Device convertible into a chair, table, bed or stool
BACKGROUND OF THE INVENTION 
     a. Field of the Invention 
     The present invention relates generally weight supporting devices, and more particularly to such devices which are convertible into a variety of different positions. 
     b. Description of the Prior Art 
     Convertible weight supporting devices capable of supporting a person are well-known. These devices include sofa beds and lounge chairs. Usually, however, the mechanisms which these devices rely upon for convertibility weaken the structure, so that the device is not capable of rugged use, for example, in a service station or garage which repairs automobiles, motorcycles and/or trucks. 
     Service stations and garages require flatbeds, chairs with back support, tables, stools and storage means for tools. Generally, flatbeds, tables, chairs and stools have been provided separately. Tools and discarded parts have been placed on the floor, where they could be lost, damaged, or present a hazard to persons in the work area. 
     Also, a variety of power tools may be used in a garage, and the resulting number of extension cords on the floor creates a hazard and reduces mobility. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a device which can reduce or eliminate the above-noted drawbacks of the prior art. 
     It is another object of the present invention to provide a rugged device, usable in a service station garage, which can be converted from a chair shape into a stool, table and flatbed. 
     It is a further object of the present invention to provide a device which can be adapted to provide a variable amount of storage space. 
     These and other objects are achieved by the present invention. A top frame, with telescoping legs, or a telescoping plate, may be detachably stacked upon a second frame. The top frame has a seat plate attached within. A seat can be supported by and within the first frame. When the telescoping plate or legs are extended forward they provide a base for the seat, so that the device can be converted into a flatbed or a table. The back of the first frame also includes means for removably receiving a backrest in either a vertical or horizontal orientation. If desired, a third frame may be detachably stacked between the first and second frames. Further, the second and third frames may include storage means therein, and the second frame and/or third frame can include a wire mesh-bottomed tray extending outside thereof for receiving wet and/or oily tools and parts. Additionally, each frame unit may include wiring and one or more electrical outlets, so that electric tools may be plugged into the device, increasing the mobility thereof. Preferably, the second frame has rolling means, such as wheels or rollers, attached to its underside, so that the chair may be rolled to a convenient location. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     The present invention will be better understood by reference to the Figures described below, wherein like numbers refer to like structures: 
     FIG. 1 is a plan view of the chair form of a preferred embodiment according to the present invention. 
     FIG. 2 is a top view of the bottom frame of the present invention. 
     FIG. 3 is a partially exploded angled top view of the bottom frame, with attached tool tray and the drawer that fits in the frame. 
     FIG. 4 is a cross-sectional view taken along line 4--4 in FIG. 2. 
     FIG. 5 is a partially exploded angled top view of the middle frame of the invention and the drawer that fits therein. 
     FIGS. 6 and 7 illustrate the means for removably joining frames to each other, using the attachment of the middle frame to the base frame as an example, and is viewed from the bottom side along the plane where the two frames intersect. 
     FIGS. 8a and 8b show the structure of the top frame of the present invention, as viewed from the top at an angle, with the seat plate removed. 
     FIG. 9 illustrates the structure of the side members of the top frame. 
     FIG. 10 is a plan view of the seat and top frame of the present invention. 
     FIG. 11 is a cross-sectional view taken along line 11--11 of FIG. 10. 
     FIG. 12 is a cross-sectional view taken along line 12--12 of FIG. 11. 
     FIG. 13 is a plan view of the seat, taken from the bottom of the seat, with the headrest attached. 
     FIG. 14 is a plan view of the backrest of the present invention. 
     FIG. 14a is a plan view of the cushion of the backrest shown in FIG. 14. 
     FIG. 15 shows the present invention, in the chair position, with the frame removed. 
     FIG. 16 shows the present invention, in the flatbed position, with the frame removed. 
     FIG. 17 shows the present invention, in the table position, with the middle frame in place. 
     FIG. 18 is a plan view of a top frame, with the seat plate removed, of another embodiment according to the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 illustrates a preferred embodiment of the present invention, 10, in its fully assembled upright chair position. A bottom frame 12 includes opposing side members 14 (only one of which is visible in FIG. 1), front member 16, and opposing back member 18 (FIG. 2). The front 16, back 18, and side 14 members join vertical legs 20 at the corners of frame 12. Each front 16 and back 18 member is made of two bars 22, 22&#39; and 24, 24&#39;, the upper bars 24, 24&#39; having drawer guides 26 attached on the inside surfaces thereof (FIG. 2). The drawer guides 26 are preferably attached to the inside surfaces of legs 20 as well. As shown in FIG. 3, retainer clips 28 are positioned on top of upper bar 24 of front member 16 and are L-shaped pieces. A pin 30 extends upward from upper bar 24&#39; of back member 18. Four rollers 32 are attached to the bottom of frame 12. Tray 34, having a wire mesh bottom for holding tools, is attached to lower back bar 22&#39;. Tray 34 is supported by roller 32&#39; attached to the bottom thereof. 
     As best shown in FIG. 3, drawer 36 can slide into the sides of frame 12, above side members 14. Guide members 38 on drawer 36 are slidably received in drawer guides 26 in the manner illustrated in FIG. 4. 
     As best shown in FIG. 5, frame 40 has front member 42, back member 44, and side members 46. Front and back members 42 and 44, include, respectively, upper bars 48, 48&#39;, lower members 50, 50&#39; and side panels 54, 54&#39;. Vertical legs 56 are provided at the corners formed by the intersection of the front, back and side members. Drawer guides 58 extend along the inside surfaces of side panels 54, 54&#39; and vertical legs 56 and are of similar construction to drawer guides 26. Drawer 60, having guide members 62 attached to the sides thereof, slides into either side of frame 40. Guide members 62 and drawer guides 58 cooperate with each other in a manner analogous to that illustrated in FIG. 4 for guide members 38 and drawer guides 26. 
     Upper bar 48 has two retainer clips 64 analogous in position, structure and function to retainer clips 28. Upper bar 48&#39; has a pin 66 extending upwardly therefrom analogous in position, structure and function to that of pin 30. 
     Side members 46 each have lower bars 47 and upper bars 49. The top surface of upper bars 49 have rubber pads 49a attached thereto. 
     As shown in FIG. 6, lower bar 50 has, on its bottom surface, openings 68 positioned and adapted to receive the overhanging edges 28a of retainer clips 28 in the manner shown in dash dot form in FIG. 6. The illustrated positioning of overhanging edges 28a in openings 68 can be accomplished by positioning frame 40 with front member 42 tilted downward over and slightly forward of front member 16, with overhanging edges 28a laterally aligned with openings 68. Frame 40 is then moved rearward so that overhanging edges 28a fit into openings 68. Then, back member 44 of frame 40 is rotated downward so that pin 30 is received in opening 70 on the bottom surface of lower back member 50&#39; (FIG. 7). The above procedure can be reversed to remove frame 40 from frame 12. 
     As shown in FIG. 8a, frame 80 has front and rear members 82, 84, respectively, and side members 86. Each side member 86 houses a telescoping leg 88 shown in fully extended position in FIG. 8a and in retracted position in FIG. 8b. 
     As best shown in FIG. 9, side members 86 are hollow and define boxes 90 at the corners where front and rear members, 82, 84, respectively, intersect side members 86. Boxes 90 have two adjoining cut-out faces, 90a and 90b, which, when assembled within frame 80 provide vertical and horizontal openings, 90c and 90d, respectively. The face of box 90 opposing faces 90a and 90b also has cut-out 91a and hollow 91b. When extended, telescoping legs 88 extend forward through cut-out 90d and hollow 91b at the front end of frame 80. 
     As shown in FIGS. 10 and 11, a seat plate 92 is fixed by suitable means (rivets, welding, etc.) within frame 80 to define a flat upper surface therein. A seat 94, which includes a cushion 96 fixed to a cushion plate 98 made of steel or other strong and rigid material, is removably supported by frame 80 (including seat plate 92). The seat 94 can be supported on frame 80 by friction and gravity, without other means for attachment (as shown in FIG. 10) or can be fixed by hinge 100 to a forward face 82a of front member 82 (as shown in FIG. 12). Seat 94 can be rotated about the center of hinge 100 as indicated by the arrows to convert seat 94 from the folded form (solid lines) to the unfolded form (dotted lines). In its unfolded position, seat 94 is supported upon telescoping legs 88, the cushion plate 98 being on the top and cushion 96 facing and resting upon telescoping legs 88. 
     If desired, cushioned piece 102 can be removably attached by button or snap to the back end of cushion plate 98 with strap 104 (FIG. 13) and used as a back support when seat 94 is folded (solid lines) or as a head rest when seat 94 is unfolded (dotted lines). Strap 104 is made of a flexible material and is sewn or otherwise attached to back side 102a of piece 102. When piece 102 is used as a headrest, as shown in FIG. 12, strap 104 can be tucked between cushion plate 98 and surface 102a, while surface 102b faces up. 
     Front and back members 82 and 84, respectively, have bottommost surfaces essentially identical to those of front members 46, 42 and back members 18, 44 (see FIGS. 6 and 7) so that frames 40 and 80 are interchangeable and removably stackable upon frame 12 and so that frame 80 can also be removably stacked upon frame 40. 
     As shown in FIG. 14, backrest 106 includes backrest frame 108, with legs 108&#39; being slidably insertable with vertical openings 90c or horizontal openings 90d at the back end of frame 80. Backrest pad 110 is fixed within backrest frame 108. As illustrated in FIG. 14a, backrest pad 110 has a structure analogous to that of seat 94, with cushion 112 supported by cushion plate 114. 
     In order to minimize the weight of the device 10, the frame member, including vertical legs 20, should preferably, to the extent practical, be hollow. In addition to minimizing weight, the use of hollow frame members permits the chair to be internally wired, so that one or more electrical outlets 116 may be provided on any frame thereof (FIG. 14). Each frame member may be connected to a power source (not shown) via an electrical cord 118 (FIG. 14) also attached, removably or permanently, to that frame or a frame electrically connected thereto. If desired, each frame can be internally wired and have electrical contacts (not shown) permitting electrical communication between each stacked frame. For example, the pins provided on the frame back members could also serve as properly insulated electrical contacts between frames. In that embodiment, the power cord is preferably attached to the bottom frame. The provision of outlets 116 and cord 118 permit a variety of power tools (not shown) to be connected to the power source through the device 10, thus reducing clutter. 
     In FIG. 1, the device 10 is in the full chair position. Telescoping legs 88 are retracted, frame 40 is stacked atop frame 12, and frame 80 is stacked atop frame 40. The seat 94 is folded and piece 102 is vertically oriented. Frame 108, with cushion 110, of backrest 106, is inserted within vertical openings 90d in the back of frame 80. 
     In FIG. 15, device 10 is in a position similar to that shown in FIG. 14, except that frame 40 has been removed and frame 80 is stacked directly atop frame 12. 
     In FIG. 16, device 10 is in a flat &#34;bed&#34; position. To achieve the position shown in FIG. 16, a person can start with the arrangement shown in FIGS. 14 or 15. If starting with the arrangement of FIG. 14, frame 40 must be removed and frame 80 stacked directly atop frame 12. Telescoping legs 88 are extended and seat 94 is unfolded to be supported by base 88&#39; formed by the extended telescoping legs. Backrest 108 is removed from vertical openings 90c in the back of frame 80 and inserted into horizontal openings 90d. Piece 102 is moved to a horizontal position. 
     In FIG. 17, the device 10 is in a table position. This position is essentially the same as that shown in FIG. 16, but in FIG. 17, frame 40 has been stacked between frames 12 and 80. 
     If the backrest and piece 102 of the chair shown in FIG. 1 or FIG. 15 is removed, the device 10 becomes a stool. 
     In an alternative embodiment, telescoping legs 88 defining the base can be augmented or replaced by including, in frame 80, telescoping plate 181 which retracts into and can be extended forward of the upper frame. As shown in FIG. 18 telescoping plate 181 can slide, over or under the seat plate, through a slot 183 in front member 182 of frame 180 replacing frame 80. Frame 180 is constructed virtually identically to frame 80 of the prior embodiment, with the exception of the provision of slot 183 in front member 182 and guide rail means 185 on the inside surfaces of side members 186. Rear member 184 may have the same structure as corresponding rear member 84 of frame 80. Telescoping legs 188 are attached to each side of telescoping plate 181 for extension and retraction therewith into frame 180, telescoping legs sliding within hollow side members 186. When a telescoping plate is used, the seat can be a cushion without a cushion plate, since, in each position, the bottom of the cushion will be supported by the telescoping plate 181. 
     Further details regarding construction of the present invention, including exact dimensions for each part of an exempletive embodiment of the present invention are described in the Disclosure Documents filed in the United States Patent and Trademark Office on Sept. 16th and Oct. 12, 1988 (numbers not yet received), both of which are incorporated herein by reference. 
     Also, the present invention may be used in a variety of circumstances, including hospitals, doctors&#39; offices, grocery stores, plumbing shops, nursery farms, sewing plants, furniture assembly plants, race tracks, detail shops, ship yards, machine shops, boat and trailer shops, rehabilitation centers, child&#39;s nursery, casinos, refrigeration plants, commercial transit (train, bus or plane), hunting and other sports, devices for use by handicapped (especially children), as well as other domestic and commercial uses. 
     Obviously, many other variations of the present invention can be constructed without departing from the present invention as reflected in the scope of the appended claims.