Mechanism for controlling the striking force and the non- striking in a typewriter

摘要

A mechanism for controlling the striking force and the non-striking in a typewriter comprises a driving shaft (4) provided with at least two cams (8, 9) corresponding to different striking forces, a sensor (13) for sensing the profile of these cams transmitting its motion to a printing head (1), displacement means (17, 18) for the sensor (13) and receiving means (20, 40, 41) for the control pulses. With a view to avoiding an important transfer of energy with the control pulses, the mechanism comprises a loaded spring (39) acting on the displacement means (17, 18) that causes them to cooperate with a stop device (34-38). This stop device (34- 38) is controlled in several positions by said receiving means (20, 40, 41). A return device (59, 61) driven by the driving shaft (4) brings back the displacement means (17, 18) in a so-called normal position after each complete rotation of this shaft (4). IMAGE