GB423155A - Improvements in keyboard impulse transmitters for use in teleprinting systems - Google Patents

Abstract

423,155. Type - printing telegraphy. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin. July 6, 1934, No. 19935. Convention date, July 6, 1933. [Class 40 (iii)] In a keyboard transmitter in which contact members corresponding to the characters co-operate with a rotating contact cylinder, the operation of a contact member into engagement with the contact cylinder locks the contacts of all the other characters out of engagement with the cylinder until the transmission of the impulses of the character has been completed and the contact has been positively disengaged from the cylinder by a device which produces said disengagement independently of whether the corresponding key has been released or not. A key 3 can be depressed when a locking bar 16 common to all the keys and carried on a pivoted arm 5 moves to the right by the engagement of a roller 9 with a flat surface 11 of a constantly rotating cam. When a key is depressed a projection 18 on a pivoted member 17 individual to a key depresses a pivoted member 19 unlatching a spring biassed contact member 7 which is held from engagement with the contact cylinder by the bar 16 until the roller 9 engages the cylindrical portion 10 of the cam. The bar 16 on returning to the position shown allows the contact member 7 to engage contacts corresponding to the key depressed, locks the unoperated keys by entering the recesses 8 of the members 17 and by actuating to the left, the arm 17 of the depressed key releases the arm 19 from the projection 18. When the impulse combination has been transmitted the roller 9 again engages the flat surface 11 so that the locking bar 16 frees the keyboard and moves the lower end of the spring 7 to the right so that it is latched by a nose 20 on the member 19. No further impulses are transmitted until a key is depressed and this depression may be effected if the previous key has not returned to its inoperative position.