Abstract:
An adjustable desk platform can include: an upper platform defining a substantially planar work surface; a base located beneath the upper platform, the base defining a bottom surface without legs that is adapted to sit on an existing desk; first and second sets of arms coupling the upper platform to the base, wherein the first and second sets of arms are adapted for movement of the upper platform substantially in parallel with the base between a fully raised position and a fully lowered position; and a user-operable locking mechanism associated with the upper platform, the locking mechanism adapted to releasably lock the upper platform in the fully raised position, and in at least one intermediate position between the fully raised position and the fully lowered position. Other features and embodiments are discussed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of applicant&#39;s co-pending U.S. application Ser. No. 14/183,052, filed on Feb. 18, 2014, which is a continuation-in-part of applicant&#39;s co-pending U.S. application Ser. No. 14/013,285, filed on Aug. 29, 2013, which is a continuation-in-part of applicant&#39;s U.S. application Ser. No. 13/642,651, filed on Oct. 22, 2012, which in turn is the national stage of International Application No. PCT/US2012/48775, filed on Jul. 30, 2012, which in turn claims the priority of U.S. Provisional Application No. 61/651,101, filed on May 24, 2012. The entire contents of the foregoing applications are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This application relates generally to ergonomic workplace environments, and more particularly, to an adjustable desk platform or desk. 
     BACKGROUND 
     Sitting for long periods of time during the work day is generally not good for one&#39;s health and wellness. Medical studies show that sitting increases the rate of all-cause mortality, especially from cardiovascular disease, diabetes and obesity, for example. People who sit for most of the day are 50 percent more likely to die of heart attacks. Even if you exercise, the longer you sit the greater the chances you will die. Sitting shuts down the circulation of the fat-absorbing enzyme lipase, while standing up engages muscles and promotes the distribution of lipase, which prompts the body to process fat and cholesterol, independent of the amount of time spent exercising. 
     There are desks available to be used while standing, and even desks adapted for use while a user is on a treadmill. However, standing for very long periods of time to work is more tiring, dramatically increases the risks of carotid atherosclerosis because of the additional load on the circulatory system, and increases the risks of varicose veins. 
     Taking regular breaks from sitting for prolonged periods of time can have several positive outcomes. For example, standing can provide more energy during the work day. In addition, because standing burns more calories than sitting, standing can also result in weight loss without changes in diet or exercise. It is also harder to become more tired or lose focus when standing. 
     Because regular breaks from sitting are beneficial, and because many people during the work day want to remain productive while taking breaks from sitting, and because everyone will sit and stand for different lengths of time at different times during the day, there exists a need to create a work environment that is ergonomic for someone standing as well as sitting, and allows the transition to be easy, quick, and simple. 
     SUMMARY 
     According to embodiments, an adjustable desk platform can include: an upper platform defining a substantially planar work surface; a base located beneath the upper platform, the base defining a bottom surface without legs that is adapted to sit on an existing desk; first and second sets of arms coupling the upper platform to the base, wherein the first and second sets of arms are adapted for movement of the upper platform substantially in parallel with the base between a fully raised position and a fully lowered position; and a user-operable locking mechanism associated with the upper platform, the locking mechanism adapted to releasably lock the upper platform in the fully raised position, and in at least one intermediate position between the fully raised position and the fully lowered position. 
     According to another embodiment, the adjustable desk platform can include: an upper platform defining a substantially planar work surface; a base located beneath the upper platform, the base defining a bottom surface without legs that is adapted to sit on an existing desk; and first and second sets of arms coupling the upper platform to the base, wherein the first and second sets of arms are adapted for movement of the upper platform substantially in parallel with the base between a fully raised position and a fully lowered position; wherein the upper platform moves laterally with respect to the base when moved from the fully lowered position to the fully raised position, and the base includes a counterweight adapted to offset weight of the upper platform when in the raised position. 
     According to another embodiment, the adjustable desk platform can include: an upper platform defining a substantially planar work surface; a base located beneath the upper platform, the base defining a bottom surface without legs that is adapted to sit on an existing desk; first and second sets of arms coupling the upper platform to the base, wherein the first and second sets of arms are adapted for movement of the upper platform substantially in parallel with the base between a fully raised position and a fully lowered position; and a biasing mechanism associated with at least one of the first and second sets of arms, wherein moving the upper platform toward the fully raised position loads the biasing mechanism. 
     According to another embodiment, the adjustable desk platform can include: an upper platform defining a substantially planar work surface, the upper platform having first and second hand apertures extending therethrough; a base located beneath the upper platform, the base defining a bottom surface without legs that is adapted to sit on an existing desk; first and second sets of arms coupling the upper platform to the base, wherein the first and second sets of arms are adapted for movement of the upper platform substantially in parallel with the base between a fully raised position and a fully lowered position; and first and second user-operable locking mechanisms associated with the upper platform, each of the first and second locking mechanisms adapted to releasably lock the upper platform in the fully raised position, wherein the first and second locking mechanism each include a user operable handle mounted to an underside of the upper platform substantially adjacent to one of the hand apertures. 
     Other features and advantages will become apparent from the following description, taken in connection with the accompanying drawings, wherein, by way of illustration and example, embodiments of the invention are disclosed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and advantages of the invention will be apparent from the following description, as illustrated in the accompanying drawings wherein like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. 
         FIG. 1  is a perspective view of an embodiment of an adjustable desk platform. 
         FIG. 2  is another perspective view of the adjustable desk platform of  FIG. 1 . 
         FIG. 3  is a side view of the adjustable desk platform of  FIG. 1 . 
         FIG. 4  is front view of the adjustable desk platform of  FIG. 1 . 
         FIG. 5  is perspective view of parts of an embodiment of a locking mechanism of the adjustable desk platform of  FIG. 1 . 
         FIG. 6  is an exploded view of the locking mechanism of  FIG. 5 . 
         FIG. 7  is a perspective view of an embodiment of a biasing mechanism of the adjustable desk platform of  FIG. 1 . 
         FIG. 8  is a side view of an embodiment of the locking mechanism of the adjustable desk platform of  FIG. 1 , showing the handle in the locked position. 
         FIG. 9  is a side view of the locking mechanism of  FIG. 8  showing the handle in the un-locked position. 
         FIG. 10  is a side view of the adjustable desk platform of  FIG. 1  showing an example of directional movement of the upper platform relative to the lower platform and the pivot arms. 
         FIG. 11  is a side view of an embodiment of the biasing mechanism. 
         FIG. 12  is a perspective view of an embodiment of the adjustable desk platform, showing the tray. 
         FIG. 13  is a bottom view of an embodiment of the adjustable desk platform showing the tray and counter weights. 
         FIG. 14  is a perspective view of an embodiment of the adjustable desk platform including a keyboard tray. 
         FIG. 15  is an enlarged, perspective view of the pivot arms of an embodiment of the adjustable desk platform. 
         FIG. 16  is a perspective view of an embodiment of the adjustable desk platform including legs. 
         FIG. 17  is a partially exploded, perspective view of the adjustable desk platform with legs of  FIG. 16 . 
         FIG. 18  is a perspective view of another embodiment of the adjustable desk platform, shown in a fully lowered position. 
         FIG. 19  is a perspective view of the adjustable desk platform of  FIG. 18 , shown in a fully raised position. 
         FIG. 20  is a side view of the adjustable desk platform of  FIG. 18 , shown in the fully lowered position. 
         FIG. 21  is a side view of the adjustable desk platform of  FIG. 18 , shown in the fully raised position. 
         FIG. 22  is a partially-exploded, perspective view of another embodiment of the adjustable desk platform, shown in a partially raised position. 
         FIG. 23  is a partially-exploded, side view of the adjustable desk platform of  FIG. 22 , shown in the partially raised position. 
         FIG. 24  is a partially-exploded, rear view of the adjustable desk platform of  FIG. 22 , shown in the partially raised position. 
         FIG. 25  is a side view of another embodiment of the adjustable desk platform as seen from a user standing behind the desk platform, with the desk in a partially raised position. The user&#39;s hands are shown resting on the locking mechanism. 
         FIG. 26  is similar to  FIG. 25 , but shows the user&#39;s hands moving the locking mechanism. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the invention are discussed in detail below. In describing embodiments, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. While specific embodiments are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations can be used without departing from the spirit and scope of the invention. 
     Embodiments of the adjustable desk platform described herein can transition between a lower operating position and an upper operating position quickly, easily, and simply. This may be useful, for example, to provide height adjustability to conventional, fixed desktop workspaces. Alternatively, embodiments of the adjustable desk platform can include their own support legs. 
     Referring to  FIGS. 1 to 4 , the adjustable desk platform can generally include an upper platform  10 , a lower platform  20 , and left and right pivot arm sets  30 , which can connect the upper platform  10  and lower platform  20 . According to embodiments, the upper platform  10  and/or the lower platform  20  can include a substantially planar top surface that can serve as a working surface for the user, for example, to support reading materials, papers, computers, other electronic devices, and the like. The adjustable desk platform can include one or more locking mechanisms  40 , for example, one associated with each of the left and right pivot arm sets  30 . The adjustable desk platform can also include one or more biasing mechanisms  50  (see  FIG. 3 ), for example, each associated with the left and right pivot arm sets  30 . The adjustable desk platform can also include a reinforcement member  60 , visible in  FIGS. 2 and 4 . 
     Referring to  FIG. 2  and  FIGS. 4 to 6 , lower mounting brackets  11  can be located on upper platform  10 , for example, secured thereto, or formed integrally therewith. As shown in the figures, two lower mounting brackets  11  can be secured to the underside of the upper platform  10  at opposite sides of the upper platform  10 . As shown in  FIGS. 2  to  FIG. 4 , lower platform  20  is located below the upper platform  10 , and the pivot arm sets selectively adjust the height of the upper platform  10  with respect the lower platform  20 , for example, with the upper platform  10  and the lower platform  20  remaining substantially parallel to one another during movement. 
     Lower platform  20  can include two upper mounting brackets  21 , for example, one located near each side of the lower platform  20 . The upper mounting brackets can be formed integrally with the lower platform  20 , or alternatively, can be secured thereto using fasteners or other means known in the art. Lower platform  20  can also include one or more counter weights  22 , and a housing  23  near each upper mounting bracket  21 . 
     Referring to  FIGS. 1 and 2 , the upper mounting brackets  21  can be located on the top surface of the lower platform  20 , for example, at opposite sides thereof, and the lower mounting brackets  11  can be located on the bottom surface of the upper platform  10 , for example, in registry with the upper mounting brackets  21 . Each upper mounting bracket  21  can include an arc slot  211 , shown in  FIGS. 1 and 3 . One of the housings  23  can be located adjacent the outer side of each of the upper mounting brackets  21 . As shown in  FIG. 2 , one or more counter weight(s)  22  can be located on the bottom surface of lower platform  20 . 
     As shown in  FIGS. 3 and 5 , each pivot arm set  30  is connected to the respective lower mounting bracket  11  on the upper platform  10  and to the respective upper mounting bracket  21  on the lower platform  20 . As shown, each pivot arm set  30  can include a main pivot arm  31  and secondary pivot arm  32 . The pivot arms  31 ,  32  can be pivotably connected to the lower mounting bracket  11  at one end, and to upper mounting bracket  21  at the other end using, for example, rivets, fasteners, or other structures known in the art. The main pivot arm  31  and secondary pivot arm  32  can be connected to the lower mounting bracket  11  and upper mounting bracket  21  at different locations, as shown in the figures. The pivot arm sets  30  can be connected to the upper mounting bracket  21  at the opposite side of the respective housing  23 . For example, the pivot arm sets  30  can connect to the interior side of the upper mounting brackets  21 , while the housings  23  can connect to the exterior sides of the upper mounting brackets  21 . 
     Referring to  FIGS. 5 and 6 , the upper end of each primary pivot arm  31  can include a locking part  311  including a plurality of perforations  3111 . The plurality of perforations  3111  can include at least one perforation that is selectively movable into alignment with a hole  111  in the respective lower mounting bracket  11 . Referring to  FIGS. 3 and 7 , each secondary pivot arm  32  can include a boss  321  that slides within the arc slot  211  of the respective upper mounting bracket  21 . 
     Referring to  FIGS. 2 ,  4 , and  8 , one or more locking sets  40  can be located on the bottom of the upper platform  10 . For example, each locking set  40  can be fixed on the respective lower mounting bracket  11 , however other locations are possible. Referring to  FIG. 6 , each locking set  42  can include anchors  41 . Each anchor  41  can selectively engage one of the perforations  3111  of locking part  311 , and can also engage through the hole  111  of lower mounting bracket  11 , thereby fixing the main pivot arm  31  in position with respect to the respective lower mounting bracket  11 . Furthermore, as shown in  FIGS. 5 and 8 , each locking set  40  can include a handle  42  and a linkage mechanism  43 . 
     Referring to  FIGS. 5 ,  6 , and  8 , each linkage set  43  can include a first linkage  431 , a second linkage  432 , and a third linkage  433 , which, according to an embodiment, are pivotably connected to one another in sequence. Each first linkage  431  can be located underneath the bottom of the upper platform  10 , and can have a pivot joint with handle  42 . Each third linkage  433  can be connected with the respective anchor  41 , for example, by rivets, pins, or other structures extending through the third linkage  433  and anchor(s)  41  as shown in  FIGS. 9 and 10 . Each locking set  40  can contain a spring  44 , adapting piece  45 , and housing  46 . Each adapting piece  45  of locking set  40  can be secured on the bottom of upper platform  10 , and can include a pivot joint with second linkage  432 . One end of spring  44  can be connected with adapting piece  45  and the other end of spring  44  can be connected with second linkage  432  in proximity to the first linkage  431 . Each locking set  40  can include a housing  46  that can cover at least the second linkage  432 , third linkage  433 , spring  44 , adapting piece  45 , and anchor  41 . The housing  46  can be connected to the underside of the upper platform  10 . 
     As shown in  FIGS. 3 and 7 , each biasing mechanism  50  can be located on lower platform  20 , and can be connected with pivot arm sets  30  to assist the upper platform  10  in raising/lowering with respect to the lower platform  20 . Each biasing mechanism  50  can include a spring  51 , a support  52 , a booster spring  53 , and a pivot point  54 . One side of spring  51  can be connected with the support  52  and the other side can form a pivot joint with the secondary arm  32 , for example, by attaching to the boss  321 . Each support  52  and booster spring  53  of biasing mechanism  50  can be connected with lower platform  20 . Arc slot  211  can be selectively connected with the respective secondary pivot arm  32  on the other side of the respective upper mounting bracket  21 . Pivot point  54  can be located against the bottom side of booster spring  53 . Each biasing mechanism  50  can be located between the respective upper mounting bracket  21  and housing  23 , thereby concealing the biasing mechanism  50 . 
     As shown in  FIG. 4 , reinforcement member  60  may extend between the left and right pivot arm sets  30 . According to an embodiment, reinforcement member may include a supporting rod  61  and a separate reinforcement  62 , however, other single-member and multi-member embodiments are possible. According to an embodiment, supporting rod  61  can be connected with the primary pivot arm  31  of each pivot arm set  30 , and reinforcement  62  can be connected with the secondary pivot arm  32  of each pivot arm set  30 . According to embodiments, the reinforcement member can fix the side-to-side distance between the pivot arms and add stability, avoiding side-to-side movement when lifting or lowering upper platform  10  from lower platform  20 , and can make the adjustable platform operate smoothly. 
     When in use, the user can place the adjustable desk platform on to a desktop, and may place items on the upper platform  10  as desired, such as, without limitation, a computer, documents, desk lamps, instruments, and supplies. The user can adjust the height between the upper platform  10  and the lower platform  20  according to their working posture and/or other needs. 
       FIG. 3  depicts the adjustable desk platform in a fully raised position. Referring to  FIGS. 3 ,  8 - 10 , and  12 , in order to lower the adjustable desk platform, the user can pull handle  42 , which in turn displaces the first linkage  431 , second linkage  432 , and third linkage  433 . This can, in turn, retract the anchor  41  and cause the anchor to withdrawal from the perforation(s)  3111  of the primary pivot arm  31 . As a result, the pivot arm  31  is released from a substantially fixed position, allowing primary pivot arm  31  and secondary pivot arm  32  to move, consequently allowing the upper platform  10  to move with respect to the lower platform  20 . Accordingly, the distance between upper platform  10  and lower platform  20  can be reduced, for example, to the fully lowered position shown in  FIG. 11 , or to some position between the fully raised position and the fully lowered position. This allows the distance between the upper platform  10  and lower platform  20  to be easily set and adjusted. 
     As shown In FIGS.  3  and  8 - 11 , when the user moves the upper platform  10  and lower platform  20  to a desired height relative to each other, the user can release the handle(s) of locking set(s)  40 . As a result, the retraction force of springs  44  of each locking set  40  can move the second linkage  432 , causing first linkage  431  and third linkage  433  to move sequentially, thereby causing anchors  41  to lock through the hole  111  of the lower mounting bracket and the corresponding perforations  3111  on primary pivot arm  31 . This, in turn, locks the position of the upper platform  10  relative to the lower platform  20 . 
     As shown in  FIGS. 3 ,  10 , and  11 , as the primary and secondary pivot arms  31 ,  32  pivot with respect to the respective upper mounting bracket  21 , the boss  321  slides within arc slot  211  of the upper mounting bracket  21 , and accordingly, stretches or relaxes the compression spring  51  of the corresponding biasing mechanism  50 . Referring to  FIG. 11 , since pivot point  54  leans against the bottom side of booster spring  53 , when upper platform  10  and lower platform  20  are moved toward the fully lowered position, boss  321  can press laterally against the booster springs  53 , thereby causing booster spring  53  to bend. Thus, in embodiments, the booster springs  53  can provide additional upward bias when the upper platform  10  is in or near the fully lowered position. 
     As shown in  FIGS. 3 ,  8 ,  9 , when the user desires to increase the distance between the lower platform  20  and the upper platform  10 , the user can pull the handle(s) of the locking set(s)  40  to impact locking set  40 , springs  44 , and anchors  41 , causing anchors  41  to retract from the perforation  3111  and hole  111 , releasing the primary and secondary pivot arms  31 ,  32  so the spacing between the upper platform  10  and the lower platform  20  can be increased. 
     As shown in  FIGS. 3 ,  10 , and  11 , lowering the upper platform  10  causes the pivot arm sets  30  to pivot with respect to the upper mounting brackets  21 . The resultant rotation of the secondary pivot arms  32  causes the respective bosses  321  to slide within the respective arc slots  211 , thereby stretching the respective compression springs  51  of the biasing mechanisms  50 , providing a measure of resistance against lowering of the upper platform  10 . When the distance between the upper platform  10  and the lower platform  20  is gradually increased from the fully lowered position, bosses  321  slowly pull away from the respective booster springs  53 , and allows the booster springs  53  to retract to their natural, unbent state. 
     Increasing the weight on upper platform  10  (e.g., by placing an item on the upper platform  10 ) can increase the difficulty of raising the upper platform  10  from the lower platform  20 . Due to the configuration of the biasing mechanism  50 , booster spring  53 , and pivot point  54 , when upper platform  10  is raised from the lower platform  20 , the elastic force of booster spring  53  and spring  51  can influence the boss  321  of each secondary pivot arm  32 , causing secondary pivot arm  32  to generate an upward lifting force, reducing the amount of effort required from the user to raise the upper platform  10 . 
     When lifting upper platform  10 , the overall center of gravity of the adjustable desk platform can shift between lower platform  20  and upper platform  10 , especially when various items are placed on top of upper platform  10 . Because items located on the upper platform create additional weight, the overall center of gravity of the adjustable desk platform will quickly shift to the upper platform  10 , and potentially make the adjustable desk platform unstable. Accordingly, the counterweight(s)  22  can increase the weight of lower platform  20 , thereby helping to counterbalance the weight of the upper platform  10  when in the raised position and/or when weighted with items. 
     According to embodiments, the housings  23  of upper platform  10  and the housings  46  of locking set  40  can help protect the user&#39;s fingers or other foreign matter from being caught in the locking sets  40 , the pivot arm sets  30 , and/or inside of the biasing mechanisms  50 . Housings  23  and housings  46  can also add to the aesthetic appearance of the adjustable desk platform. 
     Referring to  FIGS. 1 and 2 , the adjustable desk platform can include a keyboard tray  70 . The keyboard tray  70  can be detachably connected with lower platform  20 . Keyboard tray  70  includes a tray portion  71  and one or more releasable joint component(s)  72 . According to an embodiment, two joint components  72  can be connected on opposed sides of tray portion  71 . The joint components  72  can be slidably mounted on the lower platform  20 . Additionally or alternatively, the joint components  72  can be drilled in the housing  23  of lower platform  20 . The joint components are not limited to the embodiments shown, and other connectors known in the art can be used as alternatives. 
     When desired, the keyboard tray  70  can be attached to lower platform  20 , and items can be placed on it, such as a keyboard. According to embodiments, tray  70  can be located at an adjustable distance from the lower platform  20 . 
     Referring to an alternative embodiment shown in  FIG. 14 , the keyboard tray  70 A can be attached to the bottom side of the upper platform  10 . For example, a joint component  72 A can connect the tray portion  71 A to the underside of the lower platform  10 . When in use, keyboard tray  70 A may move up and down with upper platform  10 , thereby making it more convenient to access items placed on keyboard tray  70 , such as a keyboard. 
     Referring to  FIG. 15 , the main pivot arm  31  and/or secondary pivot arm  32  can be cladded with a protector  80 . According to an embodiment, the protector  80  is made with EVA foam (ethylene-vinyl acetate copolymer), however other materials are possible. Protector  80  can help prevent jammed fingers due to an operator reaching between pivot arm sets  30  and upper mounting brackets  21 . 
     Referring to  FIGS. 16 and 17 , embodiments of the adjustable desk platform can include legs that support the adjustable desk platform above the ground. For example, the adjustable desk platform can include four legs  90  extending from its corners, as shown, however, more or less than four legs are possible. The legs  90  can be fixed in length, or alternatively, can be adjustable in length using structures known in the art. For example, according to embodiments, the legs may telescope to adjust their length. For example, as shown in  FIG. 16 , each leg  90  can include a first portion  90 A and a second portion  90 B that telescopes within the first portion  90 A to adjust the leg length. Conventional structures can be utilized to lock the position of the second portion  90 B with respect to the first portion  90 A. One of ordinary skill in the art will understand based on this disclosure that other configurations of telescoping legs  90  can be provided. Moreover, one of ordinary skill in the art will understand based on this disclosure that other configuration of legs besides telescoping legs can be used to provide adjustable leg lengths. 
     The legs  90 , whether fixed or adjustable in length, can allow the adjustable desk platform to be self-supported above the ground. Casters, rollers, wheels, or other structures (not shown) can be provided at the bottom of the legs  90  to facilitate movement of the adjustable desk platform. Except for the provision of legs and the related structures, embodiments of the adjustable desk platform shown in  FIGS. 16 and 17  can be substantially the same as described in connection with  FIGS. 1-15 . 
     Referring to  FIG. 17 , the adjustable desk platform can include a frame member  91  that attaches, for example, to the upper mounting brackets  21 , lower platform (not shown), or other part of the adjustable desk platform. For example, fasteners such as bolts or rivets, welding, bonding, or other attachment techniques can be used. The legs  90  can in turn be attached to the frame member  91 , for example, using fasteners such as bolts or rivets, welding, bonding, or other attachment techniques. As shown in  FIG. 17 , an embodiment can include end caps  92  that extend into open ends of the frame member  91 , however, other configurations are possible. Referring back to  FIG. 16 , embodiments can include a cover portion  93  that extends over and conceals all or a portion of the frame member  91 , thereby improving the safety and/or appearance of the adjustable desk platform. Although not shown, lateral supports can extend between one more pairs of the legs  90 . 
     Referring to  FIGS. 18-21 , another embodiment of the adjustable desk platform is shown. The embodiment of  FIGS. 18-21  is substantially the same as shown and described in connection with  FIGS. 1-15 . For example, the adjustable desk platform of  FIGS. 18-21  can include the same or similar pivot arm sets  30 , locking set(s)  40 , biasing mechanism(s)  50 , reinforcement member(s)  60 , counterweight, legs, and/or other features of previously-described embodiments. Accordingly, only additions or differences from previous embodiments are described below. 
     Generally similar to the embodiment of  FIG. 14 , the adjustable desk platform of  FIGS. 18-21  can include a keyboard tray  70 A suspended below the upper platform  10 . The keyboard tray  70 A can be adapted to support a computer keyboard, mouse, tablet computer, or other device. For example, the keyboard tray  70 A can be substantially planar, and can have a size equal to, or greater than, a conventional computer keyboard. According to an embodiment, the surface area of the keyboard tray  70 A is between about one half and about one quarter of the surface area of the upper platform. According to an embodiment, the surface area of the keyboard tray  70 A is about one third of the surface area of the upper platform  10 . In order to provide sufficient space for the keyboard tray  70 A, according to embodiments, the pivot arm sets  30  can be lengthened as compared to embodiments without the keyboard tray, for example, to increase distance between the upper platform  10  and lower platform  20 . For example, the pivot arms sets  30  may be increased lengthwise by between about 2″ and about 5″ as compared to embodiments without the tray, more specifically, by about 3″ to about 4″. 
     As best seen in  FIGS. 18 and 19 , the keyboard tray  70 A can be generally “T”-shaped, in that it can define a relatively narrow portion  100  joined to a relatively wide portion  102  to define a “T” shape. The narrow portion  100  and wide portion  102  are shown separated by an imaginary dashed line in  FIG. 18  for illustration purposes only. The edge of the upper platform  10  adjacent the keyboard tray  70 A can also define a recess  104 , such as a generally “U” shaped recess. The width of the recess  104  can be the same or similar to the width of the narrow portion  100  of the keyboard tray  70 A. As a result, the narrow portion  100  of the keyboard tray  70 A can be positioned generally in registry with the recess  104 , for example, for ergonomic reasons. 
     Referring to  FIGS. 18 and 21 , first and second support members  106 ,  108  can connect the keyboard tray  70 A to the upper platform  10 . According to embodiments, the first and second support members  106 ,  108  can be located adjacent opposite sides of the generally U-shaped recess  104 . Additionally or alternatively, the first and second support members  106 ,  108  can be located adjacent opposite ends of the narrow portion  100  of the T-shaped keyboard tray  70 A. According to this embodiment, the narrow portion  100  of the keyboard tray  70 A can fit the keyboard, and the wide portion  102  of the keyboard tray  70 A can provide additional support for the user&#39;s hands or wrists, however, other uses are possible. One of ordinary skill in the art will understand based on this disclosure that the upper platform  10  and keyboard tray  70 A are not limited to the specific shapes and appearances shown in  FIGS. 18-21 . 
     Still referring to  FIGS. 18 and 21 , the support members  106 ,  108  can comprise metal brackets, such as stamped metal brackets, that are connected to the keyboard tray  70 A and to the upper platform  10  on opposite ends, for example, using fasteners such as screws, nails, rivets, or bonding or other techniques known in the art. Alternatively, all or a part of the support members  106 ,  108  can be integral (e.g., monolithic) with the upper platform  10  and/or keyboard tray  70 A. According to the embodiment shown, the support members  106 ,  108  can have cutouts, e.g., forming an X-shape, in order to decrease weight and material, however, other configurations are possible. 
     Referring to  FIGS. 22-24 , another embodiment of the adjustable desk platform is shown. The embodiment of  FIGS. 22-24  is substantially the same as shown and described in connection with  FIGS. 18-21 . For example, the adjustable desk platform of  FIGS. 22-24  can include the same or similar pivot arm sets  30 , locking set(s)  40 , biasing mechanism(s)  50 , reinforcement member(s)  60 , counterweight, legs, and/or other features of previously-described embodiments. Accordingly, only additions or differences from previous embodiments are described below. 
     According to an aspect of the embodiment of  FIGS. 22-24 , the adjustable desk platform can include a plate  110  that serves as a common mounting point for various components, such as the upper platform  10 , the pivot arm sets  30 , the locking sets  40 , the keyboard tray  70 A, etc., and related components. Accordingly, instead of mounting these parts to the upper platform  10  itself, they can mount to the plate  110 , to which the upper platform  10  can also be mounted. This configuration can facilitate easier assembly and/or transportation of the adjustable desk platform, as the upper platform  10  may no longer need to provide mounting support for the various components. Additionally or alternatively, the plate  110  can facilitate replacement of the upper platform  10  in the event the upper platform  10  becomes damaged. According to embodiments, the plate  110  can be formed from metal, such as steel, however, other materials including wood, plastics, and composites are also possible. 
     Referring to  FIG. 22 , according to embodiments, the support members  106 ,  108  for the keyboard tray  70 A can be secured to the plate  110 , for example to the underside thereof, by rivets, screws, welding, bonding, or other fastening techniques known in the art. Referring to  FIG. 23 , the pivot arm sets  30  can additionally or alternatively be secured to the plate  110  (e.g., by the respective mounting brackets located on the underside of the plate  110 ), for example, by rivets, screws, welding, bonding, or other fastening techniques known in the art. As best shown in  FIG. 24 , the locking sets  40  and/or related components (e.g., handles  42 ) can additionally or alternatively be secured to the plate  110  using similar fastening techniques. The upper platform  10  can in turn attach to the plate  110 , for example, using screws extending through the plate and into the upper platform  10  from below. Alternatively, bonding, staples, or other fastening techniques known in the art can be used to attach the upper platform  10  to the plate  110 . 
     In the embodiment of  FIGS. 22-24 , as well as prior embodiments, the upper platform  10  and/or keyboard tray  70 A can be formed of a substrate such as wood (e.g., particle board), plastic, composite, or other material. A decorative layer can be applied over the substrate, for example, such as by painting, powder coating, or wrapping in a film such as a nylon film. One of ordinary skill in the art will appreciate based on this disclosure, however, that other techniques can be employed to provide a decorative and/or protective finish to the upper platform  10  and/or keyboard tray  70 A. 
     Although the keyboard tray  70 A is shown substantially fixed in position in  FIGS. 22-24  (and proceeding embodiments), alternative embodiments can include a keyboard tray  70 A that is adjustable in position. For example, according to embodiments, the keyboard tray  70 A can adjust up/down, left/right, forward/rearward, and/or can pivot about various axes with respect to the upper platform  10 . One of ordinary skill in the art will appreciate based on this disclosure that various adjustment and/or pivoting structures can be utilized to provide the aforementioned movements to the keyboard tray  70 A. 
     Referring to  FIGS. 22 and 23 , an elastic member  120  such as a spring, can be secured between the arms of each pivot arm set  30 . For example, the elastic member  120  can be secured at each end to one of the arms using known fastening techniques, such as screws, bolts, rivets, bonding, welding, etc. The elastic members  120  and/or pivot arm sets  30  can be configured for the elastic members  120  to relax as the upper platform  10  is moved upward toward the fully raised position, thus offsetting some of the force required for a user to raise the upper platform  10 . According to other embodiments, the elastic member  120  can comprise multiple springs or other elastic devices. 
       FIGS. 24 and 25  depict another embodiment of the adjustable desk platform that includes hand apertures  130  extending through the upper platform  10  in the vicinity of the handles  42  of the locking mechanisms  40 . Each of the apertures  130  can be shaped and configured to permit passage of all or a portion of the user&#39;s hand H therethrough. For example, each aperture  130  can be shaped and configured for passage of at least the four fingers of the user&#39;s hand H, as shown. According to embodiments, the apertures  130  can be substantially oval-shaped or can have the shape of an elongated slot, however, other embodiments are possible. Each aperture  130  can be located next to, or substantially next to, the respective handle  42 , such that when a user extends his fingers into the aperture  130  from above, his or her fingertips can touch and manipulate the handle  42 . According to embodiments, the lateral centerpoint of each aperture  130  can be offset from the lateral center of the respective handle  42  (e.g., the central pivot point in the embodiment shown) by a lateral distance W 3  of between about 2 and about 4 inches, however, other embodiments are possible.  FIG. 25  depicts the handles  42  after the user as moved them from the locked position toward the unlocked position. 
     The arrangement of the apertures and handle  42  can be used on any of the embodiments of adjustable desk platforms described herein. The arrangement of apertures  130  and handles  42  can be useful in embodiments having a wide upper platform  10 , for example and without limitation, those with a width W 1  of about 48 inches or greater. For example, with embodiments having an upper platform  10  of this size, it may be difficult or uncomfortable for the user to reach around the lateral ends of the platform to reach the handles  42  (e.g., due to limited wingspan). Accordingly, the apertures  130  can allow the handles  42  to be separated by a comfortable width W 2  of between about 18 and about 36 inches, for example, between about 28 and 32 inches, while the upper platform  10  has a larger overall width W 1 . 
     The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. For example, the arrangement of features with respect to the upper platform and the lower platform, such as, e.g., the locking mechanism, can be reversed. All examples presented are representative and non-limiting. The above-described embodiments of the invention may be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.