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The E-T Air-Brake Pocket-Book

as well as securing the full-on application of the rearward brakes before the slack could run in.

It has been found desirable in recent years to apply quick-action triple-valves to locomotive tenders, and this is particularly necessary when in case of doubleheading, the engineer of the leading locomotive operates the brakes, as, if both engines and tenders are equipped with plain triple valves it is quite commonly impossible for him to secure quick action of the train brakes, owing to the large volume of brake-pipe air to be reduced between his brake-valve and the quick-action triple on the first car, and the resistance to air flow due to the several short bends and possible elbows in the brake pipe of both locomotives. As the E-T locomotive brake depends upon the distributing valve for the regulation of brake-cylinder pressure, and the graduating portion of the ordinary distributing valve acts on the same principle as the plain triple-valve, it follows that it is just as necessary that the distributing valve should possess the same quick-action feature of brake-pipe air-vent at emergency applications; on the theory, however, that some railroads do not encourage the double-heading of trains, the Westinghouse Air Brake Company furnish the distributing valve of the latest improved E-T equipment, No. 6 type, without the quick-action device, unless such shall be specified when ordering.

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Fig. 18.—No. 6 Distributing Valve with Quick-Action Cylinder

Cap. Released and charging position.

Copyright, 1909, by The Norman W. Henley Publishing Co.

Displacing the plain cap, or head, of the lower portion of the distributing valve and substituting the “QUICK-ACTION CYLINDER CAP" is all that is necessary to change the No. 6 equipment to a quick-action locomotive brake, and Figs. 18 and 19 show the distributing valve with the improved attachment.

The E-T Air-Brake Pocket-Book




Fig. 18 represents the distributing valve with QUICKACTION CYLINDER CAP, with all operative parts in the released and charging position; the conditions that exist within the distributing valve are the same as were described in connection with Fig. 9 B, and are, presumably, well understood; the piping diagram of Fig. 9 A will also apply as an adjunct to this distributingvalve chart, and need not be reproduced.

Referring to the quick-action cylinder cap, the graduating spring, 46, and the graduating stem, 59, appear, as in the plain cylinder-cap, except that stem 59 is lengthened and made to engage the emergency slidevalve, 48, between its shoulders; with the graduating spring relaxed within its limit, as shown, the slide valve covers port j in the seat, and brake-pipe air entering at BP only fills the slide-valve chamber of the cylinder cap, flowing thence into chamber p of the distributing-valve proper, and, as usual, through feedgroove u to the pressure chamber.

The provision of passageway m that carries the brakecylinder air down to the lower part of the equalizing portion of the distributing valve is now seen to have

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