Electrical connection device with safety fuse element

Abstract

Electrical connection device with safety fuse element The invention relates to an electrical connection device (10), comprising a first (12) and a second (14) electrical connector; the first connector comprising an upper tab (24) and a lower tab (26), the upper tab being arranged above the lower tab; the second connector comprising a central blade (34). In a connection configuration, the central blade (34) of the second connector is arranged between the upper (24) and lower (26) tabs of the first connector and in contact with each of said tabs.The device further comprises: - a reservoir (16) having a lower opening, said reservoir and said opening being arranged above the central blade (34) of the second connector; and - a quantity of solid-state fusible material (18), received in the reservoir above the lower opening, the fusible material being electrically conductive. Figure for the abstract: Figure 1.

Description

Title of the invention: Electrical connection device with safety fuse element

[0001] The present invention relates to an electrical connection device, of the type comprising a first and a second electrical connector; the first connector comprising an upper leg and a lower leg, the upper leg being arranged above the lower leg; the second connector comprising a central blade; the device being configured so that, in a connection configuration, the central blade of the second connector is arranged between the upper and lower legs of the first connector and in contact with each of said legs.

[0002] The invention applies particularly to earthing switch type devices, notably used in the railway sector.

[0003] Such devices are generally limited in terms of the current intensity to be discharged. When currents of excessively high intensity flow through them, said currents induce magnetic repulsion between the two connectors, thus interrupting electrical conduction. An electric arc is then created between the two connectors, which can lead to the destruction of said connectors by melting upon contact with the electric arc.

[0004] In order to solve this problem, the invention relates to an electrical connection device of the aforementioned type, further comprising: a reservoir comprising a lower opening, said reservoir and said opening being arranged above the central blade of the second connector; and a quantity of fusible material in the solid state, received in the reservoir above the lower opening, the fusible material being electrically conductive.

[0005] Such a protective device allows electrical contact to be maintained between the two connectors, even in the event of magnetic repulsion between some of their elements. The destructive electric arc is thus minimized.

[0006] According to other advantageous aspects of the invention, the device comprises one or more of the following characteristics, taken individually or in all technically possible combinations:

[0007] - the tank is secured to the upper leg of the first connector;

[0008] - the fusible material is a metallic material;

[0009] - the metallic material comprises tin.

[0010] The invention further relates to a connection assembly, comprising: a base; an arm movable relative to the base along an axis of rotation; and a flange fixed relative to the base; the assembly further comprising at least one device of electrical connection as described above, the first electrical connector being carried by one of the arm and the flange, the second electrical connector being carried by the other of the arm and the flange; the assembly being configured so that, in an angular position of the arm relative to the base along the axis of rotation, the first and second connectors are assembled to each other in the connection configuration.

[0011] According to one embodiment of the connection assembly, the first electrical connector is carried by the arm and the second electrical connector is carried by the flange.

[0012] According to another embodiment of the connection assembly, the first electrical connector is carried by the flange and the second electrical connector is carried by the arm.

[0013] The invention further relates to a method for implementing a connection device as described above, the method comprising the following steps: assembling the first and second connectors in the connection configuration; circulating an electric current between said first and second connectors; raising the temperature of said first and second connectors under the effect of the electric current; melting the fusible material; flowing the fusible material in the molten state onto the central blade of the second connector and onto the lower leg of the first connector, reinforcing an electrical contact between said central blade and said lower leg.

[0014] Preferably, the flow of the fusible material in the molten state further occurs between the central blade of the second connector and the upper leg of the first connector, reinforcing an electrical contact between said central blade and said upper leg.

[0015] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0016] [Fig. 1][Fig.2] Figures 1 and 2 are schematic views of a device for connection according to an embodiment of the invention, respectively in an initial state and in a final state; and

[0017] [Fig.3] [Fig.3] is a schematic view of a connection assembly comprising the connection device of [Fig.l] in the initial state.

[0018] Figures 1 and 2 show an electrical connection device 10 according to one embodiment of the invention.

[0019] The device 10 comprises: a first 12 and a second 14 electrical connectors; a reservoir 16; and a quantity of fusible material 18.

[0020] In the embodiment shown, the first 12 and second 14 connectors electrical devices are fixed respectively to a first 20 and to a second 22 electrical devices.

[0021] The first connector 12 comprises an upper tab 24 and a lower tab 26, forming a clamp 28. Said clamp 28 extends along a first axis 30. Each of the upper 24 and lower 26 tabs is substantially parallel to the first axis 30 and extends between a fixed end and a free end 32. Each fixed end is secured to the first electrical equipment 20 and electrically connected to said first equipment.

[0022] In the embodiment shown, the first axis 30 is arranged horizontally and the upper leg 24 is arranged above the lower leg 26.

[0023] The second connector 14 comprises a central blade 34. Said central blade 34 extends substantially along a second axis 36, between a fixed end and a free end 38. The fixed end is secured to the second electrical equipment 22 and electrically connected to said second equipment.

[0024] In the embodiment shown, the second axis 36 is arranged horizontally.

[0025] Each of the upper 24 and lower 26 legs and the central blade 34 are formed from electrically conductive materials, such as one or more metals.

[0026] Figures 1 and 2 show the device 10 in a connection configuration.

[0027] In said connection configuration, the first 30 and second 36 axes are sen possibly merged; the free ends 32 of the upper 24 and lower 26 legs of the first connector 12 are oriented towards the second electrical equipment 22; the free end 38 of the central blade 34 of the second connector 14 is oriented towards the first electrical equipment 20; and the central blade 34 of the second connector is arranged between the free ends 32 of the upper 24 and lower 26 legs of the first connector.

[0028] The reservoir 16 comprises a lower opening 40, said opening forming a lower end of said reservoir 16.

[0029] In the connection configuration of Figures 1 and 2, the reservoir 16 and the opening 40 are arranged above the central blade 34 of the second connector 14. Preferably, the opening 40 is arranged substantially vertically to the free end 38 of the central blade 34.

[0030] In the embodiment shown, the reservoir 16 is integral with the upper tab 24 of the first connector 12. Preferably, the reservoir 16 is formed in one piece with the upper tab 24. Said reservoir 16 is arranged between the fixed end and the free end 32 of said upper tab 24, the lower opening opening above the lower tab 26 of the first connector 12.

[0031] The fusible material 18 is electrically conductive. Preferably, the material 18 fuse is a metallic material, with a lower melting temperature than that of the materials forming the legs 24, 26 and the central blade 34. According to one embodiment, said metallic material comprises tin.

[0032] In the initial state of the device 10, shown in [Fig.l], the quantity of fusible material 18 is in the solid state and received in the reservoir 16, above the lower opening 40.

[0033] Furthermore, in the initial state of the device 10, the free end 32 of at least one of the tabs 24, 26 of the first connector 12 is in contact with the central blade 34 of the second connector 14. Preferably, in the initial state of the device 10, the free end 32 of each of the tabs 24, 26 of the first connector 12 is in contact with the central blade 34 of the second connector 14. Thus, an electric current is able to flow between the first 20 and second 22 electrical equipment, via the tabs 24, 26 and the central blade 30.

[0034] In the final state of the device 10, shown in [Fig.2], the quantity of fusible material 18 is spread over the central blade 34 of the second connector 14 and between said central blade 34 and the lower tab 26 of the first connector. The fusible material 18 thus ensures electrical contact between the first 12 and second 14 connectors.

[0035] Preferably, in the final state of the device 10, a portion of the fusible material 18 is also arranged between the central blade 34 of the second connector 14 and the upper tab 24 of the first connector 12, reinforcing the electrical contact between said connectors.

[0036] According to one embodiment, in the final state of the device 10, the free end 32 of at least one of the legs 24, 26 of the first connector 12 is spaced from the central blade 34 of the second connector 14, as will be described below.

[0037] [Fig. 3] shows a connection assembly 50 according to an embodiment of the invention. The assembly 50 comprises an embodiment of the first 20 and second 22 electrical equipment previously described.

[0038] In the embodiment of [Fig. 3], the connection assembly 50 is an earth disconnector and further comprises a base 52.

[0039] The first electrical equipment 20 is integrated into an arm 54, movable in rotation relative to the base 52 around a third axis 56. In the embodiment shown, the third axis 56 is vertical.

[0040] The first electrical equipment 20 is fixed and electrically connected to at least one first connector 12 as described above, the first axis 30 of said first connector 12 being perpendicular to the third axis 56. Preferably, as in the embodiment shown, the arm 54 comprises at least two first connectors 12, fixed and electrically connected to the first electrical equipment 20. Said two first connectors 12 are spaced apart along the third axis 56.

[0041] The second electrical equipment 22 is integrated into a flange 60, fixedly mounted on the base 52.

[0042] The second electrical equipment 22 is fixed and electrically connected to at least one second connector 14 as described above, the second axis 36 of said second connector 14 being perpendicular to the third axis 56. Preferably, as in the embodiment shown, the flange 60 comprises at least two second connectors 14, fixed and electrically connected to the second electrical equipment 22. Said second connectors 14 are spaced apart from each other along the third axis 56.

[0043] The assembly 50 is configured so that, in an angular position of the arm 54 relative to the third axis 56, each of the first connectors 12 of said arm is assembled to one of the second connectors 14 of the flange, in a connection configuration as described above. Each first connector 12 and the corresponding second connector 14 form a connection device 10 as described above.

[0044] Such an angular position of the arm 54, called the closed position, is visible in [Fig. 3]. Furthermore, in [Fig. 3], each device 10 of the connection assembly 50 is in the initial state described above.

[0045] The arm 54 is able to pivot relative to the base 52 around the third axis 56, so as to separate each first connector 12 and the corresponding second connector 14 from each other. An angular position of the arm 54 in which each first connector 12 is separated from the corresponding second connector 14 is called the open position.

[0046] A method of operating the device 10 and the connection assembly 50 will now be described.

[0047] First of all, it is considered that the arm 54 of the assembly 50 is in the open position described above.

[0048] To move from the open position to the closed position, the earthing switch formed by said assembly 50 is actuated. The arm 54 pivots into the closed position, each first connector 12 being assembled to the corresponding second connector 14. At the time of assembly, the connection device 10 formed by each first connector 12 / second connector 14 pair is in the connection configuration and in the initial state of [Fig.l].

[0049] In the event of a slight short circuit in the closed position of the arm 54, the clamp 28 formed by the legs 24, 26 of a first connector 12 remains in contact with the central blade 34 of the corresponding second connector 14. The current is thus discharged to earth via said central blade 30 and said legs 24, 26.

[0050] In the event of a strong short circuit in the closed position of the arm 54, the central blade 34 of the second connector 14 and each of the legs 24, 26 of the first connector 12 ac accumulate electrical charges of the same polarity. The free ends 32 of the legs 24, 26 are repelled by the magnetic field thus generated, moving away from the central blade 34.

[0051] An electric arc then forms between said central blade 34 and the legs 24, 26, leading to an increase in the temperature of the connectors 12, 14.

[0052] Said increase in temperature leads to the melting of the fusible material 18 received in the reservoir 16. Said material 18 in the molten state flows by gravity through the lower opening 40, onto the central blade 34 of the second connector 14 and onto the lower tab 26 of the first connector 12. Even in the event of separation of said lower tab 26 and said central blade 34, the material 18 reestablishes or reinforces an electrical contact between said central blade 34 and said lower tab 26.

[0053] The electric current can again flow between the connectors 12, 14, allowing the short circuit to be discharged to earth. The connectors 12, 14 are thus protected from damage linked to the electric arc.

[0054] Preferably, the flow of the material 18 in the molten state further occurs between the central blade 34 of the second connector and the upper leg 24 of the first connector 12, reestablishing or reinforcing electrical contact between said central blade 34 and said upper leg 24.

[0055] Preferably, the reduction or disappearance of the electric arc leads to a drop in the temperature of the connectors 12, 14 and to the solidification of the material 18 on the central blade 34 and the legs 24, 26. The electrical contact is thus maintained between the connectors 12, 14, until the currents dissipate, allowing a maintenance operation of the assembly 50.

[0056] The connection assembly 50 described above is in particular intended to be installed on the roof of an electric railway vehicle, said roof forming the base 52. An earthing switch formed by such an assembly 50 has improved efficiency compared to known devices.

Claims

1.

2.

3.

4.

5. Claims Electrical connection device (10), comprising a first (12) and a second (14) electrical connectors; the first connector (12) comprising an upper leg (24) and a lower leg (26), the upper leg being arranged above the lower leg; the second connector (14) comprising a central blade (34); the device being configured so that, in a connection configuration, the central blade (34) of the second connector (14) is arranged between the upper (24) and lower (26) legs of the first connector (12) and in contact with each of said legs, the device being characterized in that it further comprises: - a reservoir (16) having a lower opening, said reservoir and said opening being arranged above the central blade (34) of the second connector (14); and - a quantity of solid state fusible material (18), received in the reservoir above the lower opening, the fusible material being electrically conductive. Electrical connection device according to claim 1, in which the reservoir (16) is integral with the upper tab (24) of the first connector (12). Electrical connection device according to claim 1 or 2, wherein the fusible material (18) is a metallic material. An electrical connection device (10) according to claim 3, wherein the metallic material comprises tin. Connection assembly (50) comprising: a base (52); an arm (54) movable relative to the base along an axis (56) of rotation; and a flange (60) fixed relative to the base; the assembly further comprising at least one electrical connection device (10) according to one of the preceding claims, the first electrical connector (12) being carried by one of the arm (54) and the flange (60), the second electrical connector (14) being carried by the other of the arm (54) and the flange (60); the assembly being configured so that, in an angular position of the arm (54) relative to the base along the axis (56) of rotation, the first (12) and second connectors (14) are assembled to each other in the connection configuration.

6. A connection assembly (50) according to claim 5, wherein the first electrical connector (12) is carried by the arm (54) and the second electrical connector (14) is carried by the flange (60).

7. A connection assembly (50) according to claim 5, wherein the first electrical connector (12) is carried by the flange (60) and the second electrical connector (14) is carried by the arm (54).

8. Method for implementing a connection device (10) according to one of claims 1 to 4, comprising the following steps: - assembling the first (12) and second (14) connectors in the connection configuration; - circulating an electric current between said first (12) and second (14) connectors; - raising the temperature of said first (12) and second (14) connectors under the effect of the electric current; - melting the fusible material (18); - flowing the fusible material in the molten state onto the central blade (34) of the second connector (14) and onto the lower tab (26) of the first connector (12), reinforcing an electrical contact between said central blade (34) and said lower tab (26).

9. The method of claim 8, wherein the flow of the fusible material in the molten state further occurs between the central blade (34) of the second connector (14) and the upper leg (24) of the first connector (12), reinforcing an electrical contact between said central blade (34) and said upper leg (24).

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