Abstract:
An attachment apparatus assembly that is multi positional and attaches to a computer or desk chair is shown. The assembly attaches to a chair by use of an existing chair arm or by using a separate attachment member. The device provides support for the forearm and wrist while operating a computer mouse by allowing the user to rest their forearm on a chair arm that has a stowable work surface on its top surface. The work surface is vertically adjustable and can go from a myriad of horizontal work positions in front of or to the side of the user, and folds down into a stowed away position to the chairs side when not in use. The work surface may be utilized to operate a keyboard from by positioning the work surface over the users lap. In one embodiment the armrest is also horizontally positional.

Description:
[0001]     This application claims priority from Provisional Application Ser. No. 60/591,657 filed Jul. 28, 2004. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to a chair and table combination, in particular a chair arm having a stowable table with an integrated mouse pad. The chair arm is positional relative to the person sitting in the chair thereby allowing the user to position the table in the most ergonomic and comfortable position for operating a keyboard and/or a computer mouse positioned on the table. Furthermore, the chair arm has an armrest allowing the user to rest their arm on the rest while using the computer mouse.  
       BACKGROUND OF THE INVENTION  
       [0003]     Ergonomics as it relates to computer use is a field in need of innovation. Concerns involving the lack of proper positioning of a persons body while operating a computer keyboard and mouse are growing rapidly. Of particular concern are a person&#39;s back and arm position while operating a computer. The operation of a computer primarily involves inputting data through use of a keyboard and the use of a computer mouse for moving a curser and clicking the mouse.  
         [0004]     Typically, these operations are performed in a seated position for long periods of time. Accordingly, these operations are the cause of a great number of stress related injuries. Repetitive motion injuries such as carpel tunnel syndrome and tendonitis are injuries that are common but avoidable with proper ergonomic posture during use of the keyboard and mouse.  
         [0005]     Ergonomic devices have been developed to address these issues. For example, chairs have become high tech with the ability to be positioned to suit the user&#39;s needs and comfort level. Also, articulating arms that attach to desktops have been designed to provide support for a users arm while using a keyboard or mouse. Furthermore, mouse pads with a fold out arm that attach to a desktop and a chair desk having a stowable table with a mouse pad have been designed. In particular, these designs address the important and growing issue of relieving the strain put on the users back and arms and wrists. These devices concentrate mainly on supporting the users&#39; arms and wrists while operating a keyboard and mouse. The users&#39; arms and wrists are traditionally positioned on the desk in front of a computer monitor with the mouse pad being to the right of the keyboard. The problem is that there is no easy way to make using the keyboard and mouse comfortable and safe when they are located in a position that forces the user to stretch and bend the arms in positions that cause strain.  
         [0006]     An example of one device addressing the problem of using a computer mouse is shown in U.S. Pat. No. 6,347,771, issued to Lauzon et, Feb. 19, 2002 and entitled “Portable arm and mouse support for use with personal computers”. The device has a jointed arm with a mouse pad on one end and the other end is attached to a desktop. This design presents a problem with stability. In particular, the device is not able to withstand the weight a person will inadvertently put on the arm while positioning him or herself. The device is also cumbersome in that it does not stow away and must be attached and detached when not in use.  
         [0007]     Another such device, U.S. Pat. No. 5,490,710, issued to Dearing et al, Feb. 13, 1996 and entitled “Swing Arm Chair” shows a chair having a stow able table mounted onto a chair arm with an integrated mouse pad. The problem with this design is that it lacks the necessary adjustments to position the table up, down or rotationally so that the table may be usable while using a computer keyboard in conjunction with the mouse. Also, there is no support under the table to provide for any weight that one might put on the table. The mouse pad is in a fixed position and will likely incur strain and fatigue on the wrist because of the inability to position it where it is most comfortable. Finally, another problem is that this chair desk arm is not mountable on the standard office chair.  
         [0008]     In addition, U.S. Pat. No. 6,264,150 issued to Touzani, Oct. 5, 2004, and entitled “Ergonomic bi-level workstation” shows a chair desk with incorporated mouse pad. Many similar problems exist with this device as with that of U.S. Pat. No. 5,490,710 to Benden, et al., Aug. 12, 2003 and entitled “Support apparatus for a chair” in that the table is not positional vertically or horizontally. The mouse pad is in a fixed position to the user&#39;s right side thereby forcing the user&#39;s arm into a single position that may overtime become uncomfortable.  
         [0009]     Moreover, U.S. Pat. No. 6,311,939 issued to Christensen, Nov. 6, 2001 and entitled “Integrated mouse pad and wrist and arm support” shows a chair arm with an integrated mouse pad that is positional to a limited extent. A problem exists in this design in that the table or mouse pad is not stowable thereby causing a problem of being cumbersome when not in use. Although the arm is positional it has no linear tracking thereby limiting the mouse pad position to a fixed radius from the pivot points.  
         [0010]     Next, U.S. Pat. No. 6,352,303 issued to Hope, Mar. 5, 2002 and entitled “Arm rest mouse pad” shows a mouse pad with almost no means of positioning and no means of stowing it away. This chair mouse pad must be attached and detached when not in use. With the need for maneuverability of an office chair, leaving an extended mouse pad attached to a chair arm would create problems of mobility in the often cluttered and confined environment of computer workstations.  
         [0011]     Finally, U.S. Pat. No. 6,203,109 issued to Bergsten, et al., Mar. 20, 2001 and entitled “Ergonomic arm support” shows multi positional arm supports that are attachable to an office chair. Although this design provides good positioning of the arm supports in relation to the users body and keyboard, it does not provide for a stow able table with integrated mouse pad thereby being limited in its use as only supporting a person&#39;s arms. The design does provide for a mouse pad attachment in place of the armrest. This design creates a problem in that the mouse pad would not be hinged or stowable, and would not have the armrest to provide support for the arm while using the mouse.  
         [0012]     In today&#39;s workforce and confined environments compactness and speed are essential. In order for a chair arm or desk combination having an integrated mouse pad to be useful it should be quickly accessible, provide ergonomic positioning and have the ability to be quickly stowed away. If the device is cumbersome, unappealing, and too complicated it will not be used. The present invention provides a solution to these needs and other problems, and offers other advantages over the prior art.  
       SUMMARY OF THE INVENTION  
       [0013]     In accordance with one embodiment of the invention, a stowable work surface and attachment apparatus are used with an existing chair. The attachment apparatus comprise a vertically adjustable post having a first end that is configured and arrange to be attached to a chair, and a second end that is configured and arranged to rotatably support a mounting plate or bracket. The mounting plate, in turn, is operatively and movably connected to one or more arms that are configured and arranged to support the work surface. And the work surface comprises a computer peripheral interface surface and an armrest.  
         [0014]     In another embodiment, a stowable work surface and a portion of the attachment apparatus are used with an exiting chair armpost. In this embodiment, only the mounting plate of the attachment apparatus is used.  
         [0015]     In another embodiment, there are two stowable work surfaces that are movably connected to both sides of a chair. In this embodiment, which may be used with chairs having armposts or chairs without armposts, the work surfaces are configured and arranged so that they may create a substantially continuous work space in front of the chair.  
         [0016]     Still another object of the present invention is to provide a work space that can be separated and stowed along side of a chair when not in use.  
         [0017]     Still another object of the present invention is to provide a work surface that can be removably attached to the frame of an existing wheeled chair thereby converting the chair into a mobile work station.  
         [0018]     Still another object of the present invention is to provide a chair having a stowable work surface capable of supporting a laptop, and movable into a stowed position when not in use.  
         [0019]     Additional advantages and features of the invention will be set forth in part in the description which follows, and in part, will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIG. 1  is a front perspective view of the present attachment apparatus assembly with showing the stowable work surface in an extended horizontal position.  
         [0021]      FIG. 2  is a side perspective view of the present attachment apparatus assembly in an extended horizontal position directly in front of a chair.  
         [0022]      FIG. 3  is a side perspective view of the present attachment apparatus assembly with the stowable work surface in a stowed away position to the side of the chair.  
         [0023]      FIG. 4  is an exploded perspective view of the present attachment apparatus assembly.  
         [0024]      FIG. 5  is an exploded perspective view of the attachment apparatus assembly of  FIG. 4  showing greater detail of the swing arm mechanism.  
         [0025]      FIG. 6  is a detailed side view of the bracket.  
         [0026]      FIG. 7  is a top view of the attachment apparatus assembly of  FIG. 4  showing various positions of the stowable work surface.  
         [0027]      FIG. 8  is a partial perspective view of the second arm positioned in the second block.  
         [0028]      FIG. 9  is an end view of the second block shown from the direction of arrows in  FIG. 8 .  
         [0029]      FIG. 10  is a partial perspective view of the first arm with the first block attached to its end.  
         [0030]      FIG. 11  is a side view of the bracket.  
         [0031]      FIG. 11   a  is a top view of the bracket with linear tube shown in hidden lines.  
         [0032]      FIG. 12  is a side view of the first arm in an alternate embodiment of attachment apparatus assembly.  
         [0033]      FIG. 12   a  is a top view of  FIG. 12 .  
         [0034]      FIG. 13  is an exploded perspective view of an alternate embodiment of attachment apparatus assembly  FIG. 4  and shows an articulating armrest and a mounting assembly having an adjustable post arm.  
         [0035]      FIG. 14  is a detailed exploded perspective view of the articulating armrest assembly of  FIG. 13 .  
         [0036]      FIG. 15  is a perspective view of the alternate embodiment of the arm rest in  FIG. 13 .  
         [0037]      FIG. 16  is a perspective view of the alternate embodiment of the mounting assembly shown in  FIG. 13 .  
         [0038]      FIG. 17  is an exploded perspective view of an alternate embodiment of present attachment apparatus assembly and shows a glide block assembly and pivot block having linear sliding members.  
         [0039]      FIG. 17   a  is a detailed perspective view of the alternate embodiment of the glide block assembly of  FIG. 17 .  
         [0040]      FIG. 18  is a detailed perspective view an alternate embodiment of the pivot block shown in  FIG. 17  that is attachable to a post arm.  
         [0041]      FIG. 19  is an exploded perspective view of an alternate embodiment of the pivot block shown in  FIG. 17  and is attachable directly to an existing chair arm via arm rest mounting bolts.  
         [0042]      FIG. 20  is an exploded view of an alternate embodiment of a means of positioning the present attachment apparatus assembly of  FIG. 17  and shows an articulating arm assembly with the pivot block attached.  
         [0043]      FIG. 21  is an exploded view of another alternate embodiment of positioning the attachment apparatus assembly of  FIG. 17  showing an extension arm attached to a swivel mechanism on a post arm.  
         [0044]      FIG. 22  is a perspective view of an alternate embodiment of the extension arm of  FIG. 21  and shows an extension arm having ball bearing track members instead of nylon linear glides.  
         [0045]      FIG. 23  is an exploded perspective view of an alternate embodiment of the present attachment apparatus assembly showing the extension arm in  FIG. 21  having a rotating hinge assembly with stowable work surface attached to it.  
         [0046]      FIG. 24  is an exploded perspective view of another embodiment of the present attachment apparatus assembly.  
         [0047]      FIG. 25  is an another embodiment in which each side of a chair is provided with an attachment apparatus and work surface which, when combined form a work space. 
     
    
     DETAILED DESCRIPTION  
       [0048]     As shown in  FIGS. 1, 2 , and  3  the present attachment apparatus assembly is designated in general by the numeral  10 , and includes as its principal components a stowable work surface  12  connected to a mounting plate  20  by means of a first arm  16  and a bracket  14 . The bracket  14  engages the first arm  16 , by means of a linear tube  15  and sleeve bushing  56  and provide a means for the stowable work surface  12  to be swing able and slid able, relative the mounting plate  20 . The mounting plate  20  is connectable to a chair  40  via an adjustable armrest bracket  26  and an arm support  27 . A second arm  18  is connected to the mounting plate  20  and supports the stowable work surface  12  in a horizontal position. A standard armrest  28  is mounted on top of the mounting plate  20  thereby sandwiching the mounting plate  20  between the standard armrest  28  and the adjustable armrest bracket  26 .  
         [0049]      FIGS. 1, 2 , and  3  show various positions of the stow able mouse pad  12  from the stowed away position shown in  FIG. 3  to an extended horizontal position directly in front of the chair arm as shown in  FIGS. 1 and 2 .  FIG. 2  shows the stowable work surface  12  extended and positioned over a user&#39;s lap. It will be understood by those skilled in the art that the stowable work surface  12  may be positioned in a myriad of positions.  
         [0050]      FIGS. 4 and 5  show with greater detail exploded views of the present invention showing a stowable work surface  12  in an extended horizontal position. The stowable work surface  12  in phantom as it may appear is connected to a mounting plate  20  by means of a steel rod or first arm  16  and a bracket  14 . The bracket  14  as shown in  FIGS. 6, 11 , and  11   a  is mounted to the underside of the stowable work surface  12  and comprises a generally plain body and a linear tube  15  having a sleeve bushing  56  that slidably engages the first arm  16  and allows the stowable work surface  12  to relative the mounting plate  20 . The stowable work surface  12  may rotate about a bolt  36  that passes through apertures  39  and  41  of the bracket  14  and thrust washer  38 , respectively. Preferably, the bolt  36  is threaded into a threaded insert  21  located in the underside of the stowable work surface  12 , thereby securing the stowable work surface  12  to the bracket  14 . The thrust washer  38  is positioned between the underside of the stowable work surface  12  and the bracket  14  thereby allowing the stowable work surface  12  to frictionally engage the bracket  14  and to pivot via the bolt  36  and thrust washer  38 . The first arm  16  is mounted to and frictionally engages the mounting plate  20  via a first block  24 , which is attached to the end of the first arm  16  and which frictionally engages the underside of the mounting plate  20 . See, for example,  FIG. 5 . It will be understood by those skilled in the art that the first block  24  and is generally disc shaped having a through hole or aperture  25  and two opposing flat sides one of which provides a bearing surface on which the first block  24  rotates. The first block  24  has an aperture  25  extending through the center axis of the first block  24 . A thrust washer  27  may be positioned between the first block  24  and the mounting plate  20 . The first block  24  is attached to and frictionally engages the mounting plate  20  via a bolt  36  which passes through apertures  29 ,  27   a , and  25  of the mounting plate  20 , thrust washer  27 , and first block  24  respectively, and which is engaged by a nut  34 . It will be understood by those skilled in the art that by tightening or loosening the nut  34 , the resistance at which the swing arm pivots may be increased or decreased. An additional thrust washer  27  may be placed on the opposing flat side of the first block  24  to ensure a fluid pivoting motion. As shown the mounting plate  20  has a T-shape with the horizontal portion having a leg extending thereabove from the left side of the Tee, which allows a second arm  18  to be offset from the first arm  16 , and which allows the second arm  18  to be perpendicular to or cross over in front of a standard arm rest  28 . The lower portion of mounted plate extension  32  provides support that allows the mounting plate  20  to be secured to an arm rest bracket  26  via the mounting plate bolt holes  48  and arm rest mounting bolts  30 .  
         [0051]     A second arm  18  provides support for a work surface while in a horizontal position and comprises a second arm  18  which is engaged by a second block  22 . The second block  22  is shown in greater detail in  FIGS. 8 and 9 . The second block  22  is generally disc shaped having two opposing flat sides. On one flat side a threaded pin or stem  54  extends from the center of the flat portion of the disc, and provides a means for securing the second block  22  to the mounting plate  20 . The second block  22  has through hole or aperture  57  extending through the disc, perpendicular to its center axis. A sleeve bushing  56  comprised of nylon or other low friction material such as polytetraflouroethylene may be is fixed in the hole  57  thereby forming a pillow block through which the second arm  18  may move, allowing the second arm  18  to move into an extended or retracted position.  FIG. 3  shows the second arm  18  and the first arm  16  in a retracted position. The second block  22  frictionally engages the bottom of the mounting plate  20 . A thrust washer  38  is may be between the flat bearing surface of the second block  22  and the bottom of the mounting plate  20 . The threaded stud  54  passes through apertures  27   a  and  29  of the thrust washer  27  and mounting plate  20  respectively, and is engaged by a nut  34 . By tightening or loosening the nut  34  the resistance at which the second arm  18  pivots may be increased or decreased respectively. An additional thrust washer may be placed on the top side of the mounting plate  20  to ensure a fluid pivoting motion if desired. As shown in  FIG. 4 , the mounting plate  20  is positioned between an arm rest  28  and an adjustable arm rest bracket  26  by two mounting bolts  30 , which pass through apertures  50 ,  48  of the adjustable armrest bracket  26 , mounting plate  20  and mounting plate extension  32 , respectively. The armrest mounting bolts  30  are threaded into T-nuts  52  located on the underside of the standard armrest  28 . An arm support  27  doubles as a connecting means by which the adjustable armrest bracket  26  and stowable mouse pad  10  are attached to an office chair  40  of the type having a back  42 , a seat  44 , and a support structure  46 . The arm support  27  typically has four slots at its end, providing a means for bolting the arm support to the bottom of the chair seat  44 . It should be noted that the second block  22  need not be limited in use with the second arm  18  only, and may also be used in place of the first block  24  thereby allowing a swingable and slideable first arm  16  as well as a swingable and slidable second arm  18 .  
         [0052]      FIG. 7  shows various positions in phantom of the stowable work surface  12  with corresponding positions of the first arm  16  and second arm  18 . The stowable work surface  12  is shown in four different horizontal positions swinging from left to right and ending with the stowable work surface  12  in a vertical or stowed away position  53 . The second arm  18  is shown in a retracted or stowed away position  58 . From the stowed away position  53  the table may be lifted or swung into a horizontal position, and the second arm  18  extended to provide support for the stowable work surface  12 . The stowable work surface  12  may then be swung into any one of a multitude of positions including but not limited to the four positions shown. It will be appreciated by those skilled in the art that the stowable work surface  12  may also rotate or pivot independently relative to bracket  14  about bolt  36  as described in  FIG. 6 , thus allowing even greater positioning capacity.  
         [0053]      FIGS. 13 and 16  shows and alternate embodiment of the present invention having an attachment apparatus  59  that allows the stowable work surface  12  to be connected to a chair  40  that does not have existing arms. Here, a positional arm rest assembly  60  comprises an articulating arm  84   a ,  84   b  and a rotatable arm rest  76 . A post assembly includes as its principle components a post  68  which connects the stowable work surface  12  to a chair  40 . The arm housing  64  may be provided with a clamp  66  with which to secure the post  68  relative to the housing  64 . The bottom of the housing  64  terminates with a bracket  72  which is provided with mounting slots The post arm  68  is connected to the mounting plate  20  and provides the means to pivot as well as adjust the height of the stowable work surface  12  by engaging the post clamp  66  and a sleeve bearing located inside the arm housing  64  near the bottom. The post clamp  66  has an inside diameter slightly larger than the outside diameter of the post arm  68  thereby allowing it to slide inside the inside diameter of the post clamp  66 . The clamp  66  is of a typical design used on shafts for positioning and holding them in place. Clamp  66  includes a vertical slot  73  with an intersecting bolt hole and a lever with a threaded bolt extending through the hole thereby allowing the post clamp  66  to constrict around the arm  68  by turning the lever and decreasing the diameter of the clamp  66  inside diameter.  
         [0054]      FIG. 14  shows in greater detail the articulating arm  60  in  FIG. 13 . The articulating arm  84   a ,  84   b  allows armrest  76  to rotate and thereby increase positioning capability. The articulating arm comprises a lower arm  84   a  and an upper arm  84   b  joined together at one end by a pivot pin  86  which allows the two arms to act as a hinge having a common pivot pin. A thrust washer  88  is positioned between the lower  84   a  and upper  84   b  arms with the pivot pin  86  extending through the thrust washer  88 .  
         [0055]     The upper arm  84   b  has a through hole or aperture  90  opposite the end of the pivot pin  86 . The aperture  90  is used as a bushing through which a downwardly depending stem  80  of the arm rest  76  is inserted, allowing the arm rest  76  to be seated and to pivot about the center axis of the aperture  90  at the end of the top arm  84   b . A bushing may be inserted into the through hole or aperture  90  to allow smoother rotation, if desired. The lower arm  84   a  has a hole  94  opposite the end of the pivot pin  86  through which the upwardly extending stem  70  of the post projects. As shown, the stem  70  projects through a hole  92  in the center of the mounting plate  20  and extends out the top of the mounting plate  20  and through hole  94  located at the end of the lower arm  84   a  opposite the pivot pin. A thrust washer (not shown) may be positioned between the top of the mounting plate  20  and the bottom of the lower arm  84   a . A retainer ring, circlip, or similar fastening may be used on the end of the stem  70  to hold the articulating arm  84   a ,  84   b  onto the stem  70 .  
         [0056]      FIG. 15  shows a rotatable armrest  76  having a cupped shape that is configured to receive the forearm of a user. The arm rest  76  may be provided with a padded portion  78  made of a resilient material such as foam or sponge rubber which overlays the rigid body of the arm of the armrest  76 . A trunnion  82  is located on the convex or bottom surface of the armrest  76 . The trunnion  82  has a downwardly depending stem  80  inserted into the through hole or aperture  90  located at the end of the upper arm  84   b  of the articulating arm  84   a ,  84   b.    
         [0057]      FIGS. 17 and 17   a  show yet another alternate embodiment of the present invention referred to in general by the numeral  104 . In exploded view the main components of the alternate embodiment, are a stowable work surface  12  that is slid ably connected to a block  96  by means of a first arm  112 . The first arm  112  has a work surface attached to its end by means of a bracket  118 ; the opposing end slidably engages the pivot block. The block  96  is connected to the end of an extension arm  120 . The extension arm  120  is slidably connected to a block  122 . The glide block  122  is mounted to a post  68   a  by a swivel base  136  located on the upper end of the post  68   a . The post  68   a  is attached to the chair by means of a post arm assembly  59  as previously described. In greater detail the stowable work surface  12   a  is shown in an extended vertical folded down position ready to slide back to its stowed away position through a channel  102 . Shown in phantom in  FIG. 17 , work surface  12   a  is in an extended horizontal position. The stowable work surface  12  may pivot about the vertical and horizontal and is extendable by two linear slide mechanisms the block  96  and the block  122 . The stowable work surface  12  pivots and slides by means of a first arm  112 .  
         [0058]     The first arm  112  is connected to a second arm  114  by bar  116 . The first arm  112  and second arm  114  each have a threaded hole at their respective end for receiving threaded fasteners. The first arm  112  and second arm  114  are connected together after inserting the arms through parallel apertures  100  in the block  96 . The fastening elements  142  includes a shoulder that prevents over-tightening and allows the first arm  112  to rotate, thereby allowing both arms  112  and  114  to slide in unison and maintain the ability of the first arm  112  to also rotate with the shoulder of the fastening element  142  acting as a shaft and the arm hole acting as a bearing. The block  96  is of a rectangular shape having two parallel holes  100 , one located on each end of the block and extending therethrough. Each hole  100  may include a plastic bushing that slidably engages the first arms  112  and  114 . The block  96  also has an opening or channel  102  in the bottom portion of the block and located between the two parallel holes  100  of the block  96 , and closest to the first arm  112 . The channel  102  extends through the block from one side to the other and is generally parallel to the holes  100 . The channel  102  provides an opening in the block  96  so the work surface may be moved into a retracted and stowed position. The block  96  has a through hole  110  extending through the block from top to bottom. The block  76  is mounted to the end of the extension arm  120  by extending a bolt through the throughhole  110  through a nylon washer, and through the block mounting hole located at the end of the extension arm  120 . A nut  34  is screwed onto the end of the bolt thereby frictionally engaging the pivot block  96  with the extension arm  120  with a nylon thrust washer between them. The nut is tightened to increase or decrease the resistance at which the block  96  rotates.  
         [0059]     An arm rest mounting hole  111  is located near the center of the block  96  allowing the stem  80  of the armrest  75  to be inserted in the hole and the trunnion  82  to be seated upon the block thereby allowing the arm rest to pivot. The extension arm  120  comprises a longitudinal flat bar having a top surface and a bottom surface with two ends opposite each other and two sides opposite each other. A block mounting hole  126  is located on one end the opposite end is inserted into a block  122 . The block  122  comprises a top plate  124  and a bottom plate  124   b . The two plates are generally parallel to each other and retain channel elements  128  therebetween. The channel elements  128  are generally rectangular in shape and have a U shaped channel  134  extending the length of the glide. The channel elements  128  may be made of nylon, polytetraflouroethylene, or other material that is used for making a bushing. The U shaped channel  134  has 3 sides a top a bottom and a side. The top and bottom sides are at a distance from each other approximately equal to the thickness of the extension arm  120 . The glides are positioned between the glide plates  124  and  124   b  opposite each other one on each side of the plates so that the U shaped channels  134  are facing each other. The channels  134  create a slot into which the end of the extension arm  120  opposite the pivot block mounting hole  115  is inserted. The extension arm  120  slides back and forth inside the channel elements  128  relative to the block  122 . The channel elements  128  are fastened to the glide block plates  124  and  124   b  by bolts that extend through apertures  130  in the top plate  124 . The bolts extend through corresponding holes in the channel elements  128  and extend into threaded apertures in the bottom glide plate  124   b  (not shown). The block  122  can rotate 360 degrees and is seated on a swivel base  136 . The swivel base  136  is a round disc shaped member having a threaded hole  132  located at its center. The swivel base  136  is located on the top end of a post  68   a . The block  122  is mounted onto the swivel base by a conventional threaded bolt extending through a pivot bolt hole located at the center of the bottom plate  124   b  and through a thrust washer and threaded into the threaded hole  132  in the swivel base  136 .  
         [0060]      FIG. 18  shows an alternate embodiment of the present invention having a pivot block  96  as described in  FIG. 17  mounted directly to a post  68 . The block is mounted onto the post  68  at throughhole  115  located in the center of the block  96 . The stem  70  of the post arm  68  extends through the hole  115  and extends through the top of the block  96 . The bottom of the block  96  is seated on a seat or shoulder  71  of post  68 . A shroud  140  may be attached to the pivot block by means of screws  144  inserted through apertures  138  in the shroud  140  and screwed into threaded holes  137  in the pivot block. An arm rest may be attached to the top of the shroud  140 . An armrest may also be attached to the pivot block as shown in  FIG. 17 .  
         [0061]      FIG. 19  shows another alternate embodiment of the present invention showing the block  96  having an extension  98  extending therefrom. The extension  98  allows the block  96  to be mounted to an adjustable bracket  26  as shown in  FIG. 4 . Arm rest mounting bolts  30  extend through the bracket bolt holes  50  (see  FIG. 4 ) and through apertures  108  in the pivot block and extension  98 , and into threaded apertures  52  the underside of the arm rest  28 .  
         [0062]      FIG. 20  shows an alternate embodiment of the present invention having an articulating arm  62  interposed between the block  96  and post  68   a . As will be understood, the articulating arm increases the range of motion by which the stowable work surface  12  may be moved. The articulating arm  62  comprises a lower arm  146  and an upper arm  148  joined together by a bolt  154  which allows the two arms to act as a hinge and swivel via the pivot pin  154 . The articulating arm is of a common design and has been shown earlier in  FIG. 14 . The lower arm  146  has a hole  150  opposite the its hinged end. The bolt  152  extends through the hole and threads into the threaded hole  132  in the swivel base  136 . A thrust washer  38  may be positioned between the swivel base  136  and the lower arm  146 . The upper arm  148  has a throughhole or aperture  152  located on its end opposite its hinged end. A bolt  36  extends through a hole  162  in block  96 , through the thrust washer  38  and through the throughhole or aperture  152  at the end of the arm  148  and is secured via a nut  34 . The nut is tightened to allow the block to pivot freely with some resistance.  
         [0063]      FIG. 21  shows an alternate embodiment of the present invention having an extension arm  157  with channel elements  156  extending the length of the extension arm  157  and secured to the underside of the arm by fastening elements  160  that extend through apertures  161  in the extension arm  157  and screwed into the channel elements  156 . The channel elements  156  are a longer version of channel elements  128  in  FIG. 17   a . The extension arm  157  is configured so that the U shaped channels  163  slide along the edges of a rectangular plate  155 . The plate  155  is rotatably mounted onto the swivel base  136  by bolt  36  which extends through a hole  158  located in the center of the plate  155  through a thrust washer  38 , and into threaded hole  159  located in the center of the swivel base  136 .  
         [0064]      FIG. 22  shows an alternate embodiment of an extension arm  164  that is shaped like a channel having a top and two sides and an interior cavity. Two ball bearing glides  168  are secured to the interior walls of the channel and have mounting flanges  166  that extend towards the interior cavity  166 . The mounting flanges  166  have holes  170  that allow the extension arm  164  to be attached to plate having corresponding holes similar to plate  155  shown in  FIG. 21  but with corresponding attachment holes (not shown).  
         [0065]      FIG. 23  shows an alternate embodiment having an extension arm  157  as shown in  FIG. 21  with a rotating hinge assembly  171  attached to it. The hinge assembly is a known device used for stowing a desktop to the side of a chair used in classrooms and auditoriums. The mechanics will be briefly described here. A block  172  is mounted to the arm  157  by bolt  176  that extends through a hole  182  located in the center of the block and nut  180  is threaded onto the bolt. The block  172  rotates about the bolt  176 . The block  172  has two hinge pins  178  located at each end of the block which allows a hinge bracket  174  to be mounted and swivel perpendicular to the axis on which the block  172  swivels. The stowable work surface  12  is attached to the hinge bracket thereby allowing the stowable work surface  12  to be flipped up and rotated 180 degrees down and slid back via the extension arm  157 .  
         [0066]      FIG. 24  shows another alternate embodiment of the present invention having an extension arm  192  that does not slide. A block  184  having a block  96  thereto it allows the stowable work surface  12  to slide and rotate. An extension arm  192  is fastened to the swivel base  194  through an aperture  198  on one end of the extension arm  192 . The swivel base has a threaded stud  196  that extends upwardly from the center of the swivel base and extends through the hole  198  on the extension arm and where it is secured by a nut  34 . A thrust washer  134  may be placed between the swivel base  194  and the extension arm  192  to provide a smooth wear resistant surface on which the extension arm  192  may swivel. The block  184  is built in the same fashion as the extension arm shown in  FIG. 21 , but shorter in length. The block  184  comprises a plate  186  having two channel elements  188  secured to the underside thereof by conventional fastening elements that are received mounting holes  150 . A thrust washer  134  may be positioned between the block  184  and the block  96  to provide easy and smooth rotation of the pivot block  96 . A standard armrest  28  may be mounted to the pivot block  96 .  
         [0067]      FIGS. 25 and 25   a  shows a stowable work surface  12  with a partial oval shape having one flat edge. The stowable work surface  12  has a recess  200  cut into the top that is slightly deeper than the thickness of a mouse pad. A mouse pad  202  is placed in the recess allowing a ridge  204  around the perimeter of the work surface to extend beyond the height of the mouse pad thereby allowing the ridge to prevent a mouse from falling off the stowable work surface  12 . The stowable work surface  12  has a threaded insert  21  threaded into the bottom of the work surface and provides the means for bolting the work surface to the bracket  14  or bracket  118 .  
         [0068]     It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with details of the structure and function of various embodiments of the invention, this disclosure is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.