Abstract:
A tray assembly mounted on a wheelchair. A housing containing the tray is mounted along the side of the chair arm. The tray assembly has a tray surface moveable between a stowed and unstowed position.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. nonprovisional patent application Ser. No. 11/871,454, entitled “Folding Armrest Tray for Wheelchairs,” filed on Oct. 12, 2007, which claims priority to U.S. provisional patent application No. 60/829,220, entitled “Folding Armrest Tray for Wheelchairs,” filed on Oct. 12, 2006, the contents of which are herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to devices for assisting people confined to wheelchairs and the like. More specifically, it relates to a folding armrest and tray assembly. 
     2. Descriptions of the Prior Art 
     Individuals with disabilities using power wheelchairs often have limited reach and are unable to use traditional desks and tables. In some environments, such as restaurants and the workplace, these individuals use trays attached to their wheelchair for convenience and accessibility. While there are many wheelchair trays on the market, none store out of the way when not in use without increasing the width/dimensions of the wheelchair, which interferes with accessibility. Most designs are rigid, one-piece designs that are bulky and do not fit the user. The problem is that these trays are fixed and require assistance to attach and detach. Moreover, they must be stored elsewhere on the wheelchair when not in use. 
     Accordingly, there is a need for a lightweight tray that is simple to use and is integrated into the ergonomic armrest design of commercially available wheelchairs. However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the art how the limitations of the art could be overcome. 
     SUMMARY OF INVENTION 
     The long-standing but heretofore unfulfilled need for a lightweight tray that is simple to use and is integrated into the ergonomic armrest design of commercially available wheelchairs is now met by a new, useful, and nonobvious invention. 
     The integrated wheelchair-armrest provides a mechanism to store a portable tray surface, computer, or communication device ideal for use with a wheelchair. The articulating tray is disposed within a housing which is designed to accommodate most commercially available wheelchairs. In a first embodiment, the articulating tray includes a rotating support, a base plate pivotally connected to the rotating support, the base plate adapted to pivot between a first position and second position. A tray support is pivotally connected to the base plate. The tray support is adapted to pivot between a first position and a second position. A tray is connected to the tray support. 
     In a second embodiment, a housing is adapted to encompass the tray when it is in a stowed position. The housing is further adapted to be affixed to the side of most commercially available wheelchairs, thereby providing substantially universal use of the device. 
     In a third embodiment, the tray is releasably connected to the tray support. Moreover, the tray is slidingly connected to the tray support and is moveable between a first position and a second position. The tray of an embodiment is adapted to incline and is height adjustable. 
     In yet another embodiment, the armrest includes a housing having a first side, a second side, a front, a back, a bottom, and a pivoting armrest collectively forming a hollow rectangular structure when the pivoting armrest is in a closed position. A tray support arm is pivotally and hingedly connected to the housing. While stowed, the support arm is in a vertical repose position within the housing. The support arm hingedly rotates from the stowed position to a second unstowed position outside of the housing. Once out of the housing, the rotating support arm is free to pivot in a horizontal plane. 
     A tray is slideably and hingedly connected to the support arm. The tray is slideably extended and retracted and hingedly opened and closed while in the second unstowed position outside of the housing. Moreover, the tray includes an inner portion that is hingedly connected to the outer portion and is adapted to tilt. A bracket is used to secure the inner portion of the tray in the upright tilted position. 
     To use the tray, a user pivots the armrest to the open position and rotates the support arm and tray assembly into the second unstowed position. Once in the second unstowed position, the user can adjust the location of the tray by either pivoting the support arm in a horizontal plane or sliding the tray along the support arm in a horizontal plane. The user may also open and close the tray between a horizontal plane and a vertical plane. Moreover, the user may tilt the inner portion of the tray upwardly and secure it in place. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which: 
         FIG. 1  is a side view of the invention in the stowed position, wherein the base plate is in the first position; 
         FIG. 2  is a side view of the invention in the transition position wherein the base plate is in the second position and the tray support is in the first position; 
         FIG. 3  is a perspective view of the invention in the deployed position wherein the tray support is in the second position and the tray and rotating support are in their respective first positions; 
         FIG. 4  is a perspective view of the invention wherein the tray is in the second position; 
         FIG. 5  is a perspective view of the invention wherein the rotating support is in the second position; 
         FIG. 6  is a perspective view of an alternate embodiment wherein the tray is hingedly connected to the tray support and the rotating support is telescopically connected to the housing; 
         FIG. 7  a perspective view of an alternate embodiment of the tray assembly depicting the tray in the stowed position; 
         FIG. 8  is a perspective view of an alternate embodiment of the tray assembly depicting the tray in the stowed position; 
         FIG. 9  is a side view of an alternate embodiment of the tray assembly depicting the tray in a vertical plane; 
         FIG. 10  is a front view of an alternate embodiment of the tray assembly depicting the tray in a horizontal plane; 
         FIG. 11  a front view of an alternate embodiment of the tray assembly depicting the tray in a vertical plane; and 
         FIG. 12  is a perspective view of an alternate embodiment of the tray assembly depicting the tray in the second unstowed position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof, and within which are shown by way of illustration specific embodiments by which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the invention. 
     In a first embodiment, the invention includes an articulating tray for use with a wheelchair. Referring now to  FIG. 1 , wherein tray  20  is shown in the stored position and is encompassed by housing  30  (housing  30  is depicted with the cover removed). In the embodiment of  FIG. 1 , anchor  40  is attached to the interior of housing  30 . Anchor  40 , however, can also be attached to numerous other structures without departing from the scope of the invention. For example, anchor  40  can be affixed directly to the wheelchair such as in embodiments where housing  30  is not used. 
     Rotating support  50  is pivotally connected to anchor  40  such that rotating support  40  pivots along a central axis between a first position, as depicted in  FIGS. 1-4 , and a second position, as depicted in  FIG. 5 . Base plate  60  is pivotally connected to rotating support  50  and is adapted to rotate between a first position ( FIG. 1 ) and second position ( FIGS. 2-6 ) along an axis that is substantially perpendicular to the axis of rotation of rotating support  50 . 
     Tray support  70  is hingedly connected to base plate  60 . In an embodiment, tray support  70  is connected to base plate  60  by a friction hinge. As used herein, a friction hinge is a hinge which exerts torque between two parts on a common axis. Alternatively, the use of other hinges is within the scope of the invention. For example, tray support  70  can be connected to base plate  60  by a detent hinge; a device which allows repeatable “soft stops” in one or more positions between two parts on a common axis. In this manner, tray support  70  rotates between a first position ( FIGS. 1 and 2 ) and a second position ( FIGS. 3-6 ). 
     Tray  20  is slidingly connected to tray support  70  in a preferred embodiment. This sliding engagement allows tray  20  to move between a first position ( FIG. 3 ) and a second position ( FIG. 4 ).  FIG. 5  illustrates an alternative position of tray  20  wherein the assembly is rotated around rotating support  50  such that rotating support is in its second position. This places tray  20  to side of the wheelchair. 
     In an embodiment, depicted in  FIG. 6 , tray  20  is also hingedly connected to tray support  70 . This permits the angle of tray  20  to be adjusted. While the use of a friction hinge is preferred, any type of hinge can be used as will be appreciated by one of ordinary skill in the art. The embodiment of  FIG. 6  also shows a modified rotating support  50  telescopically connected to anchor  40 . This arrangement allows the height of the tray to be adjusted. It also preferable to provide a quick-release connection between tray  20  and tray support  70  to allow tray  20  to be removed and replace with either a new tray or other device (such as a modified laptop computer). 
     As it will be appreciated, tray  20  provides the majority of the invention&#39;s functionality. Tray  20  is preferably formed by injection molding a compound of polypropylene. Polypropylene is preferable because it is durable, inexpensive, and can be extruded from recycled materials and be transparent to allow visibility for wheelchair mobility. All the features are included in the single molded piece so that all manufacturing complexity is contained within the one time purchase of the die. The tray, in one embodiment, is 18×12×1 inches in size, making it large enough to hold a meal, support a laptop computer, or provide space for writing or drawing. All corners are rounded to prevent any sharp edges from injuring the user. 
     Tray  20  can also contain convenient features, such as cup holders and the like. Additionally, tray  20  is molded with a 0.25 inch lip around the perimeter so that any liquids that are inadvertently spilled onto the surface will be contained within the perimeter of the tray rather than running off onto the vehicle or user. This symmetry provides support for flat objects placed on the tray (such as a laptop computer). In addition, power outlets provide power supply to the user from the existing wheelchair battery. 
     The main working area of the tray is a flat surface that can be used for holding food, for writing or drawing, or for support of a laptop computer. The surface is slightly tilted toward the front of the tray so that any writing utensils placed on the tray will roll to the front. At the very front of the tray is a groove to be used for the storage of pens or pencils. The center of the groove contains a clip to tightly secure a standard sized pen or pencil. The utensil simply needs to be snapped into the clip for storage. Once snapped into place, the utensil is snugly secured in place. 
     In a preferred embodiment, as depicted in  FIG. 7 , the stowable tray includes housing  100  having pivoting armrest top  110 . Housing  100  and pivoting armrest  110  collectively form a hollow rectangular structure when pivoting armrest  110  is in a closed position. Because housing  100  is positioned directly below armrest  110 , it can be positioned laterally on a wheelchair underneath the arms of a user, which saves space. 
     As depicted in  FIG. 8 , pivoting armrest  110  is rotated into the open position thereby allowing support arm  300  and tray  200  to be removed from housing  100 . Support arm  300  is pivotally and hingedly connected to housing  100  by a horizontal pivot and a vertical hinge. A universal joint may also be used. In the stowed position, as depicted in  FIGS. 7 and 8 , support arm  300  is in a horizontal repose position within housing  100 . 
     Support arm  300  rotates within a vertical plane from the stowed horizontal position to a second unstowed position outside of housing  100 , as depicted in  FIGS. 8 and 9 . In order to rotate support arm  300  in a vertical plane, pivoting armrest top  110  is in the open position. 
     As depicted in  FIGS. 9 and 10 , tray  200  is slideably and hingedly connected to support arm  300 . Like support arm  300 , tray  200  rotates from a first stowed position within housing  100  to a second unstowed position outside of housing  100 . Because tray  200  is slideably connected to support arm  300 , a user can extend and retract tray  200  along the end points of support arm  300 . Similarly, because tray  200  is hingedly connected to support arm  300 , a user can open and close tray  200  between a vertical and horizontal position, as depicted in  FIGS. 10 and 11 . 
     Once out of housing  100  and in the unstowed position, rotating support arm  300  and tray  200  are free to pivot in a horizontal plane, as shown in  FIG. 12 . 
     Still referring to  FIG. 12 , tray  200  includes inner portion  220  that is hingedly connected to outer portion  210  and is adapted to be tilted upward. Bracket  230  has a first end that slides within slot  240  and a second end attached to inner portion  220  and is used to secure the inner portion of the tray in the upright tilted position. 
     An extension tray (not shown) may additionally be hingedly connected to tray  200 . The extension tray has a first closed position in overlying relation to tray  200 . If a user needs additional surface space, the tray extension is extended to an open position whereby the extension tray is rotated about its hinge 180 degrees so that it abuts and is coplanar with tray  200 . 
     Referring to  FIG. 9 , an actuator may be incorporated to mechanically move tray  200  from the stowed position within housing  100  to the unstowed position outside of housing  100 . The actuator depicted in  FIG. 9  is a belt-pulley system driven by electric motor  310 . The invention, however, is not limited to this type of actuator, and a variety of other actuators known in the art may be used without departing from the scope of the invention. 
     As collectively shown in  FIGS. 7-12 , to make use of the tray, a user simply pivots the armrest to the open position and rotates the support arm and tray assembly into the horizontal unstowed position. Once in the horizontal plane, the user can adjust the location of the tray by either rotating the support arm in a horizontal plane or sliding the tray along the support arm in a horizontal plane. The user may then tilt the inner portion of the tray up and secure it in place. 
     It will be seen that the advantages set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall there between. Now that the invention has been described.