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Publication numberUS3593229 A
Publication typeGrant
Publication dateJul 13, 1971
Filing dateDec 5, 1969
Priority dateDec 5, 1969
Publication numberUS 3593229 A, US 3593229A, US-A-3593229, US3593229 A, US3593229A
InventorsDate Kazuo Henry
Original AssigneeMc Graw Edison Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Resetting means for sectionalizing switch
US 3593229 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

United States Patent I2 NH UN I RESET'I'ING MEANS FOR SECTIONALIZING SW ITCH l4 Claims, 3 Drawing Fig.

lnt.Cl. .v. ...H0ll|75/04 FieldoiSeor-ch i 4 A 335/3216,

.............. g,'29. 30. an. 33, 34

[56] Relerences Cited UNITED STATES PATENTS 2.828.383 3ll9$8 Uhrig 335/29 3,344,372 9/l967 Heilmln l. 335/28 Primary Examiner-Harold Broorne Attorney-Richard C. Ruppin ABSTRACT: A quick reset means is disclosed for s sectionalizing switch having a trip device which is advanced to a tripping position to cause the switch operating means to move to an open position snd open the switch contacts. The reset means includes resilient means held loaded by the switch operating means when the latter is in its closed position. The reset means is movable into impacting engagement with the trip mechanism due to the force supplied by the resilient means. Thus, when the operating means is tripped and moved to its open position, the reset means is released and impacts the trip mechanism to quickly reset the trip mechanism.

RESE'ITING MEANS FOR SECTIONALIZING SWITCH This invention relates to circuit interrupters and, in particular, to a reset mechanism for a sectionalizing switch.

Automatic circuit interrupters are commonly used as sectionalizing switches in electrical distribution systems where it is desirable to interrupt and isolate a single section of the system having a permanent fault condition. Typically, the sectionalizing switch is connected in the branch of a system in series with a backup device such as an automatically reclosing circuit breaker. The sectionalizing switch is coordinated with the reclosing circuit breaker so that the latter will open the system several times before the sectionalizing switch locks open during an interval when the backup device is opened. To effect such coordination. the sectionalizing switch will usually have a tripping mechanism which is stepped to a tripping posi' tion during the opening and reclosing operation of the recloser. After a predetermined number of reclosing and opening operations, the trip mechanism of the sectionalizing switch will cause the switch to open during an open circuit interval.

A problem that arises when the sectionalizing switch is manually reclosed immediately after tripping and locking open is that the tripping mechanism has not had time to reset to its normal position so that the operation of the sectionalizing switch will again be coordinated with the reclosing circuit breaker. The result is that the sectionalizing switch may immediately open because the tripping mechanism is still in its trip positic... Thus, the sectionalizing switch will attempt to interrupt fault current far in excess of iis interrupting rating before the reclosing circuit breaker has an opportunity to open circuit the system.

An object of this invention is to provide a circuit interrupter having a trip mechanism and a trip mechanism reset means which will quickly reset the trip mechanism immediately after each opening and lockout operation of the circuit interrupter.

Another object of this invention is to provide a resetting means for the trip mechanism of a circuit interrupter which will accurately reset the tripping mechanism to a predetermined position.

The objects of the invention are achieved by providing a reset mechanism for the tripping means of a circuit interrupter or sectionalizing switch which is actuated by the contact operating means of the circuit interrupter. The reset mechanism is moved to a high impact position by the contact operating means when the latter is moved to its closed position. The reset mechanism is held in the high impact position by the contact operating means until the operating means is tripped by the tripping means whereupon the reset mechanism is released to impact the tripping means and quickly return the tripping means to its normal position in preparation for another tripping operation.

Other objects and advantages of the invention will in part be obvious and will in part appear hereinafter. For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:

FIG. I is an elevational view, partially in section. showing a circuit interrupter having its contact operating means in a closed position and the reset means of the invention in a fully biased position;

FIG. 2 is an elevational view similar to FIG. 1, partially in section and with parts removed, showing the tripping mechanism at its normal or reset position and the reset mechanism in a biased position; and

FIG. 3 is an' elevational view showing the tripping mechanism and the reset mechanism of the invention subsequent to a tripping and reset operation.

Referring to the drawings, the circuit interrupter is shown to be mounted within a tank 2 partially filled with insulating oil 4. The tank 2 is closed by a cover 6 secured to the tank 2 by suitable means such as bolts 10. Insulating bushings 12, only one of which is shown, extend downwardly into the tank 2 and carry cable terminals I4 at their upper ends and terminals 16 at their lower ends.

With reference to FIG. 1, a contact assembly 24 is provided which includes the insulating support member 28, the stationary contacts 30 mounted on support member 28, the movable contacts 32 and the slide rod 34. The insulating members 22 are attached to the cover 6 and extend downwardly into the tank 2 to support the contact assembly 24. The slide rod 34 is slidably supported on the support member 28 and slides to a downward position in which the stationary contacts 30 and movable contacts 32 are engaged, shown in FIG. I, and to an upward position in which said contacts 30 and 32 are disengaged.

A portion of a contact operating means 36 is shown in its closed position in FIGS. 1 and 2 and in its open position in FIG. 3. The closed position of the contact operating means 36 corresponds to the engaged position of the stationary contacts 30 and movable contacts 32 and the open position of the contact operating means 36 corresponds to the disengaged position of the contacts 30 and 32. As shown in FIG. 2, the contact operating means 36 includes a toggle link mechanism 3! pivotally attached to the slide rod 34 by pin 50, a latch mechanism 40 supported on the toggle mechanism 38 and opening spring means 42. The spring means 42 is connected between the pin 50 and the inside of cover 6 by means not shown. The toggle link mechanism 38 includes an upper link arm 44 and a lower double-arm link 46 pivotally connected by the pin 48. The latch mechanism 40 is supported between the arms of the double-arm link 46 and latches the toggle mechanism 38 so that it will not collapse to allow movement upward of the slide rod 34 and the disengagement of contacts 30 and 32 by the opening spring means 42. Other components of the contact operating means 36 are not shown inasmuch as they form no part of the present invention. It is sufficient to say for the present purposes that the parts of the contact operating means 36 which are not shown operate generally to cause the engagement and disengagement of the contacts 30 and 32. Contact operating means of a type suitable for use in the present invention are shown and described in detail in copending application Ser. No. 745,572, filed July 17, 1968, and assigned to the assignee of the present invention.

FIGS. 1 and 2 show a trip mechanism 70 mounted on the support member 28 and an overcurrent sensing means designated generally by the numeral 50. The trip mechanism 70 includes the trip piston 72. The overcurrent sensing means 50 is of a type well known in the art and includes a solenoid coil 5l electrically coupled to the line in which the circuit interrupter is connected through the conducting strap 58 connected between solenoid terminal 56 and terminal I6 and the conducting cable 60 connected between solenoid terminal 62 and stationary contact 30. A solenoid plunger 52 is biased by a spring means 55 in an upward direction within the sleeve 54 (see FIGS. 2 and 3). The plunger 52 is pulled downward and held against the biasing force of the spring means 55 by the solenoid coil 52 when it is energized and a predetermined current value flows through it. Upon deenergization of the solenoid coil 51, the plunger 52 is released and the spring means 55 urges it upwardly. The overcurrent sensing means 50 includes valve means (not shown) for pumping oil 4 from the tank 2 through an opening (not shown) in plunger 52 to the top 53 of the plunger 52. A predetermined volume of oil 4 is displaced to the top 53 of the plunger 52 each time the plunger 52 is pulled downward by the solenoid coil 51. Upon deenergization of the solenoid coil 51, the spring means 55 moves the plunger 52 upward to force oil 4 through the impulse valve 64 and into the sleeve 54 below trip piston 72. The trip piston 72 is thereby moved upward within the sleeve 54 a distance determined by the volume of oil forced through the impulse. valve 64. The impulse valve 64 is of a well known type which permits flow of liquid through it while minimizing pressure resulting from the flow of the liquid. When the circuit breaker is utilized as a sectionalizing switch connected on the load side of a reclosing circuit breaker. the solenoid coil 5] will be deenergized and energized each time the recloser performs an opening and closing operation. Thus, the trip piston 72 will be moved upward in a series of steps each corresponding to an opening and closing operation of the reclosing circuit breaker. As described in detail hereinafter, when the trip piston 72 is stepped to a trip position, the trip mechanism 70 will cause the sectionalizing switch to open.

For a more complete description of an overcurrent sensing means usable in the illustrated circuit interrupter, reference is made to US. Pat. No. 2,52l,l94, issued Sept. 5, 1960, and assigned to the assignee of the instant invention.

The trip mechanism 70 includes the trip piston 72 and the trip lever 74 pivotally mounted on the support member 28. The trip lever 74 has an arm 76 including a bifurcated end 78 extending to a position above the sleeve 54. A finger 80 is adjustably mounted between the bifurcations of the end 78 and extends into the sleeve 54. As shown in FIGS. 2 and 3, the finger 80 has a plurality of spaced openings 82 and is mounted on the end 78 by means such as a cotter pin 84 extending through one of the openings 82. The cotter pin 84 also holds a spacer 86 which extends horizontally away from the end 78. A trip reset mechanism 90 is provided and includes a lever arm 92 pivotally mounted on the support member 28 between the ends 96 of the arm 92. A spring 94 is connected between the end 96 of arm 92 and the support member 28 and biases the arm 92 downward toward engagement with spacer 86. The end 98 of the arm 92 is engaged by a spacer I held on link 46 by pin 50 when the contact operating means 36 is in its closed position. As shown in FIG. 2, the arm 92 is pivoted to raise the end 96 of arm 92 above spacer 86 when the contact operating means 36 is in its closed position. Raising the end 96 of arm 92 also loads the spring 94. When the contact operating means 36 is in its open position, as shown in FIG. 3, the end 96 of arm 92 is held in a downward position by spring 94.

The operation of the trip mechanism 70 and reset mechanism 90 in combination with the contact operating means 36 is as follows. In FIG. 2, the contact operating means 36 is shown in its closed position during normal load conditions in the section in which the sectionalizing switch is connected. During normal current conditions. the contacts 30 and 32 will be closed, however, the current flowing through the solenoid coil will not be sufficient to pull the plunger 52 downward. The plunger 52 is thus in its upward position adjacent to the bottom of impulse valve 64 during normal operating conditions of the sectionalizing switch. During normal closed conditions, the trip lever 74 is in its reset position as shown in FIG. 2. Also, the trip reset mechanism 90 is held in its loaded condition by the contact operating means 36.

When an overcurrent having a predetermined value occurs, the solenoid coil 5] will pull the plunger 52 downward to cause oil 4 to be displaced to the top 53 of the plunger 52. Shortly after the overcurrent condition occurs, the aforementioned reclosing circuit breaker will interrupt the system so that the solenoid coil 5] is deenergized and the plunger 52 is biased upward by the spring means 55 to force the oil 4 through the impulse valve 64 and move the trip piston 72 upward a distance determined by the amount of oil forced through the valve 64. This is the first stepped movement of the trip piston 72 and does not affect the trip lever 74 unless the finger 80 is set to a low position on the lever 74. As shown in FIG. I, the finger 80 is secured to the lever 74 at a middle one of the holes 82. In this position, the trip piston 72 does not engage the finger 80 to move the trip lever 74 to a trip position on the first step of the trip piston 72. After a predetermined time period, the reclosing circuit breaker will close and again energize the system. If the overcurrent condition continues on the line in which the sectionalizing switch is connected. solenoid coil 51 will again pull the plunger 52 downward to displace oil 4 to the top 53 of plunger 52 and the reclosing circuit breaker will open to deenergize the solenoid coil 51. The spring means 55 then biases the plunger 52 upward to force oil through the valve 64 and step the trip piston 72 upward a second time. Depending on the position at which the finger is set, the trip piston 72 may engage the finger 80 and move it upward to pivot the trip lever 74 to a tripping position against the latch mechanism 40. It the finger 80 is set at the middle one of the holes 82, the sectionalizing switch will be tripped open upon movement of the trip piston 72 upward a second time. However, if the finger 80 is set at the highest one of the holes 82, the trip lever 74 will not be moved far enough to trip the latch mechanism 40. In the latter case, upon the reclosing of the circuit breaker, if an overcurrent condition continues on the line in which the sectionalizing switch is connected, the circuit breaker will open and the trip piston 72 will be advanced another step upward. At this third step of the trip piston '72, the trip mechanism 70 is moved to the trip position in which the latch mechanism 40 is released. The toggle link mechanism 38 is thereby collapsed to allow the opening spring means 42 to move the contact operating means 36 to its open position as shown in FIG. 3. The reset mechanism is thereby released and the lever arm 92 snaps downward to impact the spacer 86 under the force applied by the spring 94. This provides a quick reset action for the trip piston 72 and the trip lever 74 so that the entire trip mechanism 70 is reset and thereby prepared to step through its switch opening operation in coordination with the reclosing circuit breaker.

A quick reset of the trip mechanism 70 is particularly important where the contact operating means 36 is manually moved to its closed position a short time following an opening operation and the contacts 30 and 32 are thereby closed. Under these conditions, the trip lever 74 will still be close to its trip position and, if a fault condition exists, the contact operating means 36 will be immediately tripped to open the contacts 30 and 32 before the reclosing circuit breaker has had an opportunity to deenergize the system. Since the contacts 30 and 32 of the sectionalizing switch are not rated for fault interrupting duty, interrupting of fault current will be damaging to them. Further, when the contact operating means 36 is moved towards its closed position while the trip lever 74 is close to its trip position, the contact operating means 36 will be tripped open before the opening spring means 42 has been fully charged for an opening operation. This will result in a slower opening operation to the further damage of the switch contacts 30 and 32. Another advantage of the quick reset means provided by the invention is that a positive force is provided to overcome friction or foreign matter preventing reset movement of the trip piston 72.

Although a preferred embodiment of the invention has been illustrated and described, the disclosure is not to be limiting, for the invention may be variously embodied and is to be construed in accord with the claims which follow.

lclaim:

1. In a circuit breaker including contact operating means having an open and a closed position, the combination comprising trip means having a first and a second position and being movable from the first position to the second position for releasing the contact operating means from its closed position and trip reset means responsive to the contact operating means upon release from its closed position and spaced apart from the contact operating means when the latter is in its open position for movably resetting the trip means from its second position to its first position, said contact operating means holding the trip reset means out of resetting movement when the contact operating means is in its closed position.

2. The combination according to claim I wherein said trip reset means is engaged and disengaged with the contact operating means when the latter is respectively in its closed and open positions.

3. The combination according to claim 2 wherein said trip reset means includes resilient means and said contact operating means moves from disengagement to engagement with the trip reset means to load the resilient means when the contact operating means moves from its open to its closed positions.

4. The combination according to claim 1 wherein said trip reset means moves into impacting engagement with the trip means to move the latter from its second position to its first position when the contact operating means is released from its closed position.

5. The combination according to claim 4 wherein said trip reset means comprises a pivotally mounted lever arm having an end connected to said resilient means and an end engaged by the contact operating means when the latter is in its closed position, said arm pivoting into impacting engagement with the trip means when the contact operating means is released from its closed position.

6. In a circuit breaker including contact operating means having a closed position. the combination comprising trip means having a trip piston having intermediate and trip positions and being movable from the intermediate to the trip position for releasing the contact operating means from its closed position and trip reset means for resetting the trip piston to its intermediate position from its trip position, said contact operating means holding the trip reset means out of resetting actuation when the contact operating means is in its closed position.

7. The combination according to claim 6 wherein said trip piston has a normal position and is free relative to said trip reset means to move to said normal position after being reset by said trip reset means.

8. The combination according to claim 6 wherein said trip means includes a trip lever engaging and releasing the contact operating means from its closed position when the trip piston is in its trip position, said trip lever being moved into engagement with the contact operating means by the trip piston.

9. The combination according to claim 6 wherein said trip means includes a cylinder, said trip piston being mounted within the cylinder, and means for pumping a fluid into said cylinder on one side of said piston to move said piston from its normal to its trip position.

It). In a circuit interrupter connected to a line conducting current and including stationary contact means, movable contact means movable into engagement with the stationary contact means and means for disengaging said movable and stationary contact means. the combination comprising moving means supporting said movable contact means for moving said movable and stationary contact means toward engagement with each other and holding said contact means in said engagement. said moving means engaging said disengaging means and including releasable means for preventing operation of said disengaging means, tripping means responsive to current impulses in said line equal to or greater than a predetermined magnitude for counting said current impulses. said tripping means having a first position and a second position and being movable from the first position to the second position for releasing said releasable means alter a predetermined number of current impulses to allow operation of said disengaging means. and means responsive to said moving means for immediately resetting said tripping means to said first position after releasing of said releasable means.

1]. The combination according to claim I0 wherein said resetting means is responsive to said moving means only when the latter is moving the movable and stationary contact means toward engagement with each other and holding said contact means in said engagement.

12. The combination according to claim ll wherein said moving means is movable into and out of engagement with the resetting means.

IS. The combination according to claim l2 wherein said resetting means and moving means are in engagement only when the latter is moving the movable and stationary contact means toward each other and holding said contact means in engagement.

I4. The combination according to claim 10 wherein said tripping means has a normal position and is movable between the normal position and said first position. said tripping means being free relative to said releasable means to return to said normal position after being reset to said first position.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2828383 *Dec 16, 1953Mar 25, 1958Westinghouse Electric CorpLine sectionalizers
US3344372 *Oct 21, 1965Sep 26, 1967Heinemann Electric CoTime delay tube reset device
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7154061Jul 21, 2004Dec 26, 2006Abb Inc.Interrupter assembly for a circuit breaker
US20060017531 *Jul 21, 2004Jan 26, 2006Eley Edgar RInterrupter assembly for a circuit breaker
Classifications
U.S. Classification335/29
International ClassificationH01H75/04, H01H75/00
Cooperative ClassificationH01H75/04
European ClassificationH01H75/04
Legal Events
DateCodeEventDescription
Apr 25, 1986ASAssignment
Owner name: COOPER INDUSTRIES, INC., 1001 FANNIN, HOUSTON, TX
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:MCGRAW-EDISON COMPANY, A CORP OF DE;REEL/FRAME:004600/0418
Effective date: 19860401
Owner name: COOPER INDUSTRIES, INC., A CORP OF OH,TEXAS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MCGRAW-EDISON COMPANY, A CORP OF DE;REEL/FRAME:4600/418
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MCGRAW-EDISON COMPANY, A CORP OF DE;REEL/FRAME:004600/0418