EP0827173B1 - Circuit breaker - Google Patents
Circuit breakerInfo
- Publication number
- EP0827173B1 EP0827173B1 EP96906042A EP96906042A EP0827173B1 EP 0827173 B1 EP0827173 B1 EP 0827173B1 EP 96906042 A EP96906042 A EP 96906042A EP 96906042 A EP96906042 A EP 96906042A EP 0827173 B1 EP0827173 B1 EP 0827173B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- handle
- movable contact
- handle arm
- open position
- contact element
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
- H01H71/10—Operating or release mechanisms
- H01H71/50—Manual reset mechanisms which may be also used for manual release
- H01H71/501—Means for breaking welded contacts; Indicating contact welding or other malfunction of the circuit breaker
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H73/00—Protective overload circuit-breaking switches in which excess current opens the contacts by automatic release of mechanical energy stored by previous operation of a hand reset mechanism
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
- H01H71/10—Operating or release mechanisms
- H01H71/50—Manual reset mechanisms which may be also used for manual release
- H01H71/52—Manual reset mechanisms which may be also used for manual release actuated by lever
- H01H71/522—Manual reset mechanisms which may be also used for manual release actuated by lever comprising a cradle-mechanism
- H01H71/525—Manual reset mechanisms which may be also used for manual release actuated by lever comprising a cradle-mechanism comprising a toggle between cradle and contact arm and mechanism spring acting between handle and toggle knee
Definitions
- This invention relates to a circuit interrupter.
- Fig. 11 is a sectional view illustrating a conventional circuit interrupter disclosed in Japanese Utility Model Publication No. 1-42286.
- the reference numeral 1 is a cover and 2 is a base, both of which are made of a synthetic resin.
- 3 is a housing composed of the cover 1 and the base 2
- 4 is a stationary contact secured to the base 2 and having at one end thereof a terminal portion 5 for allowing an external conductor (not shown) to be connected thereto and at the upper surface of the other end thereof a stationary contact element 6.
- movable contact 7 is a movable contact having a movable contact element 8 opposing to the stationary contact element 6
- 9 is a movable contact arm pivotally supporting the movable contact 7 by a pivot pin 10
- 11 is a contact pressure spring disposed between the movable contact arm 9 and the movable contact 7 for always biasing the movable contact 7 toward the stationary contact element 6
- 12 is a crossbar made of an electrically insulating material for connecting each of the movable contact arms 9 disposed in parallel for all of the poles.
- 13 is an arc extinguishing device for extinguishing an electric arc generated between the contact elements 6 and 8 and is provided with a plurality of arc extinguishing magnetic plates 15 inside of a pair of arc extinguishing side plates 14.
- 16 is a lower link pivotally supported at its one end to the movable contact arm 9 by a shaft 17, 18 is an upper link pivotally connected at one end to the other end of the lower link 16 and at the other end to a cradle 19 by shafts 20 and 21, respectively.
- 22 is a toggle link mechanism composed of the lower link 16, the upper link 18 and the shaft 20, the shaft 20 serving as a knee.
- 23 is a handle arm supported at its one end (not shown) to be pivotable to a predetermined position relative to the toggle link mechanism 22, 24 is a toggle spring made of a synthetic resin and operable from the exterior of the cover 1 and is interconnected to the handle arm 23.
- 27 is a bimetal connected to the movable contact 7
- 28 is a stationary iron core secured to the bimetal
- 29 is a movable iron core disposed opposite to the stationary iron core
- 30 is a trip bar rotatable and having the movable iron core 29 secured thereto
- 31 is a rotatable latch usually engaged at one end by the cradle 19 and at the other end by the trip bar
- 32 is a cradle shaft for rotatably supporting the cradle 19
- 33 is a stopper for latching the cradle 19 upon the tripping and is engaged with a frame 34 to be secured thereto.
- the frame 34 also supports the support point or the fulcrum for positioning the cradle shaft 32 and for pivoting the latch 31.
- Japanese Patent Publication No. 1-39176 discloses a conventional circuit interrupter in which the operating lever (corresponding to the handle arm) and the movable contact assembly engages each other when the contact elements are welded together so as not to permit the handle to move into the open position.
- USB-A-5 304 765" discloses a circuit interrupter according to the preamble of claim 1.
- the circuit interrupter comprises, within an insulating housing composed of a base and a cover, a stationary contact, a movable contact separable from and opposing to said stationary contact, a toggle mechanism for driving said movable contact, a handle arm pivotally supported at a predetermined position relative to said toggle mechanisms, a trip device responsive t an overcurrent to actuate said toggle mechanism, and is characterized by a prevention portion engageable with said handle arm for preventing said handle to move into the open position. This allows the handle to be prevented from moved to the open position and the handle arm to be made relatively small-sized
- the prevention portion may be a cam portion disposed in a handle side link of the toggle link mechanism for engaging with the handle arm upon the welding of said movable contact and said stationary contact to prevent the handle from moving into the open position. This allows the handle to be prevented from moving in the direction of the open position and the handle arm to be made relatively small.
- the prevention portion which engages the handle arm of the handle side link of the toggle mechanism may be formed as an arc-shaped cam portion having its center on the pivot point of the handle side link. Since the pivot point of the handle side link and the center of the cam potion coincide, even when the handle side link pivots, the handle does not move in the direction toward the open position beyond the position in which it engages the cam portion, so that the welding of the contact elements can be clearly indicated.
- the cam portion which engages the handle arm of the handle side link may comprise a second cam portion, which engages the handle arm in the first period of the handle moving process in which the handle is being moved toward the open position upon the welding of the movable contact element to the stationary contact element, and a first cam portion, which engages the handle arm in the last period of the handle moving process in which the handle is being moved toward the open position upon the welding of the movable contact element to the stationary contact element.
- the bent engaging portion of the handle arm engages the second cam portion of the handle side link, thereby to cause the connection portion between the handle side link and the movable contact side link to quickly collapse, whereby the opening operation can be made more reliable.
- the movable contact can be pulled up by the clockwise moment to separate the contact elements. The further movement of the handle arm causes engagement with the first cam portion, whereby the handle is prevented from further moving toward the open position.
- the cam portion which engages the handle arm of the handle side link may be defined by a first cam portion of an arc having its center on the fulcrum of the handle side link and a second cam portion of an arc having its center at a position shifted from the fulcrum of the handle side link. Therefore, when the circuit interrupter is moving the handle from the closed position to the open position in the counterclockwise direction, the bent engaging portion of the handle arm engages the second cam portion of the handle side link, thereby to cause the connection portion between the handle side link and the movable contact side link to quickly collapse, whereby the opening operation can be made more reliable.
- the movable contact can be pulled up by the clockwise moment to separate the contact elements. The further movement of the handle arm causes engagement with the first cam portion, whereby the handle is prevented from further moving toward the open position.
- a further disclosed embodiment of the circuit interrupter may comprise, within an insulating housing composed of a base and a cover, a stationary contact, a movable contact separable from and opposing to said stationary contact, a cross bar connecting one end of the movable contact together, a toggle mechanism for driving the movable contact, a handle arm pivotably supported at a predetermined position relative to said toggle mechanism, a handle moving in relation to the handle arm and a trip device responsive to an overcorrect to actuate said toggle mechanism, and may be characterized by a stopper for engaging between the cross bar and the handle arm upon the welding of the movable contact element of the movable contact to the stationary contact element of the stationary contact for preventing the handle to move into the open position. This allows the handle to be prevented from moved to the open position and made relatively small-sized, and the stopper to abut against the rigid cross bar which is not easily destroyed, so that the mechanism is strong.
- a torsion spring for causing the stopper to always engage the handle arm may be provided.
- the handle arm is always biased in the clockwise direction to ensure the movement of the handle into the direction of the closed position, whereby position of the contact element of the circuit interrupter is ensured to precisely correspond to the state indicated by the handle.
- Fig. 1 is a sectional side view of a circuit interrupter which is the first embodiment of the present disclosure showing the closed position with its one portion cut away to show the interior.
- Fig. 2 is a sectional side view of the main portion showing the open position of the circuit interrupter shown in Fig. 1
- Fig. 3 is a sectional side view of the main portion showing the tripped position of the circuit interrupter shown in Fig. 1.
- 40 is a cover and 41 is a base, both made of a synthetic resin.
- 42 is a housing composed of the cover 40 and the base 41
- 43 is a stationary contact secured to the base 41 and having a stationary contact element 43a.
- 44 is a movable contact having a movable contact element 44a opposing to the stationary contact element 43a and is pivotally supported by a pivot pin 45.
- 46 is a cross bar made of an insulating material connected to one end of the respective movable contacts 44 provided at each poles.
- 47 is a contact pressure spring disposed between the movable contact 44 and the cross bar 46 for always biasing the movable contact 44 toward the stationary contact element 43a.
- 48 is a flexible conductor with its one end connected to the movable contact 44 and the other end connected to a trip device (not shown).
- arc extinguishing device for extinguishing an electric arc generated between the contact elements 43a and 44a and is provided with a plurality of arc extinguishing magnetic plates 51 disposed within a pair of arc extinguishing side plates 50.
- 52 is a movable contact side link (hereinafter simply referred to as a lower link) pivotally connected at one end to the cross bar 46 by a shaft 53
- 54 is a handle side link (herein after simply referred to as an upper link) pivotally connected at one end to the other end of the lower link 52 and at the other end to a cradle 55 by shafts 56 and 57
- a prevention portion is provided at the upper link 54.
- This prevention portion is defined by a cam portion 54a of an arc section having a radius of R and a center at the center of the shaft 57 which is the fulcrum of the upper link 54.
- 58 is a toggle link mechanism composed of the lower link 52, the upper link 54 and the shaft 56, the shaft 56 being a knee portion.
- 59 is a handle arm having a bent engaging portion 59a and pivotally supported at one end 59b as a pivot point on an unillustrated frame so as to be pivotable into a predetermined position relative to the toggle link mechanism 58.
- 60 is a toggle spring connected at one end to the handle arm 59 through a spring holding pin 61 and the other end to the shaft 56.
- 62 is a handle made of a synthetic resin and operable from the outside of the cover 40 cooperable with the handle arm 59.
- 63 is a latch, which comprises a latch engaging portion 63a engaging the cradle 55 and a recess portion 63b in which a latch support shaft 64 is received, and engageable with the trip device (not shown) to be rotated about the latch support shaft 64.
- 65 is a cradle support shaft pivotally supported by the unillustrated frame, and 66 is a stopper pin for the upper link 54 and the movable contact 44.
- connection point between the cradle 55 and the upper link 54 or the point of the shaft 57 is moved beyond the line of action of the toggle spring 60, so that the toggle link mechanism 58 collapses due to the spring force of the toggle spring 60, and the movable contact element 44a is separated from the stationary contact element 43a for each pole concurrently, thereby to become the tripped position shown in Fig. 3.
- Fig. 4 illustrates the state in which a pulse-like massive current for example flows in the closed position so that a welding phenomenon took place between the stationary contact element 43a and the movable contact element 44a while the engagement between the cradle 55 and the latch 63 is not released, whereby the movable contact element 44a fails to separate from the stationary contact element 43a.
- the toggle link mechanism 58 is held in the closed position, and when the handle 62 is moved in the counterclockwise direction toward the open position in order to put the circuit interrupter in the open position as required for the inspection and maintenance as illustrated in Fig. 4, then the toggle spring 60 is expanded to allow the handle arm 59 to be rotated in the counterclockwise direction into the open position.
- the arrangement may be such that the bent engaging portion 59a of the handle arm 59 abuts against and engages the lower link of the toggle link mechanism 58 maintained at the closed position.
- the handle arm can be made smaller as compared to that in the case where the movable contact assembly and the handle arm abut against and engage with each other.
- Fig. 5 is a sectional side view of the circuit interrupter which is the second embodiment of the present disclosure with its one portion removed to show the interior thereof and illustrates the state in which the handle is moved toward the open position while the contact elements of the circuit interrupter are welded to each other.
- Fig. 6 is an enlarged sectional side view of the main portion of the circuit interrupter shown in Fig. 5 with its contact elements welded and with its handle moved in the open position.
- 100 is an upper link, the configuration of which cam portion engaging the bent engaging portion 59a of the handle arm 59 comprises a first cam portion 100a having a radius of curvature R1 with its center at the center C1 of the shaft 57 and a second cam portion 100b having a radius of curvature R2 with its center at a position as the center C2 shifted by a distance L from the center C1 of the shaft 57 toward the lower link 52.
- the upper link 100 rotates in the direction of collapse and the first cam portion 100a and the bent engaging portion 59a engage with each other, the upper link 100 rotates until the upper link 100 lifts up the movable contact 44, but the handle 62 prevents the upper link 100 to move in the direction of closed beyond the point at which it abuts the cam portion 100a.
- Fig. 8 is a sectional side view of the circuit interrupter in the closed position which is the third embodiment of the present disclosure, with one portion thereof removed to show the interior.
- 1 ⁇ 66 are similar components to those of the above described first embodiment and their explanation is omitted.
- 70 is a stopper, which is pivotally supported by the stopper support shaft 65 of the cradle 55 and having an arm portion 70a at one end and having a stopper shaft 71 for engaging with the bent engaging portion 59a of the handle arm 59 secured at the other end.
- Fig. 9 illustrates the state in which a pulse-like massive current for example flows in the closed position so that a welding phenomenon took place between the stationary contact element 43a and the movable contact element 44a while the engagement between the cradle 55 and the latch 63 is not released, whereby the movable contact element 44a fails to separate from the stationary contact element 43a.
- the toggle spring 60 is expanded to allow the handle arm 59 to be rotated in the counterclockwise direction into the open position (see Fig. 9).
- the bent engaging portion 59a of the handle arm 59 causes the rotation of the shaft 71 which is in abutment with the bent engaging portion 59a of the handle arm 59 in the counterclockwise direction, and causes the arm portion 70a of the stopper 70 to rotate in the counterclockwise direction until it abuts against and engages a projection portion 46a of the structurally rigid cross bar 46, whereby the handle arm 59 is prevented from being further moved toward the open position.
- the handle arm can be made smaller than that used in the conventional design in which the movable contact assembly and the handle arm abut against and engage with each other.
- Fig. 10 is a sectional side view of a circuit interrupter.
- 72 is a torsion spring, which is connected to the stopper shaft 71 for causing the stopper shaft 71 to always abut against the bent engaging portion 59a of the handle arm 59 thereby to always biasing the stopper 70 in the clockwise direction.
- the biasing force of the torsion spring 72 acting on the stopper 70 is a biasing force causing the handle arm 59 and the handle 62 to rotate in the clockwise direction.
- the present invention has been made in order to solve the described problem with prior art devices, and advantageously provides an arrangement in which the handle cannot be moved to the open position when the movable contact element and the stationary contact element are welded together and in which the handle arm is relatively small.
- Another advantage is to provide an arrangement in which the handle cannot be moved to the open position when the movable contact element and the stationary contact element are welded together, the handle arm is relatively small and in which the mechanism is strong.
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Abstract
Description
- This invention relates to a circuit interrupter.
- Fig. 11 is a sectional view illustrating a conventional circuit interrupter disclosed in Japanese Utility Model Publication No. 1-42286. In this figure, the
reference numeral 1 is a cover and 2 is a base, both of which are made of a synthetic resin. 3 is a housing composed of thecover 1 and thebase base 2 and having at one end thereof aterminal portion 5 for allowing an external conductor (not shown) to be connected thereto and at the upper surface of the other end thereof astationary contact element 6. 7 is a movable contact having amovable contact element 8 opposing to thestationary contact element movable contact 7 by apivot pin movable contact arm 9 and themovable contact 7 for always biasing themovable contact 7 toward thestationary contact element movable contact arms 9 disposed in parallel for all of the poles. 13 is an arc extinguishing device for extinguishing an electric arc generated between thecontact elements magnetic plates 15 inside of a pair of arc extinguishingside plates 14. 16 is a lower link pivotally supported at its one end to themovable contact arm 9 by ashaft lower link 16 and at the other end to acradle 19 byshafts lower link 16, theupper link 18 and theshaft 20, theshaft 20 serving as a knee. 23 is a handle arm supported at its one end (not shown) to be pivotable to a predetermined position relative to thetoggle link mechanism cover 1 and is interconnected to thehandle arm 23. 27 is a bimetal connected to themovable contact bimetal stationary iron core movable iron core 29 secured thereto, 31 is a rotatable latch usually engaged at one end by thecradle 19 and at the other end by thetrip bar cradle cradle 19 upon the tripping and is engaged with aframe 34 to be secured thereto. Theframe 34 also supports the support point or the fulcrum for positioning thecradle shaft 32 and for pivoting thelatch 31. - The operation will now be described. If the contact elements are in the open position as shown in Fig. 12, when the
handle 26 is moved to the closed position (to the right), thetoggle mechanism 22 is extended to bring themovable contact element 8 into contact with thestationary contact element 6 which is the closed position shown in Fig. 11. Then, when thehandle 26 is turned into the open position (to the left), thetoggle mechanism 22 is collapsed to cause themovable contact element 8 to separate from thestationary contact 6 into the open position shown in Fig. 12. On the other hand, when an overcurrent flows through the circuit in the above described closed position shown in Fig.11, thebimetal 27 or themovable iron core 29 is actuated to release the engagement between thecradle 19 and the latch 31 (see Fig.13), so that thecradle 19 is rotated in the clockwise direction about thecradle shaft 32. Therefore, the connection point between thecradle 19 and theupper link 18 or the center of theshaft 21 moves beyond the line of action of thetoggle spring 24, then thetoggle link mechanism 22 is collapsed by the spring force of thetoggle spring 24, so that thecross bar 12 causes themovable contact elements 8 of all the poles together to separate from thestationary contact elements 6 in each pole, reaching to the tripped position shown in Fig. 13. - With the circuit interrupter as above discussed, in an unlikely event that the
movable contact 7 is welded in the closed position by an abnormal current and a non-separable state takes place, by moving thehandle 26 into the closed position as shown in Fig. 14, thetoggle spring 24 is expanded beyond the normal length allowing thehandle 26 to be moved and held in the open position, where the open position indicated by thehandle 26 does not correctly reflect the actual closed position of themovable contact 7. - Also Japanese Patent Publication No. 1-39176 discloses a conventional circuit interrupter in which the operating lever (corresponding to the handle arm) and the movable contact assembly engages each other when the contact elements are welded together so as not to permit the handle to move into the open position.
- In the above circuit interrupter, while it is possible to prevent the handle from moving into the open position when the movable contact is welded in the closed position by an abnormal current, there was a problem that the handle arm becomes large because the handle arm is arranged to directly engage the movable contact assembly.
- The document "US-A-5 304 765" discloses a circuit interrupter according to the preamble of
claim 1. - The invention is defined in
claim 1, and further modifications thereof are defined in the dependent claims. - According to the present disclosure, the circuit interrupter comprises, within an insulating housing composed of a base and a cover, a stationary contact, a movable contact separable from and opposing to said stationary contact, a toggle mechanism for driving said movable contact, a handle arm pivotally supported at a predetermined position relative to said toggle mechanisms, a trip device responsive t an overcurrent to actuate said toggle mechanism, and is characterized by a prevention portion engageable with said handle arm for preventing said handle to move into the open position. This allows the handle to be prevented from moved to the open position and the handle arm to be made relatively small-sized
- The prevention portion may be a cam portion disposed in a handle side link of the toggle link mechanism for engaging with the handle arm upon the welding of said movable contact and said stationary contact to prevent the handle from moving into the open position. This allows the handle to be prevented from moving in the direction of the open position and the handle arm to be made relatively small.
- The prevention portion which engages the handle arm of the handle side link of the toggle mechanism may be formed as an arc-shaped cam portion having its center on the pivot point of the handle side link. Since the pivot point of the handle side link and the center of the cam potion coincide, even when the handle side link pivots, the handle does not move in the direction toward the open position beyond the position in which it engages the cam portion, so that the welding of the contact elements can be clearly indicated.
- Also, the cam portion which engages the handle arm of the handle side link may comprise a second cam portion, which engages the handle arm in the first period of the handle moving process in which the handle is being moved toward the open position upon the welding of the movable contact element to the stationary contact element, and a first cam portion, which engages the handle arm in the last period of the handle moving process in which the handle is being moved toward the open position upon the welding of the movable contact element to the stationary contact element. Therefore, when the circuit interrupter is moving the handle from the closed position to the open position into counterclockwise direction, the bent engaging portion of the handle arm engages the second cam portion of the handle side link, thereby to cause the connection portion between the handle side link and the movable contact side link to quickly collapse, whereby the opening operation can be made more reliable. When the weld state between the contact elements is weak, the movable contact can be pulled up by the clockwise moment to separate the contact elements. The further movement of the handle arm causes engagement with the first cam portion, whereby the handle is prevented from further moving toward the open position.
- Also, the cam portion which engages the handle arm of the handle side link may be defined by a first cam portion of an arc having its center on the fulcrum of the handle side link and a second cam portion of an arc having its center at a position shifted from the fulcrum of the handle side link. Therefore, when the circuit interrupter is moving the handle from the closed position to the open position in the counterclockwise direction, the bent engaging portion of the handle arm engages the second cam portion of the handle side link, thereby to cause the connection portion between the handle side link and the movable contact side link to quickly collapse, whereby the opening operation can be made more reliable. When the weld state between the contact elements is weak, the movable contact can be pulled up by the clockwise moment to separate the contact elements. The further movement of the handle arm causes engagement with the first cam portion, whereby the handle is prevented from further moving toward the open position.
- A further disclosed embodiment of the circuit interrupter may comprise, within an insulating housing composed of a base and a cover, a stationary contact, a movable contact separable from and opposing to said stationary contact, a cross bar connecting one end of the movable contact together, a toggle mechanism for driving the movable contact, a handle arm pivotably supported at a predetermined position relative to said toggle mechanism, a handle moving in relation to the handle arm and a trip device responsive to an overcorrect to actuate said toggle mechanism, and may be characterized by a stopper for engaging between the cross bar and the handle arm upon the welding of the movable contact element of the movable contact to the stationary contact element of the stationary contact for preventing the handle to move into the open position. This allows the handle to be prevented from moved to the open position and made relatively small-sized, and the stopper to abut against the rigid cross bar which is not easily destroyed, so that the mechanism is strong.
- In this embodiment, a torsion spring for causing the stopper to always engage the handle arm may be provided. Thus, the handle arm is always biased in the clockwise direction to ensure the movement of the handle into the direction of the closed position, whereby position of the contact element of the circuit interrupter is ensured to precisely correspond to the state indicated by the handle.
- To enable a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:-
- Fig. 1 is a sectional side view of a circuit interrupter which is the first embodiment of the present invention, shown in the closed position;
- Fig. 2 is a sectional side view of the main portion showing the open position of the circuit interrupter shown in Fig. 1;
- Fig. 3 is a sectional side view of the main portion showing the tripped position of the circuit interrupter shown in Fig. 1;
- Fig. 4 is a sectional side view showing the position in which the handle is moved into the open position while the contact elements of the circuit interrupter shown in Fig. 1 is welded;
- Fig. 5 is a sectional side view of the circuit interrupter which is the second embodiment of the present invention;
- Fig. 6 is an enlarged sectional side view of the main portion of the circuit interrupter shown in Fig. 5 with its contact elements welded and with its handle moved in the open position;
- Fig. 7 is an enlarged sectional side view showing the position in which the toggle link mechanism is moved from the position shown in Fig. 6;
- Fig. 8 is a sectional side view of the circuit interrupter in the closed position which is the third embodiment of the present invention;
- Fig. 9 is a sectional side view of the circuit interrupter shown in Fig. 8 with its contact elements welded and with its handle moved in the open position;
- Fig. 10 is a sectional side view of the circuit interrupter of the fourth embodiment of the present invention;
- Fig. 11 is a sectional side view of a conventional circuit interrupter in the closed position;
- Fig. 12 is a sectional side view of the conventional circuit interrupter in the open position;
- Fig. 13 is a sectional side view of the conventional circuit interrupter in the tripped position; and
- Fig. 14 is a sectional side view of the conventional circuit interrupter in the position with the contact elements welded and the handle moved in the open position.
- Fig. 1 is a sectional side view of a circuit interrupter which is the first embodiment of the present disclosure showing the closed position with its one portion cut away to show the interior. Fig. 2 is a sectional side view of the main portion showing the open position of the circuit interrupter shown in Fig. 1, and Fig. 3 is a sectional side view of the main portion showing the tripped position of the circuit interrupter shown in Fig. 1. In the figures, 40 is a cover and 41 is a base, both made of a synthetic resin. 42 is a housing composed of the
cover 40 and thebase base 41 and having a stationary contact element 43a. 44 is a movable contact having amovable contact element 44a opposing to thestationary contact element 43a and is pivotally supported by apivot pin 45. 46 is a cross bar made of an insulating material connected to one end of the respectivemovable contacts 44 provided at each poles. 47 is a contact pressure spring disposed between themovable contact 44 and thecross bar 46 for always biasing themovable contact 44 toward the stationary contact element 43a. 48 is a flexible conductor with its one end connected to themovable contact 44 and the other end connected to a trip device (not shown). 49 is an arc extinguishing device for extinguishing an electric arc generated between thecontact elements magnetic plates 51 disposed within a pair of arc extinguishingside plates 50. - 52 is a movable contact side link (hereinafter simply referred to as a lower link) pivotally connected at one end to the
cross bar 46 by ashaft lower link 52 and at the other end to acradle 55 byshafts upper link 54. This prevention portion is defined by acam portion 54a of an arc section having a radius of R and a center at the center of theshaft 57 which is the fulcrum of theupper link 54. 58 is a toggle link mechanism composed of thelower link 52, theupper link 54 and theshaft 56, theshaft 56 being a knee portion. 59 is a handle arm having a bentengaging portion 59a and pivotally supported at oneend 59b as a pivot point on an unillustrated frame so as to be pivotable into a predetermined position relative to thetoggle link mechanism 58. 60 is a toggle spring connected at one end to thehandle arm 59 through aspring holding pin 61 and the other end to theshaft 56. 62 is a handle made of a synthetic resin and operable from the outside of thecover 40 cooperable with thehandle arm 59. 63 is a latch, which comprises alatch engaging portion 63a engaging thecradle 55 and arecess portion 63b in which alatch support shaft 64 is received, and engageable with the trip device (not shown) to be rotated about thelatch support shaft 64. 65 is a cradle support shaft pivotally supported by the unillustrated frame, and 66 is a stopper pin for theupper link 54 and themovable contact 44. - The operation will now be described. In Fig. 2, wherein the contact elements are in the open position, when the
handle 62 is turned to the closed position (to the right) in the state where thecradle 55 is latched by thelatch 63, thetoggle mechanism 58 is extended to cause themovable contact element 44a to contact with thestationary contact element 43a to bring the mechanism into the closed position shown in Fig. 1. Then, when thehandle 62 is turned toward the open position (to the left) and when the axis of thetoggle spring 60 moves beyond the line of action (dead point) passing through theshafts toggle link mechanism 58 collapses to pull up thelower link 52 to separate themovable contact element 44a from thestationary contact element 43a to bring the open position shown in Fig. 2. On the other hand, when an overcorrect flows through the circuit in the closed position shown in Fig. 1, the trip device (not shown) actuates to release the engagement between thecradle 55 and the latch 63 (see Fig. 3), thecradle 55 is rotated in the clockwise direction about thecradle support shaft 65. Therefore, the connection point between thecradle 55 and theupper link 54 or the point of theshaft 57 is moved beyond the line of action of thetoggle spring 60, so that thetoggle link mechanism 58 collapses due to the spring force of thetoggle spring 60, and themovable contact element 44a is separated from thestationary contact element 43a for each pole concurrently, thereby to become the tripped position shown in Fig. 3. - Fig. 4 illustrates the state in which a pulse-like massive current for example flows in the closed position so that a welding phenomenon took place between the
stationary contact element 43a and themovable contact element 44a while the engagement between thecradle 55 and thelatch 63 is not released, whereby themovable contact element 44a fails to separate from thestationary contact element 43a. In this position, thetoggle link mechanism 58 is held in the closed position, and when thehandle 62 is moved in the counterclockwise direction toward the open position in order to put the circuit interrupter in the open position as required for the inspection and maintenance as illustrated in Fig. 4, then thetoggle spring 60 is expanded to allow thehandle arm 59 to be rotated in the counterclockwise direction into the open position. However, while thehandle 62 is being moved in the counterclockwise direction, the bent engagingportion 59a of thehandle arm 59 abuts against and engages thecam portion 54a of theupper link 54 of thetoggle link mechanism 58 held in the closed position, thereby to preventing thehandle arm 59 from further moving toward the open position. - The arrangement may be such that the bent engaging
portion 59a of thehandle arm 59 abuts against and engages the lower link of thetoggle link mechanism 58 maintained at the closed position. Thus, since thetoggle mechanism 58 and the preventing portion or, more particularly, thecam 54a and the bent engagingportion 59a of thehandle arm 59 abut against and engage with each other, the handle arm can be made smaller as compared to that in the case where the movable contact assembly and the handle arm abut against and engage with each other. - Fig. 5 is a sectional side view of the circuit interrupter which is the second embodiment of the present disclosure with its one portion removed to show the interior thereof and illustrates the state in which the handle is moved toward the open position while the contact elements of the circuit interrupter are welded to each other. Fig. 6 is an enlarged sectional side view of the main portion of the circuit interrupter shown in Fig. 5 with its contact elements welded and with its handle moved in the open position. In the figures, 100 is an upper link, the configuration of which cam portion engaging the bent engaging
portion 59a of thehandle arm 59 comprises afirst cam portion 100a having a radius of curvature R1 with its center at the center C1 of theshaft 57 and asecond cam portion 100b having a radius of curvature R2 with its center at a position as the center C2 shifted by a distance L from the center C1 of theshaft 57 toward thelower link 52. For example, in the case of a circuit interrupter of 400 A (Amper) frame, the position of the center C2 is within the range of L = 2.5 ~ 3 mm and at a rotational angle θ = about 20° as measured in the clockwise direction relative to a dot-and-dash line passing through the center C1 and the center C3 of theshaft 56. - In the state shown in Fig. 5, when a pulse-like massive current for example flows in the closed position and a welding phenomenon took place between the
stationary contact element 43a and themovable contact element 44a while the engagement between thecradle 55 and thelatch 63 is not released, whereby themovable contact element 44a fails to separate from thestationary contact element 43a. In this position, when thehandle 62 is moved in the counterclockwise direction toward the open position in order to put the circuit interrupter in the open position as required for the inspection and maintenance, as illustrated in the detailed enlarged, sectional side view of the main portion of Fig. 6, then thetoggle spring 60 is expanded to allow thehandle arm 59 to be rotated in the counterclockwise direction into the open position. However, while the handle is being moved in the counterclockwise direction or at the first period in which thehandle 62 is being moved in the direction toward the open position, the bent engagingportion 59a of thehandle arm 59 abuts against and engages thecam portion 100b of theupper link 100. At this time, a pressing force F2 toward the center C2 acts at the contact point between thesecond cam portion 100b and the bent engagingportion 59a of thehandle arm 59. Since this force F2 is direction toward the center C2, theupper link 100 is subjected to a clockwise moment M = F2 x L about the fulcrum of the center C1 of theshaft 57, causing theshaft 56 connecting theupper link 100 and thelower link 52 to rotate in the direction of an arrow D. While this causes thelower link 52 to be lifted up in the direction of an arrow E as shown in Fig. 7 and themovable contact 44 is apt to separate from thestationary contact 43, the movable contact is permitted to move only by an amount corresponding to a gap G (see Fig. 6) and stay there because the contact elements are welded together. Since the portion of theshaft 56 bends, the bent engagingportion 59a of thehandle arm 59 is moved to the position where it is engaged by thefirst cam portion 100a and, at this time, or at the last period of the movement of thehandle 62 into the open position, the pressing force F1 acts at the contacting point between thefirst cam portion 100a and thehandle arm 59 is prevented from moving further toward the open position. - According to the second disclosed embodiment, during the process of the circuit interrupter shifting the
handle 62 from the closed position to the open position, the bent engagingportion 59a of thehandle arm 59 engages thesecond cam portion 100b of theupper link 100, to quickly collapse the connection portion between theupper link 100 and thelower link 52, so that the opening operation is more reliable. Also, when the weld is limited only in a small area, themovable contact 44 is lifted up by the clockwise moment M = F2 x L to separate the movable contact element. Also, since theupper link 100 rotates in the direction of collapse and thefirst cam portion 100a and the bent engagingportion 59a engage with each other, theupper link 100 rotates until theupper link 100 lifts up themovable contact 44, but thehandle 62 prevents theupper link 100 to move in the direction of closed beyond the point at which it abuts thecam portion 100a. - Fig. 8 is a sectional side view of the circuit interrupter in the closed position which is the third embodiment of the present disclosure, with one portion thereof removed to show the interior. In the figure, 1 ~ 66 are similar components to those of the above described first embodiment and their explanation is omitted. 70 is a stopper, which is pivotally supported by the
stopper support shaft 65 of thecradle 55 and having anarm portion 70a at one end and having astopper shaft 71 for engaging with the bent engagingportion 59a of thehandle arm 59 secured at the other end. - Fig. 9 illustrates the state in which a pulse-like massive current for example flows in the closed position so that a welding phenomenon took place between the
stationary contact element 43a and themovable contact element 44a while the engagement between thecradle 55 and thelatch 63 is not released, whereby themovable contact element 44a fails to separate from thestationary contact element 43a. In this position, when thehandle 62 is moved in the counterclockwise direction from the position shown in Fig. 8 toward the open position in order to put the circuit interrupter in the open position as required for the inspection and maintenance, then thetoggle spring 60 is expanded to allow thehandle arm 59 to be rotated in the counterclockwise direction into the open position (see Fig. 9). However, while thehandle 62 is being moved in the counterclockwise direction, the bent engagingportion 59a of thehandle arm 59 causes the rotation of theshaft 71 which is in abutment with the bent engagingportion 59a of thehandle arm 59 in the counterclockwise direction, and causes thearm portion 70a of thestopper 70 to rotate in the counterclockwise direction until it abuts against and engages aprojection portion 46a of the structurallyrigid cross bar 46, whereby thehandle arm 59 is prevented from being further moved toward the open position. The handle arm can be made smaller than that used in the conventional design in which the movable contact assembly and the handle arm abut against and engage with each other. - Fig. 10 is a sectional side view of a circuit interrupter. In the figure, 72 is a torsion spring, which is connected to the
stopper shaft 71 for causing thestopper shaft 71 to always abut against the bent engagingportion 59a of thehandle arm 59 thereby to always biasing thestopper 70 in the clockwise direction. - According to this embodiment, the biasing force of the
torsion spring 72 acting on thestopper 70 is a biasing force causing thehandle arm 59 and thehandle 62 to rotate in the clockwise direction. - The present invention has been made in order to solve the described problem with prior art devices, and advantageously provides an arrangement in which the handle cannot be moved to the open position when the movable contact element and the stationary contact element are welded together and in which the handle arm is relatively small.
- Also, another advantage is to provide an arrangement in which the handle cannot be moved to the open position when the movable contact element and the stationary contact element are welded together, the handle arm is relatively small and in which the mechanism is strong.
Claims (4)
- A circuit interrupter comprising, within an insulation housing (42) composed of a base (41) and a cover (40), a stationary contact (43), a movable contact (44) separable from and opposing said stationary contact (43), a toggle mechanism (58) for driving said movable contact (44), a handle arm (59) pivotably supported at a predetermined position relative to said toggle mechanism (58), a handle (62) interconnected to said handle arm (59) and a trip device responsive to an overcorrect to actuate said toggle mechanism (58), wherein said handle (62) is prevented from moving into the open position when a stationary contact element (43a) of said stationary contact (43) and a movable contact element (44a) of said movable contact (44) are welded to each other, wherein
said toggle mechanism (58) is provided with a prevention portion (54a) engageable with an engaging portion (59a) of said handle arm (59) for preventing said handle (62) from moving into the open position when said contacts (43, 44) are welded to each other, characterized in that: said prevention portion (54a) is configured to engage said engaging portion (59a) of said handle arm (59) at a position on the same side of said toggle link mechanism (58) as said stationary contact (43) and said moveable contact (44). - A circuit interrupter as claimed in claim 1, wherein said prevention portion (54a) is disposed on a handle side link (54) and comprises a first cam portion (100a) of an arc having its center on the fulcrum of said handle side link (54) and a second cam portion (100b) of an arc having its center at a position shifted from the fulcrum of said handle side link (54) toward a movable contact side link (52).
- A circuit interrupter as claimed in claim 2, wherein said second cam portion (100b) engages said handle arm (59) in a first period of the handle moving process in which said handle (62) is being moved toward the open position when said movable contact element (44a) is welded to said stationary contact element (43a), and wherein said first cam portion (100a) engages said handle arm (59) in the last period of said handle moving process.
- A circuit interrupter as claimed in claim 1, wherein said handle arm (59) is provided with an engaging portion (59a) bent from the rotational plane of said handle arm (59) to provide a raised surface on the same side of said handle arm (59) as said stationary contact element (43a) of said stationary contact (43) and said moveable contact element (44a) of said moveable contact (44).
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP1996/000670 WO1997035333A1 (en) | 1996-03-15 | 1996-03-15 | Circuit breaker |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0827173A1 EP0827173A1 (en) | 1998-03-04 |
EP0827173A4 EP0827173A4 (en) | 2000-05-17 |
EP0827173B1 true EP0827173B1 (en) | 2006-10-18 |
Family
ID=14153043
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP96906042A Expired - Lifetime EP0827173B1 (en) | 1996-03-15 | 1996-03-15 | Circuit breaker |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP0827173B1 (en) |
JP (1) | JP3814671B2 (en) |
KR (1) | KR100336946B1 (en) |
DE (1) | DE69636639T2 (en) |
TW (1) | TW353756B (en) |
WO (1) | WO1997035333A1 (en) |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3057155B2 (en) * | 1998-08-07 | 2000-06-26 | 寺崎電気産業株式会社 | Circuit breaker |
US6166344A (en) * | 1999-03-23 | 2000-12-26 | General Electric Company | Circuit breaker handle block |
ATE355604T1 (en) * | 2000-04-07 | 2006-03-15 | Hager Electro | SAFETY DEVICE FOR ELECTRICAL DEVICE OF CIRCUIT BREAKER TYPE |
KR100618607B1 (en) * | 2004-12-07 | 2006-09-08 | 엘에스산전 주식회사 | Mechanism structure of circuit breaker |
JP4552655B2 (en) * | 2005-01-12 | 2010-09-29 | 富士電機ホールディングス株式会社 | Circuit breaker |
KR200419048Y1 (en) * | 2006-03-17 | 2006-06-16 | 엘에스산전 주식회사 | A Mould Cased Circuit Breaker |
JP4857881B2 (en) * | 2006-04-14 | 2012-01-18 | 富士電機機器制御株式会社 | Circuit breaker |
JP5595827B2 (en) * | 2010-08-06 | 2014-09-24 | 河村電器産業株式会社 | Circuit breaker |
JP2016033892A (en) * | 2014-07-31 | 2016-03-10 | 河村電器産業株式会社 | Circuit breaker |
JP6395676B2 (en) * | 2015-07-31 | 2018-09-26 | 三菱電機株式会社 | Circuit breaker |
CN106206193B (en) * | 2016-08-29 | 2019-05-21 | 苏州未来电器股份有限公司 | The quick-release mechanism of breaker |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS58201221A (en) * | 1982-05-20 | 1983-11-24 | 寺崎電気産業株式会社 | Electric switch |
JPS58201223A (en) * | 1982-05-20 | 1983-11-24 | 寺崎電気産業株式会社 | Electric switch |
JPS58201222A (en) * | 1982-05-20 | 1983-11-24 | 寺崎電気産業株式会社 | Electric switch |
ZA898764B (en) * | 1988-12-08 | 1990-08-29 | Westinghouse Electric Corp | Electrical circuit breaker handle locking apparatus |
US5200724A (en) * | 1989-03-30 | 1993-04-06 | Westinghouse Electric Corp. | Electrical circuit breaker operating handle block |
US5142112A (en) * | 1990-04-03 | 1992-08-25 | Westinghouse Electric Corp. | Circuit breaker positive off interlock |
US5213206A (en) * | 1991-05-29 | 1993-05-25 | Westinghouse Electric Corp. | Circuit breaker with positive on/off interlock |
US5165532A (en) * | 1991-05-29 | 1992-11-24 | Westinghouse Electric Corp. | Circuit breaker with interlock for welding contacts |
DE9401785U1 (en) * | 1994-02-03 | 1995-07-20 | Klöckner-Moeller GmbH, 53115 Bonn | Key switch with a locking mechanism |
JPH07302534A (en) * | 1994-05-10 | 1995-11-14 | Fuji Electric Co Ltd | Opening and closing mechanism of circuit breaker |
-
1996
- 1996-03-15 JP JP53332697A patent/JP3814671B2/en not_active Expired - Lifetime
- 1996-03-15 DE DE69636639T patent/DE69636639T2/en not_active Expired - Fee Related
- 1996-03-15 EP EP96906042A patent/EP0827173B1/en not_active Expired - Lifetime
- 1996-03-15 KR KR1019970707836A patent/KR100336946B1/en not_active IP Right Cessation
- 1996-03-15 WO PCT/JP1996/000670 patent/WO1997035333A1/en active IP Right Grant
- 1996-06-10 TW TW085106938A patent/TW353756B/en active
Also Published As
Publication number | Publication date |
---|---|
JP3814671B2 (en) | 2006-08-30 |
EP0827173A1 (en) | 1998-03-04 |
DE69636639D1 (en) | 2006-11-30 |
KR19990008310A (en) | 1999-01-25 |
EP0827173A4 (en) | 2000-05-17 |
DE69636639T2 (en) | 2007-08-23 |
KR100336946B1 (en) | 2002-10-25 |
TW353756B (en) | 1999-03-01 |
WO1997035333A1 (en) | 1997-09-25 |
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