Patent Document

FIELD OF THE INVENTION 
     The present invention relates to systems and methods for forming work or support surfaces and, more specifically, to such systems and methods that allow an angle of the work surface to be adjusted. 
     BACKGROUND OF THE INVENTION 
     In many situations, the need exists for a table or other structure for creating a support surface at a desired height and orientation. For example, a table that forms a writing surface should be at a height between the waist and the chest and should be substantially horizontal. However, it may be desirable for a stand for a computer monitor to form a support surface that is angle with respect to horizontal. 
     In many situations, then, tables are made adjustable to allow an angle of a work surface to be adjusted in relation to a reference surface. For example, a draftsman&#39;s table comprises a leg structure that defines a reference plane and a work surface that is adjustable relative to the reference plane. 
     The present invention relates to table structures that allow adjustment of a working surface relative to a reference plane. The present invention has particular significance in the context of forming a work surface over a steering wheel, and that application will be described in detail herein. However, the present invention has broader application to other environments requiring an adjustable table system. Accordingly, the scope of the present invention is defined by the claims appended hereto rather than the following detailed description. 
     In motor coaches, space is at a premium. In addition, the driver and passenger seats of motor coaches are designed for prolonged sitting and thus are very comfortable. Accordingly, it is common to use the cab of a motor coach as an “office” when the motor coach is parked. 
     Commonly, a temporary work surface is provided for use with the seating surfaces formed by the driver and passenger seats. This temporary work surface is formed by a rigid member or panel that defines the work surface and is attached, using a variety of means, to the steering wheel of the motor coach. Such temporary work surfaces provide a stable, flat surface that is supported at generally the right height to form a desk or writing surface. Because the steering wheel is often not completely horizontal, the rigid panel is often pivotably connected at one end to the steering wheel, and braces are provided to lift the other end such that the working surface is substantially horizontal. 
     The prior art temporary work surfaces of which the Applicant is aware are generally complex, relatively expensive mechanical devices that are dedicated solely for use as a temporary work surface supported by a steering wheel. 
     The need thus exists for improved, cost effective systems and methods of forming an adjustable work surface that may be used, as one example, for form a desk surface in the cab of a motor coach. 
     PRIOR ART 
     The following patents were uncovered as part of a professional patentability search conducted on behalf of the Applicant. 
     U.S. Pat. No. 6,038,983 to LendI discloses a steering column table having a lower part that is attached to a vehicle steering wheel and an lid pivotably connected to the lower part. A support device is pivotably connected to the lid between the lid and the lower part. The lid is rotated through a desired angle until it is generally level, and then the support device is rotated down until it engages a slot in the lower part. With the support device engaged in the slot, the lid is held fairly close to the desired angle. 
     U.S. Pat. No. 6,036,158 to Raasch discloses a steering wheel mounted tray defining a slot through which a portion of a steering wheel extends. The slot is shorter than the diameter of the steering wheel, so the steering wheel engages and supports the tray. The angle of the tray relative to the steering wheel does not appear to be adjustable, and this device would not work if the steering wheel is substantially horizontal. 
     U.S. Pat. No. 4,890,559 to Martin discloses a device similar to the LendI device in which a base is attached to the steering wheel column. A top panel is rotatably attached to the base. Leg members arranged on either side of the base member are rotatably attached to the top panel. The leg members are fixed to the base when the top panel is at a desired angle. 
     U.S. Pat. No. 4,749,161 to Falcone discloses a steering wheel table that folds flat when stored. During use, two main panels fold out and hook onto the steering wheel to form a table surface slanted at the same angle as the steering wheel. Two side panels fold out from one of the main panels to create a small generally horizontal surface. The angles of the main panels and side panel are not adjustable relative to the steering wheel. 
     U.S. Pat. No. 2,866,381 to Alldredge discloses a stereographic map reading apparatus that has a table for supporting the map. The table engages a steering wheel to form a pivoting connection; a brace extends from the edge of the table distal from the steering wheel to support the table in a generally horizontal position. 
     U.S. Pat. No. 2,749,655 to Ashton discloses a portable desk designed to be attached to a steering wheel. The Ashton device folds for storage. When opened, hooks are exposed which engage the steering wheel. This device does not appear to be adjustable. 
     U.S. Pat. No. 2,487,536 to Fiscus discloses a desk attachment for a steering wheel comprising a flat member and two bracket members. The bracket members have a hook on an upper end and are triangular such that the bracket members space the lower end of the flat member from the steering wheel. The bracket members make the angle of the flat member closer to horizontal, but the flat member is far from horizontal, and the angle is not adjustable. 
     All of the devices disclosed in these patents are relatively complex, expensive devices, and none of these devices are, practically speaking, continuously adjustable. 
     SUMMARY OF THE INVENTION 
     An adjustable table system comprising first and second offset members, an attachment system, a support assembly, and a work surface assembly. The offset members each comprise offset edges defining a offset planes, engaging surfaces defining reference planes, and spacing walls extending between the offset edges and the engaging surfaces. The spacing walls are sized and dimensioned to create offset angles between the offset planes. The attachment system attaches the offset members together such that the offset members are rotatable relative to each other about an offset axis. The support assembly engages one of the offset members to support the offset member at a desired location. The work surface assembly engages the other offset edge to form a work surface at the desired location. Rotation of the offset members relative to each other about the offset axis alters an angle between the offset planes and thus an angle of the work surface with respect to horizontal. 
    
    
     DESCRIPTION OF THE DRAWING 
     FIG. 1 is view depicting a table assembly of the present invention; 
     FIG. 2 is view of the table and its angle adjusting system; 
     FIG. 3 is a side elevation view of the table showing a different angle of adjustment; 
     FIG. 4 is a section view of the table assembly of FIG. 1; 
     FIG. 5 is a section view of the table assembly of FIG. 1 taken along lines  5 — 5  in FIG. 4; 
     FIG. 6 is a view of the mounting groove of the table assembly; 
     FIG. 7 is another view of the mounting groove of the table assembly; 
     FIG. 8 is a view of the table member; 
     FIG. 9 is a view of the first offset member; 
     FIGS. 10A,  10 B,  10 C, are views showing the grooves of the table member; and 
     FIG. 11 is view showing the mounting system of the table assembly. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawing, depicted at  20  therein is a table system constructed in accordance with, and embodying, the principles of the present invention. The exemplary table system  20  is adapted to be mounted on to a steering wheel  22  supported by a steering column  24 . The table system  20  is particularly suited for use with a steering wheel as described herein, but the present invention may, as will be described in further detail below, have application to other environments. The scope of the present invention should thus be determined by the claims appended hereto and not the following detailed description. 
     The exemplary table system  20  comprises a reference surface  30  and a working surface  32 . The reference surface  30  engages the steering wheel  22 . The working surface  32  forms a platform on which books, papers, computers, and the like may be supported while working. 
     The table system  20  further comprises an angle adjusting system  34  that, as shown by a comparison of FIGS. 1 and 2, allows a table angle a between planes A and B defined by the reference and working surfaces  30  and  32  to be adjusted. 
     With the foregoing general understanding of the present invention in mind, the details of the exemplary table system  20  will now be described. As perhaps best shown in FIG. 4, the reference surface  30  is defined by a first table member  40 , while the working surface  32  is defined by a second table member  42 . 
     The exemplary angle adjusting system  34  comprises a first offset member  50 , a second offset member  52 , and axle means  54 . The axle means  54  connects the first and second offset members  50  and  52  together such that the offset members  50  and  52  rotate relative to each other about an offset axis C depicted in FIGS. 2-4. FIG. 4 also depicts a mounting system  60  used to attach the exemplary system  20  to the steering wheel  22 . 
     In the exemplary table system  20 , the first table member  40  is identical to the second table member  42  and the first offset member  50  is identical to the second offset member  52 . It is not necessary that these members  40 ,  42 , and  50 ,  52  be identical to each other, but doing so decreases manufacturing costs and results in aesthetically pleasing design. 
     In addition, in some forms of the present invention, the table members may be integrally formed with its associated offset member. If the table system  20  is to be manufactured using conventional injection molding techniques, the table members are preferably manufactured separate from the offset members and joined during use. However, if other manufacturing techniques are used, such as rotational molding, it may be cost effective to integrally form the table members with the offset members. 
     Because the exemplary table members  40 ,  42  are identical and the exemplary offset members  50  and  52  are identical, only the first table member  40  and the first offset member  50  will be described in detail herein with an understanding that this description applies to the second table member  42  and the second offset member  52 . 
     Referring again to FIG. 4, the first table member comprises a central portion  70  and a perimeter portion  72 . A maximum thickness T 1  of the perimeter portion  72  is substantially greater than a minimum thickness T 2  of the central portion  70 . For some materials and manufacturing techniques, such as milled wood, the thickened central portion  70  will be a solid thickened layer extending in an annular ring around the table member  40 . With other materials and manufacturing techniques, such as injection molded plastic, the thickened portion T 1  would preferably be made by discreet flanges radially extending from the central portion  70 . 
     Referring now to FIG. 8, it can be seen that the exemplary table member  40  is thickened around its entire perimeter portion  72 . The table member  40  thus defines an inner surface  74  that is not planar. In contrast, the reference surface  30  defined by the table member  40  is substantially planar so that it may be used as a writing or desk surface as desired. 
     FIG. 8 also shows that inner and outer annular grooves  80  and  82  are formed on the inner surface  74 . These grooves are depicted in more detail in the enlarged drawing of FIG.  10 A. The purpose of these grooves  80  and  82  is to allow a hole to be formed in the table member if desired. In particular, FIG. 10A shows that these grooves  80  and  82  create a substantially reduced thickness T 3  in the central portion  70  of the table member  40 . The material from which the table member  40  is manufactured is strong enough to bear the loads of normal use as a writing table or desk without breaking at the reduced thickness portions defined by the grooves  80  and  82 . However, if a hole if desired in the table member  40 , a disc or ring may be punched out of the central portion  70  to form such a hole. 
     In particular, as shown in FIG. 10B, punching or scoring the table member  40  along the inner groove  80  can establish a first hole  84  having a diameter of approximately D 1  in the table member  40 . And as shown in FIG. 10C, punching or scoring along the outer groove  82  establishes a hole having a diameter of approximately D 2 . As shown, the diameter D 2  of the second hole  86  will be greater than the diameter D 1  of the first hole  84 . 
     The holes  84  or  86  are concentric with each other and with the overall dimensions of the table member  40  in the exemplary table system  20 . However, grooves may be formed at other locations in the table member  40  to allow the user to form one or more holes at different locations as desired. 
     The purpose of these holes is to allow the user to extend power cords, computer cables, and the like through the table system  20 . This would allow the user to maintain a more organized workspace on the working surface  32  formed by the table system  20 . 
     Referring now to FIGS. 5-6, it can be seen that a mounting groove  90  is formed in the inner surface  74  of the exemplary table member  40 . The exemplary mounting groove  90  is a continuous groove that extends around the entire perimeter portion  72 , but a similar affect may be obtained by forming discrete grooves or relief cuts in each of a plurality of flanges formed on the underside of a table member of a different configuration. The purpose of the mounting groove  90  is to allow the table member  40  to be detachably attached to the first offset member  50 , as will be described in further detail below. 
     As briefly described above, the first and second offset members are identical, so only the first offset member  50  will be described herein in detail. As shown in FIG. 9, the first offset member  50  comprises an engaging wall  120 , an offset edge  122 , and a spacing wall  124 . The engaging wall  120  defines an engaging surface  130  that, in the exemplary table system  20 , is substantially planar. The offset edge  122  defines an offset plane D that extends at an angle β with respect to an engaging plane E defined by the engaging surface  130 . 
     The spacing wall  124  extends from the offset edge  122  to a perimeter edge  132  defined by the engaging wall  120 . 
     In the exemplary offset member  50 , the engaging wall  120  and thus the perimeter edge  132  thereof, is circular and has a diameter D 3 . The exemplary offset edge  122  is also circular and has a diameter D 4 . 
     The spacing wall  124  is defined by the shortest lines extending between the offset edge  122  and the perimeter edge  132 . Because these edges  122  and  132  are circular, the exemplary spacing wall  124  is not a true cylinder. The geometry of the spacing wall  124  is not critical to any given implementation of the present invention. 
     FIG. 9 also shows that an attachment hole  134  is formed in the engaging wall  120 . The attachment hole defines the offset access C described above. As will be described in further detail below, the attachment hole  134  forms part of the axle means  54  described above. 
     The exemplary angle adjusting system  34  is formed by arranging the first and second offset members  50  and  52  such that their respective engaging surfaces  130  are in contact and the perimeter edges  132  are aligned. The attachment holes  134  of the offset members  50  and  52  will also be aligned. As the first and second offset members  50  and  52  rotate relative to each other while maintaining alignment of the perimeter edges  132 , the angle between the offset planes D will change. 
     In practice, the reference plane A is substantially parallel to one of the offset planes D, while the working plane B is substantially parallel to the other of the offset planes D. Accordingly, the angle between the offset planes D when the angle adjusting system  34  is assembled will equal the table angle a between the reference and working planes A and B. In this respect, it should be noted that the maximum of the table angle α between the reference and working planes A and B will be equal to twice the angle β, between the offset plane D and engaging plane E. The table angle α can also be decreased to zero in some configurations. 
     Referring again back to FIG. 4, the axle means  54  will now be described in further detail. In addition to the attachment holes  134  described above, the axle means  54  comprises an axle member  140 . The exemplary axle member  140  is an annular piece defining a through hole  142  and an annular groove  144 . The annular groove  144  is defined by an interior wall  150  and first and second opposing walls  152  and  154 . Because the groove  144  is annular, the interior wall  150  is in the shape of a ring, and its diameter is slightly less than that of the attachment hole  134 . In addition, the distance between the opposing walls  152  and  154  is just slightly greater than twice the thickness of the engaging walls  120 . 
     In use, the axle member  140  is arranged such that the portions of the engaging walls  120  adjacent to the attachment holes  134  are received in the attachment groove  144 . This allows the offset members  50  and  52  to rotate relative to each other but maintains the alignment of the perimeter edges  132 . 
     The axle means  54  may be formed by other physical structures. For example, a flange or ridge may be integrally formed with and extend from the offset members and through the associated attachment hole of the other offset member. 
     Referring now to FIGS. 6 and 7, the method of attaching the first and second table members  40  and  42  to the first and second offset members  50  and  52  will now be described in further detail. As shown in FIGS. 6 and 7, the offset edge  122  is received in the mounting groove  90 . In addition, the grooves  90  are slightly out of round so that rotation as shown by arrow F in FIG. 7 of the first table member  40  relative to the first offset member  50  causes the mounting grooves  90  to bind against the spacing walls  124  to form a friction fit that prevents removal of the table member  40  from the offset member  50 . The table member  40  may be detached from the offset member  50  by simply rotating the table member in a direction opposite the direction shown by arrow F until the mounting grooves  90  align with the spacing walls  120  as shown in FIG.  6 . 
     Referring now to FIGS. 4 and 11, the mounting system  60  will now be described in further detail. The mounting system  60  comprises a plurality of mounting blocks  160  that are attached to the reference surface  30  of the first table member  40 . The exemplary mounting blocks  160  comprise a straight side  162  and a contoured side  164 . At least two of these mounting blocks  160  are affixed to the reference surface  30  such that a distance between the straight side  162  of one of the blocks and the contoured side  164  of an opposing block is approximately the same as the diameter of the steering wheel  22 . 
     In addition, during use, one of the mounting blocks  160  will engage an upper portion  22   a  of the steering wheel  22  and another of the blocks  160  will engage a lower portion  22 b of the steering wheel  22 . The lowermost block  160  is arranged with its contoured side  164  facing the central portion  70  of the table member  40 , while the uppermost of these blocks  160  will be arranged with its contoured surface  164  facing away from the central portion  70 . The contoured side  164  of the uppermost mounting block  160  engages the steering wheel upper portion  22   a , while the straight side  162  of the lowermost block  160  engages the wheel lower portion  22   b.    
     This arrangement of mounting blocks  160  allows the contoured surface  164  to be extended partly around a portion of the steering wheel  22 , at which point the table system  20  is rotated such that the straight side  162  of the lowermost block engages and rests on a lower portion of the steering wheel  22 . 
     Accordingly, downward loads on the table assembly are transferred to the steering wheel  22  through the first table member  40  and the lowermost mounting block  160 . The contoured side  164  of the uppermost block  160  will prevent the table system  20  from rotating out of the steering wheel  22  about an axis defined by the lower portion of the steering wheel  22 . 
     During normal use, the mounting blocks  160  will stably connect the table system  20  to the steering wheel  22 . However, the table system  22  may be easily removed from the steering wheel  22  simply by lifting the table system  20  such that it pivots about the upper portion  22   a  of the steering wheel  22  until the straight surface  162  of the lowermost block  160  disengages from the lower portion  22   b  of the steering wheel  22 . FIG. 11 illustrates that, although at least two mounting blocks  160  are used by the mounting system  60 , this system  60  is optimized when more than two blocks  160  are used. 
     In the exemplary mounting system  60 , six identical mounting blocks  160  are used. In addition, as indicated by the broken lines illustrating the contoured sides  164 , the contoured sides  164  of the lowermost blocks  160  face radially inwardly while the contoured sides  164  of the uppermost blocks face radially outwardly. 
     From the foregoing, it should be apparent that the present invention may be embodied in many different combinations and sub-combinations of the elements and steps described above. For example, the exemplary offset edges  122  and perimeter edges  132  are both circular and have the same diameter. These offset and perimeter edges need not be completely circular and need not have the same diameter in a less optimized implementation of the present invention. 
     The scope of the present invention should thus be determined by the following claims and not the foregoing detailed description.

Technology Category: b