BACKGROUND

FIELD OF THE INVENTION

The present invention relates to a multi-plug adapter with universal female cylindrical receptacle, for use in wall sockets, which accepts the male plugs of various specifications. Additionally, the female cylindrical receptacle contains a safety mechanism. When the male plug is inserted, the safety mechanism operates by allowing the main electrical switch to become operable. The safety mechanism prevents any single instrument to be pushed into the electrical receptacles.

DISCUSSION OF PRIOR ART

The adaptor falls in the electrical industry sector. It is an electrical apparatus that is an accessory in the sub-segment of the electrical industry. The market is the general consumer, with target market being tourist or traveller i.e. the traveller's adapter. There are several kinds of adapter plugs that cater to meet the needs outlined above, a few are discussed below. US 6942508 titled "Electrical adapter" describes an adapter having a base with conducting pins, which extends from one side for insertion into apertures, has electrical terminals on other side and connected to conducting pins electrically. The base also has a bayonet fitting. There are electrical contacts configured on the body to engage with the terminals of the base when the body and base are secured to one another. The body is also provided with a power chord. US 20110111634 titled "Adapter Plug" describes a three pole adapter plug of the standard CEE 7/7 having an additional contact sleeve for a grounded pin. The plug assembly comprises of two sides, one side having a safety plug with two pins, two earth conductors and a hybrid plug according to the standard CEE 7/7 with an additional contact sleeve. The other side of the plug assembly comprises of a socket for at least one plug of British standard, a housing of the plug assembly and a multiple of contact sleeves, for plug in. The contact sleeves are arranged within a safety plug body, which forms the housing for the adapter plug. US 7,614,892 B2 titled "Electrical plug or socket adapter' ^' ' describes an electrical plug or socket adaptor for establishing an electrical connection between a electrical plug and an electrical socket, said adaptor comprising a housing with at least one electrical plug receiving zone to receive an electrical plug of a kind selected from at least one of a Euro pin electrical plug, British pin electrical plug, North America pin electrical plug and Australia pin electrical plug. The adaptor is configurable to itself be capable of being operatively plugged into an electrical socket of a kind selected from at least two of a Euro pin electrical socket, British pin electrical socket, North America pin electrical socket and Australia pin electrical socket. US 3,945,702 titled "Twist-type electrical connector with safety interlock" describes a twist-type electrical connector having an improved interlock. A male plug and a female receptacle are rotated angularly relative to each other in the twist-type electrical connector to result in engagement of the electrical contacts and to prevent any accidental separation of the male plug and the female receptacle. The male plug and the female receptacle are made up of an insulating material such as nylon. The front face of the female receptacle have slots to receive the male blades and carry detents, which engage with a rear edge of the male blades and hold the blade in its seated or rotated position and conducts electricity. US 20060068608 titled "Rotatable outlet adaptor" describes a rotatable outlet adapter electrically connected with the conventional power outlet and facilitates the attachment of electronic devices to the outlet. The outlet comprises of a rotatable outer section and an inner section connected to each other. The outer section has a front face with a number of conductive input ports situated parallel to the axis and the inner section has a number of conductive output prongs connected to input prongs. This ensures a constant transmission of electricity in these outer and inner prongs and ports. Adapters that act intermediate of a plug and a socket are known. Such adapters may come in the form of a multi-plug adapter described above. In all the patents described above, the electrical female receptacle that accepts male plugs from various countries within the adapter is fixed and stationary. Because of this limitation, the number of female electrical receptacles to accept male plugs increases. Additionally, the conducting strip within the said electrical receptacle is fixed and flush to the walls of the receptacle. This is another limitation, as the male plugs that are inserted into the female receptacle must fit precisely in order to maintain the necessary contact with the conducting strips within the female electrical receptacle. Over time and use, the plastic surrounding the female electrical slot gets abraded and contact can no longer be made effectively.

Additionally, in the patents described above, there are various mechanisms that are employed to select and extract male pins from within the adapter. In one example, the adapter houses four male pins, which can be pushed outwards and out of the housing by a lever. This increases the size and complexity of the adapter as it contains independent mechanisms to operate each male pin separately. In another example, the male pins fold into the adapter. Once again, while the lever mechanism is done away with, the size of the adapter remains large as it contains all the male pins that are folded into the body of the adapter.

A significant challenge is to design an adaptor that is compact and contains:

a) The four plugs to connect to the four most common socket configurations being used in foreign countries;

b) The ability to accept all plugs from various countries; and

c) The ability to perform its intended function in a safe manner. The present invention described below seeks to provide a new and improved form of multi-plug adapter with individually replaceable male pins and a rotating female cylindrical receptacle with tensile conducting strips that addresses the issues identified above. Furthermore, conventional power receptacle such as wall receptacles or extension cord receptacles have one or more holes to receive plugs. The electrical conductors in open holes may corrode due to the moisture in the air or their electrical conductivity may be affected by dust accumulation. Moreover, if used improperly, or if children play with the receptacle, conductive foreign objects may be inserted into the hole. This can cause electrical shock and is of great safety concern.

To solve the above problem, tamper resistant receptacles have been developed. However, these tamper resistant receptacles have various shortcomings. In US 4,379,607, the tamper resistant receptacle describes a plastic biasing member used at each end of the device to urge the shutter to the closed position. In US 5,915,981, the tamper resistant receptacle describes a coaxially disposed compression coil spring used at each end of the device to urge the shutter to the closed position. As another example, in the Chinese patent CN 992543843, the biasing member used in the safety mechanism is an F-shaped metal plate, which tends to become fatigued or broken due to repeated use. In US 8,193,445 B2, it describes two identical sliding blocks and two biasing members that when two prongs of male plugs are inserted, slide opens the aperture to the electrical receptacle.

All these patents describe various ways to prevent objects from being inserted at the face of the electrical receptacle. Furthermore, once inserted, the electrical connection is live and harm or injury results. The present invention describes a safety mechanism that is placed inside the electrical receptacle and prevents single objects from being inserted. Furthermore, only when two pins with equal force are inserted into the electrical receptacle simultaneously, the safety mechanism allows the electrical switch to be turned on by the user. SUMMARY OF THE INVENTION

The present invention relates to a multi-plug adapter with an improved female cylindrical receptacle with safety mechanism for use in multi-plug adapters, extension rods and electrical wall sockets.

The first objective of the present invention is to define a universal female cylindrical receptacle contained in a cylinder that can be rotated by the user to bring into alignment and to pair with the inclined prongs of male plugs of choice. The second objective of the present invention is to define another female cylindrical receptacle that need not be rotated as the electrical conductive strips contained within the electrical receptacle are four in number, extend out from the sides of the electrical receptacle towards the centre of the receptacle and are shaped and placed in such a manner as to grip the inclined prongs of male plugs of different specifications that need to be inserted.

The third objective of the present invention is to define tensile electrical conductive strips or rods that extend outward from the sides of the female cylindrical receptacle and towards the centre of the cylindrical electrical receptacle.

The fourth objective of the present invention is to define particularly shaped heads with safety features on the tensile electrical conductive strips or rods that allow male plugs to slide into the aperture of the female electrical receptacle. The shape of the head detailed in the description and drawings are wedge shaped, slope inwards into the cylinder and are placed at particular angles to allow the male pins at different inclinations and thickness to be inserted without needing to pair them. The fifth and primary objective of the present invention is to describe a multi-plug adapter that holds individual retrievable male pins of selected countries enclosed in place by a plastic flap.

The sixth objective of the present invention is the common plastic base.

The seventh objective of the present invention is the provision of a plastic insert on all individual male pins provided with the adapter. The plastic insert or strip is fixed at the base of the male pin and extends from its base along the outside edge of the male pin with the tip of the plastic insert extending to half the length of the male pin. When the male pin is pushed into a female cylindrical receptacle of any country, it slides in between the outside edge of the male pin and the electrical socket into which the male pin is being pushed, to provide the necessary grip to hold the male pin in place. The eighth objective of the present invention is the provision of screws along the face of the adapter so that the individual male pins can simply be screwed on. In another embodiment, the inset screws are replaced by recesses into which the male pin with plastic base are pushed into and click into place with a ball socket mechanism inset into the adapter.

The ninth objective of the present invention is to describe a safety mechanism that operates within the electrical receptacles of sockets. The safety mechanism comprises of a plastic piece placed within the female cylindrical receptacle that is then further connected to another plastic rod that extends through the base of the positive receptacle.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 shows female sockets alignment available worldwide.

Figure 2a shows the entire multi-plug adapter.

Figure 2b shows the rear face of the multi-plug adapter.

Figure 2c shows the rear face of the multi-plug adapter with inset openings.

Figure 3a shows the plug with a plastic base.

Figure 3b shows the male pins and one or more points where it will be placed.

Figure 3c shows the plastic base of the male plug along with a plastic sleeve.

Figure 3d shows the different view of the male plug.

Figure 4a shows a cylindrical female socket with a conducting metal strip.

Figure 4b shows the cylindrical female socket with a conducting metal rod.

Figure 4c shows the detail description of the conducting metal strip.

Figure 4d shows the safety plunger mechanism in a female cylindrical receptacle. Figure 5 shows the functioning of the safety plunger mechanism in the female cylindrical receptacle.

Figure 6 shows the automatic engaging and disengaging of the switch. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 1 shows female sockets alignment (a-h) available worldwide. Various sockets in the world are aligned at different angles. The male pins are also of different shapes and thickness. The distances between pins are also varied (x and y). The detachable male socket will accommodate these differences in the traveller's kit.

Figure 2a shows the entire multi-plug adapter as a single piece 1. The multi-adapter is made of suitable plastic, either a single continuous mould or in parts that are then joined together. It consists of one or more slots 3 on a surface to house one or more male pins. One or more slots 3 are provided with a plastic flap 2. The plastic flap 2 covers the slots 3 to fix male pins 13. The body of the adapter has one or more compartments with the plastic flap 2 that holds individual male pins of selected countries within the compartment. A front face 4 of the multi-plug adapter accepts one or more male plugs 10. The front face 4 of the adapter holds two rotating cylindrical receptacles, 5b and 5c with tensile electrical inserts with knobs presenting out to enable the user to grip and physically rotate the said cylinder to the desired orientation and a fixed cylindrical receptacle 5a with four tensile electrical inserts that are particularly placed. Further, it shows a stationary new design of contracting and expanding of one or more conducting metal strips 6, which are shaped and placed precisely within the cylindrical receptacle 5a. The cylindrical receptacles 5a, 5b and 5c are placed on the front face 4 of the adapter with the fixed cylindrical receptacle 5a placed in an axis Ά' and the two rotating cylindrical receptacles 5b and 5c are placed perpendicular to the cylindrical receptacle 5a in the axis 'Β'. The cylindrical receptacle 5a is fixed and does not rotate and is the earth terminal on the adapter. The cylindrical receptacles 5b and 5c rotate about their axis. A rear face 7 of the adapter houses the male plugs 10. Figure 2b shows the rear face 7 of the multi-plug adapter. It has a provision 8 to house the male plugs 10, which are oblong, rhomboid or any other suitable shape. They are placed in the manner shown in the figure at an angle that meets the requirements of the invention. Figure 2c shows the rear face 7 of the multi-plug adapter with one or more inset openings. The rear face 7 of the adapter shows the inset openings 9, which accepts the male plugs 10 that can be screwed on. The inset openings 9 are positioned above the provision 8 that has been provided to house the male plugs 10. Figure 3a shows the plug with a plastic base. It describes a plastic base 11 of the male plug 10 that correspond with the provision 8 provided in the rear face 7 of the multi-plug adapter to house the male plugs 10. The plastic base 11 is shaped oval for the female cylindrical receptacle 5a and is shaped rhomboid for the female cylindrical receptacles 5b and 5c and allows one or more male pins 13 at different heights and distances. A metal insert with an opening 12 is provided to grip a ball socket joint inset in the adapter. The metal insert with an opening 12 is placed perpendicular to the rear side of the plastic base 11. It also describes the male pins 13 for various countries. The male pin 13 is placed perpendicular to the front side of the plastic base 11. Further, these pins are color coded based on the countries.

Figure 3b shows the male pins and one or more points where it will be placed. The male plug 10 along with the plastic base 11 consists of one or more points 14 placed distantly on the rear face, where the male pins 13 are placed. The male pins 13 rotate around its axis 14a. The male plug also contains the metal insert with an opening 12that is inserted into the front face of adapter 7 and grips the ball socket joint contained within the adapter. Figure 3c shows the plastic base of the male plug along with a plastic sleeve. The male plug 10 consists of the plastic base 11 along with the plastic sleeve 15. The plastic sleeve 15 is placed towards the end of the male pin 13 near the plastic base 11. When the male pins 13 are pushed into the female receptacle, the plastic sleeve 15 engages against the sides of the receptacle such that it is fixed in a proper manner.

Figure 3d shows the different view of the male plug 10. The male plug 10 contains the plastic base 11, the plastic sleeve 15, and the male pin 13.

Figure 4a shows a female cylindrical receptacle with two conducting metal strips. The positive and negative sockets of the adapter contain the female cylindrical receptacles 5b and 5c that rotate about their axis A-B. It consists of one or more studs 16 on the face of the female cylindrical receptacles 5b and 5c on the edge or face of the adapter 4, which a user grips to rotate the female cylindrical receptacles 5b and 5c. Two or more metal conducting strips 18 are centrally located within the cylindrical receptacles 5b and 5c. The metal conducting strips flex outwardly and towards the centre of the female cylindrical receptacles 5b and 5c. The base of the metal conducting strip is flexed to provide the tensile strength and necessary flexibility to expand and contract when male pins are inserted. Each of the metal conducting strips 18 has a plastic strip 17 at the outside end to prevent any accidental shock. The female cylindrical receptacles 5b and 5c is also provided with a metal base 19 at the end. The metal base 19 conducts electricity. Further, there is a ball socket joint 20 present at the end of the female cylindrical receptacles 5b and 5c placed, behind the metal base 19, which allows the female cylindrical receptacles 5b and 5c to rotate 360 degrees while conducting electricity.

Figure 4b shows a fixed cylindrical female socket with a conducting metal rod. The top view of the female cylindrical receptacle 5a consists of four fixed metal rods 21, which are placed accurately with equal spacing between them in the female cylindrical receptacle 5a.

Figure 4c shows the detailed description of the conducting metal rod for the female cylindrical receptacle 5a. Four fixed metal rods 21 are placed accurately in the female cylinder receptacle 5a. The metal rod 21 has a wedge shaped head and is sloping inwardly as shown in the figure. The metal rod 21 is placed inside the female cylindrical receptacle 5a. The top end of the metal conducting rod 23 is attached to the base of the sloping plastic structure 22 covering the top of the wedge shaped metal rod 21. The precise placement allows male pins that are inclined at different angles to be inserted into the female cylindrical receptacle 5a without having to rotate the cylinder. This function is limited to male pins that are flat in shape. It is to be appreciated that the same function can also be performed by half moon shaped balls instead of the wedge shaped metal rod 21.

Figure 4d shows the safety plunger mechanism in the female cylindrical receptacle 5a. A plastic rod 25 is placed underneath a plastic rod 24 at right angles to extend through an opening 26 at the base of a cylinder within the cylindrical receptacle 5a. The two plastic rods 25 each extending from the positive and negative terminals of the female cylindrical receptacle 5a is connected to a horizontal plastic rod 27 at right angles. The horizontal plastic rod 27 is flat, square or round in shape. When the male pin 13 is inserted into the female cylindrical receptacle 5a, the plastic rod 24 is pushed downwards. This in turn translates into a movement and the plastic rod 24 pushes the plastic rod 25 through an opening 26. The opening 26 allows the easy downward movement of the plastic rods 24 and 25 of the safety plunger mechanism.

Figure 5 shows the functioning of the safety plunger mechanism in the female cylindrical receptacle 5a. The female cylindrical receptacle 5a is shown as two cylinders depicting the positive and negative terminals of the adapter. The base of the cylinder houses the horizontal plastic rod 24, which is shaped according to the country of use. The plastic rod 25 is placed underneath the plastic rod 24 at right angles to extend through the opening 26 at the base of the cylinder. The plastic rod 25 is connected at the right angles downwards to the plastic rod 27, which is flat, square or round in shape. The exact center of the plastic rod 27 is connected to top of a fulcrum 29 at a moveable joint 28. The base of the fulcrum 29 rests in a housing 30, which contains a spring 31 of suitable tension. When the male pins 13 of the male plug 10 are jointly pushed into the positive and negative terminals of the female cylindrical receptacle 5a, the male pins 13 jointly push the plastic rod 24 further pushing the plastic rod 25, which is housed inside the female cylindrical receptacle 5a. The joint force applied by the male pins 13 negates the fulcrum 29. As a result, the moveable joint 28 is forced downwards and the plastic rod 27 also moves down. This downward movement pushes the fulcrum 29 into the housing 30 that contains the spring 31 of suitable tension resulting in electrical conductivity. If only one of the male pins 13 is pushed, then downward force is not translated equally and jointly from the plastic rods 25 onto the fulcrum 29 resulting in the redirection of the force upwards back to the plastic rod 25 and hence there will be failure in electrical conductivity.

Figure 6 shows the automatic engaging and disengaging of the main switch on the wall socket. This mechanism is detailed for use only on electrical wall sockets that contain a main switch that operates the power to the receptacles of the said wall socket. The fulcrum 29 is connected to a fixed spring loaded joint 33 at one end through a linkage 32. The other end is connected to a plastic rod 35 through a linkage 34. The plastic rod 35 is connected to a flat plastic structure 36 resting on a switch 37. The electrical switch 37 is operated by the user to switch the electrical wall socket on or off. The ON position 38 allows the electricity to pass through to the male pins 13 that are inserted into the electrical wall socket. The OFF position 39 of the switch 37 is reached when the flat plastic structure 36 rests and covers ON position 38. When the male pins 13 are jointly pushed into the positive and negative terminals of the wall socket receptacle, the male pins 13 jointly push the plastic rod 24, which negates the fulcrum 29. The moveable joint 28 moves downwards as the plastic rod 27 is pushed downwards by the plastic rod 25. This force is translated towards the linkage 32, which in turn is translated to the spring loaded joint 33. This creates a downward force that is translated into a sideways force that pulls the plastic rod 35 away from the switch 37. As a result, the flat plastic structure 36 connected to the plastic rod 35, resting on a terminal is pulled away from a switch 37 allowing the user to flip the switch 37 to ON position 38. The electricity now passes through the switch 37 of the wall socket. When the male pins 13 are pulled out from the positive and negative terminals of the wall socket, the pressure from the plastic rod 23 is released allowing the spring loaded joint 33 to return to the original position. The plastic rod 35 is pushed into the switch 37 resulting in sliding of the flat plastic structure 36 through the linkage 34 on the switch 37 flipping the switch 37 from its ON position 38 to its OFF position 39.