Abstract: An improved quiet impact printer mechanism for use with a typewriter or printer which includes a print hammer having a high effective mass at the print point for impacting a character pad against an ink ribbon, paper and a platen at a relatively low velocity. The pinter mechanism drive means includes a cam driven by a low torque reversible motor for moving a cam follower. The cam follower is coupled to the hammer by means of a pin and moves the hammer towards the platen. The cam may also cause movement of the hammer toward the platen under a predetermined series of controlled velocities.
Type:
Grant
Filed:
May 31, 1991
Date of Patent:
February 2, 1993
Assignee:
Smith Corona Corporation
Inventors:
Stephen M. Pawlak, Roger J. Rimbey, Mark D. Rodee
Abstract: A simplified type action for a typewriter comprising a type bar linkage having a toothed driving pawl pivotally mounted on an intermediate lever connected to a type bar through a link, and a key lever linkage including a key lever having a hooked lever pivotally mounted thereon and adapted to be engaged by a blade or tooth on a constantly rotating power or snatch roll to initiate a cycle of printing operation. The trigger lever is yieldably pivotable by the driving pawl upon its return stroke to assure the restoration of the type bar linkage to its normal position. Motion transmitting means best suited for such type action is also disclosed in which the power roll is composed of a center shaft and a toothed member rotatably mounted thereon, and an energy storing motion transmitting spring connects and is adapted to impart the motion of the former to the latter.