Backlash free drive for printing tabulator - has spring loaded toothed nuts integral with drive dogs

摘要

A backlash free drive for a printing tabulator is tension adjusted without dismantling. An axial spring forced between two nuts on a screwed spindle has its force transmitted through notched setting rings. The nuts (7) with integral flanges (1a, 1b) on the spindle (4) have straight dog (5, 6) coupled to rotate together with axial freedom. Each obliquely notched (8) nut meshes with a notched setting ring (2a, 2b), under spring (3) pressure outwards along the screw. Pressure varies with the angular setting. Oblique notch (8) and serrations (9) maintain the ring setting during driving.