Abstract:
A multi-functional adjustable tray that mounts on the arm of a chair to provide a comfortably accessible work surface to support a computer mouse and other IO devices. The adjustable tray may be easily mounted to an arm of a chair and provides width, length, rotation, and storage adjustments. The adjustable tray includes a platform that is pivotally connected to a support device through a ball and socket connection device thus allowing wide degrees of latitude and flexibility of use so as to accommodate increased ease of use with the I/O device. The ball and socket connection device includes a mechanism for selectively restricting movement of the platform.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part application of a pending application, entitled Adjustable Work Surface filed by Daniel V. Steenson on May 5, 2006 with application Ser. No. 11/382,337 which is a continuation in part of a pending application, entitled ADJUSTABLE ARMCHAIR TRAY, filed by Daniel V. Steenson on Nov. 16, 2005, with application Ser. No. 11/281,572, which is a continuation-in-part application of a pending application, entitled ADJUSTABLE ARMCHAIR TRAY, filed by Daniel V. Steenson on Oct. 13, 2005, with application Ser. No. 11/250,654, which is a continuation-in-part application claiming the priority date from the issued patent entitled ADJUSTABLE ARMCHAIR MOUSE TRAY, filed by Daniel V. Steenson on Aug. 18, 2004, now U.S. Pat. No. 7,131,688. This application also claims priority to provisional application entitled COMPUTER WORK SURFACE, filed by Daniel V. Steenson on Jan. 5, 2006 with application Ser. No. 60/756,682. These applications are incorporated herein by these references.  
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention generally relates to the field of computer accessories. More particularly, the present invention provides an adjustable tray that may be easily mounted to the arm of a chair to provide a generally planar working surface to support a computer mouse and other accessories, devices and objects.  
       BACKGROUND OF THE INVENTION  
       [0003]     Computers are operated through the use of peripheral systems and devices such as a keyboard, roller mouse or optical mouse, pen, joystick, keyboard, keypad, roller ball, trackball, personal digital assistant, cell phone, or similar device or other device, referred to collectively as IO devices. IO devices enable a user to interact with a computer or network to send or receive information, make decisions, and carry out various other functions. Direct physical contact with, and therefore close proximity to, these devices are essential to their operation.  
         [0004]     However, in most circumstances a computer user works at a desk and leans forward or sideways from a comfortable sitting position to reach a keyboard or mouse on a desk or other flat surface. Reaching for the keyboard or the mouse in this way makes it very difficult to maintain proper posture and operate the computer comfortably. Use of IO devices on a desktop stresses the back, shoulder and the wrist. For wrist stress and carpal tunnel syndrome, numerous products, such as ergonomically shaped mice and wrist supports, attempt to address the symptoms of this stress without addressing the awkward positioning that often causes strain.  
         [0005]     Additionally, persons with debilitating injuries may find that reaching to a desk to use IO devices is difficult or painful. Accordingly, there is a need for a surface for supporting one or more IO devices that maintains a position so that the user may maintain ergonomically correct posture and wrist position.  
         [0006]     The purpose of the foregoing Abstract is to enable the United States Patent and Trademark Office and the public generally, and especially the scientists, engineers, and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection, the nature and essence of the technical disclosure of the application. The Abstract is neither intended to define the invention, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.  
         [0007]     Features of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein only the preferred embodiments of the invention will be described and shown, simply by way of illustration of the best modes contemplated to manifest the invention. As will be realized, the invention is capable of modification in various obvious respects all without departing from the invention. Accordingly, the drawings and description of the preferred embodiments are to be regarded as illustrative in nature, and not as restrictive in nature. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a top view of an embodiment of an armchair tray.  
         [0009]      FIG. 2  is a side view of the embodiment of  FIG. 1 , as mounted on a chair arm.  
         [0010]      FIG. 3  is a front view of the embodiment of  FIG. 1 .  
         [0011]      FIG. 4  shows an embodiment of a movable fastener.  
         [0012]      FIG. 5  is a perspective view of the embodiment of  FIG. 1 .  
         [0013]      FIG. 6  is a side view of an embodiment of the invention where the armchair stop is secured directly to the chair arm.  
         [0014]      FIG. 7  is a side view of an embodiment of an armchair tray having a rotatable joint.  
         [0015]      FIG. 8  is a side view of an embodiment of an armchair tray having a slideable guide.  
         [0016]      FIG. 9  is a top view of an embodiment of a platform for supporting an IO device.  
         [0017]      FIG. 10  is a perspective view of the platform of  FIG. 9 .  
         [0018]      FIG. 11  depicts a method of supporting a keyboard using two embodiments of a platform.  
         [0019]      FIG. 12  depicts an embodiment of a platform for supporting two IO devices.  
         [0020]      FIG. 13  is a bottom view of an embodiment of a platform and an embodiment of an arm for supporting the platform.  
         [0021]      FIG. 14  is a top view of another embodiment of an arm.  
         [0022]      FIG. 15 . is a top view of another embodiment of a platform and associated connection device.  
         [0023]      FIG. 16  is a side view of another embodiment of the present invention.  
         [0024]      FIG. 17  is a side view of one embodiment of a rotational fastener of the present invention.  
         [0025]      FIG. 18  is bottom plan view of the embodiment of  FIG. 17 .  
         [0026]      FIG. 19  is a top plan view of another embodiment of the present invention.  
         [0027]      FIG. 20  is a partial, side view of the embodiment of  FIG. 20 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0028]     While the invention is susceptible to various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed; on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims.  
         [0029]      FIG. 1  shows a top view of an embodiment of the adjustable tray  10 . The adjustable tray  10  includes a platform  12 , which provides a generally planar surface for IO devices and other writing utensils. Additionally, the platform  12  may be used to write notes, secure a remote control, hold food or a beverage, or facilitate other similar uses. The adjustable tray  10  may be used on any device or location that is equipped with a chair arm or substantially equivalent structure. For example, many automobile seats are now equipped with armrests that the adjustable tray  10  would easily adapt to fit for the previously mentioned uses.  
         [0030]     The shape defined by the perimeter of platform  12  may vary with the application, including square, rectangular, circular, or other shapes. The chairs to which the adjustable tray  10  may be attached are often mounted on rollers. In normal operation, the user may roll the chair and cause the platform  12  to contact a desk or other external object. To avoid being captured between the external object and the chair arm, the perimeter of the platform  12  may be shaped generally as an oval or an ellipse in some embodiments, and preferably modified by a peak  15 . Peak, in this context, means a region of the perimeter that converges more sharply than an oval or ellipse. The overall oval shape of the platform  12  allows the platform  12  to rotate to either side of the chair arm and slide along the object as the object gently pushes it aside. The peak  15  ensures that the platform  12  swings to one side or the other, rather than being captured along the long axis of the chair arm. The perimeter of the platform  12  need not be perfectly elliptical; rather, the perimeter of the platform  12  preferably curves smoothly along the sides, and curving more sharply on the end.  
         [0031]     The platform  12  and other parts of the adjustable tray  10  may be built or molded of any material that allows for strength and ease of use such as wood, plastic or other similar materials. The platform  12  may incorporate at least one retainer  14 , preferably located around the periphery of the platform  12 , to allow a mouse pad, or other devices to be retained within the perimeter of the platform  12 . The retainer  14  provides a boundary that prevents IO devices or other materials from falling off the platform  12 . In some embodiments, one or more discrete retainers  14  may be placed on all sides of the platform  12  to assure that a device does not fall off any side of the platform  12 .  
         [0032]     A pad  16  or other similar material may be positioned on top of the platform  12  and configured to be easily replaced when worn out. The pad  16  is preferably made of materials similar to those used for basic stand-alone computer mouse pads, typically neoprene with a nylon coating. Additionally, the pad  16  may be rubber, plastic, nylon, hook and loop fastener, or other material that facilitates the operation of an IO device. To prevent the pad  16  from falling when the platform  12  is placed in a stored or disengaged position, pad  16  may be held in place by adhesive or restraining tabs (not shown) protruding from the retainer  14 . In other embodiments, the pad retainers may be a molded part of the platform  12 , or clamps, tie downs, hook and loop fasteners, snaps or other elements may be used to maintain the correct positioning of the pad  16  on the platform  12 .  
         [0033]     In some embodiments of the present invention, IO devices may be rigidly attached to the platform  12 , eliminating the need for retainer  14 . Alternatively, the platform  12  may be integrated with the case of the IO device, so that the platform  12  and the IO device are presented to the user as a unit.  
         [0034]      FIGS. 9 and 10  depict an embodiment with an alternative retainer assembly. Retaining strip  17  is placed around pad  16  and attached to platform  12 . While  FIG. 9  shows pad  16  and retaining strip  17  attached to platform  12  with an adhesive, in other embodiments pad  16  and retaining strip  17  may be affixed to platform  12  with an adhesive, clips, or retaining tabs. Retaining strip  17  presents a relatively high friction surface to the IO device, such as a computer mouse, so that the IO device is prevented from easily sliding off the surface of pad  16 . High friction in this context means a higher friction coefficient than the coefficient of friction between pad  16  and the IO device. Coefficient of friction is a scalar value that describes ratio of the force of friction between two bodies (in this case, between the IO device and pad  16  or retaining strip  17 ) and the force pressing the bodies together.  
         [0035]     In some embodiments, the top surface of retaining strip  17  is level with the top surface of pad  16 , so an IO device may slide or roll partway onto retaining strip  17 . In many applications, this will present a progressively increasing resistance to the user of the IO device as the user moves the IO device near the edge of platform  12 . In some embodiments, retaining strip  17  is level with the pad  16  along the boundary between retaining strip  17  and pad  16 , and retaining strip  17  gets progressively thicker as it approaches the perimeter of platform  12  along a radial line extending roughly from the center of platform  12  to the perimeter of platform  12 ; in other words, retaining strip  17  is thicker along the edge of platform  12  than it is next to pad  16 . In the embodiment shown in  FIG. 9 , retaining strip  17  does not completely encircle pad  16 , leaving a region open near the user&#39;s wrist to extend the usable area for a mouse or similar IO device. In other embodiments, retaining strip  17  completely encircles pad  16 .  
         [0036]     In a related embodiment, retaining strip  17  may be constructed of hook and loop material, such as Velcro®, which may be used to retain an IO device such as a keyboard. For example, retaining strip  17  may be constructed of the loop side of the material, and one or more strips of the hook side may be attached to the bottom of a keyboard. The keyboard may be placed on platform  12  so that the hook material engages the loop material, preventing the keyboard from sliding on the surface of platform  12 . In this way, the keyboard is securely attached to platform  12  for use, but easily removed to use platform  12  for another purpose or to allow the user to exit the armchair. In this embodiment, retaining strip  17  may completely encircle pad  16  or may leave an open region as shown in  FIG. 9 .  
         [0037]      FIG. 10  illustrates that a mouse  102  or similar IO device is retained by retaining strip  17  when platform  12  is tilted to the side. Embodiments of platform  12  may be used in applications other than a removable armchair tray as depicted in  FIGS. 1 through 8 . For example, platform  12  may be used on a slide-out keyboard drawer found on some desks, or on ergonomic keyboard and mouse supports. The embodiments shown in  FIGS. 9 and 10  are particularly useful in the applications where the IO device is supported by tiltable structure, as often found on ergonomic keyboard supports.  
         [0038]     Referring again to  FIG. 1 , a movable fastener  18  passes through a hole  20  in the platform  12 , pivotally securing the platform  12  to an armchair stop  22 . The movable fastener  18  may be a threaded nut and bolt, a pin connection with a threaded end for tightening purposes, or any other element that provides a rotational pivot for the angular adjustment of the platform  12 , while still interconnecting the platform  12  with the armchair stop  22 . In the embodiment of movable fastener  18  shown in  FIG. 4 , the movable fastener  18  includes a threaded bolt  40 . Threaded nut  42  screws onto the shank of bolt  40 , capturing the platform  12  between threaded nut  42  and the head  44  of bolt  40 . Tightening the nut  42  secures the platform  12  and prevents it from rotating; loosening nut  42  slightly releases the platform  12  enough to allow rotation to a comfortable position.  
         [0039]     The movable fastener  18  is preferably ergonomically designed or covered so that it does not interfere with the user during use of devices on the adjustable tray  10 . This may be accomplished by incorporating a rounded or other shape that allows it to be easily tightened while simultaneously maintaining user comfort. Rounded, in this context, means that the nut  42  has no sharp edges exposed to the user when installed.  
         [0040]     Referring now to  FIG. 2 , a side view of the embodiment of  FIG. 1 , the armchair stop  22  is shaped to be positioned directly against a chair arm  24  while preventing the platform  12  from sliding toward the back of the chair. On some chairs, that position will be where the armrest transitions from horizontal to vertical. The adjustable tray  10  will also work on different styles of arms and chairs with the only general compatibility requirement being that the chair has an armrest equivalent. The armchair stop  22  has a curved or slanted region  26  to accommodate any curvature of chair arm  24 . When the region  26  of armchair stop  22  abuts the chair arm  24 , the chair arm  24  provides additional support to the adjustable tray  10 .  
         [0041]     In one example embodiment, the platform  12  is constructed on two levels: a first level that supports an IO device, and a second level lower than the first level through which the fastener  18  passes. This two-tier structure allows the first level to be generally level with the chair arm, so that the user&#39;s wrist is approximately straight when using the input device without interference by the movable fastener  18 . Optionally, a wrist pad or cover (not shown) may be placed on the second level to help support the user&#39;s wrist.  
         [0042]      FIG. 3  is a front view of the embodiment shown in  FIG. 1 . Referring to  FIGS. 1, 2 , and  3 , the movable fastener  18  flexibly secures the platform  12  to armchair stop  22  by passing through the hole  20  in the platform  12 , through a slot  28  in the armchair stop  22 , and into a cavity  30  ( FIG. 3 ) in armchair stop  22 . The slot  28  in the armchair stop  22  has a generally horizontal top leg  32  ( FIG. 1 ) having curved regions on each end and connecting to two generally vertical legs  34  on either side of armchair stop  22  ( FIG. 2 ). The slot  28  has additional generally horizontal side legs  36  on either side of armchair stop  22 , terminating in an enlarged region  38 . The shape of slot  28  allows the platform  12  to be positioned on the top of armchair stop  22  for use, or positioned to either side of chair arm  24  by sliding the fastener  18  from horizontal leg  32  into one of vertical legs  34 . Vertical legs  34  need not be precisely vertical: they may slope fore and aft or side-to-side to accommodate chair arms of various shapes. Similarly, horizontal side legs  36  need not be precisely horizontal.  
         [0043]     As a result, a person may use the adjustable tray  10  with the platform  12  horizontal and then rotate the platform  12  and the movable fastener  18  within the slot  28  so that the platform  12  is in a vertical storage position. The transition is easily made by loosening the movable fastener  18  slightly, and then sliding the movable fastener  18  and the connected platform  12  within the slot  28  from the horizontal plane to the vertical plane. In another embodiment, the slot  28  has only one vertical leg  34  so that the platform  12  may be stored only on one side of the chair arm  24 .  
         [0044]     Referring to  FIG. 2 , the platform  12  may be removed from the armchair stop  22  by sliding the movable fastener  18  along the leg  36  of the slot  28  to enlarged region  38 . Enlarged region  38  is sufficiently large to allow an end of movable fastener  18  to pass through, releasing the movable fastener  18  and the platform  12  from the armchair stop  22 . In some embodiments, a top leg  39  connecting with slot  28  may be included to allow additional adjustability of the fore and aft position of platform  12 .  
         [0045]     The embodiment of the movable fastener  18  shown in  FIG. 4  has a threaded bolt  40  and an ergonomically shaped threaded nut  42 . Bolt  40  has a head  44  that is small enough to pass through enlarged region  38 , yet still engage legs  32 ,  34 , and  36  of slot  28 . An embodiment of bolt  40  has a frustoconical ring  46  circumvolving the shank of bolt  40  and one or more bosses  48  protruding from the shank of bolt  40 .  
         [0046]     The hole  20  in the platform  12  may be sized to allow the bolt  40  with the ring  46  to pass through as a press fit. After the ring  46  passes through the hole  20  ( FIG. 2 ), the bolt  40  is captured on the topside of the platform  12  by the ring  46  and on the bottom side by head  44 , while still allowed to move a short distance in an axial direction. The hole  20  may optionally be made of a smaller diameter at the upper end, to allow the ring  46  to easily pass through during assembly, while still capturing the bolt  40  during operation. In another embodiment, annular ring may be replaced with one or more barbs.  
         [0047]     One or more bosses  48  engage corresponding axial grooves or similar features in the hole  20  to prevent rotation of the bolt  40  relative to the platform  12  when the nut  42  is tightened, eliminating the need for a washer and facilitating tightening of the nut  42  to secure the platform  12 . While the bosses  48  are depicted as cylinders, the bosses  48  may be of any shape that engages the grooves and prevents rotation, including a polyhedron or hemisphere.  
         [0048]     The adjustable tray  10  further includes one or more guides  50  connected to the armchair stop  22 . Viewed from above as shown in  FIG. 1 , the guides  50  are approximately L-shaped on each end, and one leg of each guide  50  is inserted into a hole  58  and a hole  60  in the armchair stop  22 . Holes  58  and  60  are offset, permitting the legs inserted into the slot to be relatively long, accommodating both wide chair arms and narrow chair arms, where the legs overlap each other in the slots. In an embodiment shown in  FIG. 5 , the rear of the armchair stop  22  may include one or more recesses  62  sized to accommodate guides  50 , allowing guides  50  to be adjusted to accommodate a chair arm  24  narrower than armchair stop  22 .  
         [0049]     In the embodiment depicted in  FIG. 5 , the guides  50  are compressed against the sides of the chair arm  24  by at least one securing device  52 . The securing device  52  as herein defined includes, but is not limited to, a clamp, tape, bungee cords, string, tie cords, or straps. Each securing device  52  preferably passes around the chair arm  24  and guides  50  and is preferably fastened by a fastener  54 . Fastener  54  may be a Velcro fastener, a Tabler buckle, a clip, or similar buckling device. The compressive force of the devices  52  presses the guides  50  against the chair arm  24  and into the armchair stop  22 , effectively securing the adjustable tray  10 . This embodiment provides the advantage of simplicity and allows the adjustable tray  10  to be quickly and easily mounted to the chair arm  24  with ease.  
         [0050]     Another embodiment may include at least one strap slot or loop in each guide  50  in which to thread the securing devices  52  to compress and secure the guides  50  to the chair arm  24 . The strap slots preferably run a substantial length of the guides  50  allowing the securing devices  52  to be slid or moved to accommodate the configuration of the chair arm  24  and particularly the support members.  
         [0051]     In this embodiment, the guides  50  each have a tab  56  on the end furthest from the armchair stop  22  to prevent securing devices  52  from slipping off the ends of guides  50 . Guides  50  may also be tapered to better conform to curved chair arms.  
         [0052]     Referring to  FIG. 2 , the guides  50  may curve downward in the region  64  nearest the armchair stop  22  so that the platform  12  is approximately level with the uppermost surface of guides  50 . Without the curved region  64 , the platform  12  would be positioned above the chair arm  24 , causing the user&#39;s wrist to flex upward when using a mouse or other IO device, potentially causing carpal tunnel stress within the wrist. In another embodiment, a shallower or deeper curve positions the platform  12  above or below the chair arm  24 , respectively, which may be comfortable for some users. Curved region  64  need not be smoothly curved in the S-shape shown; it may descend sharply in a Z-shape or with perpendicular angles.  
         [0053]     Adjustable tray  10  may include multiple sets of guides  50 , each set tapered, curved, and including features that best fit a class of chair arms. The user may then select the set of guides  50  that best fits the user&#39;s chair.  
         [0054]     In another embodiment, shown in  FIG. 8 , each guide  50  may be inserted into a corresponding cavity  65  in chair arm  24 . The walls of the cavity  65  support the guide  50 , which in turn supports the armchair stop  22 . Each guide  50  may slide in and out of the cavity  65 , allowing the user to place the platform  12  a comfortable distance away from the chair arm  24 . In some embodiments, the chair arm  24  has an additional cavity  67 , as shown in  FIG. 8 , adapted to accept the armchair stop  22 , so that the armchair stop  22  may be retracted into the chair arm  24  and out of the way of the user. In some embodiments, only one guide  50  is required, because there is no need to adapt the adjustable tray  10  to fit the width of the chair arm  24 .  
         [0055]     Guides  50  may be eliminated by securing armchair stop  22  directly to chair arm  24 , as shown in  FIG. 6 . Armchair stop  22  may be secured with one or more permanent fasteners  68 , such as screws or glue, or removable fasteners, such as key and slot hangers. Using a key and slot hanger, one or more keys attached to armchair stop  22  engage slots in chair arm  24 . Each slot has an enlarged region so that the key may be disengaged from the slot, allowing removal of the adjustable tray  10 . It is preferable to install the slots on chair arm  24 , rather than the key, so that the key does not protrude from chair arm  24  when armchair stop  22  is removed.  
         [0056]     The armchair stop  22 , the guides  50 , and the securing devices  52  are preferably lined with a cushioning material  66 , as shown in  FIG. 1 . The cushioning material  66  allows the guides  50  and the armchair stop  22  to be tightened against the surface of a chair without scratching or other marring of the chair. Cushioning material  66  also provides a non-slip surface that prevents movement during the use of the adjustable tray  10 . Cushioning material  66  may be any material such as rubber, plastic or cloth that prevents slippage and marring of the arm of the chair. In this embodiment, the cushioning material  66  is neoprene or other non-skid rubberized material used to form traditional stand-alone mouse pads.  
         [0057]      FIG. 7  shows an embodiment of the invention having rotatable joints that allow the platform  12  to be tilted to comfortably accommodate a user&#39;s hand and wrist position while using a keyboard or other IO device. In particular, a keyboard that is split into two parts, one for the left hand and one for the right hand, allows each keyboard segment to be rotated to fit the user&#39;s hand when the user&#39;s arm is resting on the chair arm or held comfortably above or to the outside of the chair arm. The left keyboard segment is preferably tilted or rotated counter-clockwise from the user&#39;s perspective; the right keyboard segment is preferably tilted or rotated clockwise. The angle of rotation varies with the user, the layout of the chair arm, and the size and configuration of the keyboard. Referring to  FIG. 7 , the platform  12  is attached to an arm  70  that is divided into three segments by a first rotatable joint  72  and a second rotatable joint  74 . An inboard segment  76  of the arm  70  is attached to the armchair stop  22  by the movable fastener  18 , and an outboard segment  78  of the arm  70  is attached to the platform  12 . A middle segment  80  connects rotatable joints  72  and  74 . In this embodiment, the outboard segment  78  rotates on a first pin  82 , and the middle segment  80  rotates about a second pin  84 .  FIG. 7  shows the outboard segment  78  in an exemplary first position where the user&#39;s wrist extends upward, and an exemplary second position where the user&#39;s wrist flexes downward, designated as  78 ′. The rotation of segment  78  about joint  74  is not limited to the positions shown and may extend to wider or narrower angles.  
         [0058]     The outboard segment  78  may be prevented from rotating beyond the desired angle by static frictional contact between the middle segment  80  and the outboard segment  78 . The static friction may be overcome by applying a manual moment to the outboard segment of the arm  70 . The ease of rotation may be controlled by using a bolt, machine screw, or lag screw with a knurled head as the pin  82  so that the bolt may be tightened or loosened to control the friction between the segments. An optional rotational control device  86  may be used to control rotation, such as a rubber washer, fiber washer, toothed surfaces on segments  78  and  80 , or other suitable rotation controlling device. Rotation of joint  74  may be controlled in a similar manner, including use of a rotation control device  86  between the surfaces of middle segment  80  and inboard segment  76 .  
         [0059]     The embodiment shown in  FIG. 7  allows the platform to be rotated about the long axis of the arm  70  via rotatable joint  72 . In other embodiments, the arm  70  or the joint  72  may be angled from the long axis of the arm  70  to allow the platform to rotate about an arbitrary axis. Alternatively, the rotatable joint  72  may be combined with a universal joint to increase flexibility when positioning the platform  12 . It may also be recognized that some applications require only one rotatable joint, so that platform  12  has only one axis of rotation.  
         [0060]     In some embodiments, the platform  12  is connected to the arm  70  by an adjustable fastener  88 . The adjustable fastener  88  may be a bolt with a knurled head, a pin connection with a threaded end for tightening purposes, or any other element that provides a rotational pivot for rotational adjustment of the platform  12 . A friction element  90  may be placed between the arm  70  and the platform  12  to prevent rotation of the platform  12  when the adjustable fastener  88  is tightened. The friction element  90  may be a rubber washer, fiber washer, star washer, or other frictional device capable of resisting the rotation of platform  12 . Alternatively, the arm  70  may be permanently affixed to the platform  12 .  
         [0061]     While the rotatable joint  72  is particularly useful with keyboard applications, it is not limited to keyboard applications and may be used, by way of example, with other IO devices such as trackballs. In embodiments employing rotatable joint  72 , it is preferable to insure that the size of the retainer  14  is adequate to retain the IO device when the platform  12  is tilted away from a level position. As shown in  FIG. 7 , the retainer  14  is sized to accommodate a keyboard  100 .  
         [0062]      FIG. 7  also shows an alternative embodiment for controlling the rotation of fastener  18 . Flexible material  92  may be affixed to the inboard segment  76 . The fastener  18  passes through the flexible material  92  so that the frictional contact with the material prevents easy rotation of the fastener  18 . Flexible material  92  may also cushion the inboard segment  76  where it contacts the armchair stop  22  and may prevent rotation of the inboard segment  76  relative to the chair arm  24 . Flexible material  92  may be neoprene, rubber, or similar material capable of lightly gripping the shank of fastener  18 , frictionally preventing rotation of the inboard segment  76 , or cushioning the inboard segment  76 . Optionally, a friction element  94  may be placed on the shaft of fastener  18  so that it contacts armchair stop  22  when fastener  18  is tightened, as in  FIG. 2 . The friction element  94  may be a rubber washer, fiber washer, star washer, or other frictional device capable of resisting the rotation of fastener  18 .  
         [0063]     Two armchair trays may be used to support a keyboard, as shown in  FIG. 11 . In this application, a first armchair tray  110  is attached to a left chair arm  112 , and a second armchair tray  114  is attached to a right chair arm  116 . The first armchair tray  110  is configured with a platform  12  with a top surface  118  having a high coefficient of friction. The second armchair tray  114  is configured with a platform  12  having a top surface divided into two regions: a high friction region  120  and a relatively smooth region  122  adapted for use with an IO device such as a mouse. A platform with a retainer assembly, as shown in  FIGS. 9 and 10 , may be used as an alternative to a platform  12  with its surface divided into two regions. A keyboard  100  may be placed on the two armchair trays so that it rests on top surface  118  and region  120 , each of which have high coefficients of friction. Thus, keyboard  100  is supported in a manner that resists sliding off of the platforms  12 . A mouse  102  or other IO device may be placed on smooth region  122 .  
         [0064]     Platform  12  as installed on armchair tray  114  is depicted in more detail in  FIG. 12 . High friction region  120  abuts smooth region  122  along a boundary  124 . In some embodiments, the top surface of region  120  and region  122  is even along boundary  124 , meaning that there is no edge along boundary  124  presented to an IO device resting on the surface of platform  12 . In some embodiments, the top surfaces of regions  120  and  122  are coplanar. In other embodiments, the surfaces of region  120  and  122  may be at different levels.  
         [0065]     An embodiment having more fore and aft adjustability is shown in  FIGS. 13 and 14 . Fore and aft adjustability, in this context, means capable of being adjusted in distance from the chair arm to the center of platform  12 .  FIG. 13  is a bottom view of platform  12  connected to an arm  130  with a rotational fastener  132 . Rotational fastener  132  extends through slot  134  into platform  12 . Slot  134  provides fore and aft adjustability. Movable fastener  18  (not shown) may extend through hole  136  to secure arm  130  to armchair stop  22  (not shown.)  
         [0066]     Rotational fastener  132  may be tightened to prevent motion of platform  12  relative to arm  130 . Rotational fastener  132  may be a threaded nut and bolt, a pin connection with a threaded end for tightening purposes, or any other element that provides a rotational pivot for the angular adjustment of the platform  12 , while still interconnecting the platform  12  with outboard segment  78 . Rotational fastener  132  preferably includes a knurled head so that it may be tightened or loosened by hand. In some embodiments, a friction element  90  may be placed between platform  12  and outboard segment  78  to assist in controlling rotation. In an alternative embodiment shown in  FIG. 14 , a top view of arm  130 , a friction material  138  may be secured to arm  130  to prevent motion of platform  12  relative to arm  130 . Friction material  138  may include, without limitation, rubber, or neoprene. In another embodiment, the surface of arm  130  may be roughened or treated to provide a high coefficient of friction.  
         [0067]     Referring now to the embodiment shown in  FIGS. 15-16 , shown is an additional manner of connecting the platform  12  to an armchair or other piece of furniture using at least one ball and socket connection device  200  ( 200 ′). Such a ball and socket connection device  200  ( 200 ′) including a ball  202  ( 224 ,  226 ) dimensioned to fit within a socket  204  ( 204 ′) defined by a sheath  206  ( 207 ).  
         [0068]     In this embodiment of the invention (for example,  FIG. 16 ), a configuration containing two balls  202 ,  224  configured to be held in two separate sockets  204 ,  204 ′ defined within the same sheath  206  is utilized. Preferably, the connection of each of the balls  202 ,  224  within the sockets  204 ,  204 ′ is “sticky,” meaning that a sufficient frictional force exists (or is provided) between the balls  202 ,  224  and their respective sockets  204 ,  204 ′ so as to allow the position of a device or structure attached to a ball  202 ,  224  to remain set in a desired position, while still allowing movement of this ball  202 ,  224  within the socket when a preselected quantity of additional force is placed upon the ball  202 ,  224 . This concept described infra with respect to the “rotational control device.” Utilization of such a rotational control device allows significantly greater ranges of movement and variation among positions in which the various portions of the device can be arranged.  
         [0069]     In addition, the friction holding the balls  202  ( 224 ,  226 ) within the sockets  204  ( 204 ′) can be adjusted by a tensioning device  208  ( 209 ), such as the threaded bolt embodiments shown in  FIGS. 15-16 . In such an embodiment, the sleeves ( 206 ,  207 ) comprise a pair of opposing halves that the tensioning device  208  ( 209 ) can more loosely or more tightly hold together, thereby changing the amount of friction the sockets ( 204 ,  204 ′) exert on the balls ( 202 ,  224 ,  226 ).  
         [0070]     The exact configuration of the various ball and socket connection devices which are set forth in the present invention are specific in form and are dependent in large part upon the needs and necessities of the user of a particular embodiment.  
         [0071]     In the embodiments of the invention shown in  FIGS. 15-16 , the ball  202  ( 202 ′) of the connection device is connected to an attachment body or plate  210  ( 210 ′) that is connected or configured for connection with any of the other portions of another device. For instance, the ball  202  connects to the plate  210  through use of a bar  201 , the plate  210  then connecting to the underside of the platform  12  through use of plate connecting features  212 ; and the ball  202 ′ connects to the plate  210 ′ through use of a bar  201 ′, the plate  210 ′ then connecting to the side of a chair arm  24  through use of plate connecting features  212 . These plate connecting features allow these plates to be connected to any of a variety of surfaces through any of a variety of connection devices. These devices include but are not limited to devices such as screws, bolts, molds, rivets, nails, fasteners, tapes, hook-and-loop attachments, adhesives and any other device that accomplishes the purpose of connecting a plate to another object. The figures also show first end  264 , second end  266 , first joint  270 , second joint  272 , third joint  274 , fourth joint  276  and intermediate joint  278 . In the figures, the “intermediate” joint is made of the third and fourth joints.  
         [0072]     While various embodiments having two sockets are shown and described, it is to be distinctly understood that the number of sockets or combinations of sockets is not limited by this disclosure and description. In fact, combinations having three or more sockets and sheath combinations are included and contemplated within the scope of this invention and disclosure.  
         [0073]     Referring now to  FIGS. 17-18 , shown is another embodiment of a connection platform  250 . This form of platform  250  having a base  251  with a pair of balls ( 252 ,  256 ) extending there-from through use of bars/arms ( 254 ,  258 ). By utilizing a pair of balls ( 252 ,  256 ), multiple trays may extend from the same chair arm (or other structure), for instance a first tray for supporting a first end of a keyboard and a second tray for providing a surface upon which a mouse or other input device is used.  
         [0074]     It is preferred that platform  250  attach to the chair arm  24  (or other surface) in a rotational manner, such as through use of a screw (as shown in  FIGS. 17-18 ). Other rotational connection manners/fasteners are likewise possible. One benefit of a rotational attachment is that the platform(s) attached thereto can be swung (rotated) out of the way easily, for instance when a user desires to get up from his/her chair.  
         [0075]     While this embodiment shows use of two balls on the rotational attachment, it is expressly envisioned that rotational attachment could be utilized not only with single (or multiple) ball platforms, but also with non-ball embodiments of the present invention.  
         [0076]     In other embodiments of the invention, the configuration of the plate which is connected to the ball(s) may be modified for other uses. One of these configurations is shown in  FIGS. 19-20 .  FIGS. 19-20  shows an embodiment wherein an armchair, desk, table, or other piece of furniture defines a receiver  216  that is configured to receive a generally elongated extension arm  218 . The receiver  216  is preferably a slot or hole defined within the piece of furniture, such as a chair arm  24 .  
         [0077]     This extension arm  218  is connected to a ball  203  which is configured to connection with a socket  244 , defined by a sleeve  234 . As has been discussed previously, the exact configuration of the ball  203  and the socket  244  can be varied according to the needs and necessities of the user. The figures also showing first joint  280 , first end  282 , second end  284  and second joint  286 .  
         [0078]     Some embodiments of the present invention show the sheath/sleeve to be a part of, or directly connected to, any desired attachment device including platforms that contain other forms of flexible attachment devices. In some instances, additional flexibility and ease of use is provided by connecting extension arms of various lengths with various ball and socket connecting devices.  
         [0079]     In the embodiment of the invention shown in  FIGS. 19-20 , the platform of the present invention (which was previously shown in  FIG. 12 ) is combined with elements of the ball and socket combination which is described herein. In this combination ( FIGS. 19-20 ), a sleeve  234  has a first portion that defines a socket  244  that is configured for connection to a ball  203 . The second (opposite) end of the sleeve  234  is configured to connect, via a pin  236  or suitable structure, to a platform arm  130  at a flange  240 , thereby forming a pivot joint. This connection with the flange  240  allowing the platform and arm  130  attached thereto to pivot within a first plane, whereas the ball-socket attachment at the first end allows the combination to be pivoted among many planes, including but not limited to up/down and left/right. The combination of this first plane and multi-plane positioning is that the platform can easily be positioned as desired by the user.  
         [0080]     In these figures, while only a single ball and socket combination is utilized, it will be distinctly understood that the invention may be variously combined to include a variety of other features as well.  
         [0081]     Benefits of using one or more ball and socket connections in such an embodiment include the ability to be positioned in a great number of different positions in a number of different planes. Doing so allows a user maximum flexibility in the positioning of the platform.  
         [0082]     The exemplary embodiments shown in the figures and described above illustrate but do not limit the invention. It should be understood that there is no intention to limit the invention to the specific form disclosed; rather, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims. For example, while the exemplary embodiments illustrate adjustable work surfaces, the invention is not limited to use with adjustable work surfaces and may be used with other platforms. While the invention is not limited to use with adjustable work surfaces, it is expected that various embodiments of the invention will be particularly useful in such devices. Hence, the foregoing description should not be construed to limit the scope of the invention, which is defined in the following claims.  
         [0083]     While there is shown and described the present preferred embodiment of the invention, it is to be distinctly understood that this invention is not limited thereto, but may be variously embodied to practice within the scope of the following claims. From the foregoing description, it will be apparent that various changes may be made without departing from the spirit and scope of the invention as defined by the following claims.