Patent Description:
Such a detection device is intended to be arranged on the front of the railway vehicle, so that it is actuated when the railway vehicle comes colliding with an obstacle, or when the vehicle wheels climb the rail and drop off the rail.

It is already known, from prior art, a detection device comprising a transverse beam intended to be arranged on a front part of the railway vehicle.

An obstacle is detected when said obstacle comes colliding with the transverse beam, with an impact force above a first predefined threshold, usually above <NUM> daN.

A derailment is detected when the rail comes colliding with the transverse beam, with an impact force above a second predefined threshold, usually above <NUM> daN. This happens when the vehicle wheels climb the rail and drop off the rail.

<CIT> discloses an obstacle and derailment sensing system of a train. The system comprising an obstacle detection beam <NUM>, a support <NUM> to hold the sensing system, a pivoting member <NUM> holding the detection beam <NUM> and rotatably connected to sensing units <NUM>. The sensing unit <NUM> may be an ON/OFF switch for generating a ON/OFF signal when the rotary unit is rotated at a contact point after hitting an obstacle.

<CIT> discloses an obstacle deflector <NUM> comprising a sensor <NUM> for generating a collision signal by relative motion between a collision beam <NUM>, arm <NUM> and a support <NUM>. The arm is connected to the support through an articulated joint <NUM>.

<CIT> discloses an obstacle and derailment detection to automatically stop a railway vehicle after collision with an obstacle or the rail. A sensor unit generates a contact signal when the rotation displacement of a rotary shaft connected with a sensing bar is over a set value.

The present invention aims to propose a detection device able to detect both obstacles and derailment, while being more economical than devices from prior art.

To this end, the invention relates to an obstacle and derailment detection device according to claim <NUM>.

Because of the pivot connection, the rod swings towards the contact actuator when the transverse beam collides with an obstacle in the longitudinal direction.

Besides, the transverse beam is also able to swing in case of derailment. Indeed, in case of derailment, the transverse beam comes in contact with the rail, so that it swings backward because of the speed of the railway vehicle.

In both cases, the rod swings towards the contact actuator. Thus, the contact actuator can be actuated in both cases of obstacle or derailment.

The detection device of the invention does not need to differentiate the two cases of obstacle or derailment, by involving a same action (e.g. emergency braking) in the same way in both cases. As a result, the detection device according to the invention is very simple, thus it is economical.

A detection device according to the invention can also comprise any of following features, without departing from the scope defined by the appended claims:.

The invention also relates to a railway vehicle, caracterized in that it comprises the detection device as defined above, arranged on a front part of the vehicle.

Preferentially, the railway vehicle comprises a leading bogie having a bogie frame, the detection device being arranged in front of the leading bogie, the support being fastened to the bogie frame.

Optionally, the railway vehicle comprises an emergency braking system, connected to the contact actuator to be able to receive the emergency signal, the emergency braking system being configured to implement an emergency braking operation when receiving the emergency signal.

Various aspects and advantages of the invention will be highlighted in the following description, given only as a non-exhaustive example, and made regarding the accompanying figures, as follows:.

<FIG> shows an obstacle and derailment detection device <NUM> according to an example of embodiment. The detection device <NUM> is attached to a bogie <NUM> of a railway vehicle, the railway vehicle extending in a longitudinal direction X.

In this specification, the wordings "front", "rear" or "backward" are defined in the longitudinal direction X, regarding the direction movement of the railway vehicle.

The bogie <NUM> is a leading bogie, i.e. the first bogie from the front of the railway vehicle. Thus, the detection device <NUM> is arranged at a front part of the railway vehicle.

The bogie <NUM> comprises a bogie frame <NUM>, forming a structural part of the bogie.

The bogie frame <NUM> comprises two front longitudinal beams <NUM> holding a front axle <NUM>. The front axle <NUM> extends in the transverse direction Y, and it bears two front wheels <NUM>.

It should be noticed that the bogie <NUM> could also comprise any usual equipment, such as motorization means, etc..

The bogie frame <NUM> also comprises two (not shown) rear longitudinal beams holding a rear axle. The rear axle bears two rear wheels.

The detection device <NUM> comprises a transverse beam <NUM>, extending in a transversal direction Y perpendicular to the longitudinal direction X. In this specification, we also consider a vertical direction Z that is perpendicular to the longitudinal direction X and to the transversal direction X.

The transverse beam <NUM> is preferentially made of aluminum.

The transverse beam <NUM> is arranged in front of the front axle <NUM>, parallel to this front axle <NUM>.

The detection device <NUM> comprises at least one support <NUM> intended to be fixed on the railway vehicle. More particularly, the detection device <NUM> comprises two supports <NUM>, each support <NUM> being fixed on a respective of the front longitudinal beams <NUM>, at the front of said front longitudinal beams <NUM>.

For each support <NUM>, the detection device <NUM> comprises one rod <NUM> holding the transverse beam. Each rod <NUM> is preferentially made of aluminum.

One of the supports <NUM>, and the corresponding rod <NUM>, are shown with more details on <FIG>.

The support <NUM> is fastened to the corresponding front longitudinal beam <NUM> by fastening means <NUM>, for instance comprising screws or any other suitable fastening means.

The detection device <NUM> comprises a pivot connection <NUM> defined around an axis parallel to the transverse direction, for connecting the rod <NUM> to the support <NUM>. The support <NUM> comprises a support bracket <NUM> holding this pivot connection <NUM>.

For instance, the support <NUM> is made of a bent plate comprising a first part for fastening to the front longitudinal beam <NUM> and a second part forming the support bracket <NUM>, with a bent part separating these parts. The first part extends substantially vertically, and the second part extends substantially horizontally.

The rod <NUM> comprises an upper part 22a connected to the support <NUM> by means of the pivot connection <NUM>, and a lower part 22b fastened to the transverse beam <NUM>, in particular by means of a screw.

Because of the pivot connection <NUM>, the rod <NUM> is able to swing around the axis. Thus, the transverse beam <NUM> is also able to swing around the axis.

The detection device <NUM> also comprises retaining means <NUM> for retaining the transverse beam <NUM> in a rest position while not subjected to a force or while subjected to an angular couple inferior to a predefined threshold.

In the shown example, the retaining means <NUM> comprise at least first <NUM> and second <NUM> complementary magnetic elements. The first magnetic element <NUM> is arranged on the rod <NUM>, preferentially above the pivot connection <NUM>. The second magnetic element <NUM> is arranged on the support <NUM>, so that it is in contact with the first magnetic element <NUM> in the rest position.

For example, the first magnetic element <NUM> is a metal disc, and the second magnetic element <NUM> is a permanent magnet.

Said predefined threshold depends on the magnetic force of the first <NUM> and second <NUM> complementary magnetic elements. A man skilled would know how to determine which magnetic elements to use as a function of the desired threshold.

As it is shown on <FIG>, each rod <NUM> is preferentially shaped so that the transverse beam <NUM> is arranged backward the axis of the pivot connection <NUM>, regarding the longitudinal direction X, so that the transverse beam <NUM> is able to swing anticlockwise around the axis when submitted to a force in a vertical upward direction.

The shape of the rod <NUM> facilitates the swing of the transverse beam <NUM> in case of derailment. Indeed, in case of derailment, the transverse beam <NUM> comes colliding with the rail in a vertical direction, so that the transverse beam is submitted to a force in a vertical upward direction. The shape of the rod <NUM> then makes the transverse beam <NUM> and the rod <NUM> swing towards the contact actuator.

It should be noticed that the speed of the railway vehicle also participates in swinging the rod <NUM> when the transverse beam <NUM> is in contact with the rail.

For instance, the upper part 22a is substantially straight and substantially vertical, and the lower part 22b is substantially straight and forms an angle with the upper part 22a, for instance an angle between <NUM>° and <NUM>°, for instance substantially equal to <NUM>°. This angle is determined as a function of said predefined threshold, as an optimal angle allowing the magnetic means <NUM> to detach when the transverse beam <NUM> is subjected to a force in the vertical upward direction that corresponds to a derailment, as specified hereafter.

It appears that, when the transverse beam <NUM> is pushed backward by a longitudinal force the longitudinal direction X, or pushed upward by a vertical force in the vertical direction Z, it swings around the axis of the pivot connection <NUM> if the longitudinal force or the vertical force generates an angular couple superior to the angular couple generated by the magnetic force of the magnetic means <NUM>. Thus, the predefined threshold corresponds to the angular couple generated by the magnetic force of the magnetic means <NUM>.

In case of an obstacle on the tracks, the transverse beam <NUM> comes colliding with this obstacle, causing a longitudinal force. If this longitudinal force is not enough to detach the magnetic means, the transverse beam <NUM> stays in its rest position: the obstacle is not large enough to be considered as a danger for the railway vehicle.

Usually, the magnetic means <NUM> are configured to detach if the longitudinal force is greater than <NUM> daN.

In case of a derailment, the wheels <NUM> climb the rail and drop off the rail, so that the rail comes colliding with the transverse beam <NUM> with an upward vertical force, and pushed backward because of the speed of the vehicle. If the transverse beam <NUM> is subjected to vertical force that is not enough to detach the magnetic means <NUM>, the transverse beam <NUM> stays in its rest position: this vertical force is not due to a derailment.

Usually, the shape of the rod <NUM> and the magnetic means <NUM> are configured to detach if the vertical force is greater than <NUM> daN.

In case the magnetic means <NUM> detach, the transverse beam <NUM> and the rod <NUM> swing anticlockwise.

The detection device <NUM> comprises a contact actuator <NUM> (which can be seen on <FIG>), held by the support <NUM>, and configured to generate an emergency signal when the rod <NUM> meets this contact actuator <NUM>.

Preferentially, the support <NUM> comprises a secondary support <NUM>, the contact actuator being held by this secondary support <NUM>. The secondary support <NUM> is for example fastened to the support bracket <NUM>, under this support bracket <NUM>.

For example, the contact actuator <NUM> comprises a switch <NUM> arranged backward the rod <NUM>, to be actuated when the rods <NUM> meets this switch <NUM> when the rod <NUM> swing anticlockwise.

It should be noticed that the detection device <NUM> could comprise only one contact actuator <NUM>, or in a variant one contact actuator for each rod <NUM>. In this last case, the emergency signal could be generated only when the two switches are actuated, or in a variant when any of the switches is actuated.

The railway vehicle comprises a classical emergency braking system, connected to the contact actuator <NUM> to be able to receive the emergency signal. The emergency braking system is configured to implement an emergency braking operation when receiving the emergency signal.

In a variant, or additionally, the emergency signal could be sent to an alarm system, which emits an alarm when receiving the emergency signal.

Preferentially, the detection device <NUM> comprises a mechanical stop <NUM> arranged on the support <NUM>, intended to limit the swing of the rod <NUM> around the axis. For instance, the mechanical stop <NUM> is arranged on the secondary support <NUM>.

This mechanical stop <NUM> is arranged to stop the swing after the rod <NUM> meets the switch <NUM>. This mechanical stop <NUM> allows preventing the transverse beam <NUM> from coming colliding with the wheels <NUM>, but also from damaging the switch <NUM>.

Claim 1:
An obstacle and derailment detection device (<NUM>) for a railway vehicle extending in a longitudinal direction (X), comprising a transverse beam (<NUM>) intended to be arranged on a front part of the railway vehicle, wherein:
- the detection device (<NUM>) comprises at least one support (<NUM>) intended to be fixed on the railway vehicle, at least one rod (<NUM>) holding the transverse beam (<NUM>), and a pivot connection (<NUM>) around an axis for connecting the rod (<NUM>) to the support (<NUM>), so that the transverse beam (<NUM>) is able to swing around the axis,
- the detection device (<NUM>) comprises a contact actuator (<NUM>), arranged on the support (<NUM>), configured to generate an emergency signal when the rod (<NUM>) comes in contact with this contact actuator (<NUM>)
- the detection device (<NUM>) comprises retaining means (<NUM>) for retaining the transverse beam (<NUM>) in a rest position while not subjected to a force or while subjected to an angular couple inferior to a predefined threshold,
characterized in that the retaining means (<NUM>) comprise at least first (<NUM>) and second (<NUM>) complementary magnetic elements, with the first magnetic (<NUM>) element being arranged on the rod (<NUM>) and the second magnetic element (<NUM>) being arranged on the support (<NUM>).