TECHNICAL FIELD

The present invention relates to an incandescent light-bulb socket.

More in detail, the present invention relates to a long-life incandescent light-bulb socket of the type usually used in manufacturing of front or rear lights of motor vehicles, motorcycles and the like; use to which the following description will explicitly refer however without this implying any loss of generality.

The present invention further relates to an automotive light comprising such a light-bulb socket.

BACKGROUND ART

As known, front and/or rear car lights are increasingly often recessed into the vehicle body, within seats that are difficult to reach/access from within the body for the usual ordinary maintenance operations, such as for example the light-bulb replacement .

In order to obviate this drawback, some car manufacturers have resolved to use automotive lights provided with special long-life incandescent light-bulbs (such as for example the incandescent light-bulbs has recently marketed by Philips with the name "HiPerVision" ) which, the light flow produced being equal, ensure a nominal life time that is almost ten times higher than that of the traditional filament light-bulbs with bayonet coupling. Such a device allows the light maintenance operations to be minimized.

These special light-bulbs comply with E.C.E. R37 standards, and are provided with a glass bulb having a substantially spherical-ampoule shape which houses the incandescent filament of the light-bulb; and with a plastic-material connection plug which is arranged to close the neck of the glass bulb and is structured so as to be forcedly inserted/fitted within a special coupling seat made in the socket.

More in detail, . the plastic-material plug is provided with a headpiece which houses the terminals of the two rheophores which conduct the electric current up to the filament placed within the glass bulb, and is shaped so as to mesh/penetrate into the coupling seat for arranging the terminals of the two rheophores in direct contact with the electricity supply clamps at the bottom of the coupling seat; and with a peripheral stabilizing flange which overhangly protrudes from the plug body, between the glass bulb neck and the plug headpiece, and is dimensioned so as to close/plug the inlet of the coupling seat of the socket abutting against the body of the latter.

Incandescent light-bulbs made as described above obviously require special sockets suitably structured for accommodating and firmly retaining the light-bulb plug. Long-life incandescent light-bulb sockets which are currently used in front and rear automotive lights consist of a supporting platform made of plastic material and provided with a coupling seat shaped so as to house the long-life incandescent light-bulb plug; two electricity supply clamps which are placed at the bottom of the coupling seat, and are structured so as to clamp the headpiece of the plug while touching the terminals of the two rheophores emerging from the same headpiece; and a series of locking tongues which overhangly extend from the supporting platform, close to the inlet of the coupling seat, and are shaped so as to snappingly close behind the peripheral flange of the plug, so as to indefinitely retain the light-bulb plug in place within the coupling seat.

Unfortunately, experimental tests have shown that the above-described sockets are not capable of effectively opposing the vibrations of the plug which are oriented parallel to the longitudinal axis of the light-bulb, with detrimental consequences on the light- bulb filament life when the sockets are used in lighting equipment continuously subject to mechanical vibrations.

In the current long-life incandescent light-bulb sockets, indeed, the locking tongues are integrally made in one piece with the supporting platform, obviously made of plastic material, and the distal ends of the locking tongues are provided with stop teeth which overhangly protrude into the periphery of the coupling seat mouth, while remaining at a slightly higher height from the seat mouth than the nominal thickness of the peripheral plug flange, so as to be capable of placing above the peripheral flange when the peripheral flange abuts against the coupling seat mouth. The stop teeth are furthermore shaped so that the lower lateral flank of the tooth (i.e. the lateral flank directly facing the coupling seat mouth) is locally parallel to and facing the upper/rear face of the peripheral flange which closes the coupling seat mouth, so as to indefinitely prevent the plug from being extracted from the coupling seat without the preliminary manual opening of the locking tongues.

Unfortunately, the actual thickness of the peripheral plug flange varies according to the light- bulb model, and may also vary among light-bulbs belonging to a same model, therefore it often occurs that, between the lower lateral flank of the stop tooth and the peripheral plug flange, mechanical clearances having a width even larger than one millimetre are formed, with all the drawbacks that this causes on the coupling stability between light-bulb and socket.

The automotive lights obviously are lighting equipments continuously subject to especially strong mechanical vibrations, thus in automotive lights the actual life of the long-life incandescent light-bulbs is usually shorter than the theoretical one, partially nullifying the advantages related to the use of this particular type of light-bulbs.

DISCLOSURE OF INVENTION

Aim of the present invention is to provide a long- life incandescent light-bulb socket which is capable of effectively opposing the light-bulb vibrations which cause the early breaking of the filament, while meeting all the restrictions provided by the international standards related to light sources for use in the automotive field.

In compliance with the above aims, according to present invention according there is provided a long- life incandescent light-bulb socket as specified in Claim 1 and preferably, though not necessarily, in any one of the dependent claims.

In compliance with the above aims, according to present invention there is furthermore provided an automotive light as specified in Claim 11.

BRIEF DESCRIPTION OF THE DRAWINGS

A non-limiting embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

- Figure 1 is a perspective view of a long-life incandescent light-bulb socket realized according to the teachings of the present invention;

- Figure 2 is a sectional view of the socket shown in Figure 1 ;

- Figure 3 is an exploded perspective view of the socket shown in Figure 1; - Figure 4 is an exploded perspective view of an automotive light including a long-life incandescent light-bulb socket and realized according to the_ teachings of the present invention; whereas

- Figure 5 is an exploded perspective view of a constructional variation of the light-bulb socket shown in Figure 1.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to figures 1, 2 and 3, reference number 1 indicates as a whole a light-bulb socket specifically structured for housing/supporting a long- life incandescent light bulb 2, such as for example the incandescent light-bulbs recently marketed by Philips with the name "HiPerVision" .

This special type of light-bulb complies with the

E.C.E. R37 standard, and comprises a glass bulb 3 with a substantially spherical-ampoule shape that houses the incandescent filament of the light-bulb (not shown) ; and a plastic-material connection plug 4 which is arranged to close the neck of glass bulb 3 and is structured so as to be forcedly inserted/fitted within a special coupling seat provided in the light-bulb socket 1, with no rotation of the light bulb 2 about the longitudinal axis L the latter.

More in detail, plug 4 is provided with a headpiece

4a which houses the terminals of the two rheophores bringing the electric current up to the filament (not shown) placed within the glass bulb 3, and is shaped so as to mesh/penetrate into the coupling seat of light- bulb socket 1, so as to placed the terminals of the two rheophores close to the bottom of the same coupling seat ^' ; and with a ^" peripheral stabilizing flange 4b which is approximately annular in shape and overhangly protrudes from the body of plug 4, between the neck of glass bulb 3 and the headpiece 4a, and is dimensioned so as to close/plug the mouth of the coupling seat of light-bulb socket 1 when abutting against the body of the latter.

With reference to figures 1, 2 and 3, light-bulb socket 1 comprises: a supporting platform 5 which is preferably, though not necessarily, made of plastic material, and is provided with a coupling seat 5a shaped so as to accommodate/house the portion of plug 4 beneath the peripheral flange 4b, i.e. the plug headpiece 4a, without allowing light-bulb 2 to rotate about the longitudinal axis L of the latter; and two electrical connection members 6 which are placed close to the bottom of the coupling seat 5a, and are structured so to be able, when plug 4 is fully inserted into the coupling seat 5a, to clamp and/or only touch the two portions of the plug headpiece 4a where the terminals of the two rheophores are placed, so as to allow the electric energy to pass to the rheophores.

More in detail, the coupling seat 5a is provided with a preferential plug insertion and extraction axis A, and is shaped so as to accommodate the light-bulb plug 4 only when the longitudinal axis L of the light bulb coincides with axis A and the plug 4 faces and is perfectly aligned with the coupling seat 5a. Obviously, the longitudinal axis L of light-bulb 2 substantially coincides with axis A, when plug 4 is fully inserted into the coupling seat 5a.

In the example shown, in particular, the supporting platform 5 is preferably, though not necessarily, provided with a preferably, though not necessarily, substantially parallelepiped-shaped, central projecting ledge which overhangly extends upwards, and the coupling seat 5a extends within the projecting ledge from the top of the latter. The mouth of the coupling seat 5a is thus placed on top of the central projecting ledge, substantially coaxial to the reference axis A of the coupling seat 5a.

The electrical connection members 6, instead, preferably, though not necessarily, consist of two preferably, though not necessarily, metal type, electrically-conductive material sheets 6 which are substantially U-folded so as to form corresponding clamps 6 dimensioned for enclosing the headpiece 4a of plug 4, and are attached to the bottom of the coupling seat 5a so that each of them can enclose and clamp a corresponding portion of headpiece 4a of plug 4, so as to touch the terminal of a corresponding rheophore of light-bulb 2.

The two clamps 6 are obviously connected to an electric power-supply circuit which is fixed to the supporting platform 5 in a known manner.

More in detail, with reference to Figure 3, in the example shown each clamp 6 is integrally obtained in one piece with the end of a corresponding electricity supply strip 7 which is substantially inverted-U folded, and is fixed astride the top edge of the central projecting ledge of the supporting platform 5, so as to have an starting segment adhered to the outer surface of the central ledge of platform 5, and a final segment which extends within the coupling seat 5a and forms the corresponding clamp 6. The starting segment of strip 7, instead, is connected to the electric power-supply circuit fixed in a known manner to the supporting platform 5.

With reference to Figures 1, 2 and 3, light-bulb socket 1 is further provided with a light-bulb retaining member 8 which is located on the supporting platform 5, substantially at the mouth of the coupling seat 5a, and is structured so as to hook, once plug 4 of light-bulb 2 has been fully inserted into the coupling seat 5a on the supporting platform 5, the peripheral flange 4b of plug 4 for indefinitely preventing the same plug 4 from being subsequently extracted from the coupling seat 5a, unless a direct manual action is exerted on the retaining member 8.

Unlike the current long-life incandescent light- bulb sockets, however, in light-bulb socket 1 the light- bulb retaining member 8 is also structured so as to continuously exert, on the peripheral flange 4b of plug 4 that engages the coupling seat 5a, an elastic traction force directed towards the bottom of the coupling seat 5a, so as to push/retain plug 4 within the coupling seat 5a.

In other words, the elastic traction force is adapted to push and then retain the peripheral flange 4b of plug 4 in abutment against the body of the supporting platform 5, at the mouth of the coupling seat 5a.

More in detail, the light-bulb retaining member 8 comprises a number, of flexible locking tongues 9 which overhangly extend from the supporting platform 5, locally remaining substantially orthogonal to the lying plane of the mouth of coupling seat 5a, i.e. locally remaining substantially parallel to the reference axis A of the coupling seat 5a, and are suitably distributed about the mouth of the coupling seat 5a so as to form a sort of projecting crown 8 which surrounds and towers above the mouth of coupling seat 5a.

With reference to Figures 2 and 3, the distal ends 9a of the tongues 9 are further shaped so as to form, on top of the projecting crown 8, a converging/diverging throttling 8a with a substantially double-frustoconical profile, and are capable of reciprocally moving away so as to allow the converging/diverging throttling 8a to elastically dilate so to let the peripheral flange 4b of plug 4 pass, and then of closing back behind the peripheral flange 4b while leaving the lower portions of the distal ends 9a of the tongues, i.e. the portions of the distal ends 9a forming the diverging portion of the converging/diverging throttling 8a, in abutment against the peripheral edge of the peripheral flange 4b of plug 4.

Furthermore, the distance/height of the diverging segment of the converging/diverging throttling 8a from the mouth of the underlying coupling seat 5a is shorter than the minimum nominal thickness of the peripheral plug flange 4b, thus the peripheral plug flange 4b moves in abutment against the body of the supporting platform 5 before tongues 9 have returned to the position prior to the insertion of plug 4.

With reference to Figures 1 and 3, the distal end

9a of at least one of the flexible locking tongues 9 is further provided with at least one auxiliary stop anchor or tooth 10 which is shaped so as to overhangly protrude from the body of tongue 9 towards the interior of the converging/diverging throttling 8a, roughly at the converging segment of the latter, and is shaped so as to dig onto the back/upper face of the peripheral flange 4b of plug 4 which engages the coupling seat 5a, so as to prevent the reciprocal moving away of the distal ends 9a of tongues 9 up to allow the extraction of the peripheral flange 4b from the projecting crown 8.

With reference to Figures 1, 2 and 3, in the example shown, in particular, the light-bulb retaining member 8 comprises two flexible locking tongues 9 which are arranged on opposite sides of the mouth of coupling seat 5a, parallel to and facing each other, so that the distal ends 9a of the two tongues 9 are arranged on opposite sides of the reference axis A of the coupling seat 5a.

Preferably, though not necessarily, the distal ends 9a of the two flexible locking tongues 9 are further both provided with two auxiliary stop anchors or teeth 10, which overhangly protrudes from the two lateral flanks of tongue 9 towards the centre of the converging/ diverging throttling 8a, thus forming a sort of fork which is located right above the diverging segment of the converging/diverging throttling 8a.

More in detail, with reference to Figures 2 and 3, each flexible locking tongue 9 preferably, though not necessarily, consists of a metal sheet or strip 9 made of harmonic steel or other elastically deformable metal material, which has a lower segment rigidly trapped within the body of the supporting platform 5; an intermediate flexible segment which overhangly extends from the body of platform 5, beyond the mouth of the coupling seat 5a, thus remaining locally substantially parallel to the reference axis A of the coupling seat 5a; and finally an upper segment which is substantially obtuse-angle V-folded so as to approach and then move away from axis A.

The upper segments of the metal sheet or strips 9 forming tongues 9 are obviously facing each other so as to delimit the converging/diverging throttling 8a having a substantially double-frustoconical profile and which is located on top of the projecting crown 8·.

Two substantially L-shaped flat tabs are further obtained on top of the upper segment of each metal sheet or strip 9, which tabs overhangly extend from the two lateral flanks of sheet or strip 9 so as to form a sort of fork which extends towards axis A of the coupling seat 5a, thus remaining above the elbow of the substantially V-folded upper segment.

The substantially L-shaped flat tabs form the two auxiliary stop anchors or teeth 10 which are adapted to dig onto the rear/upper face of the peripheral flange 4b of the plug 4 that engages the coupling seat 5a, so as to prevent plug 4 from being extracted from the coupling seat 5a.

With reference to Figure 4, light-bulb socket 1 is especially suitable for being used within a front or rear light 101 for motor vehicles and the like, in order to support a long-life incandescent light-bulb with the features of light-bulb 2.

More in detail, the automotive light 101 comprises: - a rigid rear body 102 which is substantially basin-shaped and is structured so as to be recessed within a compartment specifically realized in the front or rear part of the vehicle body, or in any case fixed onto the front or rear part of the vehicle body; - at least one light source 103 which is located close to the bottom of the rear body 102, and is structured so as to emit light when electricity powered; and finally ^*

- at least one reflecting cup-like body (not shown) which is fitted onto the light source 103 with the concavity facing the mouth of the rear body 102, and has the inner surface structured so as to deviate/direct the light produced by the light source 103 towards the mouth of the rear body 102; and

- a front lenticular half-shell 104 which is at least partially made of a transparent or semi- transparent material, and is arranged to close the mouth of the rear body 102 so to be crossed by the light emitted by the light source 103, and so to emerge outside the vehicle body (not shown) .

More in detail, in the example shown, automotive light 101 is provided with three independent light sources 103 which are fixed on a light-bulb bottom plate 105 which is structured so as to be fixed in a rigid and stable, though easily detachable, manner to the back of the rear body 102, so that the light sources 103 can protrude within the respective reflecting cup-like bodies, via a pass-through opening conveniently made on the bottom of the rear body 102.

Lenticular body 104 instead is made of a transparent or semi-transparent plastic material, optionally coloured, and is provided with three separate transparent or semi-transparent portions, each facing a respective light source 103.

With reference to Figure 4, at least one of the "three light 'sources 103 (two in the example shown) consists of a known type a long-life incandescent light- bulb 2, and the light-bulb socket bottom 105 is provided with a corresponding long-life incandescent light-bulb socket 1 which is adapted to support and power the aforesaid long-life incandescent light-bulb 2.

General operation of the light-bulb socket 1 is easily inferable from the above description, and therefore does not require any further explanations.

As regards instead the light-bulb retaining member 8, the particular shape of the distal ends 9a of the two or more flexible locking tongues 9 forming the retaining member 8 allows the tongues 9 to exert, on the peripheral plug flange 4b, an axial elastic force that continuously tends to push the peripheral flange 4b towards the mouth of the coupling seat 5a, and the plug headpiece 4a in abutment against the bottom of the coupling seat 5a.

The lower portions of the distal ends 9a of the flexible locking tongues 9, in fact, are inclined relative to the lying plane of the peripheral plug flange 4b, thus the distal ends 9a of the tongues, when trying to return to the position occupied prior to the insertion of plug 4, tend to push the peripheral plug flange 4b downwards. The distance separating the mouth of coupling seat 5a from the lower portions of the distal ends 9a of the flexible locking tongues 9, i.e. the portions of the distal ends 9a forming the diverging segment of the converging/diverging throttling 8a, is however lower than the minimum nominal thickness of the peripheral plug flange 4b, thus the peripheral plug flange 4b moves in abutment against the body of the supporting platform 5 before tongues 9 can return the distal ends 9a to the original position.

The failed return of the flexible locking tongues 9 to the home position results in an elastic axial force which continuously tends to push the peripheral flange 4b of plug 4 in abutment against the body of the supporting platform 5, and firmly retain plug 4 within the coupling seat 5a, thus preventing it from vibrating within the seat.

The stop anchors or teeth 10 instead prevent any movement of the distal ends 9a of the tongues 9 relative to the peripheral plug flange 4b, thus preventing the tongues 9 from accidentally opening and the plug 4 from escaping. In fact, in order to open the light-bulb retaining member 8, manually acting on the distal ends 9a of tongues 9 is required in order to force the opening of tongues 9.

The advantages are related to the particular structure of the light-bulb retaining member 8 are large in number. Firstly, the light-bulb socket 1 prevents plug 4 of light-bulb 2 from freely vibrating within the coupling seat 5a, to the advantage of the life of the incandescent filament of light-bulb 2.

Moreover, the particular shape of the distal ends

9a of the tongues 9 allows the flexible locking tongues 9 to be entirely made of metal material, for example by shearing and press-bending a metal sheet or strip, thus eliminating all the problems related to the high temperatures reached at the surroundings of the glass bulb 3 of light-bulb 2. In fact, metal is able to stand high temperatures much better than plastics.

Moreover, due to the particular structure of the light-bulb retaining member 8, light-bulb socket 1 is further capable of retaining light-bulb 2 in place also in presence of especially strong, impulsive mechanical strains, such as those generated when the hatch of a car is vigorously closed. Accordingly, light-bulb socket 1 is adapted to be used in automotive lights which are to be mounted to car hatches, or in the immediate vicinity thereof.

Furthermore, light-bulb socket 1 can now accommodate any model of long-life incandescent light- bulb without any drawbacks. In fact, it is sufficient for the thickness of the peripheral plug flange 4b of light-bulb 2 to be shorter than the distance separating the mouth of coupling seat 5a from the diverging section of the converging/diverging throttling 8a to produce an elastic force sufficient for firmly retaining the peripheral plug flange 4b in abutment against the body of the supporting platform 5.

It is finally apparent that changes and variants can be made to the above-described light-bulb socket 1 without departing from the protective scope of the present invention.

For example, with reference to Figure 5, in a different embodiment, the flexible locking tongues 9 forming the light-bulb retaining member 8 may be integrally made in one piece with the electricity supply strips 7 which connect clamps 6 to the electric power- supply circuit placed on the supporting platform 5.