US 20010050026 A1
This invention provides an integrated road tire-rail wheel assembly for road-rail adaptive vehicles as found in freight and mass transit systems, as well as other dual (civilian-military) use and other transport systems. The assembly includes two integrated road-rail wheels in a spaced apart relationship with each other and connected by an axle. Each integrated road-rail wheel has a road tire, a road wheel and a rail wheel. The road tire is mounted on the road wheel and the rail wheel has a disk portion and a tread portion. The road tire further includes a tread, an inner sidewall, an outer sidewall and an alignment flange. The inner sidewall is fully abutted against the disk portion of the rail wheel. The alignment flange of the road tire extends outwardly and beyond the rail tread portion of the rail wheel. In addition the assembly further includes a means for automatic inflation and deflation of the road tires that is enabled only while the vehicle is operating on rails. The invented wheel system is called the “Marchetti” wheel, in memory of Luigi Marchetti (˜1865-1950), an Italian immigrant, and a fireman on the Erie-Lackawanna Railway.
1. An integrated road tire-rail wheel assembly, said assembly comprising:
a pair of integrated road-rail wheels, each integrated wheel having a road tire, a road wheel, and a rail wheel, said road-rail wheels having a spaced apart relationship with each other, and
an axle connected between said integrated road-rail wheels.
2. An integrated road tire-rail wheel assembly according to
3. An integrated road tire-rail wheel assembly according to
4. An integrated road tire-rail wheel assembly according to
 This application is a continuation in part application of, and claims priority from, U.S. patent application Ser. No. 09/859,144, filed on May 15, 2001, entitled “Road-Rail Adaptive Vehicle Transit System”, which claims priority from patent application Ser. No. 60/220,401, filed on Jul. 24, 2000, entitled “Road-Rail Adaptive Vehicle Mass Transit System,” the disclosures of which are incorporated herein by this reference.
 1. Field of the Invention
 This invention relates generally to freight transport and mass transport of humans. More specifically this invention relates to integrated assemblies of road tires and rail wheels for road-rail adaptive vehicles as found in freight and mass transit systems, as well as other dual (civilian-military) use and other transport systems.
 2. Related Art
 For many years specially constructed devices have been designed, patented and used to adapt road vehicles for use on railroad tracks. It is not uncommon to see a standard pickup truck making its way along a railroad track under its own power. Generally such adaptations are made to support railroad service and maintenance operations. Typically the road vehicle is driven in a conventional fashion to the selected point at which it is to begin using the railroad track. After positioning the road vehicle over the rails, the rail engagement apparatus is actuated such that the rail wheels are lowered from the vehicle to the track. This process may simultaneously raise the vehicle's front road wheels to eliminate their contact of the road wheels with both the rails and the track bed. Alternatively the front road wheels are raised in a separate mechanical operation. The rear road wheels usually remain in contact with the rails or the track bed to provide the needed propulsion. When the road vehicle is to be returned to normal road usage, the above described process is reversed.
 As in the above description, all of the known designs incorporate separate road wheel and rail wheel pairs which may be raised or lowered depending on the desired transport mode, i.e. road or rail. Some of these designs incorporate the mechanism for raising and lowering the road/rail wheels in the basic design of the vehicle. Others provide a separate wheel assembly or “bogie” which mates with the chassis of the vehicle to adapt it to the alternate transport mode. A few of the known and relevant examples representative of the above approaches are presented in the following:
 Madison (U.S. Pat. No. 5,186,109) teaches an adaptation device having railroad wheels that attaches to a frame of a road vehicle. This device has a side shift capability whereby the railroad wheels may be lowered to engage the rails when the road vehicle is offset sideways and parallel to the tracks. An automatic system centers the vehicle over the tracks after the rail wheels have engaged the rails. A spring arrangement is also provided to maintain the rail wheels in contact with the rails.
 In two subsequent patents, (U.S. Pat. No. 5,619,931) and (U.S. Pat. No. 5,868,078), Madison provides truck tractor vehicle frames for adaptation for rail use. These frames also enable the tractor to be used on a roadway. Each patent incorporates a front guide rail wheel unit and a rear road wheel drive unit. When the front unit is lowered the rail wheels engage the track's rails. When the front unit is raised, separately mounted road wheels engage the roadway. When the rear unit is lowered its road wheels are in contact with the roadway. Raising the rear unit allows a separately mounted rear rail wheel bogey to engage the rails.
 Bush (U.S. Pat. No. 5,740,742) has adapted a truck tractor for use on railways to tow one or more railcars while retaining the capability to tow highway trailers. Bush provides a set of hydraulically retractable railway wheels to guide the rear drive wheels while on the rails. The front of the tractor is equipped with a set of retractable railway wheels that are used to lift the front steering axle of the truck tractor clear of the railroad rails.
 Kershaw (U.S. Pat. No. 6,021,719) has invented a self-propelled track vehicle capable of traveling at highway speeds and traveling by rail. This is accomplished by providing separate sets of road and rail wheels all of which may be selectively raised and lowered to enable the desired operating mode. Kershaw also provides a turntable device attached to the vehicle's chassis so that it may be rotated 90 degrees for placement on the railway track.
 Pyle (U.S. Pat. No. 6,199,485) provides a rail conversion module for a tractor that allows the tractor to be driven either on the ground or on railroad tracks. He provides a hinged frame module that fits under the tractor with front rail wheels and driven rear rail wheels. Both wheel sets may be raised for ground travel or lowered for travel by rail.
 As can be readily concluded from the above discussion, this wide assortment of conversion and adaptation devices are complicated by their need to incorporate raising and lowering mechanisms or to provide a separate undercarriage to allow for the second transportation mode. This complexity adds fabrication cost, increases vehicle weight and maintenance, reduces reliability and may adversely impact operational safety. Such systems are also complex to operate, particularly when making roadway-railway transitions.
 With the advent of freight and mass transit systems incorporating road-rail adaptive vehicles as disclosed in this inventor's preceding patent application (id.), a critical need exists for new methods for reliably and efficiently transitioning from a roadway or railway transportation mode to the other mode. To provide a seamless transition, the vehicle must be liberated from the complex equipment and processes taught in the prior art.
 Thus it is a primary object of this invention to provide wheel assemblies for road-rail vehicles that will efficiently, effectively and safely function on either a roadway or a railway. It is a further object of this invention that this assembly may not require any actuation mechanisms to accomplish the roadway/railway transition. It is yet a further object of this invention that the roadway/railway transition may be accomplished automatically without operator intervention. It is a final object of this invention to provide a wheel assembly that is lightweight yet structurally sound for the intended dual use, roadway/railway application.
 This invention provides an integrated road tire-rail wheel assembly for road-rail adaptive vehicles as found in freight and mass transit systems, as well as other dual (civilian military) use and other transport systems. The assembly includes two integrated road-rail wheels in a spaced apart relationship with each other and connected by an axle. Each integrated road-rail wheel has a road tire, a road wheel and a rail wheel. The road tire is mounted on the road wheel, and the rail wheel, which is adjacent to the road wheel, has a disk portion and a tread portion. Preferably, the road wheel is distal, and the rail wheel is proximal, from the center of the vehicle. The road tire further includes a tread, an inner sidewall, an outer sidewall and an alignment flange. The inner sidewall is fully abutted against the disk portion of the rail wheel. The alignment flange of the road tire extends outwardly and beyond the rail tread portion of the rail wheel. In other words, the road tire has a larger diameter than the rail wheel. The flange section of the tire serves as the rail alignment flanging device such as incorporated in the design of a conventional railroad wheel. The axles are provided with conventional differentials and universal joints to accommodate turning and translation movements.
 In addition the assembly may further include a means for automatic inflation and deflation of the road tires that is enabled only while the vehicle is operating on rails. This means senses the presence, for example, of a crossroad, and rapidly deflates the road tire so that the vehicle remains fully supported by the rail wheels acting on the rails. In a like fashion, when the absence of the cross-road is sensed, the road tire is quickly re-inflated to again provide the rail flanging function of the road tire.
 These and many other features and attendant advantages of the invention will become apparent as the invention becomes better understood by reference to the following detailed descriptions and accompanying drawings. We refer to this invention of the “Marchetti” wheel, in memory of Luigi Marchetti (˜1865-1950), an Italian immigrant, and a fireman on the Erie-Lackawanna Railway.
FIG. 1 shows the integrated “Marchetti” road tire-rail wheel assembly of this invention in operation on a conventional roadway.
FIG. 2 shows the assembly operating on railway tracks, the right portion of this figure providing additional clarity with a sectional view of a road-rail wheel.
FIG. 3 shows the operation of the means for automatic inflation and deflation of this invention.
FIG. 4 shows the undercarriage of a typical vehicle incorporating the use of road tire-rail wheel assemblies according to this invention.
 Referring to FIGS. 1 and 2, this invention is for an integrated road tire-rail wheel assembly 1 for use with road-rail adaptive vehicles. Such vehicles are used with freight and mass transit systems. The invention is applicable “as well in other dual (civilian-military) use systems for transporting troops, ordinance, and/or material to unknown, unpredictable destinations, via road and rail, to simplify logistics, improve costs, schedules, time-to-destination, and other efficiencies. The concept also include exclusive custom/luxury transit vehicles, as well as mass market SUV and others vehicles. In the preferred embodiment of this invention, assembly 1 comprises a pair of integrated road-rail wheels 5, each integrated wheel having road tire 10, road wheel 20, and rail wheel 30. In addition, the road tire has tread 12, inner sidewall 14, outer sidewall 16 and alignment flange 18. The rail wheel has disk portion 32 and rail tread portion 34. The disk portion of the rail wheel may be reinforced with radial stiffener sections (not shown). The two road-rail wheels have a spaced apart relationship with respect to each other and are operatively inter-connected by axle 40. The axle is fitted with a known differential and steering knuckles. The assembly may also be fitted with known tie rods, king pins and the like.
 Continuing reference to FIGS. 1 and 2, road tire 10 is conventionally mounted on road wheel 20. Alignment flange 18 serves as the rail alignment flanging device such as incorporated in the design of a conventional railroad wheel. As such, the alignment flange assures the full stability and integrity of the vehicle while it operates in the railway mode, particularly during curved portions of the track. To properly accomplish this function, inner sidewall 14 must be fully abutted against the disk portion of the rail wheel. As shown in FIGS. 1, 2 and 3, it is essential that the alignment flange of the fully inflated tire extend outwardly and beyond the tread section of the rail wheel.
 The length of the axle is designed and manufactured to accommodate the particular gauge of the railway for the route being used by the vehicle. These gauges are most commonly the Standard Gauge, Narrow Gauge and Wide Gauge.
 The preferred embodiment of this invention further includes means for automatic inflation and deflation 50 of the road tires that is enabled only while the vehicle operates on rails. This means senses the presence, for example, of a crossroad, and rapidly deflates the road tire so that the vehicle remains fully supported on the rails. In a like fashion, when the absence of the cross-road is sensed, the road tire is quickly re-inflated to again provide the rail alignment flanging function of the road tire.
FIG. 1 shows this invention in operation on conventional roadway 100. In this transportation mode, fully inflated road tire 10 extends past the perimeter or rail wheel 30 thereby fully supporting the vehicle on the roadway. FIG. 2 depicts this invention operating on a standard railway rails 200. In this railway transportation mode, rail tread 34 rides on the top of rail 200 thereby raising the road tire above the surface of the railway bed. It is important to note that for this standard railway mode, the road tire may remain inflated.
 The operation of the means for automatic inflation and deflation is illustrated in FIG. 3. The right portion of this figure shows fully inflated tire 10. In the left portion of FIG. 3, the road tire is shown after it has been automatically deflated immediately subsequent to detection of a change in the rail bed, e.g. crossroad 150. The deflation of the tire is indicated by the bulging profile of outer sidewall 16 a. It is important to note that under both the fully inflated and deflated conditions, alignment flange 18 remains in full contact with rail 200 thus assuring the proper and effective alignment of the vehicle on the rails.
 Materials used in the manufacture of this invention are conventional other than alignment flange 18 which must be formed from a rigid composition of hard/composite material bonded to the road tire casing.
FIG. 4 is a conceptual drawing of a typical vehicle application of the road tire-rail wheel assembly according to this invention. In this figure, two pairs of assembly 1 are shown affixed to the undercarriage of a vehicle. The assemblies are both steerable to accommodate railway track curvature. In this example, power unit 300 drives both assemblies via driveshafts 400.
 Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims.