GB457170A - Improvements in telegraph, signalling, and like selective systems and apparatus - Google Patents

Abstract

457,170. Type-printing telegraphy. SIMS, V., 143, Park Road, Hendon, London. May 16, 1935, No. 13801/36. Divided out of 454,553. [Class 40 (iii)] The member whereby the transmitting contact is controlled in a key board or tape transmitter, particularly one of the kind described in Specification 454,553, is actuated by mechanism in which a single cam projection for each signal element acts in conjunction with a corresponding pair of abutments. In a keyboard transmitter the depression of each keybar 2, Fig. 2, shifts selected permutation bars 1 so as to bring one or other of two abutments 3 under the corresponding arm of a three-armed lever 6. The series of threearmed levers are lowered in turn during the transmission of an impulse-combination by cam projections 9, one for each impulse, acting upon arms 4 which carry the threearmed levers. Each of the latter, on being turned by an abutment 3, acts upon one or other of a pair of transverse bars 11, 12 ; these are common to all the levers and are mounted upon end plates 13 to which the motion is communicated so that a member 18, common to all the signal elements, sets a movable contact 19. For the start and stop impulses the end plates are rocked by the direct action of cams 9 on arms 21, 22. In a modification, Fig. 3, instead of a single lever 4 for each signal element, two levers 29 bearing abutments 28 are raised so as to engage one or other corresponding abutments on a contactsetting lever 25, according to the position of the latter as determined by the permutation bar 1. The lever 25 is thus rocked about its pivot 26 so as to set a contact 19. The Specification describes five further mechanisms, Figs. 4 to 8 (not shown), whereby the contact 19 is actuated jointly by the cams 9 and permutation bars 1. Instead of the contact 19, a contact spring 65, Fig. 9, may be clamped between two stiff flat springs 62 whose distance apart is adjusted by means of a set screw 63 so that the contact spring 65 is slightly buckled and remains in the position to which it has been set by studs 70 on a contact-actuating member 60. The spring makes contact with one or other of two resilient contacts 66, 67.