_'S 



S. BENT RUSSELL 



To show how different forms of coupling gangs may be em- 

 ployed, diagrams of two arrangements are shown in figures 

 5 and 6 and tables are used for others. In figure 5 the left hand 

 diagram FL known as a stream diagram shows diagrammati- 

 cally the form of the hypothetical channels that connect the 

 sensory terminals SO, SD and SL at the top of the diagram 

 with the motor terminals MO, MD and ML at the right of the 

 diagram. The broken lines show the direct channels that pre- 

 vail at first. The solid lines show the channels that are devel- 



SO SD SL 



IL 



IL 



IL 



ZL 



IL 



1 



IL 



=L — 0— ML 



IL 



IL 



IL 



IL 



■0-1 



a- 



O-0-, 



— -0 — MD 



-0- 1 



-EH 



Ll 



HZ- 1 



a— mo 



FL. 



FR. 



Figure 5. Coupling diagram and stream diagram for a 3-way diverging gang of 

 9 transmitters. 



oped by favorable experience. Figure 6 shows a similar stream 

 diagram referred to again later. 



In figure 5 the right hand diagram FR, known as a coupling 

 diagram, shows how the key and spur rods are arranged and 

 connected so as to work the transmitters. The key rods are 

 represented by vertical lines and the spur rods are shown by 

 horizontal lines. The bell crank connections to be used are 

 indicated. A single transmitter connected to one key rod cor- 

 responds to a direct channel. Two transmitters connected to 

 the same two key rods correspond to a diverging channel. Each 



