Cross-Reference to Related Applications

This application is a continuation-in-part of U.S. Serial No. 07/362,752, filed June 7, 1989, now pending.

Field of the Invention

The present invention relates to railroad trains formed of intermodal over-the-highway trailers coupled together. More particularly, this invention relates to a novel, low-cost ramp system for raising and lowering intermodal highway trailers to facilitate assembly with or disassembly from railtrucks for intermodal transportation. The system may be portable and is not limited to highway trailers having a particular wheel suspension system.

Description of the Prior Art

A variety of types of intermodal transportation have been developed which enable a train of highway trailers to travel along a railroad track. Such systems attempt to utilize the flexibility and efficiency of

highway trailers or semi-trailers for short hauling of units and yet achieve the fuel, labor and equipment cost advantages of railroads for long hauls.

For many decades, the railroad industry has attempted to create an intermodal alternative to the truck which could harness these economies by piggy-backing one mode on top of the other. For example, U.S. Patent No. 4,190,393, issued to Landow on February 26, 1980, teaches apparatus and a method for efficiently loading and unloading highway trailers onto flatcars for rail transportation. The typical system of placing highway trailers on railroad flatcars, however, has cost penalties much greater than the economies of truck transportation alone. These disadvantages have led to the development of alternative intermodal systems.

One intermodal system which was developed to attempt to combine the capabilities of rail and highway transportation in one vehicle is set forth in U.S. Patent No. 4,202,277 to Browne et al. This system includes a highway trailer that may be operated over the highway as a truck trailer and over the railroad in unit trains. The trailer body has both highway and rail running gear, both supported by an air suspension system, and is independently supported upon the highway running gear for highway operation, and upon the railroad railtruck bogies for railroad operation. The air spring suspension allows the independent raising and lowering of the highway running gear and the railroad bogie for selective use in the railroad mode or the highway mode. The semi-trailers are couplable end-to-end to form a train of multiple semi-trailers in the railroad mode of travel.

Another approach to intermodal systems is set forth in U.S. Patent No. 4,669,391 to Wicks et al., which is incorporated herein by reference. This system includes a highway trailer which is mounted on a conventional railtruck with an intermodal adapter. In order to couple the trailer to the railtruck, the trailer is backed up to the railtruck bogie and the air suspension is inflated to lift the trailer body a few inches. Further backing of the trailer allows mounting onto the bogie. Once mounted, lock pins secure the trailer body and coupling saddle into a unitized rail platform. The air suspension air bags are then deflated and coil springs lift the highway trailer tires to clear the rail.

While both of the above systems are commercially successful systems, both require the utilization of air spring suspension systems. The commercial embodiment of the Browne et al. system utilizes the air spring suspension system to raise and lower the highway running gear and the railroad bogie. The commercial embodiment of the Wicks et al. system utilizes the air spring suspension system, or an alternate hydraulic system, to raise the trailer the appropriate distance to allow mounting onto the bogie.

As a result of the high cost and limited availability of intermodal highway trailers with air spring suspension systems, there is a need for a trailer- bogie mounting system which is able to accommodate both air spring and standard spring suspension intermodal trailers and yet utilize the available commercial railtruck units. Such a mounting system would allow utilization of intermodal systems without the need for a costly air spring suspension system.

Other prior art systems, such as the one shown in U.S. Patent No. 2,963,986 to Dobson, which have attempted to depress the track in order to raise the level of the trailer with respect to the rail bogie, fail to provide the necessary portability for versatility and to allow other uses of the railtruck when not used to assemble intermodal systems. These prior art systems are also not usable with certain commercially-available intermodal system trailers and railtrucks. U.S. Patent No. 1,785,168 issued to Young on

December 16, 1930 teaches apparatus for moving a separable cargo body from a highway truck onto a stationary platform. This is accomplished by putting ramps under the wheels of the truck to raise the body above and then lower the body onto a stationary platform. When the ramps are removed the truck may be driven away without the body.

Accordingly, a need exists for an improved system and apparatus for connection of intermodal highway trailers to, and disconnection of intermodal highway trailers from, railtrucks for intermodal transportation.

Objects Of The Invention

It is therefore a general object of this invention to provide a system for assembling and disassembling intermodal highway trailers and railtrucks for intermodal transportation which meets the aforenoted needs.

It is another general object to provide a low- cost system for assembling and disassembling intermodal trains which has a far greater universality of applica¬ tion, both as to equipment and location, than other systems heretofore available.

It is a specific object of this invention to provide a system for connection of intermodal highway trailers to railtrucks for intermodal transportation which avoids the disadvantages and complexities associated with air suspension systems.

It is a further object to provide a system for connection of highway trailers to railtrucks for intermodal transportation which accommodates an intermodal highway trailer having a conventional spring suspension. It is another object to provide a system for connection of intermodal highway trailers to railtrucks for intermodal transportation which utilizes a ramp for raising and lowering the highway trailer to allow the trailer to be coupled to and uncoupled from the railtruck. It is still another object to provide a system for assembling and disassembling intermodal trailers and railtrucks which is not limited to a particular type of trailer suspension and is portable.

Other objects, advantages and features of the present invention will become apparent upon reading the following detailed description and appended claims, and upon reference to the accompanying drawings.

Summarv Of The Invention

In accordance with one embodiment of this invention, a novel ramp is provided for use in the assembly and disassembly of intermodal highway trailers and railtrucks for intermodal transportation. The ramp is utilized in conjunction with a highway trailer having a main frame or unibody or the like and at least one highway wheel assembly, which trailer is to be mounted on or dismounted from a railtruck having a pair of side frames and a bolster supported on the side frames. The preferred rail trucks are adapted to limit the rocking movement of their bolsters on their side frames.

The ramp has an ascending portion for raising the frame of a trailer backed over the ramp. When the frame is raised the respective coupling means of the trailer frame and a railtruck can be aligned in proper relationship for coupling. The ramp has a descending portion for transferring the support of the frame from the highway wheel assembly to the railtruck by lowering the level of the trailer frame slightly into an operative position on top of the railtruck adapter. The lengths of the ascending and descending portions each can be substantially greater than the height of the elevated portion, as will be apparent from the drawings. The descending portion of the ramp can include a wheel stop to locate the railtruck in an operative location beneath the trailer for coupling during lowering of the trailer frame on top of the railtruck adapter and transfer of the load thereto. Before the trailer is backed over the ramp, the trailer wheel assembly is moved forward along the underbody of the trailer and locked to

the trailer in the forward position to provide clearance for the railtruck. As the trailer travels toward and down the descending portion of the ramp, a transverse bar on the trailer can be provided to contact the railtruck so that both move in unison and in correct alignment for coupling and load transfer.

The ramp system can comprise interconnected but spaced-apart and aligned left-hand and right-hand ramps or ramp portions which support the wheel assemblies of the trailer and allow the railtruck to fit between.

Alternatively, a single full-width ramp can be provided. Guide members are provided on the ramp to direct and guide the trailer wheels onto the ramp. The ramp is constructed of flat, rigid members of sufficient width to support the tires of the trailer wheel assemblies. The ramp itself may have one or more wheel assemblies to permit mobility on the ground or along the railroad track straddled by the ramp. The ramp may also include indicator means in the form of movable flat bars or railroad wheels extending from the ramp to or beside the railroad track to indicate proper positioning of the ramp with respect to the track and to stabilize the ramp laterally.

Brief Description Of The Drawings

For a more complete understanding of this invention, reference is made to the preferred embodiments illustrated in greater detail in the accompanying drawings and described below by way of examples of the invention. In the drawings:

Figure 1 is a diagrammatic view of a railway train comprising a locomotive and a plurality of intermodal highway trailers interconnected and carried upon railtrucks. Figure 2 is a side elevation view of a trailer coupled to a railtruck by means of the ramp system of the present invention.

Figure 3 is a side elevation view of a portion of one embodiment of a trailer atop the elevated portion of the ramp apparatus of the present invention prior to coupling with the adapter portion of the railtruck.

Figure 4 is a perspective view of the trailer atop the ramp apparatus of Figure 3 before the trailer is coupled to the adapter of the railtruck bogie. Figure 5 is a rear elevation view of the trailer atop the adapter portion of the railtruck bogie.

Figure 6 is a top plan view of the ramp apparatus of Figure 3, showing the right-hand and left- hand portions of the ramp and the wheels of the railtruck in phantom against the wheel stops.

Figure 7 is a side elevation view of the ramp apparatus of Figure 6, partially broken away to show the internal construction.

Figure 8 is a sectional view taken along line 8-8 of Figure 7.

Figure 9 is a sectional view taken along line 9-9 of Figure 7.

Figure 10 is a sectional view taken along line 10-10 of Figure 7. Figure 11 is a sectional view taken along line

11-11 of Figure 10.

Figure 12 is a sectional view illustrating the indicator means of the ramp apparatus of Figure 3 above the railtrack and prior to proper alignment.

Figure 13 is a sectional view illustrating the indicator means of the ramp apparatus of Figure 3 properly aligned with respect to the railtrack.

Figure 14 is a top plan view of an alternate embodiment of the ramp apparatus of the present invention showing wheels of the railtruck. Figure 15 is a schematic view illustrating the spring and cable wheel assembly retention system of an intermodal trailer of the present invention.

Figure 16 is a perspective view of a second embodiment of the invention. Figure 17 is a plan view of the ramp of Figure

16, with portions of the surface grating removed to show details beneath.

Figure 18 is a side elevation of the ramp of Figure 16. The yard wheels are shown lowered for use in full lines and raised in phantom lines.

Figure 19 is a diagrammatic side elevation showing the use of the ramp of the present invention to back a highway trailer onto a railtruck. The trailer is shown fully backed onto the railtruck in phantom. Figure 20 is a side perspective view, enlarged with respect to Figure 19, showing the landing gear of a highway trailer traversing the compound ascending ramp of the present invention.

Figure 21 is a diagrammatic perspective view of the front axle of a railtruck as received by the descending part of the ramp.

Figure 22 is a plan view of one of the railroad wheel assemblies of Figure 16, shown in isolation.

Figure 23 is a front elevation of the assembly of Figure 22, with parts of the ramp frame shown in phantom.

Figure 24 is a section taken along line 24—24 of Figure 23.

Figure 25 is a fragmentary inside perspective view of one of the railroad wheel assemblies, showing the wheel chock linkage.

Figure 26 is a top perspective view of the structure of Figure 25.

Figure 27 is an outside perspective view of the structure of Figure 25. Figure 28 is a fragmentary side elevation of one rail wheel shown in Figure 25, showing the position of the wheel chocks in relation to the wheel and rail. The wheel chocks are shown released in phantom and engaged in solid lines. Figure 29 is an isolated plan view of one yard wheel suspension.

Figure 30 is a front elevation of the structure shown in Figure 29.

Figure 31 is a side elevation of the structure of Figure 29. The wheel frame is shown raised in solid lines and lowered in phantom.

Figure 32 is a view, partly in section, taken along line 32—32 of Figure 30.

Detailed Description Of The Preferred Embodiments

Turning now to the drawings, Figure 1 illustrates a railway train comprising a plurality of intermodal system highway trailers interconnected together and coupled to railtruck bogies. The highway trailers are indicated generally at 10 and are pulled by a locomotive 12. When the trailers are interconnected, the trailer wheel assemblies 14 are supported above the track or rail 16. The trailers are designed for use in a unit train where all of the trailers have a similar chassis and coupling structure.

The trailers in the train are modified highway trailers, which are carried by adapters on standard type railtrucks equipped with standard railway type air brakes. At the front end of the trailer is a tongue 18 which is secured to the trailer in a load carrying relationship. When a trailer is carried over the highway or around the rail yard, the front end is carried by the fifth wheel of a truck tractor or rail yard hostler. At the back end of the trailer, the wheel assemblies 14 may be mounted on a subframe 20. The wheel assemblies are kept in sliding engagement along the subframe 20 to allow movement between multiple positions. The wheel assemblies are typically in the rearward position for highway travel and in the forward position for rail travel. The wheel assemblies may be supported by a standard leaf spring suspension. As a result of the ramp system described below, an air suspension system is not necessary to raise the trailer with respect to the highway wheels in order to mount the trailer on the bogie.

In Figure 2, the trailer is shown coupled to the railtruck bogie. The railtruck 30 includes wheels 32 and a side frame 34. The railtruck is shown in more detail in Figures 4 and 5. The truck includes a bolster 36 which extends between the side frames. The bolster 36 is of generally box-shaped construction at each end. Compression members or coil springs 38, 39, contained within a spring nest, help support the bolster.

The adapter 40 for the intermodal system is located on the top of bolster. A pair of flat parallel plates 41, 42 extend along the adapter. At the ends of the plates are a pair of spaced apart top portions 44, 45. The top portions 44, 45 form the coupling portion of the railtruck. The top portions are typically box-like and formed of a series of flat plates, such as the top plates 46, 47. The top portions rest on a plurality of compressible members, including bearings 48, 49.

The trailer 10 includes a body 50 of conventional over-the-highway semi-trailer dimensions. The body 50 has a male coupling member or tongue 18 at its front end and a female coupling member 52 at its rear end to receive the male member of an adjacent body. Each trailer includes a conventional kingpin 54 adjacent its front end for removable coupling to the fifth wheel of a tractor, far highway transportation, or hostler 55 for rail yard transportation. The trailer also includes conventionally placed telescoping landing gear 56.

The bottom of the trailer includes a coupling means 58 which is an integral and permanent part of the trailer body. The coupling member is capable of detachably coupling with the top portions of the railtruck adapter. The trailer coupling means may be a pair of

socket-like members 58a, 58b, to receive the box-like top portions 44, 45 of the railtruck adapter. A releasable locking means, such as a pin (not shown), extends through an aperture 59 in the railtruck end portions and an aperture (not shown) in the trailer coupling member 58. The bottom of the trailer also includes a rigid bar 60, commercially known as an I.C.C. bar, which extends at least partially across the width of the trailer.

The ramp system of the present invention is shown generally at 62 in Figures 2, 3 and 6, and in detail in Figures 7-13. As seen in Figure 3, the ramp 62 includes an ascending portion 64, a flat elevated portion 66 and a descending portion 68. The ascending portion 64 is preferably of the same length as the descending portion 68 which allows each of the aforesaid portions to be reversible with one another.

The elevated portion is preferably at a height above the ground which is substantially less than the length of the ascending portion. This allows clearance of the landing gear 56 over the ramp as the trailer ascends the ramp. Preferably the angle formed between the ascending portion and the horizontal is on the order of seven degrees.

The ramp is formed of a right-hand portion 70 and a symmetrical left-hand portion 72, which are separated by ramp spreaders 74, 76. The ramp spreaders may include hydraulically or pneumatically actuated inserts (not shown) which allow lateral movement of the right-hand and left-hand portions 70, 72 away from one another. The ramp spreaders 74, 76 are of sufficient length to allow the ramp to straddle a railroad track located between the portions 70, 72. The spreaders are

preferably of a length sufficient to allow support of the right side and left side trailer wheel assemblies on the ramp portions.

The ramp portions of the right-hand portion 70 are formed of flat, rigid members 80, 82, 84. The left- hand portion 72 has corresponding flat, rigid members 80a, 82a, 84a. As seen more clearly in Figure 6, the flat members 80, 84 of the ascending portion 64 and descending portion 68 are of sufficient width to support one wheel of the wheel assembly. The flat member 82 of the elevated portion is of sufficient width to support two tires of the wheel assembly.

The ramp 62 is made portable by providing ramp wheel assemblies 86, 88. The wheel assemblies 86, 88 include wheels 90, 91, 92, 93 and ramp axles 94, 95 positioned between the wheels. The ramp axles 94, 95 are spring loaded to allow the ramp to move vertically downward over the wheels when the weight of the trailer is on top of the ramp. Longitudinal members 96, 97 are also included for structural support of the wheel assemblies. The wheel assemblies allow movement of the ramp away from the railtruck when not in use for assembly of intermodal systems.

For proper positioning of the railtruck with respect to the trailer, wheel stops 100, 101, 102, 103 are provided at four locations on the ramp. For example, the stops 100 and 102 locate a railtruck in the recess between the ramp portions 70 and 72. As shown in Figure 3, fairly precise positioning of the railtruck is necessary to assure proper coupling of the trailer to the railtruck. In the preferred embodiment, with the seven degree angle of elevation of the ascending portion with respect to the

ground, the wheel stop is located thirty-three (33) inches from the edge of the elevated portion of the ramp. This positioning allows a transverse rigid bar 60 to contact the railtruck and cause it to begin rolling with the trailer as the trailer wheel assemblies 14 begin to travel the descending portion 84 of the ramp. Each of the ascending, elevated and descending portions of the ramp preferably extends 114 inches in length as measured along the horizontal. To assist the mobility of the ramp unit, hinges

110, 111, 112, 113 are provided on the ascending and descending portions of the ramp. The hinges permit the folding of the ends of the ramp in a raised position to allow transportation of the unit around the railyard. To transport the unit, the ramp may be pulled by a hostler 55 or may be lifted by a forklift truck or other suitable means. For this purpose, forklift pockets 114a, 114b are provided.

Four threshold engagement plates 115, 116, 117, 118 are provided at the ends of each ramp portion to assist the backing of the trailer onto the ramp. The plates are each hinged to the ramp. The threshold plates assure contact of the ramp with the ground before the weight of the trailer forces the ramp into ground contact. The details of the construction of the ramp are shown more clearly in Figures 7-13. In Figure 8, the bottom portion of the ramp is shown in detail. A ramp side plate 120 is shown welded at a weld 121 to a bottom plate 122. Treads 123 are placed on the underside of the bottom plate 122 to assist holding of the ramp in position against the ground. Tubing 124 is interposed between the

bottom plate 122 and the bottom cross plate 126 for structural support. The plates and tubing are secured by any suitable means, such as welding.

In Figure 9, the upper portion of the ramp is shown in detail. The ramp side plate 120 is shown connected to the flat, rigid member 82 by an L-shaped bracket 128. The L-shaped bracket 128 provides support for the wheel guide member 130. The angle of the wheel guide member acts in the same manner as a highway median barrier wall to direct the wheels of the trailer to the center of the ramp. As shown in Figure 10, the wheel guide members are preferably only on the outside of the ramp portion. Treads 131 are applied to the upper surface of the rigid member 82 to aid traction of the hostler wheels. Tubing 132 is interposed between the L-shaped bracket 128 and the upper cross plate 134 for structural support. As in the bottom portion of the ramp, the plates and tubing are secured by any suitable means, such as welding. In Figures 10 and 11, the cross-section of the ramp is shown in greater detail. The tubing 124 and 132 is shown supporting both the center and the sides of the ramp portion at the top and the bottom. C-shaped support members 140 also provide structural support between the top and the bottom of the ramp.

In Figures 12 and 13, the details of a system of rail indicators are shown. The rail indicators are flat bars 142, 144 having sufficient length to extend from the surface of the elevated portion of the ramp to a point beneath the top surface of the rail track 16. The tops

146, 148 of the indicators are shown in Figure 6. The rail indicators may be spring loaded (not shown) and have

rounded bottoms. The rail indicators slip into the space next to the rail tracks, as shown in Figure 13, when the ramp is properly positioned over the rail. The indicators also provide a means of retaining the ramp in a fixed position with respect to the rail during the trailer-bogie coupling operation.

An alternate embodiment of the ramp system is shown in Figure 14. The ramp includes flat, rigid members along the ascending portions 80b, 80c, elevated portions 82b, 82c, and descending portions 84b, 84c. The ramp is similar in structure to the embodiment of Figure 6, and includes the structure previously described, with several significant differences. The ramp spreaders 74b, 76b, have been moved outboard of the wheels 90b, 91b, 92b, 93b. The longitudinal members 96, 97, shown in the Figure 6 embodiment, have been eliminated.

Similarly, the wheel stop members 100, 101, 102, 103, shown in Figure 6, have been eliminated. The location of the railtruck with respect to the trailer for coupling is determined by interference of the railtruck sideframe with the descending portion of the ramp. The railtruck is moved as close as possible to the trailer and is in the proper position for coupling once the bottom portion of the side frame interferes with the ramp. Thus, the interference condition between the ramp and the railtruck serves as the wheel stop means. With the elimination of the wheel stop members, the rail indicators 146b, 148b are moved to the outside of the elevated portions. The embodiment of Figure 14 also includes a tow bar 150, which may be used with the embodiment of Figure 6. The tow bar 150 includes a base member 151 which is

connected to the ramp by pivots received in bearings 152, 153. The bar itself includes an outside member 154 and inside member 155, with the inside member telescoped within the outside member. A tow hook 156 is provided at the end of the inside member for connection to a hostler or other tractor for transport around the railyard.

For use in conjunction with the ramp system, the present invention provides a trailer suspension system which retains the wheel assembly against the trailer. The preferred embodiment includes a limited free-play suspension system which is commercially available from Hutchens Company or similar suspension manufacturers. The limited free-play suspension system uses steel bushings and limits the downward movement of the suspension system. This retains the wheel assembly against the trailer during the rail mode operation.

An alternative embodiment of the wheel assembly retention system is set forth in Figure 15. The wheel assembly 14 is shown attached at a first end to cables 160a, 160b. The cables are wrapped around sheaves 162a, 162b and have their other ends attached to spring devices 164a, 164b. Each spring device includes a standard coil spring 166 set within an enclosure 168. The spring device is secured to the suspension frame or the like. When the wheel assembly is raised off of the ground, as in the rail mode, the springs act to pull the cables and raise the wheels off of the ground and retain the wheel assembly against the trailer.

Other alternative embodiments of the wheel assembly retention system would include, for example, the use of a sliding bar along the frame of the trailer. A

plurality of hook assemblies included on the bar would hold the wheel assembly in a raised position while the trailer was in the rail mode.

In operation, the ramp system raises the level of the trailer to allow coupling of the trailer to the railtruck bogie for assembly of the intermodal system. The ramp is placed in position along the railtrack. The ramp may be moved by the hostler or a fork lift truck so the ramp spans or straddles the track. The ramp indicator means assist in determining when the ramp is in the proper position.

Once the ramp is in position along the track, the ascending and descending portions are lowered over the hinges 110, 111, 112, 113 and the threshold plates are lowered into position. With the ramp in position, the railtruck is moved into position against the wheel stops or against the descending portion of the ramp.

The trailer is then moved by the hostler around the rail yard and backed into position at the front of the ramp ascending portion. The trailer is then backed up the ascending portion of the ramp onto the elevated portion. Only the outside wheels of the trailer contact the ascending portion of the ramp as the trailer ascends the ramp. Once on the elevated portion of the ramp, both outside and inside wheels of the trailer are supported by the ramp. As the trailer ascends the ramp, the weight of the trailer forces the bottom plate 122 of the ramp into contact with the ground. Guide means on the ramp direct the wheels of the trailer to the center and keep the wheels on the ramp.

To couple the trailer with the railtruck, the trailer is backed further over the ramp and down the descending portion of the ramp. As the trailer begins its descent down the descending portion of the ramp, the transverse rigid bar or a similar member contacts the railtruck and starts the railtruck moving in the same direction at the same rate as the trailer. In the preferred embodiment, the transverse bar begins to contact the railtruck as the center of the wheel of the wheel assembly begins to travel down the descending portion. During this movement, the trailer couples with the bogie by the interconnection of the two previously-described coupling portions.

Decoupling of the trailer and railtruck is preferably accomplished in the following manner. The train of trailers is first pulled to a location for decoupling. The landing gear on the foremost trailer is lowered to the ground and the locomotive and coupler is then decoupled and driven away. The ramp system assembly is then positioned on the track ahead of the wheel assembly of the first trailer. The hostler tractor is attached to the first trailer by the fifth wheel of the hostler. The landing gear on the next trailer is then lowered to the ground. The first trailer is then decoupled from the second trailer by release of the coupling pins and the first trailer is pulled by the hostler tractor up the ramp. The hostler must traverse the ramp followed by the trailer. The trailer, when pulled forward, can thus be decoupled from the railtrucK when its highway wheels contact the descending portion of the ramp, raising the

trailer off the railtruck bogie. The trailer is then free from the railtruck bogie and each can be used in separate operations.

Second Embodiment

Figures 16 through 32 illustrate a second embodiment of the invention. Referring now to Figs. 16 through 18, the ramp 201 generally comprises a grating or deck 203 defining an ascending portion 205, a central platform 207, and a descending portion 209. The ramp 201 is shown straddling a railroad track comprising rails 211 and 213, and is located with respect to the rails 211 and 213 by railroad wheels 215, 217, 219 and 221 shown in phantom in Figure 16. The ramp 201 also has yard wheels 223, 225, 227, 229. The frame of the ramp 201 includes side frames

231 and 233 running the length of the ramp and transverse beams 235-251 bridging between and welded to the facing side frames 231 and 233. Each transverse beam 235-251 is C-shaped or l-shaped in cross section and so has an upper flange such as 253 and a lower flange such as 255, shown in reference to the transverse beam 243. Longitudinal load bearing beams such as 257 are supported on the respective lower flanges of transverse beams such as 241 and 243 and are welded to the transverse beams. The longitudinal beams such as 257 are covered by grates which are as thick as the vertical distance between the tops of the longitudinal beams such as 257 and the tops of the upper flanges such as 253 of the transverse beams such as 243. Thus, the composite of the grates and the upper flanges such as 253 define a smooth surface on which a

trailer can be driven. Attached to the lower flanges such as 255 of several of the transverse beams are feet 259, 261, 263, 265, 267, 269, and 271 illustrated in Figure 18, as well two other feet not visible in Figure 18 (behind the wheels 225 and 229). The feet 259-271 define a horizontal plane, shown as G ¹ in Figure 18.

The ramp 201 has three significant elevations, illustrated in Figure 18. When the yard wheels 223-229 are lowered, the feet 259-271 and the rail wheels 215-221 are all raised above the railhead level G of the rails 211 and 213. The feet 259-271 are raised to level G", and the railroad wheels 215-221 are suspended slightly lower. This prepares the ramp to be transported anywhere in the yard, whether on, off, or across a railroad track. The ramp can be drawn onto a railroad track and located in the proper position with respect to the rails such as 211 and 213. When the yard wheels such as 229 are fully raised, to the position shown in phantom in Figure 18, the rail wheels 215-221 are in contact with the rails 211-213, but the feet 259-271 are at level G', still slightly above the railhead level G. When a trailer is then backed onto the ramp 201, as in Figure 19, spring loading between the railroad wheel assemblies and the frame allows the ramp to settle so the feet 259-271 contact the railhead at level G. Thus, when a trailer is actually on the ramp, the ramp is supported by its rigid frame directly upon the rails. The mechanism for selecting among these three levels is described below.

Another feature of the ramp shown in Figs. 17 and 18 is a set of thresholds 273, 275, 277, 279, and 281, which are pivotably attached to each end of the ramp and are spring loaded so their ends coast above the ground

except while a trailer is driven on them. The ramp also has left and right guide rails 283 and 285, which in this embodiment are flared somewhat outward on the descending portion 209 and substantially outward on the ascending portion 205, as shown in Figure 17. These flares make it easier to back the trailer onto the ascending ramp or to drive the hostler and trailer forward onto the descending ramp, respectively to assemble or disassemble a train. The trailer 289 has precisely the same construction as the trailer shown in the first embodiment of the invention. Referring first to Figure 19, the tractor trailer rig generally indicated at 287 to be backed over the ramp 201 comprises a highway trailer 289 defining a body carried on highway wheels 291, landing gear 293 which is normally raised when the truck is operated on the highway and is lowered to support the front of the body 289 in a level position when the tractor is disconnected from the trailer. Two features of the present invention are that the landing gear can remain in this extended position while using the ramp, and that the extended landing gear will support the tongue of the trailer at the right height to receive the socket of another trailer when coupling them to form a train.

In a rail yard it is convenient to use a hostler 295 to move the trailer 289 around when assembling and disassembling a railroad train. The hostler 295 has a hydraulically raised fifth wheel assembly 297 to support the front of the body 289 and to raise the front 299 slightly to facilitate backing the trailer over the ramp. As in the previous embodiment, the highway wheels 291 have been slid forward with respect to the body 289. The body 289 also has a fitting indicated at 301 (though not

actually illustrated) and a socket 305, also not expressly illustrated in Figure 19, to receive the tongue of the trailer behind. In Figure 19, the tongue is numbered 307, the railtruck is 309, and the adapter is 311. In this embodiment, the ascending ramp portion

205 is a compound ramp, as illustrated by reference to Figs. 19 and 20. This construction is preferred so the landing gear can remain in its extended position and still clear the ramp 201 as the highway trailer is backed over the ramp 201.

When the highway trailer is brought to a railroad yard in its highway mode, the landing gear 293 is extended to support the front of the trailer when the tractor is disconnected and driven away. The hostler 295 can be coupled to the tractor without operating the landing gear, and lifts the landing gear above ground level. However, if the grade of the ascending portion 205 is as much as 7 degrees (to minimize its length), as illustrated, the ascending portion 205 must be specially configured to pass the extended landing gear when the highway wheels 291 are on the raised platform 207 and the hostler rear wheels 219 are on the ground next to the thresholds 273 and 275, as shown in Figure 19.

Referring to Figs. 16 and 18-20, the ascending portion 205 includes a first inclined portion 213, a substantially level intermediate portion 215, and a second inclined portion 217. The first inclined portion 213 is most nearly adjacent the ground, particularly at its left edge, and does not present an obstacle to the landing gear 293, which is suspended over the ground as the trailer traverses the ramp 201. When the trailer is backed to the position shown in Figure 20, the level portion 215 lies

below the landing gear 293 just before the rear wheels 219 first engage the ramp. The level portion 215 thus provides extra clearance for the landing gear 293. The second inclined portion 217 continues to the leading edge of the platform 207 defined by transverse beam 241, and does not threaten the extended landing gear. When the landing gear is traversing the second inclined portion 217, the landing gear has been lifted substantially by the hostler, which then is also on the ramp. When the body 289 is backed up completely and is resting on the wheel truck 309, and at the same time the hostler 295 is on the ramp 201, the landing gear 293 no longer has any potential to contact the ramp. Thus, the highway trailer 289 and hostler 295 can be backed entirely over the ramp and advanced to the position of the leading car of the partially assembled train.

Another feature of the invention illustrated in Figure 18 is that the descending portion 209 is much shorter and steeper than the ascending portion of the ramp. This is possible because the highway trailer is raised above the descending portion 209 of the ramp on the adapter 311. Only the hostler 295 fully traverses the descending portion 209 of the ramp.

Another feature of the ramp 201, and particularly the descending portion 209, is illustrated in Figs. 17 and 21. The ramp 201 is surfaced between its guide rails 283 and 285. It is necessary to interrupt this continuous surface to prevent interference between the driving surface of the ramp and the rail wheels 321 and 323 of the leading axle of the railtruck 309. Recesses 325 and 327 are provided to receive the respective wheels 221 and 223. Interference between the

side frames such as 329 of truck 309 and the ramp surfaces outside the recesses such as 327 will prevent the railtrack 309 from rolling too far forward. This interference also provides a visual indication to the operators that the railtruck is located in the proper position for coupling to the highway trailer 289.

Figure 21 also shows an alternate towing tongue 331 which is a substantially flat plate attached to the surface of the ramp (preferably low on the descending portion 209). When retracted, as shown in Figure 21, the tongue 331 lies flat on the descending portion 209 of the ramp so it can be driven over without harm and the landing gear 293 will clear it. The tongue 331 is carried on a pivot 333 by pin brackets 335 and 337 so the tongue 331 can be swung longitudinally to extend its towing ring 335 substantially beyond the descending portion 209 of the ramp 201. The ramp 201 may then be towed by hitching it to a utility hitch on the hostler 295 or another vehicle. Figs. 22-28 show the details of one pair of the railroad wheels, such as wheels 215 and 217. The

"railroad wheel assembly" of the ramp is defined herein as all the structure associated with the four wheels 215-221, so Figs. 22 and following show half of the railroad wheel assembly. The rail wheels 215 and 217 are much smaller than conventional railroad wheels, such as those on the wheel truck 307. They are undersized both to save weight and so they will not project through the ramp. Each rail wheel, such as 215, is rotatably carried on a stub axle such as 337 by wheel bearings. The axle 337 is received in a stationary guide tube 339 which in turn is welded to the webs 341 and 343. The wheels such as 215 are thus

supported in fixed relation to a U-shaped channel 345 having vertical side walls 347 and 349 extending from a bottom plate 351.

The vertical position of the rail wheels 215 and 217 is regulated as follows. Referring to Figure 23, the longitudinal beams 353 and 355 and the spring bearing plate 357 are all fixed with respect to the ramp frame. The lower extremity of travel of the channel 345 is defined by the limit chains 359 and 361. Working against the limit chains 359 and 362 are telescoping spring chambers 363 and 365. The internal construction of the spring chambers is shown in Figure 24. The spring chamber 365 contains a spring 367 which bears between the spring bearing plate 358 and the channel bottom plate 351. When the railroad wheels 315 and 317 are free to travel downward, the springs such as 367 lower the channel 345 to the extent allowed by the chains 359 and 361. The compression springs 367 are sufficiently strong to support the entire weight of the ramp with the rail wheels such as 215 and 217 on the rails 211 and 213. (The springs 367 can allow slack in the chains 359 and 361 without departing from this relationship.)

Referring to Figure 18, before a trailer is driven on the ramp 201, the feet 259-271 are supported at level G ¹ , slightly above the level G of the railhead by the springs such as 367. However, the additional weight of a trailer driving on the ramp 201 overcomes the upward bias provided by the springs such as 367, urging the feet 259-271 fully against the railhead and fixing the ramp in place when the trailer is being driven on it. When the ramp is raised onto its yard wheels, as described

previously, the rail wheels such as 215 and 217 are suspended above the rails by the chains 359 and 361, allowing the wheels to be lifted cleanly off the rails. Turning now to Figs. 25-28, the chocking means for the rail wheels such as 217 will be described. Referring first to Figure 28, the rail wheel 221 is located on the track 213, and chocking means defined by chocks 369 and 371 and associated structure can be switched between a first position shown in phantom, allowing rotation of the wheel 221 so the ramp 201 can run on the rails 211 and 213, and a second position shown in solid lines, preventing rotation of the wheel 221 on the track 213. The linkage providing this capability is shown in Figs. 25-27. Each chock such as 369 is pivotally connected to a vertical link 373, which in turn is welded to a bushing 375. The bushing 375 is retained on the bolt 377 by a lock nut 379. The bolt 377 and nut 379 fix the bushing 375 to one end of a (nearly) horizontal link 381. The opposite end of the horizontal link 381 is turned to provide a flange 383 which is apertured to receive the shaft of a bolt 385. The horizontal link 381 is carried on a pivot defined by the nut and bolt assembly 387.

A cable 389 has a substantially vertical run, extending downward from the bolt 385 and led around the axle tube 339, and a substantially horizontal run 391, also shown- in Figure 17, extending to, wrapped around, and fastened to a windlass rod or drum 393. Another horizontal run, 392, continues on the other side of the windlass rod 393 and extends to a identical chocking arrangement controlling the rail wheel 217. The windlass

rod 393 shown in Figure 17 is carried rotatably on its axis by the sleeve brackets 395 and 397 and is turned at each end to form handles 399.

The chocks 369 and 371 are normally biased into their second position preventing rotation of the wheel 221 by springs such as 401 having a first end secured to a lug 403 welded to the bushing 375 and a second end secured to a lug 405 welded to the portion of the axle tube 339 outside the plate 341. The chocks are released as follows (with reference to Figs. 17 and 25-28) to shift the chocks 369 and 371 into their raised positions in which they do not affect the rotation of the wheel 221. The windlass rod 393 is rotated by throwing either handle 399 from its position shown in full lines abutting the stop 407 to its position shown in phantom abutting the stop 409. Shifting the handle in this manner draws the runs 391 and 392 toward the windlass rod 393 by winding the respective runs thereon. (Since the cable is attached to the windlass rod 393, the respective runs 391 and 392 will be wound in opposite directions, proceeding axially from the point of attachment of the cable.) Drawing the run 391 of the cable 389 draws the nearly vertical run of the cable 389 downward, thus drawing the bolt 385 and the flanges such as 383 downward, thus pivoting the bushing 375 upward along the circumference of a circle defined by the center of the bolt 387. This movement swings the vertical link 373 about an axis centered on the bolt 387, moving the chock 369 upward and outward with respect to the wheel 221. (The degree of movement is exaggerated in Figure 28.) The weight of the handles 399 works against the bias of the springs such as 401 to keep the chocks 369 and

371 raised. The chocks are set by reversing the handles 399, thus slackening the cable and causing the springs such as 401 to engage the chocks.

In this embodiment, railroad wheel chocks are only provided for the wheels 217 and 221. Chocking means could be provided for all four railroad wheels within the scope of the present invention. The function of the wheel chocks is to prevent the ramp from rolling on the railroad tracks while the trailer 289 is being driven onto the ramp, before the ramp is fully engaged with the ground due to the weight of the trailer. The chocks are raised when the ramp is to be moved along the track.

Figures 29-32 show details of the yard wheel 229 and the corresponding yard wheel suspension of the ramp. A similar suspension is provided for each of the four yard wheels 223, 225, 227, and 229. The relation of the wheel suspensions to the frame can be seen in Figure 17.

The yard wheel 229 has a pneumatic tire, and is similar to the undriven wheels used on automobile trailers or the like. The yard wheel 229 is carried on conventional bearings by a spindle 411 received in an axle tube 413 which is welded to and thus fixed with respect to a crank arm 415. The other end of the crank arm 415 is fixed to a tubular shaft 417. The shaft 417 is carried by sleeve brackets 419 and 421 and is rotatable within the sleeve brackets on its own axis. The sleeve brackets 419 and 421 are welded to the frame of the ramp. An inner crank arm 423 is also secured to the shaft 417. The shaft 417 is captured to prevent axial movement because the crank arms 415 and 423 bear against the outside faces of the sleeve brackets 419 and 421. As Figs. 30 and 32 illustrate, the sleeve brackets 419 and 421 are made in

two parts joined by fasteners so the wheel and crank assemblies can be released from the frame by undoing the fasteners.

A suitable device, such as an inflatable air pillow or pneumatic cushion 425, bears between a bearing plate 427 and fixed portions of the ramp frame, represented by the surface 429. The bearing plate 427 has upturned flanges 431 and 433 pivotally connected by fasteners 435 and 437 to the crank arms 415 and 423. When the pneumatic pillow 425 is deflated, the mechanism is positioned as shown in solid lines in Figure 31. The weight of the ramp lowers it with respect to the spindle 411 and therefore the wheels such as 229 are raised relative to the ramp by rotation of the cranks 415 and 423. Inflating the pneumatic pillow 425 urges the bearing plate 427, and therefore its pivots 435 and 437, downward with respect to the frame, which rotates the crank arms 415 and 423 against the weight of the ramp so the spindle 411 and the yard wheel 229 are lowered. The pneumatic pillows of the four yard wheels 223-229 are connected to a single source of compressed air, so all four yard wheels move in unison. The wheels such as 229 bearing against the ground when the pneumatic pillow 425 is fully inflated lift the frame up to the fully raised position shown in Figure 18 in which the feet 259-271 are raised to elevation G". This lifts the rail wheels 215-221 above the tracks 211 and 213. The ramp can then be towed freely in any direction on, off, or across the rails.

Another desirable feature of this embodiment is that when the chocks 369 and 371 are raised and the yard wheels 223-229 are not deployed to raise the ramp 201 off its rail wheels 215-221, the rail wheels are free to roll

on the rails 211 and 213 to move the ramp 201. The ramp will not require realignment with the rails 211 and 213 after it is moved in this manner. To facilitate movement of the ramp 201 in this manner, each end of each guide rail 283 and 285 can be fitted with a push plate such as 435 (Figure 18). the push plate can be engaged by a bogie handler or another yard vehicle to push the ramp 201 along a railroad track.

Thus, a ramp system for coupling a trailer to a railtruck has been provided which meets the aforestated objects of this invention. The ramp is portable and provides both an ascending portion and a descending portion. The ramp eliminates the need for an air suspension in each trailer to raise the level of the trailer for coupling to the railtruck. The ramp has wheel stops to allow precise location of the railtruck with respect to the trailer for coupling.

While preferred embodiments of the invention are illustrated, it will be understood that the invention is not limited to these embodiments. Those skilled in the art to which the invention pertains may make modifications and other embodiments employing the principles of this invention, particularly upon considering the foregoing teachings. Such modifications and other embodiments are considered within the spirit and scope of the present invention.