US3896737A - Switch for a suspension railroad - Google Patents

Abstract

An improved switch for use in a syspension railroad system utilizing the electrodynamic suspension principle in which a separate normal flux system is provided having roadway members located outboard of a suspension system for the main roadway extending from the plane of the main roadway to the plane of a branch roadway vertically displaced from the main roadway, which members cooperate with extendable and retractable members in the vehicle whereby with said vehicle members retracted travel along the main roadway results and with said vehicle members extended travel to the branch roadway results.

Description

Miericke 1 1 July 29, 1975 [54] SWITCH FOR A SUSPENSION RAILROAD 3,763,788 10/1973 Pougue 104/130 3,777,667 12/1973 Perrott 104/130 [75] Inventor: Jurgen Mlerlcke, Nurnberg.

Germany Primary ExaminerM. Henson Wood, Jr. Assigneer Siemens Aktiengesellschaft, Munich, Assistant E.raminerRichard A. Bertsch rm ny Attorney, Agent, or Firm-Kenyon & Kenyon Reilly 22 Filed: May 1, 1974 1 N 46 ,751 r [2 1 App] 5 57 ABSTRACT [30] Foreign Application Priority Data An Q FF Switch for use In syspenslqn railioafi system utilizmg the electrodynamic suspension pr1nc1- May 5, 1973 Germany 2322150 p in which a Separate normal flux System is provided having roadway members located outboard of a sus [52] U.S. Cl. 104/130; 104/148 MS pension System for the main roadway extending from hilt. the plane of the main y to the plane of a [58] Fleld 0f Search 104/130, 148 MS, 148 SS, branch roadway t ly displaced from the main 04/148 LM roadway, which members cooperate with extendable and retractable members in the vehic1e whereby with 156] References cued said vehicle members retracted travel along the main UNITED TATE P T T roadway resu1ts and with said vehicle members ex- 3,680,488 8/1972 Donlon 104/130 tended travel to the branch roadway resu1ts. 3,712,238 1/1973 Colovas et al...... 3,738,281 6/1973 Waidelich 104/148 MS 13 Clam, 3Drawmg 8" SWITCH FOR A SUSPENSION RAILROAD BACKGROUND OF THE INVENTION This invention relates to magnetic suspension railroads in general and more particularly to an improved switching arrangement for use in such railroads.

Various systems have been developed for use in electrodynamically guiding a suspended vehicle. Such suspension systems are operable with vehicle velocities of approximately 300 km/hour and more. Generally, in all of these systems, as the vehicle moves along the track, currents are induced in electrically conducting support and/or guidance elements arranged along the roadbed by superconducting magnetic coils attached to the vehicles. These elements on the roadbed comprise, for example, electrically conducting plates or conductor loops extending in the direction of travel of the roadbed, and are also referred to as reaction members. The currents induced therein exert repelling forces on the magnetic coils for supporting and/or guiding the vehicle along the track.

The simplest system of this nature is called a normal flux system and comprises a horizontally disposed conducting plate running along the roadbed over which the magnet coil moves with the magnet coil also disposed in a horizontal plane. As the magnet coil appraoches the plate, the repulsion forces become larger causing the separation between the plate and magnet coil to increase and thus hold the magnet coil suspended. In addition to the lifting forces, which oppose the force of gravity of the vehicle, braking forces are also induced due to the ohmic resistance of the conducting plate, which forces have a direction opposite to the travel direction of the vehicle.

In a paper published in the Journal of Applied Physics, vol. 43, (1972), pp. 2680-2691 by Richards et al. a system in which braking forces and losses are relatively small has been described. This system is called a zero flux system and includes superconducting magnet coils mounted on the vehicle and arranged in pairs arranged one above the other vertically. The two coils are excited in mutually opposite directions and are guided above and below an electrically conducting plate which is coupled to the roadbed and disposed generally horizontally. With such an arrangement, particularly if the plate is thin relative to the depth of penetration of the magnetic field into the plate material, low losses result. With the exception of small losses produced in the center portion which causes braking forces, only if the plate is not situated in the center between the coils of the respective coil pairs are any significant losses produced. The braking force produced is in the first approximation proportional to the square of the excursion of the center position while the lifting force produced is in the first approximation directly proportional to the excursion. As compared to other systems in order to obtain lifting forces for a vehicle of the same weight, two magnet coils are required as compared to one magnet coil in the normal flux system mentioned above. A similar zero flux system in which the support rail mounted on the roadbed is not a conducting plate but is a multiplicity of conductor loops arranged one next to the other in the direction of travel has been described in an article by Powell et al. published in the Journal Cyrogenics and Industrial Gases vol. 4, pp. 19-24, (1969).

Clearly, the cost of the installed rail line for use in suspended railroads of this nature is quite expensive. As a result, it is considered to be more economical to run a single track over long distances with appropriate branch tracks provided to permit vehicles traveling in opposite directions to pass each other. This requires the switches to be provided to guide vehicles onto these branch tracks or sidings to allow such passage. As a result, various types of switching systems have been developed. One such system requires that the vehicle be severely braked ahead of the switch to the point where it is no longer in suspended guidance. Vehicles of this nature are typically equipped with auxiliary wheels which can ride on conventional tracks during starting and stopping and in case of emergency. Thus, in this system, the vehicle is slowed down to the point where it runs in conventional fashion with wheels on tracks and is guided off the main track and onto a siding using a conventional railroad switch.

Another type of switch has been disclosed in U.S. Pat. Application Ser. No. 399,940 now Pat. No. 3,841,227. In general terms, this system comprises two U-shaped guidance channels of non-magnetic electrically conducting material which are attached to and run along the roadbed each comprising an upper and lower part disposed in planes essentially parallel to the roadbed, i.e., horizontal and a lateral part disposed approximately perpendicular thereto. Pairs of superconducting magnets are mounted on the vehicle, with at least two pairs on each side thereof, and are arranged so that one magnet of each pair is situated between the upper and lower parts of the U-shaped channels and that the second of the pair is vertically above the upper part of the channel. Thus, the lower coil in conjunction with the lower part forms a normal flux. In the area of the switch, only the lower part of the guidance channel is provided along with a movable lateral part. Thus, in the area of the switch only a normal flux system is provided to supply the necessary lateral forces. The displaceable lateral parts provide good horizontal guidance through the region of the switch. If a linear motor propulsion motor is used for propelling the vehicle, the armature rails of the linear motor are positioned along the roadway or shifted horizontally with respect to the roadway within the switch or alternatively propulsion in the switch area can be dispensed with and the switch traversed by inertia. In addition, the parts which are shifted horizontally need not consist of one piece but can be assembled in a sectional manner which section when setting the switch can then be shifted laterally to different degrees. In another embodiment, in order to set the switch the movable parts are moved down for straight ahead travel and other side parts moved up for branching off from onto the switch track.

In addition to these systems and others which permit branching off in the horizontal plane onto a track lying in the same plane, a switching system in which the vehicle is switched to a branch track in a separate vertical plane has also been disclosed. Such an arrangement is shown in the paper entitled The Magnet Plane Guided Electromagnetic Flight Model Paper," (Massachusetts Institute of Technology, Cambridge, May 1, 1972, p. l-lO). In the disclosed arrangement, a vehicle equipped with superconducting coils is guided by electrodynamic suspension in a trough shaped aluminium track. A roadway section about a mile long is mounted on sliding bearing blocks which permits the connection of the roadway with a parallel roadway which is in a horizontal plane above the normal roadway. When operating at higher speeds such as above I km/hour, large radii are required for switches of this nature and thus, mechanically movable sections of relatively long length must be provided. As a result, the apparatus for moving these long sections of track within the switch becomes extremely expensive.

In view of the deficiencies of the prior art switches, it is the object of the present invention to provide an improved switching arrangement of this general nature, which arrangement fulfills all requirements without being excessively costly.

SUMMARY OF THE INVENTION The present invention solves this problem by installing in the vehicle mechanically movable means which are capable of reacting with additional fixed means mounted on the roadbed in the area of the switch to thereby provide an additional guidance arrangement operative only within the switched area. In a first illustrated embodiment, the means mounted in a mchanically movable manner on the vehicle comprise an additonal set of superconducting coils and the means mounted on the roadbed additional conducting plates (reaction rails) to cooperate therewith to form a normal flux system. The reation rails within the switch which form part of this separate suspension system are inclined so that they can guide the vehicle upward to a branch track which is vertically above the main track in a separate horizontal plane. This switch permits contactless change fron one roadway to the other while utilizing the electrodynamic principle and is capable of supporting vehicles operating at high speeds. Furthermore, the switch has no moving parts. The parts in the vehicle which must be moved in the switched area are relatively small. As a result, the switch can have a large radius of curvature at the point where it branches off and thus can be traversed at high speeds. As a result, continuous transfer to the branch track is assured without endangering safe guidance of the vehicle.

According to a further embodiment of the invention, the auxiliary guidance system comprises magnets installed on the roadbed which cooperate with retractable reaction rails on the vehicle. This arrangement offers further advantages with regard to propulsion of the vehicle within the switch region.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross sectional view through a portion of a switch according to the present invention also illustrating the lower portion of a vehicle with respect to the switch.

FIG. 2 is a perspective view of a portion of the roadbed of FIG. 1.

FIG. 3 is a cross sectional view through an alternate embodiment of a switch according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a cross sectional view looking in the direction of travel of a switch according to the present invention. The main track right-of-way rests on aroadbed 2 with the branch track located vertically above and resting on a roadbed structure 2a supported in suitable fashion. The point at which the cross section of FIG. 1 is taken is at a point illustrated on FIG. 2. That is, it is at the point of entrance into the switch. Shown associated with the lower main track section is avehicle 1 which is assumed to be in a suspended state with respect to the roadbed. Similarly, a vehicle la is shown on the branch track located vertically above the main portion of the track. At the entrance to the switch, two reaction rail arrangements designated 3 and 4, one on each side of theroadbed 2 are provided. Thereaction rail arrangement 3 is made up of ahorizonal rail 5, avertical rail 6, anotherhorizontal rail 7 and anothervertical rail 8. Similarly, thearrangement 4 is made up ofhorizontal rails 9 and 11 and thevertical rails 10 and 12. As can be seen more clearly by viewing FIGS. 1 and 2 together, the reaction rails 5 and 6 and 9 and 10 remain in the plane of theroadbed 2 continuing on as the main portion of track. Therails 11 and 12 and 7 and 8 however, are sloped upwardly to the branch track located above theroadbed 2, i.e., to the branch track on the roadbed 2a. The reaction rails 9 and 10 and 5 and 6 are used for straight ahead travel on the main track and the reaction rails 7 and 8 and 11 and 12 for travel onto the branch track supported thereabove on the roadbed 2a. Suspension of the vehicle when on the main portion of track is obtained through the intereaction ofsuperconducting coils 13 and 14 located on opposite sides of the vehicle, with theirrespective reaction rails 9 and 10 and 5 and 6 to form a normal flux system. Shown are coils l5 and 16 located directly above thecoils 13 and 14 with a gap in between. These groups of coils can be used to form a zero flux system on straight portions of the track outside the switch at which point a reaction rail will be located therebetween. A zero flux system of this nature is disclosed in the above reference article in the Journal of Applied Physics. Thecoils 15 and 16 are mounted on the body so as to be movable in a horizontal direction to the position shown by dotted lines. If it is desired to travel straight through the track, these coils remain in their inward position shown in solid lines and support of the vehicle results from the normal flux system obtained from the interaction between thecoils 13 and 14 and their associated reaction rails 5 and 6 and 9 and 10. However, if it is desired to switch to the upper branch track supported on the roadbed 2a, the coils l5 and 16 are extended to the position shown in dotted lines. In that case, the coils l5 and 16 which, like thecoils 13 and 14, are also preferably superconducting magnet coils will form with therespective reaction rail 7 and 8 and 11 and 12 a separate normal flux system. Since therails 7 and 8 and 11 and 12 are sloped upwardly, to the vertical branch track above the main track, the vehicle will be guided in that manner until it reaches the required level. The slope or radius of curvature of these rails is selected in accordance with the necessary requirements as to speed and so on. It will be recognized that in order to maintain high speed operation, the slope must be very gradual and thus will extend over a considerable distance.

Propulsion of the vehicle may be obtained through the use of a linear motor designated generally as 20, havingactive windings 21 and 22 mounted within the vehicle. In the embodiment illustrated on FIG. 1, thesewindings 21 and 22 are shown dashed since they are partially hidden by the magnet coils 26 and 27. Thewindings 21 and 22 are separated by apredetermined air gap 23. Protruding into theair gap 23 is areaction rail 24 extending vertically from theroadbed 2. Thereaction rail 24 is approximately centrally located between thereaction rail arrangements 3 and 4. This rail which can be made of aluminum for example, provides the armature of thelinear motor 20. As illustrated, between each winding 21 and 22 a gap ofdimension 25 will exist.

Thecoils 26 and 27 serve to maintain lateral guidance of the vehicle. Again, these will preferably be superconducting magnet coils and as shown are mounted on each side of therail 24. Therail 24 thus acts as an armature for the linear motor and at the same time can act as the reaction rail cooperating with thecoils 26 and 27 to maintain lateral guidance. In addition, the lateral guidance system can be controlled so as to properly maintain thegaps 25 between theexcitation windings 22 and 21 of thelinear motor 20 and thereaction rail 24. In addition to the lateral guidance forces obtained from thecoils 26 and 27 along withreaction rail 24, additional lateral guidance is obtained from the interaction of the superconducting coils 13 and 14 with the vertical reaction rails 6 and 10. Similarly, for switched operation, the superconducting coils l5 and 16 interact with thevertical rails 8 and 12 to aid in lateral guidance.

From viewing FIGS. 1 and 2, it is apparent that during a switched operation where the vehicle is being moved to the branch track of the upper roadway 2a, therail 24 will gradually come out of thegap 23 beween thewindings 21 and 22 and thus, the linear motor will steadily become less effective until at some point it has no effect at all. Considering this type of operation, the necessity of obtaining lateral guidance from the reaction rails 8 and 12 also becomes evident. The result of the loss of the cooperation between therail 24 and coils 21 and 22, is that the vehicle steadily loses speed within the switched area. That is, there is a gradual loss of propulsion power and at the same time an increase of braking forces. As' a result, the vehicle must enter the switch at a high enough speed so that it can reach the upper roadway 2a on which a reaction rail 24a is provided at which point propulsion will be resumed.

A further embodiment of the present invention is shown on FIG. 3. In this embodiment, avehicle 30 is suspended above aroadbed 2. Only the lower roadway is shown with the portions of the system extending to the upper road broken off. These would, of course, be extended to an upper roadway in the manner shown on FIG. 1. The vehicle again is provided with sets ofcoils 37 and 38 and 39 and 40 on each side which during normal operation can be used with an appropriate rail to form a zero flux system. For straight through travel in the switch area, thecoils 37 and 39 cooperate with reaction railsarrangements 31 and 32 in the manner described above in connection with FIG. 2. That is, the coil 37 cooperates with thehorizontal reaction rail 33 and thevertical reaction rail 35 and thecoil 39 with thehorizontal reaction rail 34 and thevertical reaction rail 36. As in the previously described embodiment, the coils 37 through 40 will preferably be superconducting magnet coils. However, in this embodiment, rather than mounting theupper coils 38 and 40 for horizontal motion when switching is desired, horizontally extendable and retractable reaction rails 43 and 44 are provided in the vehicle. Normally, they will be in the retracted position shown with the rail in dotted lines.

When extended, they will be in as in the cross sectional illustration with the portion of vehicle body supporting them being in the position shown in dotted lines. Along the roadbed on each side are provided a large number of controllable electromagnets designated 41 and 42. At the entrance to the switch, these lie in horizontal planes and will then follow a sloped path as indicated to the upper roadway. These electromagnets cooperate with the extended reaction rails 43 and 44 to guide the vehicle to the upper roadway. The reaction rails 43 and 44 which may be made of aluminum for example, will produce a lifting as well as a lateral stabilization force. Furthermore, this arrangement can be used for propulsion of the vehicle within the switched region. Such a suspension, guidance and propulsion system is described in Electrotechnische Zeitschrift edition B, vol. 23, No. l3, p. 3l l-3l3 (I971). Thus, the problem of the previous embodiment which required high speed entrance into the switch is eliminated in this embodiment.

If straight through travel is desired, the reaction rails 43 and 44 are retained in the retracted position and guidance of the vehicle through the switch is in the manner described above in connection with FIG. 1 with propulsion provided by thelinear propulsion motor 20. If it is desired to branch to the upper roadway, the reaction rails 43 and 44 are extended and the magnet coils 41 and 42 energized. As noted above, theelectromagnets 41 and 42 are installed along the desired slope or radius of curvature much in the manner described aboved in connection with the reaction rails of FIGS. 1 and 2. These magnets may be properly operated to provide, as noted above, suspension, guidance and propulsion within the switched area, thus causing the vehicle to be transported from the lower roadbed shown to an upper roadbed such as that illustrated on FIG. 1.

Although not shown on the figure, thevehicles 1 and 30 will typically be provided with conventional retractable wheels. These may be typical railroad wheels which can cooperate with conventional rails installed on the track or may be designed to roll directly on theroadbed 2.

As noted above, outside the switch area it is preferable that the vehicle be suspended and guided by a zero flux system which exhibits smaller losses than the normal flux system used within the switch. Because of this, a transition at the point where the switch is entered is necessary. That is, the vehicle must be gradually switched over from being guided by a zero flux system to being guided by a normal flux system as described above in connection with FIG. 1. Since the losses for a normal flux system can be up to ten times as large as the losses for a zero flux system, a large amount of adjustment is necessary and the transition cannot be allowed to occur suddenly. In order to achieve a gradual transitiomaluminum rails of the zero flux system having a cross section which decreases as the vehicle enters the normal flux system and leaves the zero flux system, i.e., when entering the switch, and through aluminum rails of the normal system having a cross section which correspondingly increases when entering the switch.

Although in each case, the reaction members on the roadbed have been disclosed as continuous conducting rails which, in accordance with the electrodynamic propulsion system being used, are non-magnetic, it will be recognized by those skilled in the art that these continuous rails can be placed by individual conductor loops used as reaction elements. When employing conductor loops, these loops are generally arranged in tandem at predetermined distances and are shortcircuited. In addition, it will be recognized that combinations of short-circuited conducting loops and continuous rails may also be used. These and other embodiments may be made without departing from the spirit of the invention which is intended to be limited solely by the appended claims.

What is claimed is:

1. In a suspension railroad system wherein vehicles are suspended using the electrodynamic repulsion principle, an improved switch for switching a vehicle from the main roadway lying in a first horizontal plane to a branch roadway lying in a horizontal plane vertically displaced from the first plane comprising:

a. a first electrodynamic suspension system including first means mounted in the vehicle and second means mounted on the main roadway cooperating with said first means;

b. a second electrodynamic suspension system comprising third means located on the roadway outwardly of said first means, and third means extending from said main roadway to the branch roadway in a different horizontal plane and fourth means in the vehicle for cooperating therewith, said fourth means being mechanically movable between a retractd position where they are clear of said third means on the roadway and an extended position where they are above said third means on the roadway to cooperate therewith.

2. A switch according toclaim 1 wherein said third means located on the roadway comprise reaction members located on each side of the roadway and wherein said fourth means in the vehicle comprise at least two magnet coils, one arranged on each side of the vehicle.

3. A switch according toclaim 2 wherein said third means on the roadbed comprise reaction rails which cooperate with said magnet coils to form a normal flux system.

4. A switch according toclaim 3 wherein said vehicle is suspended outside said switch area by zero flux system and further including a transition arrangement between said zero flux system and the normal flux system in said switch area.

5. A switch according toclaim 4 wherein the reaction members of the zero. flux system have a decreasing cross section in the direction of entry into the switch and an increasing cross section in the direction away from the switch.

6. A switch according toclaim 1 wherein said third means located on the roadway comprise magnet systems located on each side of said roadway and said fourth means in said vehicle comprise at least two reaction rails, one mounted on each side of said vehicle.

7. A switch according toclaim 6 wherein said reaction rails are made of non-magnetic electrically conducting material.

8. A switch according toclaim 6 wherein said fourth means on the roadway comprise electromagnets.

9. A switch according toclaim 8 wherein the system made up of said electromagnets on said roadbed and said reaction rails on said vehicle forms an electrodynamic lift and propulsion system for the vehicle.

10. A switch according toclaim 9 wherein said reaction rails and electromagnets form a normal flux system.

11. A switch according to claim 10 wherein said vehicle is suspended outside said switch area by zero flux system and further including a transition arrangement between said zero flux system and the normal flux system in said switch area.

12. A switch according to claim 11 wherein the reaction members of the zero flux system have a decreasing cross section in the direction of entry into the switch and an increasing cross section in the direction away from the switch.

13. A switch according toclaim 1 wherein the radius of curvature of said third means extending from said main to said branch roadway is a function of the desired maximum speed at which a vehicle will traverse the switch.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1 3 896 737 DATED Ju y 29, 1975 INVENTOMS) 3 Jiirgen Miericke It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Foreign Applicatoin Priority Data change date to May 2, 1973-- incolumn 1line 26, change "appraoches" to approaches-- incolumn 3,line 22, change "mchanically" to mechanically--line 27, change "reation" to -reaction incolumn 4,line 25, change "intereaction" to -interaction incolumn 6,line 31 change "aboved" to above incolumn 7,line 24, (claim 1) change "and third means" to said third means-- line 29, change "retractd" to --retracted Signed and Scaled this thirtieth Day of Deamber 1975 [SEAL] Arlen.

RUTH C. MASON C. IAISIIALL DANN Arresting Officer Commissioner of hmm and Trademarks

Claims (13)

1. In a suspension railroad system wherein vehicles are suspended using the electrodynamic repulsion principle, an improved switch for switching a vehicle from the main roadway lying in a first horizontal plane to a branch roadway lying in a horizontal plane vertically displaced from the first plane comprising: a. a first electrodynamic suspension system including first means mounted in the vehicle and second means mounted on the main roadway cooperating with said first means; b. a second electrodynamic suspension system comprising third means located on the roadway outwardly of said first means, and third means extending from said main roadway to the branch roadway in a different horizontal plane and fourth means in the vehicle for cooperating therewith, said fourth means being mechanically movable between a retractd position where they are clear of said third means on the roadway and an extended position where they are above said third means on the roadway to cooperate therewith.

2. A switch according to claim 1 wherein said third means located on the roadway comprise reaction members located on each side of the roadway and wherein said fourth means in the vehicle comprise at least two magnet coils, one arranged on each side of the vehicle.

3. A switch according to claim 2 wherein said third means on the roadbed comprise reaction rails which cooperate with said magnet coils to form a normal flux system.

4. A switch according to claim 3 wherein said vehicle is suspended outside said switch area by zero flux system and further including a transition arrangement between said zero flux system and the normal flux system in said switch area.

5. A switch according to claim 4 wherein the reaction members of the zero flux system have a decreasing cross section in the direction of entry into the switch and an increasing cross section in the direction away from the switch.

6. A switch according to claim 1 wherein said third means located on the roadway comprise magnet systems located on each side of said roadway and said fourth means in said vehicle comprise at least two reaction rails, one mounted on each side of said vehicle.

7. A switch according to claim 6 wherein said reaction rails are made of non-magnetic electrically conducting material.

8. A switch according to claim 6 wherein said fourth means on the roadway comprise electromagnets.

9. A switch according to claim 8 wherein the system made up of said electromagnets on said roadbed and said reaction rails on said vehicle forms an electrodynamic lift and propulsion system for the vehicle.

10. A switch according to claim 9 wherein said reaction rails and electromagnets form a normal flux system.

11. A switch according to claim 10 wherein said vehicle is suspended outside said switch area by zero flux system and further including a transition arrangement between said zero flux system and the normal flux system in said switch area.

12. A switch according to claim 11 wherein the reaction members of the zero flux system have a decreasing cross section in the direction of entry into the switch and an increasing cross section in the direction away from the switch.

13. A switch according to claim 1 wherein the radius of curvature of said third means extending from said main to said branch roadway is a function of the desired maximum speed at which a vehicle will traverse the switch.

Images