AU2006251241A1 - Drive system for a rail switch - Google Patents

Abstract

Disclosed is a drive unit comprising a positioning rod (2) which is connected to the switch blades and is movable between two final positions by means of a drive unit (1), e.g. a cylinder-piston arrangement. A mechanical lock (3) is provided that is effective in the final positions of the positioning rod (2). In order to obtain a great degree of safety, the mechanical lock (3) acts directly upon the positioning rod (2) while a catch (4) that is equipped with a separately controllable cylinder-piston arrangement (6) is supplied for said lock (3). The catch (4) blocks a movement of the lock in the direction of the unlocked position when the positioning rod (2) is in a final position.

Description

VERIFICATION OF TRANSLATION Australian application for: 1, Thomas Ermer of Wordmaster Translations P/L, 19 High Road, Camberwell, 3124, am the translator of the document(s) attached and I state that the following is a true translation to the best of my knowledge and belief of International patent application PCT/EP2006/062022 (WO 2006/125716 A1), filed on 3.5.2006. Australian application for: Dated: 20.11.2007 Y FOR9 Signature of translator: r S a GERMAN -> ENGLISH Drive system for a rail switch Technical field 5 The invention concerns a drive system for a rail switch according to the preamble of claim 1. With such a drive system it is possible to bring a switch blade of a section of a railway track from one position to another. Currently various drive systems, like 10 mechanical drives via an actuator motor and various cams or electro-hydraulic drives are known. At the same time it is also known (see, for example, DE 3227203 A) to provide in the case of an electro-hydraulic drive a simple positioning rod lock, that is 15 unlocked when the positioning rod is displaced via various mechanical elements, like cams or leading switching cams. At the same time, however, the disadvantage exists that, when vibrations occur, the drive of the positioning rod may carry out an unintentional movement, resulting in a movement of the positioning rod connected via a clutch system. Because the unlocking devices are 20 controlled by the progress of the movement, the positioning rod will be no longer secured in its end position, due to which the switch, connected with the positioning rod, can also move. Consequently the known lock functions reliably only when the drive remains in the planned position and forces act only on the switch. When forces act on the drive, this type of lock may fail. 25 Disclosure of the invention Technical problem 30 The object of the invention is to avoid these disadvantages and to suggest a drive system of the type mentioned in the introduction, wherein a secure locking is assured.

2 Technical solution According to the invention this is achieved by the characterising features of claim 1. 5 By virtue of the proposed measures the advantage will occur, that the lock can be moved from the locked position only when the interlock is moved from its interlocked position by the drive associated with the interlock. Therefore vibrations, should they occur, cannot lead to an unlocking of the lock, so that a 10 switch, provided with a drive system according to the invention, cannot be moved from its respective position even in such a case. From the features of claim 2 the advantage, that the interlock can be effective only in an end position of the positioning rod, becomes obvious. As soon as the 15 positioning rod is moved a little, the arresting projection had left the arresting recess, so that the interlock no longer can return into the interlocked position. Therefore it is not necessary to actuate the drive of the interlock during the entire positioning process, it is sufficient to do this at the commencement of the positioning process. Only when the positioning rod is in one of its end position, 20 can the interlock snap into the arresting recess of the positioning rod and by doing so prevent with its extension piece a movement of the lock in the direction of its unlocked position. For the control of the lock it is advantageous to provide the features of claim 3. In 25 this manner a simple control of the movement of the lock as well as its blocking in the end positions of the positioning rod is possible. The features of claim 4 result in a very simple construction for the drive and the locking of the positioning rod. At the same time the clearance between the carrier 30 arrangement and the drive of the positioning rod ensures that when the interlock is in the released position the locking can be disengaged by a movement of the drive before the positioning rod is moved. The clearance between the arresting recess of the locking body and the body of the lock serves the purpose of tolerance compensation, i.e. the positioning rod can be slightly moved after the 3 interlock has become effective. By virtue of the suggested measures a separate interlock is assigned to each end position of the positioning rod. Due to this a particularly high degree of safety is achieved. 5 In this conjunction it is appropriate to provide the features of claim 5. The features of claim 6 result in the advantage, that an energy supply to the drive of the positioning rod can take place only when both interlocks are in their unlocked positions, so that damaging of the interlocks will be prevented. 10 To enable a continuous information regarding the prevailing status of the switch and its state of locking, the features of claim 7 are advantageously provided. Thus, for example, the setting of the signal to "free" can be made dependent on the fact whether all switches are locked. 15 By virtue of the features of claim 8 a hydraulic interlock is possible. As it will be explained in detail in the description of the drawing, in this case the drive can move only when first the cylinder/piston arrangement had reached its stop. Random pressure fluctuations in the hydraulic system remain ineffective. 20 Short description of the drawings The invention is explained in detail based on the drawing, that schematically shows a drive system for a switch according to the invention. 25 The drive system according to the invention has a drive 1 in the form of a cylinder/piston arrangement, that can be charged with a pressurised fluid. In this case the piston rod 1.1 is held stationary and the cylinder 1.4 can be displaced on it. At the same time this cylinder 1.4 is provided with a carrier 1.2, that with a clearance engages a recess 2.3 of a locking body 2.1. 30 This locking body 2.1 is firmly provided on a positioning rod 2 and furthermore has two arresting recesses 2.2, which interact with the locking bolts 3.1 (for example in the form of pins) of locks 3, which with clearance engage the arresting recesses 2.2. The locking bolts 3.1 are biased downwards by a spring.

4 The cylinder 1.4 of the drive 1 is furthermore firmly joined with an extension piece 1.5 that has a cam 1.3. A scanning sensor 3.3 of the lock 3 rests on this cam, whereby this scanning sensor 3.3, constructed as a roller, is provided on an arm 3.4 of the lock 3. In this conjunction the other side 3.2 of the arm 3.4 interacts 5 with an extension piece 4.1 of an interlock. The lock 3 can be displaced perpendicularly to the positioning rod 2. The interlock 4 essentially has a rod 4.6, that is provided with an arresting projection 4.5 which, when the positioning rod 2 is in the associated end position, 10 engages an arresting recess 4.7 of the positioning rod 2. For this purpose it is biased downwards and/or laterally by a spring, or its weight is sufficient for this purpose. At the same time the rod 4.6 can be lifted with a cylinder/piston (e.g. pneumatic) arrangement 6 (and/or laterally displaced). 15 It is particularly beneficial when the cylinder/piston arrangement 6 is also hydraulically actuated (like the drive 1) and to connect the drive 1 via a pressure reducer parallel with the cylinder/piston arrangement 6. In this case when the line is charged, first the cylinder/piston arrangement 6 is pressurised and consequently is displaced. As long as the rod 4.6 can move, only a low pressure 20 is built up, that is not transmitted by the pressure reducer to the drive 1. Only when the rod 4.6 reaches the stop will a counter-pressure build up. As soon as the limit value (e.g. 6 or 8 bar) of the pressure reducer is exceeded, it transmits this (correspondingly reduced) pressure to the drive 1, that will consequently move. In this manner it is assured purely by hydraulics, that the drive 1 can move 25 only when the rod 4.6 has reached its stop. In addition, by virtue of the pressure reducer it is precluded, that the drive 1 would move resulting from unintentional pressure fluctuations in the hydraulic system. (Such pressure fluctuations are never greater than 6 bar, for example.) 30 An extension piece 4.1 protrudes away from the rod 4.6, that interacts with the arm 3.2, 3.4 of the lock 3 and in the interlocked position illustrated prevents a movement of the left lock 3 in its released position, in which the locking bolt 3.1 would be disengaged from the arresting recesses 2.2.

5 The rod 4.6 controls by means of lugs 4.2 and 4.3 and electric switches 5.1 and 5.2. In this conjunction the switch 5.2 controls via control organs (not illustrated) the energy supply or the supply of the pressurised fluid; only when both switches 5.2 are actuated can the drive 1 be set in operation. The switch 5.2 is connected 5 with an indicating device (not illustrated) or safety devices (not illustrated) and it signals that "the switch is locked and interlocked". To bring the positioning rod 2 from the locked position illustrated into its second position, on the right in the illustrated case, it is necessary to charge the left 10 cylinder/piston arrangement 6 with the pressurised medium, as a result of which the rod 4.6 of the interlock 4 is lifted (and its arresting projection 4.5 is lifted from the arresting recess 4.7 of the positioning rod 4) and the extension piece 4.1 is displaced upwards, due to which an upward movement of the lock 3 becomes possible. 15 At the same time the switch 5.2 gives a signal and enables the supply of the pressurised fluid to the drive 1. Consequently the cylinder 1.4 commences to move to the right. By virtue of this the extension piece 1.5, carrying the cam 1.3, also moves and consequently the scanning sensor 3.3 is lifted and due to this the 20 locking bolt 3.1 is lifted from the arresting recess 2.2 of the locking body 2.1. Due to this the locking of the positioning rod 2 is disengaged and the locking body 2.1 is carried by the carrier 1.2 of the cylinder 1.4 as soon as the cylinder travels past the clearance between the carrier 1.2 and the boundary of the recess 2.3. Since the locking body 2.1 is firmly connected with the positioning rod 2, the positioning 25 rod 2 will also be displaced. When the locking body 2.1 reaches the locking bolt 3.1 of the right lock 3, the locking bolt travels on the sloping surface 2.4 and is lifted by it, what can be carried out without any problem since the arresting projection 4.5 of the right 30 interlock 4 rests on the positioning rod 2 and is lifted by it. As soon as the right arresting recess 2.2 of the locking body 2.1 is reached, the locking bolt 3.1 drops into it. Accordingly the positioning rod 2 reached its end position on the right and the arresting projection 4.5 drops into the arresting recess 4.7 of the positioning rod 2, due to which the extension piece 4.1 of the right interlock 4 will rest on the 6 arm 3.2, 3.4 of the right lock 3, by virtue of which its upward movement will be prevented and the positioning rod will remain securely locked. By doing so the switch 5.1 and 5.2 of the right interlock 4 will also be actuated, 5 signalling a secure locking to the switch monitoring station.

Claims (8)

1. A drive system for a rail switch, the drive comprising a positioning rod (2) connected with the switch blades, said positioning rod being displaceable 5 between two end positions by means of a drive (1), for example a cylinder/piston arrangement, wherein a mechanical lock (3) acting in the end positions of the positioning rod (2) is provided, characterised in that the mechanical lock (3) acts directly on the positioning rod (2) and for this mechanical lock (3) an interlock (4) having a separately controllable drive (6) is 10 provided, said interlock blocking a movement of the lock (3) in the direction of the unlocked position of the positioning rod (2) when it is in an end position.

2. A drive system according to claim 1, characterised in that the interlock (4) comprises a rod (4.6) having an extension piece (4.1), that said rod in an end 15 position of the positioning rod (2) with an arresting projection (4.5) engages an arresting recess (4.7) of the positioning rod (2) while the extension piece (4.1) interacts with the lock (3).

3. A drive system according to claim 2, characterised in that for the control of the 20 lock (3) a cam 1.3, connected with the drive (1) of the positioning rod (2), is provided, on which cam an arm (3.4) of the lock (3), having a scanning sensor (3.3), rests, while this arm (3.4) also interacts with the extension piece (4.1) of the rod (4.6). 25

4. A drive system according to any one of claims 1 to 3, characterised in that on the positioning rod (2) a locking body (2.1) is fastened, that has arresting recesses (2.2) for each of the two end positions which can be engaged with clearance by a locking bolt (3.1), allocated for each end position of the positioning rod (2), and the locking body (2.1) is coupled with a clearance with 30 the drive (1) of the positioning rod (2) via a carrier arrangement (1.2, 2.3).

5. A drive system according to claim 4, characterised in that the locking body (2.1) is provided on both of its ends with sloping surfaces (2.4) for the locking bolt (3.1). 8

6. A drive system according to any one of claims 1 to 5, characterised in that the energy supply to the drive (1) of the positioning rod (2) is controlled by a switch (5.2) that is coercively guided by the interlock and can be disengaged only by the interlock (4) in the released position. 5

7. A drive system according to any one of claims 1 to 6, characterised in that the interlock (4) coercively controls a switch (5.1) that is connected with an indicating device, said switch being activated in the locked position. 10

8. A drive system according to any one of claims 1 to 7, characterised in that the cylinder/piston arrangement (6) and the drive (1) can be hydraulically activated and that the drive (1) is connected via a pressure reducer parallel with the cylinder/piston arrangement (6). 15