EP1173906A1

EP1173906A1 - Safety socket

Info

Publication number: EP1173906A1
Application number: EP00910485A
Authority: EP
Inventors: Yves Bonard; Jean-Luc Damond; Philippe Moret
Original assignee: Dolsimer Investment SA
Current assignee: Dolsimer Investment SA
Priority date: 1999-05-03
Filing date: 2000-03-29
Publication date: 2002-01-23
Anticipated expiration: 2020-03-29
Also published as: EP1173906B1; US6491534B1; CA2373092A1; AU3270100A; WO2000067349A1; CA2373092C; DE60015113D1; ATE280444T1

Abstract

A socket for an electric light is provided including a first electric supply circuit, a second electric supply circuit, and a safety device adapted to detect presence or absence of a light bulb in the socket.

Description

Safety socket

The present invention relates to a safety socket for an electric bulb with screw base or bayonet.

Many electrocution accidents occur when an electric socket intended to receive an electric bulb is not equipped with its bulb, while it is connected to a live power supply line. As safety regulations provide that voltage is applied to the central contact pad of the socket, an accident may occur when a finger or a tool, such as a screwdriver, is inserted inside the empty socket. contact with the central contact pad.

In the relatively common case where, following an assembly by an unqualified person of the socket or the power cable, the phase voltage is applied to the contact tube of the socket instead of the central stud, an accident can very easily arrive since this contact tube is relatively poorly protected from the outside, since normally it is connected to the neutral conductor.

Likewise, an electrocution accident can occur when a bulb is broken in a socket and a portion of the bulb's electrical circuit remains energized and is no longer protected by the glass of the bulb. In this case also contact by a finger or a tool can be dangerous.

There are sockets fitted with a switch, which can be operated by hand, making it possible to interrupt the supply circuit of the central contact pad. Since these switches are generally rotary, it is impossible for the user to know whether the supply circuit of the central contact pad is interrupted or not. The switch of such a socket is rather intended to switch the bulb on or off rather than to operate as a safety device. Application EP-AO 744 792 describes a socket fitted with a safety disc which lowers when the bulb is introduced into the socket. The safety disk is provided with a through contact to ensure the connection between the base contact of the base of the bulb and a contact pad at phase voltage. This embodiment corresponds to the prior art closest to the invention which is introduced in the preamble of the independent claims. The safety disc is, in this document, provided with another through contact for the passage of neutral, this contact being connected with a flexible conductive blade pressing on the thread of the base of the bulb. This conductive strip represents a danger for the user, because it is easy, when there is no bulb in the socket, to bend this strip with the fingers or a tool and to put it under tension, in particular in the case where the phase and neutral conductors have been reversed.

Application EP-A-0.027.244 describes a socket provided with a safety device of very complicated construction, therefore not very reliable to use. As before, a movable conductive strip is responsible for ensuring the connection to neutral with the same drawback as mentioned above.

A first object of the invention is to propose a safety socket for an electric bulb provided with a safety device making it possible to prevent accidental contact with any accessible conductive part of the socket.

A second object of the invention is to propose that the previous safety socket be provided with a safety device able to operate regardless of the way in which said socket is connected to the power cable.

Another object of the invention is to propose a safety socket provided with a safety device of simple and reliable design in use. Another object of the invention is to propose a safety socket provided with a safety device with redundant safety.

Yet another object of the invention is to propose that the safety socket be provided with a lockable safety device.

Transition sockets are also known which make it possible to install a bulb provided with a base having a determined diameter in a socket having an equal or different diameter.

On this basis, another object of the invention is to propose a transition socket provided with one or the other of the preceding safety devices.

These objects are obtained by a safety socket, a first embodiment of which is described in claim 1, while a second embodiment is described in claim 2, particular or variant embodiments being described in dependent claims.

Several embodiments and variants of a safety socket according to the invention are described in detail below, this description, mentioning still other advantages of the invention, being to be considered with regard to the appended drawing comprising the figures or:

FIG. 1 schematically shows a sectional section of a socket provided with a safety device according to a first embodiment of the invention in the disconnected state,

FIG. 2 schematically shows the same portion of socket, in the connected state when a bulb has been inserted into the socket,

Figure 3 schematically shows a section along the line lll-lll in the figure. ,

FIG. 4 schematically shows a sectional section of a socket provided with a safety device according to a second embodiment in the disconnected state,

FIG. 4A shows a detail of the previous figure,

FIG. 5 schematically shows the same portion of socket, in the connected state when a bulb has been inserted into the socket,

FIG. 6 schematically shows a sectional section of a socket provided with a safety device according to another embodiment in the disconnected state,

FIG. 7 schematically shows a sectional section of a socket provided with a safety device according to yet another embodiment in the disconnected state,

FIG. 8 schematically shows a first version of a device for locking a safety device for a socket,

FIG. 9 schematically shows, in a partial section in elevation, a second version of a locking device for a safety device for a socket,

FIG. 10 is a partial section in plan along the line X-X of the previous figure,

FIG. 11 schematically shows a socket fitted with a safety device according to yet another embodiment of the invention, FIG. 12 schematically shows a transition socket fitted with a safety device, and

FIG. 13 schematically shows another transition socket also fitted with a safety device.

The sockets and devices mentioned below and shown in the figures are only described and shown very schematically, essentially in order to make them understand their operation. The details of construction and execution, in particular the electrical connections between the various elements, are not described in all their details being within the reach of those skilled in the art.

Conventionally, the socket 1 of FIG. 1, for a bulb with a screw base, comprises a threaded metal tube 10, inserted in an insulating support 11 as well as a central contact pad 12. A first contact terminal 100 receives the neutral conductor of the socket supply cable (not shown), while a second contact terminal 120 receives the phase conductor. Usually in conventional sockets, the contact terminal 120 is directly connected to the central contact pad 12 while the contact terminal 100 is connected to the metal tube 10.

Figures 1, 2 and 3 show a screw socket 1 provided with a safety device 2 according to a first embodiment, consisting of an insulating safety disc 20. In this first variant, the central contact pad 12 is directly connected to terminal 120. The disc 20 consists essentially of an insulating material and is provided with several radial extensions 21, also insulating, each of said extensions 21 being housed in a recess 1 10 of the insulating support 1 1 and / or of the threaded tube 10. A spring means 22 is disposed between the bottom of the socket 1 and the disc 20, acting so as to move the disc 20 away from the bottom of the socket, respectively from the central contact pad 12. Shoulders 1 1 1 limit the recesses 1 10 towards the outside of the sleeve, preventing the disc 20 from coming out of the sleeve. The insulating disc 20 comprises a pad of contact 200, arranged in the center of the disc 20 and passing through the disc in the direction of the longitudinal axis of the sleeve.

The disc 20 further comprises a conductive track 201 on its underside, insulated relative to the patch 200. A possible trace of this conductive track 201 is visible in FIG. 3. The bottom of the socket comprises, in addition to the central stud 12, connected to terminal 120, two pads 13 and 14 arranged on either side of the central pad 12, facing portions of the conductive track 201. The pad 14 is connected to the neutral terminal 100, while the stud 13 is connected to the threaded tube 10.

It is thus understood that when there is no bulb in the socket, as can be seen in FIG. 1, the disc 20 is pushed back by the spring 22, the extensions 21 being guided by the recesses 110 and coming in abutment against the shoulders 1 11, so as to close the bottom of the socket, or to prevent that when a finger or a tool is inserted into the socket, it does not come into direct contact with the central stud 12 under tension. In the same way, the neutral circuit connecting the threaded tube and the terminal 100 is interrupted, preventing in the event of a phase and neutral reversal during assembly, that a voltage appears on the portion of the threaded tube 10 easily accessible from the outside of the socket.

The metal parts easily accessible from the outside of the socket 1, conductive patch 200 and conductive tube 10, are thus completely galvanically isolated from the network.

By screwing a bulb 3 into the socket, as seen in FIG. 2, the base contact 31 of its base 30 pushes the disc 20 towards the bottom of the socket, until the contact pad 200 comes into contact with the central pad 12 and that simultaneously the conductive track 201 comes into contact with the two contact pads 13 and 14.

Thus, the passage of current is established, from the contact terminal 120 under voltage, to the contact pad 12 and via the patch of contact 200 to the base contact 31, the circuit closing from the base 30 to the threaded tube 10 connected to the contact pad 13, then via the conductive track 201 to the contact pad 14, itself connected to the contact terminal 100, at neutral potential.

Alternative embodiments are obviously possible for this first embodiment of the safety device. For example, the disc 20 has been shown in FIG. 3 with four radial extensions 21, but it is obvious that it could include a different number. Preferably the disc 20 will be provided with at least two radial extensions 21. Likewise the spring means 22 may be arranged differently from what is shown here or replaced by any elastic means fulfilling the same function as that described. On the other hand, the two studs 13 and 14 can be arranged at any places on the bottom of the socket, the conductive track 201 having a shape suitable for establishing contact between these two studs.

Such a safety device, according to the first embodiment described above, can also be adapted for a socket intended to receive a bulb with bayonet base. There are generally known two types of sockets for bayonet bulbs: a first type, generally used for an AC voltage, in which there is a central contact pad, similar to pad 12 described above and a smooth contact tube having the same electrical function that the threaded tube 10 described above and a second type, generally used for direct tension, comprising two contact pads arranged side by side at the bottom of the socket. For sockets of the first type (central stud and contact tube), the construction and operation of the safety device are similar to what has been described above. For the sockets of the second type (two contact pads side by side), the disc 20 will include two through contact pads, each being capable of bringing one of the pads into contact with the bottom base contact corresponding to the base of the 'bulb.

A second embodiment of a security device is visible in Figures 4, 4A and 5.

According to this embodiment, the electrical connection between the threaded or conductive tube 10 and the contact terminal 100 is not cut by the movement of the disc 20, as described above, but by an independent auxiliary breaking means 4.

This auxiliary cut-off means 4 consists, as can be seen in FIGS. 4, 4A and 5, of a lever or pusher 40, made of insulating material, capable of being moved radially in a bore 1 12 arranged in the insulating support 1 1 and the conductive tube 10. The bore 1 12 opens into a housing 1 13 arranged in the insulating support 1 1.

The rear portion of the pusher 40 comprises a pad or a contact element 400, a stop ring 41 and an elastic means, for example a spring 42, capable of pushing the pusher 40 radially towards the interior of the conductive tube 10 The movement of movement of the pusher 40 is limited by the stop ring 41. A second pad or contact element 401 is disposed in the housing 1 13, opposite the pad 400. One of the two pads, preferably the pad 401 is directly electrically connected to the contact terminal 100, while the other pad, preferably the pad 400, is directly electrically connected to the conductive tube

10.

Thus, as can be seen in FIG. 4A, when no bulb is inserted into the socket 1, the spring 42 pushes the pusher 40 inward, thereby separating the two pads or contact elements 400 and 401 interrupting the neutral electrical circuit connecting the contact terminal 100 to the conductive tube 10. The phase circuit is interrupted as before by the elevation of the insulating disc 20.

As shown in Figure 5, when a bulb 3 is inserted into the socket 1, the introduction of the base into the tube 10, pushes on the one hand the insulating disc 20 for the establishment of the circuit phase, as described above and on the other hand pushes the plunger 40 radially outwards, thus establishing the electrical contact of the neutral circuit between the pads or contact elements 400 and 401.

We therefore established the phase circuit and the neutral circuit during the introduction of a bulb into the socket, as well as cutting these two circuits when removing the bulb, by two independent cutting means.

Another embodiment of a safety socket is visible in Figure 6.

This safety socket includes the devices described above, arranged so that there is a double break both on the phase circuit and on the neutral circuit. Such an arrangement can be useful in certain cases where the safety socket is used in a humid atmosphere or environment.

The socket is similar to that described above with reference to FIGS. 1 to 3, except that it additionally comprises an auxiliary cut-off device 4 as described with regard to FIGS. 4 and 5 with the difference that this cut-off device auxiliary is interposed between the contact terminal 120 and the contact pad 12. Thus, there is a double break of the phase circuit by the pads or contact elements 400 and 401 as well as by the contact pad 12 and the contact pad 200 and a double break of the neutral circuit by the pad 13 and the conductive track 201 as well as between the same conductive track and the contact pad 14.

Figure 7 shows yet another embodiment of a safety socket in which the phase circuit is secured as before by a first auxiliary cut-off device 4 followed by, disc 20, while a second auxiliary cut-off device 4, is inserted in the neutral circuit. This provides security maximum, in particular in the case where the disc 20 has been forced or broken as well as when the sleeve works in a humid atmosphere or environment.

As with the first embodiment of the safety device described, the other embodiments mentioned can be adapted to bayonet sockets of one or other of the types described.

Other constructive arrangements than those described above can be envisaged for a safety device 4 used for a socket according to the proposed embodiments. For example, the spring means 42 can be arranged differently from what is shown in the figure, which can be replaced by any elastic device having an equivalent effect, or the same effect of connection and disconnection of two contact pads can be obtained by a tilting lever, one end of which projects into the threaded tube or any isolated actuating device having an equivalent effect. On the other hand, the conductive tube 10, threaded or smooth, can be replaced by an insulating tube having the function of fixing the bulb, while the power supply function can be obtained by a tongue or any conductive portion disposed on said insulating tube and able to come into contact with the base of a bulb introduced into the socket.

If a safety socket fitted with a device according to one or other of the embodiments presented already offers a first level of safety by preventing direct accidental contact with a live conductive portion of the socket, an additional device locking the disc 20 in a position remote from the central stud 12 may be appropriate so as to prevent the disc 20 from being able to be moved by pressing it in with a finger or a tool, without a bulb being inserted into the socket.

A first version of a locking device 5 is shown schematically in plan in Figure 3 and in elevation in Figure 8. The locking device 5 consists here of a lever 50 mounted on a pivot 51 adapted to pivot about an axis 511 perpendicular to the longitudinal axis of the sleeve as well as to slide along said axis 511. The lever 50 comprises a shoulder 52 comprising an inclined plane 520 and a flat 521 as well as a push button 510 protruding from the external wall of the socket. The device is completed with a first elastic means, for example a spring 53, shown here by a leaf spring, capable of holding the lever 50 in the locking position parallel to the longitudinal axis of the sleeve, as well as a second elastic means, for example a spring 54, capable of pushing the lever 50 radially, respectively the push button 510 outwards. The lever 50 is able to pivot by a determined angle around the axis 51 1 and to slide by a determined value, in a housing 114 arranged for this purpose in the insulating support 11. The nearest radial extension 21 of the locking device 5 comprises a notch 210, turned towards the side of the locking device and of width slightly greater than the thickness of the lever 50.

When a bulb is placed in the socket and it is removed by unscrewing it, the disc 20 accompanies the movement of withdrawal of the base of the bulb, being pressed by the spring 22 seen in FIG. 1. During this displacement , the radial extension 21 meets the inclined plane 520 and makes the lever 50 pivot in the direction indicated by the arrows in FIG. 8. When the radial extensions 21 of the disc 20 come into abutment against the shoulders 111, the lever 50 returns rest position under the action of the spring leaf 53, the flat 521 then preventing a new displacement of the disc 20 towards the bottom of the sleeve by retaining the extreme portion of the radial extension 21, as seen in plan on the lower portion of Figure 3. The disc 20 is thus locked in position such that contact with the central contact pad 12 is impossible. In order to allow a new bulb to be installed in the socket, it is necessary to unlock the disc 20. For this, it is sufficient to press the push button 510, which pushes the lever 50 towards the notch 210, as it can be seen in the upper portion of FIG. 3. Thus the disc 20 is unlocked and can be lowered towards the bottom of the socket during the introduction of the bulb in order to allow the central stud 12 to come into contact with the bottom contact of the bulb base, the studs 13 and 14 respectively with the track conductive 201. Preferably there will be two locking devices 5, each acting on a radial extension, preferably opposite relative to the longitudinal axis of the sleeve. In this way, the disc 20 is held by two opposite extensions, which avoids biasing it, the unlocking of the disc 20 then necessitating acting in opposition at two opposite points of the sleeve.

According to another version of a locking device visible in FIGS. 9 and 10, the locking device 6 operates in a manner quite similar to that which has just been described above, the difference being that the unlocking takes place automatically when inserting a bulb into the socket. For this, the device 6 is provided with a pusher 60, similar to the pusher 40 described previously with reference to FIG. 4, the end of the pusher 60 disposed in the recess 113 carrying a lever 61 provided like the lever 50 seen more top of a stop flat. In this case, the movement of the lever 61 to unlock the disc 20 is made radially outward.

By inserting a bulb into the socket, the base pushes the pusher 60 outwards, in opposition to the elastic means represented by the spring 62, as described above with reference to FIGS. 4 and 5. The lever 61 is thus moved towards the free end of the extension 21 or the notch 210 which is arranged therein, so as to release the extension 21 retained by the flat, respectively allow the disc 20 to move towards the bottom of the socket. When the bulb is removed, the disc 20 is pushed by the spring 22 until the extensions 21 come into abutment against the shoulders 1 1 1, the complete withdrawal of the bulb releasing the pusher 60, which under the effect of the spring 62 blocks the extension 21 under the flat portion of the lever 61. According to this latest version, the locking means 6 are actuated automatically during introduction or removing a bulb and therefore do not require any manipulation for their activation.

It is obvious that the edges of the elements of the locking device in operational contact, for example the edge of the radial extension 21 in contact with the lever 50 or 61 according to one or other of the versions described, are formed, for example bevelled or rounded, so as to facilitate the sliding of these elements between them.

Other versions or variants of the locking device can be envisaged. For example, the upper portions of the guide recesses 1 13 may each include an additional recess, disposed on a portion of the periphery of the sleeve, perpendicular to the corresponding guide recess, the disc 20 further comprising at least one control lever. , for example a radial extension of an extension 21, accessible from outside the sleeve, said lever allowing, when the disc is in the abutment position in the upper portion of the guide recesses, to rotate it by a portion of turn so as to engage the extensions in the additional recesses, so as to lock the disc, a pivoting in the opposite direction making it possible to unlock it. Said lever can be actuated manually or using a tool. Similarly, as a variant to the pusher 60 of FIGS. 9 and 10, one could for example have a pivoting lever, controlling the lever 61, and one end of which would project into the threaded conductive tube 10 or any other isolated actuation device.

It is obvious that the versions described above of the locking means of the disc 20 can also be adapted to a disc 20 arranged in a bayonet socket according to one or other of the types mentioned above.

We have seen that the safety device 4 comprising, as described above, a pusher 40 projecting inside the conductive tube 10 is of construction quite similar to the locking device 6 which has just been described. These two devices can therefore advantageously be grouped under a common device, the actuation of the pusher by the introduction of a bulb base ensuring on the one hand an electrical contact and on the other hand unlocking the insulating disc 20.

Figure 1 1 shows another safety device 7 for detecting the presence or absence of a bulb 3 in the socket. In this case, instead of detecting the presence or absence of the base 30 in the threaded tube as described so far, the device 7 detects the presence or the absence of the glass 32 of the bulb 3. This safety device is particularly useful in order to prevent a portion of the bulb 3 remaining under tension when the glass 32 is broken, in particular by vandalism.

The safety device 7 here consists of at least one lever or pusher 70, able under the effect of an elastic means, for example a spring 71, to detect the presence or absence of the glass 32. In the embodiment shown in the figure, the pusher 70 is housed in a recess 1 15 of the insulating support 1 1 and is capable of sliding parallel to the longitudinal axis of the sleeve. The spring 71 pushes the pusher 70 outwards, respectively in the direction of the glass 32 so that a first end 72 of the pusher can come into contact with the glass 32. The other end of the pusher 70 is provided with a contact means 73 capable of establishing an electrical connection with a second contact means 74.

It can be seen in the figure that the end 72 of the pusher 70 drawn on the left-hand part does not detect the presence of a glass 32, causing the pusher to be pushed completely outwards under the effect of the spring 71 interrupting the electrical connection between the contact means 73 and 74, while the end 72 of the pusher drawn on the right-hand part detects the presence of a glass 32, causing the pusher is pushed inwards establishing the electrical connection between the contact means 73 and 74.

Since when a glass 32 is broken, glass fragments are likely to remain attached to the base 30, it may be advantageous to have several safety devices 7 capable of detecting the presence of the glass 32 on the periphery of the socket, so that in the event of broken glass, at least one pusher 70 is actuated to cut the electrical supply circuit. In this case, it is advantageous that the contact means 73 and 74 of each of the pushers 70 are mounted in series, as shown in the figure.

As previously, alternative embodiments can be envisaged, in particular the replacement of the pushers 70 with tilting levers or other actuating devices having a similar effect.

Figure 1 1 shows yet another safety device 8, independent of the previous one, consisting of a micro fuse 80 mounted on the circuit connecting the phase terminal 120 and the central contact pad 12. The micro fuse 80 can be changed from the outside of the socket.

The safety device 7 for detecting the glass 32 can be used alone, but preferably in combination with one or the other of the safety devices described above. The safety device 8 by micro fuse 80 is generally used in combination with one or the other of the safety devices described above.

A safety socket according to one or other of the embodiments or variants described finds numerous applications.

For example, it can be used as a socket mounted on a luminaire intended for a children's room. Several safety sockets can also be mounted in parallel, or in series in the case of a direct supply current, so as to form a light garland, for decoration or for the protection of a site for example. In this case, these garlands being quite often subject to vandalism, subsequent electrocution can be avoided.

FIG. 12 shows a transition socket 9 comprising a first conductive threaded tube 90, inside of which there is an insulating body 91 and a second conductive threaded tube 92. In this type of transition socket, the bulb whose diameter base is adapted to the diameter of the second threaded tube 92 is screwed into this second threaded tube while the transition sleeve itself is screwed into another sleeve adapted to the diameter of the first threaded tube 90. In known transition sockets, the two threaded tubes 90 and 92 are directly electrically connected and the central contact pad 12 is directly electrically connected to the base socket contact 93. Such a transition socket makes it possible to have a bulb having a base corresponding to the diameter of the second threaded tube 92 in a socket having a diameter corresponding to that of the first threaded tube

90.

On the safety transition bushing 9 in FIG. 12, a safety device 2 corresponding to the first embodiment described above has been provided, for example, a disc 20 provided with its contact pad 200 as well as conductive track 201 and operating exactly as described above. In this case, the phase contact terminal 120 is replaced by the base contact 93, while the neutral contact terminal 100 is replaced by the first conductive threaded tube 90.

The transition bushing 9 in FIG. 13 is different from that which has just been described in that the diameter of the first threaded tube 90 corresponds to that of the second threaded tube 92. Such a transition bushing would have no use in itself, unless it is provided with a safety device according to one or the other of the embodiments or variants described above. Such a transition socket therefore makes it possible to transform a normal socket into a safety socket. In the case of FIG. 12, and by way of example, the safety device is similar to that described with reference to FIGS. 4 and 5, except that the phase contact terminal 120 is replaced by the base contact 93, while the neutral contact terminal 100 is replaced by the first conductive threaded tube 90.

It should be understood here that a transition sleeve 9, of any type, either with or without variation in diameter, can be equipped with one or more safety devices as described above, according to one or the other of the embodiments or variants mentioned for a safety socket.

Preferably a transition sleeve 9, of any type, will be provided with a locking means of known technique, shown diagrammatically at 900 in FIGS. 12 and 13, allowing when the transition sleeve is mounted in another sleeve, make this assembly non-removable or more difficult to dismantle.

Those skilled in the art will be able to adapt the teaching provided here concerning the transition sockets provided with screw caps, to transition sockets provided with bayonet caps. The adaptation of this teaching to transition sockets allowing to pass from a screw socket to a bayonet lamp base or vice versa is also evident.

The safety or transition sockets described here apply particularly well to installations operating at normalized standard voltage, for example at 220V, but they could also be used for installations operating at higher or lower voltage, as well as to all the usual frequencies.

Claims

1- Socket (1; 9) for an electric bulb comprising a first electrical supply circuit, in particular for supplying a phase voltage, comprising at least one first contact pad (12) disposed at the bottom of the socket and a first contact piece (120; 93), as well as a second electrical supply circuit, in particular for supplying a neutral, comprising at least one fixing tube comprising at least one conductive portion (10; 92) inserted in an insulating support (11; 91) and a second contact piece (100; 90), said socket further comprising a safety device (2) capable of detecting the presence or absence of an electric bulb (3) in said socket, comprising a disc (20) of insulating material provided with a plurality of radial extensions (21), said disc being arranged in said socket so that the plane of said disc is essentially perpendicular to the longitudinal axis of the socket (1), said disc e being able to slide in the direction of said longitudinal axis of the sleeve, being pressed by an elastic means (22) to move away from the bottom of the sleeve, said radial extensions (21) being able to slide in recesses (110) arranged in the socket so as to guide said disc, a stop (111) being provided in at least one recess (110) so as to limit the sliding of the disc (20) towards the outside of the socket, said disc further comprising at least one conductive pad (200) passing through said disc capable of establishing electrical contact between the first contact pad (12) and a contact (31) at the bottom of the base of the electric bulb when the disc (20) is pressed against the bottom of the socket by said bulb introduced into the socket,

characterized in that

said disc (20) further comprises a conductive track (201), isolated from the conductive pad (200) and disposed on the face of said disc facing the bottom of the socket, said socket bottom further comprising two other contact pads (13,14) each arranged opposite a portion of said conductive track, a first of said other pads contact (13) being electrically connected to the conductive portion (10; 92) of the support tube.

2- Socket (1; 9) for an electric bulb comprising a first electrical supply circuit, in particular for supplying a phase voltage, comprising at least one first contact pad (12) disposed at the bottom of the socket and a first contact piece (120; 93), as well as a second electrical supply circuit, in particular for supplying a neutral, comprising at least one fixing tube comprising at least one conductive portion (10; 92) inserted in an insulating support (11; 91) and a second contact piece (100; 90, said socket further comprising a safety device (2) capable of detecting the presence or absence of an electric bulb (3) in said socket, comprising a disc (20) of insulating material provided with a plurality of radial extensions (21), said disc being disposed in said socket so that the plane of said disc is essentially perpendicular to the longitudinal axis of the sleeve (1), said disc being able to slide in the direction of said longitudinal axis of the sleeve, being pressed by an elastic means (22) to move away from the bottom of the sleeve, said radial extensions (21) being able to slide in recesses (110) arranged in the socket so as to guide said disc, a stop (111) being provided in at least one recess (110) so as to limit the sliding of the disc (20) towards the outside of the socket, said disc further comprising at at least one conductive pad (200) passing through said disc capable of establishing electrical contact between the first contact pad (12) and a contact (31) at the bottom of the base of the electric bulb when the disc (20) is pressed against the bottom of the socket by said bulb introduced into the socket,

characterized in that

the socket further comprises another safety device (4) comprising an isolated actuating device (40) having a first end projecting inside the socket and a second end arranged in a recess (1 13) of the support insulating and provided a first contact pad (400), a second contact pad (401) being disposed in said recess (1 13) opposite said first contact pad (400), elastic means (42) being provided to separate said contact pads from each other, the introduction of a base (30) of an electric bulb (3) into said socket actuating said isolated actuation device, thereby bringing the two said contact pads into contact contact (400,401), a first of said pads (400) being electrically connected to the conductive portion (10; 92) of the support tube while the second of said pads (401) is electrically connected to the second contact piece (100; 90) .

3- Socket according to one of claims 1 or 2, characterized in that the first contact pad (12) is electrically connected to the first contact piece (120; 93).

4- socket according to claim 1, characterized in that it comprises yet another safety device (4) comprising an isolated actuating device (40) having a first end projecting inside the socket and a second end disposed in a recess (113) of the insulating support and provided with a first contact pad (400), a second contact pad (401) being disposed in said recess (113) opposite said first contact pad (400 ), elastic means (42) being provided to separate said contact pads from one another, the introduction of a base (30) of an electric bulb (3) into said socket actuating said device isolated actuation, thus bringing the two said contact pads (400,401) into contact, a first of said pads (400) being electrically connected to the first contact pad (12) while the second of said pads (401) is rel electrically connected to the first contact part (120, -93).

5- Socket according to one of claims 1 or 4, characterized in that the second of said other contact pads (14) is electrically connected to the second contact piece (100; 90). 6- Socket according to one of claims 1 or 4, characterized in that it further comprises another safety device (4) comprising an isolated actuation device (40) having a first end projecting inside the sleeve and a second end disposed in a recess (1 13) of the insulating support and provided with a first contact pad (400), a second contact pad (401) being disposed in said recess (1 13) opposite said first contact pad (400), elastic means (42) being provided for separating said contact pads from each other, the introduction of a base (30) of an electric bulb (3) into said socket actuating said isolated actuating device, thus bringing two said contact pads (400, 401) into contact, a first of said pads (400) being electrically connected to the second of said other contact pads (14) while the second d Said pads (401) are electrically connected to the second contact piece (100; 90).

7- Socket according to one of the preceding claims, characterized in that it further comprises at least one locking device (5; 6) capable of locking said disc (20) in a position remote from the bottom of the socket.

8- Socket according to claim 7, characterized in that the unlocking of the locking device (5) is controlled manually.

9- Socket according to claim 8, characterized in that said locking device comprises a lever (50) pivotally mounted on a pivot (51) essentially perpendicular to the longitudinal axis of the socket, said lever comprising inclined plane (520) cooperating with an edge of a portion of the radial extension (21) associated with said locking device to pivot said lever during movement of the disc (20) under the action of the elastic means (22) as well as a flat ( 521) acting as a stop against a portion of said radial extension (21) in order to lock the disc in a position remote from the bottom of the sleeve, said lever being moreover movable in an essentially radial direction relative to the longitudinal axis of the sleeve under the action of an actuating means (510) disposed outside the sleeve, capable of sliding said lever along the radial extension until 'It arrives opposite a notch (210) of said radial extension, thereby unlocking the disc.

10- Socket according to claim 7 characterized in that the unlocking of the locking device (6) is automatically controlled during the introduction of a bulb into the socket.

1 1- socket according to claim 10, characterized in that said locking device comprises at least one lever (61) movable in a substantially radial direction relative to the longitudinal axis of the socket under the action of a means of actuation (60) disposed inside the sleeve, capable of sliding said lever along a radial extension until it arrives opposite a notch (210) or one end of said radial extension , thereby unlocking the disc.

12- Socket according to one of the preceding claims, characterized in that it further comprises a safety device (7) capable of detecting the presence or absence of the glass (32) of an electric bulb (3) on said socket and to interrupt at least the electrical circuit connecting the first contact part (120; 93) and the first contact pad (12) when it has detected the absence of said glass from an electric bulb.

13- Socket according to claim 12, characterized in that said safety device comprises at least one pusher (70) capable of sliding parallel to the longitudinal axis of the socket in a recess (1 15) of the insulating support (11), an elastic means (71) being able to push a first end (72) of said pusher out of said socket, so as to detect the presence or absence of said glass (32), the other end of said pusher being provided with a first contact means (73) cooperating with a second fixed contact means (74), said contact means closing the supply circuit of the first contact pad (12) from said first contact piece (120; 93) when said first end (72) of pusher (70) has detected the presence of a glass (32) on the socket and opening said supply circuit when said first end (72) of pusher (70) has detected the absence of a glass (32) on the socket.

14- Socket according to claim 13, characterized in that it comprises a plurality of said pushers (70) distributed around the end periphery of the socket, said contact means (73,74) of each of said pushers being mounted in series between said first contact piece (120; 93) and said first contact pad (12).

15- Socket according to one of the preceding claims, characterized in that it further comprises a housing for a micro fuse (80) disposed in the supply circuit of the first contact pad (12).

16- Socket according to one of the preceding claims, characterized in that the first contact piece corresponds to a contact terminal (120) capable of receiving a first electric supply wire and in that the second contact piece corresponds to a contact terminal (100) adapted to receive a second electrical supply wire.

17- Socket according to one of claims 1 to 15, characterized in that it is constituted by a transition socket comprising in particular an outer conductive tube (90) and an outer base base contact (93), as well as a inner conductive tube (92) and at least a first contact pad (12), the first contact piece corresponding to said base contact (93) while the second contact piece corresponds to said outer conductive tube (90).

18- Socket according to claim ^, characterized in that at least one of the outer (90) or inner (92) conductive tubes is a threaded conductive tube.

19- Socket according to one of claims 17 or 18, characterized in that at least one of the outer (90) or inner (92) conductive tubes corresponds to a bayonet base.

20- Socket according to one of claims 17 to 18, characterized in that it further comprises a locking means (900) adapted to block the transition socket mounted on another socket.

21- Luminous device provided with at least one safety socket according to one of the preceding claims.