Improvements in or relating to impulse senders of the finger disc type

摘要

301,424. Telefonaktiebolaget L. M. Ericsson. Nov. 29, 1927, [Convention date]. Applied by speed responsive devices.-In impulse transmitters of the finger-hold type for telephone systems and in which the shaft of the speed-regulator is driven by worm gearing, the shaft is displaced axially during the setting of the dial so that the braking device of the regulator is inoperative. The dial and worm-wheel 6 are locked on a common shaft, and during the setting of the dial the worm-shaft 26 of the speed regulator moves downwardly in bearings 28, so that a brake at the upper end of the shaft 26 is put out of action. When the dial comes to rest at the set position, the shaft 26 over-runs the worm-wheel 6 and is thus raised to its normal position. The speed regulator comprises weights 33 pivoted to a collar 34 on the shaft and, during the return movement of the dial, the upper ends of the weights engage a concave braking surface 32 with substantially constant pressure. The frictional reaction varies with the speed of the shaft 26 as the weights 33 swing outwardly due to centrifugal action.