EP1459954A1

EP1459954A1 - Railway points actuating system

Info

Publication number: EP1459954A1
Application number: EP03360040A
Authority: EP
Inventors: Kurt Vogelgsang; Kuno Henn; Thomas Ludmann
Original assignee: Alcatel CIT SA; Alcatel SA
Current assignee: Alcatel Lucent SAS
Priority date: 2003-03-21
Filing date: 2003-03-21
Publication date: 2004-09-22
Anticipated expiration: 2023-03-21
Also published as: DE60306102D1; DE60306102T2; EP1459954B1; ATE329811T1

Abstract

A railway points actuating system comprises at several locations along the railway points adjusting modules (6, 7) each comprising at least one hydraulic adjusting cylinder and means for adjusting the travel of an adjusting rod (21, 22), wherein the hydraulic adjusting cylinders have the same volume and diameter. Thus, the number of different parts needed in a railway points actuating system can be reduced.

Description

Background of the invention

The invention relates to a railway points actuation system.
Railway points generally comprise several adjusting modules, which may comprise locks along their length. The locks hold the switch tongues in place. The adjusting modules are normally associated with a point drive. Upon receiving a signal, the locks open and the distant tongue is moved a first distance, then both tongues are moved together a second distance until the distant tongue touches a stock rail with its free end. After that the second tongue is moved and the tongues are locked in place by the lock. For railway points with a large radius, several adjusting modules and point drives are usually used since a movement of the free ends of the tongues would not be sufficient to move the entire tongues into the correct place. Hence, the greater the radius, the more adjusting modules are required. Due to the individual railway points geometry, different displacements of the tongues need to be realized at each adjusting module. This implies a great number of different components, not only for different railway points but also for the different adjusting modules. For example, it has been suggested to adjust the distance by which a tongue is moved by using different hydraulic cylinders, each suitable to move the tongues a specific distance. Obviously, for each adjusting module a different cylinder is required.
A further requirement for railway points is that they can be installed quickly so that traffic is only interrupted for a short period of time and that in the region of the railway points machine-driven temping of the sleepers is possible.

Object of the invention

It is the object of the invention to provide a railway points actuating system which requires few components and which is easy to install.

Short description of the invention

This object is achieved by a railway points actuating system comprising at several locations along the railway points adjusting modules, each comprising at least one hydraulic adjusting cylinder and means for adjusting the travel of an adjusting rod, wherein the hydraulic adjusting cylinders have the same volume and diameter. This has the advantage that in contrast to the state of the art the same adjusting modules with the same components can be used. An adjusting module can be used at different locations of the railway points. Only one type of hydraulic adjusting cylinder is needed for the whole system, which reduces the number of different parts which have to be fabricated or bought for the assembly of a railway points actuating system. This is particularly advantageous for railway points with a large radius, since a large number of adjusting modules is required in such railway points, each module having to adjust the switch tongues by a different distance. Furthermore, the hydraulic adjusting cylinders of the adjusting modules can be hydraulically coupled. Thus, only one point drive, located, p. ex. at the free end of the switch tongues, is needed for activating all cylinders of the adjusting modules. Hydraulic coupling is more reliable than mechanical coupling of the adjusting modules and is maintenance-free. In each adjusting module one hydraulic adjusting cylinder may be sufficient, if the hydraulic cylinder is divided into two chambers by a piston. Alternatively, two hydraulic adjusting cylinders coupled by a piston rod may be provided.
In a particularly preferred embodiment the means for adjusting the travel of an adjusting rod is a rotatable member arranged between the hydraulic adjusting cylinder and the adjusting rod, wherein the articulating point between the rotatable member and the adjusting rod is adjustable with respect to the rotational axis of the rotatable member. Thus, by adjusting the location of the articulation point the travel of the adjusting rod can be adjusted for a given adjusting cylinder. Hence, the adjusting module comprising a hydraulic adjusting cylinder connected to the adjusting rod via the rotatable member can be used at different locations along the railway points. When an adjusting module is to be used at a different location along the railway points or if the adjusting module is to be installed for the first time, all that needs to be done is to adjust the travel of the adjustment rod by changing the position of the articulation point. Advantageously, the rotatable member is a disc, which is connected to the hydraulic adjusting cylinder with its free end.
In the case of the railway points being trailable at least one additional cylinder may be provided in one adjusting module, which additional cylinder is connected to the associated adjusting rod. One additional cylinder is sufficient, if the cylinder comprises two chambers. If cylinders with one hydraulic chamber are to be used, two hydraulic cylinders coupled by a piston rod are needed. The volume and diameter of the chambers of the additional cylinder or of the additional single-chambered cylinders may have the same volume and dimensions as the adjusting cylinders. To ensure proper switching of the tongues, however, a slightly larger volume is preferred. The adjusting rod may be held in place by a retaining system. The additional cylinder is connected to the hydraulic cylinders in the adjusting modules along the railway points. When the railway points are split by an approaching train, a force is exerted upon the adjusting cylinders of the adjusting modules and thus also on the additional cylinder. If the force becomes too strong the retaining system opens and the adjusting rod is allowed into another position. This results in the tongues changing position. Provision of the retaining system has the advantage that the tongues only change position if the railway points are really split by a train. Smaller external forces cannot cause the railway points to switch. If a train approaches from the correct direction the tongues are firmly held in place by the retaining system and the adjusting rod and possibly by locks.
In a preferred embodiment of the invention at least some of the hydraulic cylinders are connected in series. This allows synchronous and reliable movement of the tongues. In the case of non-trailable tongues, all the hydraulic adjusting cylinders max be connected in series. In the case of trailable tongues the hydraulic adjusting cylinders of the adjusting module comprising the additional cylinder may be mechanically coupled to the additional cylinder and the additional cylinder may be connected in series to the hydraulic adjusting cylinders of the remaining adjusting modules.
Advantageously, an adjusting module comprises at least two two-way valves. The two-way valves ensure synchronous and complete movement of the adjusting rods in the adjusting modules. The two-way valves are provided in the hydraulic circuit connecting the hydraulic cylinders of the different adjusting modules. In the case of non-trailable railway points, one hydraulic adjusting cylinder per adjusting module may be sufficient. Each chamber of the hydraulic cylinder may be connected to a two-way valve. Preferably, the two-way valves are controlled by the means for adjusting the travel of the adjusting rod, in particular by the position of the rotatable member.
It is particularly advantageous if the railway points actuating system is pre-installed. New railway points can be quickly installed if all the components, in particular the adjusting modules, are pre-installed in the factory. Thus, the time a track cannot be used due to the installation of railway points can be greatly reduced. Preferably, such a pre-installed railway points actuation system comprises a standardized four wire interface so it can be easily connected to an already existing interlocking system.
The safety of railway points can be increased if point detection means are provided. Once the position of the tongues has been altered the point detection means check whether the correct and intended position has been reached. Preferably, the point detection means comprise facing stretcher detector bars in association with detector contacts which are connected to the signal box. All the adjusting modules may comprise facing point detector bars.
In a preferred further development at least one point detection means is located between two neighbouring adjusting modules provided along the points. This improves safety of the railway points because the position of the tongues in between the adjusting modules is also monitored. For example, the tongues can be in the correct position at each adjusting module, but in between two neighbouring adjusting modules an obstacle like a stone may cause a bend in a tongue. Such a bend should be detected to prevent trains from derailing. The point detection means may be pre-installed and may be connected to a point drive.
Locating the adjusting modules in hollow sleepers allows pre-installation of the adjusting modules and easy transport together with the complete railway points actuating system.
It is particularly advantageous if all components of the system are located in between the rails. Thus, the system can be arranged in a space-saving manner. Furthermore, if no components are located outside the rails, packing of the sleepers can be performed more effectively in the region of the railway points. In particular, machine-driven packing is possible.
Further advantages can be extracted from the description and the enclosed drawing. The features mentioned above and below can be used in accordance with the invention either individually or collectively in any combination. The embodiments mentioned are not to be understood as exhaustive enumeration but rather have exemplary character for the description of the invention.

Drawings

The invention is shown in the drawing.

Fig. 1: shows a railway track with railway points;
Fig. 2: shows a railway points actuation system for non-trailable points; and
Fig. 3: shows a railway points actuation system for trailable points.

Fig. 1 shows part of a railway track 1 with stock rails 2 provided on sleepers 3. Switch tongues 4, 5 are located between the stock rails 2. At several locations along the switch tongues 4, 5 are provided adjusting modules 6, 7 located on hollow sleepers 8, 9. Locks 10 - 13 and locking bars 14, 15 are provided at each adjusting module 6, 7 for locking the switch tongues into position when the switch tongues are not moved. Each adjusting module 6, 7 is provided with an adjusting rod 21, 22 connected to the locking bars 14, 15. Obviously, at each location of the adjusting modules 6, 7 the switch tongues 4, 5 have to travel a different distance if the railway points are moved. In order to monitor that the switch tongues 4, 5 have traveled the correct distance upon actuation of the railway points, point detection means with facing point detector bars 16, 17 are provided at each adjusting module 6, 7. Furthermore, point detection means 18 are provided between two neighboring adjusting modules 6, 7, where the point detection means 18 comprises facing point lock stretchers 19. The adjusting modules 6, 7 are hydraulically connected. Hydraulic fluid is supplied by a pump unit 20 which, in the embodiment, does not form part of the railway points actuating system per se and which may therefore be located next to the rails 2. However, the components of the railway points actuating system, including the point detection means 18 are located between the stock rails 2. This ensures a compact arrangement of the components. The pump unit 20 may, however, also be integrated with one of the adjusting modules 6, 7 and thus be located between the rails 2 and form part of the railway points actuation system.
Fig. 2 shows a railway points actuating system 30 provided with three adjusting modules 31 - 33, where adjusting module 31 is located at the free ends of the switch tongues of the railway points. Each adjusting module comprises an adjusting rod 34 - 36 for adjusting the position of the switch tongues (not shown) connected to the adjusting rods 34 - 36. The adjusting rods 34 - 36 are connected at an articulation point 37 - 39 to means 40 - 42 for adjusting the travel of the adjusting rods 34 - 36. The means 40 - 42 are rotatable about a rotational axis 43 - 45. The free ends of the means 40 - 42 are connected to a piston rod 46 - 48, which communicates with a first and a second hydraulic cylinder 49 - 54. The position of the articulation point 37 - 39 can be adjusted with respect to the rotational axis 43 - 45. Thus, the travel of the adjusting rod 34 - 36 can be easily adjusted, depending on the location of the adjusting module 31 - 33 along the railway points. For moving the adjusting rods 34 - 36 to the left, hydraulic fluid is pumped by the pump 55, which is driven by a motor 56, into the first hydraulic adjusting cylinder 49. This causes the piston rod 46 to move to the right and the adjusting rod 34 to move to the left. At the same time hydraulic fluid is pushed out of the second hydraulic adjusting cylinder 50 and into the first hydraulic adjusting cylinder 51 of the second adjusting module 32, causing piston rod 47 to move to the right and the adjusting rod 35 to move to the left. The hydraulic fluid pushed out of the second hydraulic adjusting cylinder 52 because of the movement of piston rod 47 to the right goes into the first hydraulic adjusting cylinder 53 of the third adjusting module 33, thus displacing piston rod 48. The hydraulic fluid escaping from the second hydraulic adjusting cylinder 54 travels back to the pump 55, and, if there is a surplus, into the fluid reservoir 57 via the pressure control valve 58. If the volume of the hydraulic fluid increases due to an increase in temperature, hydraulic fluid can escape into the reservoir 57 via pressure control valve 58. On the other hand, if the volume of the hydraulic fluid decreases because of a decrease in temperature, additional hydraulic fluid can be drawn from the reservoir 57 via check valves 58a, 58b. The hydraulic adjusting cylinders 49 - 54 are connected in series. The hydraulic adjusting cylinders 49 - 54 act as hydraulic pumps for subsequent hydraulic cylinders. In each adjusting module 31 - 33 there are also provided two-way valves 59 - 64. To start with, the two-way valve 59 is in an open position when the piston rod 46 is in the position shown in Fig. 2. However, hydraulic fluid is prevented from directly flowing to the second adjusting module 32 by check valve 65. As soon as the piston rod 46 starts moving to the right, the two-way valve 59 closes, preventing hydraulic fluid to flow back from the second hydraulic cylinder 50 towards the pump 55. Two-way valve 60 is closed. The check valves 66, 67 prevent hydraulic fluid passing in both directions. As soon as the piston rod 46 reaches its end position, the two-way valve 60 opens, thus allowing hydraulic fluid to be pumped via check valve 66 into the first hydraulic cylinder 51 of adjusting module 32. This ensures the piston rod 47 reaching its end position. The two-way valves 61 - 64 in adjusting modules 32, 33 operate in the same manner. All hydraulic adjusting cylinders 49 - 54 have the same volume and diameter. In the pump unit 68 is provided a further two-way valve 69 which closes the hydraulic circuit if the tongues are not being moved, and hence acts as pressure compensation valve. The pump unit 68 constitutes the point drive. It may be integrated with one of the adjusting modules 31 - 33 or kept as a separate unit. Preferably, the pump unit 68 is kept between the rails, however, if the hydraulic connections to the first adjusting module 31 can be arranged such as to not obstruct packing of the sleepers, it may also be disposed next to the rails. Movement of the adjusting rods 34 - 36 is effected in an analogous way.
Whereas Fig. 2 shows a point actuating system for non-trailable railway points, Fig. 3 shows a point actuating system 70 for trailable railway points. The only difference lies in the adjusting module 71. In addition to the first and second hydraulic adjusting cylinders 72, 73, an additional cylinder 74 is provided, which is also connected to the adjusting rod 75. If hydraulic fluid is pumped into the first adjusting cylinder 72, the adjusting rod 75 is moved to the left as described in Fig. 2 for the adjusting cylinders 49, 50 and adjusting rod 34. Since the adjusting rod 75 is mechanically coupled to the piston 76 of the additional cylinder 74, the piston 76 is moved to the right, thus pressing hydraulic fluid out of the second chamber 77 and into the first adjusting cylinder 78. If the pressure of the hydraulic fluid pressed out of the second chamber 77 becomes too large, the hydraulic fluid gets into reservoir 80 via pressure control valve 81. If a train first gets onto the railway points at the location of the adjusting module 82, i.e. the train traveling from top to bottom in the drawing, a force is exerted onto the switch tongues and thus onto the adjusting rod 83. If, for example such a force is exerted that the adjusting rod 83 is forced to the left, piston rod 84 is forced to the right, thereby pressing hydraulic fluid out of the second adjusting cylinder 85 and into the first chamber 86 of the additional cylinder 74. At first, a movement of piston 76 to the right is prevented because of the piston 76 being mechanically coupled to adjusting rod 75, which is kept in position by the means 87 and the adjusting cylinders 72, 73. However, the adjusting rod 75 is coupled to the member 87 by means of a retaining system 88. Hence, if the pressure by piston 76 becomes too large, the retaining system 88 opens, allowing the adjusting rod 75 and thus the free ends of the switch tongues to move. Thus, derailing of the approaching train is avoided. The volume of the chambers 77, 86 of the additional cylinder 74 may have the same or a slightly larger volume and the same diameter as the adjusting cylinders 72, 73, 78, 85. Since the additional cylinder 74 acts as hydraulic pump for the subsequent cylinders 78, 85, which are connected in series, a slightly larger volume ensures the adjusting rods in the subsequent adjusting modules to reach their end positions. In the first adjusting module 71 are further provided check valves 89, 90, which allow hydraulic fluid to be drawn from the reservoir 80, 91 if the volume of the hydraulic fluid decreases.

Claims

Railway points actuating system (30; 70) comprising at several locations along the railway points adjusting modules (6, 7; 31 - 33; 71, 82) each comprising at least one hydraulic adjusting cylinder (49 - 54; 72, 73, 78, 85) and means (40 - 42, 87) for adjusting the travel of an adjusting rod (21, 22; 46 - 48; 84), wherein the hydraulic adjusting cylinders (49 - 54; 72, 73, 78, 85) have the same volume and diameter.
System according to claim 1, characterized in that the means (40 - 42, 87) for adjusting the travel of an adjusting rod (21, 22; 46 - 48; 84) is a rotatable member arranged between the hydraulic adjusting cylinder (49 - 54; 72, 73, 78, 85) and the adjusting rod (21, 22; 46 - 48; 84), wherein the articulating point (37 - 39) between the rotatable member and the adjusting rod (21, 22; 46 - 48; 84) is adjustable with respect to the rotational axis (43 - 45) of the rotatable member.
System according to claim 1, characterized in that in the case of the railway points being trailable at least one additional cylinder (74) is provided in one adjusting module (71), which additional cylinder (74) is connected to the associated adjusting rod (75).
System according to claim 1, characterized in that at least some of the hydraulic cylinders (49 - 54; 74, 78, 85) are connected in series.
System according to claim1, characterized in that an adjusting module (6, 7; 31 - 33; 71, 82) comprises at least two two-way valves (59 - 64).
System according to claim 1, characterized in that the railway points actuating system (30; 70) is pre-installed.
System according to claim 1, characterized in that point detection means (18) are provided.
System according to claim 7, characterized in that at least one point detection means (18) is located between two neighbouring adjusting modules (6, 7) provided along the railway points.
System according to claim 1, characterized in that the adjusting modules (6, 7; 31 - 33; 71, 82) are located in hollow sleepers (8, 9).
System according to claim 1, characterized in that all components of the system are located in between the rails (2).