GB1242782A - Improvement in type bar actuating mechanisms for typewriters - Google Patents

Abstract

1,242,782. Typewriters. LITTON BUSINESS SYSTEMS Inc. 22 May, 1969 [8 Oct., 1968], No. 26249/69. Heading B6F. A type lever actuating mechanism comprises a continuously driven toothed snatch roll 28, a sub-lever 23 pivoted at 26 and connected to a type lever 35, a pawl 18 adapted upon depression of a corresponding key lever 10 to be rocked into engagement with a tooth of the snatch roll 28, a spring 20 biasing the pawl 18 out of engagement with the teeth of the snatch roll 28, and a lost motion connection between the pawl 18 and the sub-lever 23. The mechanism prevents repeat action of the type lever 35 if the key lever 10 remains depressed too long by engagement of an ear 16 with an end surface 15b of a hook 15 on the key lever 10. The hook 15 is normally positioned above the ear 16 to rock the pawl into snatch roll engagement upon depression of the key lever. Impact adjustment.-The extent of the rocking movement of the pawl is limited by a finger 34 which is settable by bending and which controls the time of engagement between the pawl and the tooth of the match roll. Machine drives.-The snatch roll is driven by an electric motor (44, Fig. 2) through a belt drive and a flywheel 41 which is connected to a shaft 42 of the snatch roll through a resilient coupling comprising a pin 48 on the flywheel located in a slot 51 in a lever 45 fixed to the shaft 42, the lever 45 and pin 48 being coupled by a spring 52. On engagement between the snatch roll 28 and the pawl 18, the spring 52 is extended and the snatch roll slowed down, but, during the stroke of the type lever 35, the spring contracts, to accelerate the snatch roll and hence the type lever 35.