ENGINEER'S BRAKE VALVES 133 



will register the brake-cylinder pressure of the application. 

 When the engine is standing at a coal chute, a water plug, 

 or on a turntable, or while work is being done on it, the 

 independent brake valve should be left in slow-application 

 position so as to keep the locomotive brakes applied. 



Quick-Application Position. The quick-application position 

 is used when it is desired to make a quick application of the 

 independent brake. In such cases, the handle of the independ- 

 ent brake valve should be moved to quick-application position 

 and held there until the locomotive brakes are fully applied. 

 If the handle is not held in quick-application position, the 

 return spring 6 will move it back to slow-application position. 

 When the handle is in quick-application position, the rotary 

 valve forms a direct connection between the reducing-valve 

 pipe and the application cylinder of the distributing valve. 



RETURN-SPRING ARRANGEMENT 



The return-spring arrangement of the S-6 independent brake 

 valve, shown in Fig. 2, is intended to make it impossible for 



FIG. 2 



the engineer to leave the brake-valve handle either in release 

 position or in quick-application position. It consists of a 

 return-spring casing 5, a return spring 6, an upper clutch 13, 

 and a lower clutch 26, all of which when assembled fit in the 

 return-spring chamber in the body of the brake valve, This 

 chamber is shown in Fig. 3, which is a sectional view of the 

 brake-valve body with the return-spring arrangement removed. 

 In this view is shown the return-spring casing screw 8 and the 

 return spring stop 27. 



Moving the valve handle from running position to release 

 position puts the return spring under tension, so that the 



