| 摘要 |
<p>1498149 Selective printing INTERNATIONAL BUSINESS MACHINES CORP 28 Oct 1975 [23 Dec 1974] 44234/75 Heading B6F A print element 108 is rotated for character selection by the reciprocation of rack 114. The rack 114 has two sets of teeth 116, 118 which are selectively engagable with the pinion 112 depending on the case of character to be printed; the pinion following the completion of a printing cycle; i.e. selection and impression of a character, remains in contact with the rack engaged to effect the said cycle. As shown in Fig. 4 the rack is reciprocated by follower 128 fitting in groove 130 of cam 120, which is axially movable on shaft 168. Selection of the set of teeth 116, 118 to engage the pinion 112 is effected by the movement of an interposer 156 to transmit the motion of one of the cam followers 158, 162 to forks 140 which are able to slide the shaft 132. Movement of the interposer 156 is due to pneumatic actuator 170 or an opposing spring 154. In Fig. 1 one of the followers 40, 42 rocks shaft 32 to change the set of teeth 16, 18 engaging the pinion 12. The follower 40, 42 chosen depends on the selective energization of electromagnet 48. Changing the follower can only occur when the radially smaller part of disc 54 is aligned with lobe 56.</p> |
