Hi-rail vehicle

Abstract

The invention to a hi-rail vehicle for normal travel along a highway and selective travel along railway tracks provided with a first paid of railway track engageable wheels moveable between a normal position out of engagement with a railway track and a position of railway track contact immediately in front of the front steering wheels of the vehicle for guiding the vehicle; and second pair of railway track engageable wheels movable between a normal position between the forward and rear drive wheels with a railway tracks and a position of guiding contact therewith.

Description

FIELD OF THE INVENTION

The present invention relates to vehicle construction and more particularly to a vehicle capable to traveling on railroad track or highway.

BACKGROUND OF THE INVENTION

Part of the ongoing cost and responsibility of the continuing operations of any rail system is the maintenance of the infrastructure. There are two approaches to the provision of ongoing maintenance: developing an in-house maintenance organization or contracting those services out to firms specializing in such work. In a railroad environment there are needs for both routine transportation of the staff overseeing the daily operations and for the work equipment to perform the corrective and preventative maintenance functions.

The railroads of today, as with any infrastructure-based industry, have developed a unique set of highly specialized equipment for the performance of maintenance functions. The procurement of such specialized equipment not only requires a substantial initial capital investment, but also is paired with the need to provide those individuals trained to operate, repair and maintain that equipment.

In a railroad environment there is the need for transportation and maintenance equipment that is not found in other transportation fields such as the highway, marine, or air travel industries. Special vehicles are required to provide rail-borne access to locations along the right-of-way that may not be accessible to standard highway vehicles.

For both inspection of the right-of-way and for general rail-borne access, it is common practice to equip normal highway vehicles with “hi-rail” gear. This equipment is mounted to the frame of the vehicle front and back and consists of a set of steel wheels found on railroad rolling stock. This hi-rail gear is retractable and enables the vehicle to operate either on roads or on the rails of the track via the steel wheels. To operate on a railroad track a hi-rail equipped highway vehicle is typically positions longitudinally over the track at a grade crossing or other area where the roadway surface is approximately level with the top of the rails. The hi-rail gear is lowered into position, which raises the vehicle's front steering wheels off of the crossing surface and raises the rear wheels slightly to allow the weight of the vehicle to bear on the steel wheels of the hi-rail gear. The vehicle is then ready to proceed. The hi-rail gear allows the steel wheels to ride along the rails, and the rear rubber tires, which are still in enough contact with the rail to provide traction and propel the vehicle. In the same manner heavy construction vehicles ranging from cranes to dump trucks can also be fitted with hi-rail gear to provide access to the railroad right-of-way by means of the rails.

Besides the hi-rail equipment there are also numerous pieces of maintenance equipment manufactured specifically for work on the railroads. These range from ballast tampers that are used to consolidate and stabilize the track bed, to equipment used to handle crossties. These are all highly specialized, often single-function pieces of equipment, and their maintenance and procurement represent a significant portion of every railroad's capital expenditures.

There is an acknowledged need to be able to provide hi-rail access to portions of the proposed right-of-way that may not be accessible to highway vehicles. It is assumed that there would be a fleet of vehicles provided for the personnel assigned to the management of a rail system. The number and type of vehicles to be provided and the means of doing so (purchase or lease) would be determined once staffing issues are resolved.

The installation of hi-rail equipment represents a relatively small capital investment and will provide unrestricted access to all areas of the right-of-way. It should be noted that the operators of those vehicles would need to be specially trained on the railroad operating rules and the proper operation of on-track equipment. The remainder of the fleet vehicles should be strictly highway vehicles to serve miscellaneous transportation needs as necessary.

Amongst the objectives in the design of hi-rail equipment is the inherent characteristic of the ability to readily traverse rail tracks having ever decreasing radii. As the tracks are caused to assume smaller radii, the conventional hi-rail equipment tends to cause the leading and/or trailing ends of the associated chassis to extend an unreasonable degree beyond the track bed. Such conditions expose the overhanging portions of the hi-rail equipment to unwanted collision or impact with equipment on adjacent tracks and other stationery objects, which are normally out of the zone of contact.

Accordingly, it is an objective of the present invention to produce a hi-rail equipment vehicle wherein the track engaging wheels are disposed to reduce the amount of overhang of the chassis permitting the equipment to traverse track configuration of ever-decreasing radius.

SUMMARY OF THE INVENTION

The above, as well as other objectives of the invention, have surprisingly been achieved by a hi-rail vehicle including a vehicle chassis; ground engaging wheels attached to the underside of the chassis including at least a pair of ground engageable steerable front wheels and a bogie unit of front and rear driving wheels; at least a first pair of rail engaging wheels mounted for selective vertical movement in front of the pair of ground engaging steerable front wheels; and at least a second pair of rail engageable wheels mounted for selective vertical movement interdigitated between the front and rear driving wheels of the bogie unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The above, as well as other objects and advantages of the invention, will become readily apparent to those skilled in the art from reading the following detailed description of the invention when considered in the light of the accompanying drawings, in which:

FIG. 1 is a side elevational view of a hi-rail equipment vehicle produced in accordance with the present invention; and

FIG. 2 is a diagrammatic top plan view illustrating the disposition of the rail engaging wheels in respect of the hi-rail equipment vehicle chassis and an associated curved section of railway track.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

Referring to the drawings, there is illustrated a hi-rail equipment vehicle generally designated by reference numeral 10 having a chassis 12. The chassis 12 is fitted with couplers 14 and 16 on the front end and the rear end of the chassis 12, respectively.

The vehicle 10 includes an operators cab 18 and an associated drive engine within a normally closed hood 20. The chassis 12 is provided with suitable structural details for supporting any desired equipment having a centrally disposed crane 22. However, it will be understood the crane assembly can be substituted by many other types of railway maintenance equipment, for example.

The vehicle chassis 12 is provided with sets of rail track engaging and guiding wheels and highway engaging wheels positioned in spaced relation along the length thereof. More particularly, the chassis 12 of the vehicle 10 is adapted to travel along a highway on a pair of steerable front wheels 24. The wheel assembly and associated steering mechanism are conventional and are typically mounted to the chassis 12 by means of a conventional spring suspension mechanism. In the highway mode, the vehicle 10 is further provided with a bogie or tandem unit 26 consisting of spaced apart forward and rear sets of drive wheels 28 and 30, respectively. The bogie 26 is mounted to the chassis 12 by a suspension assembly. The sets of drive wheels 28 and 30 are connected to a drive shaft through a standard differential drive gear assembly, not shown. The other end of the drive shaft typically extends to a conventional transmission used to transmit power from the drive engine to the sets of drive wheels 28 and 30.

In the rail mode, there is provided railway track front engageable wheels 32 mounted, for selective vertical movement to the chassis 12. It will be noted that the wheels 32 are mounted in front of the front steering wheels 24 and are mounted to the chassis 12 through independent torsion spring suspension mechanism. The torsion spring mechanism is adapted to be selectively moved vertically. Normally, the wheels 32 are carried in an elevated position, as illustrated in FIG. 1. When it is desired to guide the front of the chassis 12 along a railway track, the torsion spring mechanism is energized to force the wheels 32 downwardly into engagement with the railway track 46. Sufficient downward force is applied to move the wheels 32 downwardly into engagement with the railway tracks, and simultaneously cause the steering wheels 24 to be urged upwardly. The procedure continues until the wheels 24 are out of contact with the supporting surface. At this point in the operation, the railway track engaging wheels 32 carry the load previously carried by the steering wheels 24, and are thereby in position to guide the front of the vehicle 10 along the railway tracks 46.

Interdigitated between the rear drive wheels 28 and 30 is disposed a rear railway engageable wheel set 34 mounted to the chassis 12 for selective vertical movement. The wheel set 34 typically includes an associated axle 36 which is mounted to extend between a forwardly extending set of spaced apart arms 38. The rearward ends of the arms 38 are affixed to a shaft 40 which, in turn, is pivotally disposed within a hollow mounting member 42 secured to the vehicle chassis 12.

The loading of the front railway engaging wheels 32 is typically carried by suspension means such as torsion springs for example. The suspension springs are employed control the vertical movement of the wheels 32 to effect a suitable loading of the rail engaging wheels 32 to effect a suitable loading of the rail engaging wheels and a simultaneous unloading of the steerable wheels 24 carrying a pneumatic tires for highway use, as explained in some detail above.

The loading of the rear railway engageable wheel set 34 is typically carried out by a hydraulic system 44 which effectively connects the railway engageable wheels 34 and the associated axle 36 to the chassis 12.

The rear railway engageable wheels 34 are positioned between the drive wheels 28 and 30 of the rear tandem to facilitate the travel of the associated vehicle 10 on very tight curves of the railway track 46, as illustrated in FIG. 2.

It will be understood that during railway track travel, the railway engaging wheels 34 are caused to be lowered from the normal position, as illustrated in FIG. 1, to a position contacting the railway track 46. Sufficient unloading of the drive wheels 28 and 30 is accomplished to permit enough tractive effort to occur between the drive wheels 28 and 30 and the railway tracks 46, and simultaneously allow the railway engaging wheels 34 to guide the rear of vehicle 10. The hydraulic system 44 is deemed to be particularly beneficial to the overall operation of the hi-rail vehicle 10 due to the inherent ability to apply a constant force between the wheels 34 and the supporting railway track 46 no matter the irregularities the drive wheel 28 and 30 may encounter. Amongst the types of irregularities which may be encountered are “frogs” in the region of track switching mechanism. Such irregularities could cause the railway engaging wheels 28 and 30 to encounter a raised surface of some two inches above normal track height. In such instances, the hydraulic system 44 will instantly compensate, by rapidly causing the wheels 34 to maintain constant contact with the railway 46.

Thereby, the vehicle 10 is able to work in transit rail yards. Where the railway tracks are oftentimes formed on very short radii. Currently, hi-rail equipment is provided with front rail engaging wheels located behind the front road wheels in an attempt to reduce the on-rail wheel base. However, such arrangement results in a structure wherein the front overhang of the chassis is excessive and can interfere with adjoining track vehicles and other obstructions. The arrangement of the present invention effectively reduces on-track vehicle overhang.

In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be understood that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.

Claims

1. A hi-rail vehicle including: a vehicle chassis; and ground engaging wheels attached to the underside of the chassis including at least a pair of ground engageable steerable front wheels and a bogie unit of front and rear driving wheels; at least a first paid of rail engaging wheels mounted for selective vertical movement in front of the pair of ground engaging steerable front wheels; and at least a second pair of rail engageable wheels mounted for selective vertical movement interdigitated between the front and rear driving wheels of the bogie unit.

2. A hi-rail vehicle for normal travel along a highway and selective travel along railway tracks comprising: a vehicle chassis; a pair of highway engageable front steering wheels connected to said chassis; at least a first pair of railway track engageable wheels mounted to said chassis in front of said pair of highway engageable steering front wheels; means for selectively imparting vertical movement to said first paid of railway track engageable wheels to cause selective highway engagement of said pair of steering front wheels; a tandem unit of spaced apart forward and rear highway engageable wheel sets connected to said chassis; at least a second pair of railway track engageable wheels mounted for vertical movement between the forward and rear highway engageable wheel sets of said tandem unit; and means for selectively imparting vertical movement to said second pair of rail engageable wheels to at least partially unload the wheel sets of said tandem unit to provide motive traction between the vehicle and associated railway tracks and simultaneously cause said second pair of railway track engageable wheels to assist in guiding the vehicle along the associated railway tracks.

3. A hi-rail vehicle as defined in claim 2 wherein said vehicle chassis includes a front end and spaced apart rear end.

4. A hi-rail vehicle as defined in claim 3 wherein said pair of ground engageable front steering wheels are connected to the front end of said vehicle chassis.

5. A hi-rail vehicle as defined in claim 4 wherein said tandem unit is connected to the rear end of said vehicle chassis.

6. A hi-rail vehicle as defined in claim 5 wherein said pair of ground engageable front steering wheels and said tandem unit are mounted to said chassis in spaced apart relation to one another.

7. A hi-rail vehicle as defined in claim 2 wherein said means for selectively imparting vertical movement to said second pair of railway track engageable wheels includes an axle for supporting the railway track engageable wheels.

8. A hi-rail vehicle as defined in claim 7 wherein said means for selectively imparting vertical movement to said second pair of rail engageable wheels further includes a pair of arms, each of said arms having a maximal end and a spaced apart distal end.

9. A hi-rail vehicle as defined in claim 8 wherein the proximal ends of said pair of arms are pivotally connected to said chassis.

10. A hi-rail vehicle as defined in claim 9 wherein the distal ends of said pair of arms are connected to the axle of said means for imparting vertical movement to said second pair of railway track engageable wheels.

11. A hi-rail vehicle as defined in claim 9 including a shaft pivotally mounted to said chassis wherein the proximal ends of said pair of arms are connected to said shaft.

12. A hi-rail vehicle as defined in claim 11 wherein said shaft is pivotally supported by a hollow mounting member connected to said chassis.

13. A hi-rail vehicle as defined in claim 2 wherein said means for imparting vertical movement to said second pair of railway track engageable wheels includes an air bag suspension spring.

14. A hi-rail vehicle as defined in claim 2 wherein said means for selectively imparting vertical movement to said first paid of railway track engageable wheels includes an air bag suspension spring.