WO2019016712A1

WO2019016712A1 - Electric socket with switch

Info

Publication number: WO2019016712A1
Application number: PCT/IB2018/055316
Authority: WO
Inventors: Pietro MALANCA; Arturo IOSSA FASANO
Original assignee: 4 Box Srl
Priority date: 2017-07-20
Filing date: 2018-07-18
Publication date: 2019-01-24
Also published as: GB2578849B; GB2578849A; IT201700082695A1; GB202000575D0

Abstract

An electrical socket (10) comprises a housing (11) with a front face (12) provided with holes (13) which are intended to receive, axially inserted therein, pins of an electric plug. At least some holes (13) have, arranged behind them, first electrical contact elements (24, 26) intended for electrical contact with the pins of an electric plug inserted in the holes (13) and the socket also comprises electric terminals (21, 23) intended for connection of a power supply for the electrical contact elements (24, 26). The electrical contact elements (24, 26) are supported by a frame (17) which is present inside the housing (11) and which is movable, between a first position and a second position, in a plane transverse to the direction of axial insertion of the pins inside the holes (13). In one position the first electrical contact elements (24, 26) are electrically connected to the respective electric terminals (21, 23) and in the other position at least one of the electrical contact elements (24, 26) is electrically isolated from the respective electric terminal (21, 23). In this way the movement of a plug in the socket causes activation or deactivation of the plug power supply.

Description

"Electric socket with switch"

The present invention relates to an electrical socket which incorporates an electrical switch. In particular, the socket may be of the modular type, namely may be engaged in a mounting frame in an electrical installation, optionally together with other modular electrical components (for example other sockets, switches, pushbuttons, etc.).

The socket may also be advantageously a socket of the "multi-standard" type, namely an electrical socket which allows the alternative connection of two or more types of different plugs for connection to the electricity mains.

In the sector of electrical sockets occasionally the need arises to be able to interrupt in a controllable manner the electric power supply to the socket. For this purpose, usually the socket is connected to the electrical installation by means of a suitable electric switch. For example, it is possible to arrange a modular socket and a modular switch next to each other on the same mounting frame and perform the suitable electrical connections between them and with the electrical installation.

Electrical sockets provided with an incorporated switch have also been proposed. In these sockets, the switch (already connected inside the socket in order to perform the controlled de- energization of the socket) is arranged alongside the socket zone where the associated plug is engaged and allows the power supply to the electric plug to be interrupted without having to remove the plug from the socket by simply manually operating the switch lever. Such a type of socket is for example widely used in the UK.

In the known designs, the switch arranged alongside the socket (both separately and incorporated inside it) results, however, in a wastage of space which is not always acceptable and major constraints when mounting the socket in an installation.

For example, where the switch is required in order to interrupt the power supply to the socket and the space is not sufficient to house two modules arranged next to each other, it is not possible to contemplate the use of modular sockets which instead could be advantageous from an aesthetic, operational and cost point of view.

The problem is even further complicated in the case of sockets which by nature have a bulky design: this is the case, for example, of electrical mains sockets with an earth contact which is not aligned with the power supply contacts. For example, the German sockets or so-called "schuko" sockets and British sockets have a width which is twice that of a standard module, such that the modular sockets of this type occupy already the width of two standard modules and it is not always possible to arrange a switch module alongside these.

In the case of sockets with an incorporated switch it is instead not possible to limit the dimensions of the socket to those of one or two standard modules, because it is always required to provide an additional space for the manual operating lever of the switch which must be located next to the zone where the plug is engaged in the socket.

For example, in the UK each socket has an associated switch which allows the connected device to be switched off without disconnecting the plug. Since the wall-mounted boxes used in British electrical installations generally are small in size it is not possible to use modular systems which instead are standard in other countries, and this results in major drawbacks from a cost point of view.

US 5484299 A describes a socket provided with an incorporated switch which is operated by means of axial rotation of the socket. This results, however, in a structure which is weak and not very safe and not suitable for forming a modular socket. Moreover, the rotational movement means that the front visible face of the socket must be designed so as to be fully rotational, with further problems in terms of strength and reliability. The rotational movement also twists the cable of the plug and, in the case of angled plugs, may also be difficult to perform. The weight and twisting of the cable, in particular in the case of angled plugs, but also in other cases, may also generate a rotational torque which tends to trip the switch of the socket, causing it to open or close, with the consequent risks of unintentional or unreliable operation of the electrical contacts.

The general object of the present invention is to provide a socket which is equipped with an incorporated switch, but which has small dimensions preferably equivalent to those of a normal socket without switch, while also overcoming the drawbacks of the prior art.

In view of the above object the idea which has occurred, according to the present invention, is to provide an electrical socket according to claim 1.

In order to illustrate more clearly the innovative principles of the present invention and its advantages compared to the prior art, an example of embodiment applying these principles will be described below with the aid of the accompanying drawings. In the drawings:

- Figure 1 shows a perspective view of a possible embodiment of a socket according to the invention;

- Figure 2 shows a socket according to the invention with a conventional plug inserted;

- Figure 3 shows a perspective view of the socket according to Figure 1 with a top part removed;

- Figure 4 shows a perspective view, similar to that of Figure 3, but with the socket in a different operating condition;

- Figures 5-8 show perspective views, similar to that of Figure 1, with the socket, which is designed as a multi-standard socket, engaged by different types of plugs;

- Figures 9 and 10 show front perspective views of the socket according to Figure 1 in two different operating conditions with a side part of the housing partially removed;

- Figures 11 and 12 show rear perspective views of the socket according to Figure 1 in two different operating conditions with a side part and rear part of the housing partially removed;

- Figures 13 and 14 show partially cross-sectioned, lateral, perspective views of the socket according to Figure 1 in two different operating conditions.

- Figures 15, 16 and 17, 18 show a perspective and plan view, respectively, of contact elements of the socket according to Figure 1 in two different operating conditions;

- Figures 19, 20, 21 and 22 show further partially cross-sectioned, lateral, perspective views of the socket according to Figure 1 in two different operating conditions.

With reference to the figures, Figure 1 shows an electrical socket - denoted generally by 10 - designed in accordance with the invention.

The socket 10 comprises an outer housing 11 with a front face 12 provided with openings or holes 13 which are intended to receive, axially inserted therein, the pins of an electric plug. As will be clarified below, at least some of these holes have, arranged behind them, electrical contact elements (for example three contact elements 24, 25, 26) which are intended to make electrical contact with corresponding pins of an electrical plug engaged in the socket. For example, the contact elements may be divided into two contact elements 24, 26 for the power supply and one contact element 25 having an earthing function. The earthing contact 25 may also be optional, depending on the type of plug to be connected, as will be clarified below. As will become clear below, the socket may also comprise a suitable internal safety device or shutter 41, known per se, which is movable in a resilient manner between a position for closing and a position for opening at least the holes which have inside them electrical contacts crossed by a potentially dangerous electric voltage (for example two contacts connected to a single-phase mains voltage). The movement between the two positions may be performed by the simultaneous introduction of the pins of a plug into these holes. Essentially this safety device has a dividing member which is positioned between the inlet holes and the rear-lying electrical contacts so as to prevent a foreign body (for example, a pointed metal object or a child's finger) from being accidentally inserted in one of the holes and making contact with the internal electrical connections. Figure 2 shows by way of example a possible electric plug 16 engaged with the socket 10. The socket may be advantageously designed with a modular and generally parallelepiped form and be able to be engageably mounted on a support frame 14, generally known per se and therefore able to be easily imagined by the person skilled in the art. For mounting on the frame 14, the socket 10 may comprise engaging elements 15, known per se, located for example on its opposite side faces. The engaging elements 15 may be of any known type (for example teeth or seats for the interlocking insertion of complementary elastic lugs) for example used for mounting modular elements of an electrical installation in special frames or boxes.

As can be seen for example in Figure 11, the socket may further comprise electrical terminals 21, 22, 23 which are intended for connection to an electrical installation, for example to electric wires of an electrical installation (not shown). In the same way as for the electrical contact elements, at least two electric terminals are required for the socket power supply, while another terminal may or may not be present, depending on whether or not the earthing contact 25 is provided.

As can be clearly seen again in Figure 11 , the electric terminals (for example the terminals 21, 22 and 23) may be advantageously designed so as to provide a connection with a screw-type clamp. In order to achieve this, each terminal may comprise a seat (for example 27, 28, 29 respectively) for inserting the stripped end of a respective electric wire and a corresponding clamping screw (for example screws 30, 31, 32).

Figure 3 shows the socket 10 with, removed, the housing part 11 which forms the front face 12 provided with holes, so as to reveal a frame 17 which is present inside the housing 1 1 and which contains or in any case supports the electrical contact elements of the socket. The frame may be advantageously box-shaped, for example have a general parallelepiped form, with holes opposite the contact elements and underneath the holes 13 of the face 12. As will become clear below, the bottom part of the frame may be at least partially open at the rear of the contact elements.

Figure 3 also shows by way of example (cross-sectioned) three pins 18, 19, 20 of a plug inserted in the socket so as to make contact with the contact elements inside the frame 17. As can be clearly seen from the figures, the frame 17 is movable and, in particular, slidable inside the outer housing 11 in a rectilinear direction in a plane transverse to the direction of axial insertion of the pins inside the holes so as to be able to be controllably displaced between a first position (shown in Figure 3) and a second position (shown in Figure 4).

In the first position the electrical contact elements are electrically connected to the respective electric terminals, while in the second position at least one of the first electrical contact elements is electrically isolated from the respective electric terminal in order to perform interruption of the power supply.

The movement of the frame 17 between the first position and the second position is advantageously performed by the corresponding displacement in the transverse direction (with respect to the pins) of a plug engaged in the socket, acting substantially on the frame and/or on the contact elements through the holes 13.

In this way, the socket according to the invention does not require a separate switch with associated operating lever, but it is merely required to displace the plug in the sliding direction of the frame 17 after engaging it in the socket.

The movement may be advantageously a translational movement as shown in the example of the drawings.

Preferably, the front face 12 forms part of the outer housing and not of the frame 17, such that the front face does not move together with the plug and the frame 17 slides behind the front face 12. In this case, the holes 13 have a suitably elongated form in the direction of movement, so as to allow movement of the plug together with the frame 17. Advantageously, the holes 13 and the underlying electrical contact elements 24, 25, 25 may be designed so as to accommodate sockets of different types, so as to form a multi-standard socket. In particular, the holes and the contact elements may be formed so as to be able to receive at least one plug of a first type and, alternatively, at least one plug of a second type differing from each other in terms of cross-section and/or arrangement of the pins.

For example, Figures 3, 5, 6, 7 and 8 show the pins (for convenience all indicated by the same numbers 18, 19, 20) respectively of plugs used in the US, China, Europe, India and the UK and all able to be engaged with the socket shown, which is therefore designed as a multi- standard socket. In order to receive these plugs, the socket has the holes and the underlying contact elements generally arranged at the vertices of a triangle, i.e. with the earth contact which is not aligned with the two contacts. Obviously, other types of plugs may be engaged with a socket according to the invention by providing the holes and the contact elements with forms and positions corresponding to the plug or plugs which are to be used, as may be now easily imagined by the person skilled in the art.

For example, if not required, the contact element and the corresponding electric terminal used for earthing may be dispensed with or may also be replaced by different earth contact systems, such as the two lateral spring strips used in the known schuko sockets.

Figures 9 and 10 show the socket 10 with a side part of the outer housing 11 which has been removed in order to reveal the inner frame 17. In Figure 9, the frame is in the first position, corresponding to the condition where the plug is not powered (switch OFF), while Figure 10 shows the frame in the second position, corresponding to the condition where the plug is powered (switch ON).

As can be clearly seen in Figures 11 and 12, at least one of the two contact elements 25,26 has an electrical contact area 33 which is intended to rest on a corresponding electrical contact area 34 of the corresponding connection terminal 23, when the frame 17 passes from the first position (OFF position) shown in Figure 11 to the second position (ON position) shown in Figure 12.

Preferably, both the contact elements 25, 26 and the corresponding terminals are formed (advantageously in a mirror arrangement) such that in the OFF position of the socket both the contact elements are electrically isolated from the respective electric terminals. A bipolar switch is thus formed.

Figures 13 and 14 show a central cross-section through the socket 10, in the first position and second position, respectively, of the frame 17.

In these figures it can be clearly seen that, advantageously, the contact element 25 for the earth connection is formed with a contact surface 35 which extends along the direction of sliding movement of the frame 17 so as to be always in electrical contact with at least one corresponding contact end 36 of the electric terminal 22, so as to form a sliding contact which allows the earth electrical connection to be always maintained with the contact element 25 even when the socket is in the OFF position. This ensures a greater level of electrical safety owing to the fact that an electrical apparatus connected to the socket is kept connected to earth even when the plug is displaced into the OFF position.

Figures 13 and 14 also clearly show a resilient snap-engaging mechanism 37 for stably maintaining the two ON and OFF positions of the socket. This mechanism comprises advantageously a resilient - for example metallic - strip 38 which is fixed (for example force- fitted) inside the outer housing and on which a tooth 39 of the frame 17 may slide, passing over a ridge 40 in the strip which separates the two stable positions.

For greater clarity, the electrical contact elements 24, 25 and 26 and the corresponding electric terminals 21, 22, 23 are also shown separately in Figures 15, 16 and 17, 18, so that relative contact movement is more clearly illustrated.

In these figures, a possible configuration of the part of the electrical contact elements which forms the surfaces for making resilient contact with the various pins of the plugs can be clearly seen. The contact elements may be made as a suitable resilient strip which is cut and folded, as may be easily imagined by the person skilled in the art.

As can be clearly seen in the figures, the earth contact 25 may advantageously have a cross- section (in the direction of sliding movement of the frame) which is U-shaped, with ends of the arms of the U which are directed towards the hole for inserting the earth pin of the plug so as to form two shaped resilient contacts which receive on opposite sides the earth pin of the plug engaged in the socket. The bottom of the arms of the U form instead the sliding surface 35 for the contact 36. In this way, the entire earth contact is made using a piece of strip-like metal which is suitably cut and shaped. The arms of the U may be easily shaped in order to receive different types of pin, as clearly shown in Figures 15 and 16.

Again as can be clearly seen in the figures, the contacts 24 and 26 may have a general (reshaped section in the plane transverse to the direction of insertion of the pins, with resilient arms which project from the C towards the holes for insertion of the pins of the plug so as to form shaped resilient contacts which receive a corresponding pin of the plug inserted in the socket. These resilient contacts may be advantageously three in number, as can be seen in the figures, two arranged opposite each other and one transverse thereto, so as to receive different types of pin.

As can be clearly seen in Figures 15 and 16, one of the arms of the C also advantageously forms the contact 33 of the switch. The corresponding contact 34 may be formed by means of a C-shaped metal strip, with one arm of the C which forms the contact 34 and the other arm of the C which is connected to a block which forms the terminal 21 or 23, advantageously a clamping screw as described above.

This structure is simple and low-cost, easy to assemble and strong.

Figure 19 shows a cross-section along a plane passing through a contact 24 in order to show in greater detail the safety device or shutter 41. The shutter 41 comprises inclined surfaces 42 which are arranged immediately below the two holes 13 and which protect the contacts 24 and 26 from the outside. The shutter 41 is resiliently retained in the protection position shown in Figure 19, for example by means of a spring or resilient tongue, not shown). The shutter is designed so that it cannot slide laterally if only one inclined surface is acted on by the thrust of an object towards the inside of the socket.

As can be seen in Figure 20, when the two pins 19,20 of a plug are simultaneously inserted, the pins push on the two inclined surfaces of the shutter so as to displace it laterally and allow the pins to pass through and thus make contact with the underlying contact elements 24 and 26. If the plug is removed, the shutter returns elastically into its protection position shown in Figure 19.

Once the plug has been inserted, the frame 17 may be displaced into the ON position, as shown in Figure 21.

The shutter 41 is advantageously supported in the frame 17, so as to move together with it and maintain its relative position with respect to the underlying contact elements.

As can be seen in Figure 22, also when the frame is in the ON position, if the plug is removed the shutter returns elastically into its protection position.

At this point it is clear how the predefined objects have been achieved. A socket designed in accordance with the principles of the present invention is able to provide the function of a controlled switch without this switch occupying space on the front of the socket or the need for a separate switch and/or a separate switch control function. Moreover, the sliding frame which supports the contacts is advantageously completely contained within the outer housing and this makes the assembly very strong and reliable over time. The contact elements and in general all the electrically conductive parts of the sockets have small dimensions so that they have a limited cost even though made so as to obtain optimum electrical properties and therefore using materials and/or production methods which are relatively costly, as known to the person skilled in the art.

Obviously, the above description of an embodiment applying the innovative principles of the present invention is provided by way of example of these innovative principles and therefore must not be regarded as limiting the scope of the rights claimed herein.

For example, as mentioned above, the plugs which can be used may be different from those shown, by means of modifications to the socket which may now be easily understood by the person skilled in the art, in order to adapt them to specific requirements of a mains power supply installation, for example depending on the country and the product range used in the installation. The number of contact elements and their form may also vary depending on the number and form of the pins of the plugs which are to be connected. The movement of the frame between the ON position and the OFF position may also be a rotational or rotary translational movement instead of a pure translational movement.

Moreover, the socket shown in the figures is advantageously of the modular type, namely is formed as a module for use together with other components of an electrical installation, but may also be designed for separate use or for use in electrical apparatus, as may now be easily imagined by the person skilled in the art. For example, the socket may form part of a multiple socket, namely a device provided with a plurality of sockets arranged alongside each other for mobile use or use in a fixed installation.

Claims

1. Electrical socket (10) comprising a housing (11) with a front face (12) provided with holes (13) intended for the axial insertion therein of pins of an electric plug, at least some of the holes (13) having, arranged behind them, first electrical contact elements (24, 26) intended for electrical contact with the pins of an electric plug inserted inside the holes (13), the socket further comprising first electric terminals (21. 23) intended for connection of a power supply for the electrical contact elements (24, 26), characterized in that the first electrical contact elements (24, 26) are supported by a frame (17) which is present inside the housing (11) and which is slidable, between a first position and second position, in a rectilinear direction in a plane transverse to the direction of axial insertion of the pins inside the holes (13), in one position the first electrical contact elements (24, 26) being electrically connected to the respective electrical terminals (21, 23) and in the other position at least one of the first electrical contact elements (24, 26) being electrically isolated from the respective electric terminal (21, 23).

2. Socket according to claim 1, characterized in that the movement of the frame (17) between the first and second position is performed by the displacement of a plug with the pins inserted inside the holes (13) and moved in said rectilinear direction.

3. Socket according to claim 1, characterized in that said first contact elements (24, 26) are at least two in number and in the second position both of them are electrically isolated from the respective electric terminals (21 , 23).

4. Socket according to claim 1 , characterized in that, behind the holes (13), a further contact element (25) is provided, stably connected to a further electric terminal (25) which is intended for an earth connection.

5. Socket according to claim 1 , characterized in that at least one electrical contact element (24, 26) comprises a contact area (33) which is movable so as to rest against a corresponding contact area (34) of the corresponding electric terminal (21 , 23) upon displacement of the frame (17).

6. Socket according to claim 1 , characterized in that the electric terminals (21, 22, 23) are in the form of clamps which face outwards from the housing in order to receive the ends of stripped electric wires.

7. Socket according to claim 1 , characterized in that it comprises engaging elements (15) intended to engageably mount the socket on a frame or in a supporting box.

8. Socket according to claim 1 , characterized in that the holes (13) and the contact elements (24, 25, 26) have a form suitable for receiving pins of at least one plug of the first type and, alernatively, of at least one plug of the second type which differ from each other in terms of cross-section and/or arrangement of the pins, and for making contact with these pins.

9. Socket according to claim 1, characterized in that it comprises a safety device (41) which is movable between a position for closing and a position for opening at least some holes (13) upon simultaneous introduction of pins of a plug inside said at least some holes.

10. Socket according to claim 1, characterized in that the holes (13) are three in number, arranged at the vertices of a triangle.