ELECTRIC SOCKET WITH IMPROVED DISCONNECTION CHARACTERISTICS

Abstract: The electric socket of the invention comprises a receiving part (12) with a depression (23) for receiving a plug, a body (3) for supporting the receiving part (12), wherein in the receiving part (12) and the body (3) holes (5) are made which are equipped with contacts (15) for securing current way between an electric network and pins of the plug inserted into the depression (23) and to the receiving part (12) means for facilitating removal of the plug from the receiving part (12) are assigned. The facilitating means include a pushing rod (1) supported on and guided in the receiving part (12) or in the body (3) connected to a pushing plate (2) made as a two-armed lever having an outer and an inner end (16, 19), the pushing plate (2) being supported so that under action of the pushing rod (1) in a first direction the inner end (19) of the pushing plate (2) moves oppositely and parallel to the first direction, wherein the outer end (16) is in an operating connection with the pushing rod (1), and the inner end (19) is arranged substantially in the middle region of the depression (23).

Description: ELECTRIC SOCKET WITH IMPROVED DISCONNECTION CHARACTERISTICS FIELD OF INVENTION The present invention refers to an electric socket for realizing electric connection of a consumer with an electric network by the means of a plug, wherein the electric socket comprises means for facilitating the removal of the plug, i.e. the step of disconnecting the socket and the plug. The proposed socket shows improved application features when the plug should be removed therefrom. BACKGROUND OF THE INVENTION The electric sockets of known designs comprise connecting cheeks which are pressed to the pins of the plug inserted into a depression prepared in the socket. The pressure exerted by the cheeks ensures that the plug can be removed from the electric socket by applying a force in a range defined by a minimal and a maximal nominal value. This value is increased by the friction between the plug and the walls of the depression of the socket which is rather difficult to determine. Most of the constructions have the disadvantage that the force exerted by one hand of a user may be not sufficient for overcoming the opposition of the plug because with the other hand the socket should be kept in position. Hence, the socket is exposed to high pulling force and this can be compensated by applying ears or tongues fixing the electric socket against the surface of a box built-in into a wall. In spite of applying different means for securing the socket in its position during removal of the plug it occurs sometimes that the socket is drawn out from the wall, together or without the box is disconnected with the electric conductors which become free and this can be dangerous for the human life. It is also dangerous if the plug is pulled out by its cable part because the high pulling force may cause disruption of the cable at the place of mounting it in the plug. Another disadvantage can be that when under high force the socket is broken away from the box in the wall the ends of the _ ? . regularly rigid conductors come away and the socket can be built back only with difficulties because of necessity of making a section of the conductors free. Sometimes in such cases the conductors can contact one another and this is a situation when fire can explode. The shortened conductors can cause many practical problems during installation works. The mentioned disadvantages are especially dangerous when the socket is built in in a place which is difficult of attainment and the plug, however relatively easily insertable (pushable) into the socket is hard to remove because the socket can not practically be supported by hand during the removal of the plug. There have become some means known for facilitating the removal of the plug from the socket. The US-PS No. 4,114,969 shows a socket comprising a spring wherein by inserting the plug the spring is compressed and the elastic power deliberated during removal facilitates this step. A similar construction is described in the EP-PS No. 0,203,808. This solution ensures relative ly low elastic force which can be sufficient for the American type sockets and plugs but many times is not sufficient when applying European type elements, especially when the electric socket is prepared for grounded installations. The US-PS 4,042,292 discloses another proposal for facilitating the removal of plugs of small and middle size household apparatuses from electric sockets. The socket is completed according to this patent by a tilting plate arranged in the form of an angle lever whereon the plug inserted is supported. The problem is that the tilting plate is rather thick. The thicker the tilting plate, the easier to remove the plug but the shorter the effective length of the pins of the plug. Of course, thickness of the lever can be reduced by applying high strength materials which are regularly either expensive plastics, composites or metals. The first possibility is not acceptable because of the costs, and the second one with regard to safety problems. SUMMARY OF THE INVENTION The object of the present invention is to realize a construction for electric sockets which is free of the disadvantages mentioned above, i.e. offers the possibility of easy, "one-hand" removal of the plug without the danger of drawing out the electric socket from the box and thereby excludes the possibility of making the electric conductors attainable either those connected to the socket or those mounted into the interior of the plug. The invention is based on the recognition that for facilitating the removal of the plug from an electric socket a force should be applied which has direction opposite to the direction of the movement of the plug during removal. This means, the invention foresees that the plug should be removable by application of a pushing force instead of pulling it out. It is a well known experience that a human being can carry out the action of pushing easier than a pulling step. Hence, according to the recognition a pushing force originated from the socket should act on the plug. In this way it is practically impossible to pull out the socket from the wall when removing the plug, more exactly from the box forming a receptacle of the socket, the plug is subjected to pushing force and thereby the danger of pulling out the conductors of the plug extincts. Thus, the essence of the invention is that the step of pulling out the plug should be facilitated by a construction reverting the direction of action of the force and this construction should form a part of the electric socket. Hence, the object of the present invention is an electric socket showing improved disconnection characteristics which comprises a receiving part with a depression for receiving a plug, a body for supporting the receiving part, wherein in the receiving part and the body holes are made which are equipped with contacts for securing current way between an electric network and pins of the plug inserted into the depression and to the receiving part means for facilitating removal of the plug from the receiving part are assigned. The essence of the proposed solution is that the facilitating means include a pushing rod supported on and guided in the receiving part or in the body, connected to a pushing plate made as a two- armed lever having an outer and an inner end, further, the pushing plate is supported so that under action of the pushing rod in a first direction the inner end of the pushing plate moves oppositely and parallel to the first direction, advantageously it forms a rocking lever supported between the depression and the body, wherein the outer end is in an operating connection with the pushing rod, and the inner end is arranged substantially in or below the middle region of the depression. According to a first aspect of the invention in the proposed electric socket the pushing rod is supported on and guided in the receiving part, the pushing plate lies within the depression and its inner end is made with an involute shaped pushing surface. According to a second aspect of the invention in the novel electric socket the pushing rod is supported on the body and guided in the receiving part, the inner end of the pushing plate is in operating connection with a pushing element, wherein the pushing element is arranged in the middle part of the depression. According to a third aspect of the invention in the electric socket the receiving part or a section thereof forms a nest arranged between guiding means wherein the pushing rod is supported on the body and connected with the pushing plate lying under the receiving part. If the nest is made as a section of the receiving part, the pushing rod is preferably supported either on the receiving part or on the body independently from the nest and the pushing plate is arranged under the nest. Preferably, in the electric socket of the invention the pushing rod and the pushing plate are made of appropriate high strength plastics. The life time of the electric socket of the invention can be increased if between the pushmg rod and the pushing plate is a fork type connection wherein preferably the outer end of the pushing plate is made with two outer parts of changing thickness arranged adjacent to a narrower part of the pushing rod. Because of ensuring good conditions of power transmission it is advantageous when the pushing rod and the pushing plate are arranged at right angle. Under this aspect it is also preferred when the section of the outer end of the pushing plate connecting the pushing rod is made with thickness having a minimal value at the point of connection with the pushing rod. The electric socket of the invention can be applied in households and gen- erally in every case when the socket is installed in place which is difficult to reach. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further described in more detail with reference to the accompanying drawings showing by way of example only some preferred embodiments of the electric socket proposed by the invention. In the drawings Fig. 1. is the cross-section of a first proposed embodiment of the electric socket of the invention in a broken plane I-I shown in Fig. 2., Fig. 2. is the top view of the embodiment of the electric socket illustrated in cross- -section in Fig. 1., Fig.3. is the cross-section of a second proposed embodimen of the electric socket of the invention in a broken plane II-II shown in Fig.4., Fig. 4. is the top view of the embodiment of the electric socket illustrated in cross- -section in Fig.3., Fig. 5. is the cross-section of a third proposed embodiment of the electric socket of the invention in a broken plane III-III shown in Fig. 6., and Fig. 6. is the top view of the embodiment of the electric socket illustrated in cross- -section in Fig. 5. DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS The electric socket proposed by the invention will be described with reference to the electric sockets of design looking generally like those being in common use in Europe and many other parts of the world (Figs 2., 4., 6.). In these constructions the electric socket is divided into a receiving part 12 determining a depression 23 for the plug (not shown) and a body 3 wherein holes 5 of circular cross-section corresponding to the pins of the plug are present. The body 3 and the receiving part 12 are united to each other via at least one clamping plate arranged in the body and by respective screws supported in the receiving part 12. In the body 3 in the holes 5 contacts 15 made of resilient material are arranged which are pressed with predetermined force to the pins of the plug inserted into the electric socket. Within the depression 23, on its side wall lateral contacts 22 are prepared for securing third electric current way required in the grounded electric appliances, the lateral contacts being in electric coupling with plate 4 secured by a screw or other known way in the body 3. Of course, the general principles of the present invention can be applied to sockets of other designs also, without departing from the essence of the invention expressed in the attached claims. -As illustrated in Figs 1., 3., 5. the construction of the proposed electric socket is similar to that of the electric sockets commonly used in Europe in households for contacting low or middle power consumers to the electric network. As mentioned above, this socket comprises a receiving part 12 and a body 3 wherein holes 5 with contacts 15 are arranged. The receiving part 12 and the body 3 of the socket is completed with well known fixing means, i.e. a tongue 7 to be pressed by a screw 6 to a box (not illustrated) built-in into a wall of a building and a bended plate type supporting element 8 connected to a base frame member 9 holding the upper part of the socket, the upper part forming a covering plate 10 defining a depression 23 for receiving the plug (not illustrated). This arrangement is common in all embodiments of the electric socket proposed by the invention and does not form any novel feature. The novelty of the electric socket constructed according to the present invention lies in applying a pushing rod 1 which is inserted at an appropriate place of the covering plate 10 into the receiving part 12 and is supported and guided by the last (Figs 1., 3., 5.) or the body 3. The pushing rod 1 is connected with an outer end 16 of a pushing plate 2 supported on the body 3 or on a receiving member 18 belonging to the receiving part 12. The pushing plate 2 constitutes a two-armed 5 lever, i.e. an element which can be rotated on a supporting surface 14 around an appropriate axis of rotation. Preferably, the pushing plate 2 constitutes a rocking lever supported within the receiving part or on the body 3 and connected at right angle with the pushing rod 1. Of course, the pushing plate 2 can be supported also independently on either the body 3 or the receiving part 12. The supporting surface 10 14 lies preferably under the bottom plane of the depression 23. The pushing plate 2, as mentioned, is connected at its outer end 16 with the pushing rod 1, and its other, inner end 19 lies in or near to the middle region of the depression 23 where it comes into direct or indirect contact with the middle section of the plug. The pushing rod 1 is prepared with an extension 24 having either an inner opening (not shown) limited 5 from the bottom by a bolt 17 or two outer depressions determining a narrower middle line section (not shown, too). In the first case the outer end 16 of the pushing plate 2 is inserted into the inner opening of the pushing rod 1, in the second case the outer end 16 of the pushing plate 2 surrounds as a fork the narrower middle line section of the pushing rod 1 in the region of the extension 24. The outer end 16 of 0 the pushing plate 2 can be made with smoothly changing thickness with minimal value in the region where the pushing plate 2 is connected with the pushing rod 1. This change follows from the conditions of power transmission between the pushing plate 2 and the pushing rod 1. The pushing plate 2 fits the receiving member 18 defining the surface of the receiving part 12 contacting the pushing plate 2. 5 The pushing rod 1 and the pushing plate 2 are preferably made of high strength plastics because thereby the safety problems can be avoided. The electric socket of the present invention can be realized in some simple basic embodiments. The first of them is shown in details in Fig. 1. Here it can be seen that the 0 pushing rod 1 lies in an inner opening prepared in the outer end 16 of the pushing plate 2 to form a fork type connection and the pushing plate 2 constitutes a rocking ver. The pushing plate 2 is arranged in diagonal direction in the bottom level of the depression 23, its width is selected so that it does not cover the hole 5. Obviously it is possible to prepare it with greater width but in this case within the pushing plate 2 an opening should be made in order to leave the hole 5 attainable for the pin of the plug. In this construction when applying pushing force to the outer end 16 of the pushing plate 2 by the means of the pushing rod 1 the inner end 19 of the rock¬ ing lever having an involute shaped pushing surface 13 elevates and moves in direc¬ tion opposite to the direction of the pushing force. It is preferred that the pushing surface 13 of the rocking lever lies as near as possible to the geometric middle point of the plug. This can be ensured when the inner end 19 of the rocking lever is consti¬ tuted by the involute shaped pushing surface 13. The rocking lever lies in this embodiment on the supporting surface 14 prepared in the receiving member 18. The cross-section of another preferred embodiment of the electric socket built-up according to the present invention is illustrated in Fig. 3, wherein the plate 4 is not necessary because the electric socket of this type may not be connected to a grounded conductor of an electric network. Hence, the lateral contacts 22 are not present in the depression 23. The difference to the solution reported with reference to Fig. 1. lies in that the pushing plate 2 rests on the supporting surface 14 prepared in the upper part of the body 3 and its inner end 19 is contacted with a pushing element 11. Between the receiving member 18 and the body 3 a nest space 21 is left wherein the pushing plate 2 can rotate. When pressing the pushing rod 1 downwards, the inner end 19 of the pushing plate 2 makes the pushing element 11 move upwards and this facilitates the removal of the plug from the holes 5 and the depression 23. In a further preferred embodiment of the electric socket of the invention illustrated in Fig. 5 a section or the entity of the receiving part 12 constitutes a nest which is arranged between guiding members 20. The nest as a whole entity can be translated by the action of the pushing plate 2. The pushing plate 2 covers in this case also, similarly to the solution of Fig. 3 the upper surface of the body 3 as a supporting surface 14 and forms a rocking lever. When pressing the pushing rod 1 downwards this movement is translated to the receiving part 12 which, together with the plug, is taken apart from the body 3. Thereafter the plug can easily be removed. In the electric socket built-up according to the invention the pushing rod 1 and pushing plate 2 should ensure the translation of the plug on a way which is sufficient for removing the plug from between the contacts 15 in the holes 5. The electric socket of the present invention can be used in all appliances which serve to realizing temporary electric connections with the help of plugs, i.e. not only in households but in the industry and services. By facilitating the removal of the plug the socket proposed by the invention improves the security of electric networks cooperating with different consumers.

Claims: CLAIMS 1. Electric socket with improved disconnection characteristics comprising a receiving part (12) with a depression (23) for receiving a plug, a body (3) for supporting the receiving part (12), wherein in the receiving part (12) and the body (3) holes (5) are made which are equipped with contacts (15) for securing current way between an electric network and pins of the plug inserted into the depression (23) and to the receiving part (12) means for facilitating removal of the plug from the receiving part (12) are assigned, characterized in that the facilitating means include a pushing rod (1) supported on and guided in the receiving part (12) or in the body (3) connected to a pushing plate (2) made as a two-armed lever having an outer and an inner end (16, 19), the pushing plate (2) being supported so that under action of the pushing rod (1) in a first direction the inner end (19) of the pushing plate (2) moves oppositely and parallel to the first direction, wherein the outer end (16) is in an operating connection with the pushing rod (1), and the inner end (19) is arranged substantially in or below the middle region of the depression (23). 2. The electric socket as set forth in claim 1, characterized in that the pushing rod (1) is supported on and guided in the receiving part (12), the pushing plate (2) lies within the depression (23) and its inner end (16) is made with an involute shaped pushing surface (13). 3. The electric socket as set forth in claim 1, characterized in that the pushing rod (1) is supported on the body (3) and guided in the receiving part (12), the inner end (16) of the pushing plate (2) is in operating connection with a pushing element (11), wherein the pushing element (11) is arranged in the middle part of the depression (23). 4. The electric socket as set forth in claim 1, characterized in that the receiving part (12) forms a nest arranged between guiding means (20) wherein the pushing rod (1) is supported on the body (3) and connected with the pushing plate (2) lying under the receiving part (12). 5. The electric socket as set forth in claim 1, characterized in that in the receiving part (12) a nest for receiving the plug is made, which is arranged between guiding means, wherein the pushing rod (1) is supported either on the receiving part (12) or on the body (3) independently from the nest and the pushing plate (2) is arranged under the nest. 6. The electric socket as set forth in any of claims 1 to 5, characterized in that the pushing plate (2) is arranged between the body (3) and the depression (23) and constitutes a rocking lever. 7. The electric socket as set forth in any of claims 1 to 6, characterized in that the pushing rod (1) and the pushing plate (2) are made of plastics. 8. The electric socket as set forth in any of claims 1 to 7, characterized in that between the pushing rod (1) and the pushing plate (2) is a fork type connection. 9. The electric socket as set forth in claim 8, characterized in that in the fork type connection the outer end (16) of the pushing plate (2) is made with two outer parts of changing thickness arranged adjacent to a narrower part of the pushing rod (1). 10. The electric socket as set forth in any of claims 1 to 9, characterized in that the pushing rod (1) and the pushing plate (2) are arranged at right angle.

Inventors: MURLASITS ATTILA, MURLASITS, ATTILA
Applicants: PRODAX KFT, PRODAX KFT.
Application year: 1992
Main classification: H01R13
IPC codes: H01R13