GB1313561A - Typewriters - Google Patents

Abstract

1313561 Typewriters BROTHER KOGYO KK 28 July 1970 [4 Aug 1969] 36468/70 Heading B6F Letter spacing escapement mechanism in a typewriter includes a repeat-spacing key 55 whereby the platen carriage is repeatedly stepped while the key is depressed. The key 55 is linked to a bell-crank lever 46 and when depressed pivots the lever 46 clockwise to urge a nose 18c of a feed pawl 18 into engagement with an escapement wheel 16 through a spring 48 acting against a spring 21. The pivotal movement of the pawl 18 disengages a keep pawl 19 from the wheel 16 by engagement of a stop 18f on the pawl 18 with an arm 19c of the pawl 19. The escapement wheel 16 is thus permitted to rotate half a tooth increment under urging by a spring drum 33 until a successive tooth of the wheel 16 strikes the nose 18c. The impact urges the nose 18c out of engagement with the tooth, the pawl 19 being brought back into engagement by a connecting spring 23. The spring 48 then urges the pawl 18 back into engagement with the wheel 16 for a repeat spacing cycle. In normal operation, a space bar 45 or character key (not shown) acts through a lever 38 or 37 respectively to rock an actuator 24 having a roller 26 engaging an arm 18d of the pawl 18 to urge the pawl nose 18c into engagement with the wheel 16, impact disengagement of the nose 18c being prevented by the actuator 24 resisting clockwise pivotal movement of the pawl 18. The tension of the spring 48 may be adjustable.