DESCRIPTION

Field of the invention

This invention refers to the field of electric power transmission between a power supply and an electric device, in particular it concerns a method and an apparatus for the electrical and mechanical connection of a light bulb or any other electric device to a structure that can act as a mechanical support as well as a power supply.

State of the art

It is of common knowledge that the methods used for the transmission of low voltage electric power (110V,220V,380V), between a power supply and an electric device are carried out through apparatuses comprising electric contacts of one sort or another. This occurs, for example, between plugs and sockets or when fixing bulbs to lamp holders.These apparatuses differ from one another in their forms, number of contacts, their maximum values of transmittable electric current and their voltage. Even though there is a great diffusion of these existing apparatuses, they have the disadvantage that even when the electric contacts are well insulated, still a fraction of the conductive surface is exposed to the external environment. This can consequently cause accidental human contact as well as the risk of oxidation in presence of humid and harsh environmental conditions. Furthermore , the exposure of the conducting surfaces makes it impossible to use these apparatuses in electroconductive environments such as water, without using insulating materials or water tight protections which add to the total costs of the devices. One particular electric device that is effectively connected to a power supply through electric contacts is the lamp which normally consists of a light bulb and its relative lamp holder.

There are numerous different types of light bulbs that function according to different principles i.e. the incandescent bulbs or the fluorescent bulbs etc. The light bulbs are effectively connected to electric power supplies through the electric contacts present in their relative lamp holders. The mechanical coupling between the bulb and the lamp holder can be carried out in various ways such as a threaded surface, receptacles, stepping systems elastic systems etc. Another draw back of the existing bulbs is given by the fact that the above mentioned mechanical coupling necessary to guarantee a contact between the corresponding conductive surfaces, necessitates a series of operations by the user which can go from the rotation of the bulb to the forcing of a spring etc. that are not easily performed by handicapped persons.

A further disadvantage is that the existing bulbs require lamp holders endowed with electric contacts which restrict the designers' and constructors' choices in so far as the actual shape that can be given to the lamp is concerned. Summary of the invention

It is a scope of the present invention are to provide a mechanical an electrical connecting apparatus between an electrical power supply and an electrical device able to transmit electrical power without the use of electrical contacts of any sort or storage cells (batteries). Therefore it is a scope of the present invention to provide a connecting apparatus that can also be used in conductive environments without necessitating the use of special protection for the electric insulation of the contacts, since they are absent.

A particular scope of the present invention is to make available a light bulb which can be turned on merely by approaching it to its lamp holder. A further particular scope of the present invention is to provide a light bulb with no electric contacts or conductive surfaces exposed in order to completely insulate the bulb from its external environment.

Another particular scope of the invention is to provide a light bulb able to avoid any accidents even if contact should occur with the user. It is a further particular scope of the invention to make available a lamp that can be directly used in water or any other electroconductive environment with no need of further protection because it is electrically insulated.

Moreover it is a scope of the present invention to provide a light bulb that requires no particular effort when it must be installed or substituted as it is sufficient to approach the bulb to the lamp holder to turn it on. In this aspect it is particularly suitable for handicap bearing people. According to another scope of the present invention it is provided a light bulb that does not require a lamp holder with electric contacts for electric input and can therefore be shaped and designed as desired.

A further scope of the present invention is an electrically insulated light bulb with an outer shell made of soft and flexible material that can also be used in children's toys.

The above mentioned goals can be achieved by a direct electrical and mechanical apparatus connecting an electric power supply to any electric device with no need of batteries and comprising:

- a primary element connected to an electric power supply , provided with a primary electric winding consisting of a variety of coils that create a primary magnetic field;

- a secondary element, connected to the electric device endowed with a secondary electric winding made of a variety of coils that transform the variable primary magnetic field into an electric current which in turn powers the appliance. said primary and secondary elements being releasable and coupled in such a way that when in use, the variable primary magnetic field runs through the axis of the secondary winding said elements being electrically insulated and therefore capable of interacting exclusively through the magnetic field. The electric power transfer is thus made possible without electric contacts of any sort. The above said primary electric winding and the above said secondary electric winding respectively coil around a primary ferromagnetic nucleus called the primary element and a secondary ferromagnetic nucleus called the secondary element. The above mentioned nuclei being aligned at a relatively minimal distance when the secondary element couples with the primary element. Alternatively, the primary electric winding coils around a ferromagnetic nucleus which protrudes from one side of the winding. This protruding portion actively

couples with the secondary winding. In this manner the primary element can be said to function as a plug while the secondary element as a socket.

According to another embodiment of the invention the secondary electric winding coils around a ferromagnetic nucleus which protrudes from one side of the winding. This protruding portion actively couples with the primary winding. In this manner the primary element can be said to function as a socket plug while the secondary element as a plug.

Alternatively the primary electric element has a flattened form and contains the primary winding as well as the disc formed ferromagnetic nucleus. In a further embodiment of the invention, the primary element is contained in a box which is built into a wall and levelled to the surface of the latter, the primary element is therefore inconspicuously integrated into the decoration.

According to a further embodiment of the invention, the primary element comprises a "C" formed ferromagnetic nucleus and the secondary element comprises a ferromagnetic nucleus shaped to create a closed magnetic circuit together with the primary ferromagnetic nucleus.

If preferred, the primary element is endowed with means that can easily fix and release the secondary element.

In particular the above said fixing means comprise permanent magnets that are an integral part of the primary and secondary elements and are positioned to face one another once in use.

According to a preferred embodiment of the invention the connecting device comprises a switch that closes the primary winding when the secondary element is coupled to the primary element. A particular switch is a switch of a magnetic type, for example a "reed switch", which is actioned by the permanent magnets which are part of the secondary element.

In a preferred embodiment the primary element is contained in a lamp holder and the secondary element in a light bulb which comprises a closed electric circuit provided with:

- at least one light emitting element which emits light once powered by an electric current;

- a secondary electric winding, connected to the lighting element , comprising a plurality of coils which transform the variable external magnetic field into an electric current which then runs through the winding and the lighting element;

- an insulating external shell that completely envelopes the secondary winding and the bulb; the bulb being devoid of any external contacts.

In particular, the variable external magnetic field is generated by the primary electric winding situated in the lamp holder which thus not only acts as a mechanical supporting base for the bulb but is also able to power the bulb by electric induction. The light emitting element can be: a filament lamp; a fluorescent lamp; a LED. When the bulb consists of fluorescent lamp, the light emitting element is provided with an electronic circuit which transmits a tension and current of appropriate frequency to the gas. The position of the electronic circuit is chosen among the following: Inside the light bulb; Within the lamp holder;

In a central position outside the bulb and the lamp holder. Preferably, the above said insulating external shell contains the closed circuit, the winding and the light emitting element. A further embodiment of the invention the secondary element is directly connected to the motor of which the electric device is possibly equipped (i.e. the motor of a mixer) and preferably said secondary element and said motor to which it is connected are electrically insulated and form a single block from which only the rotor protrudes, thus allowing the necessary movements of the active parts of the electric device.

In this case, the primary element will therefore be positioned in the supporting base of the electric device (connected to a power source by the usual connecting instruments such as an electric wire and its relative plug) while the motor/secondary circuit block will be englobed in the part of the electrical device that carries the mobile parts, the rotor will protrude from the electrically insulated block in order to engage in the usual way with the sustaining part of the electrical device that carries the active mobile parts. In the above mentioned case the

sustaining part that carries the active mobile parts is the tumbler of the mixer while the active mobile parts are the blades and the other accessories of the mixer).

Even in this case the advantages of using the apparatus are quite obvious as it is possible to remove the mobile parts of the appliance (for example for washing) without running the risk of a possible contact or short circuit. Moreover the connection between the base and the mobile part is facilitated.

Brief description of the drawings.

The invention will be illustrated as follows with the description of some of the forms it can take. The annexed figures will serve as examples and will in no way be restrictive in the use and the realisation of the device.

Figure 1 shows the cross section of a bulb according to the invention, connected to its corresponding lamp holder that has only one ferromagnetic nucleus common to both the primary and secondary windings; Figure 2 illustrates a blown up figure of one way in which the bulb shown in diagram 1 can be realised;

Figure 3 shows a cross section of the bulb of figure 2;

Figure 4 represents a particular scheme of the magnetic field used by the bulb according to this invention; Figure 5 illustrates another form in which the bulb can be realised following the invention. In this case the ferromagnetic nucleus is divided in two parts; one being part of the bulb and the other part of the lamp holder;

Figure 6 shows the cross section of a bulb and a lamp holder of figure 5 (the bulb is not fitted into the lamp holder); Figure 7 the lines of the magnetic field which interests a ferromagnetic field divided in two parts as shown in figures 5 and 6;

Figure 8 illustrates a lamp in perspective. It is formed by a bulb and a lamp holder according to the invention (the lamp holder is fixed to a wall);

Figure 9 shows the cross section of the lamp as illustrated in figure 8; Figure 10 represents a further way of following the invention in realising a lamp. In this case the corresponding lamp holder is built in the wall;

Figure 11 shows a lamp holder in a standard box, built in a wall;

Figure 12 represents the cross section of a lamp as shown in figure 10 together with its lamp holder as shown in figure 11 ;

Figure 13 demonstrates how the present invention can be applied in the realisation of a table lamp; Figure 14 illustrates the cross section of a lamp as in figure 13 with its bulb fitted into the corresponding lamp holder;

Figure 15 shows the cross section of a lamp as in figures 13 and 14, wherein the bulb is not yet fitted into the relative lamp holder;

Figure 16 is a perspective view of the invention's electrical and mechanical apparatus connecting an electric power supply and an electrical device;

Figures 17 to 19 show the cross section of the above mentioned apparatus;

Figure 20 schematically illustrate the cross section of the apparatus in question endowed with a magnetically actioned switch within its relative primary element.

Description of preferred embodiments of the invention. In the following description reference is made, as a particular example of the invention, to an electric bulb which can be switched on by using the induced current from an external field into an electric circuit contained in the bulb. The above mentioned magnetic field is generated by an electric winding positioned in the lamp holder. Figures 1 to 3 represent a bulb realised according to the invention. The lamp holder 20 contains a primary winding made up of a number of coils winded, in the form of a solenoid, around a central zone which contains a ferromagnetic nucleus

4.

A secondary winding 2 contained in the bar hold 14 of the bulb 10 is capable to be crossed by the magnetic field generated by the primary winding 1 , and will therefore supply the necessary electric power to switch on the light emitting element 12.The bulb 10 and the lamp holder 20 are held together by the force of attraction created between the magnets 16 and 23. Both the windings 1 and 2 are enveloped in the respective insulating materials 14 and 15, and therefore cannot come into contact.

Figure 2 illustrates how the ferromagnetic nucleus 22 protrudes from the lamp holder 20 and couples with the bulb 10.

In the case shown in the figures , a low consumption light emitting element 12 is used, note that in order to function, the light emitting element requires also a connecting wire 17 and an electronic circuit 13 known as "ballast" contained in the bulb 10. The insulating materials 14 and 15 disposed between the nucleus and the windings 1 and 2 reduces the efficiency of the inductive power transmission in an insignificant measure.

Figure 4 specifically shows the functioning of the fig.1 to 3 bulb, according to the known principle in which an alternative magnetic field which runs through a secondary winding 2 along its axis, generates in the winding 2, an alternating tension which can thus be used by the device once it is electrically connected to such winding 2, thereby forming a closed circuit. In the figure, the magnetic field 3 is generated by a primary winding 1 and its lines of force are aligned and conveyed into the two windings by means of the ferromagnetic nucleus 4. All electric connections between the first and second circuits are thus eliminated. Figures 5 and 6 illustrate a light bulb containing a ferromagnetic nucleus 5 which is an integral part of the bulb 10 separated from another ferromagnetic nucleus which is an integral part of the lamp holder 20. A variable magnetic field, not shown in the figure, is generated from the winding 1 and runs through the ferromagnetic nucleus 5 and the secondary winding 2, both integral parts of the bulb, providing thus the electric current to the lighting element 12 through the conductors 17 and the "ballast"

13.The latter has been drawn inside the bulb but it can obviously be located in a central position and used by a plurality of devices. In such a case, each lamp holder provides a magnetic camp which directly feeds the lighting element.

Figure 7 illustrates the functioning of the bulbs in the figures 5-6, which follow the known principle of mutual magnetic induction illustrated in figure 4. Here the two windings 1 and 2 are respectively coiled around two distinct ferromagnetic nuclei 4 and 5. This way the effect induced on the secondary winding is reduced insignificantly compared to the one obtained in the case shown in figure 1 and is therefore sufficient for the purposes of the present invention.

Figures 8 and 9 show a further embodiment of the invention. In particular figure 8 illustrates the cross section of a bulb 10 and its lamp holder 20 fixed to a wall 30. The bulb 10 has an outer shell in form of a prism 11. Figure 9 illustrates a cross section of the above mentioned bulb 10 with its lamp holder 20 which assumes a flat form and contains a primary winding 1 coiled around a ferromagnetic nucleus 4. The bulb 10 comprises a secondary winding 2 coiled around the ferromagnetic nucleus 5, and a lighting element 12.The bulb 10 adheres to the lamp holder 20 by the action of the two magnets 16 and 23, respectively parts of the bulb 10 and the lamp holder 20. Figures 10 to 12 represent the case in which the lamp holder is built into the wall and therefore as shown in figure 10, only the bulb 10 is visible while the lamp holder stays hidden in the wall 30, behind the lamp 10.

Figure 11 shows the relative lamp holder 20 which is fitted in a box 41 and has a support plaque 24 fixed to the former, a primary winding 1 indicated in the figure by a dotted line, a ferromagnetic nucleus 4 and the magnets 23 which keep the bulb (not shown in the drawing) in place by acting on the corresponding magnets (not shown in the drawing).

Figure 12 illustrates in cross section the fitting of the light bulb 10 to its respective lamp holder of figure 11. As in the former case the bulb 10 comprises a secondary winding 2, a ferromagnetic nucleus 5 and a lighting element 12.

Figures 13 to 15 show how the present invention can be carried out in realising a table lamp made of bulb 10 with its lamp holder 20. The latter has a cavity 50 where bulb 10 can be housed and its portion of the ferromagnetic circuit 4 is closed by the ferromagnetic nucleus 5 contained in bulb 10. A primary winding is coiled around said portion of circuit 4 and a secondary winding 2 is coiled around the nucleus 5.

It should be noted that in the figures above, the light bulb has been schematically illustrated with a fluorescent tube as its light emitting element. It is however obvious that the other realisations, as previously described, are possible. Figures 16 to 19 show in a more general manner an electrical and mechanical connecting apparatus according to the invention.

This apparatus comprises a primary element 100, which functions as a socket, connected to a power supply and a secondary element 101, which acts as a plug, connected to an electric appliance. In the example shown in figure 16, the item

100 is built in a wall with only its plaque 103 visible , and as the latter contains no holes or cavities its use and/or cleaning is extremely safe.

Figure 17 illustrates the cross section of the connecting device in which element

101 is linked to element 100. Element 100 is fitted into a box 41 and built into a wall. The box contains the primary winding 1 , coiled around a ferromagnetic nucleus 4. This winding generates a magnetic field , not shown here, with its lines of force which perpendicularly run through the above mentioned plaque 103. Element 101 contains a secondary winding 2 coiled around a ferromagnetic nucleus 5 which stays actively aligned with the primary ferromagnetic nucleus 4 so that the lines of the magnetic force generated by element 101 cross the axis of the ferromagnetic nucleus 5. The transmission of electric current between elements 100 and 101 is carried out by mutual electromagnetic induction. Element 101 is maintained in the correct position through the action of the permanent magnets 16 , contained in element 101 , and 23 contained in the plaque 103 of element 100. Figure 18 illustrates the transversal cross section of the apparatus according to the invention. In the cross section of element 100 permanent magnet 16 can be distinguished. The latter has a circular crown like form and is fitted into the plaque 103 along with the primary electromagnetic nucleus 5. Part of the outer shell of element 101 can also be seen. Furthermore , figure 19 shows elements 100 and 101 not yet connected to one another.

Figure 20 schematically represents a connecting device whose primary element 100, which has a supporting function, contains a magnetically actioned switch 105 (reed switch) which closes the circuit when the secondary element 101 is placed in front of the above mentioned primary element. This way the magnetic switch 105, which is normally open, closes the input to the primary winding 1 only when the secondary element is in an operative position. This consents energy to be saved when no electrical devices is connected.

The above description of a specific procedure in realising the invention is purely illustrative and can therefore be adapted and or modified by integrating the already known and commonly used technology.

Moreover the means and materials employed for carrying out the described functions can also vary without modifying the nature of the invention.

In other words the expressions and terminology used here have a purely descriptive function and do not intend to be restrictive in any way.