US 3774544 A
The invention relates to a switching system for a moving unit especially an air-cushion vehicle guided along a track, to have a selective connection between a main track and either of two branch tracks. The switching system comprises an assembly of two track sections. This assembly is mounted on an axis of rotation which is external to each branch track. By operating this assembly around this axis of rotation, one of the desired connections between the main track and the branch tracks can be obtained through one of the track sections.
Claims available in
Description (OCR text may contain errors)
United States Patent r191 Mouillon Nov. 27, 1973 SWITCHING SYSTEM FOR A MOVING 3,670,659 6/1972 Schurch 104/96 NI GUIDED ALONG A TRACK 3,308,766 3/ 1967 Urbinati 104/130  Inventor: Paul Mouillon, Lyon, France 7 Primary Examiner Gerald M Forlenza  Assignee: Maurice Barthalon, Verrieres-Lessistant ExarninerD. W. Keen B i (E fl France Attorney-1rvm S. Thompson et al.
 Filed: Mar; 10, 1972 ABSTRACT Appl. No.: 233,551
Foreign Application Priority Data Mar. 16, 1971 France 7109087 I References Cited UNITED STATES PATENTS 3/1970 Easton 104/23 FS 4/1967 Lauber 104/101 The invention relates to a switching system for a moving unit especially an air-cushion vehicle guided along a track, to have a selective connection between a main track and either of two branch tracks. The switching system comprises an assembly of two track sections. This assembly is mounted on an axis of rotation which is external to each branch track. By operating this assembly around this axis of rotation, one of the desired connections between the main track and the branch tracks can be obtained through one of the track sections.
4 Claims, 10 Drawing Figures Pmmimm 1975 3, 774,544
SHEET 30F 6 Fig.3
SWITCHING SYSTEM FOR A MOVING UNIT GUIDED ALONG A TRACK This invention relates to a switching system for a moving unit which is guided along a track, especially for a vehicle which is lifted by an air-cushion.
In known switching systems, use is made of a track section which is displaceable either in translational motion alone, or in a movement of translation associated with a movement of rotation about an axis at right angles to the plane of the tracks, or alternatively a rectilineal track section which is capable of rotational motion about an axis at right angles to the plane of the tracks. Apart from their substantial weight and high inertia, these systems involve time-consuming operations.
Switching systems for suspended vehicles of the wheeled type are also known which comprise a central switch constituted by a number of elements pivotally coupled to each other and track sections whichare also pivotally coupled so as to withdraw in certain positions of the switch. These systems are complicated, exhibit high inertia and entail a considerable number of operations, which has a detrimental efiect on their reliability and on the conditions of safety.
In the case of vehicles which are lifted by an aircushion and suspended from a track, it has been proposed either to construct a central switch capable of moving in rotation about a center of rotation located in the switch frog or to provide two retractable flanges in the lifting wall, one of the flanges being intended to complete the direct track whilst the other completes the diverging track. This type of switch is, however, relatively complex andcostly.
Mention will finally be made of a track-changing device which is intended for a transporter having a track in the shape of an inverted T, in which a main track can be connected selectively to either of two branch tracks disposed symmetrically with respect to the main track, by virtue of a movable element which is pivotally coupled to the main track and capable of rotating through an angle of 180 about an axis parallel to the axis of the main track. However, this device is limited to a symmetrical arrangement of the branch tracks.
The aim of the invention is to overcome the numerous disadvantages of known systems and to provide a switching system which is of simple constructional design, which is easy to operate and which can be employed for any non-symmetrical turnout.
A further aim of the invention is to provide a switching system which is particularly effective in the case of a vehicle which is lifted by an air-cushion.
In accordance with the invention, the switching sys-- tem for a moving unit guided along a track, especially for a vehicle lifted by an air-cushion, comprising an assembly of two track sections for selectively connecting a main track to either of two branch tracks, said assembly being rotatably mounted about an axis, is characterized in that the axis of rotation is external to each branch track.
This arrangement has the advantage of facilitating the mid-point of the extremity of the main track to the mid-points of the corresponding extremities of the branch tracks.
This arrangement makes it possible to simplify the operation of the system to an even greater extent and has the further advantage of enhancing the appearance of the structure.
In the event that the track extremities should not be located in the same horizontal plane, the axis of rotation is located in the plane bisecting the two planes which pass through said straight lines respectively and which are perpendicular to the mid-plane of the terminal portion of the main track.
According to a further characteristic feature, the track sections are relatively displaced through an angle which is substantially equal to the angle of rotation and, in the case of rotation through the track sections are disposed on each side of a plane which contains the axis of rotation.
Preferably, the track sections are carried by a frame which is movable about the axis of rotation and is coupled to a control unit placed between the branch tracks.
It is accordingly advantageous to ensure that the frame is rotatably mounted on the one hand with re spect to the main track and on the other hand with respect to the branch tracks by means of two aligned shafts, the second shaft being coupled to the control unit.
Further properties of the invention will become apparent from the following description, reference being made to the accompanying drawings which are given by way of non-limitative example, and in which FIG. 1 is a diagrammatic view in elevation, with portions broken away, showing a switching system for connecting the tracks of a transporter of the air-cushion vehicle type FIG. 2 is a top view of the switching system in the position of connection of the curved branch track FIG. 3 is a sectional view taken along line IlI-Ill of FIG. 2;
FIG. 4 is a sectional view taken along line IV-IV of FIG. 1, the switching system being in the position of connection of the straight branch track FIG. 5 is an end view of the switching system on the side nearest to the main track FIG. 6 is a sectional detail view taken along line VI-VI of FIG. 1
FIG. 7 is a partial longitudinal sectional view of the portions of the system which serve to rotate this latter switching system;
FIG. 9 is a diagrammatic end view of a switching system having an angle of rotation other than 180, this view being taken from the main track FIG. 10 is an end view of the switching system of FIG. 9 in the same position but looking from the branch tracks.
There is shown diagrammatically in FIG. I a suspended-car transporter of the type described in French Pat. No 1 474 851 of Jan. 19th, 1966 in the name of the present Applicant as well as a switching system for transferring the car or vehicle from the main track to either of the two branch tracks.
The track is formed by a substantially continuous beam which is illustrated diagrammatically a more detailed description of this beam may be found in the above-mentioned patent.
The main track 1 is assumed to be rectilineal in the terminal portion which is adjacent to the switch. One of the branch tracks 2 is located in the line of extension of the main track whilst the other branch track 3 has a certain degree of curvature. In this example, the branch tracks are located in the same horizontal plane and the track extremities to be connected are located in the same vertical plane (see FIG. 2).
The tracks are supported by means of lateral pillars or posts forming gantries 4, two of which are provided at the ends of the tracks to be connected on each side of the switch. The posts are relatively flexible in order that expansion stresses should be reduced to a minimum.
The switching system 5 comprises two track sections, namely a rectilineal section 6 corresponding to the branch track 2 and a curved section 7 corresponding to the branch track 3, said sections being rigidly fixed to a steel latticework frame 8, said frame being capable of rotational motion about an axis XX which is external to each of the branch tracks 2, 3.
The track sections 6,7 are rigidly fixed to the frame 8 by means of tie-rods 9 which permit positional adjustment of said track sections with respect to the tracks to be connected (see FIGS. 3 to 5).
In the example of construction under consideration, the two track sections 6, 7 are disposed at an angle of 180 with respect to each other on each side of a plane P which contains the axis of rotation XX (as shown in FIGS. 3 to 5) the angle of rotation is 180 and the axis of rotation XX coincides with the line bisecting the angle made by the straight lines D and D which joint the mid-point of the extremity of the main track 1 to the mid-points of the corresponding extremities of the branch tracks 2, 3 (as shown in FIG. 2). Moreover, the mid-points of the branch tracks 2, 3 are so designed as to be equidistant from the mid-point of the main track 1 so that the axis XX is at right angles to the plane of the extremities of the branch tracks.
The frame 8 is provided at each end with a crossmember 11, 12 (FIGS. 3 to 5) which is adjacent to the main track or to the branch tracks respectively and to which the track sections 6, 7 are attached in an adjustable manner by means of tie-rods l3.
Said cross-members 11, 12 respectively are rigidly fixed to two short aligned shafts or stub-shafts 14, 15 which define the axis of rotation XX of the track sections and one of which, namely the stub-shaft 15, is actuated in such manner as to cause the frame 8 to rotate through an angle of 180 between the two positions of connection. Adjustable stops 16 are provided on the beam 17 of each gantry 4 in order to arrest the crossmembers in the appropriate position at the end of rotational motion. Locking of the system while in service can be ensured by means of a locking-bolt (not shown).
The shafts 14, 15 are secured to the cross-members 11, 12 respectively and are each rotatably mounted in a spherical-bearing bushing 18, 19 which is fixed on the beam 17 of the corresponding gantry 4, the bushing 19 being disposed between the branch tracks.
The extremity of each track 1-3 is fitted with a retractable seal 21 which can be applied against a complementary bearing provided on each extremity of the corresponding track section 6, 7, at right angles to the axis of rotation XX.
FIG. 6 illustrates a seal 21 of this type, as constituted by an inflatable envelope partially embedded in a sealholder 22 which is removably secured to a flange 23 of the track. The envelope is connected by means of pipes 24 to a suitable source of fluid under pressure as will be explained in detail hereinafter. When in the inflated state, said envelope is applied against the complementary bearing surface 25 formed by a plate 26 which is attached to a flange 27 of the track section such as the section 6. Perfect continuity of the beam which serves as a track is thus ensured at the time of a connection. In the unconnected position, the clearance between a track section and the corresponding track extremity is at least equal to 2 mm so as to make allowance for free thermal expansion of these elements.
There are shown in FIG. 7 the stub-shafts 14, 15 which are hollow and each fitted with a spherical bearing 31 mounted in the corresponding bushing 18, 19 which is attached to the beam 17 by means of a bearing support 32, 33. The bearing support 33 is secured by means of a flanged connection to a hydraulic control motor 34 which is also carried by the beam 17. The shaft 35 of the motor 34 and the stub-shaft 15 are coupled together by means of a splined torsion shaft 36 which permits bending movements resulting from faulty alignment of the axis of rotation with respect to the axis of the drive shaft. This lack of coincidence may result from faulty construction or adjustment or from deformations arising from static, dynamic and thermal stresses in the movable frame and the gantries.
In the case of a moving unit which is displaced by electric power, it is evidently possible to associate with each track section a conductive element which ensures continuity of the electric power supply. Interruption of the supply can serve as a safety signal for preventing access to one of the tracks by the moving unit, which can thus no longer be guided.
In the case in which the moving unit is displaced by means of a linear electric motor, the secondary winding being connected to the track, the track sections are each fitted with a secondary-winding element without making it necessary to take any special precaution since the alignment of the motor is ensured by reason of the continuity of the tracks.
The hydraulic motor 34 can be replaced by a control unit comprising two hydraulic jacks, the operating rods of which are aligned and coupled together in such manner as to actuate a rotating mechanism which is coupled to the drive shaft 35.
This device, which will be described with reference to FIG. 8, serves to transfer the switching system from one position of connection to the other while ensuring positional control and operational safety.
The hydraulic control unit comprises a low-pressure hydraulic pump 41 which is supplied from a hydraulicfluid reservoir 42 and connected to an oleopneumatic accumulator 43 this latter supplies a three-way electro-valve 44 which is connected to the reservoir 42 by means of a discharge pipe 45. The electro-valve 44 has two solenoids 46, 47 which can be excited separately so that, in a neutral position corresponding to nonexcitation of the two solenoids, the hydraulic lowpressure is transmitted to two outlet pipes 48, 49 when the solenoid 46 is excited and the solenoid 47 is not excited, the pipe 48 is supplied whilst the pipe 49 is discharged, and conversely, when the solenoid 47 is excited and the solenoid 46 is not excited.
The pipes 48, 49 terminate respectively in two control push-rod elements 51, 52 which operate a threeposition valve 53, said valve being supplied by a highpressure hydraulic pump 54 which is connected to a reservoir 55. The valve 53 is connected to the reservoir 55 by means of a discharge pipe 56 and operates in the same manner as the electro-valve 44 under the control of the push-rod elements 51, 52 in order that the hydraulic-high-pressure may be transmitted either simultaneously or selectively to two outlet pipes 57, 58.
The pipes 57, 58 are each connected to a simple spring-loaded slide-valve 61, 62 which serves to put said pipes into communication with pipes 63, 64 respectively. Moreover, the pipes 57, 58 are each connected to a two-way slide-valve 65, 66' respectively, said slide-valve being associated with a locking device as will be explained hereinafter.
Each slide-valve 61, 62 is controlled by a hydraulic push-rod element 67, 68 and this latter is supplied by means of a pipe 71, 72 which can be put into communication with the pipe 48, 49 by means of the two-way valve 65, 66 when said valve is in the locking position.
The seals 21 which are associated with the branch tracks are supplied in parallel with the hydraulic pushrod elements 67, 68 whilst the seal 21 which is associated with the main track is supplied through either of the two pipes 71, 72 by means of a free slide-valve 73 which makes it possible to isolate one of the seals 21 and to supply the seal 21 in all cases.
The pipes 63, 64 which come from the valves 61, 62 are connected respectively to position detectors constituted by slide-valves 74, 75 which serve to detect the position of the switch at the end of travel. These slidevalves are capable of putting the pipes 63, into communication with high-pressure pipes 76, 77 respectively which terminate in cylinders 78, 79 of the springloaded piston type which constitute locking devices, the rods of which control the slide-valves 65, 66. The slide-valves 74, 75 make it possible in another position to establish a communication between the pipes 76, 77 by virtue of an intermediate pipe 80.
The two hydraulic actuating jacks 81, 82am connected to the slide-valves 65, 66 respectively by means of pipes 83, 84 which communicate with the pipes 57, 58 when these valves are in the unlocking position. Two pipes 85, 86 serve to establish a circulation of fluid from the jacks 81, 82 to the pipes 77, 76 respectively, and only in this direction, by means of non-retum valves 87, 88.
The operation of this hydraulic control unit will be explained in the case of changeover of the switching system from the position of connection of the curved branch track 3 to the position of connection of the straight branch track 2.
Initially, the branch track 3 being connected to the main track 1, the jack 82 is located at the end of travel with its operating rod in the outwardly extended positions, and the jack 81 is located at the end of travel with its rod in the inwardly withdrawn position. The seal 21 of the branch track 3 and the seal 21 of the main track 1 are in the inflated state the position detector 74 is actuated by the switching system and the slide-valve 65 is in the locked position by virtue of the action of the restoring spring of the locking cylinder 78.
The self-excitation circuit of the solenoid 36 of the electro-valve 44 is energized, with the result that the pipe 48 is put into communication with the discharge pipe 45. In consequence, the pressure drops within the pipe 71, the seal 21 associated with the branch track 3, the seal 21' associated with the main track 1 and the hydraulic push-rod element 67. The valve 61 is then returned by its spring to the position in which a connec tion is established between the pipes 57 and 63.
The control push-rod element 52 associated with the valve 53 is put under pressure by reason of the fact that t the pipe 49 is supplied whilst the control push-rod element 51 is discharged. The valve 53 then supplies the pipe 57 and the pipe 58 is discharged. In consequence, the jack 82 is relieved by means of the pipes and 58 and by means of the slide-valve 66 which is in the unlocking position. At the same time, the pipes 57, 63 and 76 are put under pressure and the slide-valve 65 is unlocked under the action of the rod of the cylinder 78. The valve 65 establishes a connection between the pipes 83 and 57, with the result that the jack 81 is supplied. The switching system is therefore moved to the position of connection of the branch track 2.
The position detector 74 then puts the pipes 76 and 77 into communication by means of the intermediate pipe 80, thereby ensuring positional maintenance of the locking devices 78 and 79. At the end of travel, the detector puts the pipes 64 and 77 into communication, with the result that the locking device 79 is discharged. The jack 81, which is connected through the pipe 86 to the pipe 77, is also relieved. The slide-valve 66 is actuated when the rod of the cylinder 79 is returned by its spring so as to establish a connection between the pipes 49 and 72. The seal 21 associated with the branch track 2 and the seal 21' associated with the main track 1 are inflated and the hydraulic push-rod element is supplied.
An end-of-travel contact (not shown) interrupts the excitation of the solenoid 46, thus permitting the return of the electro-valve 44 and the valve 53 to the neutral position. The switching system takes up the position of connection of the branch track 2. It will be noted that the angle of rotation can be of any desired value although an angle of 180 has been given by way of example in the figures referred-to above.
W6. 9 shows diagrammatically the moving portion of a switch designed for a rotation through an angle a other than 180, the axis of rotation X-X being located at the end and it is' noted in comparison with the switch designed for rotation through 180 that the axis of rotation is located at a distance from the track sections 90 and 91.
FIG. 16 shows diagrammatically the moving portion of the same switch with the extremities 92 and 93 of the traclc sections 90 and 91 at the end nearest to the branch tracks.
The branch track 94 would be in register with the extremity 92 after rotationof the track sections through an angle a in the direction of the arrow. By means of a chain-dotted line which has a slightly embracing form for the sake of enhanced clarity, there can also be seen the branch track 95 which is in register with the extremity 93 of the connected track section.
It is apparent from FIG. 10 that one of the branch tracks is at a different height with respect to the other track at the level of connection of the moving portion of the switch and that one of the track sections (or both sections) has a variable angle of tilt along the switch.
The switching system which has just been described has many advantages by reason of its simplicity of construction, its small overall size, the speed with which it can be operated and its outstanding reliability. Moreover, in the case of air-cushion vehicles, the inflatable seals ensure a very high standard of leak-tightness in the retracted state, any contact is eliminated, thereby reducing friction solely to that of the bearings and permitting substantial variations in play arising from manufacturing tolerances and from the action of thermal expansion stresses.
The spherical bearings ensure accurate maintenance of the distance imposed by the movable sections and serve to lighten or even to dispense with thrust bearings. However, a design solution involving the use of conventional joumal-bearings and thrust-bearings remains applicable and can constitute an alternative form of construction.
Furthermore, the control unit 34 can also consist of an electric reduction gear motor.
What I claim is:
l. A switching system for a moving unit guided along a track, especially for a vehicle supported by an air cushion, comprising an assembly of two track sections for selectively connecting a main track to either of two branch tracks, said assembly being rotatably mounted about an axis of rotation which is external to each branch track, wherein each track or track section extremity is fitted with a retractable seal which is capable of cooperating with a bearing surface formed on the corresponding track or track section extremity.
2. A system according to claim 1, wherein, in the case of an air-cushion transporter, the seal is constituted by an inflatable envelope which ensures leak-tightness between the track section and the connected track.
3. A system according to claim 1, wherein the seals associated with the branch tracks are disposed in the same plane at right angles to the axis of rotation.
4. A switching system for a moving unit guided along a track, especially for a vehicle supported by an air cushion, comprising an assembly of two track sections for selectively connecting a main track to either of two branch tracks, said track sections being carried by a frame which is movable about an axis of rotation external to each branch track and is coupled to a control unit placed between the branch tracks, said control unit comprising two jacks associated with means for converting a linear movement into a rotational movement.