BACKGROUND OF THE INVENTION

The present invention relates generally to bimodal hauling vehicles which can be converted for use on both railways and roadways, and to a method for using the vehicles. In particular, the present invention is a bimodal hauling vehicle and associated method of use which permit one operator to operate the vehicle on both a highway and railway, and to convert the vehicle between highway and railway operation at a grade crossing.

In many areas such as rural locations and developing countries, railways are a more effective means of transportation than roadways. Unfortunately, known convertible railway-highway vehicles are relatively complicated to operate. Railways therefore tend to be an underutilized mode of transportation for smaller organizations or individuals such as farmers that are not hauling large quantities of goods typically required for the efficient operation of these known bimodal systems.

It is therefore evident that there is a continuing need for improved convertible railway-roadway vehicles. In particular, there is a need for vehicles of this type that can be conveniently converted between railway and highway travel operating modes at grade crossings. Vehicles of this type would be especially useful if they can be converted between railway and highway operating modes by one person, and efficiently operated by one person on both the railway and highway. To be commercially viable, any such vehicle must of course be capable of being efficiently manufactured.

SUMMARY OF THE INVENTION

The present invention is a puller for use in conjunction with a conventional over-the-road tractor for hauling convertible roadway-highway trailers on a railway, and a method for using the puller in conjunction with the tractor and trailers. One person can conveniently use the tractor and puller to convert the trailers between highway and railway

operating modes at any grade crossing, and to haul the trailers on both the highway and railway. No special ramps are required, and the removable railway bogies can be stored at any convenient location.

In one embodiment the puller includes a platform for receiving and supporting a tractor, railway bogies mounted to the platform for supporting the platform for railway travel, and a drive system. The railway bogies include at least one driven axle. The drive system is coupled to the driven wheel and configured for interconnection to and powered by a tractor.

In other embodiments the puller includes a retractable ramp mounted to the platform to enable a tractor to be driven onto and off of the platform. The drive system includes an electric motor coupled to the driven wheel, and a generator configured to be driven by a tractor for powering the electric motor. An auxiliary engine can also be mounted to the platform and connected to drive the generator.

The method by which the puller is used in conjunction with a tractor and convertible roadway-railway trailers to haul the trailers includes configuring the trailer for railway travel and operating the tractor to remove the trailer from the roadway and position the trailer on the railway, driving the tractor onto the puller and connecting the tractor to the puller drive system, and operating the tractor to connect the puller to the trailer and drive the trailer over the railway when the trailer is positioned on the railway and configured for railway travel. The method also includes disconnecting the tractor from the puller drive system and driving the tractor off of the puller, configuring the trailer for roadway travel and operating the tractor to remove the trailer from the railway and position the trailer on the roadway. The trailer is connected to the tractor and driven over the roadway when the trailer is positioned on the roadway and configured for roadway travel.

In one embodiment the method is used in conjunction with a convertible roadway-railway trailer having retractable roadway wheels. Configuring the trailer for railway travel and operating the tractor to remove the trailer from the roadway and

position the trailer on the railway includes operating the tractor while the trailer is on the roadway and the railway bogies are off the railway to position the trailer over the railway bogies, retracting the roadway wheels to lower the trailer onto the railway bogies, connecting the railway bogies to the trailer, extending the roadway wheels to lift the railway bogeys, operating the tractor to position the trailer and railway bogies over the railway, and retracting the roadway wheels to lower the railway bogies and trailer onto the railway. Similarly, configuring the trailer for roadway travel and operating the tractor to remove the trailer from the railway and position the trailer on the roadway includes extending the roadway wheels to raise the railway bogies and trailer from the railway, operating the tractor to remove the trailer and railway bogies from the railway and position the trailer on the roadway, retracting the roadway wheels to lower the railway bogies, disconnecting the railway bogies from the trailer, and extending the roadway wheels to lift the trailer off of the railway bogies.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a side view of a convertible railway-roadway trailer which can be used in conjunction with the puller and method of the present invention, configured in the roadway mode of operation with the highway wheel assembly located at the posterior end.

Figure 2 is a side view of the trailer shown in Figure 1 with the highway wheel assembly positioned at the middle of the main body of the trailer.

Figure 3 is a side view of the trailer shown in Figure 1 when the lifting means of the highway wheel assembly is inflated and the railway wheel bogie is positioned underneath the posterior end of the trailer.

Figure 4 is a side view of the trailer shown in Figure 1, configured in the railway mode of operation with the highway wheel assembly retracted and the railway wheel bogie securely attached to the trailer.

Figure 5 is a bottom view of the trailer shown in Figure 1, configured in the railway mode of operation with the highway wheel assembly positioned in the middle of the trailer and the railway wheel bogie securely attached to the posterior end of the trailer.

Figure 6 is a side view of the railway wheel bogie of the trailer shown in Figure 1.

Figure 7 is an exploded side view of the trailer shown in Figure 1 with the slidable highway wheel assembly, the lifting means, the retracting means, and the undercarriage rail that the highway wheel assembly slides on positioned underneath the trailer.

Figure 8 is a side view of a puller in accordance with the present invention with the ramp extended.

Figure 9 is a top view of the puller shown in Figure 8.

Figure 10 is a side view of the puller shown in Figure 8 with a tractor on the puller and the ramp retracted.

Figure 11 is a side view of the trailer shown in Figure 1 when the railway wheel bogie is attached to the trailer and the highway wheel assembly is inflated to lift the railway bogie off the track.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A bimodal hauling trailer or vehicle 2 which can be used in conjunction with the puller and method of the present invention is illustrated generally in Figures 1-7. Complete descriptions of the puller and method can be found below in subsequent portions of this specification.

Vehicle 2 is convertible between highway (roadway) and railway use and includes a main body 4, a front or anterior end 6, a rear or posterior end 8, a bottom 7 and a highway wheel assembly 10 slidably attached to the bottom 7 at the posterior end 8. At the anterior end 6 is a first connecting means 12 and second connecting means 14. The first connecting means 12 is preferably a fifth wheel 13 attached to the bottom 7 and used for connecting the hauling vehicle 2 to a highway moving means such as a semi-truck or tractor 60 such as that illustrated in

Figure 10. The second connecting means 14 is preferably a vertical steel pin 15 on a steel hitch 11. The steel hitch 11 and pin 15 extend attachably in front of the anterior end 6 at the bottom 7 with the steel hitch 11 attached to the bottom 7. The pin 15 is made to be easily inserted into a corresponding hole 17 in a steel hitch 16. Steel hitch 16 is located on the posterior end of a puller of the type shown in Figures 8-10 and described below, or on the posterior end 8 of a hauling vehicle 2. The steel hitch 16 is slidably attached to the bottom 7 at the posterior end 8 of the hauling vehicle main body 4. The hitch 16 is slid underneath the main body 4 during highway use. During railway use, the hole 17 in the steel hitch 16 is extended past the posterior end 8 for connecting to the pin 15 of a second hauling vehicle 2. This allows a train of hauling vehicles to be connected together, one after the other. The hauling vehicle 2 also has a retractable pair of dolly wheels 5 located on the bottom 7 at the anterior end 6 of the main body 4. These wheels are used for supporting the hauling vehicle 2 when not in use. The dolly wheels 5 are held in place with a pin and hole combination 3.

As shown in Figure 7, the slidably attached highway wheel assembly 10 has at least one axle, preferably two, a locking means 42, a lifting means 18 and a retracting means 20. The locking means 42 is a pair of pin and hole combinations located on each side of the hauling vehicle 2. The holes are in both the slidably attached highway wheel assembly 10 and an undercarriage rail 38. The undercarriage rail 38 is permanently attached to the bottom 7 of the hauling vehicle 2 and runs from the posterior end 8 longitudinally toward the anterior end 6 of the main body 4, ending in the middle of main body 4. To lock and unlock the slidable highway-wheel assembly 10, pins are inserted or removed from the holes in the highway wheel assembly 10 anr undercarriage rail 38 when the holes are in line with each ,ιer. When the pins are removed, the highway wheel assembly 10 slides on the undercarriage rail 38, thus allowing the highway wheel assembly 10 to be repositioned beneath the main be y 4 of the hauling vehicle 2. The extending or lifting

means 18 is preferably an air bag assembly and the retracting means 20 is preferably leaf springs. Both the extending or lifting means 18 and the retracting means 20 are attached to the highway wheel assembly 10 and slide with the highway wheel assembly 10 when it is moved back and forth.

As shown in Figure 1, the highway wheel assembly 10 is equipped with conventional air brakes which are located generally on the bottom 7 at the posterior end 8 of the hauling vehicle 2. During highway use the highway wheel assembly 10 is locked in position at the posterior end 8 with the locking means 42. To convert the hauling vehicle 2 into a railway vehicle, the locking means 42 is unlocked, a tractor 60 such as that shown in Figure 10 is engaged or connected to the hauling vehicle, the air brakes are applied, and the tractor is operated to push or slide the hauling vehicle main body 4 longitudinally in the direction of the posterior end 8. This action slides the highway wheel assembly 10 forward underneath the main body 4. As shown in Figure 2, the result of sliding the main body 4 in the direction of the posterior end 8 is the highway wheel assembly 10 being located in the middle of the main body 4. The highway wheel assembly 10 is then locked in place with the locking means 42.

With the highway wheel assembly 10 locked in position in the middle of the main body 4, the air bag assembly 18 is inflated to lift the posterior end 8 of the hauling vehicle 2 to a height greater than that of the railway wheel bogies 24 to which the vehicle is to be mounted. As shown in Figures 3 and 5, a socket 26 is located underneath the main body 4 at the posterior end 8. The tractor 60 is then operated to position the hauling vehicle 2 in such a manner that the main shaft 22 of the railway wheel bogie 24 is located below the socket 26. The air bag assembly 18 is deflated to retract wheel assembly 10 and lower vehicle 2 until the main body 4 comes to rest on the railway bogie 24. This lowers the socket 26 of the posterior end 8 over the main shaft 22 of the railway wheel assembly 24, removably inserting the shaft 22 into the socket 26.

As shown in Figures 4, 5 and 6, the railway wheel bogie 24 includes a conventional electro-mechanical braking system, a main shaft 22, a frame 34, wheels 50, sway reducing bars 32 and permanently attached pins 29. The main shaft 22 removably fits into the socket 26 located at the posterior end 8 of the hauling vehicle 2. The railway wheel bogie 24 is securely attached to the main body 4 using the pins 29 permanently attached to the railway bogie 24, pins 28 permanently attached to the main body 4 and chains 30. Two pins 28 are permanently attached to each side of the main body 4 and one pin 29 is permanently attached to each side of the railway wheel bogie 24. A chain 30 is secured on each side of the hauling vehicle 2 to the pins 28 and 29, one chain 30 for each side. This arrangement securely but removably fastens the railway wheel bogie 24 to the hauling vehicle 2. Inflating the air bags 18 allows the hauling vehicle 2, with railway wheel bogie 24 attached, to be relocated to a desired track through use of tractor 60. The sway reducing bars 32 on the railway wheel bogie 24 hit against the sway reducing pads 36 permanently attached to the bottom 7 of the hauling vehicle 2. This reduces the sway of the hauling vehicle 2 when used for railway travel. Two sway reducing bars 32 and one sway reducing pad 36 are located on each side of the hauling vehicle 2. The sway reducing pads 36 are located on the outside of the undercarriage rail 38. The electro-mechanical brakes of the railway wheel bogies are connected to a wiring harness 40 that runs the length of the hauling vehicle 2, connecting one hauling vehicle 2 to another and to puller 62. Although tandem axle railway wheel bogies 24 are shown in Figures 3-6, single axle railway wheel bogies (not shown) can be used as well.

The above-described procedure for mounting railway wheel bogie 24 to hauling vehicle 2 when configuring the vehicle for railway operation can be performed with the railway bogie located on the railway over which the vehicle is to travel. Al ernatively, this procedure can be performed while the railway wheel bogie 24 is positioned at a storage location, such as a ditch or other convenient location, away from the railway. After the hauling vehicle 2 is mounted to a railway bogie 24

while the railway bogie is at a storage location, airbag assembly 18 is inflated to extend highway wheel assembly 10 and raise the railway wheel bogie off of the ground or railway on which it is stored. Figure 11 illustrates a hauling vehicle 2 with railway wheel bogie 24 attached and highway wheel assembly 10 extended to lift the bogie off the ground. Tractor 60 is then operated to move the hauling vehicle 2 to the railway, and, at a grade crossing, to position the hauling vehicle and railway wheel bogie over the railway. Airbag assembly 18 is then deflated to retract the highway wheel assembly 10 and lower the hauling vehicle 2 and railway wheel bogie 24 onto the railway. Tractor 60 can then be disconnected from the hauling vehicle 2 and driven away.

The procedure for mounting railway wheel bogie 24 to vehicle 2 can also be performed in two steps. With the highway wheel assembly 10 in its extended position the posterior end 8 of hauling vehicle 2 can be positioned by means of tractor 60 generally over railway wheel bogie 24. In particular, hauling vehicle 2 need not be positioned to such a high degree of accuracy that socket 26 is located directly over main shaft 22 of railway wheel bogie 24. Highway wheel assembly 10 is then retracted somewhat to lower posterior end 8 of hauling vehicle 2 adjacent to railway wheel bogie 24, and chains 30 attached to pins 28 and 29. Railway wheel bogie 24 is thereby secured to hauling vehicle 2 for transportation to the railway. Shaft 22 of railway wheel bogie 24 need not be positioned within socket 26 for typically short distance transportation. After railway wheel bogies 24 are properly positioned on the railway, chains 30 can be removed and the position of hauling vehicle 2 adjusted with respect to the railway wheel bogies to position shaft 22 in socket 26. The chains 30 are then reattached to securely mount the railway wheel bogie 24 to hauling vehicle 2. An advantage of this two-step procedure is that it alleviates the need for the operator to precisely align socket 26 over shaft 22, which might otherwise be more difficult when the railway wheel bogies are stored at a sloping or other off-track location.

As shown in Figure 4, when the railway wheel bogie 24 has been positioned on the desired track, the airbag assembly 18 is fully deflated and the highway wheel assembly 10 retracted to a position above the bottom of the railway wheels 50. In the embodiment shown in Figure 7, the retracting means 20 is a set of leaf springs attached to the highway wheel assembly 10. The leaf springs 20 pull the highway wheel assembly 10 up to the main body 4 and out of the way for railway travel.

To convert the hauling vehicle 2 from railway travel to highway travel, the airbag assembly 18 is inflated to extend the highway wheel assembly 10 and raise the railway wheel bogie 24 off the railway. The tractor 60 is then operated to remove the hauling vehicle 2 from the railway at a grade crossing, and to move the vehicle to a track or other storage location at which the railway wheel bogie 24 is to be stored. The railway wheel bogie 24 can, for example, be conveniently stored in a ditch adjacent the grade crossing at which the hauling vehicle 2 is removed from the railway. The railway wheel bogie 24 is positioned over the storage track and the airbag assembly 18 deflated to retract wheel assembly 10 and lower the railway wheel bogie onto the track. Chains 30 connecting the main body 4 and railway wheel bogie 24 are then removed from the pins 28 and 29. The airbag assembly 18 is then inflated to extend highway wheel assembly 10 and raise the posterior end 8 of the hauling vehicle 2 above the railway wheel bogie 24, so the main shaft 22 slides out of the socket 26. The hauling vehicle 2 is moved away from the railway wheel bogie 24 through operation of the tractor 60, and the airbag assembly 18 deflated to position the hauling vehicle at a level appropriate for highway travel.

After hauling vehicle 2 is removed from railway wheel bogies 24, the locking means 42 holding the highway wheel assembly 10 is unlocked and the air brakes of the highway wheel assembly set. Tractor 60 - ^" s then operated to pull the main body 4 forward. This action es the highway wheel assembly 10 to the posterior end 8. The highway wheel assembly 10 is then locked into place with the locking means 42, and the air brakes released. With hauling vehicle 2 configured for highway travel

in this manner, tractor 60 can be used to pull the hauling vehicle over the roadway.

A puller 62 which can be used in conjunction with tractor 60 to pull convertible railway-highway vehicles such as hauling vehicle 2 over the railway is illustrated generally in Figures 8-10. As shown, puller 62 includes a platform 64 supported for over-the-railway travel by railway bogies 66. A drive system 68 is mounted on the rear of platform 64 in the embodiment shown and includes a dynamo or generator 70 coupled to drive motor 72. Generator 70 includes a drive shaft 74 configured to be mounted to the power take off (PTO) of tractor 60. Motor 72 is coupled to a driven wheel such as 76 of the bogie 66 on the rear of puller 62. An auxiliary diesel or other engine 78 can also be mounted to platform 64 and used to drive generator 70. Although not shown, other embodiments of puller 62 can include an enclosure with sides and a windshield for surrounding the tractor 60 after the tractor has been driven onto the platform 64.

Puller 62 can also include ramps 80 for loading and unloading tractor 60 over the front of platform 64. Ramps 80 can be pivotally or slidably mounted to platform 64 for ease of extension and retraction. In other embodiments (not shown) , the ramp is a structure fixed to the ground at the end of a railway siding, rather than part of the puller.

Puller 62 is used by an operator to pull one or more vehicles such as 2 over the railway after the vehicles have been configured for railway travel and positioned on the railway in the manner described above. With ramps 80 extended, an operator will back tractor 60 up the ramps and onto platform 64 as shown in Figure 10. The operator will then connect the drive shaft 74 to the power take off of tractor 60, and retract ramps 80. With the parking brake (not separately shown) of tractor 60 set, the operator can use the power from tractor 60 to drive generator 70 and thereby control the movement of puller 62. When operated in this manner puller 62 can be connected to a hauling vehicle 2 by means of hitch 16, and used to interconnect additional hauling vehicles to the vehicle attached to the puller. Once all the

hauling vehicles 2 are connected to puller 62, and all the air brakes of the hauling vehicles are interconnected to one another and to tractor 60, the puller can be operated to pull the vehicles to their desired location. Alternatively, puller 62 can be powered by engine 78.

After vehicles 2 have been driven to their destination and disconnected from puller 62, ramps 80 are extended and drive shaft 74 disconnected from the power take off of tractor 60. Tractor 60 can them be driven off of puller 62 and operated in the manner described above to remove the hauling vehicles 2 from the railway, configure the hauling vehicles for roadway travel, and pull the vehicles over the roadway.

The present invention offers considerable advantages over prior art bimodal systems. Both the hauling vehicles and the puller are relatively uncomplicated vehicles that can be efficiently manufactured and conveniently operated. These vehicles also enable on operator using a conventional tractor to haul the vehicles over both railways and roadways, and to conveniently configure the hauling vehicles for both railway and roadway operation. Most importantly, these operations can all be performed by one person. Having the capability to independently transport the hauling vehicles between two locations by means of both railway and roadway is of considerable value in many circumstances, especially in rural areas where roadway systems are poor. Since the puller is powered by the tractor, there is no need for dedicated pullers requiring more complicated and therefore expensive drive systems. The relatively light weight puller (with respect to the weight of conventional locomotives) and the braking system alleviates compression forces on the hauling vehicles during railway travel.

Although the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention.