Abstract:
The desk extension is quickly and conveniently attached and removed from the edge of a desk or table to provide additional surface area for the user. The desk extension has two parallel panels or levels when deployed to maximize the available area. The two panels are held parallel to one another when deployed, and one panel folds into a recess in the bottom of the other panel for storage when not in use. A clamp mechanism includes two folding clamps that are pivoted beneath the upper plate of the clamp assembly for compact storage when not in use. The clamp mechanism is pivotally attached to the edges of the lower panel to position the two panels horizontally when the extension is attached to a sloped surface, or to position the two panels at an oblique angle, if desired.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to furniture and furnishings, and particularly to a folding desk extension for removable attachment to the edge of a desk, table, or the like. 
     2. Description of the Related Art 
     The typical academic classroom desk is relatively small and provides barely sufficient room for an open book and a standard sheet of writing paper. The typically small area provided by the average academic desk surface may be due to various factors, such as the need to economize on space to maximize the number of desks and students in a classroom, the desire of school officials to economize by minimizing the size and corresponding cost of classroom desks, and other factors. In any event, the surface area of the desk is often minimal for the needs of the student. 
     As schools and students have increasingly accepted the use of personal computers, much of the limited desktop space available is often taken up by a laptop computer and keyboard, leaving little or no space for books, note paper, and other essential tools and equipment. In many cases additional room is required for manipulating a computer mouse when the computer is not equipped with a touch screen or track ball. The typical academic classroom student desk severely limits the activities of the student occupying the desk. The distractions of maneuvering and manipulating different articles to provide room for the specific article needed at the immediate time (book, note paper, computer, etc.) may draw attention away from the learning experience. 
     Thus, a desk extension solving the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     The desk extension includes two separate rigid panels or levels that are connected to one another by rigid parallel arms. One of the panels nests within the bottom of the other panel when the extension is folded for storage. The two panels are held parallel to one another with one above the other when deployed for use. The upper panel may include various compartments or recesses adapted for use as a cup holder, pen and pencil grooves or trays, and/or other purposes. 
     The lower panel includes a desk clamp mechanism extending therefrom. The desk clamp mechanism is pivotally attached to opposite edges of the lower panel. The angle between the lower panel and the desk clamp is adjustable and lockable to secure the two panels at any desired angle when the device is secured to a sloped desk or other surface. The desk clamp mechanism includes a pair of folding clamps that can be pivoted to lie flat beneath the upper surface of the desk clamp mechanism for compact storage when not in use. The clamps and clamping mechanism are configured to facilitate their rapid installation and removal to and from a desk in order to minimize the time required at the beginning and end of a classroom period. 
     The two panels of the desk extension serve to maximize the available amount of combined surface area of the desk to which the desk extension is attached and the desk extension itself, while minimizing the horizontal area required for the combination. The panels of the desk extension are preferably formed of plastic to minimize weight. The folded device is both lightweight and compact for convenient storage in a book bag or the like when not in use. 
     These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a desk extension according to the present invention as viewed from above the device, illustrating its basic features. 
         FIG. 2  is a perspective view of the desk extension of  FIG. 1  in the same configuration, but viewed from below, illustrating further features thereof. 
         FIG. 3  is a perspective view of the desk extension of  FIG. 1 , shown with the desk clamp portion of the device pivoted upward. 
         FIG. 4  is a side elevation view of the desk extension of  FIG. 1 , illustrating further details of the desk clamp mechanism. 
         FIG. 5  is a side elevation view of the desk extension of  FIG. 1 , illustrating an initial step in the process of folding the device. 
         FIG. 6  is a side elevation view of the desk extension of  FIG. 1 , illustrating a further step in the process of folding the device. 
         FIG. 7  is a side elevation view of the desk extension of  FIG. 1 , showing the desk extension in its completely folded state. 
         FIG. 8  is a perspective view of the desk extension of  FIG. 1  as seen from below, showing the desk extension in its completely folded state. 
     
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The desk extension comprises a compact means of providing additional horizontal, or substantially horizontal, surface area for a desk, table, or the like, without a corresponding increase of the total subtended area. This is due to the two separate surfaces overlying each other when the desk extension is deployed for use. It should be noted that while the device is titled “desk extension,” it may be attached to or used a variety of furniture articles or furnishings, e.g., tables, desks, drafting boards, work stations, shelves, etc. 
       FIG. 1  provides a top perspective view of the desk extension  10  in its deployed state as it would be removably attached to the edge of a desk D, the desk D being shown in broken lines. The desk extension  10  includes a base or first panel  12  having a first surface  14 , i.e., the upper surface when deployed, an opposite second or lower surface  16  (shown in  FIG. 2 ), a linkage attachment edge  18 , a clamp extension edge  20 , and mutually opposed first and second lateral edges  22   a  and  22   b  extending between the linkage attachment edge  18  and the clamp extension edge  20 . 
     A second or upper panel  24  is disposed above the base or first panel  12  when the desk extension is deployed for use as shown in  FIG. 1 . The second panel  24  includes a first surface  26 , i.e., the upper surface when deployed for use, a second surface  28  opposite the first surface (shown in  FIG. 2 ), a linkage attachment edge  30 , and a free edge  32  opposite the linkage attachment edge  30 . The first or upper surface  26  preferably includes a plurality of article holder recesses defined therein, e.g., one or more pencil or pen holder grooves  34   a , a cup holder  34   b , a mouse or other implement holder  34   c , etc. These various article holder recesses  34   a  through  34   c  may be used to temporarily hold the above-mentioned articles, and/or any other suitable articles. Both the second or upper panel  24  and the base or first panel  12  are preferably formed of plastic, but other materials may be used alternatively. 
     A linkage comprising parallel first and second arms  36   a  and  36   b  connects the two panels  12  and  24  to one another. Each arm  36   a ,  36   b  has a base panel end  38   a ,  38   b  pivotally attached to the linkage attachment edge  18  of the first or lower panel  12 , and an opposite upper or second panel end  40   a ,  40   b  pivotally attached to the linkage attachment edge  30  of the second or upper panel  24 . 
     Each of the linkage arms  36   a ,  36   b  includes a base or first panel limit stop comprising a stop or limit tab  42   a ,  42   b  (shown in  FIGS. 3 and 8 ), extending therefrom adjacent to the respective base or first panel end  38   a ,  38   b  of the arm. The tabs  42   a ,  42   b  contact the first or upper surface  14  of the first or base panel  12  when the two linkage arms  36   a ,  36   b  are cantilevered to about a 60° angle relative to the first or base panel  12  to prevent the two linkage arms  36   a ,  36   b  from rotating or pivoting to a more acute angle relative to the base panel  12 . The limiting angle, e.g., 60°, may be adjusted according to the locations of the two stop or limit tabs  42   a ,  42   b.    
     Angular limitation of the second or upper panel  24  relative to the two linkage arms  36   a ,  36   b  is provided by a second panel limit stop comprising a bar  44  that extends between the two arms  36   a ,  36   b  adjacent their second panel ends  40   a ,  40   b . The second or lower surface  28  of the second or upper panel  24  adjacent its linkage attachment edge  30  engages or rests upon the stop limit bar  44  when the second or upper panel  24  is fully deployed. The exact location or position of the stop limit bar  44  is set to stop the rotation of the second or upper panel  24  between the linkage arms  36   a ,  36   b  so that it extends parallel to the lower or first panel  12  when the desk extension  10  is fully opened or deployed, as shown in  FIGS. 1 through 4 . In other words, when the desk extension  10  is fully deployed for use, the angle between the lower or base panel  12  and the linkage arms  36   a ,  36   b  and the angle between the second or upper panel  24  and the linkage arms  36   a ,  36   b  add up to 180°. As shown in  FIG. 3 , a clearance groove or channel  46  is formed laterally across the upper or first surface  26  of the upper or second panel  24 . The stop limit bar  44  nests in the clearance groove or channel  46  when the upper or second panel  24  is rotated to lie between the two linkage arms  36   a ,  36   b  when the desk extension  10  is folded for storage, as shown in  FIGS. 7 and 8  and described further below. It will be seen in  FIGS. 1 ,  3 , and  4  that the clearance groove or channel  46  may also serve as an additional pencil or pen holder or the like when the desk extension  10  is fully deployed. 
       FIGS. 3 through 8  show a desk clamp assembly that extends from the first or base panel  12 . The desk clamp assembly serves to secure the desk extension  10  temporarily and removably to the edge of a desk D or other suitable surface or structure. The desk clamp assembly comprises parallel first and second clamp arms  48   a ,  48   b  extending from first and second clamp arm locks  50   a  and  50   b  respectively disposed along the first and second lateral edges  22   a  and  22   b  of the first or base panel  12 . The clamp arm locks  50   a ,  50   b  comprise screws or bolts about which the first panel attachment ends  52   a  and  52   b  rotate or pivot for deployment and folding. The screws or bolts may be tightened or loosened to lock the orientation of the two clamp arms  48   a ,  48   b  at a predetermined angle relative to the first or base panel  12 , or to allow them to pivot or rotate as desired. Each of the clamp arms  48   a ,  48   b  has a distal end  54   a ,  54   b , and a desk attachment plate  56  extending thereacross. The two parallel clamp arms  48   a ,  48   b  define a plane. The desk attachment plate  56  lies parallel to the plane of the clamp arms  48   a ,  48   b , as shown in the various drawing Figures. A clamp attachment plate  58  extends from the desk attachment plate  56 , normal to both the desk attachment plate  56  and the two clamp arms  48   a  and  48   b.    
     At least one clamp, and preferably two clamps pivotally extend from the clamp attachment plate  58 . Each clamp comprises an elongate bolt  60  having a base portion  62  that extends pivotally from the clamp attachment plate  58  normal thereto, and a threaded clamp portion  64  normal to the base portion  62 . Thus, each clamp bolt  60  has a substantially L-shaped configuration. An elongate clamp finger  66  is slidably disposed upon the threaded portion  64  of the clamp bolt  60  so that the elongate extension of the clamp finger  66  is disposed parallel to the plane of the desk attachment plate  56  when the threaded clamp portion  64  of the clamp bolt  60  is pivoted normal to the desk attachment plate  56 , as shown in  FIGS. 3 through 6  of the drawings. An adjustably threaded fastener  68 , e.g., a wing nut or other easily manipulated device, is disposed upon the threaded clamp portion  64  of the clamp bolt  60 . The fastener  68  may be threaded along the clamp portion  64  of the bolt  60  in order to advance the clamp finger  66  to clamp the edge of a desk D or other surface between the desk attachment plate  56  and the clamp finger  66 , or to loosen the clamp finger  66  to allow the desk extension  10  to be removed from the desk D or other surface. The pivotal attachment of the base portion  62  of the clamp bolt  60  allows the clamp assembly to be pivoted parallel to the desk attachment plate  56  for compact storage, as shown in  FIGS. 7 and 8 . 
     In order to attach the desk extension  10  to the edge of a desk D or other suitable surface, the clamp bolts  60  are pivoted so that their threaded portions  64  are substantially normal to the plane of the desk attachment plate  56 , and the device is placed upon the edge of the desk D with the desk attachment plate  56  adjacent to the upper surface of the desk D and the clamp fingers  66  below the edge of the desk D. The fasteners  68  are then tightened to clamp the edge of the desk D between the desk attachment plate  56  and the clamp fingers  66 . Removal of the desk extension  10  is accomplished by reversing the above procedure. 
       FIG. 4  provides a side elevation view of the deployed desk extension  10  ready for use.  FIGS. 5 and 6  show intermediate orientations of the two panels  12  and  24  and the linkage arms, e.g., arm  36   a , during the folding process.  FIGS. 7 and 8  illustrate the desk extension  10  in its completely folded state. (It should be noted that  FIGS. 3 and 4  show an alternative adjustment of the desk extension  10 , in which the clamp arms  48   a  and  48   b  are at an oblique angle to the plane of the base or first panel  12  in order to secure the desk extension  10  to a non-horizontal desk D, while orienting the two panels  12  and  24  substantially horizontally.) In  FIG. 4 , the two panels  12  and  24  of the desk extension  10  are fully deployed parallel to one another and spaced apart from one another, i.e., non-coplanar, by the linkage arms, e.g., arm  36   a  shown in the side elevation view of  FIG. 4 . 
     In  FIG. 5 , the linkage arms remain at their fully deployed angle relative to the first or base panel  12 , as shown by the linkage arm  36   a  in  FIG. 5 . However, the second or upper panel  24  has been rotated clockwise about its pivotal attachment to the upper or second panel ends of the linkage arms, as shown by the end  40   a  of the linkage arm  36   a  in  FIG. 5 . The rotation of the second panel  24  relative to the linkage arms subtends an angle of about 230° in  FIG. 5 , leaving about another 10° remaining to position the second panel  24  between and parallel to the two linkage arms  36   a ,  36   b . It will be seen that if the second panel  24  were rotated to lie parallel to and between the two linkage arms,  36   a ,  36   b , its rotation from its fully deployed horizontal position would be about 240° due to the approximately 60° angle between the lower or base panel  12  and the linkage arms. 
     In  FIG. 6 , the second panel  24  retains its rotation of about 230° relative to the two linkage arms  36   a ,  36   b , the first linkage arm  36   a  being shown in  FIG. 6 . However, the linkage arms  36   a ,  36   b  have also been rotated about 260° clockwise relative to the first or base panel  12 . About another 60° degrees remain in order to position the linkage arms  36   a ,  36   b  parallel to the base panel  12 . 
       FIGS. 7 and 8  illustrate the desk extension  10  in its completely folded state. In  FIG. 7 , the second or upper panel  24  has been rotated to lie between the two linkage arms, i.e., a clockwise angular rotation of substantially 240° from its deployed state cantilevered from the two extension arms  36   a ,  36   b  as shown in  FIGS. 1 through 4 . In addition, the two linkage arms  36   a ,  36   b  have been rotated to lie parallel to the first or base panel  12 , i.e., a clockwise rotation of substantially 300° from their fully deployed state, as shown in  FIGS. 1 through 4 . It will be seen that the second or upper panel  24  rotates through a total are of substantially 540° degrees, or one and a half revolutions, from its deployed state cantilevered from the two linkage arms  36   a ,  36   b  to its folded state, as shown in  FIGS. 7 and 8 . The first surface  26  of the second panel  24  is thus inverted from its orientation when deployed for use, as will be seen in the bottom perspective view of the folded desk extension  10 , shown in  FIG. 8 . 
     Returning to  FIG. 2 , it will be noted that there is a receptacle  70  in the bottom or underside of the lower or first panel  12  for the storage of the second panel  24  therein. This second panel storage receptacle  70  provides for the nesting of the second panel  24  within the receptacle  70  and between the two linkage arms  36   a ,  36   b  and the two sides or edges  22   a ,  22   b  of the first panel  12  when the second panel  24  is in its stored state, as shown in  FIGS. 7 and 8 . Thus, the thickness of the entire device in its folded state is no greater than the thickness of the first panel  12 . This enables the desk extension  10  to be carried easily in a book bag, briefcase, or other similar container without requiring excessive room or space, but permitting other articles (e.g., books, a laptop computer, etc.) to be carried in the container with the desk extension  10 . 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.