GB1049820A - Improvements in or relating to printing mechanisms - Google Patents

Abstract

1,049,820. Selective printing. INTERNATIONAL BUSINESS MACHINES CORPORATION. Dec. 7, 1964 [Dec. 17, 1963], No. 49618/64. Heading B6F. [Also in Division G4] In a high-speed printer operating from the output of a computer, a continuously driven type wheel 27 is mounted on a hanger 30 which is rocked by a cam 32 drivingly clutched for a single revolution at any selected one of a plurality of times within a type-wheel cycle so that a selected character on the type wheel is forced against a paper 25 on platen 22. Although a single print wheel may be employed for printing on a tape, as described, the printer comprises 120 type wheels so that a line of characters may be printed at a time. Each of the type-wheels 27 is continuously rotated by a cylindrical gear 28 and each individually mounted on a hanger 30. The selected characters (see Division G4) causes the operation of an energizing signal to be applied to a print magnet 36 one of which is provided in each column position. A slide 92 is moved which pivots a knock-off lever 86 clockwise: this allows a print clutch latch 80 to pivot counter-clockwise so that a print clutch dog 72 is pulled by a spring 74 about a pivot 73 whereby the hanger engaging cam 32 is clutched to a continuously rotating twelve-tooth reamer 70. The reamer 70 has teeth disposed on spirals having an angle of 7 degrees relative to the axis. The reamer rotates at 400 r.p.m., cam 32 engages a follower 66 on the type-wheel hanger 30 and thus swings the type-wheel to effect printing. Since the reamer 70 makes four revolutions to one revolution of the typewheel the electrical control determines in which “-revolution the swinging of the hanger 30 occurs. After printing the L.H. end of the dog 72 is arrested by the now released latch 80 and the print cam 32 is held stationary between a print cam detent 76 and the print latch 80. Electrical control.-Signals to determine the position of the type-wheels which are fed to a comparitor (see Division G4), are generated by a code wheel (42, Fig. 2, not shown) containing forty-eight radially symmetrical binary patterns (43) and an outer radius clock track (45). The code wheel (42) is a solid disc with perforations corresponding to the binary code and a single light coacts with a number of sensors (48) to provide the comparitor (40) with signals. Type-wheel construction.-The type-wheels 27 are formed so that the sides of type-faces 60 are cut as gear-teeth. Cleaning type-wheel.-A brush 61 engages the type-wheels to clean them during rotation.