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The object of lap position is to hold the locomotive braking conditions as they are after making a graduated independent application, and should be used at no other time than after graduating on, or graduating off,
Fig. 38.—S-6 Independent Brake-Valve. Top view of transparent
rotary valve, and plan view of rotary-valve seat. Slow-application position.
the locomotive brake when the automatic brake-valve is in running position.
Slow Application, the fourth position, is represented in Fig. 38. Port e through the rotary valve is still per
BRAK Rotary Valve. Application Positions mitting reducing-valve pressure to flow to the top of the valve. The small port, m, in the face of the rotary valve is now in register with the port in the seat “to application cylinder”; through an interior cavity in RELEASE
Copyright, 1909, by The Norman W. Henley Publishing Co.
Fig. 39.—S-6 Independent Brake-Valve. Top view of transparent
rotary valve, and plan view of rotary-valve seat. Quick-application position.
the rotary valve port m is connected with the groove of port e, permitting reducing-valve pressure to flow to the application cylinder of the distributing valve, in which it acts as previously described to apply the locomotive
brake. The slowness of an independent application in this position is due to the very small size of port m through which the application-cylinder pressure is fed. All other ports in the rotary valve and seat remain as in the lap position.
The fifth and final position of the S-6 INDEPENDENT BRAKE-VALVE, as shown in Fig. 39, is that of Quick Application. The conditions are exactly the same as in the previous position, except that the rotary valve has turned far enough to bring the large groove of port e in its face into connection with the "application-cylinder ” port in the seat, providing an enlarged passage for the flow of reducing-valve pressure to the application cylinder of the distributing valve, and effecting a quick application of the locomotive brake.
The B-6 Feed Valve
THE B-6 FEED VALVE.
The B-6 FEED VALVE furnished with the No. 6 EQUIPMENT, photographic views of which are shown in Figs. 40 and 41, is the common slide-valve feed valve, the duty of which is to regulate pressure supply to the brake pipe, but improved by the hand-wheel regulating device and an enlarged regulating valve. In the ordinary automatic 'equipment, the feed valve was attached directly to, and was considered a part of, the automatic brake-valve; in all E-T equipment, it is located in the line of one of the two pipes that supply main-reservoir air to the brake-valve. The pipe that is directly supplied by the feed valve leads to the automatic brakevalve, and is called the feed-valve pipe, and in Running and Holding positions of the brake-valve it is in open port connection with the brake pipe.
All forms of FEED VALVE are interchangeable. As originally designed for attachment to the G-6 automatic brake-valve, the feed valve hangs downward in its proper position; in its application to the previous styles of the E-T brake it was turned upside-down-sticking upward; while in the No. 6 equipment we find it again turned down in its rightful position; and the reasons follow.
There are two air ports side by side in the connecting face of the feed valve, and as we stand in front of the
G-6 brake valve the left one is the entering port for main-reservoir pressure, and the right one is the port of exit, or brake-pipe connection. As used in the E-T equipment, the feed valve is attached directly to a "pipe bracket” (note appearance in Figs. 40 and 41), and as
Fig. 40.—The B-6 Feed Valve. Valve and pipe bracket complete.
usually placed, the main-reservoir air enters the pipe bracket from the right. The pipe brackets of the No. 5 equipment were simply made-right-hand pipe connection leading to right-hand face port, and left-hand pipe connection to left-hand face port; this would have