Patent GB-191319752-A (GB)
Title: Improvements in Electric Impulse Producing Mechanism.
IPC: H04M1/31
Filed: 1913-09-01
Granted: 1914-08-27
Abstract: 19,752. Western Electric Co., [Woodward, F. T., acting for Western Electric Co.]. Sept. 1. Impulse transmitters.-An impulse-transmitter is provided with a governor, which rotates with the part operating the contacts and is arranged wholly or partly above the plane of the finger-hold disk. The governor is enclosed between dished plates attached to the finger-hold disk. The numberplate rotates in both directions with the finger-hold disk. The governor is driven through a worm and worm-wheel by a pinion rolling round a spurwheel, which is prevented from moving in one direction by a pawl engaging a ratchet-wheel. The driving-spring is enclosed in a hollow spindle upon which the movable parts rotate. As shown in Fig. 2, the hollow spindle 18 contains a spring 40 wound upon a rod 37 connected to a plate 38. The spring 40 is also attached to the plate 38, which is prevented from rotating by its engagement with a recess in the spindle 18. The free extremity of the spring 40 is adapted to engage one of the grooves 55 on a lug 41 of the frame 26. The frame 26 is attached to a dished plate 21, which is rotatably mounted on the spindle 18. The wheel 22 is riveted to the plate 21, and may be provided with one long tooth 24 and a number of short teeth 23, which operate a contact 12 through a lever 14 controlled by a spring 15. A ratchet-wheel 33 screwed on the spindle 18 has a boss upon which a spur-wheel 34 is rotatably secured by a nut 35. A pawl 36, pivoted on the spur-wheel 34, co-operates with the ratchet-wheel 33. A spindle carrying a pinion 28 and wormwheel 30 is journaled in the plate 21 end frame 26. The pinion 28 gears with the spur-wheel 34, and the worm-wheel 30 gears with a worm on the shaft of the governor 27, which is journaled in the frame 26. An arc-shaped member 48 carrying the digits is fixed to the plate 21, and the finger-holds are formed in a member 31 of similar shape which is fixed to the frame 26. A dished plate 52, secured by screws to the frame 26, closes the apertures at the front of the transmitter, and a casing 10 is provided at the back. A stop 49 attached to the plate 11 extends in front of the finger-hold member 31. In operation, the subscriber rotates the finger-hold member 31 until his finger engages the stop 49. The frame 26, together with the parts journaled in it, the disk 21 and the spur-wheel 34, rotate with the member 31 and, at the same time, the spring 40 is wound up. The teeth 23, 24 on the wheel 22 oscillate the lever 14 without operating the contact 12. When the member 31 is released, the spring 40 drives the frame 26 and the parts carried by or secured to it in the opposite direction. The pawl 36 engages the ratchet-wheel 33 and locks the spur-wheel 34, so that the pinion 28 rolls round it and drives the governor 27 through the worm-wheel 30 and worm. The teeth 23, 24 then oscillate the lever 14 in such a manner that the contact 12 is operated to break intermittently the line circuit. In the modification described, the number of impulses transmitted is the complement of the digit selected, but by reversing the numbers on the member 48, the number of impulses may be made equal to the digit. A tooth producing a short impulse may be substituted for the tooth 24 producing a long impulse.