Adjustable support mechanism for a keyboard platform

Claim 1

An improved adjustable support mechanism for a keyboard platform assembly of the type including a platform supported by said support mechanism, said platform associated with a desk, said mechanism comprising in combination: a mounting plate for attachment to the underside of the desk surface member; a slide assembly cooperative with the mounting plate and slidable between an extended position and a retracted position; first bracket means projecting downwardly from the slide assembly, said first bracket means including an upper pivot and a lower pivot; a forward platform for support of a keyboard; second bracket means projecting downwardly from the forward platform, said bracket means including an upper pivot and a lower pivot; a first linkage arm between the upper pivots; a second linkage arm between the lower pivots whereby the arms and pivots provide a non-parallel unequal connecting linkages between the pivots, said arms defining means for tilting the platform from a first horizontal orientation to a second, not horizontal position as the platform is moved by the pivoting of the arms; and spring means for biasing the linkage arms about the axes of pivots wherein the spring means comprises a compressible fluid cylinder connected between the pivots of the first and second bracket means.