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The Blow-Down Timing Port

-it serves at emergency applications of the HighSpeed brake to so restrict the blow-down of application-cylinder pressure as to give approximately the same time between the maximum and minimum that is obtained in the use of the high-speed reducing valve.


Fig. 31 is a top view of the S-6 INDEPENDENT BRAKE VALVE used in the No. 6 E-T LOCOMOTIVE-BRAKE EQUIPMENT, with a diagram of the five operating positions of the rotary-valve handle; Fig. 32 is a photographic view of the brake-valve complete; in Fig. 33 the valve is shown removed from its pipe bracket; and Fig. 34 represents a sectional view of the complete brake-valve, with another view from the top as a plan of the rotary-valve seat, and a transparent plan view of the rotary valve.

Like the automatic brake-valve, the two body sections of the independent brake-valve are held together by cap screws, independent of the longer bolts that bind the brake-valve proper to the pipe-bracket section; and in general construction the two brake-valves are quite similar, including the handles, facilities for oiling, etc.

Referring to Fig. 31, the farthest position of the handle to the left is Release, and it is only necessary to use this position when the automatic brake-valve is in some other than running position, and it is desired to release the locomotive brake; the release position should be used, however, whenever the locomotive brake remains applied undesirably and the automatic brake-valve is in running position, as may happen on the second engine

S-6 Independent Brake-Valve

in double-heading. Release position discharges the application-cylinder pressure directly to the atmosphere through the exhaust port in the center of the bottom of the independent brake-valve; the handle will not remain in release position unless held there, a coil spring within the housing of the valve body

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Copyright, 1909, by The Norman W. Henley Publishing Co. Fig. 31.-S-6 Independent Brake-Valve. Positions of rotary-valve


turning the rotary valve to running position when the hand is removed from the handle.

Running Position is second, and the position in which the handle is standing as shown in the cut; it should always be left in this position, except when the

independent brake is applied, as a port in its rotary valve connects the distributing-valve release pipe through to the automatic brake-valve, thus admitting of the release of the locomotive brake in running position, if the automatic brake-valve is also in running position. Ordinarily, therefore in operating the independent locomotive brake its release is secured simply by replacing the independent brake-valve in running position.

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Fig, 32—S-6 Independent Brake-Valve, Complete,

In the third, or Lap, Position, the distributing-valve release pipe routing is discontinued beyond the rotary of the independent brake-valve, all the ports of which are blanked except the receiving port for reducing-valve pressure; in this condition, at an automatic application nothing unusual would be effected; but the locomotive brake could not be released by returning the automatic

Positions of Brake-Valve Handle

brake-valve handle to running position, until the independent brake-valve should be replaced in running position, also.

The fourth is Slow-Application Position; a very small port in the rotary valve permits reducing-valve pressure to flow quite gradually to the application cylinder of the distributing valve, permitting very fine graduating of the power applied to the locomotive brake.

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Copyright, 1909, by The Norman W. Henley Publishing Co. Fig. 33.—S-6 Independent Brake-Valve. Removed from pipe bracket

In the fifth, or Quick-Application Position, the supply of reducing-valve pressure to the distributing valve is given quickly, through a larger port in the rotary valve, and as it results in a sudden and heavy application of the locomotive brake this position should be used with judgment; there is but little danger of the rotary valve being moved to this position when the slow-application position is intended, as, when the handle passes

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