Patent GB-1220865-A (GB)
Title: Improvements relating to typewriters
IPC: B41J5/38
Filed: 1968-05-03
Abstract: 1,220,865. Typewriters. EPSCO Inc. (H. Funge). 3 May, 1968, No. 21076/68. Heading B6F. Mechanical combination selective devices; power operated machines.-In an electrical typewriter, depression of a character key (not shown) causes selected interposers 10 to move so as to disengage corresponding latches 12 from a bail 15 which is rotated downwardly about an axis 16 by a cam (35), Fig. 5 (not shown), acting on a roller 36 once for each impression, the latches 12 remaining in engagement with the bail governing movement of floating links 14 during rotation of the bail to position a corresponding character on a single element type head (not shown) in a printing position, switches 34 corresponding to the selected latches 12 being closed during the rotation of the bail to operate a tape punch mechanism (not shown) or a slave typewriter (not shown). The interposers may be moved by solenoids (44, Fig. 5) through cables 56 passing around pulleys 59 in response to signals from a punched tape reader (not shown) or a computer (not shown) or a master typewriter (not shown). An impression cycle may be initiated by a solenoid (75), Fig. 6, not shown, acting through linkages on a bail (68) which actuates a half-revolution clutch (not shown). Input arrangements other than keys; machines having dual functions.-Any character may be printed, or any typewriter function effected, by coded electrical impulses from an external source such as a punched-tape reader. The impulses from the reader energize corresponding solenoids for effecting the function, such as back spacing or letter spacing, or for selecting latches 12. The linkage operating each function also operates a corresponding switch for transmitting coded impulses to a secondary source such as a tape punch. The code employed (Fig. 2, not shown) comprises eight channels, channels 1-6 representing characters, channel 7 in combination with channels 1-6 representing functions, and channel 8 in combination with channels 1-7 being used to "delete" an incorrectpunching. Case shift mechanism; locking devices.-Depression of a key 103, Fig. 9, or energization of a solenoid 125 rotates the type head through 180 degrees to permit the printing of upper case characters. The keys 103 and solenoid 125 act through an arm 107 to release a ratchet 108 which undergoes a half revolution and thereby rotates a cam 109 through 180 degrees to effect the case shift. Release of a key 103 or energization of a solenoid 131 returns the type head to a lower case position. During rotation of the cam 109, a pawl 113 prevents initiation of a character impression cycle. Switches 114, 115 detect and transmit impulses corresponding to shift-down and shift-up operations respectively through engagement of contacts 117, 118 with a pin 116 on the ratchet 108. Tabulation mechanism.-The type head may be moved across the typing surface by a predetermined amount by depression of a key lever (82), Fig. 7, not shown, or by energization of a solenoid (89) acting through linkages to rotate a torque bar (85). A switch 86 detects a tabulation operation. During movement of the type head in a tabulation function, impulses from a tape recorder are suppressed by a capacitor circuit for a time corresponding to movement of the type head through fifty character spaces. Line spacing; carriage return.-A line space operation may be effected by depression of a key lever (196), Fig. 13, not shown, or by energization of a solenoid (204), both acting through linkages to pull downwardly a link (203) and cause an indexing pawl to rotate the printing platen one or more spaces. A switch (199) detects the operation. A line space operation is effected automatically with a carriage return operation, effected by depression of a key lever (170), Fig. 12, not shown, or by energization of a solenoid (185), acting to initiate operation of a clutch coupling a continously driven shaft (179) to a winding mechanism (not shown). A switch (182) detects the carriage return operation for transmission of a coded impulse, and a further switch (181) suppresses impulses from a tape reader while the carriage is in motion. Back spacing.-A back spacing operation may be effected by depression of a key lever (135), Fig. 10, not shown, or by energization of a solenoid (141), or by depression of an "erase" key (145) which back spaces the type head and the tape on a tape punch, and punches a hole in channel 8 of the tape in the back spaced position. A switch (140) detects the back space operation. Keys.-The tabulation key (Fig. 7) may be L-shaped, and the case shift keys, Fig. 9, may have a raised centre portion.