Patent GB-181711-A (GB)
Title: Printing telegraph receiver
IPC: H04L17/24
Filed: 1922-06-13
Abstract: 181,711. Morkrum Co., (Assignees of Krum, H. L.). June 13, 1921, [Convention date]. Electric type-wheel actions; case-shift mechanism.-Relates to printing telegraph receivers oi the kind responsive to combinations of impulse units (preferably five) of positive and negative or current and no current, and kept in phase with the received signals by start and stop mechanism. As described, the receiver is a type-wheel printer, the start-stop and selector mechanism being controlled by a single electromagnet responsive tc line currents. The receiver is driven from a power shaft through a friction device allowing it to start without shock when a clutch is engaged, and a friction device is used to arrest the moving parts when the clutch is disengaged. A typewheel 17 and toothed wheel 18 are mounted on a shaft 14, and are relatively adjustable to bring either of two sets of type on the wheel 17 into use. This adjustment to one of two positions is effected by line current by means of a device described below oscillating an arm 65. The arm is connected to wheel 17 and held by a pivoted catch 69 carried on wheel 18. Printing is effected on a paper tape by an oscillated printer arm 19 having a roller which presses the tape against wheel 17 when the selected type is at the printing position. A ratchet device 58 feeds the tape one step at each oscillation of arm 19. Arm 19 is given the printing movement by a spring 23, when a detent 25, normally holding the arm with spring 23 in tension, is released. This release is effected by the end 40 of a lever moved by a spring 42, but normally retained by the typeselecting arrangement. The selectors (five de. scribed) comprise members 29 mounted for pivotal and axial movement, co-operating with notched discs 30, 31. Normally, these members are positioned to the left, Fig. 4, but are selectively moved to the right by plungers 44, this movement being completed by a cam 51 carried on disc 30 and acting on the selected plungers. The plungers are returned by a cam 52, and the members 29 by cam 53. The selective movement of the plungers is initiated by levers 79, the lower end of each lever resting against a corresponding pin 78 slidably mounted, and extending into a corresponding depression in a cam ring 77. A sleeve 70 slidable upon, and rotating with, the shaft 14, has a roller (not shown) running over the cam ring 77 and pressed against it by a spring (not shown) so that the sleeve when free is reciprocated on the shaft. When a magnet 83 is de-energized, its armature 89 prevents movement of sleeve 70, but when energized by typeselecting current impulses the sleeve 70 is freed,. so that its roller selectively enters the depressions in the cam-ring and operates the corresponding pins 78. The discs 30, 31 are sonotched that selected members 29 release lever 28 when the required type letter is at the printing position. The printing arm 19 is also utilized to act on a pivoted member 68 and move arm 65 to give the type-wheel adjustment referred to above. The clutch device through which intermittent drive is effected comprises two members 100, 101. Member 100 is frictionally held between a fibre disc 105 and a spring washer 106, on a sleeve 97 driven from a motor through worm gear 95, 96. Member 101 is secured to a shaft 98 carrying a gear wheel 102 meshing with a gear wheel 74 on shaft 14. Shaft 98 is capable of limited longitudinal movement, being moved to the left to engage the clutch members, by a spring 109, and returned to disengage the clutch by a roller acting on a cam 115, and carried by a lever (not shown). This lever is held by a toggle-lever arrangement (not shown) engaged by a catch released by appropriate line current operating the armature 89. Part of the friction device for arresting the moving parts is shown at 133. Specification 187,563, [Class 40 (iii), Telegraphs, Electric], is referred to.