Dual-contact contactor and arc blowout chimney
The present invention relates to a contactor, of the type comprising:
- an insulating body comprising:
- at least a first contact which is fixed relative to the body;
- at least a second contact which is fixed relative to the body;
the contactor comprising at least one movable item of equipment which can be moved relative to the first and the second fixed contacts and which has a first and a second movable contact which are capable of selectively being brought into contact with the first fixed contact and the second fixed contact, respectively.

Contactors are used for the insulation and reconfiguration of high-voltage power networks for supplying electrical power to trains. These contactors are used in particular to supply or to place at a reference potential the successive portions of supply rails, so that the rail portions are supplied with electrical power only when they are covered by the tramway in order to prevent passers-by from potentially being electrocuted.

A given number of contactors are known, such as those described in documents FR 2 287 765 and FR 2 308 188.

It is known that, when an electrical circuit is opened under voltage, an electric arc can be created between the contacts which move apart from each other.
When the contactor comprises at least two fixed contacts and two movable contacts which are carried by a movable item of equipment which can be moved between the first and second fixed contacts, it is proposed in the above-mentioned documents to insulate the corresponding pairs of fixed contacts and movable contacts, in order to prevent a possible electric arc from propagating towards another pair of contacts. In this manner, the pairs of electrical contacts are insulated in chambers which are also as far apart as possible, in particular by distributing the pairs of contacts in two directions which are perpendicular relative to each other.

An object of the invention is to allow better blowout of the arc in a contactor having a plurality of movable contacts.

To this end, the invention relates to a contactor of the above-mentioned type, characterized in that the body is provided with an arc blowout chimney which is common to the first and second pairs of fixed contacts and movable contacts, the first and second fixed contacts and the first and second movable contacts being arranged in the same chamber opposite the base of the common chimney.

According to specific embodiments, the contactor comprises one or more of the following features:

- it comprises a third and a fourth fixed contact and the movable equipment comprises a third and a fourth movable contact which are capable of selectively being brought into contact with the third and the fourth fixed contacts, respectively, the first and the third movable contacts are electrically connected in order to form a first connection bridge and the second and fourth movable contacts are electrically connected in order to form a second connection bridge, the body is provided with a second arc blowout chimney common to the third and fourth pairs of fixed contacts and movable contacts, the third and fourth fixed contacts and the third and fourth movable contacts being arranged in the same chamber opposite the base of the second common chimney,
- the first and second movable contacts are electrically connected to each other,
- the chimney comprises arc cut-off plates which are arranged transversely along the axis of the chimney;
- the movable equipment can be moved in translation and the chimney extends transversely relative to the translation movement axis of the movable equipment.
The invention will be better understood from a reading of the following description, given purely by way of example and with reference to the drawings, in which:
- Figure 1 is a schematic longitudinal section of a contactor according to the invention, the contactor being in the idle state;
- Figure 2 is a view identical to that of Figure 1, the contactor being in an activated state; and
- Figures 3 and 4 are detailed views of Figures 1 and 2 illustrating the propagation and the blowout of an arc formed between the contacts during the pivoting of the contactor towards the state thereof in Figures 1 and 2, respectively.

The contactor 10 illustrated in Figure 1 comprises, in a casing 11, a connection module 12 and an actuator 14 which is capable of controlling the commutation of the connection module 12 from a first state to a second state.

The connection module 12 comprises a first and a second input terminal 16, 18 which are capable of being connected to electrical cables which are not illustrated. Each terminal is fixedly joined to a first and second fixed contact 20, 22, respectively.

In the same manner, output terminals 24, 26 are arranged symmetrically relative to the input terminals 16, 18 relative to the axis of symmetry X-X of the contactor. The two terminals 24, 26 comprise third and fourth fixed contacts 28, 30, respectively. These contacts are symmetrical relative to the first and second contacts 20 and 22 relative to the axis X-X, respectively. In this manner, the contacts 20, 2 8 and 22, 30 are coplanar.

A movable item of equipment 32 is mounted so as to be able to slide along the axis X-X between the fixed contacts 20, 2 8 on the one hand and 22, 30 on the other hand under the control of the actuator 14.

The item of movable equipment 32 comprises an insulating body 34 which carries a conductive plate 36 which is mounted so as to be able to slide relative to the body 34. The body 34 comprises a main rod 38 which extends along the axis X-X and which is mounted so as be able to slide along this axis.

At the end thereof directed towards the actuator 14, the rod 34 has a transverse stop surface 40 which is capable of limiting the movement of the plate 36 towards the terminals 18 and 26 which are fixedly joined to the casing and to ensure movement of the plate 36 towards the fixed contacts 20, 28 when the movable equipment moves these same contacts.

At the other end thereof, the rod 38 comprises a collar 42 for abutment of a helical spring 44 which is interposed between the collar 42 and the plate 36. The spring 44 is capable of resiliently urging the plate 36 against the stop 40.

The plate 36 comprises a conductive bar 46 which extends transversely relative to the rod 38. The bar has a centre hole through which the rod 38 is fitted so that the bar slides along the rod 38 between the two stops 42 and 40 whilst being retained by the spring 44. The bar 46 can be moved between the planes defined by the first and third fixed contacts 20, 28 and the second and fourth fixed contacts 22, 30, respectively.

Opposite these fixed contacts, the plate 36 has, at the ends of the bar 46, first, second, third and fourth movable contacts designated 50, 52 and 58, 60, respectively.

The movable contacts 50, 52, 58, 60 are electrically connected to the conductive bar 46 and are capable of moving into abutment against opposing fixed contacts 20, 22, 28 and 30 and thereby providing an electrical connection between them.

The actuator 14 comprises an electromagnet 62 which comprises a winding 64 surrounded by a frame 66, both of which are fixed in position in the casing 11 of the contactor.

The winding and the frame are centered in accordance with the axis X-X. The electromagnet 62 comprises a magnetic core 68 which is mounted so as to slide along the axis X-X inside the frame 66 and the winding 64.

The core 68 is fixedly joined to a shaft 70 which is connected axially to the rod 38 of the movable equipment 32. A return spring 72 is arranged between the movable equipment and the frame 66 in order to urge the movable equipment 32 away from the actuator, that is to say, into a position in which the conductive plate 36 is in contact with the first and third fixed contacts. More precisely, the spring 72 is held in a compressed state between the frame 66 and a collar 73 which forms a stop and is provided on the rod 38.

The winding 64 is connected via a control circuit to an appropriate source of voltage 74 via a commentator 76.

As illustrated in Figure 1, the first and the second pairs of opposing movable and fixed contacts arranged at the same side of the bar 46 are contained in the same chamber which opens outwards via a chimney 80 common to the two pairs of contacts. In this manner, two opposing chimneys are formed.

Each chimney begins in the region of a pair of movable and fixed contacts. In this manner, two fixed contacts 20, 22 or 28, 30 and two movable contacts 50, 52 or 58, 60 are located opposite the chimney.

Each chimney generally extends radically relative to the direction X-X. It has plates 82 for fragmenting an electric arc which extend substantially parallel with each other and which are directed in accordance with the axis of the chimney.

The contactor operates in the following manner.

In the idle state and as illustrated in Figure 1, the switch 76 is open so that the electromagnet does not act on the movable equipment 32. Under these conditions, the spring 72 retains the movable equipment so that the stop 40 is in abutment against the plate 36 which is itself in abutment against the output terminal 24 and the input terminal 16. The terminals 18 and 26. In this position, the spring 44 is compressed. The first and third terminals 16, 24 are thus associated. Under these conditions, a first contact bridge is established between the first and third movable contacts 50, 58 which are themselves pressed against the first and third fixed contacts 20, 28.

When the switch 76 is closed, and as illustrated in Figure 2, the core 68 is returned inside the windings so as to compress the spring 72. The movable equipment is moved towards the electromagnet and the plate 36 is pressed against the second and fourth fixed contacts 22, 30, the stop 40 being removed, moving forward so that the plate 36 is no longer in abutment against the stop 40. In this position, the plate 36 is held pressed by the spring 44 in a compressed state between the plate 36 and the collar 42. In this instance, the plate 36 forms a second contact bridge between the second and fourth movable contacts 52, 60 which are themselves pressed against the second and fourth fixed contacts 22, 30.

When the movable equipment moves towards the position illustrated in Figure 1, or towards the position illustrated in Figure 2, an electric arc is produced between the fixed and movable contacts which are initially in contact, as illustrated in Figures 3 and 4, respectively. This electric arc spreads radially away from the contacts which are initially in contact and propagates in the chimney.

When the electric arc reaches the cut-off plates 82, the electric arc breaks into a plurality of successive segments, thus promoting the blowout thereof.

It should be noted that, since the same chimney is used for the cut-off and blowout of the arc created by one or other of the pairs of movable and fixed contacts arranged opposite the chimney, it is possible to dispense with the use of two additional chimneys.

CLAIMS

1. Contactor (10) comprising:
- an insulating body (11) comprising:
- at least a first contact (20) which is fixed relative to the body (11);
- at least a second contact (22) which is fixed relative to the body (11),
the contactor comprising at least one movable item of equipment (32) which can be moved relative, to the first and the second fixed contacts (20, 22) and which has a first and a second movable contact (50, 52) which are capable of selectively being brought into contact with the first fixed contact (20) and the second fixed contact (22), respectively, characterised in that the body (11) is provided with an arc blowout chimney (80) which is common to the first and second pairs of fixed contacts (20, 22) and movable contacts (50, 52), the first and second fixed contacts (20, 22) and the first and second movable contacts (50, 52) being arranged in the same chamber opposite the base of the common chimney (80).

2. Contactor according to claim 1, characterised in that it comprises a third and a fourth fixed contact (28, 30) and the movable equipment (32) comprises a third and a fourth movable contact (58, 60) which are capable of selectively being brought into contact with the third and the fourth fixed contacts (28, 30), respectively, in that the first and the third movable contacts (50, 58) are electrically connected in order to form a first connection bridge and the second and fourth movable contacts (52, 60) are electrically connected in order to form a second connection bridge, and in that the body (11) is provided with a second arc blowout chimney (80) common to the third and fourth pairs of fixed contacts (28, 30) and movable contacts (58, 60), the third and fourth fixed contacts and the third and fourth movable contacts (58, 60) being arranged in the same chamber opposite the base of the second common chimney (80).

3. Contactor according to claim 1 or claim 2, characterised in that the first and second movable contacts (50, 52) are electrically connected to each other.

4. Contactor according to any one of the preceding claims, characterised in that the chimney (80) comprises arc cut-off plates (82) which are arranged along the axis of the chimney (80).

5. Contactor according to any one of the preceding claims, characterised in that the movable equipment (32) can be moved in translation and the chimney (80) extends transversely relative to the translation movement axis of the movable equipment (32).