WO2015076730A1

WO2015076730A1 - Electric plug

Info

Publication number: WO2015076730A1
Application number: PCT/SE2014/051359
Authority: WO
Inventors: Anders GÖRANSSON
Original assignee: Eazyplug Ab
Priority date: 2013-11-20
Filing date: 2014-11-17
Publication date: 2015-05-28
Also published as: SE537610C2; SE1351374A1

Abstract

An electric plug comprising a pin base body (2) with at least two pins (4, 5) for introduction into female members and a hat-like cap (8) arranged on the opposite side of the pin base body with respect to the pins and movable with respect to this body in a connecting direction. A transmission arrangement (14-18) is configured to act between the cap and an element (7) and transfer a movement of the cap (8) with respect to the pin base body (2) in said connecting direction to a movement of the element in the same direction with respect to the pin base body. The cap (8) is movable with respect to the pin base body so as to bring the element (7) to a disconnecting position.

Description

ELECTRIC PLUG TECHNICAL FIELD OF THE INVENTION AND BACKGROUND ART

The present invention relates to an electric plug comprising

• a pin base body with at least two pins projecting therefrom perpendicularly with respect to an end surface thereof in parallel with each other in a connecting direction and configured to be inserted into corresponding female members, and

• an element movable with respect to the pin base body in said connecting direction so as to in a connecting state of the plug in a disconnecting position hit and press against surfaces surrounding said female members so as to enable pushing of the pins out of said female members by generating reaction forces.

Besides all type of plugs for introduction in electric wall sockets the invention also relates to such for connecting to other electric sockets, such as extension cables, cable reels and the like. A not neglectable pulling force has to be applied on the plug by a person so as to release a plug connection made by a said plug. It is experienced as difficult, especially for children, older persons and persons having a reduced strength for another reason, such as being disabled, or difficulty to grip objects to deliver this force. There is for that reason an imminent risk that the person in question chooses to instead pull the electric cord or cable connected to the plug, which finally may result in an exposure and loosening of electric conductors in that cord from the plug, which besides making it useless may cause electrical accidents. Also persons with normal strength have a tendency to find it more comfortable to pull the electric cord for loosening a plug connection. The problem is particularly imminent for plugs forming parts of electrical connections often established and broken, such as plugs for elec- trie equipment, such as vacuum cleaners, hair driers and drilling machines. Electric plugs of the type mentioned in the introduction have been developed for solving the above problem. By providing such a plug with such an element which in the connecting direction is pressed against surfaces surrounding the female members of a connecting member to which the electric plug is to be connected for pressing the pins out of these female members the connecting of which the plug is a part may be broken comparatively comfortable without any need of applying any pulling forces on the plug, and the person handling the plug has neither to be able to even grip the plug. Such electric plugs are known through inter alia EP 1 071 169 A1 and US 4 045 106. However, these plugs already known have a construction complicated in some respect and/or have received comparatively important dimensions with respect to a conventional plug for enabling the "pushing out function" according to the invention.

SUMMARY OF THE INVENTION

The object of the present invention is to provide an electric plug of the type defined in the introduction, which is improved in at least some aspect with respect to such plugs already known.

This object is according to the invention obtained by providing a plug with the features of appended patent claim 1 . By arranging a hat-like cap upon which a pushing force may be applied for moving this with respect to the pin base body and by that move the element in the same direction with respect to the pin base body a disconnection may be achieved by simple means and a minor additional need of space with respect to a conven- tional plug. According to an embodiment of the invention said element is configured to be movable with respect to the pin base body past said end surface so as to in said disconnecting position press against surfaces in which said female members emerge and into which said pins are configured to be inserted in said connecting state of the plug. Such a plug may fulfil its function with respect to the disconnecting possibility by applying a pushing force on the cap irrespectively of the appearance of the connecting member, such as wall socket, to which it is connected, which is not the case for some such electric plugs already known, in which said element does not extend past said end surfaces but is intended to act upon surfaces surrounding said female members on another level than the bottom in a socket into which the plug has been introduced. This means that the plug according to the invention may be made compact.

According to another embodiment of the invention the plug comprises a sleeve configured to receive the pin base body and itself received in and surrounded by said cap and displaceable at least partially into and out of the cap upon movement of the cap with respect to the pin base body in said connecting direction and opposite thereto, respectively. The combination of pin base body, a sleeve housing this and a cup housing the sleeve results in a simple design and a reliable function of the plug according to the invention.

According to another embodiment of the invention the sleeve is configured to have its pin close end as seen in said connecting direction in said connecting state of the plug located in the region of the pin base body where the pins project out of this.

According to another embodiment of the invention the sleeve is designed to form the outer limitation of the plug through external walls, which limitation is configured to interact with walls of a socket with the surfaces directly adjacent to the female members sunk into a bottom hole cavity delimited by said socket walls. The sleeve and the pin base body will by such a design of the sleeve together function as a conventional plug introduced into a said socket, and there is no possibility to by mistake use only the pin base body alone as plug in the case that the plug according to the invention would be disconnected.

According to another embodiment of the invention the plug is configured to form said element. The disconnecting by pressing apart function according to the invention is by this obtained in a simple way and the sleeve gets a double function by housing the pin base body and also accomplishing pressing of the pins out of the female members when applying a pushing force on the cap in the connecting direction. This design is particularly advantageous for a plug according to the embodiment just discussed, in which the sleeve will then keep the plug in the socket and by end edges be pressed against the bottom of said bottom hole cavity.

According to another embodiment of the invention the cap has, as seen in said connecting direction, an inner cross-section de- fined by an internal wall thereof which completely covers the outer cross-sections of the sleeve as well as the pin base body as seen in this direction. No part of the plug will by this project in the transversal direction with respect to the connecting direction more than the cap, so that the plug gets compact and risks for unintentionally damage parts thereof when handling it are minimized.

According to another embodiment of the invention the transmission arrangement is configured to transfer a movement of the cap with respect to the sleeve in the connecting direction to a movement of the pin base body with respect to the sleeve in the opposite direction.

According to a further development of the embodiment last men- tioned a transmission arrangement comprises means of the cap designed to, upon a said movement of the cap with respect to the sleeve in the connecting direction , push a first transmission part received in the sleeve in front thereof in this direction , which transmission part is configured to interact with a second transmission part arranged on the pin base body so as to move the pin base body inwards in the sleeve. Such a design of the transmission arrangement is simple and may be given a reliable function .

According to another embodiment of the invention the transmission arrangement comprises at least one gear rack and a gear interacting therewith , in which in a further development of this a gear rack is fixedly connected to the pin base body and the gear is rotatably journalled in the sleeve. I n a further development of this the transmission arrangement comprises a gear rack which may be acted upon by said cap and is configured to interact with said gear for transferring a movement of the cap with respect to the sleeve into a movement of the pin base body with respect to the sleeve and by that with respect to the cap.

According to another embodiment of the invention the transmis- sion arrangement comprises at least one elongated flexible member, such as a line, and means, such as wheels, configured to divert the elongated member. This constitutes an alternative possibility to realize the transmission arrangement in a plug according to the invention .

According to another embodiment of the invention the plug comprises a spring member configured to act upon the cap with respect to the pin base body in a direction opposite to said connecting direction and be under pretension in a rest position , and the spring member is configured to interact with the cap so that for a said movement of the cap in the connecting direction with respect to the pin base body an application of a force upon the cap in said connecting direction exceeding the spring force of the spring member is required . It is by this ensured that the plug is not un- intentionally transferred to an entirely or partially disconnected state and by that is safely held in the connecting state when this is desired and always returns to a mutual position of the cap and the pin base body corresponding to said rest position as soon as no outer compressive power is applied on the cap. According to a further development of the embodiment last mentioned the spring member is configured to act between the cap and the pin base body. The spring member is then advantageously a compression spring configured to be compressed while storing potential energy upon movement of the cap with respect to the pin base body in the connecting direction.

According to another embodiment of the invention the plug comprises a means configured to, in a locking position, lock the cap with respect to the pin base body against movement in said con- necting direction so as to allow introduction of said pins in said female members by applying a compressive force on the cap in the connecting direction, and said locking means is transferable to a releasing position so as to allow movement of the cap in the connecting direction with respect to the pin base body. By the arrangement of such a locking means connecting and disconnecting of the pins of the plug with respect to said female members may easily and safely be obtained.

According to another embodiment of the invention said element has a rod-like character, and in such a case the transmission arrangement may be configured to transfer a movement of the cap with respect to the sleeve in the connecting direction to a movement of the rod-like element with respect to the sleeve and the pin base body in the same direction.

Further advantages and as well as advantageous features of the invention appear from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, below follows a specific description of an embodiment of the invention cited as an example. In the drawings:

Fig 1 is a perspective view of an electric plug according to an embodiment of the invention, Fig 2 is a sectioned view of the plug according to Fig 1 in a connecting state, i.e. inserted with the pins thereof in electric contact in an electric socket,

Fig 3 is a view corresponding to Fig 2 illustrating how the plug is disconnected from a said socket, and

Fig 4 is a partially sectioned perspective view illustrating the construction of parts of the plug according to Fig 1 . DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

An electric plug 1 according to an embodiment of the invention is illustrated in Fig 1 , and the construction and function thereof will now be explained while simultaneously referring to all the figures 1 -4. The electric plug has a pin base body 2 with two pins 4, 5 projecting in parallel in a connecting direction of the plug from an end surface 3 of the pin base body and perpendicularly with respect thereto, and these pins are designed to be inserted into corresponding female members, which may be located in an electric wall socket, in a sleeve in one end of an extension cord or the like so as to through a conductor 6 connected to the plug connect equipment connected to this to electricity. The pin base body is received in a sleeve 7, which itself is received in a cap 8 arranged on the opposite side of the pin base body with respect to the pins with respect to this body. The sleeve 7 is shown alone in Fig 4. The sleeve 7 is configured to be dis- placeable partially into and out of the cap upon movement of the cap 8 with respect to the pin base body in and opposite, respec- tively, to the direction for connecting the plug to an object having female members, i.e. in the direction shown by the arrow 9 in Fig 2. The sleeve is configured, in said connecting state of the plug, which is shown in Fig 2, to have its pin close end 10 as seen in the connecting direction located in the region of the pin base body where the pins 4, 5 projects out of this. The sleeve 7 is designed to form the outer limitation of the plug by external walls 1 1 configured to interact with walls of a socket upon insertion of the plug in a socket with the surfaces 12 directly connecting to the female members sunken or lowered into a bottom hole cavity 13 delimited by the socket walls.

The plug has also a transmission arrangement configured to transfer a movement of the cap 8 with respect to the sleeve 7 in the connecting direction 9 into a movement of the pin base body 2 with respect to the sleeve in the opposite direction. The transmission arrangement has for achieving this a gear rack 14 arranged at the end of the pin base body opposite to the pins and gears 15 rotatably arranged inside the sleeve 7 and in engagement on a side each of the gear rack 14. The transmission ar- rangement has also a transmission part 16 formed by two gear racks 17, 18 mutually fixedly interconnected through a transversal piece 19. The transmission part 16 is shown disconnected from other parts of the plug in Fig 4. One end 20 of the transmission part 16 is designed to bear against an internal surface 21 on the end of the cap 8 located opposite to the pins so as to be pushed on by the cap when the cap is displaced in the connecting direction 9 with respect to the sleeve. The gear racks 17, 18 of the transmission part 16 are in engagement with the gears 15 on the opposite side, i.e. externally, with respect to the gear rack 14 of the pin base body. A spring member in the form of a compression spring 22 is configured to act between said internal surface 21 of the cap 8 and a counter surface 23 of the pin base body in a direction opposite to the connecting direction 9 and be under pretension in a rest po- sition (the position according to Fig 2) of the plug. The spring member is designed to interact with the cap so that for a movement of the cap in the connecting direction 9 with respect to the pin base body it is necessary to apply a force on the cap in the connecting direction exceeding the spring force of the spring member.

The plug comprises also a means 24 of which only a lug interacting with a recess in shown, which is designed to lock the cap with respect to the pin base body in a locking position by locking the sleeve with respect to the cap, with respect to movement in the connecting direction 9 so as to allow introduction of the pins 4, 5 in female members of a socket by applying a pushing force on the cap in the connecting direction. The means 24 also comprises stop pins not shown which when turning the cap 8 with respect to the sleeve lock the cap 8 against movement with respect to the pin base body 2. This locking means is transferable to a releasing position so as to allow movement of the cap in the connecting direction with respect to the sleeve and by that the pin base body as shown for a transfer of the plug from the position according to Fig 2 to that according to Fig 3.

The function of the plug according to the invention is as follows. When the plug is to be inserted in a socket the locking means 24 is brought in a locking position, so that the rest position the plug has in Fig 1 will be maintained even if forces for displacing the cap 8 with respect to the sleeve are applied in the direction of the arrow 9. The parts forming the plug are by that immovable with respect to each other, and the plug may be connected to a socket by pushing the pins 4, 5 into the female members of the socket by pushing onto the end surface 25 of the cap 8. The position according to Fig 2 is by that obtained. Would it now be desired to disconnect the plug from the socket the cap 8 is turned with respect to the sleeve 7 by gripping a flange 26 intended for this, so that the locking means 24 is trans- ferred to an unlocked position. The spring member 22 will still keep the plug in the position shown in Fig 2. If a pushing force is now applied on the end surface 25 of the cap, as is shown through the arrow 27 in Fig 3, and this pushing force is so great that it manages to exceed the spring force of the spring member 22, the cap will be displaced in the direction according to the arrow 9 with respect to the sleeve 7 while pushing the transmission part 16 in front of it. The gear racks 17, 18 of the transmission part 16 will bring the gears 15 of the sleeve to rotate, and these will feed the gear rack 14 of the pin base body in the direction opposite to the arrow 9, so that the pin base body will be pushed inwards in the sleeve and the sleeve by that function as a disconnecting element by pressing against surfaces surrounding the female members for pushing the pins 4, 5 out of the female members by generating reaction forces, as shown in Fig 3.

The invention is of course not in any way restricted to the embodiment described above, but many possibilities to modifications thereof would be apparent to a person skilled in the art without diverting from the scope of the invention as defined in the ap- pended claims.

It would for example be possible to design the transmission arrangement differently and provide this with an elongated flexible member, such as a line, and means, such as wheels designed to divert the elongated member so as to achieve the movement pattern described above between the cap, the sleeve and the pin base body for disconnecting the plug from a socket.

Claims

An electric plug comprising

• a pin base body (2) with at least two pins (4, 5) projecting therefrom perpendicularly with respect to an end surface (3) thereof in parallel with each other in a connecting direction and configured to be inserted into corresponding female members, and

• an element (7) movable with respect to the pin base body in said connecting direction so as to in a connecting state of the plug in a disconnecting position hit and press against surfaces (12) surrounding said female members so as to enable pushing of the pins out of said female members by generating reaction forces,

characterized in that the plug further comprises a hat like cap (8) arranged on the opposite side of the pin base body (2) with respect to the pins and movable with respect to this body in said connecting direction (9) as well as a transmission arrangement configured to act between the cap and said element (7) and transfer a movement of the cap with respect to the pin base body in said connecting direction to a movement of the element in the same direction with respect to the pin base body (2), and that the cap is movable with respect to the pin base body for moving the element to said disconnecting position.

The plug according to claim 1 , characterized in that said element (7) is configured to be movable with respect to the pin base body (2) past said end surface (3) so as to in said disconnecting position press against surfaces (12) in which said female members emerge and into which said pins (4, 5) are configured to be inserted in said connecting state of the plug.

The plug according to claim 1 , characterized in that it com¬

prises a sleeve (7) configured to receive the pin base body

(2) and itself received in and surrounded by said cap (8) and displaceable at least partially into and out of the cap upon movement of the cap with respect to the pin base body in said connecting direction and opposite thereto, respectively.

The plug according to claim 2 or 3, characterized in that the sleeve (7) is designed to have its pin close end (10) as seen in said connecting direction (9) in said connecting state of the plug located in the region of the pin base body (2) where the pins project out of this.

The plug according to claim 3 or 4, characterized in that the sleeve (7) is designed to form the outer limitation of the plug through external walls (1 1 ), which limitation is configured to interact with walls of a socket with the surfaces (12) directly adjacent to the female members sunk into a bottom hole cavity (1 3) delimited by said socket walls.

The plug according to any of claims 3-5, characterized in that the sleeve (7) is configured to form said element.

The plug according to any of claims 3-6, characterized in that the cap (8) has, as seen in said connecting direction, an inner cross-section defined by an internal wall thereof which completely covers the outer cross-sections of the sleeve (7) as well as the pin base body (2) as seen in this direction.

The plug according to any of claims 3-7, characterized in that the transmission arrangement is configured to transfer a movement of the cap (8) with respect to the sleeve in the connecting direction (9) to a movement of the pin base body (2) with respect to the sleeve (7) in the opposite direction.

The plug according to claim 8, characterized in that the transmission arrangement comprises means (21 ) of the cap (8) designed to, upon a said movement of the cap with respect to the sleeve (7) in the connecting direction (9), push a first transmission part (16) received in the sleeve in front thereof in this direction, which transmission part is configured to interact with a second transmission part (14) arranged on the pin base body (2) so as to move the pin base body (2) inwards in the sleeve (7).

The plug according to any of the preceding claims, characterized in that said transmission arrangement comprises at least one gear rack (14, 17, 18) and a gear (15) interacting therewith.

The plug according to claims 3 and 10, characterized in that a said gear rack (14) is fixedly connected to the pin base body (2) and the gear (15) is rotatably journalled in said sleeve (7).

The plug according to claim 1 1 , characterized in that said transmission arrangement comprises a gear rack (17, 18) which may be acted upon by said cap (8) and is configured to interact with said gear (15) for transferring a movement of the cap with respect to the sleeve (7) into a movement of the pin base body (2) with respect to the sleeve and by that with respect to the cap.

The plug according to any of claims 1 -9, characterized in that the transmission arrangement comprises at least one elongated flexible member, such as a line, and means, such as wheels, configured to divert the elongated member. 14. The plug according to any of the preceding claims, characterized in that it comprises a spring member (22) configured to act upon the cap (8) with respect to the pin base body (2) in a direction opposite to said connecting direction (9) and be under pretension in a rest position, and that the spring member (22) is configured to interact with the cap (8) so that for a said movement of the cap in the connecting direction with respect to the pin base body (2) an application of a force upon the cap in said connecting direction (9) exceeding the spring force of the spring member is required.

The plug according to claim 14, characterized in that said spring member (22) is configured to act between the cap (8) and the pin base body (2).

The plug according to claim 14 or 1 5, characterized in that said spring member (22) is a compression spring configured to be compressed while storing potential energy upon movement of the cap (8) with respect to the pin base body (2) in said connecting direction (9). 17. The plug according to any of the preceding claims, characterized in that it comprises a means (24) configured to, in a locking position, lock the cap (8) with respect to the pin base body (2) against movement in said connecting direction (9) so as to allow introduction of said pins (4, 5) in said female members by applying a compressive force on the cap in the connecting direction, and that said locking means (24) is transferable to a releasing position so as to allow movement of the cap (8) in the connecting direction (9) with respect to the pin base body (2).

The plug according to any of claims 1 -5 or 7-1 5 independent of claim 6, characterized in that said element has a rod-like character.

The plug according to claim 18, characterized in that the transmission arrangement is configured to transfer a movement of the cap with respect to the sleeve in the connecting direction to a movement of the rod-like element with respect to the sleeve and the pin base body in the same direction.