GB807311A - Improvements in or relating to word printing apparatus - Google Patents

Abstract

807,311. Typewriters &c. HANDLEY, J. Jan. 17, 1957 [Jan. 18, 1956], No. 1653/56. Class 100(4) A key-operated word printing typewriter which rapidly prints in succession the letters of the "word" or phrase selected has a rotating cam which completes electrical circuits to the required characters and a clutch for driving the cam from a continuously rotating shaft. Cam 28 on continuously rotating shaft 29 closes contacts 4. When a key is depressed, a circuit is completed through 2, 3, 4, 5, 30. Armature 31, moved by clutch magnet 5, releases pawl 33 which engages 37 so that cam 6 on shaft 35 rotates with wheel 37 which is itself driven from shaft 29 through 39, 40, 38. Armature 31 also closes contacts 9 to energize check magnet 8 which remains energised through holding contacts 27 as long as a key 1 is held depressed. Lock bar 10 is moved in behind bar 42 of armature 31 by 45 and armature 44 which moves up to magnet 8. By this time magnet 5 will be de-energized as contacts 4 will be open again. Cam 6 can thus make one revolution only however long a key is held depressed since 10 prevents 31 from releasing pawl 33. When key 1 is released armature 44 is spring- returned to rest. When a relay 3 operates, its eight contacts 11-18 all close. Contacts 11 are hold-contacts for relay 3 through contacts 19 which close when cam 6 revolves. Contacts 12-18 are connected to contacts 20-26 and through 7 to relays associated with the letters of the word to be printed. Contacts 20-26 are closed in succession as cam 6 rotates and corresponding letters are printed in the order required. Specifications 789,742, 791,432 [Group XL(a)] and 798,093 are referred to.