GB660263A - Improvements in or relating to power mechanism for typewriters and like machines - Google Patents

Abstract

660,263. Typewriters &c. INTERNATIONAL BUSINESS MACHINES CORPORATION. May 6, 1948 [June 5, 1947], No. 12492/48. Class 100 (iv). A power type action for a typewriter comprises a rotatable power roller 30 which is engaged by a cam 28 to actuate an associated type-bar 16, the blow imparted thereby being adjusted by means effecting disengagement of the cam 28 from the roller 30 at adjustable and differing points in the rotation of the cam by the roller 30. A key 10a, mounted on a lever 10, and pivoting about a pin 11 has a depending lug 10b which upon operation of the key, engages a release member 31 pivotally attached by a pin-and-slot connection 31b to a sub-lever 19. Release member 31 coacts with an extension 28c of the cam 28 which is pivoted at 19b to sublever 19 and moves it into contact with the power roller 30 which therefore continues to rotate the cam 28. The edge 28b of the cam is eccentric with the cam point 19b which is thus moved in an arcuate path to move the sublever 19 clockwise about a fulcrum 26a to effect, via link 20, movement of the typebar 16. The force applied to each type-bar 16 is individually adjustable by varying the point at which the cams 28 become disengaged from the power roller 30. This is effected by the contact of the extension 28c of the cam with a finger 34b of a combstrip 34 which is raised or lowered on a framework 33 by a screw adjustment 35. The clearance between the cam 28 and the power roller 30 is adjustable by longitudinal movement of stops 26 in slots in the frame 33, the stops being frictionally clamped in position by a resilient stop 37, within a channel-shaped bar 36. A spring 29 connecting the parts 19, 28 and the resiliency of the usual rubber covering of power roller 30 assist to produce a snappy disengagement with little slippage when the cam is forced off the power roller.