Railcar cushion unit

In a cushioning device for absorbing impact between railway cars having a fluid recovery reservoir, a cylinder containing a mixed gas and liquid, the cylinder having a cylinder wall and being located within the reservoir, a bulkhead at one end of the cylinder and a cylinder head at the other end of the cylinder having a hole therethrough, a piston located within the cylinder which moves from an extended position to a contracted position, the piston having a rod extending through the hole for cushioning the impact, coupling means on the rod and the bulkhead opposite the rod for connecting the cushioning device between two railway cars, and a plurality of egress ports located within a portion of the cylinder wall between the piston and the bulkhead when the piston is in the extended position, the egress ports being located at various distances from the bulkhead, the improvement comprising:

• plurality of spring-biased valves, each coupled within one of the egress ports, the valves being openable to allow fluid to flow only in one direction through said egress ports from the cylinder to the reservoir in response to a selected fluid pressure differential within the cylinder;
• and wherein each of the valves comprises:
• a body having a longitudinal axis which couples to the egress port;
• a valve piston slidingly mounted within the body and having an axial passage;
• a valve seat joined to the body, the valve seat being a frusto-conical recess;
• a frusto-conical shaped head joined to the valve piston which sealingly engages the valve seat for preventing fluid flow through the valve;
• a plurality of valve ports extending through the head and joining the axial passage, the valve ports allowing fluid to pass through the axial passage of the valve when the head is unseated from the valve seat;
• and
• resilient biasing means for urging the head of the valve piston into engagement with the valve seat.

A cushioning device for absorbing buff and draft movement between railway cars, comprising in combination:

• a fluid recovery reservoir;
• a cylinder containing a mixed gas and liquid fluid, the cylinder having a cylinder wall and being located within the reservoir;
• a bulkhead at one end of the cylinder and a cylinder head at the other end of the cylinder having a hole therethrough;
• a piston located within the cylinder which moves from an extended position to a contracted position, the piston having a rod extending through the hole for cushioning the impact;
• coupling means on the rod and the bulkhead opposite the rod for connecting the cushioning device between two railway cars;
• a plurality of egress ports located within a portion of the cylinder wall between the piston and the bulkhead when the piston is in the extended position, the egress ports being located at various distances from the bulkhead;
• a plurality of pressure relief valve means, each coupled to one of the egress ports for allowing fluid to flow only in one direction through said egress ports from the cylinder to the reservoir in response to a selected fluid pressure differential between the cylinder and the reservoir due to buff and draft movement;
• a restoration port located in the cylinder wall adjacent to the cylinder head for allowing flow of the fluid to the reservoir as gas pressure in the cylinder moves the piston toward the cylinder head when free of buff and draft movement;
• and
• a restoration valve coupled to the restoration port for preventing flow through the restoration port if draft movement occurs of a magnitude above a selected level during restoration, causing fluid to flow through any of the pressure relief valves located between the piston and the cylinder head.

A cushioning device for absorbing impact between railway cars, comprising in combination:

• a fluid recovery reservoir;
• a cylinder containing a mixed gas and liquid, the cylinder having a cylinder wall and being located within the reservoir;
• a bulkhead at one end of the cylinder and a cylinder head at the other end of the cylinder having a hole therethrough;
• a piston located within the cylinder which moves from an extended position to a contracted position, the piston having a rod extending through the hole for cushioning the impact;
• coupling means on the rod and the bulkhead opposite the rod for connecting the cushioning device between two railway cars;
• a plurality of egress ports located within a portion of the cylinder wall between the piston and the bulkhead when the piston is in the extended position, the egress ports being located at various distances from the bulkhead;
• and
• a plurality of valve means, each coupled to at least one of the egress ports for allowing fluid to flow only in one direction through said egress ports from the cylinder to the reservoir in response to a selected fluid pressure differential within the cylinder;
• and wherein each of the valve means comprises:
• a body having a longitudinal axis which couples to the egress port;
• a valve piston slidingly mounted within the body and having an axial passage;
• a valve seat joined to the body, the valve seat being a frusto-conical recess;
• a frusto-conical shaped head joined to the valve piston which sealingly engages the valve seat for preventing fluid flow through the valve means;
• a plurality of valve ports extending through the head and joining the axial passage, the valve ports allowing fluid to pass through the axial passage of the valve when the head is unseated from the valve seat;
• and
• resilient biasing means for urging the head of the valve piston into engagement with the valve seat.

A valve in a cushioning device for absorbing impact between railway cars having a fluid recovery reservoir, a cylinder containing a mixed gas and liquid, the cylinder having a cylinder wall and being located within the reservoir, a bulkhead at one end of the cylinder and a cylinder head at the other end of the cylinder having a hole therethrough, a piston located within the cylinder which moves from an extended position to a contracted position, the piston having a rod extending through the hole for cushioning the impact, coupling means on the rod and the bulkhead opposite the rod for connecting the cushioning device between two railway cars, and a plurality of egress ports located within a portion of the cylinder wall between the piston and the bulkhead when the piston is in the extended position, the egress ports being located at various distances from the bulkhead, the valve coupled within at least some of the egress ports and being openable to allow fluid to flow only in one direction through said egress ports from the cylinder to the reservoir in response to a selected fluid pressure differential within the cylinder, the valve comprising:

• a body having a longitudinal axis which couples to the egress port;
• a valve piston slidingly mounted within the body and having an axial passage;
• a valve seat joined to the body, the valve seat being a frusto-conical recess;
• a frusto-conical shaped head joined to the valve piston which sealingly engages the valve seat for preventing fluid flow through the valve;
• a plurality of valve ports extending through the head and joining the axial passage, the valve ports allowing fluid to pass through the axial passage of the valve when the head is unseated from the valve seat;
• and
• resilient biasing means for urging the head of the valve piston into engagement with the valve seat.

In a cushioning device for absorbing buff and draft movement between railway cars having a fluid recovery reservoir, a cylinder containing a mixed gas and liquid fluid, the cylinder having a cylinder wall and being located within the reservoir, a bulkhead at one end of the cylinder and a cylinder head at the other end of the cylinder having a hole therethrough, a piston located within the cylinder which moves from an extended position to a contracted position, the piston having a rod extending through the hole for cushioning the buff and draft movement, coupling means on the rod and the bulkhead opposite the rod for connecting the cushioning device between two railway cars, and a plurality of egress ports located within a portion of the cylinder wall between the piston and the bulkhead when the piston is in the extended position, the egress ports being located at various distances from the bulkhead, the improvement comprising:

• a plurality of spring-biased pressure relief valves, each coupled within one of the egress ports, each of the pressure relief valves being openable to allow fluid to flow only in one direction through said egress ports from the cylinder to the reservoir in response to a selected fluid pressure differential between the cylinder and the reservoir due to buff and draft movement;
• and
• restoration valve means for allowing fluid to escape from the cylinder to the reservoir as the piston is moved to the extended position by a restoring force due to gas pressure, the restoration valve means closing in response to a second preselected pressure created by draft movement of the piston within the cylinder, the second preselected pressure differential being lower than the first pressure differential.