An integrated gladhand and quick-release valve for tractor-trailer highway vehicles is mounted on the tractor, as opposed to the trailer, so the operator of a particular tractor will uniformly have quick-release capability for any trailer drawn by the truck. The integrated gladhand and quick-release valve provides an inlet port for fluid communication from the tractor brake system and an outlet port for fluid communication to the trailer brake system. The intermediate passageway that provides fluid communication between the inlet and outlet ports contains a valve element. The valve element may be apertured to allow limited, continuous fluid communication between the tractor and trailer brake lines. During the quick-release mode, the tractor side is substantially isolated and the trailer side is vented through an exhaust port. The present invention provides a uniform and safe braking system for tractor-trailer highway vehicles where the tractor operator does not own or maintain the trailers. The present invention provides an improved integrated gladhand and quick-release valve that reduces the response time of trailer brakes to application and release of the brake pedal and reduces hysteresis effects.

An improved railroad train braking system causes automatic braking of cars which have been isolated from the braking control of the engineer. A safety apparatus (18), having structure permitting discharge of pressurized air from the system at a predetermined rate, is coupled at the rearmost end of a train brake pipe (26). Pressurized air from the braking system of cars located rearwardly of a closed aircock is permitted to discharge from the system through the safety apparatus. Air distribution control valves (40) in the affected cars (14, 16) sense the reduction in pressure, and active the brakes (42).

A self-contained self-muffled pneumatic gun for dispensing one or two combinable flowable materials from a prefilled package or cartridge. The gun has a first hollow chamber for retaining the package in fixed relation, the package containing the materials to be dispensed and either having a dispensing valve thereon or not as known in the art. A second hollow chamber of the gun retains an axially-movable hollow tubular piston for pneumatically forcing discharge from the gun and through a metering, mixing and/or dispensing nozzle. The hollow piston has a quick-release valve mounted internally in its head portion for rapid release of pressurized gas internally of the gun body for its relatively quiet operation. Internal release of the gas pressure within the head portion serves to prevent noisy operation of the gun. The gun is capable of economical manufacture with the valve components being formed from essentially non-machined moldable components.

A pressure relief valve for a railway emergency brake system that is simple in construction, easy to manufacture and to assemble and that, in operation, is self-cleaning of brake pipe dirt and debris. The inventive valve comprises a valve body having a hollow space being divided by a diaphragm into a first and a second chamber. Chambers are coupled via an orifice in the diaphragm, coupling pressure from the first chamber to the second. The valve comprises a peg aligned with the orifice, penetrating and cleaning the latter when the diaphragm moves from a closed position into an open position.

A flow control device having a first port, a second port, a third port and the movable member. In a first mode, the movable member seals the second port while allowing fluid flow between the first and third ports, wherein the differential pressure between the first port and third port, during the first mode, is about zero. In the second mode, the movable member seals the first port while allowing fluid flow between the third port and second port, wherein the movable member is adapted to transition from the first mode to the second mode in response to a small change in differential pressure.