| 摘要 |
1,248,683. Selective printing. ENGLISH NUMBERING MACHINES Ltd. 7 Jan., 1970 [31 Jan., 1969], No. 5307/69. Heading B6F. [Also in Division G4] In a line printer having a series of type wheels and a row of print hammers, a print hammer 103 is moved leftwards, in against a type wheel (not shown) by the operation of an electromagnet 113 which moves an arm 107 downwards into the path of one of the projections 130 on a continuously rotating drum 117. The electromagnet is de-energized before the hammer reaches the type wheel but momentum carries the hammer forward; a spring then returns the hammer to its home position. A single electromagnet may operate one, two or four print hammers, which are guided in their movement by rods 121, 123 and 124. The electromagnets are operated in sequence by timing pulses generated photoelectrically or inductively from the rotation of the drum 117. |
