US3399633A

US3399633A - Convertible rail-highway tractor

Info

Publication number: US3399633A
Application number: US586057A
Authority: US
Inventors: Herscovitch William Howard
Original assignee: Herscovitch William Howard
Current assignee: UNILOKOMOTIVE Ltd 46/49 UPPER O'CONNELL ST DUBLIN; WILLIAM HOWARD HERSCOVITCH
Priority date: 1965-10-20
Filing date: 1966-10-12
Publication date: 1968-09-03
Anticipated expiration: 1985-09-03
Also published as: DE1605068B2; DE1605068A1; DE1605068C3; FR1506434A

Description

Sept. 3, 1968 w. H. HERSCOVITCH v353993533 COVERTIBLE RAIL-HIGHWAY TRACTOR Filed Oct. 12. 1966 8 Sheets-Sheet 1 FIG. 1.

INVENTOR W/[LMN l/OMEfl l/[BSCOWTCW ATTORNEYS Sept. 3, 1958 w. H. HERSCOVITCH 3,399,633

COVERTIBLE RAIL-HIGHWAY TRACTOR Filed Oct. 12. 1966 8 Sheets-Sheet 2 INVENTOE W/LU/l l7 A OWA'ED A FFSCOV/EY/ ATTORNEYS Sept. 3, 1968 w. H. HERSCOVITCH 3,399,633

COVERTIBLE RAIL-HI GHWAY TRACTOR Filed Oct. 12, 1966 8 Sheets-Sheet 3 FIG. 4.

r N v E N TOE FIG. 5. W/LL/AM HOW/7E0 #085601070/ ATTORNEYS p 1968 w. H. HERS'COVITCH 3,399,633

COVERTIBLE RAIL'HIGHWAY TRACTOR Filed Oct. 12, 1966 8 Sheets-Sheet 4 FIG. 6.

BY Q A Mm $4M ATTORNEYS P 1968 w. H. HERSCOVITCH 3,399,633

COVERTIBLE RAIL'HIGHWAY TRACTOR Filed Oct. 12, 1966 8 SheetsSheet 5 FIG. 7

\ INVENTOR W/L 1 MM yam/4E0 l/[ESCOV/El/ ATTORNEY Sept. 3, 1968 w. H HERSCOVITCH 3,399,633

COVERTIBLE RAIL'HIGHWAY TRACTOR Filed Oct. 12. 1966 8 Sheets-Sheet 6 FIG. 9.

IN VE NTOR W/LLMM HOW/7E0 #'ESCOV/I'Cf/ ATTORNEYS Sept. 3, 1968 w. H. HERSCQVITCH 3,399,633

COVERT IBLE RAIL-HIGHWAY TRACTOR Filed Oct. 12. 1966 8 Sheets-Sheet '7 HHIJIJL'JJIJ 1 NEW INVENTOR BY y Mmw

ATTORNEYS Se t. 3, 1968 w. H. HERSCOVITCH 3,399,633

COVERTIBLE RAIL-HIGHWAY TRACTOR 8 Sheets-Sheet 8 Filed Oct. 12, 1966 FIG. 77.

ATTORNEYS United States Patent ABSTRACT OF THE DISCLOSURE A rail vehicle having a longitudinally extending beam movably mounted thereon, said beam having coupler means mounted on the end thereof. Jack means mounted on the frame of the rail vehicle move the beam vertically when the coupler means is coupled to a railway car, the beam and the coupler means thus effectively function as if same were rigidly secured to the railway car coupler. The jack means permits a portion of the railway car weight to be distributed on the support wheels of the rail vehicle. Connection means between the beam and the frame permit the pushing or pulling force to be transmitted to the frame at an elevation substantially below the level of the coupler means whereby the overturning moment applied to the rail vehicle is minimized.

The invention relates to a rail tractor or locomotive primarily for spotting or shunting railway cars in railway goods yards, and more particularly to a device which is operable on or off rails. Cars as used through the specification is intended to mean any railway rolling stock suitable for the transportation of goods or passengers.

In the past; cars at sidings were moved or spotted by means of tractors fitted with nose buffers or shunting locomotives. Various single, two and four wheel machines have also been used. These previous methods and devices suffer from a number of technical, operational and economic disadvantages.

Industrial and railroad shunting operations require tractors capable of yielding a tractive effort of up to 100 lbs. per gross ton in order to cope with the most difficult rail conditions which include small radii curves and steep gradients.

The following characteristics and features are also desirable in a spotting device:

(1) Adequate loading must be provided on the driving wheels of the devices in order to utilize the available tractive effort without wheel slip.

(2) Simple means of coupling to the railway car to be moved.

(3) Stability on curves, points and crossings.

(4) Ease of removal and replacement of the device off and onto the track.

(5) Effective in extreme climatic conditions of snow, ice, floods and the like.

(6) Inexpensive in initial cost and in subsequent running and maintenance.

It is among the objects of the invention to provide a shunting device primarily for railcars which has the above capability and characteristics.

According to the invention there is provided a rail tractor comprising at least two sets of driving wheels mounted on a chassis, means for driving the wheels, a beam mounted to extend lengthwise of the chassis and pivotally secured to the chassis at a position within the wheel base of the tractor and in the vicinity of the plane of the axles of the driving wheels the beam being capable of limited vertical movement relatively to the chassis, jack means mounted in the chassis and capable of raising the beam away from the chassis, the jack means being positioned susbtantially centrally of the wheel base of the tractor, and an automatic coupler head secured to one end of the beam and extending outside the wheel base of the tractor.

A further construction of the invention involves a simple yet effective way of temporarily-for the duration of the traction operation-lengthening the automatic coupler assembly of the rail car and to affect the required coupler and weight transfer at an increased distance from the end of the railcar.

According to the invention there is provided a railway traction vehicle having a coupler head rigidly secured to a shank, the free end of the shank being pivotally secured to the vehicle chassis substantially centrally of the wheel base of the vehicle and adapted for vertical movement relative to the chassis, and jack means for raising and lowering the shank and coupler head.

The driving wheels of the tractor may have retractable guide wheels which serve as flanges mounted adjacent the driving wheels to permit removal of the tractor from the rails if desired.

The tractor of the invention may be provided with more than two sets of driving wheels, the sets of driving wheels at the end of the tractor remote from the steering wheel being provided on a common bogie. With such an arrangement the set of driving wheels adjacent the steering wheel, and the innermost set of driving wheels on the bogie are provided with flanges and the other set of driving wheels is not provided with flanges. The steering wheel or wheels are capable of raising the front end of the vehicle to an angle such that the tractor rests on the unflanged driving wheels and the steering wheels, the flanged driving Wheels being clear of the ground.

The tractor may be provided with an A.A.R. type automatic close coupler having a lifting plate secured underneath for use with close coupled cars.

The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which:

FIGURE 1 is a side elevation of one embodiment of a road/ rail tractor according to the invention, but with the coupler removed;

FIGURE 2 is a corresponding fragmentary side elevation showing a guide wheel and the actuating mechanism therefor;

FIGURE 3 is a plan view of the tractor illustrated in FIGURE 1;

FIGURE 4 is an end view of the tractor illustrated in FIGURE 1;

FIGURE 5 is a side view of part of the tractor shown in FIGURES 1 to 4, showing the automatic close coupler.

FIGURE 6 is a side elevation of a traction vehicle according to the invention;

FIGURE 7 is a plane view of part of the vehicle shown in FIGURE 6;

FIGURE 8 is a side elevation of another construction of rail traction vehicle according to the invention;

FIGURE 9 is a side elevation of a still further form of rail traction vehicle according to the invention;

FIGURE 10 is a side elevation of a yet further form of rail traction vehicle according to the invention, and

FIGURE 11 is a side elevation of a further form of traction vehicle according to the invention.

Referring to FIGURES 1 to 4 a road/rail tractor comprises a rectangular chassis comprising a pair of side members 1, 2 and a pair of end members 3, 4, all of which are steel channel-section girders. Mounted in the chassis is a first pair of driving

wheels

5 and 6 and a second pair of driving

wheels

9 and 10. The pair of driving

wheels

9 and 10 are each provided with a steel flange 7 and 8 respectively whereby the Wheels are adapted to run on rails. The pair of driving

wheels

5 and 6 are each provided with a

guide wheel

11 and 12 respectively, the guide wheels being retractable so that when the guide wheels are in their lowermost position, they serve as flanges whereby the

driving wheels

5, 6 are capable of running on rails. Alternatively, when the

guide wheels

11, 12 are retracted into their uppermost position the

driving wheels

5, 6 are then adapted for operation on a plane surface for example a road. Preferably both pairs of driving

wheels

5, 6 and 9, are provided with solid synthetic or natural rubber tires 19.

Referring to FIGURE 2, the mechanism for raising and lowering the guide wheels comprises an hydraulic jack 26 pivotally mounted at 13 to the chassis, the pistonrod 15 of the jack being pivotally secured at 16 to one arm 14 of a bell-crank 17. The other arm 18 of the bell-crank is provided at its free end with a pivotally mounted

guide wheel

11 or 12.

Mounted at one end of the chassis are a pair of retractable steerable wheels 27 which are shown in FIGURE 1 in their retracted position. The steering wheels are extendable by means of an hydraulic jack to raise the

flanged driving wheels

9 and 10 clear of the ground. The function of the steering wheels is, in conjunction with a lift and turn footing described below, to permit stepping on, off and over the rails up to any height required in practice. The steerable wheels 27 are pivoted in order to steer the tractor when it is in use on a road by means of a hand wheel 28 which operates through a

linkage

29, 30 and 31 and through a hydrostatic system whereby the effort applied by the operator to the hand wheel is magnified.

Reference numeral 35 designates a prime mover, in this case a horizontally opposed four cylinder internal combustion engine of 1200 cc. capacity, which drives a differential 34 through a clutch mechanism and a gear box 33 which may for example be provided with three forward and three reverse gears. The gear box 33 is provided with a pair of

power output shafts

36 and 37, the free ends of which serve to drive pairs of

sprockets

40, 41 and 42, 43 respectively. These sprockets in association with corresponding sprockets 44, 45 and 46, 47 and by means of chains 48, 49 and 50, 51 serve to drive the

drive wheels

5, 6 and 9, 10.

The prime mover 35 is also effective to drive an hydraulic pump 55 which may for example be a vane pump or a swash-plate pump. The pump 55 provides the power necessary for the various jacks employed by the tractor for raising the cross-beam, lowering the guide wheels, actuating the steering Wheels etc.

Mounted beneath the chassis and at a position beneath the centre of gravity of the tractor is a lift footing 56 which in FIGURE 1 is shown in its retracted position. The lift footing 56 is extendable by means of an hydraulic jack so that in its extended position it lifts the tractor clear of the ground. When the tractor is clear of the ground it may be pivoted on the lift footing either manually or by power means, for the purpose hereinafter described.

As illustrated in FIGURE 1 the tractor may also be provided with a seat 60 for the operator and a roof 61 to provide some degree of protection from the weather. It will :be appreciated however that it would be a relatively simple matter to provide an enclosed cab for the operator should operating conditions so demand.

The tractor may also be provided with a sand receptacle 62 which, by means of

pipes

63 and 64, is adapted to spray sand under the wheels in order to obtain increased traction if necessary.

It is envisaged that the tractor will normally be used on rails for shunting or spotting railcars in a goods siding. As shown in FIGURE 5 an automatic coupling device is provided on the tractor whereby it may be coupled to railcars. The automatic coupler 65, which may be of known kind, is provided with an additional plate 66 which engages the underside of the railcar coupler when the railcar and tractor are coupled whe y p ration of a jack 24 on which the coupler is mounted to raise the coupler 65 is effective to transfer part of the weight of the railcar to the tractor. A handle 67 is provided whereby a locked coupling can be disengaged from the driving seat of the tractor.

Ballast may be carried on the tractor in order to increase the tractive adhesion of the tractor, but if rubber tires are employed, as is preferred, this usually is not necessary.

When it is desired to remove the tractor from the rails, for instance when the tractor is to be used to tow road trailers, the lift footing 56 is first extended to lift the tractor clear of the rails and the tractor is turned on the lift footing 56 so that it lies at right-angles to the rails.

The steerable wheels 27 are then lowered and the lift footing 56 retracted so that the tractor rests on the ground with the first pair of driving

wheels

5, 6 outside the rails, the

flanged driving wheels

9, 10 raised from the ground and the steering wheels 27 on the opposite side of the rails. The tractor is then backed, that is to say driven in a direction with the steerable wheels 27 trailing, until the steerable wheels 27 rest against the outside of one rail. The steering wheels 27 are then retracted and the tractor backed further until the

flanged driving wheels

9, 10 contact the inside of the other rail. The steerable wheels 27 are again extended and the tractor backed still further until the steerable wheels 27 contact the inside of the said other rail. The steerable wheels 27 are again retracted and the tractor is backed away from the rails on its four

driving wheels

5, 6 and 9, 10. The steerable wheels 27 can then be extended once more so that the tractor can be steered and used as a road tractor.

If desired means can be provided for adapting the tractor for use as a crane. Additionally or alternatively the tractor may be provided with a pair of pallet forks, preferably pivotally secured to the chassis adjacent the steerable wheels 27. The forks can then be folded upward when not in use. The tractor may also be provided with brakes, preferably hydraulically operated, and preferably of substantial size. It will be appreciated that these brakes usually provide the entire retarding force, disregarding friction, when shunting a train of rail cars, as it is unusual for rail car vacuum brakes to be coupled-up when the cars are in a goods siding.

From FIGURES 6 and 7 of the drawings it can be seen that a traction vehicle of the same general lay-out as that described with reference to FIGURES 1 to 5 is fitted with a standard automatic coupler head 65 with a shelf 66 at the bottom of the jaw 68. In some cases the shelf may be omitted. To this head is attached a shank 69 which is hinged at 70 to the coupler head in a manner to permit the required angular movement of the head for travelling through curves (13 15). The shank ends with a horizontal plate 71 with a drilled hole or slot 72 in the centre.

The coupler and shank assembly floats on a coil or bar spring 73 of adequate stiffness to support the whole assembly at standard coupler height yet to permit free three dimensional movement of the assembly without transferring any appreciable loads to the traction vehicle to which the other end of the spring is attached. The spring also acts as a centering device for the coupler.

Under the shank, behind the hinge 70 which permits the horizontal angular movement of the coupler head standard to all automatic couplers, a hydraulic cylinder 74 of adequate force is rigidly mounted onto the traction vehicle frame.

The shank ends with the above-mentioned horizontal plate 71 with a drilled hole. In this hole or slot 72 is received a shaft or pin 75 of adequate strength to transfer all the horizontal loads due to traction and braking efforts without causing permanent deformation to the shaft. The shaft is rigidly attached to a frame member 76 in the middle or close to the middle of the traction vehicle, between the front and rear axles of the traction vehicle.

The said shaft is curved to a radius R corresponding the distance of the coupler line and the centreline of the drilled hole in the horizontal plate.

In order to couple and achieve weight transfer, the traction vehicle approaches the railcar and the two automatic coupler heads lock in the normal manner. Once this coupling operation has been completed the hydraulic cylinder which has a swivel jointed head 77 is raised so as to lock the two coupler heads together. The hydraulic cylinder is dimensioned so as to exert the desired vertical load on the coupler shank and this load reacts back on the traction vehicle frame and wheels giving the required additional adhesive loading. In order to ensure permanent and even load transfer and to avoid peak loads in the cylinder due to uneven tracks, a suitably dimensioned gas-filled hydraulic accumulator should be placed under the piston of the hydraulic cylinder.

Once the hydraulic cylinder has been raised there will be a slight angular displacement between the two coupler heads which is determined by the clearances of the heads and their condition of wear. The two coupler heads are locked together, and the shelf on the traction vehicle coupler head, if used, prevents any excessive upwards sliding of the coupler.

Immediately the said hydraulic cylinder has applied the required load under the shank, the traction vehicle coupler and its shank become a rigid extension of the railcar coupler and the vertical forces transferred through the hydraulic cylinder act at the centreline of the hydraulic cylinder itself instead of at the coupler line which is the case with all other known weight transfer systems where the lifting is done under the coupler head.

The traction forces being transferred to the end of the above-mentioned rigid assembly of couplers, also act at the centreline of the said shaft and therefore considerably nearer to the middle of the traction vehicle. The resultant over-turning moment acting on the traction vehicle are in this case approximately equal for both directions of travel whereas in the normal and hitherto known vehicles in which the coupling is provided at the rear, the overturning moment when pulling imposes a severe limitation on the tractive effort which can be applied without lifting the front wheels off the rails.

With this construction it is possible to achieve equal wheel loadings for the vertical loads being taken over from the railcar and also a high degree of stability against overturning moments resulting from the application of the tractive effort from the traction vehicle to the railcars to be pushed and pulled.

This construction provides a floating coupler assembly for railway vehicles which although part of the traction vehicle itself, is so attached and operated that on coupling it to the railcar coupler and by applying a force in a vertical direction under the assembly, it becomes temporarily a rigid part of the railcar permitting more advantageous coupling and weight transfer from the railcar to the traction vehicle.

Although the coupler assembly is fully secured against jack-knifing in the horizontal and vertical planes, in order to ensure that the coupler head of the traction vehicle can only swivel (when travelling through curves) at the swivel pin and thereby no lateral movement will occur in the shank extension over the hydraulic cylinder, a lateral guide frame 78, with adequate clearances, is firmly attached to the main frame. This is of sufficient height to restrain undue lateral movement of the shank for the full vertical displacement of the shank.

The lifting cylinder is mounted on the frame either rigidly as described above but in this case provision must be made for a free longitudinal sliding movement at the top end between the shank and the piston rod (in order to avoid bending stresses on the cylinder piston rod), or alternatively and preferably the cylinder is mounted with one and preferably both ends on a swivel joint.

The coil spring, although it could be fitted under any point behind the coupler head, is preferably placed under the coupler head and forward of the swivel pin so that in addition to its main function to provide a three dimensionally elastic support for the whole coupler assembly it simultaneously performs the task of centering the coupler head.

With all the known systems of coupling and weight transfer, the horizontal forces, that is to say the tractive effort of the traction vehicle when pulling or pushing, which act as overturning moments on the traction vehicle, are transferred to the railcar at a height from the rail predetermined by the height of the coupler or the height of the car frame. No known system of coupling has the ability to shift the coupler line height below that determined by the rail car coupler height.

For the most satisfactory performance, the horizontal forces should be applied to the traction vehicle at a very small distance above the rails-preferably midway between the axles. In this manner no overturning moment due to the reaction the horizontal forces can occur in the traction vehicle. This has the important advantage of permitting a constant and unvarying load distribution over the front and rear axles and wheels so that no variation in performance can occur when pulling or pushing even if the position of attack of these horizontal forces is at one end rather than in the middle of the traction vehicle.

The described invention of the floating coupler assembly which becomes with its extension shank a rigid extension of the railcar, permits the extension to be curved, downwards, or the described horizontal plate with the drilled hole (for the transfer of the horizontal forces to the frame of the railcar) can be welded at a desired point below the centreline of the coupler assembly. Thereby the forces will be transferred at that lower point. In this manner the overturning moments can, at will, either be reduced to a desired minimum or completely eliminated.

It is envisaged that the constructions shown in FIG- URES 8 to 11 will prove advantageous when applied to short wheel base locomotives in the 10 to 25 tons range since the additional 15 to 20 tons adhesive load transferred from the railcar would add between 80 to 200% to the traction capacity to the locomotive, by increasing the adhesive weight thereof.

The constructions also find application however in the small traction vehicles which typically weigh about 2.5 tons, and which are powered by small internal combustion engines.

It is a particular object of the following constructions to apply to the traction vehicle the horizontally acting forces due to pushing or pulling the railcars at a small distance above the rails so that overturning moments on the traction vehicle are minimized or eliminated.

In FIGURE 8 there is shown a rail traction vehicle of the same general lay-out as described with reference to FIGURES l to 5.

An automatic coupler head 65, which is preferably of the P type, which is provided with a shelf, is rigidly secured to a beam 69 by means of a swivel pin 70 which allows the standard horizontal limited pivotal movement in order that the vehicle may negotiate curves. From the undersurface of the beam 69 extends an arm 80, the free end 81 of which is secured to the chassis of the tractor for limited vertical and horizontal movement on a pin 82 mounted on the chassis.

The coupler head and beam assembly float, when in an uncoupled condition, on coil springs 73 at standard coupler height.

Mounted on the vehicle chassis substantially midway between the rail wheels of the vehicle is a vertical jack 74, the free end of the piston rod of which carries a roller 83 which bears on the undersurface of the beam 69 so as to raise the beam when it is coupled to a rail vehicle so as to transfer weight from the railcar to the traction vehicle.

It will be noticed that the horizontal loads due to pushing or pulling a railcar are taken through the arm and pin 82 substantially in the plane of the rail wheel axles so that overturning moments on the rail traction vehicle are minimized or eliminated.

Referring to FIGURE 9 there is shown a rail traction vehicle generally similar to that shown in FIGURE 8 with the exception that two

hydraulic cylinders

74a and 74b are provided which are trunnion mounted at 85 and 86 respectively to the vehicle chassis with their respective piston rods 87 at an angle to one another, the free ends of the piston rods being pivotally secured to a common member 88 provided with a roller 89. The roller 89 bears against the undersurface of the beam 69 so as to force the beam upwardly when the piston rods are extended. The downwardly acting force due to the weight of the coupled railcar acts substantially centrally of the wheel base of the traction vehicle.

In FIGURE 10 there is shown a short wheel base industrial locomotive provided with a weight transfer system according to the invention, comprising a pair of automatic coupler heads 65 positioned one at each end of the locomotive, each coupler head being secured to a horizontal beam 69 which extends longitudinally of the vehicle. The inner ends of the beams 69 meet at a midposition of the wheel base of the locomotive and are pivotally secured at 90 to a vertically extending jack 74 which is adapted to force the beams 69 upwardly. Secured to each of the beams 69 is a downwardly extending arm 80, the lOWer end of which is pivotally secured for limited vertical movement to the locomotive chassis at a position below the centreline of the rail wheels by means of pins 82. The beams are supported in their non-loaded position by means of coil springs 73.

It will be appreciated that when the coupler head on the traction vehicle is locked with the coupler head on a railcar, then the traction vehicle coupler head and beam assembly become a rigid extension of the railcar coupler. The railcar is then lifted as previously described by means of a hydraulic jack or jacks so as to transfer part of the Weight of the railcar to the traction vehicle. By using a downwardly extending arm mounted to form an integral part of the beam and pivotally secured to the vehicle chassis at a small height above the rails, it is possible completely to eliminate any overturning moment on the traction vehicle due to shunting or towing loads. Thus the severe limitations of the prior art, which were (i) weight transfer reaction acted in the position of the application of load, which meant that an unequal loading of the driving wheels of the traction vehicle occurred and (ii) the fact that the horizontal forces due to towing or pushing a rail car acted at the coupler height and in so doing imposed a large overturning moment on the traction vehicle, are completely avoided. With the construction of the present invention, the coupler head can project as far out from the traction vehicle as is desired since in this case it has no bearing on the load distribution over the wheels as is the case with other systems. In all other known systems the most critical point is the placing of the coupler between the front or rear axles in order to prevent the overturning of the machine when the vertical load is applied.

The construction shown in FIGURE 10 could be modified so that each beam has its own jack. In this manner both couplers can be used independently of each other.

In FIGURE 11 there is shown a road/ rail tractor of the same general kind as that described with reference to FIGURES l to of the drawings. In the drawing an automatic coupler head 65 is secured, by means of a pin 70, to a beam 69 to which is secured a downwardly extending arm 80 provided with a longitudinally extending slot 95. A guide-member or pin '96 is mounted in the slot and the ends of the pin are secured to the chassis of the tractor. The member 96 serves to absorb horizontal loads due to pushing or pulling a railcar. Secured to the arm 80 is a stop member 97 which in the lower most position of the movement of the beam abuts the bottom of a groove 98 of a member 99 secured to the chassis of the tractor. A pair of tension springs 100, the ends of which are secured respectively to the coupler head and to a casing 101 surrounding the jack 74, constantly urge the beam into a rest position. If desired further springs may be provided either below or above the beam so that beam is held in the correct horizontal position when the coupler head is not coupled to a car coupler. Alternatively guide members may be provided to steady the beam until it is coupled.

I claim:

1. A rail vehi le capable of partially supporting and capable of moving a second vehicle, comprising:

a frame;

a first pair of wheels mounted on said frame, said wheels being adapted to rollingly engage a pair of parallel rails;

a second pair of wheels mounted on said frame, said wheels being adapted to rollingly engage said pair of rails;

motor means adapted to rotatably drive said first pair of wheels;

beam means movably mounted on said frame and extending lengthwise thereof;

connection means interconnecting said beam means to said frame for permitting vertical movement of said beam means relative to said frame;

jack means mounted on said frame and operatively connected with said beam for vertically moving same;

coupler means secured to said beam means adjacent one end thereof, said coupler means being adapted to interconnect with a coupler on said second vehicle for pushing or pulling same;

said connection means including a first portion rigidly secured to said beam means coacting with a second portion rigidly secured to said frame for transmitting the pushing or pulling force applied to said coupler means to said frame, said second portion being positioned adjacent the lower portion of said frame whereby the connection means transfers the pushing or pulling force to said frame at an elevation substantially below the level of said coupler means, thereby minimizing the overturning moment applied to said rail vehicle when pushing or pulling said second vehicle.

2. A rail vehicle as defined in claim 1, wherein:

said connection means floatably mounts said beam means on said frame for permitting the entire beam means to be both linearly and angularly moved within a vertical plane relative to said frame;

whereby interconnection of said coupler means to the coupler of said second vehicle and actuation of said jack means for vertically raising said beam means causes said beam means and said coupler means mounted thereon to effectively function as if same were rigidly secured to the coupler of said second vehicle.

3. A rail vehicle as defined in claim 1 wherein:

said connection means includes pin-and-slot means coacting between said beam means and said frame for permitting vertical movement of said beam means relative to said frame.

4. A rail vehicle as defined in claim 1, wherein:

said jack means is mounted on said frame substantially midway between said first and second pairs of wheels, actuation of said jack means for raising said beam means causing a portion of the weight of said second vehicle to be transferred onto said beam means and through said jack means to said frame, whereby the portion of the weight of said second vehicle is substantially uniformly distributed on each of said wheels.

5. A rail vehicle as defined in claim 1, wherein:

said beam means comprises a first substantially horizontal portion and a second downwardly extending portion fixedly secured to said first horizontal portion;

said first portion of said connection means being rigidly secured to the lower end of the second portion of said beam means;

said connection means including a pin fixedly secured to one of said first and second portions of said connection means and a slot formed in the other of said first and second portions of said connection means, said pin being slideably received within said slot whereby said connection means permits said beam means to be vertically moved relative to said frame; and

resilient means coacting between said beam means and said frame for supporting the beam means and the coupler means and for urging the beam means and the coupler means into a coupling position.

6. A rail vehicle as defined in claim 5, further including:

second lengthwise extending beam means movably mounted on said frame in substantial alignment with said first-mentioned beam means;

second coupler means mounted adjacent one end of second beam means with said second coupler means being mounted adjacent one end of said rail vehicle and said first-mentioned coupler means being mounted adjacent the other end of said rail vehicle;

second connection means interconnecting said second beam means to said frame for permitting vertical movement of said second beam means relative to said frame;

said jack means being mounted on said frame centrally between said pair of wheels and being operatively connected with said second beam means for vertically moving same;

said second connection means transferring the pushing or pulling force applied to said second coupler means to said frame at an elevation substantially below the level of said second coupler means.

7. A rail vehicle as defined in claim wherein:

said jack means includes a pair of fluid-actuated power cylinders, each of said power cylinders being pivotally mounted at one end thereof to said frame;

a connecting member having a roller rotatably supported thereon, the other end of each of said power cylinders being pivotally connected to said connecting member;

said power cylinders being positioned at an angle to one another whereby the roller on said connecting member is maintained in contact with the undersurface of said beam means.

8. A rail vehicle as defined in claim 5, wherein:

said coupler means is mounted adjacent one end of said first beam portion for pivotable movement in a substantially horizontal plane;

said resilient means including spring means operably coacting between said frame and said one end of said first beam portion for maintaining said coupler means in a centered position; and

said jack means is positioned adjacent the other end of said first beam portion for raising said beam means relative to said frame, said jack means being mounted on said frame substantially centrally of said wheels.

9. A rail vehicle as defined in claim 1, further includa third pair of steerable and rotatable wheels, said wheel's being adapted to rollingly engage the ground; means mounting said third pair of wheels on said frame for vertical movement with respect thereto between an upper position above a plane defined by the lowermost points on said first and second pair of wheels, and a lower position wherein said third pair of wheels extends below said plane; and

lift means mounted on said frame and having a pivotable support member vertically movable between a first position above said plane and a second position below said plane for supporting the entire vehicle spaced from the ground for permitting the rail vehicle to pivot in a substantially horizontal plane.

10. A rail vehicle as defined in claim 9, wherein:

said connection means fioatably mounts said beam means on said frame for permitting the entire beam means to be both linearly and angularly moved in a vertical plane relative to said frame;

11. A rail vehicle as defined in claim 10, wherein:

said connection means includes a pin-and-slot means coacting between said means and said frame for permitting vertical movement of said beam means relative to said frame.

12. A rail vehicle as defined in claim 10, wherein:

said connection means including a pin fixedly secured to one of said first and second portions of said connection means and a slot formed in the other of said first and second portions of said connection means, said pin being slideably received within said slot whereby said connection means permits said beam means to be vertically moved relative to said frame;

resilient means coacting between said beam means and said frame for supporting the beam means and the coupler means and for urging the beam means and the coupler means into a coupling position; and

said jack means causing a portion of the weight of said second vehicle to be transferred to said rail vehicle, said jack means being positioned on said frame so that the portion of the weight of the second vehicle is substantially uniformly distributed on each of said wheels.

13. A rail vehicle as defined in claim 10, wherein:

said vehicle is supported only on said first and second pairs of wheels when in rolling engagement with said rails and is supported only on said first and third pairs of wheels when in rolling engagement with the ground.

14. A rail vehicle capable of partially supporting and capable of moving a second vehicle, comprising:

a frame;

motor means adapted to rotatably drive said first pair of wheels;

beam means movably mounted on said frame and extending lengthwise thereof;

coupler means mounted to said beam means adjacent one end thereof, said coupler means being adapted to interconnect with a coupler on the second vehicle for pushing or pulling same;

connection means floatably supporting and interconnecting said beam means to said frame for permitting vertical movement of said entire beam means relative to said frame, said connection means also permitting angular movement of said beam means in a substantially vertical plane relative to said frame; and

jack means mounted on said frame and operably connected with said beam means for vertically moving same for permitting a portion of the weight of the second vehicle to be transferred to said rail vehicle.

15. A rail vehicle as defined in claim 14, wherein:

said jack means is mounted on said frame substantially midway between said first and second pairs of wheels, the portion of the weight of said second vehicle transferred to the rail vehicle being transmitted through the jack means to said frame whereby same is substantially uniformly distributed on each of said wheels.

16. A rail vehicle as defined in claim 15, wherein:

said connection means includes a pin-and-slot means interconnecting said beam means to said frame for transferring the pushing or pulling force applied to the coupler means therethrough to said frame, said slot extending in a substantial vertical direction with said pin being movable relative to said slot in a substantially vertical direction for permitting both linear and angular movement of said beam means in a substantially vertical plane.

References Cited UNITED STATES PATENTS 1,863,575 6/1932 Moncrieif et a1 105--215 1,881,045 10/1932 Chapin et al. 105-215 XR 2,718,197 9/1955 Bock et al. 1'05215 2,721,522 10/1955 Ames 105-73 3,108,513 10/1963 Koshobu 105-215 XR 3,130,686 4/1964 Fiechter et a1. 105215 3,182,604 5/1965 Foxx et al 105177 3,198,137 8/1965 White 10526 3,249,007 5/1966 Keller 105-215 ARTHUR L. LA POINT, Primary Examiner.

H. BELTRAN, Assistant Examiner.