Railway rolling stock – Special car bodies – Dumping
Reexamination Certificate
2000-05-25
2001-07-10
Morano, S. Joseph (Department: 3617)
Railway rolling stock
Special car bodies
Dumping
C105S238100, C105S240000, C105S250000, C105S255000, C105S280000, C105S310000, C049S501000, C239S650000
Reexamination Certificate
active
06257150
ABSTRACT:
DESCRIPTION
This invention relates in general to a new and improved rapid discharge railcar door for railway coal cars, and more particularly to a rapid discharge coal car door made of a polymer formed in a reaction injection molding (RIM) process over an aluminum frame that significantly lowers the weight of the door to allow for more coal to be loaded in the railway car, and which provides sufficient strength and resistance to changes in temperature.
BACKGROUND OF THE INVENTION
Coal continues to be a prevalent source of energy, particularly for electric generating stations. Millions of tons of coal are transported by railway cars each year within the United States between a coal mine and a user facility. In order to maintain the condition of the railways and to insure safety, regulations are imposed to limit the total weight of each railway car. Currently, the total weight allowed for each railway car, including the weight of the car itself, is 286,000 pounds. As the coal companies obviously desire to ship the most amount of coal per railway car or ship a certain amount of coal with the least amount of railway cars, there has been a continuous effort to lower the weight of the railway cars while still maintaining the railway cars' structural integrity. However, one limiting factor in improving railway cars is the fact that as the coal is transported across the country, it may pass through various states and be subjected to various weather conditions. For example, when coal passes through sub-zero temperatures, it will freeze, and thus require the coal to be subjected to a thawing process. Thus, any components in the coal cars must be able to withstand the various stresses imparted upon them.
Heretofore, it has been known to use an aluminum door with a steel frame for rapid discharge coal car doors. The use of an all metal door, especially with a steel frame, results in a door having a weight of almost 190 pounds. Heretofore used all-steel doors are even heavier. Most coal cars are hopper cars with multiple outlets in the bottom selectively opened and closed by discharge doors. A commonly found hopper car has sixteen discharge doors working together in pairs to cover eight discharge outlets. The total weight of sixteen all-metal doors is over 3000 pounds, or about one percent of the total allotted weight per railway car.
Others have considered using certain plastics, such as polyurethane, as a substitute for the aluminum doors. However, such plastic doors generally would not withstand the heating the doors must be subjected to during the thawing process. Further, it is unclear whether doors made of regular polyurethane would have sufficient strength to adequately support the coal load and perform adequately as a rapid discharge coal car door.
SUMMARY OF THE INVENTION
The present invention is in a plastic door molded on an aluminum frame which overcomes the weight and temperature change problems of metal and other plastic doors. The door of the present invention is made from a polymer formed in a reaction injection molding (RIM) process. Polymers formed using a RIM process provide a light-weight and strong product that can withstand various stresses associated with coal loads and the changes in temperature and weather. It should also be appreciated that the door of the present invention may be used on any bottom dumping car carrying granular material, such as plastic pellets and the like.
Heretofore used aluminum doors with steel frames weighed about 190 pounds, as above mentioned, while the doors of the present invention molded of a RIM polymer over an aluminum frame weigh about 95 pounds. As there are sixteen doors per the hopper coal car above referred to, the doors of the present invention, which weigh about half as much as the aluminum doors, will reduce the weight of the car by over 1500 pounds. Trains carrying coal often have over 100 coal cars per train. Thus, the use of the doors of the present invention will allow over 150,000 additional pounds of coal per trip for a 100 car train.
In order to prevent any occurrence of hanging coal, a liner is placed over the side of the door engaging the coal to provide for a non-stick surface. One satisfactory material for use in the liner is a black UV resistant ultra-high molecular weight polyethylene (UHMWPE).
It is therefore a primary object of the present invention to provide a rapid discharge coal car door that will be lighter than an aluminum and steel door, thereby reducing the overall weight of a hopper coal car and allowing more coal to be transported per car and per a train of coal cars.
Another object of the invention is to provide a rapid discharge door for bottom dumping railcars carrying granular materials that will be lighter than an aluminum and steel door, thereby reducing the overall weight of the railcar and allowing more granular material to be transported.
Another object of the present invention is to provide a rapid discharge coal car door that provides adequate strength against load-bearing forces and which can withstand changes in the weather and the thawing process needed to thaw frozen coal.
A further object of the present invention is to provide a rapid discharge coal car door having a longer life than heretofore known doors and that will eliminate hanging coal heretofore encountered on steel and aluminum doors, thus allowing the coal car to fully discharge the coal.
Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts.
REFERENCES:
patent: 3658596 (1972-04-01), Osborne
patent: 4155200 (1979-05-01), Emanuel
patent: 4278382 (1981-07-01), Knippel
patent: 5426894 (1995-06-01), Headrick
patent: WO9915358 (1999-04-01), None
patent: WO99/15358 A1 (1999-04-01), None
Jules Frantz F.
Morano S. Joseph
Zeftek, Inc.
Zickert Lloyd L.
LandOfFree
Rapid discharge railcar door does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rapid discharge railcar door, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rapid discharge railcar door will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2558293