US3738280A

US3738280A - Beam-track assembly for air-lift or magnetic-lift vehicles

Info

Publication number: US3738280A
Application number: US00047971A
Authority: US
Inventors: M Barthalon
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-07-18
Filing date: 1970-06-22
Publication date: 1973-06-12
Anticipated expiration: 1990-06-12
Also published as: CA950946A; DE2031057A1; GB1291620A; FR2053827A5

Abstract

This invention relates to an improved beam-track assembly for land vehicles of the air-lift or magnetic-lift type, wherein the track and beam constitute separate units joined together by connecting and adjusting means. Said means preferably comprise a layer of deformable material which is disposed between track and beam and is capable of working in compression and in extension. In an advantageous embodiment of the invention, the track is tensioned at the time of erection by means of longitudinal adjusting shims so as to produce a prestress within the beam ; the upper chord of said beam is maintained in compression and the lower chord is subjected to a higher compressive stress which counteracts the oppositely-directed stresses resulting from the passing of vehicles.

Description

o I United States Patent 1191 [111 3,738,20 Barthalon June 12, 1973 [54] BEAM-TRACK ASSEMBLY FOR AIR-LIFT 3,361,084 1/1968 Ellzey 104/89 0 MAGNETIC LIFT VEHICLES 1,422,473 7/1922 Phillips 16/94 R 3,346,909 10/1967 Blackburn 211/162 [76] Inventor: Maurice Barthalon, 78, Avenue Mam, Pans France Primary Examiner-Gerald M. Forenza 22 i June 22 197 Assistant ExaminerD. W. Keen Attorney-Young & Thompson [21] Appl. No.: 47,971

[57] ABSTRACT Foreign Application Priority Data This invention relates to an improved beam-track as- July 18, 1969 France 6924644 sembly for land vehicles of the air-lift or magnetic-lift type, wherein the track and beam constitute separate [52] [1.8. CI 104/23 FS, 104/123 units joined together by connecting and adjusting [51} Int. Cl. B6lb 13/08 means. Said means preferably comprise a layer of de- [58] Field of Search 211/162; 16/87, 94, formable material which is disposed between track and 16/95; 104/23 FS, 134, 89, 123, 124; 238/283 beam and is capable of working in compression and in extension. [56] References Cited In an advantageous embodiment of the invention, the UNITED STATES PATENTS track is tensioned at the time of erection by means of 3,576,293 4/1971 Landis 238/283 longitudinal adjusting Shims so as to Produce a 3,225,228 12/1965 Roshala.. 104/23 FS prestress within the beam the upper chord of said 2,088,430 7/1937 Melles 104/123 beam is maintained in compression and the lower 3, H1965 Mackie 104/23 F5 chord is subjected to a higher compressive stress which g i f counteracts the oppositely-directed stresses resulting ar e 9 592,940 11/1897 Lee 104/124 from the passmg of vehcles' 3,511,186 5/1970 Barthalon 104/23 FS 5 Claims, 19 Drawing Figures PATENTEUJUNI 2l973 SHEET 1 OF 5 PAIENIE JUN 1 2 I973 SHEET 0F 5 BEAM-TRACK ASSEMBLY FOR AIR-LIFT OR MAGNETIC-LIFT VEHICLES This invention relates to an improved beam-track assembly for land vehicles of the air-lift or magnetic lift type.

Lift production in these vehicles results from a wall effect. Air lift can take the form of repulsion as in the case of air-cushion trains or of attraction in the case of trains under a suction air layer as described in US. Pat. application Ser. No. 607,184 filed Jan. 4, 1967, now abandoned. Where applications involving magnetic lift are concerned, one example is provided by US. Pat. application No. 697,089 filed Jan. 11, 1968, now abandoned, in respect of Electromagnetic device for producing a mechanical action.

In one known type of track for wall-effect vehicles, the track issupported above the ground by means of columns and is referred to as self-supporting. In other words, the track is intended not only to guide the vehicles which run on said track and to carry the load of a vehicle at any point of its travel but also to perform the function of a beam which distributes in the supporting columns all the live loads and dead loads of the installation. However, it is necessary for reasons of safety and comfort of passengers to ensure that the-track is constructed and located in accordance with much closer tolerances than those which are usually permitted in beams of comparable span and strength. Compliance with these tolerances results in abnormally high construction costs.

Self-supporting tracks include another known type in which means are provided for adjusting the height between the track and the supporting columns, especially in order to guard against any subsequent ground deformation bottom below said columns. The position location of the columns is thereby simplified to some extent; but the regulating means are of fairly low efficiency since they are placed at substantial distances from each other and produce action only along a vertical axis. Moreover, these means do not provide any remedy for long-term deformations of tracks which may be expected in particular when the construction of these latter involves the use of concrete.

Further difficulties also arise from the fact that an appreciable proportion of routes to be followed by vehicles consists of curved sections (usually between and 50 percent of the, total). In consequence, large numbers of special and. costly tools are necessary for the construction of tracks having characteristics which correspond to the radii of the different curves of the layout.

The object of the present invention is to overcome the above-mentioned disadvantages of self-suporting" tracks.

In accordance with the invention, the beam-track assembly for land vehicles of the air-lift or magnetic-lift type in which sustentation in produced by attraction or repulsion resulting from a wall effect, said track being also provided with flanges for supporting vehicles .when stationary, is characterized in that the track and the beam which serves as a support for said track constitute two separate units which are joined together by connecting and adjusting means.

Separation of the track from the beam and insertion of the adjusting means between these latter permits better adaptation of each component to its own function. It is then possible to employ the material and the shape which is best suited to either one or the other, to adopt dimensions in relation to the service which is required, to permit wider tolerances in the majority of cases and to facilitate both positioning of the track in curved sections and maintenance of its stability in time.

In one advantageous embodiment of the invention, the connecting means between the track and the beam are elastic and comprise in particular a layer of deformable material which can work either in extension or in compression.

Said material can thus transmit stresses from the track to the beam and can either be flattened by compression or released according to the setting which is given to the connecting means.

In a preferred embodiment of the invention, the track is tensioned at the time of erection by connecting means such as longitudinal-adjustment shims, thereby producing a state of prestress in the beam and consequently modifying the stress exerted on the beam components, especially when vehicles are passing.

The structure of the beam-track assembly can thus be lightened and its cost price reduce to an appreciable extent.

Further properties of the invention will become apparent from the description which now follows, reference being made to the accompanying drawings in which a number of particular forms of execution of the invention are shown by way of non-limitative example, and in which FIG. 1 is a transverse sectional view of a first embodiment of the invention;

FIG. 2 is a diagrammatic view of the beam which forms part of the same embodiment, this view being taken in side elevation and on a smaller scale than FIG.

FIG. 3 is a fragmentary sectional view taken along line III--llI of FIG. 1 and on a smaller scale than this latter;

FIG. 4 is a transverse sectional view of a second embodiment of the invention;

FIG. 5 is a view of the same embodiment, this view being taken in perspective and on a smaller scale than FIG. 4;

FIG. 6 is a diagrammatic view in side elevation and on a small scale showing the respective arrangement of the expansion joints of the track and of the beam;

FIG. 7 is a highly simplified diagram on a small scale showing the elastic deformations of the beam between two consecutive supporting columns;

FIG. 8 is a fragmentary sectional view taken along line VIII--VIII of FIG. 4 and on a larger scale than this latter;

FIG. 9 is a transverse sectional view of a third embodiment of the invention;

FIG. 10 is a transverse sectional bodiment of the invention;

FIG. 11 is an enlarged fragmentary view of FIG. 10;

FIG. 12 is a view in side elevation of a fifth embodiment of the invention;

FIG. 13 is an enlarged fragmentary view of FIG. 12;

FIG. 14 is another enlarged fragmentary view of FIG. 12;

FIG. 15 is a transverse sectional view taken along line XV-XV of FIG. 12;

view of a fourth em- FIG. 16 is a fragmentary transverse sectional view on a larger scale than FIG. 15 and taken along line XVI- -XVI of FIG. 14;

FIG. 17 is a fragmentary sectional view which is similar to FIG. 16 and taken along line XVII-XVII of FIG. 12',

FIG. 18 is a highly simplified diagram on a small scale and showing the forces exerted between two consecutive columns on a beam-track assembly of the type shown in FIG. 12;

FIG. 19 is a transverse sectional view of a sixth embodiment of the invention.

In a first embodiment of the invention which is illustrated in FIGS. 1 to 3, the track comprises two horizontal sustentation or lift faces 1 which are located on each side of a longitudinal track; the track is in turn provided with two vertical guide faces 2 which are joined to each other by a horizontal element 3. Each face 1 has an extension on the external side of the track in the form of a U-shaped flange 4, the opening of which is directed towards the interior of the track and the bottom or return wing 5 of which constitutes a bearing rail for the vehicles when these latter are stationary.

The beam which constitutes the track support is formed of two sheet-steel box element 6 of rectangular cross-section which are disposed at the same height and between which is formed a housing for the longitudinal track. The box elements 6 are joined together by means of a horizontal plate 7 which is located in the line of extension of the top faces of said elements and by means of a second horizontal plate 8 located in the vicinity of the longitudinal track element 3. The plates 7 and 8 which serve to brace the box elements 6 are preferably welded to these latter. Each vertical box-element wall which is directed towards the exterior of the track is preferably constituted (as shown in FIG. 2) by two sheet-steel strips 9 which are cut out on one side in the form of teeth 11 and welded in edge-to-edge relation along the extremities of said teeth; the same arrangement can be adopted in the case of the bottom walls of the box elements 6 in that portion which is located between the plates 7 and 8.

The lift faces 1 and guide faces 2 are provided with openings 12 for accommodating the heads of bolts 13 which serve to join said faces to the corresponding faces of the box elements 6. Further openings 14 for the insertion of the shanks of the bolts 13 are provided in said box-element faces opposite to the openings 12. The openings 14 are of greater width than the openings 12 (as shown in FIG. 3) and may in some cases be oval in order to provide the bolts 13 with the clearance which is necessary for adjusting the track in the vertical direction (bolts of the guide faces 2) and in the transverse direction (bolts of the lift faces 1).

A layer of deformable filling material (not shown in the figures) which is capable of working in compression and in extension is placed in a semi-permanent manner between the track and the beam and bonded to both of these latter; material such as a neoprene-base putty, for example, would be well suited for this purpose.

The vehicle 15 which travels along the track thus described is of the vacuum-lift type under a suction air layer. The vehicle is surmounted by a slide-block 16 whose profile closely conforms to that of the track. The top portion of said slide-block is provided with a central longitudinal rib 17 which engages between the guide faces 2 of the track and along the two edges with lips 18 which engage in the U-shaped flanges 4 of the track. In the stationary position, the vehicle 15 is applied by means of the lips 18 against the bottom wings 5 of the track.

In this first embodiment, the beam has a height of approximately 1.6 meters, total width of approximately 1.3 meters and a span of approximately 30 meters between consecutive supporting columns. The weight of sheet steel which is necessary in order to obtain acceptable deflection of the beam (0.03 m at a maximum) is relatively small since the material is subjected to a high working stress (of the order of 20 kg/mm).

In a second embodiment of the invention corresponding to FIGS. 4 and 5, the track is formed by means of a relatively thin sheet steel member which is bent twice at a right angle so as to form in one piece a horizontal lift face 101 and two vertical guide faces 102. In addition, the bottom edges of the guide faces 102 are bent twice at a right angle so as to form a first inwardly-directed flange and a second upwardlydirected flange, thereby constituting a vehicle guide channel 103 on each side of the track.

In this embodiment, the track is additionally provided with two horizontal bearing flanges 104 for vehicles which are at rest, said flanges being secured respectively to the guide faces 102 on that side which is directed towards the interior of the track and close to the point of junction of the guide faces 102 and the lift face 101. Said bearing flanges 104 are formed from commercially available structural sections such as angle-iron members.

The beam is constituted by two parallel side-stringers 105 which are placed on each side of the track and are preferably formed by means of l-section structural steel members of standard type. Said side-stringers can be provided with open positions (as shown in FIG. 5); they are in that case obtained by cutting-out and re-welding commercial l-beams and have a very high strength- The side-stringers are joined together at the top by means of tie-rods and are also joined by means of bolts 107 to the lower portions of the guide faces 102 and to the bearing flanges 104. Tubular distance-pieces 108 (shown in FIG. 8) surround the shanks of the bolts 107 and maintain a minimum spacing between on the one hand the side-stringers 105 and on the other hand the faces 102 and flanges 104; sets of distance-pieces 108 of different thicknesses permit transverse adjustment of the track.

Transverse strengthening members 111 are welded to the track and on the inactive sides of this latter at uniform intervals; the bolts 107 are preferably placed in proximity to said strengthening members.

The faces 102 rest by means of their guide channels 103 and if necessary by means of the strengthening members 111 on the inner and bottom flanges 109 of the side-stringers 105 with interposition of flat heightadjustment shims 112. The flanges 109 of the sidestringers 105 carry the entire weight of the track and of the vehicles both when these latter are in motion and drawn towards the face 101 and when they are at rest and bear on the flanges 104.

In this embodiment, the slide-block 116 of the vehicle has two upper lips 117 which are adapted to engage between the lift face 101 and the bearing flanges 104 in order to permit sustentation or lifting of the vehicle when this latter is stationary and two lower lips 118 which are adapted to engage in the guide channels 103 and to cooperate both for guiding and lifting at the moment when the vehicle comes to a stop.

When carrying out the erection of the beam-track assembly, the side-stringers 105 are permitted to take up their position of equilibrium under the weight of all the loads which they are intended to carry except rolling loads; at this moment, the bottom flanges 109 which support the track have a maximum deflection f (as shown in FIG. 7) at the center of the span between two consecutive supporting columns 121. Shims 112 are then placed between the track and the beam. Said shims have different thicknesses according to the distancebetween these latter and the supporting columns in order that the track should thus form a hump having a maximum counter-deflection F relative to the line 109 wherein the difference f F f represents the absolute counter-deflection. Finally, a vehicle is caused to travel along the track and F is adjusted by varying the thickness of the shims so that the longitudinal profile of the track should become substantially horizontal as the vehicle passes; f must therefore correspond to the track deflection which results from the passage of the vehicle.

In order to reduce the disadvantages arising from variations in ambient temperature, the expansion joints 122 of the track are located in displaced relation to the expansion joints 123 of the beam (as shown in FIG. 6), said joints 123 being preferably placed vertically above the supporting columns 121.

A third embodiment which is illustrated in FIG. 9 is applicable to the case of vehicles which operate on the principle of air-lift by repulsion (air cushion). The track has a general arrangement which is similar to that of the first embodiment (FIG. 1) but reversed with respect to this latter. Thus, the lift faces 201 are located beneath the corresponding faces of the vehicle and the vertical guide faces 202 are directed downwards. The track is reinforced by means of cross-members 211 which are welded to the

faces

201 and 202 on the inactive sides of these latter. The lift faces 201 of the track are supported by vertical-adjustment shims 212 on the top flanges 209 of two l-beam side-stringers 205 which are located on each side of the guide faces 202. Tierods 206 serve to join the side-stringers 205 together in the vicinity of their bottom flanges. Further tie-rods 207 serve to join the webs of the I-beam members 205 to the bottom portions of the guide faces 202by means of strengthening cross-members 211 which are welded to the track. In addition, provision is preferably made for oblique tie-rods 208 fitted with turnbuckles and located in the same plane as the tie-

rods

206 and 207 in order to endow the beam-track assembly with greater structural rigidity by means of a triangular restraint system.

This forin of construction is particularly advantageous for curved track sections. The beam is in that case made up of rectilineal elements in angularly displaced relation, variations in distance between the track and the beam elements being obtained by making use of tie-rods of different lengths from one transverse section to the other.

In a fourth embodiment of the invention corresponding to FIGS. 10 and 11, the track comprises a lift face 301 of sheet steel which terminates on each side in a U-shaped flange, the opening of which is directed towards the interior of the track. Said track is additionally provided with two substantially vertical metallic wings 302 which constitute the guide faces; the top edge 303 of each wing is bent outwards at a right angle and engaged in the U-shaped flange of the face 301, thus constituting a bearing strip for stationary vehicles.

The track is disposed within a housing formed in the lower portion of a prestressed concrete beam 305 of substantially triangular cross-section, the ridge 307 of which is located above the track; the two other vertices 308 of the triangle which are located substantially at the same height on each side of the track define the base of the beam. The prestressing elements 309 are disposed within those portions of the section which are adjacent to the vertices 308. Strengthening crossmembers 311 are also disposed at uniform intervals within that portion of the beam 305 which is comprised between the ridge 307 and the track.

The lift face 301 is attached to the housing formed for this purpose within the beam by means of anchoring lugs 310. The vertical wings 302 are attached to those portions of the beam which are adjacent to the vertices 308 by means of adjusting screws 312 which are accessible from the exterior. Said wings extend below the base of the beam and their bottom edges 304 constitute guide surfaces for the drift lips 318 of the vehicles. Transverse-adjustment shims 313 and verticaladjustment shims 314 are disposed between the wings 302 and the adjacent walls of the beam.

The catenaries 321 for supplying electric current to the motors of the vehicle are placed beneath the base of the beam on one side of the track; similarly, the signal and contral cables 322 are placed on the other side of the track.

The slide-block 316 of the vehicle 315 is provided with two upper lips 317 which engage between the lift face 301 and each top edge 303 of the metallic wings on which the vehicle rests in the stationary position. The slide-block is also provided at the lower portion thereof with two embracing drift lips 318 within which the bottom edge 304 of the wings 302 is adapted to engage; this system has the effect of completing the lateral guiding action, especially at the moment of stopping of the vehicle. The slide-block 316 further comprises current-supply slipshoes 319 which are placed in contact with the catenaries 321.

The main advantage of this form of construction lies in the fact that the beam can be fabricated in accordance with ordinary standards of concrete construction. Furthermore, by virtue of its generally triangular shape, said beam offers minimum resistance to crosswinds and does not have any surface which permits accumulation of snow. In addition, this embodiment provides the catenaries 321 as well as the signal and control cables 322 with excellent protection against bad weather conditions. Finally, this form of construction causes minimum impairment to the surroundings since the angle intercepted from the ground is smaller than in the case of a beam having a rectangular crosssection.

In a fifth embodiment of the invention corresponding to FIGS. 12 to 18, the track is obtained from a metallic sheet having edges which are bent back twice and the horizontal portion of which constitutes the lift face 401; the edges of said sheet constitute the guide faces 402 in the vertical portions thereof and bearing strips 403 for stationary vehicles in those portions which are folded back towards the interior.

The beam is constituted by a hollow prism 404 of reinforced concrete comprising an upper chord 405, two side walls or webs 406 which are preferably inclined outwards towards the base and a lower chord 407 which is of greater width than the upper chord 405 and projects relative to the side walls or webs 406.

Strenghtening cross-members 409 are welded at uni- I form intervals to the outside of the track, that is to say to that side on which the lift face 401 and guide faces 402 are inactive. Elastic clamps 411 are attached to the edges of the lower chord 407 of the beam substantially in the same transverse plane as each strengthening cross-member 409; said clamps support said members 409 by means of bolts. A number of cross-members 409 are supported by substantially vertical bolts 412 which serve to adjust the position of the track in the vertical direction (as shown in FIG. 16); a number of other cross-members are supported by bolts 413 which are directed obliquely in a transverse plane and serve to adjust the position of the track in the transverse direction (as shown in FIG. 17). i

The beam-track assembly is supported by massive clamps 414 which are disposed vertically above each column 421 and rest on these latter by means of vertical-adjustment shims 415 (as shown in FIGS. 12 and 13). Moreover, the metallic track is attached directly to the massive clamps by means of longitudinaladjustment shims 416 which are interposed between the flange 402 a of the track 402 and,the massive clamps 414 (as shown in FIG. 13), the designfunction of which is as follows At the time of erection of the beam-track assembly, the track section which is located between two consecutive columns 421 is tensioned by means of the shims 416. In consequence, by reason of the above-defined connections between the track and the beam, the lower chord 407 of the beam 404 is accordingly prestressed in spite of the load which is constituted by the total weight of the track and the beam as applied to the span considered of said beam. In FIG. 18

F designates the compressive force arising from the bending moment of the load;

F, designates the tractive force arising from the bending moment of the load;

F designates the compressive force arising from tensioning of the track;

F designates the resultant of compression on the lower chord of the beam which corresponds to the difference F F F designates the total load carried by the beam when no vehicles are present on this latter.

When a vehicle arrives on the track section considered, the weight of the vehicle which is applied to the track is transmitted to the beam 404 by means of the clamps 411, thereby modifying the stress distribution within said beam the low compression which is established within the upper chord 405 has a tendency to increase and the compression within the lower chord 407 has a tendency to decrease. If the initial tension of the track is judiciously regulated by means of the longitudinal-adjustment shims 416, there can be obtained at the time of passage of vehicles a stress distribution both within the track and within the beam such that no zone of the concrete beam will ever be in extension under load.

However, the tensile stress to which the track is subjected does not prevent this latter from carrying out by virtue of the

bolts

412 and 413 the slight lateral displacements which are necessary in order to obtain correct alignment of said track even if the beam 404 subselightening of the assembly as well as a substantial re-.

duction in capital cost.

A sixth embodiment corresponding to FIG. 19 shows that the devices according to the invention can also be carried into effect in the case of suspended vehicles or vehicles which are supported by magnetic attraction and repulsion.

FIG. 19 shows the roof of a vehicle 501 comprising a magnetic circuit 502 and induction coils 503; the magnetic circuit is interrupted by an air-gap 504 which slides along a magnetic rail 505, said rail being associated with lateral guide plates which have a low coefficient of friction.

The assembly also comprises safety hooks 507 for supporting the vehicle in the event of interruption of the current supplied to the induction coils 503.

The beam-track connecting member 508 which constitutes a reinforcement of the track 505 is connected to the supporting beam 509 by means of an adjustment device comprising fixing and adjusting bolts 510 which are adapted to slide within oval slots 511, the major axes of which are located at right angles to the track so as to permit of lateral adjustment. The adjustment device also comprises vertical-adjustment shims 514, said shims being preferably formed of elastic material which is bonded both to the top face 512 of the track and to the bottom face 513 of the supporting beam.

What I claim is 1. A beam-track assembly for land vehicles, comprising a beam, a track supported by said beam, said assembly being of the type in which sustentation is produced by lifting means acting between at least one wall of said track and at least one wall of each vehicle, said walls of said track and vehicle facing each other and being separated by a gaseous medium, said track having flanges for supporting vehicles when stationary, said track and beam constituting two separate units, said assembly including connecting means for joining track and beam together and for adjusting the position of said track relative to said beam, said connecting means including means for vertical adjustment of the track, means for transverse positional adjustment of the track and means mounting the track and beam for longitudinal displacement relative to each other, and said connecting means further including a layer of resilient material which is bonded to said track and to said beam and which is capable of elastic deformation when undergoing compressive stresses and when undergoing tensile stresses.

2. A beam-track assembly for land vehicles, comprising a beam, a track supported by said beam, said track having a substantially horizontal lift face which is downwardly directed for lifting of a vehicle by means of vacuum, means for establishing a vacuum between said downwardly directed face and at least one wall of each vehicle, said walls of said track and vehicle facing each other and being separated by a gaseous medium, said horizontal lift face of said track having at least one end adjacent to a substantially vertical guide face, adjusting elements connecting each of said faces to the beam, said track having flanges for supporting vehicles when stationary, said track and beam constituting two separate units, said assembly including connecting means for joining said track and beam together and for adjusting the position of said track relative to said beam, and said connecting means comprising a layer of resilient material which is bonded to said track and to said beam and which is capable of elastic deformation when undergoing compressive stresses and when undergoing tensile stresses.

3. A beam-track assembly according to claim 2, wherein the beam comprises two parallel side stringers located on each side of the track and connected to each other by means of tie rods.

4. A beam-track assembly according to claim 3, wherein the two parallel side stringers are metal 1- sections.

5. A beam-track assembly for land vehicles, comprising a beam, a track supported by said beam, said assembly being of the type in which sustentation is produced by lifting means acting between at least one wall of said track and at least one wall of each vehicle, said walls of said track and vehicle facing each other and being separated by a gaseous medium, said track having flanges for supporting vehicles when stationary, said track and beam constituting two separate units, said assembly including connecting means for joining said track and beam together and for adjusting the position of said track relative to said beam, said connecting means comprising a layer of resilient material which is bonded to said track and to said beam and which is capable of elastic deformation when undergoing compressive stresses and when undergoing tensile stresses, and means supporting the beam on the ground at plural bearing points spaced lengthwise of the beam, the connecting means further comprising shims disposed between two consecutive said bearing points and between the beam and the track and having thicknesses that vary according to the distance between each of said shims and said bearing points, thereby to subject the track, in the unloaded position, to a deflection which is directed upward-and the height of which, as resulting from the respective thicknesses of said shims, is such as to fall substantially to zero when vehicles are passing.

Claims

1. A beam-track assembly for land vehicles, comprising a beam, a track supported by said beam, said assembly being of the type in which sustentation is produced by lifting means acting between at least one wall of said track and at least one wall of each vehicle, said walls of said track and vehicle facing each other and being separated by a gaseous medium, said track having flanges for supporting vehicles when stationary, said track and beam constituting two separate units, said assembly including connecting means for joining track and beam together and for adjusting the position of said track relative to said beam, said connecting means including means for vertical adjustment of the track, means for transverse pOsitional adjustment of the track and means mounting the track and beam for longitudinal displacement relative to each other, and said connecting means further including a layer of resilient material which is bonded to said track and to said beam and which is capable of elastic deformation when undergoing compressive stresses and when undergoing tensile stresses.

4. A beam-track assembly according to claim 3, wherein the two parallel side stringers are metal I-sections.

5. A beam-track assembly for land vehicles, comprising a beam, a track supported by said beam, said assembly being of the type in which sustentation is produced by lifting means acting between at least one wall of said track and at least one wall of each vehicle, said walls of said track and vehicle facing each other and being separated by a gaseous medium, said track having flanges for supporting vehicles when stationary, said track and beam constituting two separate units, said assembly including connecting means for joining said track and beam together and for adjusting the position of said track relative to said beam, said connecting means comprising a layer of resilient material which is bonded to said track and to said beam and which is capable of elastic deformation when undergoing compressive stresses and when undergoing tensile stresses, and means supporting the beam on the ground at plural bearing points spaced lengthwise of the beam, the connecting means further comprising shims disposed between two consecutive said bearing points and between the beam and the track and having thicknesses that vary according to the distance between each of said shims and said bearing points, thereby to subject the track, in the unloaded position, to a deflection which is directed upward and the height of which, as resulting from the respective thicknesses of said shims, is such as to fall substantially to zero when vehicles are passing.