| 摘要 |
1,175,436. Selective printing machines. FRIDEN Inc. 10 Aug., 1967 [5 Dec., 1966], No. 36677/67. Heading B6F. Type wheels and type-wheel machines.-In a printing apparatus having a continuouslyrotating type-wheel 16 and a hammer 76 for selectively moving a character 68 on the wheel 16 towards a platen 22 for printing, the wheel is resiliently mounted so that it moves laterally in its plane when a character thereon is momentarily clamped by the hammer into printing engagement with a paper sheet on the platen; smearing of the impression is thus prevented. The resilient mounting may comprise a rubber member 60, Fig. 3, fixed between the hub of the wheel 16 and its driving shaft 64. Alternatively, a mounting block 53 for the shaft 64 may be made of elastically deformable rubber or the shaft 64 may be arranged to flex laterally. The type wheel 16 has radial spokes which are flexible in an axial direction and are relatively rigid in the tangential direction. The characters 58 on the spokes face towards the platen 22. A carriage 14 carries the wheel 16 and hammer 76 and is movable on bars 30, 32 lengthwise of the platen. Character selection; hammer impression.- On the shaft 64 of the type-wheel 16 is a decoding disc 66 forming part of a known magnetic or photo-electric system causing a signal to be applied to an electromagnet 78 to operate the spring-retracted hammer 76 when a selected type is at the printing position. Leter spacing and carriage return.-The carriage 14 is connected to the ends of a cable 44 trained around an idler pulley 46 and a driving capstan 48, the latter being connected to a source of mechanical power 50 which may be a known spring or electric motor-driven mechanism for letter-spacing the carriage and for returning the carriage. The lateral movement of the type-wheel 16 during printing as referred to above, tends to move the carriage 14 in letter spacing direction and thus aids the metal acceleration of the carriage during letter spacing.
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