The present patent concerns electrical devices and more specifically it concerns an adapter for electric plugs for civil use and industrial sockets.
Electrical plugs for use in civil buildings are known, both of the Schuko type and of the Italian type with three aligned pins, which are commonly used to connect to the power mains household appliances such as vacuum cleaners, air conditioners, refrigerators, and so on, as well as tools such as drills, electric saws or any other electric tool needed for different applications in civil buildings where corresponding sockets are provided. Industrial plugs and sockets are also known, which are safer, so that they can be used both indoors and outdoors, as they can be exposed to weather agents.
These industrial plugs and sockets usually comply with the European standard EN 60309-1.
If said electric tools or appliances need to be used both in domestic and in industrial environments, it is necessary to modify the plug, so that it is suitable for use both with sockets for civil buildings and with industrial single-phase sockets.
It is also known that it is not possible to modify the plug of an electrical device or of an electrical piece of equipment in general, for example a household appliance or a tool such as a drill, since the removal of the plug voids the manufacturer's guarantee.
For this reason, professional operators, who use their equipment both in civil and in industrial environments, are forced to use two different devices or to resort to special adapters which are not always used correctly.
The known adapters are made up of a main body, provided with a front portion comprising the pins that are typical of standardized industrial plugs and with a socket for the insertion of a plug of the type for civil applications in the rear portion.
Furthermore, said adapters are covered by shells intended to protect the contacts according to the currently applied standards for industrial plugs and sockets.
The patent
More specifically, the shell is constituted by two half-shells suited to be constrained to each other in order to define the protective shell, which is provided with an opening for the passage of the power cable with the electrical plug at the level of the rear end opposite the one intended to be coupled with the plug body. Said half shells are furthermore provided with through holes for the insertion of tightening screws. Said holes for the insertion of tightening screws are distributed on said half shells both on the end intended to be coupled with the plug body and on the opposite end provided with an opening for the passage of the power cable.
The assembly of said half shell thus requires the use of specific tools and tightening screws, which must be used in order to ensure the tightness of the shell.
The patent
The document explains that a nut is used in order to fix the half shells to each other, said nut consisting of an internally threaded circular body suited to be screwed on the threaded ends of said half shells. Therefore, in order to obtain the connection, it is necessary to previously fit the nut on the cable, and the nut cannot be removed any more without disassembling the plug.
The opposite ends of said half shells, instead, are constrained to the body of the casing, for example by means of an adhesive material or by simply juxtaposing them. The use of an adhesive material does not allow the half shells to be joined and separated when necessary, while their simple juxtaposition does not ensure tightness.
The patent
This type of cable clamps always requires the use of an interposed elastic element forming a sealing ring.
It is the object of the present invention to provide an adapter that complies with the European standard and can offer the required degree of safety.
It is another object of the present invention to provide an adapter that can be easily applied and removed without using tools, such as pliers or screwdrivers, etc., in order to favour the double use of the plug for civil applications.
It is another object of the present invention to guarantee the perfect adhesion of the plug to the inner socket, in order to ensure that the adapter can be extracted from the industrial socket without disconnecting the plug from the socket.
It is another object of the present invention to provide an adapter in which both the annular part and the edges of each half shell are tight as required by the regulations in force.
For this reason, a new adapter has been designed, which among its main parts includes a centre body and at least two or more half shells that are suited to be connected to one another in order to obtain a tight chamber, and wherein said shells, once the plug for civil applications has been inserted in them, are locked at the rear by screwing a threaded ring nut in the shape of a cap or a dome thereon, and wherein said threaded ring nut guarantees that the plug cable is locked and that said half shells are tight.
In further detail, said half shells, which once joined form said closed chamber enclosing the plug, have a first end suited to be constrained to the centre body and a second opposite end, from which the cable exits and which is externally threaded in order to ensure that said threaded ring nut, in turn consisting of at least two complementary parts suited to be connected to form the ring nut itself, can be screwed thereon.
Said first end of the half shells is configured in such a way that it can be hinged to said centre body or at least partially inserted in said centre body or is both hinged to and at least partially inserted in said centre body.
An important aspect of the new adapter lies in that the connection of said half shells to the centre body is of the reversible type, does not require the use of screws or adhesive materials and furthermore, thanks to the special configuration of said first end of the half shells, guarantees tightness.
Said second end, instead, is especially configured with an external thread for screwing said ring nut that can be directly mounted around the cable, thus with no need to remove the plug. Furthermore, said second end is configured with inner hooks that act directly on the cable and that, due to the tightening of the ring nut, clamp the cable and prevent it from coming off.
The characteristics of the new adapter are highlighted in greater detail in the following description, with reference to the attached drawings that are enclosed hereto by way of non-limiting example.
The new adapter comprises a main body A, in turn comprising a circular wall A1 designed to protect the pins suited to be inserted in plugs of the industrial type, a stop ring A2, a cylindrical centre body A3 containing the plug A5, which can be of the Schuko type or of the Italian type with aligned holes or of the universal type or of any other standard type for civil applications.
Said centre body A3 comprises two projections A4, preferably arranged in a diametrically opposite position, each equipped with a pin for the insertion of hooks BC1, BC2 that are integral with the corresponding half shells B1, B2. Said half shells B1, B2, which are preferably conical in shape, are suited to create the chamber that contains the plug S of the electric tool or household appliance. The edges B11, B12, B21, B22 of said shells B1, B2 are complementary to each other, meaning that they are of the male/female coupling type, with a centre wall positioned between two corresponding side walls.
Even the semi-circular edges B13, B23 of the two half shells B1, B2 are inserted in the sides present on the edge A6 of the centre body A3.
Each of said half shells B1, B2 comprises, on the side opposite the edge intended to be joined to the centre body A3, an externally threaded semi-circular wall BF1, BF2, in such a way that it can be coupled with the other half shell and form a threaded cylinder. In proximity to said threaded cylinder, formed by said two threaded half cylinders BF1, BF2 coupled together, inner coupling devices BU1, BU2 are provided to lock the power cable of the plug S.
In this case, according to the invention, said coupling devices BU1, BU2 with hook-shaped terminal part are arranged on the head of the parts BF1, BF2.
The device comprises also a tightening element C, made up of two semi-circular parts C1, C2, each provided with a toothed projection C13, C23 suited to be inserted in apposite seats C14, C24 in the corresponding adjacent part C2, C1, thus creating an internally threaded ring nut in the shape of a cap or a dome suited to be screwed on the thread BF1, BF2 created by said semi-cylindrical elements and wherein, during the screwing step, as the inner conical wall C15, C25 advances, pressure is exerted towards the inside of said hook-shaped elements BU1, BU2, which rest against the power cable.
According to the description provided above, it is possible to apply the electrical plug S, of the type for civil applications, directly in the holes A5 of the body A3; successively, after inserting the hooks BC1, BC2 of the half shells B1, B2 in the couplings A4 provided on one side and on the opposite side of the body A3, each of said half shells B1, B2 is rotated until coupling the edges B11, B12, B21, B22 together and closing the two half shells B1, B2 completely.
According to the invention, the protective compartment for the plug is closed by coupling two half shells B1, B2 that form the terminal threaded cylinder BF1, BF2 on which the cap or dome-shaped element C is screwed, which in turn is made up of two semi-circular parts C1, C2, hinged or suited to be hinged to each other at one end or in any case connected or suited to be connected to each other in a preferably reversible manner and which, once coupled together, constitute a single tightening element, like a ring nut, which will be screwed on the threaded ends BF1, BF2 of the two half shells, thus closing the adapter around the plug S and locking it.
Said cap or dome-shaped element C comprises two preferably identical semi-circular parts, each provided with an inner thread CF and an outer knurl CZ. Said cap or dome-shaped tightening element can be opened and divided in two, being formed by two semi-circular parts C1, C2 suited to be coupled to each other; in this way it is possible to release the cap or dome-shaped element from the cable of the plug S.
According to the invention, furthermore, there is a rubber element G serving as a seal between the half shells and the cable, wherein said rubber element G is positioned on the inside BFI2 of the end of the two half shells B1, B2 at the level of the terminal thread BF1, BF2.
According to the invention, said two or more parts C1, C2 of the cap or dome-shaped tightening element C are made integral to each other through the use of an external binding element, such as a toothed clamp, an elastic clamp or other equivalent means.
To withdraw the plug, it is sufficient to unscrew the ring nut or the cap or dome-shaped tightening element, causing the two half shells to be opened and thus releasing the power cable, which makes it possible to disconnect the plug and the cable from the body of the adapter.
The advantages offered by this solution can be easily understood: first of all, it is possible to connect and remove the plug to/from the adapter with no need to use tools such as screwdrivers or pliers; secondly, it is sufficient to turn the dome-shaped element manually as if it were a normal cap until it comes off and to disassemble it and then open the two half shells.
The new adapter for electrical sockets can be conveniently used by professional operators who often need to connect their equipment to industrial plugs or domestic sockets, according to the place where they are working, which can vary even in the same day. Another important characteristic lies in that all the elements can be easily produced at limited costs, since they are moulded plastic elements without internal partitions affecting the plug.
These are the schematic outlines that are sufficient for the expert in the art to carry out the invention; therefore, on practical application, variant embodiments may be produced within the scope of the claims.
Therefore, with reference to the above description and the attached drawings, the following claims are expressed.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.