EP3865371A1

EP3865371A1 - Apparatus and method for moving the point blades of a railroad switch

Info

Publication number: EP3865371A1
Application number: EP21155540.4A
Authority: EP
Inventors: Maurizio Biagiotti; Alessandro BECCARISI
Original assignee: Silsud Srl
Current assignee: Silsud Srl
Priority date: 2020-02-12
Filing date: 2021-02-05
Publication date: 2021-08-18
Also published as: IT202000002818A1

Abstract

Apparatus (1) for moving the point blades of a railroad switch (500) comprising at least a hydraulic actuator (71) and a displacement group (20) in such a way to, alternately, move at least a point blade (101,102) between two limit positions in which the point blade is, respectively, closed to, or spaced from, a respective rail stock (111,112). It is, furthermore, provided a feeding group (200) comprising a pumping device (205) configured to feed a first predetermined constant flow of the working fluid into a main feeding circuit (210), and at least a second determined flow of the working fluid in a first or a second push chamber (77,78) of the, or each, hydraulic actuator (71) through a respective peripheral feeding circuit (215). This comprises a first and a second control branch (201,202) respectively provided with a first and a second flow measurement device (211,212) and with a first and a second pressure measurement device (221,222) to constantly detect flow and pressure data. The apparatus furthermore comprises at least a servo valve (250) operated by a respective peripheral processing unit (400) to adjust the flow and the pressure of the working fluid in a respective peripheral feeding circuit (215). [Fig. 3]

Description

Field of the invention

The present invention relates to the railway technical field and in particular it relates to an apparatus for moving the point blades of a railroad switch, in particular of the type used in high-speed rail.

Description of the prior art

As known, the apparatuses used for moving the point blades of a railroad switch generally provide at least one shifting actuator which moves, by movement transmission means, the point blades of the railroad switch between two limit positions. More precisely, at the aforementioned limit positions, a point blade is closed to the respective rail stock and is, therefore, called closed point blade, whilst the other point blade is far removed from the respective rail stock and is, therefore, called open point blade. At the opposite limit position, instead, the opposite situation occurs, and, therefore, the point blade that in the previous limit position was the closed point blade is positioned at a predetermined distance from the respective rail stock and therefore it becomes the open point blade, whilst the point blade that previously was the open point blade is arranged closed to the respective rail stock and, therefore, becomes the closed point blade.
The movement from a limit position to the other is caused, as anticipated above, by an actuator, for example a hydraulic actuator which has a predetermined actuation stroke along an actuation direction.
The switch machines of known type, furthermore, provide locking/unlocking devices, which provide the so called switch point locking means that block the point blades in one of the above disclosed limit positions. Normally, the switch point locking means are arranged from an unblocking configuration to a blocking configuration through an over-stroke of the actuator along the actuation direction known as overlapping.
A situation which can occur in the railway switches is that an obstacle, for example a stone, can interpose between the point blade and the rail stock, thus impeding the correct displacement of the railway switch, and in particular to move the point blade closed to the respective rail stock. This situation could cause the control to signal that the railroad switch is in the correct position even if the point blade is bent due to the object that is present between the point blade and the rail stock. This situation is potentially dangerous, in particular in high-speed railway lines, because the train could run on a railroad switch that is not arranged in the correct geometry.
In light of the above, the apparatuses of prior art for displacing the point blades of the railroad switches are not able to satisfy the necessary safety requirements.
An example of a system for displacing the point blades of a switch machine with the aforementioned drawbacks is described in EP3409561 .

Summary of the invention

It is, therefore, an object of the present invention to provide an apparatus for moving the point blades of a railroad switch that is able to overcome the aforementioned drawbacks of the prior art apparatuses.
It is a particular object of the present invention to provide an apparatus for moving the point blades of a railroad switch that is easy to be installed and that is able to assure that the point blades can be moved highly accurately.
It is another object of the present invention to provide an apparatus for moving the point blades of a railroad switch that is able to assure a high safety level for the passengers and the trains running the corresponding stretch of the railway line.
It is still another object of the present invention to provide an apparatus for moving the point blades of a railroad switch that is able to quickly and accurately detect if an obstacle is present between the point blade and the rail stock.
It is also an object of the present invention to provide an apparatus that allows to control both each component and the whole system, communicating any anomaly, or deviation from the optimal functioning.
It is a further object of the present invention to provide a method for moving the point blades of a railroad switch having the same advantages.
These and other objects are achieved by an apparatus for moving the point blades of a railroad switch comprising:

at least a hydraulic actuator comprising a first and a second push chamber;
a displacement group configured to translate along a displacement direction in a first displacement direction, or in a second displacement direction opposite to the first, in such a way to, alternately, move at least a point blade between two limit positions in which the point blade is, respectively, closed to, or spaced from, a respective rail stock, said displacement group being caused to translate along said displacement direction in said first, or second, displacement direction, according to the pressure applied by a working fluid in said first, or second, push chamber;
a feeding group comprising a pumping device configured to feed a predetermined first flow, advantageously constant, of said working fluid into a main feeding circuit, said feeding group being configured, furthermore, to feed at least a determined second flow of said working fluid into said first, or second push chamber of said, or each, hydraulic actuator, through a respective peripheral feeding circuit comprising:
- a first control branch hydraulically connected to said first push chamber, said first control branch being provided with a first flow measurement device configured to constantly detect flow data in said first control branch, and a first pressure measurement device configured to constantly detect pressure data in said first control branch;
- a second control branch hydraulically connected to said second push chamber, said second control branch being provided with a second flow measurement device configured to constantly detect flow data in said second control branch, and a second pressure measurement device configured to constantly detect pressure data in said second control branch;
said feeding group comprising, furthermore, at least a servo valve arranged to hydraulically connect said main feeding circuit with a respective peripheral feeding circuit, said, or each, servo valve being configured to adjust said flow and said pressure of said working fluid in said respective peripheral feeding circuit;
whose main characteristic is to provide, furthermore, a control group comprising:
- a main processing unit operatively connected to said pumping device and configured to set a predetermined flow trend and a predetermined pressure trend for said, or each, peripheral feeding circuit;
- at least a peripheral processing unit operatively connected to said main processing unit, to a respective servo valve, to said respective first and second flow measurement devices, and a respective said first and second pressure measurement device, said, or each, peripheral processing unit being configured to operate said respective servo valve in such a way to adjust the flow in said respective peripheral feeding circuit to obtain, respectively, a flow trend and a pressure trend of said working fluid that is set by said main processing unit, and to send to said main processing unit said flow and pressure data detected in said respective peripheral feeding circuit by said flow and pressure measurement devices, said main processing unit being configured to process said received flow and pressure data and to verify that said respective flow and pressure trends correspond or not to said predetermined flow and pressure trends.

Other technical characteristics of the present invention are set out in the dependent claims.
In particular, if the detected flow and pressure trends and the predetermined flow and pressure trends does not coincide with each other, or anyway if their difference is greater than a predetermined threshold value, said main processing unit is arranged to command the respective peripheral processing unit to operate the respective servo valve in such a way to increase, or decrease, the flow and/or the pressure of the working fluid in the respective peripheral feeding circuit.
In addition, or alternatively, the aforementioned main processing unit can be, advantageously, configured to command at least a peripheral processing unit positioned upstream of the same along the main feeding circuit.
In particular, each peripheral processing unit can be installed at a predetermined distance (D) from the respective actuator. More in particular, the aforementioned distance (D) can be less than, or equal to 8 m, advantageously less than, or equal to 5 m, preferably less than, or equal to 2 m, for example less than, or equal to 1.5 m.
Preferably, each said first and second flow measurement device can be an ultrasonic flow measurement device.
According to a particular embodiment of the invention, a manual operating group can be, furthermore, provided configured to bypass, when it is manually operated in case of emergency, the aforementioned pumping device, and to actuate an auxiliary pumping device. This can be, advantageously, hydraulically connected to a first and a second push chamber of said, or each, hydraulic actuator through a supplementary feeding circuit. In particular, the supplementary feeding circuit can comprise at least a first sequence valve installed along a respective first control branch and a second sequence valve installed along a respective second control branch. More precisely, the first and second sequence valves can be configured to feed the working fluid in the first or second, chamber of the respective actuator.
According to another aspect of the invention, a method for moving the point blades of a railroad switch comprises the steps of:

translating a displacement group along a displacement direction in a first displacement direction, or in a second displacement direction opposite to the first, in such a way to move, alternately, at least a point blade between two limit positions in which the point blade is, respectively, closed to, or spaced from, a respective rail stock, said displacement group being caused to translate along said displacement direction in said first, or second, displacement direction, depending on the pressure applied by a working fluid in a first, or in a second push chamber, defined in at least a hydraulic actuator;
feeding a first predetermined flow of said working fluid into a main feeding circuit and at least a determined second flow of said working fluid into said first, or second push chamber of said, or each, hydraulic actuator, through a respective peripheral feeding circuit comprising a first control branch hydraulically connected to said first push chamber and a second control branch hydraulically connected to said second push chamber;
setting a predetermined flow trend and a predetermined pressure trend for said, or each, peripheral feeding circuit by a main processing unit;
adjusting said, or each, determined second flow and pressure of said working fluid in said, or each, respective peripheral feeding circuit by at least a respective servo valve arranged to hydraulically connect said main feeding circuit with a respective peripheral feeding circuit, said adjusting step being carried out by operating said, or each, servo valve by a respective peripheral processing unit operatively connected to said main processing unit and to said servo valve;
detecting flow and pressure data in said first control branch and in said second control branch;
sending said detected flow and pressure data to said peripheral processing unit;
sending said detected flow and pressure data from said peripheral processing unit to said main processing unit;
processing by said main processing unit said flow and pressure data received for verifying if the corresponding flow and pressure trends of said, or each, peripheral feeding circuit correspond, respectively, to said predetermined flow and pressure trends.

Brief description of the drawings

The invention will now be shown with the following description of its exemplary embodiments, exemplifying but not limitative, with reference to the attached drawings in which:

Fig. 1 diagrammatically shows a front view partially sectioned of a component of the apparatus, according to the invention, to move a railway switch;
Fig. 2 diagrammatically shows a possible hydraulic actuator provided by the invention to move a railway switch, according to the invention;
Fig. 3 shows a first scheme of the hydraulic circuit and related electronic of control provided by the apparatus for moving a railway switch, according to the invention;
Fig. 4 shows a general scheme of functioning of the apparatus according to the invention in the case of a railway switch comprising more than 2 switch machines;
Fig. 5 shows a possible scheme of functioning of the apparatus according to the invention in the case of a railway switch with 3 switch machines;
Fig. 6 diagrammatically shows in a plan view a detail of a part of a railway switch when a situation occurs that could compromise the correct functioning of the same;
Fig. 7 shows an enlargement of the portion of the railway switch of figure 6 where the potentially dangerous situation occurs.

Detailed description of some exemplary embodiments of the invention

As diagrammatically shown in figure 1, an apparatus 1 for moving the point blades of a railroad switch 500 comprises a displacement group provided with at least an operating tie-rod20. More precisely, in the case of a mobile crossing, the operating tie-rod 20 is engaged with a point blade only at an end. Instead, at the point blade frame, the operating tie-rod 20 can be engaged, at opposite ends 21 and 22, respectively, with a first and a second point blades 101 and 102 through respective movement transmission members.
In particular, the displacement group 20 is arranged to translate along a displacement direction 120 to cause a movement of the only point blade fixed to it in the case of the mobile crossing, or the first and second point blades 101 and 102, in the case of the point blade frame, between two limit positions. In this way, depending on that the displacement group 20 slides along the aforementioned displacement direction 120, in a first direction, or in a second direction opposite to the first, the point blade, 101, 102, is arranged between a position closed to the respective rail stock 111, or 112, whereby it is called closed point blade, and, therefore, the other point blade 102, or 101, is positioned in a position open from the respective rail stock 112, or 111, whereby it is called open point blade, and vice versa.
It is, then, provided at least a hydraulic actuator 71 arranged to cause the displacement group 20 to translate along the aforementioned displacement direction 120. More precisely, the, or each, hydraulic actuator 71, comprises a first and a second push chamber 77 e 78 opposite to each other.
In particular, the displacement group 20 is caused to slide in the aforementioned first, or second, displacement direction depending on the pressure applied in the first and/or the second push chamber 77, or 78, by the working fluid.
In the case diagrammatically shown as an example in figure 2, a predetermined number of double acting hydraulic actuators is provided. In this case, the hydraulic actuator 71 is provided with a fixed stem 72 supported at opposite ends by supports 76a and 76b. More in particular, the double acting actuator 71 is provided with a main hollow body 75 provided with a longitudinal cavity 79 and slidingly mounted on the fixed stem 72. This is configured in such a way to divide the longitudinal cavity 79 in a first and a second push chamber opposite to each other. However, according to a first embodiment not shown in figure for simplicity, the possibility is also provided to use a first and a second single acting hydraulic actuator, respectively provided with the first and the second chamber 77 and 78 of equal cross section. In this case, for moving the displacement group 20 in a respective translation direction along the displacement direction 120 is used a single respective chamber 77, or 78. In this way pushing on chambers that are different, but have the same cross section, a symmetrical pushing action in the two directions is obtained under the same pressure and with an equivalent velocity due to the same volumes.
The apparatus 1 comprises, furthermore, a blocking/unblocking group 50 arranged to move from a blocking configuration, in which impedes the displacement group, in particular the operating tie-rod 20, to translate along the displacement direction 120, to an unblocking configuration, in which, instead, it allows the same to translate. More in particular, the blocking/unblocking group 50, also known as switch point locking group, is configured in such a way to be arranged in the blocking configuration when the actuation group is arranged in a position such that the point blade 101, or 102, is arranged in a position closed to the respective rail stock 111, or 112.
As diagrammatically shown in figure 3, the apparatus 1 for moving the point blades of a railroad switch, according to the invention, provides, furthermore, a feeding group 200 comprising a pumping device 205 configured to feed a first constant flow of working fluid into a main feeding circuit 210.
The feeding group 200 is configured, furthermore, to feed at least a second flow of the aforementioned working fluid in the first or second push chamber 77, or 78, of the, or each, hydraulic actuator 71, through a respective peripheral feeding circuit 215. More precisely, the peripheral feeding circuit 215 comprises a first control branch 201 which is hydraulically connected to the first push chamber 77, and a second control branch 202 which is hydraulically connected to the second push chamber 78. Advantageously, the first control branch 201 is provided with a first flow measurement device 211 configured to constantly detect flow data in said first control branch 201, and, preferably, of a first pressure measurement device 221 configured to constantly detect pressure data in said first control branch 201. Analogously, the second control branch 202 is provided with a second flow measurement device 212 configured to constantly detect the flow data in the second control branch 202, and, preferably, of a second pressure measurement device 222 configured to constantly detect pressure data in the second control branch 202 same.
The feeding group 200 comprises, furthermore, at least a servo valve 250 arranged to hydraulically connect the main feeding circuit 210 with a respective peripheral feeding circuit 215. More in detail, the servo valve 250 is configured to adjust the flow of the working fluid in the first and second chambers 77, and 78. The, or each, servo valve 250 e, furthermore, advantageously configured to adjust the pressure of the working fluid in the respective peripheral feeding circuit 215. According to the invention, furthermore, the apparatus 1 comprises a control group 300. More in particular, the control group 300 comprises a main processing unit 350 operatively connected to the aforementioned pumping device 205 and ad at least a peripheral processing unit 400 associated to a respective servo valve 250. The main processing unit 350, for example comprising a first and a second CPU redundant with each other, is configured to set a determined flow trend and a predetermined pressure trend in each of the peripheral feeding circuits 215 and to verify if the aforementioned flow and pressure trends detected in each of the aforementioned peripheral feeding circuits 215 correspond to respective predetermined flow and pressure trends. More in particular, the, or each, peripheral processing unit 350 is arranged to operate a respective servo valve 250 to adjust the flow and the pressure of the working fluid in the respective peripheral feeding circuit 215. The, or each, peripheral processing unit 400 is, furthermore, operatively connected to the aforementioned first and second flow measurement devices 211 and 212, and, advantageously, to the aforementioned first and second pressure devices 221 and 222 of the respective peripheral feeding circuit 215. More in particular, the, or each, peripheral processing unit 400 receives from the first and/or the second flow measurement device 211, 212, and from the first and/or the second pressure measurement device 221, 222, at predetermined intervals of time, respectively flow data e pressure data, that provide to send to the main processing unit 350. More precisely, each peripheral processing unit 400 communicates with the main processing unit 350 through a predetermined number of lines of data, for example through a first and a second lines of data 301 and 302. The main processing unit 350 elaborates the flow and pressure data and verify if the respective flow and pressure trends correspond to the predetermined flow and pressure trends in the respective peripheral feeding circuits 215. In the case that, the detected flow and pressure trends do not correspond to the predetermined flow and pressure trends, the main processing unit 350 commands the peripheral processing unit 400 to operate the respective servo valve 250 in order to increase, or decrease, the flow and/or the pressure of the working fluid in the respective peripheral feeding circuit to bring the detected flow and pressure trends back to the respective predetermined flow and pressure trends. The present invention allows, in particular, to considerably increase the accuracy of the apparatus for moving the point blades of a railway switch with respect to the prior art apparatuses. In fact, the flow and pressure data of the working fluid detected by the first and second flow and pressure measurement devices 211, 212 and 221, 222 in the, or each, peripheral feeding circuit 215, are sent to the respective peripheral processing unit which is at the points where the aforementioned parameters are detected, or however near the same, and, therefore, it is highly reliable, because it is not affected, or at least not significantly affected, by measurement errors due, for example, to pressure drop along the line. Therefore, also the adjustment of the flow by the adjustment devices provided by the present invention can be carried out very accurately and quickly. In particular, each peripheral processing unit 300 can be installed at a predetermined distance from the respective actuator 71 less than, or equal to 8 m, advantageously less than, or equal to 5 m, preferably less than, or equal to 2 m. It is, however, appropriate to note that differently from the prior art solutions, the apparatus 1, according to the invention, allows to position the servo valves 250 at a predetermined distance D from the respective actuator 71 independently from the type of railway switch on which it is installed.
Another advantage of the present invention with respect to the prior art apparatuses is to significantly simplify the installation of the whole system, that means both of the control group and the feeding group.
According to a preferred embodiment, each flow measurement device 211 and 212 is an ultrasonic flow measurement device. This particular solution allows to avoid pressure drop and interactions with the fluid and therefore guarantees to have a highly accurate measurement of the flow and, therefore, of the position of the actuator 71.
The technical solution provided by the present invention is particularly advantageous in the case of a railway switch 500 comprising 2, or more switch machines 100. At this regard, in figure 5 a scheme is shown of the hydraulic circuit and the related logic of control if 2, or more, actuators 71 are provided. In particular, if the i-th actuator 71i is taken into consideration, the relative components for controlling the i-th peripheral feeding circuit 215i can be diagrammatically illustrated.
For example, in the scheme of figure 5, the apparatus 1 can comprise 3 hydraulic actuators 71a, 71b e 71c. In particular, each peripheral processing unit 400a-400c associated to a respective actuator 71a-71c, is configured, as anticipated above with reference to the scheme of figure 3, to operate a respective servo valve 250a-250c in such a way to have in the respective peripheral feeding circuit 215a-215c a determined flow and pressure trend. More in particular, each peripheral processing unit 400a-400c is configured to receive the flow and pressure data detected by the flow and pressure measurement devices 211a-211c, 212a-212c, and by the pressure measurement devices 221a-221c, and 222a-222c installed sui respective first and second branches 201a-201c and 202a-202c of each peripheral feeding circuit 215a-215c. More in particular, each peripheral processing unit 400a-400c, sends the aforementioned flow and pressure data to the main processing unit 350. This is arranged to compare the flow and pressure trends detected at each peripheral feeding circuit 215a-215c and received by the peripheral processing units 400a-400c with respective predetermined flow and pressure trends. If the comparison result is that one, or more, flow and/or pressure trends do not correspond, or more precisely, deviate more than predetermined threshold value, from the respective flow and/or pressure trends, the main processing unit 350 commands the, or each, peripheral processing unit 400a-400c to operate the respective servo valve 250a-250c in such a way to increase, or decrease the flow and/or the pressure in the respective peripheral feeding circuit 215a-215c. This realignment operation is carried on up to bring each flow trend and each pressure trend to be equal to the respective flow and pressure trends, or anyway to deviate from the same less than the aforementioned predetermined threshold value.
According to an embodiment of the invention, the main processing unit 400 can be configured to operate the pumping device 205 in such a way to feed into the main feeding circuit 210 a first constant flow of the working fluid at a first predetermined starting pressure p1. The, or each, peripheral processing unit, for example the 3 peripheral processing units 400a-400c of figure 5, are arranged to operate the respective servo valves 250a-250c in such a way to have in each peripheral feeding circuit 215a-215c a respective predetermined pressure p2a-p2c.
According to a particular embodiment of the invention, the control group 300 can be advantageously configured to reduce the pressure in each peripheral feeding circuit 215a-215c up to reaching a respective second predetermined value p2*a-p2*c, in the ending part of the closing step of the point blade 101, or 102, to the respective rail stock 111, or 112.
In particular, the control group 300 can be configured in such a way that the pressure reduction from the starting pressure p2a-p2c to the predetermined value p2*a-p2*c in each peripheral feeding circuit 215-215c is controlled by the main processing unit 350 to each peripheral processing unit 400a-400c which operates accordingly the respective servo valve 250a-250c.
In particular, the pressure values p2*a-p2*c are set in such a way to correspondingly reduce the pushing force Fsa-Fsc applied by each hydraulic actuator 71a-71c at a predetermined position, next to the limit position of the different actuators 71a-71c. In this way, if between the point blade 101, or 102 and respective rail stock 111, or 112, an obstacle 150 is present, such as a stone, or a bolt, and, therefore, the external force acting on the hydraulic actuator 71a-71c is greater than the aforementioned value of the reduced force, for example a predetermined value F*, the further stroke of the actuator 71a-71c, i.e. of the respective main hollow body 75 is impeded and, therefore, the railroad switch 500 blocks and signals the danger. At the same time the pushing force Fs1-Fs2 of each actuator 71a-71c corresponding to the pressure p2*a-p2*c is, however, sufficient to allow positioning of the point blades 101 and 102 in the respective limit positions, if the aforementioned situation does not occur. More in particular, the pressure reduction from the starting value p2a-p2c up to the aforementioned value p2*a-p2*c can be carried out by each servo valve 250a-250c and monitored by the respective pressure measurement device 222a-222c.
More in detail, the aforementioned pressure reduction can be carried out by each servo valve 250a-250c when the respective actuator 71-71c is arranged in a predetermined position close to the limit position of the same, i.e. when the point blade 101, or 102, is arranged close to the respective rail stock 111, or 112, i.e. is positioned at a distance from the rail stock less than a predetermined limit distance d*. This can be, for example, equal to, or less than 30 mm, advantageously equal to, or less than 25 mm, preferably equal to, or less than 20 mm.
More precisely, the position of each actuator 71a-71c is computed instant by instant by the main processing unit 350 on the basis of the flow data received by the respective peripheral processing units 400a-400c and detected by the respective first and second flow and pressure devices 211a-211c; 212a-212c and 221a-221c; 222a-222c.
Advantageously, in determined circumstances, for example if an obstacle is present between point blade 101, or 102, and rail stock 111, or 112, the position of one, or more, actuators 71a-71c of the apparatus 1 detected, will not correspond to a predetermined position. In this case, therefore, the main processing unit 350 will be arranged to command at least a peripheral processing unit 400a-400c to operate the respective servo valve 250a-250c in such a way to adjust the flow in the first chamber 77a-77c, or in the second chamber 78a-78c, of the respective actuator 71a-71c to position the same in a determined position such that an excessive bending of the point blade 101, or 102 is avoided.
The aforementioned limit distance d* will depend, in general, on the geometry of the railway switch 500, on the position of the actuator 71 with respect to the railway switch, on the material of which the point blade 101, or 102 is made of, and other constructive parameters.
The technical solution described above, and adopted by the present invention, allows to avoid dangerous situations that could cause the derailment of the train, if between the point blade and the rail stock an obstacle is present, for example a stone 150. In fact, if this situation occurs between two successive actuators 71a and 71b (see figures 6 and 7) is not detected by the control systems of prior art. In fact, in the prior art solutions, the pressure of the working fluid in the feeding circuit is constant and, however, sufficiently high to bring the successive actuators to the limit position, even if an obstacle 150 is present. Therefore, in the prior art railway switches it is not possible to detect the presence of the obstacle even if the bending of the point blade is such to cause a derailment of the train.
Instead, the present invention, thanks to the functioning described above, allows to immediately detect if an obstacle 150 is present and to take prompt actions to deactivate the railway switch and to signal the malfunctioning, in order to immediately secure the railway line. Furthermore, the fact to provide a pressure reduction only near the rail stock 111, or 112, allows, in particular, to optimize the mechanism because it provides to verify if the railway switch can be used only if an obstacle 150 is present at a very critical zone, i.e. only if the obstacle is present near the rail stock 111, 112.
According to another alternative embodiment of the invention, a manual operating group 600 can be, furthermore, provided configured to bypass the pumping device 205, when it is operated manually, in case of emergency. More in particular, when the manual operating group 600 is operated, an additional pumping device 206 is operated. This is hydraulically connected through a supplementary feeding circuit 210' to at least a hydraulic actuator 71. More precisely, the supplementary feeding circuit 210' is provided with a first sequence valve 216 installed along a respective first control branch 201 and to a second sequence valve 217 installed along a respective second control branch 202. Each valve of sequence 216, or 217, is configured to "detects" the pressure of the working fluid when the aforementioned auxiliary pumping device 206 is manually operated, and to feed the working fluid, respectively, in the first, or second, chamber of the respective actuator 71 through the aforementioned supplementary feeding circuit 210'.
As diagrammatically shown in figure 3, the main feeding circuit 210 can provide, furthermore, a switch, for example 6-way switch 204, to move from the motorized mode and, therefore, adjusted by the aforementioned control group 300, to the manual mode, in which the pumping device 205 is bypassed and the working fluid is caused to move in the circuit by the manual pumping device 206 as described above. The pumping device 206 can be for example operatively connected to the aforementioned switch by a selector valve 207 to select the first, or the second, control branch of the, or each, peripheral feeding circuit to be fed with the working fluid.
According to an embodiment provided by the invention and diagrammatically shown in figure 4, the main feeding circuit 210 can be provided with measurement devices of any type, for example a pressure measurement device 204 arranged to measure the pressure of the working fluid and to send the respective pressure data to the main processing unit 350, in addition to a level measurement devices, non-return valves etc. as diagrammatically shown as an example in figure 4.
Still with reference to figure 4, the apparatus 1, according to the invention, can furthermore provide an additional electrical control unit 450 arranged to be connected to the main feeding circuit 210 and, therefore, to the, or each, peripheral feeding circuit 215, for example to carry out ordinary, or extraordinary, maintenance operations, of the same and the respective hydraulic actuators 71. More in particular, the aforementioned additional electrical control unit 450 can be connected to the main feeding circuit 210 by at least a interface device 455 configured to alternatively and selectively connect the additional electrical control unit 450 with the first, or the second branch, of the, or each, peripheral feeding circuit in addition to the manual actuation circuit 210'.
The foregoing description exemplary embodiments of the invention will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt for various applications such embodiment without further research and without parting from the invention, and, accordingly, it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiments. The means and the materials to realize the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology that is employed herein is for the purpose of description and not of limitation.

Claims

Apparatus (1) for moving the point blades of a railroad switch (500) comprising:
- at least a hydraulic actuator (71) comprising a first and a second push chamber (77,78);

- a displacement group (20) configured to translate along a displacement direction (120) in a first displacement direction, or in a second displacement direction opposite to the first, in such a way to move, alternately, at least a point blade (101,102) between two limit positions in which the point blade is, respectively, closed to, or spaced from, a respective rail stock (111,112), said displacement group (20) being caused to translate along said displacement direction (120) in said first, or second, displacement direction, according to the pressure applied by a working fluid in said first, or second, push chamber (77,78);

- a feeding group (200) comprising a pumping device (205) configured to feed a first predetermined constant flow of said working fluid into a main feeding circuit (210), said feeding group (200) being, furthermore, configured to feed at least a second determined flow of said working fluid into said first, or second push chamber (77,78) of said, or each, hydraulic actuator (71), through a respective peripheral feeding circuit (215) comprising:
- a first control branch (201) hydraulically connected to said first push chamber (77), said first control branch (201) being provided with a first flow measurement device (211) configured to constantly detect flow data in said first control branch (201), and a first pressure measurement device (221) configured to constantly detect pressure data in said first control branch (201);

- a second control branch (202) hydraulically connected to said second push chamber (78), said second control branch (202) being provided with a second flow measurement device (212) configured to constantly detect flow data in said second control branch (202), and a second pressure measurement device (222) configured to constantly detect pressure data in said second control branch (202);

said feeding group (200) comprising, furthermore, at least a servo valve (250) arranged to hydraulically connect said main feeding circuit (210) with a respective peripheral feeding circuit (215), said, or each, servo valve (250) being configured to adjust said flow and said pressure of said working fluid in said respective peripheral feeding circuit (215);
said apparatus (1) being characterized in that it, furthermore, provides a control group (300) comprising:
- a main processing unit (350) operatively connected to said pumping device (205) and configured to set a predetermined flow trend and a predetermined pressure trend for said, or each, peripheral feeding circuit (215) ;

- at least a peripheral processing unit (400) operatively connected to said main processing unit (350), to a respective servo valve (250), to said respective first and second flow measurement devices (211,212) and to said respective first and second pressure measurement devices (221,222), said, or each, peripheral processing unit (400) being configured to operate said respective servo valve (250) in such a way to adjust the flow and the pressure in said respective peripheral feeding circuit in order to obtain respectively a flow trend and a pressure trend of said working fluid that is set by said main processing unit (350), and to send to said main processing unit (350) said flow and pressure data detected in said respective peripheral feeding circuit (215) by said flow measurement devices (211,212) and by said pressure measurement devices (221,222), said main processing unit (350) being configured to process said received flow and pressure data and to verify that said respective flow and pressure trends correspond or not to said predetermined flow and pressure trends.
Apparatus for moving the point blades of a railroad switch, according to claim 1 in cui if said detected flow and pressure trends and said predetermined flow and pressure trends does not coincide with each other, or their difference is greater than a predetermined threshold value, said main processing unit (350) is arranged to command at least a peripheral processing unit (400) to operate said respective servo valve (250) in such a way to increase, or decrease, said flow and/or said pressure of said working fluid in the respective peripheral feeding circuit (215).
Apparatus for moving the point blades of a railroad switch, according to claim 1, or 2, wherein each said first and second flow measurement device (211,212) is an ultrasonic flow measurement device.
Apparatus for moving the point blades of a railroad switch according to any of the previous claims wherein a plurality of hydraulic actuators (71a-71c) is provided, and wherein said main processing unit (350) is configured to command said plurality of peripheral processing units (400a-400c) to operate a respective plurality of servo valves (250a-250c), in such a way to feed into said respective peripheral hydraulic circuit (215a-215c) a respective flow of said working fluid at a respective pressure in order to synchronously move said plurality of hydraulic actuators (71a-71c).
Apparatus for moving the point blades of a railroad switch, according to any of the previous claims wherein said main processing unit (350) is configured to command said, or each, peripheral processing unit (400a-400c) to operate a respective servo valve (250a-250c) in such a way to reduce the pressure in said respective peripheral feeding circuit (215a-215c) from a starting pressure (p2a-p2c) up to reach a predetermined final value (p2*a-p2*c), starting from a predetermined position of the respective hydraulic actuator (71a-71c), in such a way to correspondingly reduce the pushing force (Fa-Fc) applied by said, or each, hydraulic actuator (71a-71c) up to reach a predetermined value (Fa*-Fc*) thus avoiding a further stroke of the same if an external force is present that is greater than said reduced pushing force.
Apparatus for moving the point blades of a railroad switch, according to claim 5, wherein said main processing unit (350) is configured to command said, or each, peripheral processing unit (400a-400c) to operate said respective servo valve (250a-250c) in such a way to start to reduce said starting pressure (p2a-p2c) when said point blade (101,102) is positioned at a distance (d) from the respective rail stock (111,112) that is less than a predetermined distance (d*), thus reducing said pressure of said working fluid up to reach said predetermined value (p2*a-p2*c) only in proximity of said limit position.
Apparatus for moving the point blades of a railroad switch, according to claim 6, wherein said distance of said point blade (101,102) from said respective rail stock (111,112) is determined by said main processing unit (350) according to said flow data detected by said first, or second, flow measurement device (211a-211c;212a-212c) and sent to said main processing unit (350) by said, or each, respective peripheral processing unit (400a-400c).
Apparatus for moving the point blades of a railroad switch, according to any of the previous claims wherein a manual operating group (600) is, furthermore, provided configured, when is manually operated, to bypass said pumping device (205) in case of emergency, and to operate an auxiliary pumping device (206).
Apparatus for moving the point blades of a railroad switch, according to claim 8 wherein said auxiliary pumping device (206) is hydraulically connected to said first and second pushing chambers (77,78) of at least a hydraulic actuator (71) through a supplementary feeding circuit (210').
Apparatus for moving the point blades of a railroad switch, according to claim 9 wherein said supplementary feeding circuit (210') comprises at least a first sequence valve (216) installed along a respective first control branch (201), and a second sequence valve (217) installed along a respective second control branch (202), said, or each, first and said, or each, second sequence valve (216,217) being configured to feed said working fluid into said respective first, or second, push chamber (77,78) of said respective hydraulic actuator (71).
Apparatus for moving the point blades of a railroad switch, according to any of the previous claims wherein each peripheral processing unit (400) is installed at a predetermined distance (D) from said respective hydraulic actuator (71) that is less than, or equal to 8 m.
Apparatus for moving the point blades of a railroad switch, according to any of the previous claims in cui each peripheral processing unit (400) is installed at a predetermined distance (D) da said respective hydraulic actuator (71) that is less than, or equal to 5 m.
Apparatus for moving the point blades of a railroad switch, according to any of the previous claims in cui each peripheral processing unit (400) is installed at a predetermined distance (D) da said respective hydraulic actuator (71) that is less than, or equal to 2 m.
Apparatus for moving the point blades of a railroad switch, according to any of the previous claims wherein said first and second push chambers (77,78) are the opposite chambers of the same double acting hydraulic actuator, or the respective chambers of a first and a second single acting hydraulic actuator.
Method for moving the point blades of a railroad switch comprising the steps of:
- translating along a displacement direction in a first displacement direction, or in a second displacement direction opposite to the first, a displacement group in such a way to move, alternately, at least a point blade between two limit positions in which the point blade is, respectively, closed to, or spaced from, a respective rail stock, said displacement group being caused to translate along said displacement direction in said first, or second, displacement direction, depending on the pressure applied by a working fluid in a first, or in a second push chamber, defined in at least a hydraulic actuator;

- feeding a first predetermined flow of said working fluid into a main feeding circuit and at least a determined second flow of said working fluid into said first, or second push chamber of said, or each, hydraulic actuator, through a respective peripheral feeding circuit comprising a first control branch hydraulically connected to said first push chamber and a second control branch hydraulically connected to said second push chamber;

- setting a predetermined flow trend and a predetermined pressure trend for said, or each, peripheral feeding circuit by a main processing unit;

- adjusting said, or each, determined second flow and pressure of said working fluid in said, or each, respective peripheral feeding circuit by at least a respective servo valve arranged to hydraulically connect said main feeding circuit with a respective peripheral feeding circuit, said adjusting step being carried out by operating said, or each, servo valve by a respective peripheral processing unit operatively connected to said main processing unit and said servo valve;

- detecting flow and pressure data in said first control branch and in said second control branch;

- sending said detected flow and pressure data to said peripheral processing unit;

- sending said flow and pressure data detected by said peripheral processing unit to said main processing unit;

- processing by said main processing unit said received flow and pressure data to verify if the corresponding flow and pressure trends of said, or each, peripheral feeding circuit correspond, respectively, to said predetermined flow and pressure trends.