b . Spring  50  is held in place on top of locking bar  44  by boss  49 , and on the bottom of header member  52  by a circular depression (not shown). Spring  50  biases locking bar  44  in a down, locked position, thereby causing pins  48  to be pushed through holes  41  in bar  42  to engage recesses  18 , as described above. 
     Header member  52 , which is generally T-shaped, is held in place by screws  54  which engage holes  30  in moveable portion  26 . Header member  52  holds bar  42 , locking bar  44  and spring  50  in place within housing  29 . Actuator  45  extends through a hole defined in housing  29  (not shown). Ergonomic handle  46  fits over actuator  45  to allow the user of the chair to manually move locking bar  44  into a unbiased position. When in this unbiased position, pins  48  are pushed into deep area  62  of indentations  43  in bar  44  by any movement of movable member  26  by virtue of the convex/concave mating surface between pins  48  and recesses  18 . When pins  48  are in this disengaged position, the entire movable portion  26  of armrest assembly  10  is able to be moved vertically and also rotated, to simultaneously adjust the vertical height and rotational position to armpad  60 . 
     In an engaged, locking position, as best shown in the cross sectional views of FIGS. 4,  6  and  8 , locking bar  44  is biased in a downward position within housing  29  by spring  50 , causing shallow area  63  of indentations  43  to push pins  48  securely against bar  42 . Convex ends  56  of pins extend through holes  41  in bar  42  and engage a corresponding plurality of recesses  18 , depending upon the position of moveable portion  26  chosen by the user. Preferably, there will be a large number of recesses  18 , thereby allowing a wide range of possible positions for movable portion  26 . When the user wishes to change the vertical or rotational position of armrest  60 , actuator  45  with handle  46  is pulled upward. Any movement of moveable portion  26  forces pins  48  into deep area  62  of indentations  43  defined in locking bar  44 . This is best illustrated in the cross sectional views of FIGS. 4 a  and  10 . With pins  48  no longer engaged with recesses  18  of post  16 , moveable portion  26  is free to move vertically and rotationally. When the user is satisfied with the positioning of armpad  60 , handle  46  is released and spring  50  biases bar  44  into the down, locked position. Pins  48  are forced through holes  41  by wedging action of sloped areas  64  of indentations  43 , and are held in the locked position by the shallow area  63  of indentations  43 . Moveable portion  26  may be moved slightly such that pins  48  are able to seek the nearest set of recesses  18  on post  16  corresponding to the selected position. Stop member  22  prevents moveable portion  26  from moving to an area having no recesses  18  defined therein. 
     While certain embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular embodiments disclosed herein are intended to be illustrative only and not limiting to the scope of the invention, which should be awarded the full breadth of the following claims and any and all embodiments described thereby.