ASSEMBLY OF A HEADLIGHT AND A CONNECTOR

Abstract: The assembly of a headlight (1) and a connector (2) has in the headlight (1) an electric discharge lamp (3) with a lamp cap (4) and contacts (6) at this lamp cap, which cap is attached by a fixing member (10) to a reflector (7). The headlight (1) has beside the lamp cap (4) a contact member (13). The connector (2) has main contacts (11) for the lamp (3) and additional contacts (12) adapted to cooperate with the contact member (13). It is not until the contact member (13) interconnects the additional contacts (12) that a high voltage is applied across the main contacts (11) of the connector (2).

Description: The invention relates to an assembly of a headlight and a connector, in which the headlight comprises: an electric discharge lamp provided with a lamp cap and electrical conductors, which extend from the lamp to contacts at the lamp cap, a reflector provided with an opening for receiving the lamp cap of the lamp and with fixing means arranged to surround this opening, a fixing member for fixing the lamp cap in the opening of the reflector, which fixing member is adapted to cooperate with the fixing means of the reflector, and the connector has main contacts for connecting the discharge lamp to a lamp circuit when the main contacts of the connector are arranged against the contacts at the lamp cap. A headlight for such an assembly is known from EP-A1-152649. The electric discharge lamp used in the headlight lamp requires a high voltage of several kV to ignite and to produce rapidly a considerable quantity of light. It is dangerous when bare metal parts of the lamp are touched when they are applied to this high voltage. These parts could be touched if the lamp is connected via the connector to its voltage source before the lamp is arranged in the reflector. It may also be dangerous when the connector is applied to a high voltage, while it is detached from the contacts at the lamp cap, for example when the lamp is exchanged. US-A-4 044 208 describes two-part electrical connectors, a first one of which comprises a switch in a low voltage circuit. The switch is closed upon the insertion of the second part into the first one, thereby activating a switching device which connects the connectors to a power source. US-A-4 456 857 describes a lamp holder incorporating a switch which is operated by a lamp inserted into the holder, thereby connecting the holder to a power supply. When the second part of the known two-part connectors and when the lamp inserted into the known lamp holder have bare alive metal parts, as it is the case when in the headlight of the cited EP-A1-153 649 the discharge lamp is united with a connector outside the reflector, said second part and said lamp are unsafe. The invention has for its object to provide an assembly of the kind described in the opening paragraph, in which the risk of touching alive bare metal parts is obviated. According to the invention, this object is achieved in said assembly in that the connector has additional contacts adapted to be included in a low-voltage circuit feeding the lamp circuit and the headlight has beside the lamp cap a contact member which electrically interconnects the additional contacts of the connector only when the main contacts of the connector are arranged against the contacts at the lamp cap and the cap has been fixed in the reflector by bringing the fixing member into its final position at the reflector by more than a translation. In the assembly according to the invention, the reflector or the fixing member can have a contact member which closes, in a vehicle, when the connector is arranged, an electrical circuit of low voltage, for example 12 V, as a result of which the lamp circuit of high voltage, for example 10 kV, is excited. Another possibility consists in that the reflector and the fixing member each have a complementary part of this contact member. When the connector is detached from the headlight, the current supply to the feeding apparatus of the headlight is therefore interrupted. From a view point of construction, a contact member at the reflector or at the fixing member is to be preferred. Of these two possibilities, that of providing a contact member at the fixing member is easiest to realize. In the assembly according to the invention, it is not possible to supply the discharge lamp outside the reflector with a high voltage by placing the connector on the contacts of the lamp cap if the additional contacts are not intentionally interconnected by artificial means. The possibility of touching accidentally a bare conductor carrying high voltage, i.e. either a conductor of the discharge lamp or a main contact of the connector, is thus effectively obviated. The additional contacts of the connector can form part of a switch which is closed by the contact member. The contact member can then itself be an electrical isolator. In an attractive embodiment, however, the additional contacts are electrically interconnected by an electrically conducting contact member. The contact member is then electrically included in the circuit of which these additional contacts form part. The additional contacts may be arranged, for example, opposite to each other in the proximity one of the other so that they may be interconnected, for example, by one strip, pin or sleeve. Another possibility consists in that they are arranged at a greater relative distance so as to be spatially separated and each come into contact with their own, for example strip-, pin- or sleeve-shaped contact part of the contact member. Since a loose connector may carry a low voltage, the additional contacts are preferably arranged so as to be sunk into the connector, in the embodiment last described, for example in an individual cavity. The assembly can be used in vehicles. The headlight of the assembly can be suitable for producing a high beam or a dipped beam or for use as a fog-lamp. The electric discharge lamp used may then be, for example, a high-pressure sodium discharge lamp or a high-pressure mercury discharge lamp with metal halide additions or a high-pressure xenon discharge lamp, as the case may be with halide additions. The contacts at the lamp cap and the contact member may extend in the longitudinal direction of the reflector, as it is shown in the drawings, or in a direction cross thereto. In the last event less space longitudinally of the reflector is needed by the connector. Embodiments of the assembly according to the invention are shown in the drawings. In the drawings: Figure 1 is a longitudinal sectional view of a first embodiment of an assembly, Figure 2 is a front elevation of a connector for a second embodiment in an electric circuit, Figure 3 is a side elevation of the second embodiment of an assembly, in which the connector is shown partly broken away and partly in longitudinal sectional view. In Figure 1, the assembly of headlight and connector comprises a headlight 1 and a connector 2. The headlight 1 comprises an electric discharge lamp 3 provided with a lamp cap 4 and electrical conductors 5, which extend from the lamp 3 to contacts 6 at the lamp cap 4. The headlight 1 further comprises a reflector 7 provided with an opening 8 for receiving the lamp cap 4 of the lamp 3 and with fixing means 9 around this opening 8. The fixing means 9 are an integral part of the reflector 7 in the embodiment shown. The headlight further comprises a fixing member 10 for fixing the lamp cap 4 in the opening 8 of the reflector 7. The fixing member 10 is adapted to cooperate with the fixing means 9 of the reflector 7. In the embodiment shown, the fixing member is a union nut which is arranged axially around the fixing means 9 and the lamp cap 4 and is then rotated through an angle of several degrees to an abutment stop to cooperate with the fixing means 9. The connector 2 has main contacts 11 for connection of the discharge lamp 3 to a lamp circuit when the main contacts 11 of the connector 2 are arranged against the contacts 6 at the lamp cap 4. The connector 2 has additional contacts 12 adapted to be included in a low-voltage circuit feeding the lamp circuit. The headlight 1 has beside the lamp cap 4 a contact member 13, which electrically interconnects the additional contacts 12 of the connector 2 when the main contacts 11 of the connector 2 are arranged against the contacts 6 of the lamp cap 4. In the embodiments shown, the contact member 13 comprises two contact parts 14 in the form of metal strips, which are interconnected by means of a metal annular disk 15. The contact member 13 is therefore electrically conducting and is electrically included in the circuit through the additional contacts 12. The contact member 13 has an individual contact part 14 for each additional contact 12 of the connector 2. The contact member 13 is present in the fixing member 10. When the assembly 1 is mounted, the electrical discharge lamp 3 is introduced through the opening 8 inside the reflector 7 so that the opening 8 receives the lamp cap 4. The fixing member 10 is then provided, this member first performing a translation to the reflector 7 and the lamp cap 4 and then a rotation, cams 16 then engaging behind the fixing means 9. It is not until then that the contacts 6 at the lamp cap 4 and the contact strips 14 of the contact member 13 in the fixing member 10 are in a configuration corresponding to the configuration of the main contacts 11 and the additional contacts 12 of the connector 2. When the connector 2 is placed on the headlight 1, the contacts 6 at the lamp cap 4 are simultaneously connected to a lamp circuit and the additional contacts 12 of the connector 2 are interconnected so that a low-voltage circuit is closed which feeds the lamp circuit. When the contact member 13 does not engage into the connector 2, the main contacts 11 and hence the discharge lamp 3 do not carry a high voltage. An attractive property of the assembly shown is that an electric switch with movable parts is present neither in the connector 2 nor at the headlight 1. A small elastic deformation of the main contacts 11 and the additional contacts 12 when they are in contact with the contacts 6 and with the contact member 13, respectively, is left out of consideration here. It is also favourable that the additional contacts 12 are arranged in an individual cavity 17 in the connector 2 so as to be spatially separated from each other. Washers are designated by reference numeral 18. Figure 2 shows a connector 22 in front elevation, as well as a voltage source 19 and a high-voltage supply apparatus 20. The high-voltage supply apparatus 20 is included together with the voltage source 19 in a low-voltage circuit 39, which is opened due to the fact that additional contacts 32 of the connector 22 are not interconnected. It is not until the additional contacts 32 are interconnected by means of a contact member 33 (Figure 3) that the high-voltage supply apparatus 20 is excited and a high voltage is applied across the main contacts 31 of the connector 22 which are included together with the lamp 3 in a lamp circuit 40. It appears from Figure 3 that the additional contacts 32 are interconnected by means of the contact member 33, which is present at the reflector 27, at the instant at which the connector 22 is placed on the lamp cap 24. The contact member 33 is then connected electrically in series with the additional contacts 32, just like the contact member 13 with the additional contacts 12 in Figure 1. The lamp cap 24 has a contact 26 and is held in the reflector 27 by a fixing member 30. The lamp cap 24, the reflector 27 and the fixing member 30 form part of a headlight 21.

Claims: An assembly of a headlight (1) and a connector (2), in which the headlight (1) comprises: an electric discharge lamp (3) provided with a lamp cap (4) and electrical conductors (5), which extend from the lamp (3) to contacts (6) at the lamp cap (4); a reflector (7) provided with an opening (8) for receiving the lamp cap (4) of the lamp (3) and with fixing means (9) arranged to surround this opening (8); a fixing member (10) for fixing the lamp cap (4) in the opening (8) of the reflector (7), which fixing member (10) is adapted to cooperate with the fixing means (9) of the reflector (7), and the connector (2) has main contacts (11) for connecting the discharge lamp (3) to a lamp circuit when the main contacts (11) of the connector (2) are arranged against the contacts (6) at the lamp cap (4), characterized in that the connector (2) has additional contacts (12) adapted to be included in a low-voltage circuit feeding the lamp circuit, while the headlight (1) has beside the lamp cap (4) a contact member (13) which electrically interconnects the additional contacts (12) of the connector (2) only when the main contacts (11) of the connector (2) are arranged against the contacts (6) at the lamp cap (4) and the cap (4) has been fixed in the reflector (7) by bringing the fixing member (10) into its final position at the reflector by more than a translation. An assembly as claimed in Claim 1, characterized in that the contact member (13) is present at the fixing member (10). An assembly as claimed in Claim 1, characterized in that the contact member (33) is present at the reflector (27). An assembly as claimed in Claim 2 or 3, characterized in that the contact member (13) is electrically conducting and is electrically connected in the circuit by the additional contacts (12) in series therewith. An assembly as claimed in Claim 4, characterized in that the contact member (13) has an individual contact part (14) for each additional contact (12) of the connector (2). An assembly as claimed in Claim 5, characterized in that the additional contacts (12) are each sunk into an individual cavity (17) in the connector (2).

Inventors: RIJCKAERT, JOSEPHUS FRANCISCUS, VAN HEESWIJK, JOHANNES A. A. M.
Applicants: N.V. PHILIPS' GLOEILAMPENFABRIEKEN
Application year: 1988
Main classification: F21M7
IPC codes: F21V25, H01R33, F21V17, F21V19, F21S8, F21V23