Switch drive for the switch of a railway track

Abstract

Switch drive (3) for the switch (1) of a railway track, which is connected to switch blades (2) of the switch (1) for displacement into one of the end positions by means of an actuating rod (8) mounted axially displaceable perpendicular to the railway track, which can be positively locked in each of the end positions by means of a stationary blocking device (9). characterized by the fact that a locking block (12) is slidably mounted on the adjusting rod (8), but can be fixed via a drive coupling (13), that the locking block (12) is, on the one hand, for displacing the actuating rod (8) into one of its end positions via a gearbox (7.1,7.2) with an electrically operated drive motor (5) and, on the other hand, for axially fixing the actuating rod (8) in each of the end positions, can be positively connected to the stationary locking device (9), that the drive coupling (13) consists of two friction-fit locking pairs, • which locking pairs are located opposite each other on a guide track perpendicular to the axis of the adjusting rod (8), offset by 180° diametrically on both sides of the adjusting rod (8), • and each of which has a detent notch (13.5 or 13.6) provided on the circumference of the adjusting rod (8) and a detent element (13.1 or 13.2) which is movably mounted in the blocking block (12) perpendicular to the surface of the adjusting rod (8) and is pressed by spring force (pressure spring (13.12 or 13.13)) in the direction towards the surface of the adjusting rod (8) or detent notch (13.5 or 13.6) and interacts with the detent notch (13.5 or 13.6).

Description

[0001] The invention relates to a switch drive for the switch of a railway track according to the preamble of claim 1.

[0002] This point drive is known from DE 10 2011 016 259 A1.

[0003] German patent application DE 19 52 824 A discloses a device for switching points in which the points are fixed in their end positions via the connecting rods and coupling means are arranged between the drive devices and the connecting rods of the points. An electro-hydraulic drive for switching points is proposed in which a pressure relief valve is arranged between the pump unit and the control valves to set a permissible actuating force, and the hydraulic fluid supply circuit between the pump unit and the actuating cylinders is interrupted after the point end positions have been reached to set permissible holding and approach forces.

[0004] Patent AT 400 239 B discloses a drive-over switch drive. A coupling device is arranged between a drive unit and the push rod, which, in the coupled state, has a retaining roller that engages in a recess in the push rod with spring tension. In order to implement such a coupling device even in confined spaces, two counter rollers are provided, arranged essentially symmetrically with respect to the direction of movement of the retaining roller. These counter rollers are mounted essentially perpendicular to the direction of movement of the retaining roller and are biased by at least one retaining spring in the direction of contact with the retaining roller.

[0005] Regardless of their specific design, such switches are generally equipped with an end-position locking mechanism. This prevents the leading switch blade from failing to engage the approach track due to contamination or from lifting away from the approach track due to vibrations or similar factors. Such end-position locking can be achieved by positive locking, for example, by a movable latch of a stationary locking device engaging a detent surface perpendicular to the length of the connecting rod when the end position is reached. This detent surface acts as a positive-locking latch, either directly on the connecting rod or on a locking block, which in turn is firmly coupled to the connecting rod by means of a positive-locking coupling element.Such a turnout cannot be driven into the intended route without prior adjustment without severely damaging the turnout or its drive mechanism and / or causing the overrunning wagon to derail. Damage can be limited, but not entirely avoided, even if the coupling element is designed as a weak point with a predetermined breaking point. Therefore, turnouts used in shunting operations, factory traffic, and construction site traffic are preferably equipped with a friction-fit end-position locking mechanism.

[0006] For this purpose, the actuating rod can be slidably mounted on / in the locking block and fixed by a force-locking coupling element in such a way that, when a defined thrust force on the actuating rod is exceeded, the coupling element releases and the actuating rod can be slidably displaced in the locking block, while the locking block is held in a fixed position by the pawl of the stationary locking device as a positive locking latch.

[0007] Such a friction-fit coupling element is formed in particular by a detent notch in a generatrix or a lateral surface of the adjusting rod with two wedge-shaped intersecting or partially cylindrical flanks and a detent roller which engages in the detent notch by applying high continuous forces, preferably spring forces.

[0008] Here, the locking roller is rotatably mounted in a guide carriage, which is guided on the locking block perpendicular to the actuating rod and supported on the locking block by spring force in a direction perpendicular to the actuating rod. The minimum thrust force required to press the actuating rod into the end positions of the switch blades and hold it there can and must be predetermined by the spring forces and the inclination of the flanks of the locking notch in the direction of movement, i.e., along the generatrix or surface of the actuating rod.

[0009] However, it has been found that the release force at which this coupling element disengages and the connecting rod becomes movable within the block when the switch is traversed is difficult to predict and is in any case significantly higher than the minimum thrust force required to hold the connecting rod in its end positions. For safety reasons, no compromise can be made when determining this minimum thrust force. Therefore, the release forces are currently too high for switch blades held by friction, and considerable damage during dead-end traversal is unavoidable.

[0010] The object of the invention is to equip the switch drive of a switch that can be traversed without prior adjustment into the intended track in such a way that the release force of the tie rod relative to its fixed holding point (referred to in this application as a blocking device) is predetermined and only exceeds the minimum thrust required to hold the tie rod in its end positions by a predetermined amount. This improved design prevents undefined damage from occurring during traversal. The switch drive is also suitable for passenger railway tracks and is characterized by a long service life and high reliability, even under demanding operating conditions.

[0011] The solution follows from claim 1.

[0012] This solution is characterized by the fact that the release force of the connecting rod relative to its fixed position is calculable and reproducible, and only exceeds the minimum thrust force required to hold the connecting rod in its end positions by a definable amount. Therefore, without exceeding release forces that could cause damage during dead-end contact, the minimum thrust force can be chosen to be high enough to ensure the end position and secure engagement of the switch blade with the intended track. To hold the connecting rod and the switch blade in their end positions, this actuating force can drop to zero, since the end position is secured by the positive engagement between the locking block of the connecting rod and the locking device located in the drive housing. A significant advantage of the invention is that the influence of frictional forces on the release force can be eliminated or reduced to a minimal level.The further development of the switch drive according to claims 2 and 3 serves to improve the bearing and design of the locking elements in this respect.

[0013] The further development of the switch drive according to claim 4, 5, or 6 enables the detection of the unplanned process of the switch running over the block and allows for the manual or automatic implementation of suitable countermeasures to resume normal operation of the switch system, or to initiate safety checks or repairs. Reliable detection is ensured by measuring the running over based on two movements. These two movements can be measured absolutely, i.e., in relation to the drive housing of the switch drive, or—preferably and more simply—relative to the blocking block, or—preferably and even more simply—relative to each other.

[0014] The further development of the switch drive according to claim 7 provides that a continuous signal is given by the position monitoring device (26). This allows the dead-end collision to be detected, even if the switch drive was subsequently operated, with or without success.

[0015] The further development of the switch drive according to claim 8 provides for the use of the position monitoring device (26) for detecting the point-to-point movement. This device can also be used independently of the invention according to the preceding claims, provided that the position monitoring device operates non-destructively and is suitable for outputting a signal, preferably an electrical signal. The point-to-point movement and the release of the connecting rod from the locking block in an end position generate a control signal for the electrical actuation of the drive motor (5) such that the locking block is released from its current end position by the stationary locking device, and the connecting rod (8) follows the movement until the coupling re-engages. It is now possible to move the switch blades manually or automatically back into an end position when the switch is reported as clear again by wagon detection devices.Either the movement of the drive and the locking block can continue until the actuating rod (8) reaches the other end position, or—conversely—the movement of the drive and the locking block can be reversed until the actuating rod (8) reaches the end position from which it was displaced by the dead-end run. This transforms the irregular dead-end run into a regular control operation and returns the turnout to normal operation.

[0016] The further development of the switch drive according to claim 9 serves to connect the tie rod to the switch drive. By coupling the switch drive with the actuation (engaging and releasing) of the locking device via a dead-end coupling (15), it is ensured that the two processes cannot be initiated with overlap. This guarantees that the switch remains functional even with the support frame and drive removed, since the tie rod and its end-position locking mechanism remain in a blocking connection with the tie rod due to the locking device permanently attached to the housing, even when the support frame is removed. 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.

[0017] The further development of the switch drive according to claim 10 provides an advantageous possibility for driving the latching pawls (referred to in this application as blocking tongues (9.1, 9.2) with which the actuating rod is positively locked relative to the stationary blocking device (9).

[0018] Two locking tongues (9.1, 9.2) are movably mounted on the locking device and pressed radially against the actuating rod (8) by force transmitters. They are actuated by the operation of the switch drive itself, whereby the distance of the

[0019] The locking tongues and the distance between their contact surfaces on the locking block are dimensioned such that, in each end position of the adjusting rod (8), one of the locking tongues engages the locking block (12) at one of its contact surfaces and secures it in the end position. This makes it possible to reduce the thrust force acting on the adjusting rod to zero in the end positions.

[0020] These designs have the advantage that all parts belonging to the drive, in particular • the drive motor / alternatively a hydraulic cylinder, • a gearbox, • possibly also a clutch to limit the actuating force, • the gearbox for moving the actuating rod / coupling rod, which is connected to the switch tongues, is housed on a support frame and can be removed from and inserted into the drive housing independently of the actuating rod and its end position locking mechanism.

[0021] 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 Fig. 3, Fig. 3A, Fig. 3B Details of the mounting of the locking block 12 on the adjusting rod 8. The same reference numerals are used below for functionally identical parts.

[0022] The description applies to all figures unless specific features of a particular figure are noted.

[0023] 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.

[0024] 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.

[0025] Therefore, the individual components of the switch drive, namely drive motor 5, gear train 7.1, actuating force limiting coupling 6 and gear train 7.2, as well as the blocking device 9, are only indicated. These parts will be described in more detail below. Fig. 2 to described.

[0026] 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.

[0027] 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. The two switch tongues (not shown) are attached. A blocking block 12 in the form of a cube is slid onto the actuating rod 8. The blocking block 12 is therefore slidably mounted on the actuating rod 8. It is held in place in the middle section of the actuating rod 8, or vice versa, by a frictional coupling 13, which is designed as a snap-fit ​​pair. Further details on this will follow later with reference to the Fig. 3.

[0028] 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).

[0029] 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 locking block 12 with the actuating rod 8, which is positively locked in the right end position, is positively locked.

[0030] To move the switch to the other end position, the left locking tongue 9.1 must be disengaged from the locking block 12.

[0031] 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.

[0032] 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.

[0033] In contrast, the cam plate 14 follows every movement in the dead-end coupling. The cam plate 14 – facing the two eyelets 8.1 and 8.2 respectively – has two inclined cam tracks 14.1 and 14.2, which lie in the same plane as the locking rollers 9.1 and 9.2 and interact with them.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] In the support structure 10 are 1. the electric drive motor 5 2. Gear train 7.1, consisting of two gears and the worm 7.3 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.

[0039] 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 equipped 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.

[0040] Due to the special design of the connection between the actuating rod 8 and the locking block 12 - see below for further details - the actuating force that can be exerted on the actuating rod 8 is also limited, so that under certain circumstances and preferably the actuating force limiting clutch 6 can be dispensed with.

[0041] 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.

[0042] 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.

[0043] 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, enabling the individual switch blade to be moved to the guide 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 coupling 6 and / or the configuration of the connection between the connecting rod 8 and the locking block 12 – see below – ensures that, on the one hand, sufficient actuating force can be applied to move the switch blades 2 into their end positions, while on the other hand, the actuating force limiting coupling 6 slips, thus preventing further damage, if the path of the switch blades is blocked by rocks or similar objects.

[0044] Since, according to this invention, the force required to release the actuating rod 8 from its connection with the locking block can be precisely and reproducibly predetermined, the difference to the minimum force required to press the switch blades – as described above and further below – can be small. Therefore, on the one hand, the minimum force required to press the switch blades can be increased to the level necessary for safety reasons by appropriately designing the locking pairs 13, and on the other hand, the force required to release the actuating rod 8 from its connection with the locking block can be limited to the permissible level to prevent damage.

[0045] Although undesirable, it sometimes happens, especially on railways operating under construction conditions, that the switch is "driven in the butt position".

[0046] A "butt hit" occurs when a train approaches a switch from one of the intersecting tracks (track 1) that would not be traversed in the opposite direction if the switch were in its set end position. This "butt hit" causes the switch blade, which is in contact with the rail, to be forcibly lifted from the guide rail by the train's wheel flange and pushed out of its end position. This leads to damage and destruction of the switch mechanism and the switch itself, or to the derailment of the passing train.

[0047] According to the invention, the force / thrust / release force required to release the actuating rod 8 from its connection with the locking block is limited. This force-fit connection of the actuating rod 8 with the locking block is described below.

[0048] The Fig. 3, Fig. 3A, Fig. Figure 3B shows details of the mounting of the blocking block 12 on the adjusting rod 8.

[0049] In Fig. 3 and Fig. 3A have the same view direction as Fig. 2, wherein in the Fig. 2 the backdrop plate 14 (dashed) in the foreground as well as the top of the block block 12 everything except the roller shafts 13.7 or 13.8 is covered. Fig. 3 and Fig. Figure 3B shows the blocking block 12 in sections rotated 90° to each other. For clarification, the locking rollers 13.1 and 13.2, as well as the roller shafts 13.7 and 13.8, are shown.

[0050] Fig. Figure 3A shows the central region e of the adjusting rod 8. Detent notches 13.5 and 13.6 are recessed into the central region. The detent notches extend onto generatrix or lateral surfaces 13.10, 13.11 of the adjusting rod 8, which are diametrically opposed by 180°. Each of the detent notches can be represented as a penetration of a cylindrical surface by the preferably cylindrical surface of the adjusting rod 8. However, each of the detent notches can also be a semicircular cylindrical recess extending along the respective generatrix / lateral surface and having a sufficient width for the respective detent roller 13.1 or 13.2. At their intersection, the respective generatrix / lateral surface forms an obtuse angle with the tangent to the detent notch 13.5 or 13.6 such that the respective detent roller 13.1, 13.112. The object can roll more or less gently into the recess of the detent notch or roll out again after overcoming a predetermined resistance force. The detent notches can also be formed by straight flanks meeting at an obtuse angle in a V-shape.

[0051] The locking block 12 passes through a bearing opening that is adapted to the circumference of the adjusting rod and in which the adjusting rod 8 is slidably mounted. The adjusting rod 8, and consequently also the bearing opening, can have a rectangular, square, or circular cross-section.

[0052] Block 12 is provided with a recess 27.1, 27.2 on opposite sides. These recesses intersect the bearing opening on opposite sides. A roller shaft 13.7 or 13.8 with a locking roller 13.1 or 13.2 is mounted in each of these recesses, wherein either the roller shaft is rigidly connected to the locking roller and the roller shaft is rotatably mounted, or the roller shaft is not rotatable and the locking roller is rotatably mounted on it. For this purpose, the side walls of the block 12 have a guide slot 28 in which the ends of the roller shafts 13.7, 13.8 are slidably guided.

[0053] The recesses 27.1 and 27.2 are closed by a cover 29. In each recess, two guide slides 13.3 and 13.4, respectively, are guided in a straight line on two guide pins 30 parallel to each other and to the axis of the adjusting rod 8. Between the guide pins 30, each guide slide has a partially circular, cylindrical bearing recess, which is adapted to the surface of the roller shafts 13.7 and 13.8 and serves to support or rotatably mount (so) the roller shafts. The guide slides are loaded on both sides and symmetrically to the adjusting rod by compression springs 31 such that the guide slides and the roller shafts 13.7 and 13.8, which cross the adjusting rod perpendicularly, are pressed towards the adjusting rod 8. Therefore, the detent rollers 13.1 and 13.2 are constantly under a bearing force in their respective detent notches 13.5 and 13.6. The adjusting rod can only be moved axially by overcoming these support forces.The springs 31, when installed, all have the same compressive force and are selected, dimensioned, and clamped in such a way that they exert a defined compressive force which, taking into account the geometric design of the locking notches 13.5 and 13.6 and any unavoidable frictional forces, leads to a predetermined release force required to release the frictional connection between the locking block 12 and the stationary locking device 9, and which must be withstood without damage during the point-to-point approach until the connecting rod is released from the point drive.

[0054] This release force is set higher than the minimum thrust force that the switch drive must exert on the switch tongue against the guide track via the blocking block 12 and the actuating rod 8 in order to ensure that the end position is reached and held safely.

[0055] The invention ensures that the release force and the minimum thrust force can be set and predetermined not only accurately and reproducibly, but also with minimal difference.

[0056] If the release force is overcome, the actuating rod 8 can be axially displaced relative to the fixed blocking block 12, the locking rollers 13.5 and 13.6 roll on the generatrix / spherical surfaces 13.10 and 13.11 facing them, and the switch tongue releases from the guide track.

[0057] The invention ensures that only predetermined forces act in the axial direction of the actuating rod. Because the locking rollers 13.1 and 13.2 bear against the actuating rod from diametrically opposite sides with equal pressure from the clamping springs 31, the locking rollers act as bearings and eliminate the influence of significant frictional forces on both sides of the actuating rod 8, both in the locked position of the actuating rod (i.e., with regard to the release force) and when the actuating rod is moving within the locking block. Therefore, if the switch has been operated in the butt open position, the switch can easily be manually returned to the intended position and the actuating rod to the locked position.

[0058] Whether the switch was operated in the butt open position can easily be determined by a position monitoring device / detector that detects the position of the locking shafts relative to the blocking block or - as shown - relative to each other.

[0059] In the simplest case, a detector that detects the relative position of the locking shafts consists—as shown here—of an inelastic plastic strip 26.1 with a predetermined breaking point 26.2, the ends of which are slipped over the ends of the roller shafts 13.7 and 13.8 above the cam plate 14—see Fig. 2. When the connecting rod is released from the locking block 12 and the locking rollers move out of their locking notches, the center distance of the roller shafts increases, and the plastic strip tears at the predetermined breaking point. Since the plastic strip is a signal color and clearly visible from the outside, a continuous signal is present, indicating the unplanned process of the switch being driven into position at any time. The connecting rod can then be manually operated by the switch drive using the hand roller 21, so that the connecting rod 8 returns to its intended position in the locking block 12, the locking rollers engage in their locking notches, and then either the other switch blade moves to the opposite guide track or the switch returns to its initial position. This version is simple, space-saving, and effective.

[0060] For turnouts that are traversed at high frequency, an electrical detector 26.3 (in Fig. 3B opposite the cam plate 14, attached to the blocking block), which uses sensing pins 26.4 to scan the radial relative position of the locking shafts. Its electrical output signal, which signals the stub-up movement, can then be sent to the control unit 32 of the switch drive to – possibly with a time delay or when the switch is clear – a wheel counter pair 33 with input wheel counter 33.1 and output wheel counter 33.2 ( Fig. 1)- to automatically actuate the drive so that the actuating rod 8 reaches its target position in the blocking block 12 and the locking rollers engage in their locking notches and then either the other of the switch blades comes to the other guide track or the switch is returned to its initial position.

[0061] For manual operation of the switch drive—as described above or in the event of a failure of the electric motor 5—a manual drive is provided by means of a hand crank 21. 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 the hand crank 21. The cover 22 can be removed from the switch housing 4, in particular by unscrewing it. 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 two shafts are connected to each other by means of the coupling 20. 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 cause injury to the operator.

[0062] 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. an electrically operated drive motor 6. a force-limiting clutch 6.1 Drive wheel 6.2 Output gear 7. a gearbox 7.1 Gearbox train 7.2 Gearbox train 7.3 Snail 8. Adjusting rod 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 12. Blocking block 13. the coupling, locking pairs 13.1. Locking roller 13.2. Locking roller 13.3. Guide sled 13.4. Guide sled 13.5. Rast notch 13.6. Rast notch 13.7. Roller axles, roller shafts 13.8. Roller axles Roller shafts 13.9. Guide path 13.10. Generatrix 13.11. Generatrix 13.12. Pressure spring 13.13. Pressure spring 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 26. Situation monitoring device 26.1 Plastic band 26.2 Breaking Point 26.3 electrical detector 26.4 Stylus 27 Exclusion 28 guide slots 29 lids 30 guide pins 31 pressure springs 32. Control unit 33 Wheel counter pairing 33.1 Input wheel counter 33.2 Output wheel counter

Claims

[1] Switch drive (3) for the switch (1) of a railway track, which is connected to switch blades (2) of the switch (1) for displacement into one of the end positions by means of an actuating rod (8) mounted axially displaceable perpendicular to the railway track, which can be positively locked in each of the end positions by means of a stationary locking device (9). characterized by , that a locking block (12) is slidably mounted on the adjusting rod (8), but can be fixed via a drive coupling (13), that the locking block (12) is, on the one hand, for displacing the actuating rod (8) into one of its end positions via a gearbox (7.1,7.2) with an electrically operated drive motor (5) and, on the other hand, for axially fixing the actuating rod (8) in each of the end positions, can be positively connected to the stationary locking device (9), that the drive coupling (13) consists of two friction-fit locking pairs, • which locking pairs are located opposite each other on a guide track perpendicular to the axis of the adjusting rod (8), offset by 180° diametrically on both sides of the adjusting rod (8), • and each of which has a detent notch (13.5 or 13.6) provided on the circumference of the adjusting rod (8) and a detent element (13.1 or 13.2) which is movably mounted in the blocking block (12) perpendicular to the surface of the adjusting rod (8) and is pressed by spring force (pressure spring (13.12 or 13.13)) in the direction towards the surface of the adjusting rod (8) or detent notch (13.5 or 13.6) and interacts with the detent notch (13.5 or 13.6). [2] Switch drive (3) according to claim 1 characterized by , that the locking element (13.1 or 13.2) is mounted in a guide slide (13.3 or 13.4) on which the spring force of pressure springs (13.12 or 13.13) acts in the direction towards the surface of the adjusting rod (8). [3] Switch drive (3) according to claim 2 characterized by, that the detent element (13.1 or 13.2) is a preferably cylindrical detent roller rolling on the surface of the adjusting rod (8), the roller shaft (13.7 or 13.8) of which is mounted in the guide slide (13.3 or 13.4) perpendicular to its path of movement and with roller axes (13.7, 13.8) perpendicularly intersecting the axis of the adjusting rod (8), so that by movement of the two guide slides (13.3, 13.4) on the locking block (12) the roller axes (13.7, 13.8) of the detent rollers (13.1, 13.2) are movable parallel to themselves and the detent rollers (13.1, 13.2) in the relative target position of the locking block (12) to the adjusting rod (8) in the respective detent notch (13.5 or 13.6) of the adjusting rod lying on the surface of the rod. (8) snap into place under spring pressure (pressure spring (13.12, 13.13)) simultaneously. [4] Switch drive (3) according to claim 1 characterized by, that the position of the locking elements (13.1 or 13.2) relative to each other or relative to the blocking block (12) is measured by a position monitoring device (26). [5] Switch drive (3) according to claim 2 characterized by , that the position of the guide slides (13.3 or 13.4) relative to each other or relative to the blocking block (12) is measured by a position monitoring device (26). [6] Switch drive (3) according to claim 3 characterized by , that the position of the roller shafts (13.7 or 13.8) relative to each other or relative to the locking block (12) is measured by a position monitoring device (26). [7] Switch drive (3) according to one of claims 4 to 6, characterized by , that the position monitoring device (26) indicates as a continuous signal that the locking elements (13.1, 13.2) have left their intended position in the locking notches (13.5, 13.6). [8] Switch drive (3) according to one of claims 4 to 6, characterized by, that the position monitoring device (26) indicates, by the position of the guide slides (13.3, 13.4) or roller shafts (13.7, 13.8) or locking rollers (13.1, 13.2) relative to each other or relative to the locking block (12), that the locking rollers (13.1, 13.2) have left their nominal position in the locking notches (13.5, 13.6). a control signal for the electrical actuation of the drive motor (5) is given in such a way that the actuating rod (8) with the detent notches (13.5, 13.6) follows the movement of the detent rollers (13.1, 13.2) from their current end position until the detent rollers (13.1, 13.2) engage in the detent notches (13.5, 13.6), preferably the movement of the actuating rod (8) is continued until the other end position is reached. [9] Switch drive (3) according to claim 1 characterized by, that the transmission (7.1,7.2) interacts with the actuating rod (8) by means of a rack (11) and a dead-stroke coupling (15) attached thereto, such 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 each with a coupling shoe (15.1, 15.2) and wherein the clear width between the coupling shoes (15.1, 15.2) is greater than the distance between the engagement surfaces. [10] 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.

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