Railcar door operating mechanism with piston lock

A railcar door operating mechanism with piston lock used for opening, closing and locking a railcar door. The railcar door operating mechanism may include a hydraulic piston, a piston lock, a lock drive, and a lock drive piston. To open a railcar door the lock drive piston extends and causes movement of the lock drive. The lock drive then engages the piston lock and moves the piston lock from a locked position to an unlocked position. Once the piston lock is in an unlocked position, the hydraulic piston is then retracted to open the railcar door. To close the railcar door, the hydraulic piston is again activated extending the hydraulic piston to close the railcar door. The lock drive piston may then retract and cause movement of the lock drive. The lock drive may again engage the piston lock and move the piston lock into a locked position.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates generally to a mechanism for opening, closing and locking railcar doors, and more specifically to a mechanism for opening, closing and locking rapid discharge railcar doors located on or near the bottom of a railcar.

2. State of the Art

A common type of railroad freight car used today is an open-top hopper car wherein the commodity carried by the railcar is discharged through an opening provided on the underside of the car. Such cars are used to haul aggregate, iron ore, coal and other commodities. Such cars offer an advantageously economical method of transporting large amounts of a commodity between locations.

Conventionally, when a hopper car arrives to deliver its load, technicians open its doors. The conventional way to open the door is by striking the railcar door latch in an upward direction with a large sledgehammer. For each door, there is a latch at each side of the door (two latches per door set). The striking motion must be accurate for each latch to move to the open position. Often, it takes multiple strikes of a hammer to release each latch, allowing the doors to open and dispatch the material.

The technician opening the door in this conventional way is exposed to many hazards. The surface he is standing on, through which the transported commodity falls, is generally a grate of various dimensions of spacing; an estimated average is an opening of approximately six inches square. The grate is necessary for the material to flow through to a storage container or hopper located under the grate. The grate creates a hazard for the technician, and the industry has experienced an unacceptably large number of accidents related to human extremities slipping through the grate while technicians open the doors. Additionally, strikes missing the latches while attempting to deliver strikes powerful enough to move the latches can result in the technicians loosing their balance, falling and sustaining various other injuries.

To close the doors, the technician again stands on the grate through which the material flows. While on this grate, the technician is required to insert a heavy steel bar through a rung on the car hopper door, and then pry the door up to the latch of the railcar door. This action is repeated for each side of each door set. When the hopper doors are bent or out of square, which is common because the doors are generally opened one side at a time causing torsional stresses on the door from the weight of the commodity above the door, the technician is required to use additional force to bend the doors closed. This action while standing on the grate creates additional hazards for the technicians, and the industry has experienced an unacceptably large number of accidents related to human extremities falling through this grate while technicians close the doors. Many back injuries are also sustained.

Accordingly, what is needed is a mechanism that will open and close a railcar door with limited or no technician intervention and will replace the currently difficult and dangerous to operate door latches.

DISCLOSURE OF THE INVENTION

The present invention relates to a mechanism for opening, closing and locking a railcar door. Embodiments of the invention provide a railcar door operating mechanism with a piston lock that is coupled to an existing railcar to serve as the opening, closing and locking device of the railcar door. The system is intended to replace current devices that open, close and lock railcar doors.

In a particular embodiment, the railcar door operating mechanism includes a hydraulic piston, a piston lock, a lock drive, and a lock drive piston. To open the railcar door, the lock drive piston extends and causes movement of the lock drive. The lock drive engages the piston lock and moves the piston lock from a locked position to an unlocked position. Once the piston lock is in an unlocked position, the hydraulic piston is activated. The hydraulic piston is retracted and the railcar door is opened, thereby allowing the dumping of the commodity being transported within the railcar. After the railcar is emptied, the hydraulic piston is again activated, whereby the hydraulic piston is extended and the railcar door is closed. The lock drive piston then retracts and causes movement of the lock drive. The lock drive again engages the piston lock and moves the piston lock into a locked position.

Additionally, in other particular embodiments, the railcar door operating mechanism includes a hydraulic piston, a piston lock/lock drive combination, a piston stop and a lock drive piston. In these particular embodiments the piston lock and lock drive may be combined into a single component, which engages the piston stop in order to lock the railcar door in a closed position.

The railcar door operating mechanism with piston lock may be used individually for each railcar door, or it may be used in conjunction with a plurality of mechanisms to provide the sufficient force necessary to operate that particular railcar door.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

As discussed above, embodiments of the present invention relate to a mechanism for opening, closing and locking a railcar door. Embodiments are particularly useful for railcar configurations wherein the railcar doors are underneath the railcar and are difficult to operate safely. Embodiments of the railcar door operating mechanism of the present invention may be coupled to an existing railcar to serve as the opening, closing and locking device of the railcar door, thereby replacing current devices to performs such tasks. Alternatively, embodiments of the railcar door operating mechanism may be incorporated into new railcars.

As shown inFIG. 1, a railcar door operating mechanism10may be coupled to a railcar30at a frame portion32and at the railcar door34by use of doorplate36. It will be understood by those of ordinary skill in the art that a plurality of mechanisms10may be coupled to a railcar30dependent upon the number of railcar doors34on a particular railcar30. It will also be understood that while in particular embodiments of the present invention one mechanism10may be used for each railcar door34, that a plurality of mechanisms10may be employed on each railcar door34. Additionally, various sizes of mechanisms may be employed on a railcar30dependent upon the required force needed to open the railcar door34.

Generally, a particular embodiment of the operating mechanism10, as shown inFIG. 1, operates a hydraulic piston to open the railcar door34and dump the load carried by the railcar30out of the bottom of railcar30. When the load is emptied, the operating mechanism10then closes the railcar door34and locks it in closed position. This locking of the operating mechanism10is used in place of conventional latches that retain the railcar door34in a closed position. The operating mechanism10remains locked even in situations where there is a loss of power, such as, but not limited to a loss of hydraulic pressure.

With reference toFIG. 2, a close-up view of operating mechanism10of the present invention is shown coupled to railcar30. According to a particular embodiment of the invention, the operating mechanism10comprises a hydraulic piston12, a piston lock18, a lock drive20and a lock drive piston26. In the particular embodiment shown inFIG. 2, the hydraulic piston12comprises a barrel14and a rod16and the lock drive20comprises a hinge pin21, a lift guide22, a connecting rod23and a lock guide24. However, it will be understood by those of ordinary skill in the art that the lock drive20may incorporate any type of movement, such as but not limited to pivoting, rotating, linear translation and the like. It will also be understood that the lock drive20may also comprise a fork, a ring, a collar, a collet, a four-bar mechanism, a moveable apparatus, and any combination thereof, which can transfer its movement into the movement of the piston lock18. The operating mechanism10may be coupled at the barrel14to a frame-plate38, whereby the frame-plate38is coupled to a frame portion32, or the barrel14may be coupled directly to the frame or other existing structure on the railcar to provide proper placement of the operating mechanism10. The operating mechanism10may also be coupled to a doorplate36, the doorplate36being coupled to the railcar door34.

According to a particular embodiment of the present invention, the operating mechanism10is shown inFIG. 2with the railcar door34in a closed position. To maintain railcar door34in a closed position for this embodiment, hydraulic piston12is extended, wherein the rod16is extended out of the barrel14. The piston lock18is in a locked position preventing hydraulic piston12from moving into an open position and opening railcar door34. The lock drive piston26is in a first position, thereby rotating lock drive20into a first position, such that lock guide24engages the piston lock18and retains the piston lock18in a locked position. It should be appreciated by those of ordinary skill in the art that the operating mechanism10will remain locked, keeping the railcar door34closed, even if hydraulic pressure is lost in the hydraulic piston12and lock drive piston26. WhileFIG. 2shows the operating mechanism10in a closed position with the hydraulic piston12in an extended position, the operating mechanism10may also use a retracted position to hold the railcar door34in a closed position, wherein the rod16is retracted within the barrel14. In such cases, the operating mechanism10may be oriented such that the hydraulic piston12is coupled to a frame portion of the railcar30on a side of the railcar door34such that the railcar door34opens away from the operating mechanism10. Additionally, the lock drive piston26may be in an extended position in order to retain piston lock18in a locked position. For example, the lock drive piston26may be coupled to the railcar door34while the remaining components of the operating mechanism10are oriented as shown inFIG. 2, thereby requiring the lock drive piston26to be extended to retain piston lock18in the locked position.

Referring now toFIGS. 3 and 4, the operating mechanism10is shown with the piston lock18in an unlocked position and the entire operating mechanism10in an open position respectively. To unlock the embodiment of the operating mechanism10shown inFIGS. 3 and 4, lock drive piston26is moved to a second position, thereby rotating lock drive20into a second position. While the lock drive20rotates, lift guides22direct the piston lock18from its locked position to an unlocked position free from interference with hydraulic piston12. The hydraulic piston12is then activated and moves into an open position. The lock drive piston26stays extended and the lock drive20stays rotated in the second position wherein the piston lock18is resting on the lift guides22. As the hydraulic piston12moves into the open position, the piston lock18travels with the movement of rod16while the lift guides maintain a proper clearance of the piston lock18, free from interference of the barrel14or any other part of the hydraulic piston12. This movement into an open position of the hydraulic piston12opens the railcar door34and allows commodity within the railcar30to be unloaded.

After the commodity is unloaded, the operating mechanism10may then go through a reverse process whereby the hydraulic piston12is moved into a closed position to close the railcar door34. When the hydraulic piston12reaches its fully closed position, determined by the closing of the railcar door34, the lock drive piston26is activated and moves into the first position, rotating the lock drive20into the first position. As the lock drive20rotates, the lock guide24directs the piston lock18through its rotation into a locked position, and retains the piston lock18in a locked position. It will be recognized by those of ordinary skill that while particular embodiments of the present invention show that opening of the railcar door34accomplished by the retracting of the hydraulic piston12and the closing of the railcar door34accomplished by the extending of the hydraulic piston12, other embodiments may be adapted such that the extending of the hydraulic piston12opens the railcar door34and the retracting of the hydraulic piston12closed the railcar door34. In such cases, the operating mechanism10may be oriented such that the hydraulic piston12is coupled to a frame portion of the railcar30on the opposing side of the railcar door34such that the railcar door34opens away from the operating mechanism10.

Referring toFIGS. 5-7, particular embodiments of the present invention may include an operating mechanism10comprising a hydraulic piston12, a piston lock18, a lock drive20, a lock drive piston26, frame-plates28and38and a doorplate36. Further, the hydraulic piston12may comprise a barrel14and a rod16. The barrel14may comprise a seat15and the piston lock18may comprise a corresponding protrusion19, such that when the piston lock18is in a locked position, the protrusion19is pressure fit into the seat15thereby impeding easy unlocking of the piston lock18. The use of a seat15associated with a protrusion19is not fundamental to the functioning of the operating mechanism10, but may be employed to reduce the risk of accidental release and unintentional unlocking of the piston lock18. The use of seat15and protrusion19may also be used as a trigger to determine when the piston lock18is fully in place, so as to stop the activation and movement of the hydraulic piston12and the lock drive piston26. Additionally, the piston lock18may comprise a channeled, lever arm that provides for an over-center lever to lock the hydraulic piston on opposing sides of the rod16for a more efficient locking scheme. As will be understood by those skilled in the art that other components that perform the same functions may be used and perform equally well.

It should be specifically understood by those of ordinary skill that while shown to share the same pivot point as that of the rod16, the piston lock18may have its own independent pivot point without compromising the functionality. The piston lock18is not limited to a channeled lever arm, but may also be a solid piece or a partial channel. The piston lock18may also be off-center while still providing the same locking ability on hydraulic piston12. Also, while the piston lock18is shown to be a lever arm, it may be any type of piston lock with any type of movement and is not limited to pivoting, such as, but not limited to a fork, a ring, a collar, a collet, a chuck, a pin and any other part type that is moveable between a locked and an unlocked position.

The lock drive20may comprise a lift arm. The lock drive20shown inFIGS. 5-7comprises lift guides22, a lock guide24and a connecting rod23to connect to the lock drive piston26. The lift guides22are shown as knobs that are used to lift the piston lock18, however, they may be adapted to aid in the movement of the piston lock18dependent upon the type of movement piston18requires to move between a locked and an unlocked position. The lock drive20may also comprise one of a fork, a ring, a four-bar mechanism, a collar, a collet, a cam and any combination thereof wherein the lock drive20is moveable between a first and second position. The first position is associated with the locked position of the piston lock18and the second position is associated with the unlocked position of the piston lock18.

The lock guide24is shown inFIGS. 5-7as a loop that is of the size and shape to receive the piston lock18. The lock guide24is not limited to this type of loop as shown inFIG. 7, but may be of any shape, size or design, so long as the lock guide can provide the necessary force to move the piston lock18into a locked position.

It will be understood that while the lock drive20may be operated by use of the lock drive piston26, that it may also be operated manually. The lock drive may also be operated using a pneumatic piston, an air-powered quick release, a reversible magnetic loop and any other form of providing movement to the lock drive20. Additionally, it may be coupled to the hydraulic piston12at the barrel14or directly to the railcar, to the rod16, the piston lock18or any other part whereby the lock drive20may operate the piston lock18. It will also be understood that the lock drive20and therefore the piston lock18may be inverted such that the lift guides22push the piston lock down to the unlocked and the lock guide24lifts the piston lock18into the locked position.

As shown inFIGS. 8 and 9, particular embodiments of the present invention may also include railcar door operating mechanism40. The operating mechanism40may comprise a hydraulic piston12, which may include a barrel14and a rod16, a piston lock/lock drive42, a piston stop44coupled to the rod16and a lock drive piston26. In order to retain railcar door34in a closed position, hydraulic piston12may be moved to an extended position, wherein the rod16extends out of the barrel14. The lock drive piston26may be in a retracted position, thereby keeping the piston lock/lock drive42in a rotated closed position. While in the closed position, the piston lock/lock drive42may engage piston stop44and prevent the hydraulic piston12from retracting and opening the railcar door34. To open the railcar door, the lock drive piston26may be extended to rotate the piston lock/lock drive42into an opened position. With the piston lock/lock drive42out of the way, the hydraulic piston12may then be retracted to open the railcar door34. It should be understood by those of ordinary skill in the art, the piston lock/lock drive42may be of any shape and size so long as the piston lock/lock drive42may be moved into a closed position to lock the hydraulic piston12in its closed position and to into its opened position to permit the retraction of hydraulic piston12.

The piston lock/lock drive42combination may be of any shape and size to accommodate the amount of travel necessary to fully open the railcar door. It should be appreciated that while the particular embodiment shown inFIGS. 8 and 9show the hydraulic piston12in an extended position to close the railcar door and in a retracted position to open the railcar door, that the hydraulic piston12may utilize a retracted position to close the railcar door and an extended position to open the railcar door as explained earlier.

The piston stop44may comprise a ring, a collar, a collet, an annulet, or any other structure that may be used as a stop for inhibiting movement of the hydraulic piston12. Additionally, the piston stop44may be coupled to the rod through means such as, but not limited to, a weld, a bolt, a screw and an epoxy or the piston stop44may integral to the rod16or integral to the barrel14. The piston stop44may also be coupled to the frame of the railcar or to the railcar door, so long as the piston lock/lock drive42can engage the piston stop44and stop movement of the hydraulic piston12.

As shown inFIGS. 10-13, particular embodiments of the present invention may also include a railcar door operating mechanism50. The operating mechanism50may comprise a hydraulic piston12with a barrel14and a rod16, a piston lock52, a collar60, lock bearings56, bearing retainers62, a notch58, a lock drive54and a lock drive piston26. The piston lock52may be a cylindrical sleeve with a tapered inner diameter. To retain hydraulic piston12in an extended position, lock drive piston26may be in an extended position thereby moving the lock drive54into a closed position. As the lock drive54moves into a closed position, it engages the piston lock52and moves it into a locked position. As the piston lock52moves into a locked position, the lock bearings56are compressed within the notch58by the tapered inner diameter of piston lock52. The collar60and bearing retainers62ensure that the lock bearings56are properly placed within the notch58. The compression of the lock bearings56in the notch58inhibits any movement of the hydraulic piston12, thereby retaining it in a locked position. To place the hydraulic piston12in an unlocked position, the lock drive piston26may retract causing the lock drive54to move into an opened position. When in moving into an opened position, the lock drive54engages the piston lock52and moves the piston lock52into an unlocked position. The movement of the piston lock52into an unlocked position places the larger inner diameter of the tapered inner diameter of the piston lock52around the lock bearings56, thereby freeing the lock bearings56from the notch58and allowing the lock bearings to be retained within the bearing retainers62. This places the hydraulic piston12into an unlocked position and the hydraulic piston12may then be retracted.

It should be appreciated that while the particular embodiment shown inFIGS. 10-13show the hydraulic piston12in an extended position to close the railcar door and in a retracted position to open the railcar door, that it the hydraulic piston12may utilize a retracted position to close the railcar door and an extended position to open the railcar door. The operating mechanism50may be oriented such that the hydraulic piston12is coupled to a frame portion of the railcar30on a side of the railcar door34such that the railcar door34opens away from the operating mechanism10

It will be understood by those of ordinary skill in the art from the disclosure provided that while one lock drive piston26is shown per door for each of the various embodiments herein, that there may be a plurality of lock drive pistons20used to operate the piston lock52. It will also be understood while lock bearings56being pressed into a notch58is shown as the method of locking the hydraulic piston12, that other methods may be employed, such as the use of a lock washer, a shaft and hole and other methods known to restrict the movement of a hydraulic piston12.

The embodiments and examples set forth herein were presented in order to best explain the present invention and its practical application and to thereby enable those of ordinary skill in the art to make and use the invention. However, those of ordinary skill in the art will recognize that the foregoing description and examples have been presented for the purposes of illustration and example only. The description as set forth is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the teachings above without departing from the spirit and scope of the forthcoming claims. For example, while particular embodiments employ hydraulic pistons, the operating mechanism may also use pneumatic pistons, electrical actuators, any type of air or fluid piston and any combination thereof.

While the present invention has been shown to be hydraulically operated, it may also be manually operated. In such cases, the need for a lock drive and a lock drive piston may be eliminated. Additionally, the railcar door operating mechanism with piston lock may be operated automatically or semi-automatically as a railcar approaches an unloading station, whereby the system may be activated using a magnetic loop, a remote control, an on-train controller, an off-train controller or other method of starting the hydraulic flow of the system operating mechanism. The hydraulic pump may also be located on-train or may be a wayside pump.

The frame plates28and38and the doorplate36may be coupled to a portion of the frame and the railcar door respectively by use of, but not limited to, welds, epoxy, bolts, clamps, and other binding methods that have sufficient strength to resist failure under the loads of opening and closing the railcar door with and without a commodity loaded in the railcar. It should be understood that the operating mechanism10is functional even with loose impediments that may be present to inhibit the closing of the railcar door34.

The operating mechanism10is shown in use with railcar doors located on the bottom side of a railcar30, the railcar doors34being of the type of a rapid discharge door that functions using two separate doors that pivot open in opposite directions. It should be understood that the operating mechanism10, according to particular embodiments of the present invention may used on various door types that are located on the underneath the railcar30.