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 pressure chamber contained in a housing cover on the other side of the abutment connected by a passage to the brake pipe. The cover includes quick action control apparatus including a quick action poppet type valve operably connected to the abutment for actuation of the quick action valve by the abutment from a normally closed to an open position in response to the operation of the abutment in one direction to a service braking position. The quick action poppet type valve vents fluid from the brake pipe when it is opened.
Passenger rail vehicle brake control valve apparatus includes, a control valve device of the type limited to direct release of the brakes, having service, emergency, and continuous quick service portions secured to a pipe bracket, and a graduated release valve portion governed jointly by brake cylinder pressure, brake cylinder exhaust passage pressure from the control valve device, and brake pipe pressure to at times modify output of the control valve device to provide for graduated control of the passenger rail vehicle brakes.
A single sided control valve wherein the service portion is mounted to the front face of a pipe bracket adjacent to the right face and the emergency portion is mounted to the front face adjacent to the left face. The brake pipe, brake cylinder and at least one reservoir port are on the back face and the brake pipe port is adjacent to the left face behind the emergency portion. Mounting brackets each include a horizontal flange with apertures to receive the fasteners which mount the mounting brackets to the vehicle and the horizontal flange which extends from the pipe bracket substantially past the front face and the center of gravity of the control valve. A combined dirt collector and cut-off cock is connected to the brake pipe port adjacent to the left face of the pipe bracket and includes a handle to the left of the left face.
A graduated release device which includes a valve, for example a check valve, connecting a control valve port and a brake cylinder port which prevents flow from the brake cylinder port to the control valve port. A graduating section controls the valve to produce graduated release of the brake cylinder in response to pressure on the brake cylinder port, brake pipe port and graduating volume port. An automatic mode section controls the valve to produce direct release of the brake cylinder in response to less than a predetermined value of pressure on the supply line port. If it is a two pipe system which includes graduated release, an appropriate pressure will appear on the supply line port and therefore allow the valve to be controlled by the graduating section. If less than a predetermined pressure is on the supply line port indicating that it is a single pipe system, the mode selecting section maintains the valve open such that it operates as a direct release valve between the control valve port and the brake cylinder port.
