Hybrid socket with locking function for single-filament or dual-filament bulb

The present invention relates to a hybrid socket for a single-filament or dual-filament bulb consisting of a body made of an insulating material, exhibiting a front cavity for introducing the bulb, of substantially rectangular shape, complementary to the exterior shape of the base. It comprises at least one stopper of complementary cross section to that of the cavity of circular cross section, each traversed by a supply wire crimped onto a metallic contact of a first type, and a third stopper of complementary cross section to that of the cavity of oblong cross section, crimped onto an earth metallic contact. The socket furthermore comprises a locking hook for the bulb. Application: socket for type T20 blinking indicator lights or side lights.

BACKGROUND

Field of the Invention

The present invention relates to the field of electrical connection equipment, and more particularly to electrical connectors and sockets.

It relates in particular to the field of electrical sockets in the automobile field, especially the sockets for a mixed use for type T20 single-filament or dual-filament bulbs with W3×16D W3×16q, WY3×16q and W×3×16d type bases for example. These bulbs are used in particular for the rear and front directional signals and side light bulbs, brake lights, back-up lights and side repeater. They are also intended for daytime signalling of vehicles, since such bulbs are particularly resistant to high temperatures.

These lamps consist of a glass bulb traversed by metallic wires extending the legs supporting the filament(s). Such bulbs exhibit no metallic base or additional portion. The linking area between the base of a substantially rectangular cross section and the bubble exhibits a shoulder intended for the engagement of the bulb into the socket. The base also exhibits a foolproofing protrusion, the height and width of which are defined by the nature of the bulb (dual-filament or single-filament).

Waterproof sockets are known in the prior art, which consist of a base exhibiting a single cavity for the passage of the supply wires. These supply wires traverse a single sealing stopper at three separate holes. The single stopper is then forced into the cavity to seal the socket.

The disadvantage of these sockets of the prior art is that assembling the wires requires an operation, which cannot be automated but with difficulty, consisting of first preparing the sealing stopper. This step of manual preparation consists in inserting the free end of each wire, crimped onto the corresponding contact, into one of the holes of the stopper provided for this purpose. Then, the contacts are positioned in the socket, before the introduction of the stopper.

The free end is then crimped to complete the assembly.

These sockets of the prior art are not suitable for an advanced automation of manufacture, which results in high production costs.

Sockets were also provided in the prior art, the rear end of which was open to enable the manual assembling of the supply wires and the contacts. The cavity was then filled with a resin embedding the supply wires and filling the cavity provided for the introduction of the contacts.

This solution is not totally satisfactory because it involves an operation, consisting in adding resin, executed by a special machine. In addition, under certain conditions, a lifting of the resin from to the cavity formed in the socket has been observed, which might result in loss of tightness.

The patent application PCT WO2011/0280053 is more particularly known in the state of the art, which describes a bulb socket, optimized to improve the earthing (grounding) performances, in spite of the vibrations taken during use. The bulb comprises a connector projecting from a lower end of the light emitting element, and has, at each of a front surface and a rear surface thereof, a pair of parallel resilient terminals. The socket comprises a resilient support terminal unit positioned at an inner wall surface of a coupling cavity defined within the socket and used for resiliently supporting the connector inserted in the coupling cavity while producing an electrical connection with the electrical terminals. Any one of each pair of electrical terminals is pressed and supported by the resilient support terminal unit at a height different from that of the adjacent electrical terminal positioned on the same surface of the connector and the other electrical terminals positioned on the opposite surface of the connector.

SUMMARY

To overcome the disadvantages of the prior art, the invention, in its broadest sense, relates to a hybrid socket for a single-filament or dual-filament bulb consisting of a bubble made of glass extended by a base made of glass and exhibiting at least one pair of wires traversing the base and each one folded over one face of the base to form a metallic contact parallel to the longitudinal axis of the bulb. The socket consists of a body made of an insulating material, exhibiting a front cavity for introducing the bulb of substantially rectangular shape complementary to the exterior shape of the base. The insulating body exhibits fastening means on a reflector and a flange for receiving a seal providing tightness with the reflector.

The cavity exhibits a longitudinal groove for engagement of a locking hook with the bulb. The rear portion of said body exhibits at least one longitudinal cavity of circular cross section and a longitudinal cavity of oblong cross section. The socket furthermore comprises at least one stopper of complementary cross section to that of the cavity of circular cross section, each one of said stoppers being traversed by a supply wire crimped onto a metallic contact of a first type and a third stopper of complementary cross section to that of the cavity of oblong cross section, crimped onto an earth metallic contact.

The contacts of the first type consist of a metallic leaf spring folded and cut to form at least one current pick-up pad and a locking hook.

The earth contact consists of a metallic leaf spring folded and cut to form at least one current pick-up pad and a locking hook adapted to engage with a first shoulder of the bulb. The socket furthermore consists of a locking hook consisting of a metallic leaf spring folded and cut to enable the insertion thereof through the front face of the insulating body, with said locking hook being adapted to engage with a second shoulder of the bulb9, arranged on the opposite face of the base, relative to said first shoulder.

The invention differs from the prior art more particularly in the following characteristics:each contact of the first type consists of a metallic leaf spring folded and cut to form a current pick-up pad, and a locking pawl;the earth contact consists of a metallic leaf spring folded and cut to form at least one current pick-up pad and a locking hook adapted to engage with a first shoulder of the bulb;the cavity exhibits a longitudinal groove for engaging a locking hook for the bulb; andthe socket furthermore comprises a locking hook consisting of a metallic leaf spring folded and cut to enable the insertion thereof through the front face of the insulating body, said locking hook being adapted to engage with a second shoulder of the bulb, arranged on the opposite face of the base, relative to said first shoulder.

According to a first alternative solution, said earth contact consists of a metallic leaf spring folded and cut to form a single laterally offset current pick-up pad, and a locking hook adapted to engage with a first shoulder of the bulb, the socket furthermore comprising a solid wall to seal one of the cavities of circular cross section, for use with a single-filament bulb.

According to a second alternative solution, said earth contact is formed by a metallic leaf spring folded and cut to form two current pick-up pads, offset laterally on either side of the median and a locking hook adapted to engage with a first shoulder of the bulb for use with a dual-filament bulb.

Advantageously, the oblong cavity exhibits two longitudinal guide wings to ensure the correct positioning of the earth contact.

Preferably, the circular cavities exhibit two longitudinal guide wings to ensure the correct positioning of the contacts of the first type.

According to a particular embodiment, said front cavity for inserting the bulb exhibits lateral guide zones arranged longitudinally to ensure the guiding of the shorter sides of the bulb base.

According to another alternative solution, said front cavity for introducing the bulb, exhibits adjustment protrusions positioned to come into contact with the electrical contacts of the bulb.

DETAILED DESCRIPTION

FIGS. 1 and 2show exploded views of a socket, according to the invention, respectively for use with a T20 single-filament bulb, and for use with a T20 dual-filament bulb.

The socket according to the invention is characterized in that the same body enables use for both bulbs, without any modification of the insulating body, except for the closing or not of one of the rear cavities. This enables a reduction in the mould designing and manufacturing costs. The mould can be adapted by adding or removing a matching part.

The assembly described inFIGS. 1 and 2first comprises a bulb1of the T20 type exhibiting a bubble2extended by a base3. This assembly, consisting of the bubble2and the base3, forms a single moulded piece made of glass. The base3is traversed by metallic extensions of the filament supports, respectively an earth (ground) electrical contact4and a supply electrical contact5of the first filament, and for dual-filament bulbs, a second earth (ground) electrical contact6and a second supply electrical contact7of the first filament. The base exhibits on either side a shoulder8for adjusting the bulb in a socket.

The assembly also includes a socket consisting of:an insulating body10one or two supply means11,12a means13for connection to earth (ground).

The insulating body10is a part moulded in plastic, for example polybutylene terephtalate (PBT) with a load of about 30% by weight of glass fibres, or of 4.6 type polyamide.

It exhibits a front zone14of a substantially tubular shape, provided at its exterior surface with locking pins15,16and a foolproofing pin17specific to the type of bulb (single- or dual-filament). Such tubular portion14is extended by a flange18whereon a seal providing tightness with the reflector is placed, when the socket is mounted onto the reflector.

The rear portion of the insulating body10exhibits three longitudinally oriented cavities19,20,21.

The first two cavities19,20are intended for the passage of the supply wire of the two filaments (for the dual-filament application). For the single-filament application, one of the cavities20is closed by a wall formed during the moulding of the part. For the bi-filament applications, the insert forming the wall is removed from the mould to form a through cavity.

The third cavity21exhibits an oblong cross section. It is intended for the passage of the earth contact24.

Finally, the socket comprises one or two supply contacts22,23and an earth contact24crimped onto supply wires respectively25,26and27. Each of the wires25to27is respectively engaged in a stopper28to30.

The stoppers28,29intended for the supply wires25, are standard cylindrical stoppers exhibiting deformable peripheral lips for sealingly fitting to the inner surface of the receiving cavity.

The stopper30for the earth wire27is a specific stopper, of a substantially parallelepiped shape, also exhibiting the deformable peripheral lips for sealingly fitting to the inner surface of the receiving cavity.

Finally, the socket comprises a metallic locking hook31, completing the adjustment of the base3with respect to the insulating body.

FIG. 3shows a detailed view of the earth (ground) contact24crimped onto the electrical wire27inserted into the stopper30.

This earth contact (electrical ground contact) consists of a metallic leaf, for example made of bronze, cut and folded to exhibit a crimping zone32extended by a rectangular guide zone33. This guide zone33exhibits, on both sides, wings34,35engaging with a complementary receiving zone formed in the cavity21of the hollow body. The guide zone33exhibits a locking pawl47which ensures the locking of the contact in the insulating body.

This guide zone33is extended by two side tabs36,37and a curved central tab38.

The lateral tabs36,37form pads39,40adapted to ensure an electrical connection with the bulb earth (ground) contacts4and6. In the case of a single-filament application, the tab36is removed.

The central tab38is folded without bending at about 175°, unlike the side tabs36,37. The central tab38exhibits a tile-shaped deformation with a cross shoulder41adapted to perform a hooking (latch) with the cross surface of the shoulder8of the lamp bulb. This tile-shaped deformation ends in a cross zone42positioned under the front surface of the cavity of the hollow body to prevent snagging of the tab upon insertion of the bulb.

The stopper30exhibits a hole43provided in its inner surface with lips which sealingly fit to the exterior surface of the earth wire27.

FIG. 4shows a detailed view of the supply contact22crimped onto the electrical wire25inserted into the stopper28.

This earth contact consists of a metallic leaf, for example made of bronze, cut and folded to exhibit a crimping zone44extended by a rectangular guide zone45. This guide zone45exhibits a locking pawl46which ensures the locking of the contact in the insulating body. The guide zone45is extended by a portion curved at about 175° to form a pad48adapted to ensure an electrical connection with the electrical contact5or7of the bulb.

FIGS. 5 and 6respectively show a detailed view of the locking hook and a view of the hollow body provided for receiving the locking hook.

The locking hook is folded and cut in a metallic sheet, or possibly another resiliently deformable material.

It exhibits a guide zone49of a substantially rectangular shape, with two side wings50,51engaging with complementary guide rails provided in the cavity of the insulating body. A locking pawl52holds the hook when it is correctly engaged in the insulating body. This guide zone49extends into a zone53folded inwards, terminating with a cross shoulder54adapted to (latch) perform a hooking with the cross surface of the shoulder9of the bulb base, and thus to complete the locking provided by the earth (ground) contact.

The shoulder54exhibits two side tabs55,56engaging into a cavity provided at the end of the receiving groove57provided in the insulating body. Such receiving zone opens into the cavity58provided for the engagement of the base3of the bulb1.

The movable slide60consists of a hollow portion exhibiting two lateral flanks61,62connected by an upper surface63liable to cover the upper surface of the body10.

The lateral flanks61,62exhibit, on the inner surfaces thereof, a rib the width of which corresponds to the thickness of the rails64provided on the side faces of the body10to provide guiding in translation.

In the example described, the guiding direction is perpendicular to the axis of insertion of the supply means11,12,13. But the guiding direction could be inclined with respect to these axes in alternative embodiments.

The side flanks exhibit, at the front portions thereof, hooks67,68perpendicular to the direction of translation of the slide60.

These hooks form a retaining means engaging with complementary hooks65,66provided on the body10. These hooks65,66and67,68are respectively so configured as to limit the rearward travel of the slide3and to prevent the withdrawal thereof from the body10.

The hooks65,66formed on the slide60exhibit a bevel directed frontward, to enable the forcing and ensure the wickering and locking of the slide60on the body10. In this locked position, the slide60prevents removal of the supply means11,12,13.

Moreover, when the supply means11,12,13are not correctly engaged in the body10, the slide cannot be engaged in the locked position, which avoids any risk of imperfect assembling of the socket.

FIGS. 7 and 8show three-quarter rear views of a socket according to an alternative solution enabling to achieve a side (FIG. 7) or axial (FIG. 8) outlet for the wires. For this purpose, the slide60exhibits a cavity100opening on the one hand onto the rear face101of the slide, and on the other hand onto a side cut102.

When an axial outlet is desired, the wires go out of the slide through the opening100provided in the slide without being folded.

When a side outlet is desired, the wires are folded prior to the engagement of the slide60, to go out through the cut102.