A pneumatic brake valve unit for a rail vehicle, includes: a main device (20) designed for selective control of a communication path between a brake pipe connector (18) and either an atmospheric exhaust line (19) or an auxiliary reservoir connector (16), such that the pressure at the brake pipe connector (18) is k times the difference between the pressure at a control reservoir connector (14) and the pressure at a main brake pipe connector (12), k being a proportionality factor; and a reset device (23) designed for selective control of a communication path between an air discharge member (54) and the control reservoir connector (14) between an open position when the pressure at the brake pipe connector (18) is atmospheric pressure and a closed position when the pressure at the brake pipe connector (18) is above atmospheric pressure.

A pneumatic brake valve unit for a rail vehicle, includes: a main device (20) designed for selective control of a communication path between a brake pipe connector (18) and either an atmospheric exhaust line (19) or an auxiliary reservoir connector (16), such that the pressure at the brake pipe connector (18) is k times the difference between the pressure at a control reservoir connector (14) and the pressure at a main brake pipe connector (12), k being a proportionality factor; and a reset device (23) designed for selective control of a communication path between an air discharge member (54) and the control reservoir connector (14) between an open position when the pressure at the brake pipe connector (18) is atmospheric pressure and a closed position when the pressure at the brake pipe connector (18) is above atmospheric pressure.

A trip cock valve for a brake system on a rail car includes a valve body that defines an inlet, a chamber downstream from the inlet, and an outlet downstream from the chamber. A piston is inside the chamber. A valve member operably connected to the piston has a first position that prevents fluid flow through the outlet and a second position that permits fluid flow through the outlet. A lever is operably engaged with the valve member to move the valve member from the first position to the second position. A valve position indicator downstream from the inlet is in fluid communication with the inlet when the valve member is in the second position.

A trip cock valve for a brake system on a rail car includes a valve body that defines an inlet, a chamber downstream from the inlet, and an outlet downstream from the chamber. A piston is inside the chamber. A valve member operably connected to the piston has a first position that prevents fluid flow through the outlet and a second position that permits fluid flow through the outlet. A lever is operably engaged with the valve member to move the valve member from the first position to the second position. A valve position indicator downstream from the inlet is in fluid communication with the inlet when the valve member is in the second position.

A work machine with a mechanical brake touch-up system includes a power source that provides power to a rotational element. The work machine includes a brake that is configured with a piston to selectively engage a frictional element rotationally coupled to the rotational element, a position sensor for generating a position signal of the piston, and a control valve configured to supply hydraulic pressure to the piston to selectively apply a retarding torque to the frictional element, a speed sensor for generating a rotational speed signal. The work machine includes a touch-up controller which is configured to detect a retarding condition of the work machine based on the speed signal, and, upon detection of a retarding condition, control the position of the piston to a touch-up position between an engaged and retracted position.

A brake distributor valve for a Russian railway vehicle includes a body defining a brake pipe passageway configured to be in fluid communication with a brake pipe, a reservoir passageway configured to be in fluid communication with a reservoir, and a reference pressure passageway configured to be in fluid communication with a reference pressure source. The brake distributor valve includes a service accelerated release valve having a valve member with a first position where the brake pipe passageway is isolated from the reservoir passageway and a second position where the brake pipe passageway is in fluid communication with the reservoir passageway. The valve member is configured to supply pressure from the reservoir passageway to the brake pipe passageway during a brake release event, where the valve member is actuated between the first and second positions based on a pressure within the reference pressure passageway.

A brake distributor valve for a Russian railway vehicle includes a body defining a brake pipe passageway configured to be in fluid communication with a brake pipe, a reservoir passageway configured to be in fluid communication with a reservoir, and a reference pressure passageway configured to be in fluid communication with a reference pressure source. The brake distributor valve includes a service accelerated release valve having a valve member with a first position where the brake pipe passageway is isolated from the reservoir passageway and a second position where the brake pipe passageway is in fluid communication with the reservoir passageway. The valve member is configured to supply pressure from the reservoir passageway to the brake pipe passageway during a brake release event, where the valve member is actuated between the first and second positions based on a pressure within the reference pressure passageway.

A quick service limiting valve includes a housing defining an interior chamber, a brake pipe passageway, and a brake cylinder passageway, a valve member received within the interior chamber of the housing, with the valve member including a body, a first seal, a second seal, and a valve spring. The body of the valve member defines a valve passageway, with the valve member having a first position where the valve passageway allows fluid communication between the brake pipe passageway and the brake cylinder passageway and a second position where the brake pipe passageway is isolated from the brake cylinder passageway. The valve further includes a follower assembly received within the interior chamber of the housing, with the follower assembly including a body, a first check valve, a second check valve, a diaphragm, and a follower spring.

A quick service limiting valve includes a housing defining an interior chamber, a brake pipe passageway, and a brake cylinder passageway, a valve member received within the interior chamber of the housing, with the valve member including a body, a first seal, a second seal, and a valve spring. The body of the valve member defines a valve passageway, with the valve member having a first position where the valve passageway allows fluid communication between the brake pipe passageway and the brake cylinder passageway and a second position where the brake pipe passageway is isolated from the brake cylinder passageway. The valve further includes a follower assembly received within the interior chamber of the housing, with the follower assembly including a body, a first check valve, a second check valve, a diaphragm, and a follower spring.

A trip cock valve for a brake system on a rail car includes a valve body that defines an inlet, a chamber downstream from the inlet, and an outlet downstream from the chamber. A piston is inside the chamber. A valve member operably connected to the piston has a first position that prevents fluid flow through the outlet and a second position that permits fluid flow through the outlet. A lever is operably engaged with the valve member to move the valve member from the first position to the second position. A valve position indicator downstream from the inlet is in fluid communication with the inlet when the valve member is in the second position.