Circuit breaking apparatus Number:6,762,376 from the United States Patent and Trademark Office (PTO) owispatent

Title: Circuit breaking apparatus

Abstract: A load side terminal connected to a load portion, a power source side terminal connected to a power source portion and a sacrifice electric pole connected to the power source side terminal are fixed to an apparatus main body. A movable plug is provided movably to the apparatus main body. The sacrifice electrode is constituted by a sacrifice electric pole with resistor connected to the power source side terminal via a resistor and a through sacrifice electric pole directly connected to the power source side terminal and arranged to shift from each other such that in a procedure of moving a conductive portion of the movable plug from a circuit opened position to a circuit closed position. The conductive portion is firstly brought into contact with the load side terminal, successively brought into contact with the sacrifice electric pole and finally brought into contact with the power source side terminal.

Patent Number: 6,762,376 Issued on 07/13/2004 to Nakamura,   et al.

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Inventors:	Nakamura; Goro (Shizuoka, JP), Satoh; Takahiro (Shizuoka, JP), Yokoyama; Hidenori (Aichi, JP), Kobayashi; Hiroshi (Aichi, JP)
Assignee:	Yazaki Corporation (Tokyo, JP)
Appl. No.:	10/125,552
Filed:	April 19, 2002

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Foreign Application Priority Data

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Apr 20, 2001 [JP]			2001-122797
Apr 20, 2001 [JP]			2001-122816
Apr 20, 2001 [JP]			2001-122820
Apr 20, 2001 [JP]			2001-122833
Apr 20, 2001 [JP]			2001-123373

Current U.S. Class:	200/60 ; 200/51.01; 200/51.09; 439/181
Current International Class:	H01H 9/08 (20060101); H01H 9/00 (20060101); H01H 9/30 (20060101); H01H 9/38 (20060101); H01H 31/00 (20060101); H01H 9/42 (20060101)
Field of Search:	200/17R,11A,181,237,254 218/14

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References Cited [Referenced By]

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U.S. Patent Documents

	3691511		September 1972		Billmann
	4224486		September 1980		Zimmerman, Jr. et al.

Foreign Patent Documents

	515764		Jan., 1931		DE
	736367		Jun., 1943		DE
	44 39 671		May., 1996		DE
	0 742 568		Nov., 1996		EP
	1.574.185		Jul., 1969		FR
	3067588		May., 2000		JP
	WO 01/28062		Apr., 2001		WO

Primary Examiner: Enad; Elvin
Assistant Examiner: Poker; Jennifer A.
Attorney, Agent or Firm: Sughrue Mion, PLLC

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Claims

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What is claimed is:

1. A circuit breaking apparatus comprising: an apparatus body; a load side terminal connected to a load portion and provided in the apparatus body; a power source side terminal connected to a power source portion and provided in the apparatus body; a sacrifice electrode portion connected to the power source side terminal and provided in the apparatus body; and a movable plug including a conductive portion and movable with respect to the apparatus body between a circuit opened position in which the movable plug does not electrically connect the load side terminal to the power source side terminal and a circuit closed position in which the movable plug electrically connects the load side terminal to the power source side terminal, wherein the load side terminal, the power source side terminal and the sacrifice electrode portion are shifted in a direction of moving the movable plug such that when the movable plug is moved from the circuit opened position to the circuit closed position, the conductive portion is brought into contact with the load side terminal, the sacrifice electrode portion and the power source side terminal in order.

2. The circuit breaking apparatus according to claim 1, wherein the sacrifice electrode portion includes a first sacrifice electric pole electrically connected to the power source side terminal through a resistor, and a second sacrifice electric pole electrically directly connected to the power source side terminal, and when the movable plug is moved from the circuit opened position to the circuit closed position, the movable plug is firstly brought into contact with the first sacrifice electric pole and secondly brought into contact with the second sacrifice electric pole.

3. The circuit breaking apparatus according to claim 1, wherein the sacrifice electrode portion is electrically directly connected to the power source side terminal.

4. The circuit breaking apparatus according to claim 1, wherein a first face of the conductive portion firstly brought into contact with the sacrifice electrode portion and a second face of the conductive portion brought into contact with the power source side terminal, differ from each other.

5. The circuit breaking apparatus according to claim 4, wherein the conductive portion includes a side face which extends along the direction of moving the movable plug and corresponds to the first face and a tapered face on a front end thereof corresponding to the second face.

6. The circuit breaking apparatus according to claim 1, wherein the sacrifice electrode portion includes a sacrifice electric pole contactable with the conductive portion and an elastic arm portions connecting the sacrifice electric pole with the power source side terminal.

7. The circuit breaking apparatus according to claim 5, wherein the sacrifice electrode portion includes a sacrifice electric pole contactable with the conductive portion and an elastic arm portions connecting the sacrifice electric pole with the power source side terminal, and the sacrifice electric pole is elastically slidable on the side face of the conductive portion.

8. A circuit breaking apparatus comprising: an apparatus body; first and second terminals provided in the apparatus body, respectively; a movable plug including a conductive portion and movable with respect to the apparatus body between a circuit opened position in which the movable plug does not electrically connect the first terminal to the second terminal and a circuit closed position in which the movable plug electrically connects the first terminal to the second terminal; a guide groove provided at one of the apparatus body and the movable plug; and a projection insertable into the guide groove and provided at the other of the apparatus body and the movable plug, wherein the movable plug is inserted into the apparatus body only when the projection is inserted into the guide groove.

9. The circuit breaking apparatus according to claim 8, wherein the first and second terminals have a tubular cylindrical shape, and the conductive portion is a cylindrical rod insertable into the first and second terminals, respectively, so that the conductive portion is electrically connected with the first and second terminals.

10. The circuit breaking apparatus according to claim 9, wherein the guide groove has a rotation guide portion extending to a depth side in a direction skewed to a direction orthogonal to a direction of inserting the movable plug, and when the conductive portion is in contact with the first and second terminals, the projection is slid along the rotation guide portion.

11. The circuit breaking apparatus according to claim 10, wherein the movable plug includes an operation lever to which the projection or the guide grooves is provided and which rotatably supports the conductive portion.

12. The circuit breaking apparatus according to claim 8, wherein the guide groove includes a projection pickup portion having a large width on a side of an insertion port of the apparatus body firstly inserted with the projection and the width is gradually narrowed toward the insertion depth.

13. The circuit breaking apparatus according to claim 8, wherein the guide groove including: a projection pickup portion including a first end portion having a width three to six times as large as a width of the projection on a side of an insertion port of the apparatus body, and a second end portion having a width slightly wider than the width of the projection, the width of the projection pickup portion being gradually narrowed from the first end portion toward the second end portion; a straight advancement guide portion having a constant width slightly larger than the width of the projection and extending in an insertion direction of inserting the movable plug, one end thereof being communicated with the second end portion; and a rotation guide portion extending to a depth side in a direction skewed to a direction orthogonal to the insertion direction, and communicated with the other end of the straight advancement guide.

14. The circuit breaking apparatus according to claim 8, wherein the guide groove includes a rotation guide portion extending in a skewed depth direction relative to a direction orthogonal to a direction of inserting the movable plug, and a rotation introducing guide portion having a large radius of curvature in compared with that of the rotation guide portion, and when the movable plug is moved from the circuit opened position toward the circuit closed position, the projection is moved from a side of the rotation guide portion toward the rotation introducing guide portion.

15. The circuit breaking apparatus according to claim 14, wherein when the conductive portion is in contact with the first and second terminals, the projection is slid along the rotation guide portion.

16. The circuit breaking apparatus according to claim 8, wherein the guide groove includes a rotation guide portion extending in a skewed depth direction relative to a direction orthogonal to a direction of inserting the movable plug, and a rotation introducing guide portion having a large taper angle relative to the direction orthogonal to the direction of inserting the movable plug, and when the movable plug is moved from the circuit opened position toward the circuit closed position, the projection is moved from a side of the rotation guide portion toward the rotation introducing guide portion.

17. The circuit breaking apparatus according to claim 16, wherein when the conductive portion is in contact with the first and second terminals, the projection is slid along the rotation guide portion.

18. The circuit breaking apparatus according to claim 8, wherein the guide groove has a curved shape whose a radius of curvature varies.

19. A circuit breaking apparatus comprising: an apparatus body; a load side terminal connected to a load portion and provided in the apparatus body; a ground side terminal which is connected to the ground, provided in the apparatus body, and movable between a contact position in which the ground side terminal is in contact with the load side terminal and a separated position in which the ground side terminal is separated from the load side terminal; a power source side terminal connected to a power source portion and provided in the apparatus body; a movable plug including a conductive portion and movable with respect to the apparatus body between a circuit opened position in which the conductive portion is not in contact with the power source side terminal and a circuit closed position in which the conductive portion is in contact with the load side terminal and the power source side terminal; and an urging member for urging the ground side terminal to the contact position, wherein the ground side terminal is in the contact position when the movable plug is in the circuit opened position, and wherein the ground side terminal is moved to the separated position against urge force of the urging member when the movable plug is moved from the circuit opened position to the circuit closed position.

20. The circuit breaking apparatus according to claim 19, wherein the ground side terminal includes a pair of contact portion holders opposed each other with respect to a movement center axis of the movable plug, in the contact position, the pair of contact portion holders are arranged on a movement locus of the movable plug, and in the separated position, the pair of contact portion holders are moved in directions separating from each other by a press force of the movable plug and arranged at a position for slidable contact with the conductive portion of the movable plug.

21. The circuit breaking apparatus according to claim 19, wherein the apparatus body is provided with a sacrifice electrode electrically connected to the power source side terminal, and when the movable plug is moved from the circuit opened position to the circuit closed position, the conductive portion is brought into contact with the load side terminal, the sacrifice electrode and the power source side terminal in order.

22. The circuit breaking apparatus according to claim 19, wherein the urging member is a spring.

23. A circuit breaking apparatus comprising: an apparatus body; a load side terminal connected to a load portion and provided in the apparatus body; a power source side terminal connected to a power source portion and provided in the apparatus body; a sacrifice electrode which is connected to the power source side terminal, provided in the apparatus body and interposed between the load side terminal and the power source side terminal; a movable plug including a conductive portion and movable with respect to the apparatus body between a circuit opened position in which the movable plug does not electrically connect the load side terminal with the power source side terminal and a circuit closed position in which the movable plug electrically connects the load side terminal with the power source side terminal; and insulative caps provided at the load side terminal and the power source side terminal, respectively, wherein when the movable plug is moved from the circuit opened position to the circuit closed position, the conductive portion is brought into contact with the load side terminal, the sacrifice electrode and the power source side terminal in order.

24. The circuit breaking apparatus according to claim 23, wherein the insulative cap is provided at one end of the load side terminal facing the sacrifice electrode.

25. The circuit breaking apparatus according to claim 23, wherein the insulative cap is provided at one end of the power source side terminal facing the sacrifice electrode.

26. The circuit breaking apparatus according to claim 23, wherein each of the load side terminal and the power source side terminal includes a cylinder ring portion and a multiple point contact spring member arranged at an inner peripheral face of the cylinder ring portion, and the multiple point contact spring member is fixed to the cylinder ring portion by the insulative cap.

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Description

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BACKGROUND OF THE INVENTION

The present invention relates to a circuit breaking apparatus for electrically breaking an interval between a power source portion and a load portion.

In the case of, for example, an electric automobile, a capacity of a power source which is a battery, is larger than that of an ordinary gasoline engine vehicle or the like. Therefore, when an electric system or the like thereof is subjected to maintenance, a power source circuit is opened (turned off) by a circuit breaking apparatus to thereby ensure safety of operation. There is a related circuit breaking apparatus of this kind as shown by FIG. 26.

As shown by FIG. 26, a circuit breaking apparatus 200 is provided with a main relay 202 and a sub relay 203 respectively controlled to open and close by a control unit 201 and both of the main relay 202 and the sub relay 203 are provided with power source side terminals 205 and 206 connected to a power source portion 204 and load side terminals 208 and 209 connected to a load portion 207. The load side terminal 209 of the sub relay 203 is connected to the load portion 207 by way of a resistor 210.

According to the above-described constitution, when the main relay 202 and the sub relay 203 are disposed at opened positions and a power source circuit is closed, there is carried out a control of closing firstly the sub relay 203 and closing the main relay 202 after elapse of a predetermined time period by the control unit 201. The power source portion 204 and the load portion 207 are connected via the resistor 210 by firstly closing the sub relay 203 and therefore, a capacitor or the like of the load portion 207 is charged by small current and after charging has been finished, the main relay 202 is closed to thereby connect the power source portion 204 and the load portion 207 directly without interposing a resistor.

That is, in the case in which the load portion 207 is provided with a capacitor or the like, when the sub relay 203 is not provided and only the main relay 202 is provided and the power source portion 204 and the load portion 207 are abruptly connected directly without interposing a resistor, in bringing the power source side terminal 205 and the load side terminal 208 into contact with each other, large current flows to the capacitor or the like via the terminals and therefore, arc discharge is generated between the terminals 205 and 208 and there is brought about a situation of melting the terminals 205 and 208. Hence, the sub relay 203 is provided other than the main relay 202 to thereby prevent the terminals from being melted by arc discharge.

However, according to the related circuit breaking apparatus 200, there are needed two relays of the main relay 202 and the sub relay 203 and there is needed the control unit 201 for controlling the relays and therefore, there poses a problem that the cost is high and the apparatus is complicated and large-sized.

There is provided an another circuit breaking apparatus of this kind disclosed in Japanese Patent Laid-Open No. 306265/1996 shown in FIG. 27.

As shown by FIG. 27, there is provided a switch mechanism containing chamber 302 at inside of an apparatus main body 301 of the circuit breaking apparatus 300 and the switch mechanism containing chamber 302 is provided with a pair of rod terminals 303 and 304. The pair of rod terminals 303 and 304 are arranged on a straight line at positions separated from each other. Further, the switch mechanism containing chamber 302 is arranged with a connection cylinder portion 305 of a conductive member in a cylindrical shape and elastic contact portions 306 are provided at two locations on an inner peripheral side of the connection cylinder portion 305.

Further, an operating lever member 307 is supported by the connection cylinder portion 305 via a support pin 307a and a lower end of the operating lever member 307 is provided at the apparatus main body 301 rotatably via a rotating shaft 308. An upper end of the operating lever member 307 is exposed to outside from the apparatus main body 301 and a grub portion 309 is provided at the upper end of the exposed operating lever member 307. By operating the operating lever member 307, the connection cylinder portion 305 is moved to slide between a conducting position shown by bold lines in FIG. 27 and a breaking position shown by imaginary lines in FIG. 27.

According to the above-described constitution, the pair of rod terminals 303 and 304 can electrically be connected by disposing the connection cylinder portion 305 at the conducting position by operating the operating lever member 307 and the pair of rod terminals 303 and 304 can electrically be broken by disposing the connection cylinder portion 305 at the breaking position by operating the operating lever member 307. That is, in order to move to slide the connection cylinder portion 305, the operating lever member 307 is connected to the connection cylinder portion 305, a fulcrum of force is constituted by one end side (lower end side) of the operating lever member 307, a force exerting point of the force is constituted by other end side (upper end) of the operating lever member 307 and the connection cylinder portion 305 can be moved by small operating force by utilizing the principle.

However, it is necessary to provide the operating lever member 307 rotatably supported by the connection cylinder portion 305 and move the upper end side of the operating lever 307 (grub portion 309) in parallel with sliding movement of the connection cylinder portion 305 and therefore, there poses a problem that the apparatus is large-sized.

In this case, in order to resolve large-sized formation of the apparatus, there is conceivable a constitution in which a movable plug is provided to be simply able to insert and extract to and from an apparatus main body, a pair of terminals are connected via a conductive portion of the movable plug by inserting the movable plug into the apparatus main body and the pair of terminals are broken by drawing the movable plug from the apparatus main body. However, according to such an apparatus, it is necessary to prevent erroneous insertion by which the movable plug is inserted to the apparatus main body not at a regular rotational position. That is, because according to a constitution in which the movable plug is locked at a circuit closed position, there is a concern of causing inconvenience that the movable plug cannot be locked unless the movable plug is inserted at the regular rotational position, or according to a constitution in which the movable plug is brought into proper contact with the terminal at an inner portion only at a proper rotational position, there is a concern of bringing about various inconveniences of causing contact failure, terminal destruction and the like. Further, according to such an apparatus, when the movable plug is simply inserted into the apparatus main body, large operational force is needed and therefore, a guide groove is provided on the side of the apparatus main body and a projection capable of being inserted into the guide groove is provided at the movable plug, respectively, further, there is provided a guide portion for rotation inclined in a skewed depth direction relative to a direction orthogonal to an inserting direction at a section of the guide groove from a position before finishing to insert the movable plug to a position of finishing to insert the movable plug. Further, it is conceivable that after inserting the movable plug into the apparatus main body to some degree, the movable plug is inserted while rotating the movable plug by operating to rotate the movable plug (convert rotational force into inserting force), thereby, the movable plug is inserted thereinto by small operational force.

However, according to the constitution having the operation of inserting the movable plug and the operation of rotating the movable plug, there is a possibility that an operator misunderstands that the operation has been finished at a time point of finishing the operation of inserting the movable plug and stops operating the operation of the movable plug. Further, when the final operation of rotating the movable plug is not carried out in this way, there poses a problem that there is brought about an incompletely fitted state in which the conductive portion and the terminal cannot firmly be fitted to each other.

There is another related circuit breaking apparatus of this kind disclosed in Japanese Patent Laid-Open No. 144429/1998 shown in FIG. 28 and FIG. 29.

As shown by FIG. 28 and FIG. 29, the circuit breaking apparatus 400 is constituted by an apparatus main body 401 and a movable plug 402 provided attachably and detachably to the apparatus main body 401. The apparatus main body 401 is provided with a pair of female terminals 403 and one of the pair of female terminals 403 is electrically connected to a load portion and other thereof is electrically connected to a power source portion, respectively. A plug insertion hole 404 is formed at a surrounding of the pair of female terminals 403 of the apparatus main body 401 and a pair of guide grooves 405 are formed on left and right sides of an outer periphery of the plug insertion hole 404.

The movable plug 402 is provided with an operating lever 407 provided with a pair of projections 406 at left and right side faces thereof, a plug main body 409 rotatably provided to the operating lever 407 via a rotation support shaft 408 and a pair of male terminals 411 fixed to the plug main body 109 and electrically connected thereto by a bus bar 410.

An operator grubs the operating lever 407, matches the pair of projections 406 to the pair of guide grooves 405 of the apparatus main body 401 and inserts the plug main body 409 into the plug insertion hole 404 of the apparatus main body 401. Then, by a stroke of inserting the movable plug 402, the male terminals 411 are inserted into the female terminals 403 and an interval between the pair of female terminals 403 are electrically connected by the pair of male terminals 411 and the bus bar 410 to thereby bring a power source circuit into a conductive state. Further, the movable plug 402 mounted to the apparatus main body 401 is drawn from the plug insertion hole 404 of the apparatus main body 401. Then, by a stroke of drawing the movable plug 402, the pair of male terminals 411 are detached from the pair of female terminals 403 and the interval between the pair of female terminals 403 is broken to thereby bring the power source circuit into a broken state.

Meanwhile, in the case in which there is a capacitor or the like at the load portion and when the power source circuit is broken by the circuit breaking apparatus 400, a charged state is maintained at the capacitor or the like of the load portion. Therefore, when maintenance or the like is carried out, it is necessary to discharge the capacitor or the like of the load portion, however, the above-described circuit breaking apparatus 400 is not provided with discharging means. Therefore, it is necessary to separately provide discharging means for connecting the load portion to the ground in a circuit broken state and releasing the load portion from the ground in a circuit conducted state at the power source circuit.

SUMMARY OF THE INVENTION

Hence, the invention has been carried out in order to resolve the above-described problem and it is an object thereof to provide a circuit breaking apparatus which is small-sized, inexpensive and capable of preventing terminals from being melted by arc discharge without using two relay switches and a control circuit thereof.

Another object of the present invention is to provide a circuit breaking apparatus constituting compact formation of the apparatus and capable of preventing erroneous insertion of a movable plug.

Another object of the present invention is to provide a circuit breaking apparatus capable of discharging a capacitor or the like of a load portion when the circuit breaking apparatus is brought into a circuit broken state from a circuit conducted state.

Another object of the present invention is to provide a circuit breaking apparatus capable of preventing leakage current or the like from being caused by arc discharge of a sacrifice electric pole.

Another object of the present invention is to provide a circuit breaking apparatus capable of making the apparatus compact, achieving a reduction in operational force of a movable plug, further, preventing an incompletely fitted state by incompletely inserting the movable plug from being brought about.

In order to solve the aforesaid object, the invention is characterized by having the following arrangement. (1) A circuit breaking apparatus comprising: a apparatus body; a load side terminal connected to a load portion and provided in the apparatus body; a power source side terminal connected to a power source portion and provided in the apparatus body; a sacrifice electrode portion connected to the power source side terminal and provided in the apparatus body; and a movable plug including a conductive portion and movable with respect to the apparatus body between a circuit opened position in which the movable plug does not electrically connect the load side terminal to the power source side terminal and a circuit closed position in which the movable plug electrically connects the load side terminal to the power source side terminal, wherein the load side terminal, the power source side terminal and the sacrifice electrode portion are shifted in a direction of moving the movable plug such that when the movable plug is moved from the circuit opened position to the circuit closed position, the conductive portion is brought into contact with the load side terminal, the sacrifice electrode portion and the power source side terminal in order. (2) The circuit breaking apparatus according to (1), wherein the sacrifice electrode portion includes a first sacrifice electric pole electrically connected to the power source side terminal through a resister, and a second sacrifice electric pole electrically directly connected to the power source side terminal, and when the movable plug is moved from the circuit opened position to the circuit closed position, the movable plug is firstly brought into contact with the first sacrifice electric pole and secondly brought into contact with the second sacrifice electric pole. (3) The circuit breaking apparatus according to (1), wherein the sacrifice electrode portion is electrically directly connected to the power source side terminal. (4) The circuit breaking apparatus according to (1), wherein a first face of the conductive portion firstly brought into contact with the sacrifice electrode portion and a second face of the conductive portion brought into contact with the power source side terminal, differ from each other. (5) The circuit breaking apparatus according to (4), wherein the conductive portion includes a side face which extends along the direction of moving the movable plug and corresponds to the first face and a tapered face on a front end thereof corresponding to the second face. (6) The circuit breaking apparatus according to (1), wherein the sacrifice electrode portion includes a sacrifice electric pole contactable with the conductive portion and an elastic arm portions connecting the sacrifice electric pole with the power source side terminal. (7) The circuit breaking apparatus according to (5), wherein the sacrifice electrode portion includes a sacrifice electric pole contactable with the conductive portion and an elastic arm portions connecting the sacrifice electric pole with the power source side terminal, and the sacrifice electric pole is elastically slidable on the side face of the conductive portion. (8) A circuit breaking apparatus comprising: an apparatus body; first and second terminals provided in the apparatus body, respectively; a movable plug including a conductive portion and movable with respect to the apparatus body between a circuit opened position in which the movable plug does not electrically connect the first terminal to the second terminal and a circuit closed position in which the movable plug electrically connects the first terminal to the second terminal, a guide groove provided at one of the apparatus body and the movable plug; and a projection insertable into the guide groove and provided at the other of the apparatus body and the movable plug, wherein the movable plug is inserted into the apparatus body only when the projection is inserted into the guide groove. (9) The circuit breaking apparatus according to (8), wherein the first and second terminals have a tubular cylindrical shape, and the conductive portion is a cylindrical rod insertable into the first and second terminals, respectively, so that the conductive portion is electrically connected with the first and second terminals. (10) The circuit breaking apparatus according to (9), wherein the guide groove has a rotation guide portion extending to a depth side in a direction skewed to a direction orthogonal to a direction of inserting the movable plug, and when the conductive portion is in contact with the first and second terminals, the projection is slid along the rotation guide portion. (11) The circuit breaking apparatus according to (10), wherein the movable plug includes an operation lever to which the projection or the guide grooves is provided and which rotatably supports the conductive portion. (12) The circuit breaking apparatus according to (8), wherein the guide groove includes a projection pickup portion having a large width on a side of an insertion port of the apparatus body firstly inserted with the projection and the width is gradually narrowed toward the insertion depth. (13) The circuit breaking apparatus according to (8), wherein the guide groove including: a projection pickup portion including a first end portion having a width three to six times as large as a width of the projection on a side of an insertion port of the apparatus body, and a second end portion having a width slightly wider than the width of the projection, the width of the projection pickup portion being gradually narrowed from the first end portion toward the second end portion; a straight advancement guide portion having a constant width slightly larger than the width of the projection and extending in an insertion direction of inserting the movable plug, one end thereof being communicated with the second end portion; and a rotation guide portion extending to a depth side in a direction skewed to a direction orthogonal to the insertion direction, and communicated with the other end of the straight advancement guide. (14) The circuit breaking apparatus according to (8), wherein the guide groove includes a rotation guide portion extending in a skewed depth direction relative to a direction orthogonal to a direction of inserting the movable plug, and a rotation introducing guide portion having a large radius of curvature in compared with that of the rotation guide portion, and when the movable plug is moved from the circuit opened position toward the circuit closed position, the projection is moved from a side of the rotation guide portion toward the rotation introducing guide portion. (15) The circuit breaking apparatus according to (14), wherein when the conductive portion is in contact with the first and second terminals, the projection is slid along the rotation guide portion. (16) The circuit breaking apparatus according to (8), wherein the guide groove includes a rotation guide portion extending in a skewed depth direction relative to a direction orthogonal to a direction of inserting the movable plug, and a rotation introducing guide portion having a large taper angle relative to the direction orthogonal to the direction of inserting the movable plug, and when the movable plug is moved from the circuit opened position toward the circuit closed position, the projection is moved from a side of the rotation guide portion toward the rotation introducing guide portion. (17) The circuit breaking apparatus according to (16), wherein when the conductive portion is in contact with the first and second terminals, the projection is slid along the rotation guide portion. (18) The circuit breaking apparatus according to (8), wherein the guide groove has a curved shape whose a radius of curvature varies. (19) A circuit breaking apparatus comprising: an apparatus body; a load side terminal connected to a load portion and provided in the apparatus body; a ground side terminal which is connected to the ground, provided in the apparatus body, and movable between a contact position in which the ground side terminal is in contact with the load side terminal and a separated position in which the ground side terminal is separated from the load side terminal; a power source side terminal connected to a power source portion and provided in the apparatus body; a movable plug including a conductive portion and movable with respect to the apparatus body between a circuit opened position in which the conductive portion is not in contact with the power source side terminal and a circuit closed position in which the conductive portion is in contact with the load side terminal and the power source side terminal; and an urging member for urging the ground side terminal to the contact position, wherein the ground side terminal is in the contact position when the movable plug is in the circuit opened position, and wherein the ground side terminal is moved to the separated position against urge force of the urging member in when the movable plug is moved from the circuit opened position to the circuit closed position. (20) The circuit breaking apparatus according to (19), wherein the ground side terminal includes a pair of contact portion holders opposed each other with respect to a movement center axis of the movable plug, in the contact position, the pair of contact portion holders are arranged on a movement locus of the movable plug, and in the separated position, the pair of contact portion holders are moved in directions separating from each other by a press force of the movable plug and arranged at a position for slidably contact with the conductive portion of the movable plug. (21) The circuit breaking apparatus according to (19), wherein the apparatus body is provided with a sacrifice electrode electrically connected to the power source side terminal, and when the movable plug is moved from the circuit opened position to the circuit closed position, the conductive portion is brought into contact with the load side terminal, the sacrifice electrode and the power source side terminal in order. (22) The circuit breaking apparatus according to (19), wherein the urging member is a spring. (23) A circuit breaking apparatus comprising: an apparatus body; a load side terminal connected to a load portion and provided in the apparatus body; a power source side terminal connected to a power source portion and provided in the apparatus body; a sacrifice electrode which is connected to the power source side terminal, provided in the apparatus body and interposed between the load side terminal and the power source side terminal; a movable plug including a conductive portion and movable with respect to the apparatus body between a circuit opened position in which the movable plug does not electrically connect the load side terminal with the power source side terminal and a circuit closed position in which the movable plug electrically connects the load side terminal with the power source side terminal; and insulative caps provided at the load side terminal and the power source side terminal, respectively, wherein when the movable plug is moved from the circuit opened position to the circuit closed position, the conductive portion is brought into contact with the load side terminal, the sacrifice electrode and the power source side terminal in order. (24) The circuit breaking apparatus according to (23), wherein the insulative cap is provided at one end of the load side terminal facing to the sacrifice electrode. (25) The circuit breaking apparatus according to (23), wherein the insulative cap is provided at one end of the power source side terminal facing to the sacrifice electrode. (26) The circuit breaking apparatus according to (23), wherein each of the load side terminal and the power source side terminal includes a cylinder ring portion and a multiple point contact spring member arranged at an inner peripheral face of the cylinder ring portion, and the multiple point contact spring member is fixed to the cylinder ring portion by the insulative cap.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A through 1C show a first embodiment of the invention in which FIG. 1A is a front view of a circuit breaking apparatus, FIG. 1B is a right side view of the circuit breaking apparatus and FIG. 1C is a bottom view of the circuit breaking apparatus.

FIG. 2 shows the first embodiment of the invention and is an inner face view of a cover.

FIG. 3 shows the first embodiment of the invention and is an inner face view of a base member fixed with respective terminals and electric pole parts.

FIG. 4 shows the first embodiment of the invention and is a sectional view taken along a line A--A of FIG. 1B.

FIG. 5 shows the first embodiment and is a front view of a movable plug.

FIG. 6 shows the first embodiment of the invention and is a circuit diagram of a power source circuit mounted with the circuit breaking apparatus.

FIG. 7 shows the first embodiment and is an inner face view of the base member showing a state in which the movable plug is brought into contact with a sacrifice electric pole with resistor.

FIGS. 8A and 8B show the first embodiment of the invention in which FIG. 8A is a view showing a state in which a conductive portion of the movable plug is brought into contact with the sacrifice electric pole with resistor and FIG. 8B is a view showing a state in which the conductive portion of the movable plug is brought into contact with a through sacrifice electric pole.

FIGS. 9A through 9C show a second embodiment of the invention in which FIG. 9A is a front view of a circuit breaking apparatus, FIG. 9B is a right side view of the circuit breaking apparatus and FIG. 9C is a bottom view of the circuit breaking apparatus.

FIG. 10 shows the second embodiment of the invention and is an inner face view of a cover.

FIG. 11 shows the second embodiment of the invention and is an inner face view of a base member fixed with respective terminals and electric pole parts.

FIG. 12 shows the second embodiment of the invention and is a sectional view taken along a line A--A of FIG. 9B.

FIG. 13 shows the second embodiment of the invention and is a front view of a movable plug.

FIG. 14 shows the second embodiment of the invention and is a circuit diagram of a power source circuit mounted with the circuit breaking apparatus.

FIG. 15 shows the second embodiment of the invention and is an inner face view of the base member showing a state in which a movable plug is disposed at a circuit opened position.

FIG. 16 shoes the second embodiment of the invention and is an inner face view of the base member showing a state in which a conductive portion of the movable plug is brought into contact with a sacrifice electric pole.

FIG. 17 shows the second embodiment of the invention and is an inner face view of the base member showing a state in which the conductive portion of the movable plug is disposed at a circuit closed position.

FIGS. 18A through 18C show the embodiment of the invention in which FIG. 18A is a sectional view of an essential portion of the circuit breaking apparatus showing a state in which the movable plug is inserted (erroneously inserted) at other than a regular rotational position, FIG. 18B is a sectional view of the essential portion of the circuit breaking apparatus showing a state in which the movable plug is inserted at the rotational position and FIG. 18C is a sectional view of the essential portion of the circuit breaking apparatus showing a state in which a projection of the movable plug is inserted up to a deepest position of a guide groove for straight advancement of a guide groove.

FIG. 19 shows the second embodiment of the invention and is a sectional view of a load side terminal.

FIG. 20 shows a third embodiment of the invention and is an inner face view of a cover.

FIG. 21 shows the third embodiment of the invention and is an inner face view of a base member fixed with respective terminals and electric pole parts.

FIG. 22 shows the third embodiment of the invention and is an inner face view of the base member showing a state in which a movable plug is disposed at a circuit opened position.

FIGS. 23A and 23B show the third embodiment of the invention in which FIG. 23A is an inner face view of the base member showing a state in which a projection of the movable plug is made to advance into a rotation introducing guide portion of a guide groove and FIG. 23B is a side view of the circuit breaking apparatus in the state.

FIGS. 24A and 24B shows the third embodiment of the invention in which FIG. 24A is an inner face view of the base member showing a state in which the projection of the movable plug is made to advance into a guide portion for rotation of the guide groove and FIG. 24B is a side view of the circuit breaking apparatus in the state.

FIG. 25 shows the third embodiment of the invention and is an inner face view showing a state in which a projection of the movable plug is inserted into a deepest position of the guide portion for rotation of the guide groove.

FIG. 26 is a circuit diagram of a circuit breaking apparatus according to a related example.

FIG. 27 is a sectional view of a circuit breaking apparatus of another related example.

FIG. 28 is a perspective view of a circuit breaking apparatus according to another related example.

FIG. 29 is a sectional view of the circuit breaking apparatus according to the related example of FIG. 28.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

An explanation will be given of embodiments of the invention in reference to the drawings as follows.

First Embodiment

FIGS. 1A through 8 show a first embodiment of the invention. FIG. 1A is a front view of a circuit breaking apparatus 1A. FIG. 1B is a right side view of the circuit breaking apparatus 1A. FIG. 1C is a bottom view of the circuit breaking apparatus 1A. FIG. 2 is an inner face view of a cover 105. FIG. 3 is an inner face view of a base member 104 to which respective terminals and electric pole parts are fixed. FIG. 4 is a sectional view taken along a line A--A of FIG. 1B. FIG. 5 is a front view of a movable plug 103. FIG. 6 is a circuit diagram of a power source circuit mounted with the circuit breaking apparatus 1A. FIG. 7 is an inner face view of the base member 104 showing a state in which the movable plug 103 is brought into contact with a sacrifice terminal with resistor 135. FIG. 8A is an outline view of an essential portion showing a state in which a conductive portion 141 of the movable plug 103 is brought into contact with the sacrifice electric pole 135 with resistor. FIG. 8B is an outline view of the essential portion showing a state in which the conductive portion 141 of the movable plug 103 is brought into contact with a through sacrifice electric pole 136.

As shown in FIG. 1 through FIG. 6, the circuit breaking apparatus 1A is constituted by an apparatus main body 102 and the movable plug 103 capable of being inserted into and drawn from the apparatus main body 102. As shown by FIG. 1, FIG. 3 and FIG. 4 in details, the apparatus main body 102 is constituted by the base member 104 and the cover 105 which are jointed together in a state of butting respective joint faces thereof, and has a shape of a substantially quadrangular prism as a whole. At inside of the apparatus main body 102 in the shape of the quadrangular prism, there are provided a parts containing chamber 106 and a plug inserting chamber 107 along a direction of a center axis C thereof. The parts containing chamber 106 and the plug inserting chamber 107 are communicated with each other via a conductive portion insertion hole 108. The plug inserting chamber 107 and the conductive portion insertion hole 108 are formed in a space in a shape of a circular cylinder centering on the center axis C of the apparatus main body 102. The movable plug 103 is inserted into the space with the center axis C of the apparatus main body 102 as an insertion center axis. A conductive portion 141 of the movable plug 103 is made to advance to the parts containing chamber 106 by passing through the conductive portion insertion hole 108.

One end of the plug inserting chamber 107 is opened to outside and the opened portion thereof constitutes a plug insertion port 109. The movable plug 103 can be inserted into the apparatus main body 102 and the inserted plug 103 can be drawn from the plug insertion port 109. A position at which the movable plug 103 is drawn from the plug insertion port 109 of the apparatus main body 102, constitutes a circuit opened position. A position at which the movable plug 103 is completely inserted into the apparatus main body 103 from the plug insertion port 109, constitutes a circuit closed position. According to the first embodiment, the movable plug 103 is provided movably between the circuit opened position and the circuit closed position by inserting and drawing the conductive portion 141 of the movable plug 103.

The plug insertion port 109 has a diameter slightly larger than a maximum diameter portion of an operating lever 140, mentioned below. The plug inserting chamber 107 is formed by a diameter slightly larger than a circuit cylinder supporting portion 140b of the movable plug 103. Two guide grooves 110 for guiding the movable plug 103 at positions opposed to each other by 180 degrees are provided at an inner peripheral face of the plug inserting chamber 107. Each of the guide grooves 110 is constituted by: a projection pickup portion 110a having a width several times as large as a projection 142 of the movable plug 103 at an opening position of the plug insertion port 109, the width being gradually narrowed from the plug insertion port 109 toward the deeper side; a guide portion 10b for straight advancement communicated with the projection pickup portion 110a at a deepest portion thereof, having a constant width to a degree of slightly wider than a width of the projection 142 of the movable plug and extended to the depth side toward a direction of the center axis C of the apparatus main body 102; and a guide portion 110c for rotation communicated with the straight advancement guide portion 10b at a deepest portion thereof, having a constant width slightly larger than the width of the projection 142 of the movable plug 103 and extended to the depth side in a direction skewed to a direction orthogonal to the center axis C of the apparatus main body 102.

A ground side terminal 111, a load side terminal 112, a sacrifice electrode portion 114, and a power source side terminal 113 are contained in the parts containing chamber 106 in this order from the side of the plug insertion port of the movable plug 103. All of the terminals 111, 112 and 113 and the sacrifice electrode portion 114 are fixed to the base member 104.

The ground side terminal 111 is constituted by: a ground bus bar 115 arranged in a state of being brought into contact with an inner face of the base member 104; a pair of contact portion holders 117 made of insulators rotatably supported by a pair of support pin portions 116 and arranged on the left and on the right with the center axis of the apparatus main body 102 as a boundary; a pair of contact portions 118 fixed to the pair of contact portion holders 117 and brought into contact with the ground bus bar 115 regardless of a rotational position thereof; and a pair of ground springs 119 for urging the pair of contact portion holders 117 to the center side (contact position side) to be brought into contact with each other. That is, as shown by FIG. 3, in a state in which the conductive portion 141 of the movable plug 103 is not inserted between the pair of contact portion holders 117, the pair of contact portion holders 117 are brought into contact with each other by being exerted with spring force of the ground springs 119, and the pair of contact portions 118 are disposed at contact positions in contact with a cylinder ring 121 of the load side terminal 112. As shown by FIG. 7, in a state in which the conductive portion 141 of the movable plug 103 is inserted between the pair of contact portion holders 117, the pair of contact portion holders 118 are rotated in directions a of being separated from each other against the spring force of the respective ground springs 119 by press force of the movable plug 103, and the pair of contact portions 118 are disposed at separated positions separated from the cylinder ring portion 121 of the load side terminal 112. At the contact positions, the ground side terminal 111 and the load side terminal 112 are electrically connected. At the separated positions, the ground side terminal 111 and the load side terminal 112 are electrically broken.

One end side of the ground bus bar 115 is projected from a hole 105a of the cover 105 to outside and the projected portion constitutes a ground connection terminal 120. The power source circuit is grounded by using the ground connection terminal 120 (refer to FIG. 6).

The load side terminal 112 is constituted by the cylinder ring portion 111 made of a conductor arranged centering on the center axis C of the apparatus main body 102, a conductive multiple point spring member 122 which is arranged at an inner peripheral face of the cylinder ring portion 121 and elastically deformable in a direction of enlarging a diameter thereof and a resin cap 123 made of an insulator attached to the cylinder ring portion 121 and the multiple point spring member 122 on the side of the sacrifice electrode portion 114. The cylinder ring portion 121 is fixed to the base member 104 by screws 125 via a bracket 124. Further, by inserting the movable plug 103 into the cylinder ring portion 121, the movable plug 103 and the load side terminal 112 are electrically connected. The cylinder ring portion 121 is provided with an extended plate portion, the extended plate is projected to outside from a hole 104a of the base member 104 and the projected portion constitutes a load connecting terminal 126. By using the load connecting terminal 126, the load side terminal 121 is electrically connected to a load portion 127 (refer to FIG. 6).

Similar to the load side terminal, the power source side terminal 113 is constituted by a cylinder ring portion 128 made of a conductor arranged centering on the center axis C of the apparatus main body 102, a multiple point contact spring member 129 made of a conductor which is arranged at an inner peripheral face of the cylinder ring portion 128 and elastically deformable in a direction of enlarging a diameter thereof, and a resin cap 130 made of an insulator attached to the cylinder ring portion 128 and the multiple contact spring member 129 on the side of the sacrifice electrode portion 114. The cylinder ring portion 128 is fixed to the base member 104 by screws 132 via a bracket 131. Further, by inserting the movable plug 103 into the cylinder ring portion 128, the movable plug 103 and the power source side terminal 113 are electrically connected. The cylinder ring portion 121 is provided with an extended plate portion, the extended plate portion is projected to outside from a hole 104b of the base member 104 and the projected portion constitutes a power source connecting terminal 133. By using the power source connecting terminal 133, the power source side terminal 113 is electrically connected to a power source portion 134 (refer to FIG. 6).

The sacrifice electrode portion 114 is arranged between the load side terminal 112 and the power source side terminal 113 as described above and is constituted by two terminals of the sacrifice electric pole 135 with resistor and the through sacrifice electric pole 136. The sacrifice electric pole 135 with resistor and the through sacrifice electric pole 136 are arranged at positions shifted to the left and to the right separately from the center axis C of the apparatus main body 102. The sacrifice electric pole 135 with resistor is arranged more proximate to the load side terminal 112 than the through sacrifice electric pole 136. The sacrifice electric pole 135 with resistor and the through sacrifice electric pole 136 are supported by respective elastic arm portions 137 and 138 made of a conductor fastened together by the left and right screws 132 for fastening the power source side terminal 113 and are provided movably in directions (b, c arrow mark directions of FIG. 3) further separating from the center axis C of the apparatus main body 102 by elastic deformation of the respective elastic arm portions 137 and 138. A resistor 139 is provided at a middle of the elastic arm portion 137 on the side of the sacrifice electric pole 135 with resistor. The sacrifice electric pole 135 with resistor is electrically connected to the power source side terminal 113 via the resistor 139. The elastic arm portion 138 on the side of the through sacrifice electric pole 136 is not provided with a resistor and the through sacrifice electric pole 136 is electrically connected to the power source side terminal 113 without interposing a resistor therebetween (refer to FIG. 6).

As shown by FIG. 5, the movable plug 103 is constituted by the operating lever 140 and the conductive portion 141 rotatably supported by the operating lever 140. The operating lever 140 is constituted by a handle portion 140a which is formed by an insulator of synthetic resin or the like and can be picked up by the finger of the operator and a circular cylinder supporting portion 140b provided integrally with the handle portion 140a for rotatably supporting the conductive portion 141. The circular cylinder supporting portion 140b is provided with the projections 142 at positions opposed to each other by 180 degrees. The conductive portion is formed by a conductive member and is provided with a shape of a slender circular cylindrical rod. A side face 141a in the shape of the circular cylindrical rod is extended along the moving direction and is formed with a tapered face 143 a diameter of which is contracted toward a front end thereof at its front end side.

Next, an explanation will be given of circuit operating and closing operation of the power source circuit by the above-described circuit breaking apparatus 1A. A state in which the movable plug 103 is not inserted into the apparatus main body 102, constitutes the circuit opened position of the movable plug 103. When the movable plug 103 at the circuit opened position is inserted from the plug insertion port 109 of the apparatus main body 102 with the front end face of the conductive portion 141 as a head thereof, the conductive portion 141 of the movable plug 103 is made to advance from the conductive portion insertion hole 108 to the parts containing chamber 106 so that the front end face of the conductive portion 141 is firstly brought into contact with the pair of contact point portion holders 117. When the movable plug 103 is inserted against spring force of the pair of arm springs 119 for urging the pair of contact portion holders 117, the pair of contact portion holders 117 are rotated centering on the support pin portions 116 against the spring force of the pair of arm springs 119 to thereby permit insertion of the conductive portion 141 and the pair of contact portions 118 are separated from the cylinder ring portion 121 to thereby electrically break the ground side terminal 111 and the load side terminal 112.

When the movable plug 103 is inserted further from the position, the front end of the conductive portion 141 is inserted into the cylinder ring portion 121 of the load side terminal and the side face 141a in a circumferential shape of the conductive portion 141 is brought into contact with the ring-like multiple point contact spring member 122 at inside of the cylinder ring portion 121 in a state of being exerted with elastic force. When the front end of the conductive portion 141 is inserted up to a position of coming out from the cylinder ring portion 121, in the case in which a rotational position of inserting the movable plug 103 is correct, the pair of projections 142 of the operating lever 140 are made to advance to the projection pickup portions 110a of the guide grooves 110 of the apparatus main body 102.

When the front end of the conductive portion 141 of the movable plug 103 is made to advance through the cylinder ring portion 121 of the load side terminal 112, as shown by FIG. 7, the front end of the conductive portion 141 is brought into contact with the sacrifice electric pole 135 with resistor. Then, the sacrifice electric pole 135 with resistor and the load side terminal 112 are electrically connected via the conductive portion 141. As a result, the power source portion 134 and the load portion 127 are electrically connected and therefore, current is made to flow from the power source portion 134 to a capacity or the like of the load portion 127, however, only small current is made to flow since the power source portion 134 is connected to the load portion 127 via the resistor 139. That is, abruptly increased current is not made to flow between the conductive portion 141 and the sacrifice electric pole 135 with resistor.

Next, the conductive portion 141 of the movable plug 103 is brought into contact with the through sacrifice electric pole 136. Then, although the power source portion 134 is electrically connected to the load portion 127 directly without interposing a resistor therebetween, since current to some degree flows by previous electricity conduction, abruptly increased current is not made to flow between the conductive portion 141 and the through sacrifice electric pole 136. Further, when th