Railway rolling stock – Special car bodies – Dumping
Reexamination Certificate
2000-07-18
2002-04-02
Morano, S. Joseph (Department: 3617)
Railway rolling stock
Special car bodies
Dumping
C105S254000, C105S282200, C105S294000, C105S305000
Reexamination Certificate
active
06363863
ABSTRACT:
FIELD OF THE INVENTION
The present invention generally relates to railroad hopper cars which transport and releasably hold food grade materials therein and, more particularly, to a gate assembly for a railroad hopper car which allows such food grade materials to be discharged from the hopper car either pneumatically or gravitationally.
BACKGROUND OF THE INVENTION
Railroad hopper cars typically include an underframe for supporting a walled enclosure in which bulk materials are held and transported. As is conventional, the underframe of the railroad car is supported toward opposite ends by well known wheeled trucks which ride on tracks or rails. A bottom of the walled enclosure is usually provided with two or more individual openings for allowing bulk materials to be discharged from the walled enclosure. The walled enclosure of the railroad car furthermore typically includes sloped or slanted walls or sheets angularly extending upwardly from a periphery of each opening to promote gravitational movement of the bulk material toward the opening.
In the prior art, combination gravity and pneumatic gate structures have been provided which permit the discharge of material from the walled enclosure of a hopper car either by gravity or pressure differential such as vacuum. Such a gate structure typically includes a frame arranged in registry with an opening on the hopper car and a gate which is positioned beneath the opening on the hopper car for movement along a predetermined path of travel. The gate is typically mounted for sliding movement on the frame between open and closed positions. Most gate assemblies include a gate drive mechanism typically in the form of an operating shaft assembly extending laterally across one end of the gate assembly for operationally moving the gate between open and closed positions. In most gate designs, the operating shaft assembly combines with a rack and pinion assembly to move the gate depending upon the rotational direction of the operating shaft assembly. In some gate designs, such a rack and pinion assembly includes a pair of elongated stationary racks projecting in parallel relation relative to each other away from the frame and which intermesh with pinions mounted on the operating shaft assembly. The pinions on the operating shaft assembly are operably connected to and move with the gate. When in an open position, the gate allows the commodity to gravitational pass and be discharged from the hopper car.
At the railroad car unloading station, a powered driver is moved into driving engagement with one end of and turns the operating shaft assembly. As such, the pinions move along the stationary racks, thus, moving the gate therewith. As is conventional, the drivers which impart rotational movements to the operating shaft assembly are mounted on wheels and are readily movable in a direction extending generally parallel to a longitudinal axis of and are movable toward and away from the operating shaft assembly, as required. Such drivers, however, are typically not designed or configured to move sideways along with the gate. Accordingly, as the operating shaft assembly is rotated, the driver is forcibly pulled along in a direction opposed to its natural direction in which the driver moves thereby adding to the forces which must be overcome in moving the gate along its predetermined path of travel.
In the event pneumatic discharge of material is desired, a pan element is positioned underneath the discharge opening and below the gravity gate. Typically, the pan is provided with an open ended outlet tube for discharging the material from the hopper car. The pan is typically fastened to the walled enclosure of the hopper car as with a plurality of fasteners. As will be appreciated, however, valuable time is consumed and lost by having to affix and remove the pan from the hopper car depending upon whether a gravitational discharge mode or a pneumatic mode of discharge is to be used to unload the hopper car. Mounting the pan element beneath or under the gate also reduces the clearance between the bottom of the gate assembly and the railbed over which the car travels between locations. As will be appreciated by those skilled in the art, the degree of clearance between the underside of the gate assembly and the railbed is a serious concern when designing discharge gate assemblies for hopper cars coupled with customer pressures to increase the volumetric payload for the railroad car.
Mounting and arranging the pan element above the sliding gate of the gate assembly has not proven feasible for several reasons. Mounting and arranging the pan element above the sliding gate of the gate assembly has been found to obstruct the flow of material from the walled enclosure in a gravitational mode of material discharge. Mounting the pan element above the gate also presents a problem involving keeping exhaust tubes extending from the pan element clean during loading of the commodity into the hopper car. Furthermore, the moisture in the commodity, tends to cause mold, mildew and other contaminants to be present within outlet tubes leading from the pan element.
The open end of the outlet tube presents still further problems involving railroad hopper car gate assemblies. As will be appreciated, and during transport of the railcar between locations, the outlet tube presents a conduit for directing debris to an interior of the pan assembly. Various devices have been proposed for closing the free open end of such outlet tubes. Such devices, however, often become separated from the outlet tube and are lost. Moreover, the capability of such devices to adequately seal the free open end of the outlet tube is limited. The mechanisms used to secure such known devices to the free end of the outlet tube furthermore add to problems involving timely opening of the discharge tube when pneumatic unloading is the desired means for unloading the railroad hopper car.
Movably mounting a pan element on the frame of the gate assembly beneath the gate introduces significant design problems. First, mounting a pan element for movement beneath the gate requires a second drive mechanism which, most likely, will include another or second operating shaft assembly along with a rack and pinion assembly. As will be appreciated, providing a second drive mechanism for moving the pan element relative to the frame structure of the gate assembly seriously complicates the gate design in several respects. First, the provision of two independently operable drive mechanisms complicates the process for emptying the lading from the hopper car. Second, spacial requirements for the gate assembly, especially when considering the drive mechanism for moving the gate between open and closed positions, is severely restricted. Providing an additional or second drive mechanism on the frame of the gate assembly for moving the pan element between open and closed positions can further adversely effect the clearance required between the gate assembly and the railbed. Of course, if the gate assembly does not provide proper clearance significant damage can result to the gate assembly and the car as the railcar moves between locations. Simply raising the gate assembly, however, reduces the potential volumetric payload capacity of the car while also raising the railcar's center of gravity. Moreover, the addition of a second drive mechanism complicates the direction in which each drive mechanism is to be turned or rotated to effect movement of a particular element on the hopper car gate assembly.
The transportation and unloading of finely divided materials, and particularly food stuffs, such as sugar, flour and the like within and from the walled enclosure of the hopper car exacerbates the problems involved with the design and engineering of a railroad hopper car discharge gate assembly. When the material to be transported involves food stuffs, the FDA has promulgated certain rules and regulations which must be met in order for the hopper car to qualify for transporting foods stuffs. Of course, one of the paramount concerns inv
Harbst John W.
Jules Frantz F.
Miner Enterprises Inc.
Morano S. Joseph
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