Adjustable leg for supporting a table

Claim 1

A leg for supporting a table top the height of which can be varied comprising a support tube means for mounting substantially vertically, an externally screw threaded rod mounted within the support tube means axially thereof for supporting on an upper end thereof the table top and arranged so as to be axially movable from a retracted position at least partially within the tube means to an extended position to raise said table top, an opening in said tube at a position intermediate the length thereof and extending over a part only of the length thereof, a toothed gear member having peripherally mounted axially extending teeth and mounted within said tube means so as to surround said rod such that the teeth thereof over a part of a peripheral surface thereof are exposed at said opening, said gear member including an internal screw thread for cooperating with said externally screw threaded rod, a first and a second collar means each fixedly mounted within the tube means surrounding the rod and having an external surface in contact with an internal surface of said tube means, said rod having a longitudinal slot for engaging a projection of each of said collar means for preventing rotational movement of said rod relative to said collar means while allowing said axial movement, one of said collar means being mounted above said gear member and the other below said gear member to retain said gear member against axial movement whereby a rotation thereof acts to move said rod axially to said retracted and extended positions, a housing formed in two portions separated longitudinally of the tube means and arranged to clamp around the tube means at said opening, a manually operable lever mounted on said housing and arranged for reciprocation with said housing around an arc in a radial plane of the tube means, means limiting the angular extent of the arc, and a pawl mounted in said housing for reciprocation therewith for engaging said gear member and arranged to drive said gear member in one direction of reciprocation of said housing and to slip relative thereto in an opposed direction of the reciprocation of the housing, said pawl being rotatable about an axis at right angles to the leg through 180° so as to reverse the direction of drive and the direction of slip.