AN IMPROVED TELEPHONE SET 



259 



of contacts operated by a rubber stud on the main gear close and short t he 

 receiver whenever the fingerwheel is rotated from its normal stopped 

 position. When the dial returns to normal after ''rundown" these contacts 

 are opened. The cam is assembled on the pulsing shaft so that its major 

 axis is rotated in the rundown direction through the angle 6 as shown in 

 Fig. 13 in order to provide an adequate interval between the last closure 

 of the pulsing contacts and the opening of the receiver shorting contacts. 



DRIVE BAR- 



SPRING 



GOVERNOR 

 -- CASE 



Fig. 14 — Dial governor. 



During this time, pulsing transients decay sufficiently so that clicks are not 

 present when the receiver short is removed. 



In achieving the close control of the make-and-break time in the pulsing 

 mechanism, improved speed regulation of the dial plays a very important 

 part. This is accomplished by a new type of governor, Fig. 14, in which an 

 auxiliary bar has been added to drive the weights in the opposite direction 

 and at a higher speed than in previous governors. As a result the new gover- 

 nor maintains a more constant dial speed under conditions of varying co- 

 efficient of friction between the braking studs and the case and varying input 

 torque, as shown on Fig. 15. 



