Switch drive for a railway track

Abstract

Switch drive (3) for a railway track (1) with a housing (4) in which the following are stored: an electrically operated drive motor (5), an actuating force limiting clutch (6), a gearbox (7, 7.1, 7.2), a connecting rod (8) mounted perpendicular to the railway track, which is connected to the switch points (2) of the railway track (1), and by which the switch points (2) can be moved, a locking device (9) for fixing the end positions of the actuating rod (8) and switch tongues (2) in their end positions, wherein the drive motor (5) is connected to the actuating rod (8) via the actuating force limiting clutch (6) and the gearbox (7, 7.1, 7.2) for its movement into one of the end positions characterized by the fact that The drive motor (5), actuating force limiting clutch (6) and gearbox (7, 7.1, 7.2) are mounted on a support frame (10) which can be stored independently of the actuating rod (8) in the housing (4) and can be removed without removing the actuating rod (8).

Description

[0001] The invention relates to a switch drive for a railway track according to the preamble of claim 1. This switch drive is known from DE 10 2011 016 259 A1. It is a switch drive intended for passenger railway tracks and is characterized by a long service life and high reliability, even under demanding operating conditions. These requirements necessitate structural features of the switch drive which, due to its size and technical complexity, make it unsuitable for railway systems with a limited service life and not intended for high-speed passenger traffic. Such track and switch systems are particularly common in large construction sites, such as tunnel construction. In such operations, unforeseen and irregular events must also be expected.

[0002] Patent application DE 32 27 203 A1 discloses a switch-changing device with locking mechanism. The device essentially consists of a frame box equipped with a lockable cover, a mechanical part for switching and locking the switch linkage, a hydraulic part for controlling the movements of the mechanical part, and an electrical part for driving the hydraulic elements and for monitoring the position and locking. These various parts are housed in or supported by the frame box.

[0003] Patent application EP 2 192 020 A1 discloses a device for moving railway switches with at least two hydraulic actuators, a unit for supplying hydraulic fluid to the hydraulic actuators, which are driven by control means and actuate / deactivate the supply unit. The actuators are each operationally connected to switches at a different location, so that when the supply unit is actuated, hydraulic fluid is supplied to the actuators, thereby moving the switches between their initial and final positions. Means for synchronizing the stroke of the two actuators are provided, the synchronization means consisting of a unit that sets the amount of fluid per unit of time for each actuator. The setting is achieved by specifying a predetermined volume of fluid per unit of time, which is supplied to each actuator by each setting unit.

[0004] The object of the invention is to design a switch drive in such a way that it can be easily removed and replaced without disruption or interruption of the plant operation.

[0005] The solution follows from claim 1.

[0006] This solution is characterized by the fact that the drive components, which are not used in setting the switch, can be removed and replaced without interrupting railway operations.

[0007] The turnout drive shown has the advantage that such a high actuating force can be exerted on the connecting rod against track 1 that the secure engagement of the switch blade with the track is guaranteed. On the other hand, this actuating force can drop to zero as soon as the end position is reached, since the end position is positively locked by the locking device and its fixed housing in the drive unit, and no additional contact force is required for the secure engagement of the switch blade with the intended track. All parts belonging to the drive, in particular • the drive motor / alternatively a hydraulic cylinder, • a gearbox, • a clutch for limiting the actuating force, • Possibly also the gearbox for moving the actuating rod / coupling rod, which is connected to the switch tongues, is housed on a support frame, which is independent of the actuating rod and the drive housing and can be inserted into or removed from it.

[0008] In the further development according to claim 2, it is ensured that the switch remains functional even when the support frame and drive are removed, since the end position locking mechanism remains in blocking contact with the actuating rod even when the support frame is removed, thanks to the blocking device permanently attached in the housing.

[0009] The switch drive's gearbox can interact with the actuating rod by means of a rack and a dead-end coupling attached to it. Claim 3 specifies an alternative embodiment in which the rack and the dead-end coupling are mounted directly in the housing and remain in the housing when the support frame is removed.

[0010] In contrast, the switch drive according to claim 4 has the advantage that the gearbox, the rack, and the dead-stroke coupling attached to it are directly mounted in the support structure and, when the support frame is installed in the housing, are operatively connected to the actuating rod, and when the support frame is removed, are disengaged from the actuating rod. Thus, all parts of the switch drive that do not serve to fix the end positions of the switch blades can be removed from the housing and are therefore easy to replace, maintain, or repair. Claim 5 relates to a coupling by which the actuating rod can be connected to the drive on the one hand and to the locking device on the other, but which also allows for the simple installation and removal of the drive without any assembly effort.

[0011] A particularly advantageous embodiment of the invention, which enables the installation and removal of the drive, but also allows the locking of the switch tongues with the drive removed and without applying a positioning force, is the subject of claim 6.

[0012] The further development of the invention according to claim 7 is – regardless of the other aspects of the design – generally suitable for turnouts with end-position locking that must not be driven into the intended track without prior adjustment. This further development prevents undefined, extensive damage from occurring when driving into the turnout without prior adjustment.

[0013] The further development of the invention according to claim 8 serves the safety of the operating personnel in the event of a failure of the switch and the necessity of manual operation.

[0014] The invention will be described below with reference to the drawing. The drawing shows: Fig. 1 a switch in overhead view Fig. 2 the switch drive with a view into the housing Fig. 2A a detail of Fig. 2

[0015] Fig. Figure 1 shows a switch in plan view. The switch blades 2 can be alternately engaged with the left or right rail 1 by the switch drive 3 – as shown in Fig. 1 - to be brought.

[0016] In this design, which is particularly suitable for confined spaces, the switch drive is located between the two switch blades. The actuating rod 8 of the switch drive 3 is connected to both switch blades. The switch drive 3 is housed in a drive unit 4. The closed state is shown. Therefore, the individual components of the switch drive, namely the drive motor 5, gear train 7.1, actuating force limiting clutch 6 and gear train 7.2, as well as the locking device 9, are only indicated. These components will be described in more detail below. Fig. 2 described.

[0017] Fig. Figure 2 shows the opened drive housing 4. The cover is not visible here because the housing is cut in a horizontal plane in the axis of the actuating rod 8.

[0018] The adjusting rod 8 has eyelets 8.1 and 8.2 at its ends, with which the adjusting rod is attached to the in Fig. 2 switch tongues (not shown). A blocking block 12 in the form of a cube is pushed onto the actuating rod 8 and secured by a blocking pin 13, which positively penetrates the blocking block 12 and the actuating rod 8 and is fixed at its ends - for example - by nuts.

[0019] The locking block 12 is fixed in the right or left end position of the switch in the switch housing 4 by the locking device 9. For this purpose, the locking device 9 is mounted in the housing. Two locking tongues 9.1 and 9.2 are slidably mounted radially in the direction of the actuating rod 8 within the locking device 9 and are pressed radially towards the actuating rod 8 by springs (not shown).

[0020] In Fig. 1 and Fig. Figure 2 shows that the right switch blade is in contact with the right rail 1. This end position is secured by the fact that the left locking blade 9.1 engages the locking block 12 on the left side, so that the actuating rod 8 with the locking block 12 attached to it is fixed in the right end position.

[0021] To move the switch to the other end position, the left locking tongue 9.1 must be disengaged from the locking block 12.

[0022] This is done through backdrop plate 14, which is in Fig. 2A in detail, in Fig. Figure 2 is shown only with a dashed line because it lies in the same plane as the cam rollers 9.3 and 9.4, both above the drawing plane and above the visible surface of the blocking block 12. These are rotatably mounted on the blocking tongues 9.1 and 9.2, respectively (more on this later). In the secondary figure 2A, the cam plate is shown in plan view as a detail.

[0023] The cam plate 14 is attached to a dead-end coupling 15. The dead-end coupling 15 is movable on a sliding rod 16 parallel to the actuating rod 8. The dead-end coupling engages the locking block 12 with its U-shaped, projecting gripping jaws 15.1 and 15.2. The distance between these gripping jaws (the clear width between them) is greater than the width of the locking block 12. Therefore, the locking block 12 is only engaged by the gripping jaws after a dead-end travel of the dead-end coupling.

[0024] In contrast, the cam plate 14 follows every movement in the dead-end coupling. The cam plate 14 has two inclined cam tracks 14.1 and 14.2 facing the two eyelets 8.1 and 8.2, which lie in the same plane as the locking rollers 9.1 and 9.2 and interact with them.

[0025] More precisely: backdrop plate 14 is a rectangular plate. It is equipped with its - in Fig. 2 - lower corners attached to the dead-end coupling 15 and lies sliding on or close to the blocking block 12. The two side flanks of the cam plate located in the direction of the eyelets 8.1 and 8.2 merge with the cam tracks 14.1 and 14.2 into the upper guide edge 14.3, which is aligned parallel to the actuating rod 8.

[0026] By adjusting the dead-end coupling 15 to the left, the cam plate 14 is also moved to the left. This causes the locking roller 9.3 to roll along the cam track 14.1 and lift the locking tongue 9.1, i.e., away from the actuating rod 8. This movement continues until the locking roller 9.3 reaches the upper guide edge 14.3 of the cam plate 14. Together, the two locking rollers 9.1 and 9.2 now roll over the locking block 12 on the upper guide edge 14.3 of the cam plate 14 until, with a corresponding shift of the dead-end coupling 15, the right coupling shoe 15.2 reaches the right side of the locking block 12. The dimensions are such that at this moment the locking roller 9.4 also reaches the cam track 14.2 and slides along it towards the actuating rod 8 until the locking tongue 9.2. The locking block 12 engages on the right side precisely at the moment and in the position when the connecting rod 8, and with it the corresponding switch blade, has reached the left end position of the switch. The switch is now fixed in this end position by the locking blade 9.2.

[0027] It follows from the foregoing that the end-position safety device is part of the housing 4 and remains functional as long as the housing 4 remains in its installation location. This is primarily due to the fact that the actuating rod 8 and the locking device 9 are fixedly and independently installed in the housing 4, separate from the drive.

[0028] The support device 10 serves to hold the parts used for the drive. It is designed so that it can be installed in and removed from the housing 4 with just a few simple steps.

[0029] In the support structure 10 are • the electric drive motor 5 • Gear train 7.1, consisting of two gears and the worm 7.3 • Actuating force limiting clutch 6 is mounted. However, it should be emphasized that the sliding rod 16 with the dead-stroke clutch 15 and the cam plate 14 can also be mounted in the support device 10. They can then be removed from engagement with the locking block 12 without any further assembly equipment and, together with all other drive components, removed from the housing 4 for maintenance, repair, or replacement, as described.

[0030] The drive motor 5 is connected to the actuating force limiting clutch 6 via the gear train 7.1, consisting of the two gears and the worm 7.3. For drive by the worm 7.3, the drive gear 6.1 of the clutch 6 is provided with a toothed ring. The coaxial output gear 6.2 is frictionally connected to the drive gear 6.1, i.e., as a friction wheel pair. Therefore, only a limited torque can be transmitted via this connection between gears 6.1 and 6.2. This limits the actuating force that can be exerted on the actuating rod 8.

[0031] The output gear 6.2 engages with the rack 11 via the gear connection of the transmission train 7.2, which is part of the dead-stroke coupling 15.

[0032] The drive motor 5 can be driven in both directions. This moves the dead-end coupling 15 in the left or right direction, as described above.

[0033] The electric motor 5 is designed to exert a very high actuating force and contact force on the track 1 via the connecting rod 8, ensuring that the switch blade can be moved to the track even over obstacles. However, it sometimes happens that the path of the switch blades 2 is blocked by stones, debris, or other objects. In such cases, there is a risk of damaging the switch drive. The design and adjustment of the actuating force limiting clutch 6 ensures that, on the one hand, sufficient actuating force can be applied to move the switch blades 2 into their end positions, but on the other hand, that the actuating force limiting clutch 6 slips, thus preventing further damage, if the path of the switch blades is blocked by rocks or similar objects.

[0034] The previously described switch drive is not suitable for "butt-running." Nevertheless, it occurs, particularly on railways operating during construction, that the switch is "butt-running," even though this is expressly prohibited with the described switch design. "Butt-running" means that the switch is traversed from one of the intersecting tracks 1, which would not be traversed in the opposite direction if the switch were in its set end position. This "butt-running" causes the switch blade, which is in contact with the rail, to be forcibly lifted from the rail by the wheel flange of the train and pushed out of its end position. This leads to damage and destruction of the switch drive and the switch itself, especially the locking device 9, and possibly also to the derailment of the passing train.

[0035] To prevent and limit this damage, the locking pin 13, which connects the locking block 12 to the adjusting rod 8, is designed as a predetermined breaking point. Its dimensions, and any incorporated predetermined breaking points, limit its shear or bending load capacity. This allows the damage to be easily repaired by inserting a new locking pin.

[0036] It is also possible that the electric motor 5 may fail, either due to an interruption of the power supply or due to damage. A manual drive is provided for this eventuality. For this purpose, the shaft 19 of the worm gear 7.3 has a coupling 20 on one end, which corresponds to a coupling 20 of a hand crank 21. If the motor 5 fails, the cover 22 can be removed from the switch housing 4, in particular, unscrewed. The shaft of the hand crank 21 can then be inserted into a hole that communicates with the shaft 19 of the worm gear 7.3. The coupling 20 connects the two shafts. In this case, there would be a risk that if the electric motor 5 were to start unexpectedly, the hand crank 21 would rotate very quickly and thereby injure the operator.

[0037] To prevent this, a switch 24 is installed in the power supply line 23. This switch is actuated by a contact pin 25 and is configured so that the motor 5's circuit can be interrupted regardless of the operating state. This contact pin is parallel to the shaft 19, i.e., the direction of screwing the cover 22. Screwing on the cover 22 closes the contact 24, thus re-opening the circuit to the drive motor 5. However, if the cover 22 is unscrewed for manual operation of the point motor, the contact pin 25 will move to the left under spring force. The safety contact 24 opens the circuit. The drive motor 5 can then no longer be started. Reference sign 1. Railway track, switch 2. Switch tongue 3. Switch drive 4. Housing 5. Electrically operated drive motor 6. Actuating force limiting clutch 6.1 Drive wheel 6.2 Output gear 7. Gearbox 7.1 Gearbox train 7.2 Gearbox train 7.3 Snail 8. Adjusting rod 8 8.1 Eyelet 8.2. Eyelet 9. Locking device, device for determining the end position of the tie rod and switch blades in their end positions 9.1 Blocked tongue 9.2 Blocked tongue 9.3 Backstage roles Blocking role 9.4 Backstage roles, blocking role 10. Support frame, support device 11. Rack and pinion 12. Blocking block 13. Blocking pen 14. Backdrop plate 14.1 Scenery Railway 14.2 Scenery Railway 14.3 Leading edge 15. Dead-end coupling 15.1 Clutch shoe Gripping jaws 15.2 Clutch shoe Gripping jaws 16. Sliding rod 19th wave 20. Coupling device, coupling pair 21. Hand crank 22. Lid 23. Power supply 24. Switch, contact, safety contact 25. Contact pin

Claims

[1] Switch drive (3) for a railway track (1) with a housing (4) in which the following are stored: an electrically operated drive motor (5), an actuating force limiting clutch (6), a gearbox (7, 7.1, 7.2), a connecting rod (8) mounted perpendicular to the railway track, which is connected to the switch points (2) of the railway track (1), and by which the switch points (2) can be moved, a locking device (9) for fixing the end positions of the actuating rod (8) and switch tongues (2) in their end positions, wherein the drive motor (5) is connected to the actuating rod (8) via the actuating force limiting clutch (6) and the gearbox (7, 7.1, 7.2) for its movement into one of the end positions characterized by , that The drive motor (5), actuating force limiting clutch (6) and gearbox (7, 7.1, 7.2) are mounted on a support frame (10) which can be stored independently of the actuating rod (8) in the housing (4) and can be removed without removing the actuating rod (8). [2] Switch drive (3) according to claim 1 characterized by , that the locking device (9) is permanently attached in the housing (4) and remains permanently connected to the housing (4) and in operative connection with the actuating rod (8) when the support frame (10) is removed. [3] Switch drive (3) according to claim 1 characterized by , that the gearbox (7, 7.1, 7.2) interacts with the actuating rod (8) by means of a rack (11) and a dead-stroke coupling (15) attached to it, and that the rack (11) and the dead-stroke coupling (15) are directly mounted in the housing (4) and remain in the housing (4) when the support frame (10) is removed. [4] Switch drive (3) according to claim 1 characterized by , that the gearbox (7, 7.1, 7.2) interacts with the actuating rod (8) by means of a rack (11) and a dead-stroke coupling (15) attached to it, that the rack (11) and the dead-stroke coupling (15) are directly supported in the support frame (10) and that the dead-stroke coupling (15) is installed in the support frame (10) the housing (4) is to be brought into operative connection with the actuating rod (8) and, when the support frame (10) is removed, out of engagement with the actuating rod (8). [5] Switch drive (3) according to claim 1 characterized by , that a locking block (12) is attached to the actuating rod (8), that the dead-stroke coupling (15) is movable parallel to the actuating rod (8) by means of the rack (11), wherein the dead-stroke coupling (15) engages the locking block (12) on both sides on two engagement surfaces with a coupling shoe (15.1, 15.2) each, and wherein the clear width between the coupling shoes (15.1, 15.2) is greater than the distance between the engagement surfaces. [6] Switch drive (3) according to claim 1 characterized by , that the locking device (9) comprises two locking tongues (9.1, 9.2) which are pressed radially against the actuating rod (8) by force transmitters, such that the locking tongues (9.1, 9.2) slide with sliding elements (9.3, 9.4) on a cam track (14.1, 14.2) which is rigidly connected to the dead-stroke coupling (15), and that the cam track (14.1, 14.2), the distance between the blocking tongues (9.1, 9.2) and the distance between the attack surfaces are dimensioned such that in each end position of the actuating rod (8) one of the blocking tongues (9.1, 9.2) engages the blocking block (12) at one of its attack surfaces and secures it in the end position. [7] Switch drive (3) according to claim 1 characterized by , that the blocking block (12) is attached to the actuating rod (8) by means of a blocking pin (13) penetrating both, which is dimensioned as a predetermined breaking point in case of violent movement of the switch tongue (2). [8] Switch drive (3) according to claim 1 characterized by , that a shaft (19) driven by the drive motor (5) can be connected to a hand crank (21), the shaft of which can be coupled to the shaft through a hole in the housing (4), the hole being closable by a cover (22), preferably a screw cover, that a safety contact (24) is connected to the circuit of the drive motor (5), which is closed by placing the cover (22) on and opens automatically when the cover (22) is removed, in particular under spring force.

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