GB700998A - Improvements in or relating to printing telegraphy - Google Patents

Abstract

700,998. Actuation of switches. TELETYPE CORPORATION. April 10, 1951 [May 10, 1950], No. 8284/51. Class 38(5) [Also in Groups XXIV and XL(b)] Sequence-switches and a switch for closing alarm contacts after a predetermined delay, for use in a telegraphic interconnection system (see Group XL(b) are actuated by ratchets controlled by constantly-rotating shafts. Sequence switches. Six sequence switches are operated from a common continuously-rotating shaft under control of individual magnets. Fig. 19 shows the mechanism for one such switch. A bail 641, common to all the switches, is oscillated between the full-line and dotted-line positions by an eccentric 636 on the shaft 609 and co-operates with two pawls 642, 643 connected together by springs 647, 648 and acting on a ratchet 644 carrying the contact-controlling cams 646. With the individual control-magnet 649 de-energized, pawl 642 is prevented by armature 651 from moving sufficiently to the right to drop on to the next tooth of ratchet 644 but, at each energization of the magnet, pawl 642 drops on movement of bail 641 to the right and advances the ratchet a halfstep on the next movement to the left, and pawl 643 is then effective to move the ratchet a second half-step when the bail moves again to the right. Delayed-alarm switch, Fig. 32. Magnet 633, when operated, withdraws a locking projection 826 from a lug 824 on a driving pawl 817 associated with a ratchet segment 821. Eccentric 816 on continuously-rotating shaft 609 reciprocates pawl 817 so that, after a predetermined time if magnet 848 has not operated, ratchet 821 operates lever 836 to close contacts 839 connected to an alarm 842. If magnet 848 operates within the predetermined time its armature withdraws the driving pawl 817 and holding pawl 832 releasing the ratchet segment.