A brake control device has a selective release accelerator which responds only to a normal release subsequent to an increase of brake line pressure initiated by the operator's brake valve. A first piston has one side subjected to air line pressure and the other side subjected to pressure in an auxiliary reservoir. The first piston controls an inlet valve to connect the emergency reservoir to the brake line. A second piston has one side subjected to brake line pressure and its other side to press...

Release valve apparatus capable of being actuated by the vacuum that can be created in a main air line (1) for indirect air brakes of rail vehicles, comprising a release valve (12) in a connection (pipes 8, 9) from the brake control valve (3) to the brake cylinder (10). The release valve (12) contains a piston controlled two-way valve (24, 27, 28), which unblocks the passage in the off position of the release valve (12). In the actuated position, on the other hand, it blocks passage and vents th...

A pilot mechanism for improving operation of various functions of the pneumatic brake of a train. The mechanism includes solenoid valves, controllable by either a radio/battery mode of operation or a train wire system mode of operation. The solenoid valves can be interposed in various passages in fluid communication with passages of a conventional ABD control valve, as modified to enable operation of the invention, to permit substantially immediate venting of air in those passages to atmosphere.

This invention relates to release/relief valves, trailer brake release valve, and apparatus for equalizing pressure and absorbing shock, as they pertain to pneumatic brake systems for buses, trucks, and trucks/semi-trailers, singular and in multiple combinations in automotive air brake installations; and more particularly to a differential pressure regulator quick release valve that employs a dilivery channel for directing and centralizing fluid pressure differentials to its base housing and the...

A quick release valve for releasing the locomotive automatic brake independently of the train brakes when an AB/D type freight brake control valve is used on the locomotive. A release valve normally establishes a fluid control passage between the control valve and a relay valve that controls the locomotive brake pressure. When a quick release is made, the release valve is actuated to interrupt this fluid control passage and exhaust the relay valve portion of the passage to release the brakes. At...

Brake control valve system for rail vehicle air brake, comprising an emergency brake piston (7) having a first piston chamber (9) loaded by the quick action chamber with a much greater volume than its second piston chamber (8) loaded by the brake line. The effective pressure surfaces of the service brake piston and emergency brake piston are substantially identical. The emergency brake piston controls a first quick action exhaust valve (15) for venting smaller amounts of quick action air per uni...

A fluid brake control system is provided including a brake control pipe and a control valve comprising a quick action chamber and an emergency slide valve operable from a normal to a service brake position in response to service reduction in brake pipe pressure, the emergency slide valve having a fluid pressure differential operated abutment disposed between a first pressure chamber within a housing on one side of the abutment subject to pressure of the quick action chamber, and a second pressur...

An upgraded railway freight car brake control valve device comprises a novel emergency valve portion that embodies therein a minimum number of simple and inexpensive poppet valves, one of which is a double seated valve, that replaces yet performs the same functions heretofore performed by more expensive slide type valves which slide valves, and the flat seats upon which they slide as they are shifted from one position to another, in their manufacture require a considerable amount of accurate mac...

An accelerated release valve is proposed for brake control valves, especially direct release triple valves, the accelerated release being triggered by rapid collapse or discharge of quick service volume pressure at commencement of a brake releasing mode.

A fluid operable brake control valve apparatus is provided which includes a brake cylinder valve for controlling the supply of fluid pressure into and out of a brake cylinder. The valve is operable by a main pressure responsive member moveable in response to changes in pressure when applied to a brake pipe. A quick service valve is operable in response to such a change tending to cause a brake application for connecting a quick service volume to the brake pipe to enhance the change at commenceme...