GB907349A - Improved magnetic printer - Google Patents

Abstract

907,349. Typewriters. INTERNATIONAL BUSINESS MACHINES CORPORATION. May 6, 1960 [May 28, 1959], No. 16152/60. Class 100 (4). A typewriter comprises forming the characters as a magnetic image in a tape 2, powdering ink on the tape as it moves from the magnetic writing position to a print position where a line of printing is transferred to a permanent record 9 by pressure of bars 15, 16. The characters are formed on the tape 2 by a magnetic device comprising two non-magnetic discs 35, 36, Fig. 3, into which magnetic type inserts 4 are arranged, the one in disc 36 being the mirror image in the insert immediately above, in disc 35. The tape 2 travels in an air-gap between the two discs and an image is formed when a core 40 is energized by the discharge of a condenser 91 upon the operation of the appropriate key 1. A compensatory magnetic insert 39 balances the flux passing through the type character. The condenser 91 is controlled by a thyratron 88, a relay R1 and a commutator arrangement 49-52 driven in synchronism with the magnetic type-wheel. The rotating arm 48 travels at twice the speed of the wheel 3 since lower-case characters occupy one half of the perimeter and capital letters the other. The thyratron is fired when the arm 48 reaches that contact 50 that is connected to a charged condenser 81 because the appropriate key has been depressed. Further rotating arms and contacts on the type wheel shaft 32, in conjunction with the operation of a space-shift key 77, determine in which revolution of the arm 48 printing is to occur and thus determines the case of the character printed. Letter-spacing.-The tape is letter-spaced by the operation of a pawl 100 by a magnet 101; this allows the tape to be fed by a shaft 97 connected through a friction clutch 96 to a drive 95 from a motor 24. Tabulating.-The tape with the characters printed thereon may be moved to a particular position with respect to the permanent record 9 by the operation of a tabulation key 12. This causes a condenser 135 to operate a relay R3 and pawl 100 is released due to operation of magnet 100 which is held through contacts 144. The relay is released in accordance with predetermined stops fitted in holes 140 in a disc 139. Inking and transferring from tape to permanent record.-The magnetic image on the tape 2 is inked in a device 6, Fig. 5, not shown, which blows a metered quantity of ink in the form of magnetic powder over the tape. A screen 8 reflects the line of printing so the operator may see it, but allows vision through it on to the record 9. The line of characters is transferred to the record by pressure bar 15 and heated pressure bar 16 which are pressed together by a mechanism operated from a cam 175 driven from a clutched drive 177-180 controlled by a print key 14. Paper guides.-At the same time as the pressure bars close, the tape 2 is tilted from a horizontal plane to a vertical one by guide mechanism 150, 151, 162 and cam 164. See Fig. 7 (not shown).