Patent GB-190800700-A (GB)
Title: Improvements in or relating to Electric Type-printing Telegraphic Apparatus.
Inventor: AGRELL GUSTAF AXEL MAURITZ
Filed: 1908-01-11
Granted: 1908-09-10
Abstract: 700. Agrell, G. A. M. Jan. 11. Telegraphs. - In a t y p e - printing telegraphic receiver, controlled by positive and negative strong and weak currentimpulses, the typewheel shaft is positioned by a laterally movable catch - mechanism co operating with two or more toothed disks, located side by side and capable of relative movement. The typewheel 7 is fixed to a sleeve 6 carrying at its other end a disk 3, against which toothed disks 1, 2 are pressed by a spring 10. The disks 1, 2, 3 are recessed to receive friction disks 11, 12, 13, which are driven by a constantly rotating shaft 4 but may slide laterally upon it. Pins 16, 17 project from the left side of the disks 1, 2 and co-operate with pins 18, 19 projecting from the right side of the disks 2, 3, in such a way that if the disk 1 is held in any position, the disk 2 can only be rotated until the pin 18 strikes the pin 16, and the disk 3 until the pin 19 strikes the pin 17. The toothed disks 1, 2 and the type-wheel 7 are shown in a developed state in Fig. 2. The disk 2 is provided with two rows of teeth, and each tooth corresponds to one letter of the type-wheel. If it is desired to select the letter X, the disk 1 is allowed to rotate one step to a tooth 26, and the catch-mechanism is then shifted to engage the right-hand teeth on the disk 2, which is then allowed to rotate two steps to a tooth 29, and finally, the catch-mechanism is again moved laterally so as to engage the next tooth on the left side of the disk 2. Thus, any letter can be selected by five or a less number of impulses including those for shifting the catchmechanism, which comprises two catches 31, 32 slidably mounted in a slide 33. When a magnet 68 is energized, the catch 31 is lowered, and the catch 32 is simultaneously raised by a lever 35. Lateral movement is given to the slide 33 by a pawl 43 aud magnet 40. When the catch-mechanism is moved to the left, the disk 1 is at once returned nearly to its starting point, until an arm 55 strikes a projection 54 on the slide 33. The line-currents pass through two relays 59, 60, which are so arranged that a weak positive current closes the circuit of the magnet 68 controlling the rotation of the toothed disks, a strong positive current completes the circuit of the magnet 40, and a strong negative current completes the circuit of the printing-magnet 47, which, besides actuating the printing-hammer 50, removes the detents 43, 52 from the slide 33 so that this slide is returned to its normal position by a spring (not shown). Weak negative impulses fill up the intervals between the other currents, and serve to return the polarized armature 61 to its normal position. The return of the slide 33 releases the disk 2, which then rotates until the pin 18 engages the pin 16. When the magnet 47 is de-energized, the type-wheel shaft is rotated until the pin 19 engages the pin 17. In place of the friction members 11, 12, 13, the disks 2, 3 may be connected by coiled springs directly to the continuously rotating shaft 4, which in this case is driven by a suitable motor through a friction clutch.