CROSS-REFERENCE TO RELATED APPLICATIONS 
   The subject application claim the benefits of U.S. Provisional Application Ser. No. 60/513,787, filed Oct. 23, 2003 and U.S. Provisional Application Ser. No. 60/513,788, filed Oct. 23, 2003. These applications are herein incorporated by reference in their entirety. 


   BACKGROUND OF THE INVENTION 
   Modern work chairs are ergonomically designed with the primary objective of preventing health problems resulting from inappropriate postural positioning of the seated worker, and also the numerous health problems resulting from static work postures over an extended period of time. Many of the remedies afforded by these ergonomic innovations involve either active or passive adjustments for selectively changing the postural positioning by the seated worker. Oftentimes ergonomic posture positioning adjustments have the added advantage of fitting the chair to multiple users having different body measurements, and also of allowing individual users the adjustment options for working at various height work surfaces. Similarly, these chair adjustments oftentimes allow seated workers to adjust their chairs for access to various height-placed work objects such as microscopes set on high counters for part of the work day, and then for example, a keyboard set at a much lower height for another part of the work day. Height adjustment is the most often used chair adjustment in the seated workplace. 
   Also, modern work chairs have been continually designed and redesigned to make them comfortable for seated workers, as worker comfort translates to worker productivity. Modem work chairs now offer seats of breathable fabrics, lumbar supports, sculpted seat cushions, and adjustable backrests and footrests. Modern work chairs provide many of these features while maintaining a sleek and attractive overall design. 
   Persons confined to a wheelchair experience more health problems relating to postural stasis than ordinary seated workers, and seldom are able to utilize any of the ergonomic benefits, or stylish design attributes afforded ordinary workers in the seated workplace. A wheelchair-type chair with the ergonomic innovations and design attributes of a modern work chair would offer a user approximately the same health and comfort benefits as those provided an ordinary seated worker, while providing conformity with the style and design of the overall workplace environment. 
   All patents, patent applications, provisional patent applications and publications referred to or cited herein, are incorporated by reference in their entirety to the extent they are not inconsistent with the explicit teachings of the specification. 
   SUMMARY OF THE INVENTION 
   The invention involves a wheeled work chair. The chair can gave the ergonomic functions and style of a modern work chair yet be equipped with wheelchair-type supporting wheels. This allows a disabled person to move about a workplace without use of his or her feet. In a preferred embodiment, the chair is height adjustable with the upper portion of the chair moving relative to the lower portion of the chair, with the wheels attached to the upper portion. In this embodiment, the wheels move with the chair seat as the height of the chair is adjusted, thus allowing the seat to spin about in concert with the wheels. This allows the user to benefit from the swivel features of modern work chairs without the typical problem that would be experienced with standard wheelchairs, that being the bumping of user&#39;s legs into stationary wheels during chair seat spin. In one embodiment where the wheels are connected to the lower portion of the wheeled work chair, approximately the same swivel limitations as standard wheelchairs exist, because as the wheels remain stationary on the ground whether the height of the chair is adjusted or not, the user&#39;s legs would swivel into the stationary wheels, unless the chair seat were adjusted high enough over the wheels to clear obstruction with the stationarily grounded wheels. In a particularly preferred embodiment of the wheeled work chair, whether the wheels are secured to the upper portion or the lower portion, a pair of push-off arm rests are provided allowing the user to transfer her or his weight from the chair seat making up the upper portion of the chair, to the base making up the lower portion of the chair. This allows an assistant to raise the chair seat, or add an additional seat cushion without user evacuation from the chair. In a most preferred embodiment, a remote actuator is provided proximate one of the push-off arm rests which allows the user to raise the chair seat without using his or her feet, without evacuating the chair, and without assistance from another person. An example of benefitting from this most preferred embodiment is that a worker confined to a chair can move herself or himself from a desk work area, over to a copy machine, and raise himself or herself to a height required to operate the copy machine without assistance from another person. In a home or community environment, this most preferred embodiment would allow a user to reach and access many essential objects that might otherwise be impossible in a standard wheelchair. This most preferred embodiment is also helpful in assisting the user to transfer from the wheeled work chair to a bathtub, another chair, into a car seat, or onto a bed. In an hospital or nursing home environment, this most preferred embodiment would serve to assist a healthcare worker, or the user, independent of a healthcare worker, into a height positioned bed or gurney. In an other version of this most preferred embodiment, a second remote actuator is mounted on the upper portion of the wheeled work chair allowing a user to adjust the chair downward. In yet another version, any number of remote actuators can be mounted on upper portion armrests for actuating seat tilt, back tilt, footrest adjustments, or any other ergonomic mechanisms the wheeled work chair might provide. 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a side view of a preferred embodiment of the wheeled work chair of the subject invention with the wheels connected to the upper portion of the chair. 
       FIG. 2  shows a front view of the wheeled work chair shown in  FIG. 1 . 
       FIG. 3  shows a side view of the wheeled work chair shown in  FIG. 1  where the height of the chair has been adjusted upward. 
       FIG. 4  shows a front view of the wheeled work chair shown in  FIG. 1  where the height of the chair has been adjusted upward. 
       FIG. 5  shows a front view of another preferred embodiment of the wheeled work chair of the subject invention that has adjustable push-off arm rests. 
       FIG. 6  shows a front view of the wheeled work chair shown in  FIG. 5  where the height of the chair has been adjusted upward. 
       FIG. 7  shows a side view of another preferred embodiment of the wheeled work chair of the subject invention. 
       FIG. 8  shows a front view of another preferred embodiment of the wheeled work chair of the subject invention with the wheels connected to the lower portion of the chair. 
       FIG. 9  shows a side view of another preferred embodiment of the wheeled work chair of the subject invention with the wheels connected to the upper portion of the chair. 
       FIG. 10  shows a side view of another preferred embodiment of the wheeled work chair of the subject invention with the wheels connected to the lower portion of the chair. 
       FIG. 11  shows another preferred embodiment of the wheeled work chair of the subject invention with the wheels connected to the lower portion of the chair which includes a base with upwardly extending legs. 
       FIG. 12  shows a side view of another preferred embodiment of the wheeled work chair of the subject invention with the wheels connected to the upper portion of the chair. 
       FIG. 13  shows a side view of the wheeled work chair shown in  FIG. 12  with the wheels connected to the lower portion of the chair. 
       FIG. 14  shows a side view of the wheeled work chair shown in  FIG. 12  with the wheels connected to the lower portion of the chair. 
       FIG. 15  shows a side view of another preferred embodiment of the wheeled work chair of the subject invention with the wheels connected to the upper portion. 
       FIG. 16  shows a side view of the wheeled work chair shown in  FIG. 15  with the wheels connected to the upper portion. 
       FIG. 17  shows a side view of the wheeled work chair shown in  FIG. 15  with the wheels connected to the lower portion. 
       FIG. 18  shows a side view of the wheeled work chair shown in  FIG. 15  with the wheels connected to the lower portion. 
       FIG. 19  shows a side view of another preferred embodiment of the wheeled work chair of the subject invention with the wheels connected to the lower portion. 
       FIG. 20  shows a side view of another preferred embodiment of the wheeled work chair of the subject invention with the wheels connected to the upper portion. 
       FIG. 21  shows a side view of the wheeled work chair shown in  FIG. 20  with the seat position adjusted upward. 
       FIG. 22  shows a side view of another embodiment of the wheeled work chair shown in  FIG. 20  with the wheels connected to the lower portion. 
       FIG. 23  shows a side view of the wheeled work chair shown in  FIG. 22  with the seat position adjusted upward. 
       FIG. 24  shows another preferred embodiment of the wheeled work chair of the subject invention. 
       FIG. 25  shows another preferred embodiment of the wheeled work chair of the subject invention. 
   


   DETAILED DESCRIPTION OF THE INVENTION 
   The subject invention provides a wheelchair without the traditional frame. The wheeled work chair of the subject invention provides the ergonomic benefits, comfort, and style of a conventional office chair. 
   The subject invention has a lower portion and an upper portion that can move relative to the lower portion. The subject invention has an height adjustment mechanism  11  supported on the lower portion which supports and moves a seat support mechanism to adjustable heights. The seat support mechanism positionally supports a chair seat. 
   The subject chair has wheelchair-type wheels mounted to a chair. The chair is height adjustable to adapt to different task ergonomic configurations. An upper portion moves relative to the lower portion of the chair. Wheels mounted on the stationary, lower portion do not rise on height adjustment. Wheels mounted on the upper moving portion rise with the chair seat and leave the ground as the chair is adjusted upward. To accomplish height adjustment for a seated person who is unable to use their legs the subject chair can be fitted with a push-off arm rest supporting mechanism. The push-off arm rest supporting mechanism  42  is stationarily supported directly by the lower portion allowing a person to transfer their body weight with their arms to the lower portion thereby allowing the seat to be raised. 
   A preferred embodiment of the chair of the subject invention is shown in  FIGS. 14 . In this embodiment, the wheels  10  are mounted on the upper portion  12  of the chair. Therefore, when the height of the chair is adjusted upward, the wheels rise off the ground. The upper portion comprises a seat support mechanism  14  and a chair seat  16 . The upper portion can further include a seat back  18  and arms  20 . The upper portion  12  moves relative to the lower portion  22 . The lower portion  22  includes a base  24  with at least three castors  26  which contact the floor. A swivel  27  can be included in the lower portion  22  to allow the push-off arm rest supporting mechanism to rotate. 
   Wheels are attached to the chair by a wheel supporting mechanism  28 . Wheel support members  30 ,  32  connect to the upper portion  12  or lower portion  22  of the chair and extend in opposite directions from each other. A first end  34 ,  36  of each wheel support member  30 ,  32 , respectively, attaches to the chair. A second end  38 ,  40  of each wheel support member  30 ,  32 , respectively, receives the wheels  10 . The wheels rotate substantially parallel to each other and cannot swivel in relationship to one another. 
   In a particularly preferred embodiment, the wheeled work chair of the subject invention has a push-off arm rest supporting mechanism  42  that includes a pair of push-off arm rests  56 ,  58  which allows one seated on the chair to use for lifting their weight off the chair seat  16  so the seat can be raised. The push-off arm rest supporting mechanism is attached to the lower portion  22 . The push-off arm rest supporting mechanism  42  includes push-off arm rest supports  44 ,  46 . A first end  48 ,  50  of each support  44 ,  46  respectively, is secured to the lower portion  22 . A second end  52 ,  54  of each support  44 ,  46  has push-off arm rests  56 ,  58 . The push-off arm rests do not rise with the upper portion of the chair as the upper portion rises. The push-off arm rests can be detachable. Slots  59  allow upper portion components attached to the push-off arm rest supports to rise as the upper portion rises. 
   In the embodiment shown in  FIG. 1 , an actuation mechanism  60  locks and unlocks the height adjustment mechanism which controls movement of the upper portion  12  relative to the lower portion  22 . The actuation mechanism  60  can be any type suitable to control the height adjustable mechanism. In this embodiment, the height adjustment mechanism  11  is a telescoping support mechanism  61  with an upper section  63  and a lower section  65  which move in parallel alignment and can be locked into position or unlocked for height adjustments. The actuation mechanism  60  controlling movement of these sections in this embodiment is a remote actuation mechanism using a lever  13  and a cable  15 . An additional actuator  62  is shown on the chair in  FIG. 1  and controls the tilt and positioning of the seat  16  and seat back  18 . 
   As previously stated,  FIGS. 1-4  show a preferred embodiment of the subject chair with the wheels mounted on the upper moving portion.  FIG. 1  shows a side view of the chair with the wheels  10  on the ground.  FIG. 2  shows a front view of the same chair in that position.  FIG. 3  shows a side view of the subject chair where the seat has been raised. The upper portion  12  of the chair including the seat support mechanism  14 , the seat  16 , the seat back  18 , arms  20  and wheels  10  have moved within the slots  59  and away from the lower portion  22 . With the wheels  10  raised off the ground the chair seat can swivel. 
     FIG. 5  shows another preferred embodiment of the wheeled work chair of the subject invention. The wheels  10  like the wheels on the chair in  FIG. 1  are connected to the upper moving portion  12  of the chair.  FIG. 5  shows the wheels on the ground.  FIG. 6  shows the chair seat raised and the wheels off the ground. An actuation mechanism  64  is a lever that contacts an actuation button  66  on a telescoping support mechanism  61  to raise and lower the chair seat  16 . The telescoping support mechanism can be supported by a stand tube  67 . In this embodiment, the push-off arm rest supports  44 ,  46  are height adjustable and can be raised or lowered. 
   Another preferred embodiment of the wheeled work chair of the subject invention is shown in  FIG. 7 . The subject chair, unlike conventional wheelchairs, does not have a traditional chair four-point frame supporting four wheels. 
     FIG. 8  shows a front view of another preferred embodiment of the wheeled work chair of the subject invention. In this embodiment, the wheels  10  are connected to the lower portion  22  of the chair and do not rise when the upper portion  12  moves away from the lower portion. 
     FIG. 9  shows another preferred embodiment of the subject invention. The wheels  10  are attached to and rise with the upper portion  22 . This embodiment includes a footrest  70  to support the feet of a person seated in the chair (U.S. Pat. No. 6,196,631).  FIG. 10  shows a similar chair where the wheels  10  are attached to the lower portion  22  of the chair.  FIG. 11  shows a chair with a footrest  70  and wheels attached to the lower portion  22  which has a base  24  with three upwardly extending legs  71 . 
     FIGS. 12-14  show another preferred embodiment of the chair of the subject invention. The chair (U.S. Pat. Nos. 5,186,519 and 5,330,254) has an upper portion  12  that moves relative to a lower portion  22 .  FIG. 12  shows the wheels  10  attached to the upper portion  12  of the chair which rises away from the lower portion  22  and base  24 .  FIGS. 13 and 14  show the wheels  10  attached to the lower portion  22  of the chair. 
     FIGS. 15-18  show another preferred embodiment of the height adjustable chair of the subject invention. The chair has push-off arm rests  56 ,  58 , not shown, supported by push-off arm rest support  44 ,  46 , not shown. A remote actuation mechanism  60  controls motion of the upper portion.  FIGS. 15 and 16  show the wheels  10  connected to the upper portion  12  of the chair.  FIGS. 17 and 18  show the wheels  10  connected to the lower portion of the chair. 
     FIG. 19  shows another preferred embodiment of the wheeled work chair of the subject invention. This embodiment has two telescoping support mechanisms  72 ,  74 . The wheels  10  are attached to the lower portion  22  of the chair. 
     FIGS. 20-23  show another preferred embodiment of the wheeled work chair of the subject invention. The chair (U.S. Pat. Nos. 6,439,657 and 6,702,372) includes an upper portion  12  that moves relative to a lower portion  22 . The upper portion includes a seat support mechanism  14 , a chair seat  16  and a seat back  18 . The lower portion includes a base  24  on castors  26  and a pivoting knee pad  76 . The push-off arm rests have a remote actuator  60  and are secured to the lower portion  22 .  FIGS. 20 and 21  show the wheels connected to the upper portion of the chair.  FIG. 21  shows the chair when the seat position has been moved.  FIGS. 22 and 23  show the wheels connected to the lower portion of the chair.  FIG. 23  shows the chair when the seat position has been moved. 
     FIG. 24  shows another preferred embodiment of the wheeled work chair of the subject invention where the wheels are connected to the upper portion of the chair.  FIG. 25  shows another preferred embodiment where the wheels are supported directly by the lower portion  22  with wheel support members  30 ,  32 , not shown. The push-off arm rests  56 ,  58 , not shown, are likewise supported directly by the lower portion and do not pivot. 
   It is understood that the foregoing examples are merely illustrative of the present invention. Certain modifications of the devices and/or methods employed may be made and still achieve the objectives of the invention. Such modifications are contemplated as within the scope of the claimed invention.
A wheel work chair has all the attributes and style of an office chair but is equipped with wheelchair-type supporting wheels The chair is height adjustable with the upper portion of the chair moving relative to the lower portion of the chair. Wheels connected to the upper portion of the chair move with the chair seat as the height of the chair is adjusted. Wheels connected to the lower portion of the chair remain on the ground as the height of the chair is adjusted. A static surface is provided on the arm of a height adjustable chair to support the weight of a user while that chair is being raised.