Trolley system for a railway boxcar door

Abstract

A trolley system for positioning the door of a railway boxcar to cover or uncover an opening in a wall of the boxcar has an upper track mounted to the boxcar and an upper trolley with at least one roller rotatably secured therein and co-acting with the upper track. A safety plate restricts the vertical motion of the roller to prevent derailment of the trolley from the track. The safety plate may include various designs to maximize the retention of the wheel against the track. A boxcar utilizing either a simple sliding door or a sliding door having a plug-type door associated with it may utilize this trolley system.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application No. 60 / 457,416 filed Mar. 25, 2003 and U.S. Provisional Application No. 60 / 494,534 filed Aug. 12, 2003, which are hereby incorporated by reference in their entirety.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The subject invention relates to railroad cars and, more particularly, to a trolley system for positioning the door of a railway car. [0004] 2. Description of Related Art [0005] Railway boxcars typically include sliding doors which are doors which roll along a track to cover and uncover a similarly-shaped opening within the boxcar. Plug-type doors are similar to sliding doors because they roll along a track on the boxcar to cover or uncover an opening within the railway boxcar. However, plug-type doors additionally move axially in and out relative to the wall of the boxcar to not only cover the opening, but, furthermore, to seal the opening....

AI Technical Summary

Benefits of technology

[0010] In one embodiment of the subject invention, a trolley system for positioning the door of a railway boxcar to cover or uncover an opening in a wall of the railway boxcar opening has an upper track mounted upon the railway boxcar and an upper trolley having a body with at least one roller rotatably secured therein, wherein the at least one roller of the upper trolley co-acts with the track. A safety plate is connected to the railway boxcar and positioned above and adjacent to the at least one roller of the upper trolley, wherein the plate physically limits the vertical movement of the roller in the upper trolley to prevent derailment of the upper trolley from the upper track.

Problems solved by technology

Unfortunately, this design does not meet the current needs of industry.

For example, occasionally the plug door becomes stuck and a forklift truck must be used to overcome this resistance and position the plug door.

However, the force imparted by the fork lift tends to bend and damage the door.

Additionally, racks which are transported in and out of the boxcar tend to hit and damage the door.

Furthermore, the door becomes stressed from continual opening and closing.

As a result, over time the door and the door support mechanism become stressed and the mechanism becomes more difficult to operate.

Additionally, the plug door is operated by a crank mechanism and when the door support mechanism becomes difficult to operate, the crank mechanism may also be difficult to operate.

In some instances, fork trucks and racks may hit the inside of the door causing pins within the door support mechanism to shear which, in turn, may cause the door to fall from the boxcar.

While this problem has been described in relation to plug doors on railway boxcars, it should be appreciated that similar problems exist with simple sliding doors on railway boxcars.

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