Patent Publication Number: US-6903924-B1

Title: Computer keyboard tray

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application is a continuation-in-part application of application Ser. No. 09/738,567, filed Dec. 15, 2001, now U.S. Pat. No. 6,644,605 which claims priority from U.S. Provisional Pat. Application Ser. No. 60/172,498, filed Dec. 17, 1999, the entire disclosure of which is hereby incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   The present invention relates generally to devices for use in conjunction with a computer, and more particularly, to a polymeric computer keyboard tray and method for making the same. 
   The use of computers in both business and the home is commonplace and routine. Our reliance upon personal computers continues to increase. A large number of individuals spend a majority of their day operating a personal computer. These individuals, as well as those having a pre-existing muscular or skeletal infirmity, are prone to the development of repetitive stress injuries. Repetitive stress injuries are most often attributed to the lack of a proper ergonomic position while entering data into a computer and specifically, to the position of one&#39;s arms and hands when typing on the keyboard. There are a wide variety of repetitive stress injuries, most of which affect an individual&#39;s wrists, hands, and forearms. If a person&#39;s typing position is not corrected, these repetitive stress injuries can eventually cause muscle fatigue, swelling of the joints and tendons, and may lead to serious nerve damage. The most prevalent form of repetitive stress injury is Carpal Tunnel Syndrome, caused by compression of certain nerves in the wrist and leading to a loss of sensation in the fingers and the hands. Left untreated, Carpal Tunnel Syndrome may require surgery, and often requires medical attention resulting in discomfort and the loss of work time. 
   In response to repetitive stress injuries, the industry has advanced a variety of computer keyboard trays and wrist rests intended to support the keyboard and elevate the wrists of an individual to a proper ergonomic typing position. Many existing computer keyboard trays are formed of several independent layers, adhered to one another in order to form the keyboard tray. The use of several discrete layers in the formation of a keyboard tray increases the cost and complexity of the manufacturing process. Furthermore, over time, the layers of these keyboard trays have a tendency to shift or separate. This shifting or sliding causes the computer keyboard to move when one is typing, thereby complicating the process of using the computer. 
   An additional problem confronted by the computer industry is the use of computer keyboard trays in conjunction with computer keyboard support mechanisms. Computer keyboard support mechanisms are normally mounted on the underside of a work surface, for example a desk or table, such that it may be moved between a retracted position, where it is positioned under the work surface, and an extended position, wherein it is extended beyond the front edge of the work surface. In addition, many of these computer keyboard support mechanisms include a tilting feature, allowing the angle of the computer keyboard to be adjusted so as to enable an individual to alter the angle, or tilt, of the computer keyboard in order to achieve a comfortable typing position. Keyboard trays used in conjunction with computer keyboard support mechanisms are normally a flat sheet made of a rigid material having a perimeter composed of hard angles or surfaces. Inadvertent contact with these hard surfaces may cause injury to individuals and/or damage to equipment. Additionally, many of the keyboard trays used in conjunction with computer keyboard support mechanisms do not contain a wrist rest and thereby increase the probability that an individual using such computer keyboard support mechanism will incur some form of repetitive stress injury. 
   Therefore, there exists a need for a keyboard support tray which is economical to manufacture, rigid, and yet provides an ergonomically correct, cushioned surface for support of one&#39;s wrists while typing. 
   SUMMARY OF THE INVENTION 
   According to one aspect of the invention, a keyboard tray for use with a computer keyboard includes a tray body, that is formed from a compressible material and has a generally planar upper surface dimensioned for supporting a computer keyboard thereon. A support member, which comprises a substantially rigid material, is positioned at least partially within the body to provide reinforcement to at least a portion of the tray body. 
   In one aspect, the tray body includes a wrist rest, which are both preferably formed from the compressible material and, preferably, with the body and the wrist rest being monolithic. 
   In a further aspect, the support member is integrally molded in the tray body. Further, the support member includes a lower surface, which is substantially flush with the lower surface of the tray body. 
   In another aspect, the tray body includes a recess with the support member positioned in the recess. 
   According to yet another aspect, the tray includes a pair of arcuate channels, with alternately each channel dimensioned to receive a thigh of an operator. The tray includes a contoured lower surface configured to incline the upper planar surface when the lower surface is supported on a generally horizontal surface. 
   In another form of the invention, a keyboard tray for use with a computer keyboard and a computer keyboard support mechanism includes a tray body having an upper planar surface and an enlarged portion forming a wrist rest. The upper planar surface is dimensioned for supporting a keyboard. The tray body comprises a compressible material and includes a support member, which comprises a substantially rigid web that reinforces the tray body wherein the tray body is capable of supporting a keyboard. An attachment assembly is carried by the tray body and configured to removably mount the tray body to a computer keyboard support mechanism. 
   In one aspect, the attachment assembly is preferably mounted to the support member. 
   In yet another form of the invention, a method of making a keyboard tray includes providing a substantially rigid support member, applying a cushioning material to the support member, and forming a wrist rest with the cushioning material. For example, the cushioning material may be applied by spraying, dipping, or coating. In one aspect, the cushioning material is applied by molding. For example, the support member may be placed in a mold cavity of an injection molding apparatus, with the cushioning material injected in the mold cavity to at least partially encapsulate the support member. 
   It can be appreciated from the foregoing that the present invention provides an ergonomically pleasing keyboard tray that is easy to use and, further, that is comfortable to the user. These and other advantages and features of the present invention will be apparent to one skilled in the art, in light of the following specification when read in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a keyboard tray according to the invention, with a computer keyboard, mouse and accessory device illustrated in phantom; 
       FIG. 2  is a bottom perspective view of the keyboard tray depicted in  FIG. 1 ; 
       FIG. 3  is a sectional view taken along lines III—III of  FIG. 1 ; 
       FIG. 4  is an exploded, cross-sectional view of the keyboard tray of  FIGS. 1 and 2 , depicting attachment to a computer keyboard support mechanism with the computer keyboard depicted in phantom; 
       FIG. 5  is a plan view of a support member according to the invention; 
       FIG. 6  is a detailed plan view depicting the cable way of the present invention; 
       FIG. 7  is a detailed, plan view depicting a cable way according to an alternative preferred embodiment; 
       FIG. 8  is a cross-sectional view depicting a curved support member according to an alternative preferred embodiment; 
       FIG. 9  is a sectional view depicting the raised section of the support member; 
       FIG. 10  is a sectional view depicting an injection mold and the support member of the keyboard tray; 
       FIG. 11  is a sectional view of the injection mold of  FIG. 10 , tilted at a first angle and a second angle; 
       FIG. 12  is a front view of a keyboard tray according to an alternative preferred embodiment of the present invention; 
       FIG. 13  is a sectional side view of a keyboard tray according to another alternative preferred embodiment; 
       FIG. 14  is a perspective view of a keyboard tray according to still another alternative preferred embodiment, with the computer keyboard illustrated in phantom; 
       FIG. 15  is a bottom perspective view of the keyboard tray of  FIG. 14 ; 
       FIG. 16  is a plan view of the support member for the keyboard tray of  FIGS. 14 and 15 ; 
       FIG. 17  is an exploded perspective view of a keyboard tray according to still another alternative preferred embodiment; 
       FIG. 18  is a perspective view of the support member for the keyboard tray of  FIG. 17 ; 
       FIG. 19  is a front view of the keyboard tray of  FIG. 17 , with the adjustable wrist rest assembly depicted in the raised position; 
       FIG. 20  is the same view as  FIG. 19 , with the adjustable wrist rest assembly depicted in the lowered position; 
       FIG. 21  is an exploded perspective view of a keyboard tray with an adjustable mouse pad assembly according to another alternative preferred embodiment; 
       FIG. 22  is a bottom view of the keyboard receiving member of  FIG. 21 ; 
       FIG. 23  is a rear view of the keyboard receiving member of  FIGS. 21 and 22 ; 
       FIG. 24  is a side sectional view of the keyboard tray of  FIG. 21 ; 
       FIG. 25  is a front view of the keyboard tray of  FIG. 21 ; 
       FIG. 26  is a bottom view of a keyboard tray according to still another alternative preferred embodiment; 
       FIG. 27  is a side view of a cam member, illustrated attached to a support member and positioned within a keyboard receiving member, both depicted in cross-section; 
       FIG. 28  is a bottom view of the cam member of  FIG. 27 ; 
       FIG. 29  is a detailed view of a securing member for the keyboard tray depicted in  FIG. 26  with the friction member and arm depicted in cross-section; 
       FIG. 30  is a top view of the securing member of  FIG. 29 ; 
       FIG. 31  is a sectional view of an injection mold for the manufacture of the keyboard tray depicted in  FIGS. 21 and 26 ; 
       FIG. 32  is a detailed view depicting an electromagnetic attachment assembly according to the invention; 
       FIG. 33  is a cross-section view of yet another embodiment of the keyboard tray of the present invention; 
       FIG. 34  is an enlarged fragmentary view of the keyboard tray of  FIG. 33 ; 
       FIG. 35  is a top plan view of another embodiment of the keyboard tray of the present invention; and 
       FIG. 36  is a cross-section taken along line XXXVI—XXXVI of FIG.  35 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention provides a keyboard tray and method for making the same, formed of a single polymeric material, and including a support member integrally molded within the interior of the keyboard tray. The support member of the present invention provides adequate rigidity and prevents the keyboard tray from flexing, enabling the keyboard tray to be used in conjunction with computer keyboard support mechanisms commonly used in both business and home environments. The keyboard tray of the present invention is economical to manufacture, and results in an aesthetically attractive device having sufficient cushioning to provide a comfortable typing surface and minimize the probability of contracting a repetitive stress injury. 
   Referring now to the  FIG. 1 through 10 , a computer keyboard tray  10 , according to the present invention, includes a keyboard receiving member  20  having a top  21 , a pair of opposing sides  26  and  28 , a front  34 , and a back  38 . Sides  26  and  28 , and front  34  are curved outwardly, with sides  26 , and  28  preferably having a greater angle of curvature than front  34 . Alternatively, sides  26 ,  28  and front  34  are linear. Top  21  is a generally planar surface. 
   In another preferred form, as shown in  FIG. 14 , sides  26 , and  28 , and back  38  define a generally half circle shape. Also, preferably, sides  26 ,  28  and back  38  are curved or tapered inwardly towards bottom  30 , as shown most clearly in FIG.  3 . The inwardly curved surfaces from top  21  to bottom  30  of sides  26 ,  28  and back  38  provide a sleek, aesthetic appearance. Extending from front region  21 ′ of top  21  is a wrist rest  46 . In one preferred embodiment, wrist rest  46  and keyboard receiving member  20  are monolithic, i.e., unitary in construction, and formed of a foamed polymeric material. Any polymeric material having sufficient durability, and density may be used. Preferably, the polymeric material used in the manufacture of keyboard tray  10  is foamed polyurethane. Integrally molded within interior  25  of keyboard receiving member  20  is a support member  70 . 
   The length of keyboard tray  10 , defined as the distance between sides  26  and  28 , in one preferred form, is long enough to support a standard, or extended size, computer keyboard  200  thereupon with sufficient distance remaining from edge  202  or  204  of computer keyboard  200  and sides  26  or  28  of keyboard receiving member  20 , respectively, to thereby permit the placement and operation of a computer peripheral device, such as for example, a mouse  210 . As can be seen in  FIG. 1 , the length of keyboard tray  10  is sufficient to enable the user to place mouse  210  adjacent side  26 , or side  28  depending upon the computer operators preference. 
   Wrist rest  46 , extending above the plane defined by top  21  of keyboard receiving member  20 , is sized to extend substantially the length of keyboard tray  10 , and terminate proximate to sides  26  and  28 . The length of wrist rest  46  allows a computer operator to support their wrists upon wrist rest  46  while entering data into computer keyboard  200 , and while operating mouse  210 . Wrist rest  46  may be formed having any height and width desired, so as to provide an ergonomically correct support for one&#39;s wrists. As depicted most clearly in  FIGS. 4 and 8 , wrist rest  46  preferably has a outwardly curved top surface  48 . Curved top surface  48  creates a comfortable support upon which an operator&#39;s wrists are placed. Wrist rest  46  is formed having a substantially vertical inner surface  50 , abutting edge  203  of computer keyboard  200 , or positioned in proximity thereto. Vertical inner surface  50  of wrist rest  46  provides a barrier, or straight surface, against which computer keyboard  200  may be properly positioned. In addition, vertical inner surface  50  prevents keyboard  200  and/or mouse  210  from being inadvertently removed from top  21  of keyboard receiving member  20  during operation and prevents computer keyboard  200  from sliding when placed at an angle. The density of wrist rest  46  may be either less than or substantially equal to the density of keyboard receiving member  20 . Wrist rest  46  is preferably slightly compressible so that upon placement of one&#39;s wrists upon outer surface  48 , wrist rest  46  deforms slightly, but maintains the proper ergonomic wrist position. Upon removal of one&#39;s wrists, wrist rest  46  returns to its normal, non-compressed position. Wrist rest  46  may be solid in construction, or may have an internal channel as will be discussed below. 
   A rim  54  projects upwardly, beyond the horizontal plane defined by top  21 , from opposing sides  26 ,  28  and back  38  of keyboard receiving member  20 . Rim  54  has an arcuate outer surface and also provides a barrier, preventing mouse  210  from falling off top  21  of keyboard receiving member  20  during operation, and especially when keyboard tray  10  is placed at an angle. 
   At least one cable way  60  is formed in keyboard receiving member  20 . Cable way  60  is positioned along back  38  and proximate to a side  26 , or  28 . Preferably, there are two cable ways  60 , each of which is proximate to a side  26 , or  28 , with one removably accepting the electrical cable  212  of mouse  210 , and the other, electrical cable  205  of computer keyboard  200 . Removably securing electrical cable  212  of mouse  210  to keyboard tray  10  facilitates the orientation of mouse  210  and manages the length of electrical cable  212  so as to permit optimal movement of mouse  210  upon keyboard receiving member  20 . Furthermore, cable ways  60  prevent mouse  210 , and computer keyboard  200 , from being inadvertently detached from keyboard tray  10  in the event contact is made with electrical cable  205  and/or  212 . 
   With reference to  FIG. 6 , in one preferred form, cable ways  60  each include a vertical cutout section  62  formed in back  38  of keyboard receiving member  20 , and a pair of inwardly tapered flanges  64  which together enclose cutout section  62 . To insert electrical cable  205  or  212  within cutout section  62  of a cable way  60 , a slight force is used to urge electrical cable  205  or  212  beyond flanges  64  and seat the cable within cutout section  62 . Flanges  64  provide resistance to the removal of electrical cable  205  or  212  from cutout section  62  in the event inadvertent contact is made with electrical cable  205  or  212 . 
   In an alternative preferred form, as shown in  FIG. 7 , each cable way  60 ′ has a generally keyhole slot shape with a generally linear slot  66 , and a circular seating section  68 . The walls  67  defining slot  66  are positioned a preselected distance apart, such that there is frictional engagement between walls  67  and electrical cable  205  or  212 , while seating section  68  is preferably circular and has a wider area relative to slot  66 . Thus, when one inserts electrical cable  205  or  212  through cable way  60 ′, frictional resistance is experienced as electrical cable  205  or  212  is urged through slot  66 , and is forwarded to seating section  68 . Further, this frictional resistance acts as a barrier, preventing the inadvertent removal of electrical cable  205  or  212  from cable way  60 ′. 
   Positioned proximate to side  26  and back  38  are a pair of throughholes  39  which together define an accessory support assembly. Throughholes  39  are dimensioned to removably receive support posts  222  of a computer accessory device  220 . As depicted in  FIG. 1 , computer accessory device  220  is illustrated as a document stand configured to support a document in a substantially vertical position, and hence, allows a computer operator to read therefrom in a facile manner. Although the accessory support assembly is described as supporting a document stand, it will be recognized by those with ordinary skill in the art that the accessory support assembly may be used to support other computer accessories without departing from the spirit and scope of the present invention. 
   As shown in  FIG. 9 , support member  70  may be formed with a pair of regions  71 , each of which surrounds throughhole  39  in keyboard receiving member  20 , and is formed having a greater height than the remainder of support member  70 . Each region  71  also includes a throughhole  73  in registry with throughhole  39 . Furthermore, a pair of inwardly extending lips  78 , formed within support member  70  extend within throughholes  73 . Lips  78  of support member  70  provide a frictional barrier which must be overcome during insertion and removal of support posts  222  from throughholes  39  and  73 . Overcoming this slight frictional force aids in the securement of support post  222  within keyboard tray  10 . Additionally, the increased height of regions  71  of support member  70  provides additional resistance to horizontal forces, and thereby securely supports accessory device  220  in keyboard tray  10 . 
   Support member  70  is generally rigid, and integrally formed within the interior  25  of keyboard tray  10  during the molding process, as will be discussed below. Preferably, support member  70  is substantially linear and has a length less than the distance between sides  26  and  28 , and a width less than the distance between back  38  and front  34  so that the perimeter of keyboard receiving member  20  and at least a portion of wrist rest  46  are not supported by support member  70 . That is, sides  26 ,  28 , back  38 , and wrist rest  46  are cantilevered from support member  70 . The dimensions of support member  70  enables sides  26 ,  28 , and back  38  to be slightly softer and more flexible than the remainder of keyboard tray  10  and provides a greater cushioning effect in the event contact is made between keyboard tray  10  and an individual or surrounding equipment. The absence of support member  70  within at least a portion of wrist rest  46  permits wrist rest  46  to flex slightly about a horizontal plane when one&#39;s wrists are placed thereupon, permitting a more comfortable typing position. Moreover, the dimensions of support member  70  result in a lighter keyboard tray  10 , without sacrificing necessary strength and rigidity. Alternatively, as shown in  FIG. 8 , support member  70  may have a width sufficient to support wrist rest  46 , and is provided with a curved section  72  proximate to front  34  to increase the rigidity of wrist rest  46 . Support member  70  is preferably positioned with interior  25  of keyboard receiving member  20  such that it is approximately the same distance from top  21  and bottom  30 . 
   Support member  70  may be any material commonly utilized in the art capable of providing sufficient rigidity to keyboard tray  10 . Non-limiting examples of materials suitable for use as support member  70  include metals, metal alloys, wood or wood composites, and polymeric materials. Preferably, support member  70  is formed of polyurethane. Most preferably, support member  70  is a composite wood board. 
   As shown in  FIG. 5 , in one preferred form, support member  70  is formed having a plurality of ribs  74  extending from top surface  71 ′. Ribs  74  extend in a radial pattern from the central region  76  of support member  70 , and impart additional rigidity upon support member  70 , preventing flexing of support member  70 , and thus increases the strength of keyboard tray  10 . Additionally, a rim  76 ′ extends from the perimeter of support member  70  to further increase rigidity. It will be recognized by those with ordinary skill in the art that although only top surface  71 ′ is shown having ribs  74  and rim  76 ′, it is within the spirit and scope of the present invention to include ribs  74  and rim  76 ′ on the bottom surface of support member  70 . Furthermore, it will be understood that alternate rib patterns may be substituted for the radial pattern depicted in  FIG. 5 , without departing from the spirit and scope of the invention. 
   Bottom  30  of keyboard receiving member  20  includes an attachment assembly  80  depending therefrom (FIG.  2 ). Attachment assembly  80  includes a pair of spaced side members  82  extending in a direction substantially perpendicular to back  38 , and terminating proximate to back  38 . Ends  82 ′ of side members  82  are joined by a bridge member  86  running generally perpendicular to side members  82 . Side members  82  and bridge member  86  collectively define a contact surface  88  in bottom surface  30  of keyboard receiving member  20 . Contact surface  88  is sized to abuttingly contact a platform  132  of a conventional computer keyboard support mechanism  134  (FIG.  4 ), normally movably attached to the underside of a work surface (not shown). Furthermore, inner surfaces  83  of side members  82  and inner surface  87  of bridge member  86  define a wall to prohibit movement of platform  132  of computer keyboard support mechanism  134  from contact surface  88 . Attachment assembly  80  further includes at least one, and preferably four, fastener receiving members  90  positioned in throughholes  92  formed in contact surface  88 . Fastener receiving members  90  are fixedly attached to bottom surface  77  of support member  70 , by any mechanical means or adhesive commonly utilized in the industry. Fastener receiving members  90  may be any receiving members commonly utilized in the art dimensioned to securingly receive fasteners  92 ′ positioned through apertures  135  of platform  132 . For example purposes only, fastener receiving members  90  may be circular bosses having a threaded channel, while fasteners  92 ′ are bolts dimensioned for receipt by the circular bosses. 
   Alternatively, a shown in  FIG. 15 , an attachment assembly  80 ′ includes one or more fastener receiving members  90 ′ fixedly attached to support member  70  and extending through keyboard receiving member  20  via throughholes  92 . Fastener receiving members  90 ′ are of the same construction as fastener receiving members  90 , and are fixedly attached to bottom surface  77 . 
   To secure keyboard tray  10  to computer keyboard support mechanism  134 , keyboard tray  10  is first placed upon platform  132  such that platform  132  abuttingly contacts bottom surface  30  of keyboard receiving member  20 . Thereafter, fasteners  92 ′ are placed through apertures  135  and secured within fastener receiving members  90  or  90 ′ to thereby anchor keyboard tray  10  to platform  132  of computer keyboard support mechanism  134 . 
   As shown in  FIGS. 2 ,  4 ,  8 , and  15 , bottom  30  of keyboard receiving member  20  includes a channel  97  proximate to front  34  and extending substantially the length between sides  26 ,  28 . Channel  97  may be generally linear or express an angle of curvature approximately equal to the angle of curvature of front  34 . Channel  97  provides a grasping surface, permitting an operator to move the keyboard tray  10  and computer keyboard mechanism  134  between an extended and a retracted position. 
   In one preferred form, as shown in  FIG. 14 , keyboard receiving member  20  of keyboard  10  is sized such that the distance between the apex  39  of back  38  and vertical inner surface  50  of wrist rest  46  is sufficient to enable the placement of a standard, or extended size, computer keyboard  200 , with sufficient distance remaining from edge  203  of computer keyboard  200  and apex  39  of back  38  such that a region  102  is formed therebetween. Region  102  of keyboard receiving member  20  is formed with one or more channels  104  spanning generally parallel to wrist rest  46 , and dimensioned to receive pens, pencils, erasers, and the like. In addition, region  102  is formed with on or more depressions or indentations  106 . Indentations  106  are preferably circularly shaped, and are sized to permit the placement of paper clips, binder clips and the like therein. Preferably, as shown in  FIG. 16 , support member  70  is formed having holes  108  which correspond to indentations  106  during the molding process to provide greater depth to indentations  106  and a softer surface. Also shown in  FIG. 16 , are cutout regions  109  which correspond to the molding regions of cable ways  60 ,  60 ′. 
   Turning now to  FIG. 10 , there is shown an injection mold  110  having sections  112  and  114 . To form keyboard tray  10 , injection mold  110  is oriented so that section  114 , having inner surface  115 , corresponding to the top  21  of keyboard receiving member  20  and the exterior surface of wrist rest  46 , positioned below section  112 . Support member  70  is then heated to a pre-selected temperature prior to introduction within injection mold  110 . Pre-heating support member  70  before injecting polymeric material within injection mold  110  improves the material flow characteristics of the polymer contacting support member  70 , resulting in a keyboard tray having a uniform density and increasing the bond between the polymer and support member  70 . A suitable release agent is then applied to interior surface  113 ,  115  of sections  112 ,  114 , respectively. The release agent utilized can be any release agent normally utilized in the art, and is preferably paraffin based. Thereafter, the interior surface of injection mold  110  is optionally coated with an in-mold paint coat to vary the surface color of keyboard tray  10 . Once the optional in-mold paint coat is in place within injection mold  10 , support member  70  is placed within the interior  111  of injection mold  110 , and held therein at a preselected distance from both inner surface  113  of section  112  and inner surface  115  of section  114  by fasteners  116 , such as, for example, bolts. Fasteners  116  are threaded through section  112  of injection mold  110 , via holes  118 , and secured to fastener receiving members  90  attached to bottom surface  77  of support member  70 . Once support member  70  is secured within interior  111  of injection mold  110 , the mold is sealed and the polymeric material utilized to form keyboard tray  10  is injected within interior  111  through an injection port  120 . Once an adequate charge of polymeric material is injected within injection mold  110 , it is subjected to a preselected temperature and pressure schedule in order to produce a foamed polymeric keyboard tray. 
   As shown in  FIGS. 5 ,  16 , and  18 , the support member is formed with a central hole  75  and one or more off-center or flow through holes  79 . When support member  70  is secured within interior  11  of injection mold  10 , central hole  75  is positioned in registration with injection port  118 . Placing central hole  75  of support member  70  in registration with injection port  118  permits polymeric material to flow through support member  70  and towards inner surface  115  of section  114  of injection mold  110  to thereby increase the speed at which interior  111  is filled with polymeric material. Off-center holes  79  provide additional flow through regions through which the polymer may flow, thereby reducing the time necessary to fill interior  111 , and hence, reduces the time required to mold keyboard tray  10 . While not wishing to bound by theory, it is believed that providing central hole  75  and off-center holes  79  in support member  70  promotes uniform density in the resultant keyboard tray  10 . Off-center holes  79  may be of any size and pattern, as demonstrated by the various sizes and patterns of  FIGS. 5 ,  16 , and  18 . 
   As shown in  FIG. 11 , injection mold  110  is preferably positioned at a preselected angle α off the horizontal such that edge  120  of section  114  is positioned in a plane below edge  122  of section  114 . Tilting injection mold  10  at a preselected angle α off the horizontal facilitates injection of polymeric material within interior  111  by utilizing the gravitational effect. Additional, the tilt angle α of injection mold  110  results in the movement of air trapped within mold  110  upwards from mold section  114  to mold section  112 , where it is exhausted by one or more air exhaust ports  124 . As inner surface  115  of mold section  114  corresponds to top  21  of keyboard receiving member  20  and the exterior surface of wrist rest  46 , tilting injection mold  110  at angle α results in the migration of air away from inner surface  115 , and thus reduces the occurrence of surface defects in top  21  and wrist rest  46 . The tilting of injection mold  110  also reduces the occurrence of density gradients as a result of trapped air within the interior of keyboard tray  10 . Angle α is between approximately 1° and 10°, preferably between approximately 4° and 7°, and most preferably between approximately 5° and 6°. 
   Injection mold  110  is preferably placed at a tilted position such that mold  110  is oriented to assume angle α, and a second tilt angle β. Angle β is defined as the angle at which edge  123  of mold section  114  deviates from the horizontal. That is, edge  120  is positioned in a plane below edge  123 . Angle β is preferably between approximately 1° and 10°, more preferably between approximately 4° and 7°, and most preferably between approximately 5° to 6°. The tilting of mold  110  at both angle α and β maximizes the evacuation of air from mold  110  during the manufacturing process of computer keyboard tray  10  and minimizes the occurrence of air pockets, increases the uniform density of the resulting keyboard  10  and decreases the occurrence of surface defects in top  21  and wrist rest  46 , Also, the increased fluid pressure imparted upon section  114  is believed to result in the formation of a stronger, uniform density, wrist rest which aids in the avoidance of repetitive stress injures. 
   When keyboard tray  10  is formed with cable ways  60  or  60 ′, section  112  is formed with one or more exhaust ports positioned in proximity to the molding region in which a cable way  60 ,  60 ′ is formed. The presence of these exhaust ports proximate to the molding region of cable ways  60 ,  60 ′ increase the quality of the mold about the region as the curvaceous surface of cable ways  60 ,  60 ′ may potentially trap air, and thus reduce the uniformity of the resultant keyboard tray. 
   Turning now to  FIG. 12 , according to an alternative preferred embodiment, a keyboard tray  10   a  is formed having two arcuate or concave channels  120  in bottom  30  of keyboard receiving member  20 . Arcuate channels  120  extend from front  34  to back  38  of keyboard receiving member  20 , and are each dimensioned to receive a thigh of a computer operator, and hence permits keyboard tray  10   a  to be supported upon one&#39;s lap. In all other aspects, keyboard tray  10   a  is structurally similar to keyboard tray  10  except for the absence of attachment assembly  80 ,  80 ′. 
   With reference to  FIG. 13 , a computer keyboard  10   b  includes a contoured bottom surface  127  so that keyboard receiving member  20  is at a positive inclination from front  34  to back  38 , relative to surface  129 . The angulation of keyboard tray  10   b  results in the inclination of the computer keyboard at a comfortable typing angle. In all other aspects, keyboard tray  10   b  is structurally similar to computer keyboard tray  10  except for the absence of attachment assembly  80 ,  80 ′. 
   Referring now to  FIGS. 17 through 20 , in another preferred embodiment, a keyboard tray  10   c  includes a keyboard receiving member  130  having a front  132 , an opposing back  134 , and a pair of opposing sides  136  and  138 , and is dimensioned to receive a standard or extended size keyboard  200 . Keyboard receiving member  130  is formed with an attachment assembly  80  or  80 ′ to permit attachment of keyboard receiving member  130  to computer keyboard support mechanism  134 . Keyboard receiving member  130  is essentially planar while a support member  140 , depicted in  FIG. 18 , is positioned within its interior. Support member  140  is formed with a generally planar first member  142 , which is substantially parallel to top  131  of keyboard receiving member  130  when positioned within its interior, and includes a front edge  143 . A pair of cutouts  142 ′ are formed in rear surface  142 ″ and correspond to the molding area for cable ways  60 ,  60 ′. A ledge  144  depends from front edge  143  of support member  140  and is generally orthogonal thereto. Ledge  144  includes at least one, and preferably, a pair of throughholes  145  through which fasteners  146 ,  146 ′ such as, for example, bolts, are positioned. 
   Support member  140  is integrally molded within the interior of keyboard receiving member  130  with ledge  144  depending toward bottom  139  and in proximity to, and substantially parallel with, front  132 . Fasteners  146 ,  146 ′ extend through front  132  of keyboard receiving member  130  and provide securing sites for the removable attachment of an adjustable wrist rest assembly  150  to keyboard receiving member  130 . 
   Adjustable wrist rest assembly  150  is provided with a wrist rest  151  formed of a polymeric material, preferably a foamed polymeric material, and is fixedly attached to support section  154  of an attachment member  152  by any means commonly employed in the art. Preferably, wrist rest  151  is attached to top surface  153  by an adhesive. Support section  154  is generally parallel to bottom  139 . Depending from edge  154 ′ of support section  154  is a ledge  156 . Ledge  156  spans the length of support section  154  and is generally orthogonal thereto. An attachment plate  158  extends from the central section of ledge  156  and is configured to receive an attachment assembly  160 . Attachment plate  158  includes a pair of generally vertical slots  162  and  164 , each of which is proximate to an edge  158 ′,  158 ″, respectively. Positioned between slots  162 ,  164  are three spaced pins  165   a ,  165   b ,  165   c  projecting substantially orthogonal from surface  159  of attachment plate  158 . 
   Attachment assembly  160  includes a pair of arms  168  and  169  and a locking member  175 . Each arm  168 ,  169  is formed with three throughholes  172   a ,  172   b ,  172   c , and includes two sections  174  and  176  which meet at an angle. To assemble attachment assembly  160  to attachment plate  158  of adjustable wrist rest assembly  150 , attachment member  152  is placed in proximity to front  132  of keyboard receiving member  130  so that slots  162  and  164  are aligned with fasteners  146 ,  146 ′ projecting from front  132 . Thereafter, attachment plate  158  is moved such that fasteners  146 ,  146 ′ extend through slots  162 ,  164 . Arms  168  and  169  are then placed in position with fastener  146  extending through throughhole  172   a  of arm  168  while throughholes  172   b  and  172   c  of arm  168  receive pins  165   a  and  165   b , respectively. Arm  169  is juxtaposed with relation to arm  168 , with pin  165   b  and  165   c  extending through throughholes  172   c  and  172   b  of arm  169 , respectively. Fastener  146 ′ also extends through throughhole  170   a  of arm  169 . Once arms  168  and  169  are in position, fastener  146 ′ extending through slot  164  and arm  169  is fitted with a nut and washer assembly  173  to thereby secure arm  169  in place. Fastener  146 , extending through slot  162  and arm  168 , has attached at its free end locking member  175 . Locking member  175  is formed with an internally threaded channel dimensioned to receive fastener  146 . Once arms  168 ,  169  and locking member  175  are in position, a pair of spring members  177  and  178 , each of which has a curved end  180 , are placed about the outer periphery of pin  165   b , with their free ends extending slightly beyond and supported by the top surface of pin  165   a  and  165   c , respectively. After spring members  177 ,  178  are in position, a securing member  182  is placed over pin  165   b  to hold arms  168 ,  169  and spring member  177 ,  178  in place, while a cover  179  ( FIG. 17 ) is placed over attachment plate  158  and attachment assembly  160  leaving only locking member  175  exposed. Cover  179  includes a side cut out  179 ′ to permit movement of arm  168 , and is adhesively attached to attachment plate  158  by applying a suitable adhesive about perimeter  179 ″. Cover plate  179  protects a user from injury by preventing contact with the components of attachment assembly  160 , and prevents unauthorized tampering therewith. Preferably, cover  179  is made of polyurethane. 
   To adjust adjustable wrist rest assembly  150 , once it is attached to keyboard receiving member  130 , handle  175 ′ of locking member  175  is rotated in a particular direction to loosen adjustable wrist rest  150 . A slight force is placed upon adjustable wrist rest assembly  150  in either the upward or downward vertical direction to alter the position of wrist rest  151  relative to top  131  of keyboard receiving member  130 . Application of a vertical force on adjustable wrist rest assembly  150  moves the same along slots  162 ,  164 , with pin  165   a  acting as a pivot point for arm  168 , and pin  165   c  for arm  169 . Once adjustable wrist rest assembly  150  is placed in the desired position, handle  175 ′ of locking member  175  is rotated to secure adjustable wrist rest assembly  150  in position. 
   Adjustable wrist rest assembly  150  is shown in the raised position in  FIG. 20 , while  FIG. 19  depicts adjustable wrist rest assembly  150  in the lowered position. As adjustable wrist rest assembly  150  is moved between the raised position and the lowered position, spring members  177 ,  178  provide a biasing force to retard the movement of adjustable wrist rest assembly  150  as it is moved from the raised position to the lowered position. The retardation of movement of adjustable wrist rest assembly  150  prevents the damage caused by the forcible contact between the ends of slots  162 ,  164  and fasteners  146 ,  146 ′ when adjustable wrist rest assembly  150  is moved from the raised position to the lowered position. 
   With reference to  FIGS. 21 through 25 , a keyboard tray  10   d , according to a preferred alternative embodiment, includes a keyboard receiving member  250  having a wrist rest  252  extending from front region  254  of top  256 . Wrist rest  252  is formed having an internal channel  253  positioned within interior  252 ′ (FIG.  24 ). Internal channel  253  runs generally from end-to-end of wrist rest  252  and is sealed by the polymer comprising wrist rest  252 . Alternatively, wrist rest  252  may have the same solid foamed polymer construction as wrist rest  46 . Positioned with interior  258  of keyboard receiving member  250  is a support member  260 . Keyboard receiving member  250  includes a pair of opposing sides  262  and  264  and a back  266 . Each opposing side  262 ,  264  has an arcuate cutout region  268 . Each arcuate cutout section  268  has substantially the same angle of curvature as the mouse pad  284  of an adjustable mouse pad assembly  270 . Projecting from top  256 , along back  266  and opposing sides  262  and  264  is a rim  272 . Seen most clearly in  FIGS. 21 and 23 , rim  272 , extending from back  266 , has a central section  274  having an increased height with respect to the adjacent sections of rim  272  along back  266 . Back  266  includes a pair of cable ways  273 . Each cable way  273  includes a generally keyhole shaped slot  275  similar to that depicted in FIG.  7 . In addition, cable ways  273  include a horizontal slot  276  formed in back  266  and in registration with keyhole slot  275 . Cable ways  273  enable a cable to be inserted within the seating end of keyhole shaped slot  275  and placed within the generally horizontal slot  276  formed in back  266  of keyboard receiving member  250 . 
   Bottom  257  of keyboard receiving member  250  includes a C-shaped grasping channel  278  positioned proximate to front  255 . In addition, proximate to each side  262 ′,  264  is a grasping channel  280 , each of which is formed generally orthogonal to back  266 . C-shaped grasping channel  278  and grasping channels  280  provide a variety of grasping surfaces to enable an individual to grasp the underside of keyboard receiving member  250  and move the same when used in conjunction with a computer keyboard support mechanism  134 . As depicted in  FIG. 22 , keyboard receiving member  250  is formed with an attachment assembly  80 ′, enabling keyboard receiving member  250  to be used in conjunction with a computer keyboard support mechanism  134 . However, it will be recognized by those with ordinary skill in the art, that attachment assembly  80  may be formed in keyboard receiving member  250 . 
   A track  282  is positioned within bottom  257  and is generally perpendicular to ends  278 ′ of C-shaped grasping channel  280 . Track  282  is generally T-shaped in cross section and is adhesively attached about its exterior surface to the wall formed by a channel or cutout  283  within bottom surface  257  (FIG.  24 ). Track  282  is formed of a low friction material such as, for example, a suitable polymer, metal or metal alloy. 
   Adjustable mouse pad assembly  270  includes a generally circular mouse pad  284  formed with a peripheral rim  285  extending from top  286 , a generally keyhole slot shaped cable way  287  and a wrist rest  288 . Mouse pad  284  may contain a support member within its interior similar to support member  70 , or may be formed completely of a polymeric material. 
   Bottom  284 ′ of pad  284  is attached to a mouse pad adjustment assembly  290 . Mouse pad adjustment assembly  290  includes a plate  292  fixedly attached to bottom surface  284 ′ of mouse pad  284 , and a first pivot member  294  attached to and depending from plate  292 . Pivot member  294  is secured within throughhole  293  of a generally linear arm  296 . End  296 ′ of arm  296  is secured to a second pivot member  298  which is dimensioned for receipt within track  282  of keyboard receiving member  250 . Pivot members  294  and  298  may be any pivot members normally encountered in the art capable of enabling adjustable mouse pad assembly  270  to pivot about a first generally vertical pivot point  295  and a second generally vertical pivot point  299 , respectively. Non-limiting examples of pivot members  294  and  298  include, but are not limited to, ball and socket assemblies and swivel joint assemblies. 
   In operation, adjustable mouse pad assembly  270  may be placed on the left or right side of keyboard receiving member  250  as the operator desires. This is accomplished by rotating or pivoting adjustable mouse pad assembly  270  about pivot member  298  until mouse pad  284  is positioned beyond front  255  of keyboard receiving member  250 . Thereafter, the operator applies a slight horizontal force to mouse pad  284  so that pivot member  298  slides within track  282 , between ends  282 ,  282 ′. Once pivot member  298  is positioned proximate to the desired side  262 ,  264 , mouse pad  284  is again rotated about pivot member  298  to thereby rotate mouse pad  284  into abutting contact with arcuate cutout section  268  formed on side  262 , or  264 . Once adjustable mouse pad  284  is in position against arcuate cutout section  268 , the operator may rotate mouse pad  284  about pivot member  294  to thereby adjust the position of wrist rest  288  to the desire of the operator. 
   In an alternative preferred embodiment, as shown in  FIGS. 26 through 30 , track  282  is replaced with a pair generally cylindrical of cam members  320 , each of which is fixedly attached to support member  260 , and project toward bottom  257  of keyboard receiving member  250 , with surface  322  of each cam member  320  being generally co-planar with bottom  257 . Each cam member  320  is positioned proximate to a side  262 ,  264  and is provided with pair of slots  324 . Each slot  324  includes a vertical section  326  formed generally parallel to surface  322  and a substantially horizontal channel  328  formed generally parallel to surface  322 . Each horizontal channel  328  terminates at a preselected N from the center line  333  shown in FIG.  28 . Preferably angle N is approximately 15°. Also, in this embodiment, bottom  257  is provided with one generally C-shaped grasping channel  259  formed proximate to front  255  and opposing sides  262 ,  264 . In this embodiment, adjustable mouse pad assembly  270 ′ is similar to adjustable mouse pad assembly  270  except that pivot member  298  is replaced with a securing member  330  fixedly attached to, and extending from end  296 ′ of arm  296 . Securing member  330  is generally cylindrical and is dimensioned for receipt by central channel  323  of cam members  320 . Securing member  330  includes a pair of pins  332  positioned in proximity to top  334 . Pins  332  are substantially axially aligned, extend in opposite directions, and are dimensioned for receipt by slots  324 . A friction member  336 , such as for example, a nylon ring, is attached to the outer periphery of securing member  330 . Additionally, pivot member  294  is positioned on support plate  292  such that pivot member  294  is offset with respect to the center of mouse pad  284 . 
   In operation, when an operator seeks to position mouse pad  284  proximate to either side  262 ,  242 , securing member  330  is placed into contact with a cam member  320  with pins  332  entering slots  324 . Once pins  332  engage horizontal sections  328 , a slight rotational force is applied to urge pins  332  along horizontal sections  328  until abutting contact is made with ends  328 . Thereafter, an operator may rotate mouse pad  284 , about pivot member  294 , to alter the position of wrist rest  288 . Inadvertent detachment of mouse pad  284  from keyboard receiving member  250  is prevented by friction member  336  frictionally engaging surface  322  of cam member  320  during rotation of securing member  330 . Thus, friction member  336  will retard movement of pins  332  along slots  324  in the event a person or equipment accidentally contacts mouse pad  284 . In addition, offsetting pivot member  294  from the center of mouse pad  284  enables an operator to rotate wrist rest  288  into the desired use position without having to rotate securing member  330  within cam member  320  and thereby accidentally disengage mouse pad  284  from keyboard receiving member  250 . To disengage mouse pad assembly  270 ′ from keyboard receiving member  250 , mouse pad assembly  270 ′ is rotated to move pins  332  toward vertical sections  326 . Thereafter, mouse pad assembly  270 ′ is pulled downward to remove pins  332  from slots  324 . 
   With reference to  FIGS. 31 and 32 , in order to manufacture keyboard receiving member  250 , of keyboard tray  10   d , support member  260  is first inserted in the injection mold  300 , having at least two sections  304  and  306 . To maintain support member  260  in the proper position during molding, section  302  of injection mold  300  is formed with one or more magnetic contact assemblies  310 . Each magnetic contact assembly  310  includes an electromagnet  312  positioned within a channel  314  formed in section  302 . Electromagnet  312  is attached to a power source (not shown) via wires  314 . A threaded, magnetic contact adapter  314  is rotatably inserted within fastener receiving members  90 , which are fixedly attached to surface  260 ′ of support member  260  and form part of attachment assembly  80 ,  80 ′. Alternatively, electromagnet  312  is brought into direct contact with fastener receiving members  90 , and/or cam members  320 . If less than four magnetic contact assemblies  310  are used, appropriate fasteners are inserted in holes  305  of section  302  of injection mold  300  and attached to fasteners receiving members  90 . Electromagnetic contact assemblies  310  provide secure support for support member  260  within injection mold  300 , and reduce processing time by enabling electromagnets  312  to be de-energized to release the resultant keyboard tray  10   d  from the injection mold subsequent to processing. 
   If wrist rest  252  is formed having internal channel  253 , as depicted in  FIG. 24 , a paraffin based strip of material  316  is attached to surface  260 ″ of support member  260 , substantially parallel to front edge  261 . Paraffin based strip of material  316  may be attached to surface  260 ′ by any means commonly utilized in the art. Preferably support member  260  is preheated as discussed above so that paraffin-based strip of material  316  thermally adheres to surface  260 ′. Once support member  260  and strip of material  316  are in position, the processing takes place largely in conformance with the method detailed above with respect to keyboard tray  10 . During the molding process, the temperature within injection mold results in the liquification of the paraffin based material and thus produces internal channel  253  within wrist rest  252 . Subsequent to removal from the mold, but prior to the temperature at which the paraffin base material solidifies, a small needle is inserted within wrist rest  252  and the liquid wax material is extracted from wrist rest  252 , resulting in the formation of internal channel  253 . It will be understood by those with ordinary skill in the art, as detailed above, that injection mold  300  may be also tilted at an angle α and a second angle β. Also, if keyboard receiving member  250  is to be formed with a track  282 , an appropriate mold section is provided within section  304 , while if keyboard receiving member  250  is to be formed with cam members  320 , section  304  includes a pair of molding sections. As illustrated in  FIG. 31 , section  304  includes a raised surface  307  projecting from interior surface  306  for the formation of cutout  283  which provides a receptacle for track  282 . Any paraffin based material having a melting temperature within the processing temperatures necessary to form keyboard tray  10   d  may be used. Non-limiting examples of paraffin material suitable for use with this invention include those manufactured by Kindt-Collins Company of Cleveland, Ohio. 
   Referring to  FIG. 33 , the numeral  410  generally designates another embodiment of the keyboard tray of the present invention. In the illustrated embodiment, keyboard tray  410  is of similar construction to keyboard  10  and includes a tray body with a planar upper surface that defines a keyboard receiving member  420 , which is defined between a pair of opposing sides, a front  434 , and a back  438 , and a wrist rest  446 . Keyboard receiving member  420  is dimensioned to at least support a computer keyboard. Optionally, keyboard receiving member  420  may be dimensioned to also provide a working surface for a mouse. 
   In the illustrated embodiment, wrist rest  446  preferably has an outwardly curved top surface  448  similar to wrist rest  46 . However, it can be appreciated that wrist rest  446  may be formed having a variety of heights and widths and shapes to provide a range of ergonomically correct supports for a user&#39;s wrists. As in the case of the previous embodiments, wrist rest  446  and keyboard receiving member  420  may be monolithic, i.e., unitary in construction, and are preferably formed from a cushioning material, such as a foamed polymeric material. For further details of suitable materials for the wrist rest  446  and keyboard receiving member  420 , reference is made to the previous embodiments. 
   Tray  410  also includes a support member  470  at least partially formed or embedded in keyboard receiving member  420 . For example, support member  470  may be molded with tray  410  wherein support member  470  is integrally formed with wrist rest  446  and keyboard receiving member  420  and at least partially encapsulated in tray  410 . Support member  470  is formed from a relatively rigid material to provide rigidity to tray  410  to prevent the keyboard tray from flexing, enabling the keyboard tray to support a keyboard and to be used in conjunction with computer keyboard support mechanisms commonly used in both business and home environments. Support member  470  comprises a generally flat member, which may be reinforced with ribs or the like as shown in  FIG. 5 , and as noted-above, may be formed or embedded in keyboard tray  410 , for example, during the molding process of the tray, similar to the previous embodiments. For further details of suitable configurations of support member  470 , reference is made to the previous embodiments. 
   Alternately, support member  470  may be post-attached to the tray after tray  410  is molded. For example, support member  470  may be adhered to a lower surface of tray  410  using an adhesive and/or may be inserted into a recess  410   a , which is formed in the lower or under surface  410   b  of tray  410  during molding, with a compression or friction fit and/or an adhesive. Recess  410   a  may include retaining lip  410   c  ( FIG. 34 ) formed about the perimeter of the recess so that when support member  470  is inserted into the recess, the material forming the tray will stretch to permit support member  470  to be inserted in recess  410   a  but will at least substantially resume to its pre-inserted configuration after support member  470  is located within recess  410 a with the lip compressed and generating a spring force to at least frictionally hold support member  470  in place in recess  410   a.    
   It should be understood that tray  410  may be molded with other structures for retaining support member  470  in recess  410   a . For example, recess  410   a  may include one or projecting structures or fingers with bulbous ends that cooperate with openings formed in support member  470  to releasably engage support member  470  in recess  410   a . By providing openings that are smaller than the bulbous ends of the projecting structures or fingers, the bulbous ends will compress when inserted into the openings thus providing a friction fit between the projecting structures and the support member. Alternately, the openings may include a stepped profile with a smaller diameter portion in which the bulbous ends are compressed and a larger diameter portion where the bulbous end(s) are permitted to expand, e.g. to approximately resume their original diameter, to provide a positive interlocking of support member  470  and tray  410 . In this manner, the support member may be removed for repair, replacement, or substitution with another support member that provides a different configuration so that tray  410  can be used, for example as a lap tray with one support member or a desk mounted tray with another support member. 
   In the illustrated embodiment, support member  470  comprises a web or plate member which has a substantially linear configuration with a generally planar lower surface  470   a . When positioned in tray  410 , support member  470  spans or extends between the sides of tray  410  and between back  438  and front  434 . Though illustrated with a lower surface  470   a  that is generally flush with the lower surface  410   b  of tray  410 , it should be understood that support member  470  may include at least portions that project below lower surface  410   a  or may be recessed within tray  410  in recess  410   a  (as shown in phantom in FIG.  33 ). Optionally, support member  470  may terminate before the sides, back  438 , or front  434  so that the sides and front and back of keyboard receiving member  420  and at least a portion of wrist rest  446  are not supported on support member  470 . That is—the sides, back  438 , front  434  and/or wrist rest  446  may be cantilevered from support member  470 . In this manner, the front and back and sides have greater flexibility than the reinforced portions of tray  410  to provide increased comfort to the user of tray  410 . However, it should be understood that support member  470  may extend, such as illustrated in  FIG. 13 , at least partially into wrist rest  446  or may extend to front  434  to provide a mounting surface for a separately formed wrist rest, such as illustrated FIG.  17 . 
   Examples of materials suitable for use as support member  470  include metals, such as steel, wood, and polymeric materials, or composite materials, such as metal reinforced woods or reinforced polymeric materials, or the like. Preferably, support member  470  is formed from a light-weight but substantially rigid material, such as polyurethane or a composite wood board, for example a wood board reinforced with a metal insert or backing member. 
   Although previously described as a web or plate member having a generally linear configuration, support member  470  may have a varying cross-section and, for example, may be molded or formed with an undulating base or lower surface ( 470   b ) dimensioned to receive the thighs of a computer operator, hence permitting keyboard tray  410  to be supported upon a user&#39;s lap. Furthermore, the under surface  470   a  of support member  470  may be molded or provided with a layer of a cushioning material  470   c , such as the material forming tray  410 , to provide additional comfort to the user of the tray when the tray is supported on the lap of the user. For example, support member  470  may be coated, sprayed, or dipped with the cushioning material. Alternately, the cushioning material may be molded on support member  470  using an injection molding machine and, further, may be molded during the support member forming process, such as in a two-shot molding process. Where support member  470  is formed, for example, from a metal or wood material, including a composite wood material, support member  470  may be placed in a molding machine, with the cushioning material injected into the mold cavity of the molding apparatus at least on one side of the support member. In addition, the cushioning material may be adhered to the support member  470  using an adhesive, for example in a press molding operation where the cushioning material is a preformed member that is adhered to the support member using pressure and/or heat in combination with an adhesive, which is applied to the support member before the support member is placed in the molding apparatus. 
   Alternately, support member  470  may include a contoured or sloped lower surface  470   d , similar to surface  127  of the tray of the previous embodiment, so that keyboard receiving member  420  is oriented with a positive inclination from front  434  to back  438 . 
   In addition, though described as being inserted or positioned in a recess formed on the lower or bottom surface of the tray, the recess may be located on an upper or top surface of the tray, with the support member providing at least a portion of the keyboard receiving member. In this application, the upper surface of the support member may be coated, sprayed, or dipped to provide a cushioning surface. Further, as described below, the support may extend from the upper surface of the tray to the lower surface of the tray with the cushioning material extending around the periphery of the support member. 
   Referring to  FIGS. 35 and 36 , tray  410 ′, which is of similar construction to tray  410 , may include a support member  470 ′ that is positioned so as to present both its lower surface  470   a ′ and its upper surface  470   b ′ generally flush with the upper surface of the tray body  412 ′. However, it can be appreciated that either or both lower and upper surfaces  470   a ′,  470   b ′ may project above or be recessed in the respective surface of the tray. In this manner, the upper surface of support member  470 ′ forms at least a portion of the keyboard receiving member  420 ′. In addition, the cushioning material extends around the periphery of the support member, with at least a portion of the front  434 ′ enlarged to form a wrist rest  446 ′. Though it should be understood that a separate wrist rest may be provided. It should be understood that either upper or lower surface  470   b ′ or  470   a ′ of support member  470 ′ may be coated, sprayed, dipped or otherwise provided with a cushioning surface using, for example, the cushioning material forming the tray body. Further, support member  470  may have extended portions that extend laterally into the cushioning material to provide an anchoring surface or anchoring members. For further details of optional materials for support member  470 ′ and the tray body, reference is made to the previous embodiments. Similarly, reference is made to the previous embodiments for examples of support member configurations and additional accessories that can be mounted to tray  410 ′. 
   It should be understood that the features of each of the embodiments of the computer keyboard tray of the present invention as described may be interchanged. Also, other changes and modifications in the specifically described embodiments can be carried out without departing from the principals of the invention, which is intended to be limited only by the scope of the appended claims, as interpreted according to the principals of patent law, including the doctrine of equivalents. For example, the support member may be formed into a skeletal shape of the tray, with the cushioning material sprayed, dipped, or otherwise coated or applied onto the support member, with the support member imparting the shape to the tray. 
   In addition, the support member may incorporate an adjustment mechanism to provide vertical adjustment of the tray relative, for example, to the lap of a user. For example, the support member may be made from two or more members with the adjustment mechanism moving one of the members relative to the other to increase or decrease the space between the members and, thereby, raise or lower the tray.