The present invention relates to a switching assembly for a railway switch and rail arrangement. A railway switch is employed where one track diverges from another. This invention relates to a switch point guard casting for use adjacent the switch point of railway switches in trackwork.
Typically, railroad switching components are some of the highest maintenance portions of a railroad track arrangement as they must endure repetitive impact and stress, as well as extreme inertial forces attendant to lateral disposition of the running wheels and the loads they bear.
The switching rail of a railway switch assembly includes a tapered rail portion which terminates into a thin end point for intercepting and switching the wheels of rolling stock from one rail onto another.
Because such switch point guards engage the wheel flanges at an angle and urge the wheel toward a new route as it proceeds through the switch region, they experience considerable wear due to the repeated contact between the moving wheels and the wheel engaging surface of the guard rail. These castings are designed to capture the wheel and direct it through the switching zone.
In prior art arrangements, switch point guards used a simple, straight lateral surface to urge the wheels into and through their required course through the switching region. In such arrangements, such switch point guards also carried the risk of derailment because their lateral surfaces rub against the engaging wheel and can cause the wheel to ride up the lateral surface, which may lead to a raising of the wheel through a ramping effect as the side of the wheel creeps up the side of the casting. This causes either violent re-leveling of the wheel as the friction of the wheel against the casting gives way to gravity (leading to repetitive impact events that wear the track work and wheels alike) or, in extreme cases, to derailment should the wheel be raised to a point where it loses the capture of the wheel flange.
It is also best to provide a uniform, secure wheel path that distributes load and reduces wheel and guard wear, while reducing the risk of wheel ride-up and derailment.
The embodiments of the invention described herein address the shortcomings of the prior art.