Adjustable desk platform

1. An adjustable desk platform comprising:

an upper platform defining a substantially planar work surface, and a lower surface opposite the work surface, wherein an edge of the upper platform defines a generally U-shaped recess having first and second lateral sides;

first and second lower mounting brackets extending below the upper platform, the first and second lower mounting brackets laterally spaced apart from one another;

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 upper mounting brackets extending upward from the base, the first and second upper mounting brackets laterally spaced apart from one another;

first and second sets of arms coupling the first and second lower mounting brackets to the first and second upper mounting brackets, respectively, wherein the first and second sets of arms are adapted to move the upper platform substantially in parallel with the base between a fully raised position and a fully lowered position;

a keyboard tray suspended below the upper platform, and adapted to support a keyboard, wherein the keyboard tray defines first and second lateral edges;

a first support bracket extending between the first lateral side of the generally U-shaped recess and the first lateral edge of the keyboard tray; and

a second support bracket extending between the second lateral side of the generally U-shaped recess and the second lateral edge of the keyboard tray;

wherein the surface area of the keyboard tray is less than one half of the surface area of the upper platform.

2. The adjustable desk platform of claim 1 , wherein the first and second support brackets comprise metal brackets.

3. The adjustable desk platform of claim 1 , wherein the keyboard tray is generally T-shaped.

4. The adjustable desk platform of claim 1 , wherein the substantially planar work surface is unobstructed.

5. The adjustable desk platform of claim 1 , wherein the upper platform moves rearward 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.

6. The adjustable desk platform of claim 1 , wherein the locking mechanism comprises:

a plurality of perforations located in the first or second set of arms;

a locking set fixed with respect to the upper platform or the base, the locking set including at least one anchor adapted to selectively engage at least one of the plurality of perforations, and

a handle connected to the anchor by a linkage, the handle adapted to selectively move the anchor into engagement with at least one of the plurality of perforations.

7. The adjustable desk platform of claim 6 , wherein the anchor is resiliently biased into engagement with at least one of the plurality of perforations.

8. The adjustable desk platform of claim 1 , further comprising:

a boss located on the first or second set of arms, the boss adapted to move through an arcuate path as the upper platform moves between the fully raised position and the fully lowered position; and

a first spring fixed in position with respect to the upper platform or the base, wherein movement of the upper platform toward the fully lowered position extends the first spring.

9. The adjustable desk platform of claim 8 , wherein the first spring is a compression spring.

10. The adjustable desk platform of claim 8 , further comprising a second spring fixed in position with respect to the upper platform or the base, wherein movement of the upper platform toward the fully lowered position causes the boss to bend the second spring.

11. The adjustable desk platform of claim 10 , wherein the second spring is a cantilever spring.

12. The adjustable desk platform of claim 10 , wherein:

the first spring extends between the boss and the upper mounting bracket or the lower mounting bracket; and

the second spring is secured to the upper mounting bracket or the lower mounting bracket.

13. The adjustable desk platform of claim 12 , further comprising a pivot point located adjacent to the second spring, wherein the boss is adapted to bend the second spring about the pivot point.

14. The adjustable desk platform of claim 1 , further comprising:

a first spring fixed in position with respect to the first lower mounting bracket, wherein movement of the upper platform toward the fully lowered position extends the first spring.

15. The adjustable desk platform of claim 1 , wherein the first and second lateral sides of the generally U-shaped recess are joined by a third side that is angled with respect to the first lateral side and the second lateral side.