Railway ballast excavator having inclined portion

Abstract

A railway ballast excavating apparatus comprising a guide frame having an endless excavating chain mounted thereon, the guide frame having a first portion for insertion beneath the railway tracks and a second portion parallel and inclined with respect to the first portion, the first portion for excavating ballast and the second portion for elevating the excavated ballast in order to deposit the excavated ballast in a pile adjacent the railway tracks. The apparatus is powered by a rubber-wheeled motive vehicle and can be advantageously lifted from the railway tracks in the event of an oncoming train.

Description

FIELD OF THE INVENTION [0001] The invention relates to the excavation of ballast from beneath railway tracks and the simultaneous elevation and piling of excavated ballast alongside the railway track. More particularly, the invention relates to an apparatus and method of excavating railway ballast for the purpose of repairing small sections of track using a mobile endless-chain type excavator having a horizontal portion for excavating the ballast and an inclined portion for elevating the excavated ballast. BACKGROUND OF THE INVENTION [0002] Railway lines generally comprise a set of spaced apart rails mounted on a plurality of transversely placed railway ties that are located upon a bed of compacted ballast material. The rails, ties and ballast must be routinely replaced and machines for removing, cleaning and replacing ballast, such as described in U.S. Pat. No. 5,090,484, are known in the art. However, these machines are large and not particularly well suited to removing ballast fr...

AI Technical Summary

Benefits of technology

[0017] In the prior art, excavated material quickly accumulates in the vicinity of the outward end of the guide frame, which interferes with the rate of excavation, increases the likelihood for damage to the apparatus, and limits the amount of material that can be removed in each transit of the apparatus along the tracks. To overcome these disadvantages, the present invention is equipped with a first portion and a second portion that is parallel to the first portion but inclined thereto. This second portion serves to elevate the excavated material and deposits the excavated material in a pile alongside the railway track. The angle of inclination in some part depends upon the amount of material desired to be removed in a single transit of the apparatus along the tracks. If the full width of the tracks is to be excavated in a single transit (which normally results in a first portion length in excess of 13 feet), then a greater angle may be required as compared with an excavating unit having a shorter first portion. However, larger inclination angles have the disadvantage of losing more of the excavated material while elevating, causing the pile to be spread out alongside the tracks and generally reducing the efficacy of the second portion. It has surprisingly been found that only a small angle is required for proper pile formation, even during full-width cutting operations. The second portion may be inclined with respect to the first portion at an angle of from 10 to 45 degrees, preferably from 15 to 30 degrees, more preferably from 20 to 23 degrees, yet more preferably about 22 degrees.

[0018] A further benefit of using the smallest allowable inclination angle is found in the excavating chain. Since the excavating chain is required to deflect upwardly as it travels from the first portion to the second portion, the excavating chain may be provided with one or more universal joints between each link. The universal joints may comprise a semi-spherical eye within a complementary bearing race that permits the normally vertical pivot axis between each link to deflect to an angular orientation as the joint passes from the first portion to the second portion. As the inclination angle of the second portion

Problems solved by technology

However, these machines are large and not particularly well suited to removing ballast from relatively small sections of track or for repairing a portion of a track.

This apparatus is limited in that ballast material can only be excavated from the immediate vicinity of the excavating vehicle and, since these vehicles are quite heavy, this can cause track instability resulting in misalignment and the need for extensive repair.

This spreads the material around in the vicinity of the tracks, making it difficult to collect and remove at a later time.

Although the apparatus is suited for small track repairs, the apparatus cannot be operated continuously along a small section of track, such as a siding.

The excavated material accumulates behind the apparatus; the material must therefore be dislodged as the apparatus is removed, with the disadvantages described above, and driven over by the forklift vehicle as the apparatus is advanced beneath the track.

The apparatus is not suitable to continuous operation along a small

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