GB768468A - Improvements in typewriters - Google Patents

Abstract

768,468. Typewriters. INTERNATIONAL BUSINESS MACHINES CORPORATION. Jan. 4, 1955 [Jan. 4, 1954], No. 191/55. Class 100(4) A typewriter has an arcuate group of pivoted type bars 10, a plurality of bars actuating links 20, each operatively interconnected with a type bar, one or more cam surfaces 35 carried on a drum 30 and continuously movable in a path adjacent one end of each link, and one or more actuators for selectively moving the links to bring their ends into the path of the cams which initiate. movement of the selected link and bar to force the bar into contact with the copy. In the construction shown in Figs. 1 and 4 the cams 35 are mounted on the inner surface of the rotating drum 30 and links 20 are normally held out of the path of the cams by engagement of a spring-pressed ball 58 with the pointed end of the link. When a key 40 is depressed it acts through pawl 48, ratchet 49, cable 45, and lever 51 to pull the end of the corresponding link 20 radially outwardly of the drum, and with the ball 58 then acting on the bevelled nose 59 of the link the latter is moved into the path of cam 35 to actuate the type bar 10 against springs 22, 29. The force of spring 29, and hence the strength of the impression on the platen is varied commonly by plate 27 and individually by nut 28. The parts are returned by springs 43, 22, 29. The links may be deflected and advanced by individual electromagnetic means, 'but in the construction shown in Figs. 6 and 7 links 20 are moved into the path of the cams by fingers 96 which normally register with the space between a pair of links, are deflected, to the right or to the left to register with the desired link by electromagnetic means, and advanced axially to move the links by further electromagnetic means. Each finger 96 passes through an aperture in one of a series of tabs 100 on four sector-shaped formes 102 or 104, rotated clockwise or anticlockwise about bars 106, by a common armature 116, according to which solenoid 108 is energized, so that the group of fingers connected with the sector register with one or other of the links associated with each 'finger. The armature 92 of each motive means 90 is connected to a group of four fingers 96, is advanced by energization of solenoid 89, and returned by spring 94, but the arrangement is such that although a group of fingers is deflected by the movement of one sector 102 or 104, and a group advanced by a means 90, only one finger is both deflected and advanced so that one type bar only is actuated. Individual or common switches to complete circuits for energizing solenoids 89, 108 may be closed by actuation of a type key. The invention may be applied to a card operated typewriter.