Automatic last line monitor for typewriter - has roller sensor with optical or acoustic indicator switch

摘要

An automatic last line indicator for typewriters and similar machines provides a visual and/or acoustic signal to the machine operator to enable the operator to ensure that the last line is neither too low or too high on the sheet. A monitor sensor actuator (1) is mounted on bushes (6) on the left or right of the front of the typewriter carriage and near or between already existing parts. A small hollow chamber (2) in the bottom of the actuator (1) contains a control element in a spring (7) with a sensor (5) and a bell stop (8). The sensor (5) engages an annular slot (11) about 1 mm wide and 3 to 5 mm deep on the typewriter roller (9) about 10 to 20 mm from its end. An electrical switch contact (10) in the spring chamber (2) activates the optical or acoustic indicator.