Adjustable typewriter platform mechanism

A typewriter desk of the type having a desk top, a knee opening under a portion of said desk top, a typewriter platform recess in said desk top generally corresponding in location to said knee opening, a horizontally disposed typewriter platform being generally disposed in said knee opening, a plurality of jack-screws each being vertically disposed and rotatably mounted to said desk below said desk top and proximal to said typewriter platform recess for nontranslational rotation, and a mechanism for simultaneously rotating all of said jack-screws, the improvement which comprises:

• means for supportably attaching said typewriter platform to said jack-screws to receive lifting motion therefrom, to allow limited relative vertical motion between said typewriter platform and said jack-screws, and to permit limited relative horizontal movement between said typewriter platform and said jack-screws in two horizontal and orthogonally intersecting axes.

For use in an adjustable typewriter platform mechanism which includes a frame, a plurality of upright jack-screws rotably mounted on said frame, means for rotating said jack-screws in unison, elongated support-bars each operatively secured for vertical movement at the opposite ends thereof to two spaced jack-screws, said support-bars being channel shaped in cross-section, and a rigid typewriter-supporting platform secured to the support bars;

• the support-bars being secured to the jack-screws by means of mounting devices, each mounting device comprising a lift nut threaded onto a jack-screw and floatingly secured to an end of a support-bar whereby the support-bar may tilt by a predetermined amount without causing binding of the nut on the jack-screw, said lift nut being disposed between the flanges of the channel shaped support bar.