Adjustable desk frame

A frame to support a work surface so that the work surface is adjustable height, said frame comprising:

• a base to rest upon a floor and including a pair of vertical members in which are transversely spaced, generally parallel and co-extensive;
• a sub-frame supported on the base for adjustable vertical movement relative thereto and to support the work surface, said sub-frame including a pair of vertical members guidably supported by the base vertical members, the sub-frame vertical members being transversely spaced, generally parallel and co-extensive and arranged with respect to the vertical members of the base so that each vertical member of the base is engaged with a respective one of the vertical members of the sub-frame to form a respective pair of vertical members;
• and
• drive means operable by a user to move the vertical members of the sub-frame thereby to adjust the height of the work surface while maintaining said work surface in a desired orientation, said drive means including a vertical first shaft extending between the base and sub-frame in proximity to an associated pair of vertical members for rotation about a longitudinal axis of said first shaft, thrust means supporting said shaft on said sub-frame, a nut mounted on said base so as to be fixed thereto and threadably engaged by said shaft, whereby rotation of said shaft causes longitudinal movement of said shaft and movement between the vertical members of said associated pair of vertical members, a rack gear mounted on each of the vertical members of said sub-frame, a horizontal second shaft extending between the vertical members of said base and rotatably mounted therein, and a pair of gears fixed to said second shaft, each gear being engaged with an associated one of said rack gears so that the vertical members of said sub-frame move in unison.