US3551627A

US3551627A - Circuit interrupter having a quick closing action

Info

Publication number: US3551627A
Application number: US745572A
Authority: US
Inventors: John A Bordak; Walter Kowalski
Original assignee: McGraw Edison Co
Current assignee: Cooper Industries LLC
Priority date: 1968-07-17
Filing date: 1968-07-17
Publication date: 1970-12-29
Anticipated expiration: 1987-12-29

Description

United States Patent [72] inventors John A. Bordak Milwaukee; Walter Kowalski, Oak Creek, Wis. [21 Appl. No. 745,572 [22] Filed July 17, 1968 [45] Patented Dec. 29, 1970 [73] Assignee McGraw-Edison Company Elgin, Ill. a corporation of Delaware [54] CIRCUIT INTERRUPTER HAVING A QUICK CLOSING ACTION 8 Claims, 5 Drawing Figs.

[52] U.S. Cl 200/153, 200/70, 200/150 [51] lnt.Cl H0lh5/10, HOlh 3/32 [50] Field olSearch ZOO/153.7, l53.8, 148.6, 150 (Cursory), 154, 78, 77.74, 70, [69(Cursory); 335/22, 46

[56] References Cited UNITED STATES PATENTS 2,521,194 9/1950 Van Ryan 335/22 Primary Examiner-Robert K. Schaefer Assistant Examiner-Robert A. Vanderhye Attorney-Richard C. Ruppin ABSTRACT: A circuit interrupter provided with movable contacts and an operating mechanism connected to the contacts and latched in position when the contacts are open. A manually operated movable drive member charges a pair of closing springs which apply force to the operating mechanism through a bias transfer member urging the operating mechanism to close the open contacts. The operating mechanism continues to be held latched until the drive member reaches a predetermined position during its movement where it releases the latched operating mechanism which then rapidly acts in response to the force of the charged closing springs to snap the contacts closed.

CIRCUIT INTERRUP'IER HAVING A QUICK CLOSING ACTION This invention relates to circuit interrupters and, in particular, to circuit interrupters utilizable as sectionalizing switches having a quick closing action. 7

Circuit interrupters are commonly used as sectionalizing switches in electrical distribution systems where it is desirable to interrupt and isolate a single section having an overcurrent condition from the rest of the system to which the sectionalizing switch is connected. Typically, the sectionalizing switch will sense the overcurrent condition and automatically open if the condition continues over a predetermined period of time. Also, opening of presently known sectionalizing switches may be effected manually if it is desired to isolate the section for other purposes such as repair work. Whether opening is automatically or manually effected, quick opening of the sectionalizing switches contacts is accomplished by the use of charged opening springs so that arcing at the contacts is minimized. I

Presently designed sectionalizers do not usually include a provision for quick closing of their contacts and, as a consequence, an arcingproblem occurs on closing. The closing speed of sectionalizer contacts is generally determined by the speed at which the operator manually pushes the closing handle. Particularly due to the possibility of closing the sectionalizing contacts when a fault current is present, it isdesirable to have the closing speed of the contacts uniform and of such force that arcing and damage .to the contacts on closing is minimized. v

An object of this invention is to provide a circuit interrupter or sectionalizing switch having contacts which may be closed manually at a speed and with a force independent of the speed and force of the manual operator.

Another object of this invention is to provide a sectionalizing switch having a manually operable contact operating means which closes the contacts of the switch with a snap-action substantially independent of the manual force applied to the contact operating means.

Another object of the invention is to provide a circuit interrupter or sectionalizing switch having a manually operable contact operating means which consistently closes the contacts of the switch at a uniform speed and with a uniform force. 1 I 1 A further object of the invention is to provide a sectionalizing switch having a manually operable contact operating means which closes the contacts of the-switch at a speed and force independent of the speed of the manual force applied to the operating means and which may also be utilized to automatically or manually perform a contact opening operation.

The objects of the invention are achieved by providing a circuit interrupter or sectionalizing switch contact operating means which maybe held in an open position corresponding to the open position of the circuit interrupter contacts and a releasable latch means engaging and holding the contact operating means in its open position. A pair of closing springs are secured to a member which bears against the latched operating means when the closingfsprings are charged. A movable drive member is attached to the closing springs and is moved by a manual operating handle to charge the closing springs so that a high closing force is applied to the latched operating means. Movement of the drive member also releases the latch after the closing springs have been charged so that the operating means is suddenly freed to snap the contacts closed in response to the discharging force of the closing springs.

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

FIG. I is an elevational view partly broken away to show the circuit interrupter or sectionalizer supported within an oil tilled tank;

the nature and objects of the invention,

FIG. 2 is a sectional view showing the upper part of the circuit interrupter;

FIG. 3 is a sectional view of the upper part of the circuit interrupter taken through section 3-3 in FIG. 2;

FIG. 4 is a sectional view, partially broken away. showing the upper part of the circuit interrupter; and

FIG. 5 is a sectional view similar to that of FIG. 2 in which the upper part of the circuit interrupter'is shown in a closed position.

Referring to the drawings, the circuit interrupter is shown to be mounted within a tank 2 partially filled with insulating oil 3 and having a flange 4 along its upper edge. The tank 2 is closed by a cover 6 which has a gasket 8 resting upon the flange 4 of the tank 2 when the cover 6 is secured in position on top of the tank 2. The cover 6 is tightly secured to the tank 2 by any suitable means, such as bolts I0. Insulating bushings l2 extend downwardly into the tank 2 and carry cable terminals 14 at their upper ends and terminals l6 at their lower ends.

The circuit interrupter is supported from the cover 6; The

insulating members 22 are attached to the cover and extend downwardly into the tank 2 to support the contact assembly 24 which is attached to the insulating members 22 by bolts 26. The contact assembly 24 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 conducting straps 36 connect the stationary contacts 30 and the terminals 16 on the ends of insulating bushings 12. As may be seen in FIG. 1 thecontact assembly 24 includes pins 38 on which the movable contacts 32 are pivotally mounted. The movable contacts 32 .also have slotted ends 40 pivotally pinned to the slide rod 34 at its lower end 42. A conducting member 46 connects the movable contacts 32 adjacent their ends 40. The slide rod 34 is slidably supported on the support member 28 at 44 so that sliding movement of slide rod 34 will pivot the movable contacts 32 about pins 38 to move themovable contactsj32 into and outof engagement with stationary contacts 30. Thus, the contacts '30 and 32 have a closed and open position when the slide rod 34 is respectively in a lower and upper position. A pair of opening springs 48 are connected at their upper ends to the cover 6 and at their lower ends to a transverse pin 50 mounted on the slide rod 34. The opening springs 48 are under tension so that the slide rod 34 and the

contacts

30 and 32 are respectively urged upward and to their open positions. A contact operating means 52 includes a toggle link mechanism 54 pivotally attached to the slide rod 34 by pin 50. a latch mechanism 56 supported on the toggle mechanism 54 and a bellcrank lever 58. The bellcrank lever 58 is mounted and freely rotatable on shaft 60 and has an arm 62 pinned to an end of toggle link mechanism 54 by pin 64. The contact operating means 52 has a position in which the arm 62 of bellcrank lever 58 is upward, as shown in FIGS. 2, 3 and 4. This position of the contact operating means 52 corresponds to the open position of the

contacts

30 and 32 and may also be considered as the open position of the contact operating means 52. The contact operating means 52 also has what may be considered a closed position corresponding to the closed position of the

contacts

30 and 32 and in which the toggle link mechanism 54 and the arm 62 of bellcrank 58 are positioned downwardly. A latch 66 is pivotally supported on the cover 6 and has a shoulder 68 which engages the flat face 70 of pin 64 when the arm 62 is downward to holdthe contact operating means 52 and the

contacts

30 and 32 in their closed positions against the upward opening force of opening springs 48. A spring 72 is positioned in engagement with latch 66 to positively hold the shoulder 68 in engagement with the face 70 of pin 64.

As shown in FIGS. 2, 4 and 5, the toggle link mechanism 54 includes an upper link arm 74 and alower double-arm link 76 pivotally connected by pin 78. The latch mechanism 56 is supso that it will not collapse to allow release latch 66 and the opening of the

contacts

30 and 32 by springs 48. When an overcurrent condition occurs in the circuit in which the interrupter is connected, an overcurrent means (not shown) moves into engagement with the latch mechanism 56 to unlatch and collapse the toggle link mechanism 54. The contact operating means 52 is then free to move to its open position and open the

contacts

30 and 32 by the force of spring' 48. For a more complete description of the latch mechanism 56 and an overcurrent means usable in the illustrated circuit interrupter, reference is made to US. Pat. No. 2,521,194, issued Sept. 5, 1950, and assigned to the assignee of the instant invention.

When the coiitact operating means 52 is in its open position, the arm 82 of the bellcrank lever 58 is held downward by engagement of the holding or latch member84 with the pin 86 mounted on the end of lever arm 82. To insure that thebellcrank 58 is rotated sufficiently far enough for the pin 86 to be engaged by holding member 84, a spring 87 urging the bellcrank 58 in a counterclockwise direction is connected between the bellcrank 58 and the cover 6. The holding .member 84 is pivotally mounted on pin 88 and has a release arm 90 and a latching arm 92. A spring 85 is supported on pin 88 and urges holding member 84 toward the bellcrank 58 to insure engagement of the shoulder 94 with the pin 86 so that rotatably mounted on the cover 6 and has an end 98 extending positions and up when the contact operating means 52'and contacts and 32 are in their closed positions so that'the 1 position of the handle indicates the closed or open condition of the contacts. A bias transfer arm 102 is mounted on the shaft 60 adjacent the bellcrank 58 and rotates freely on the shaft 60, The arm 102 has a projecting finger 104 maintained in engagement with the arm 82 of bellcrank 58 by the spring 106 connected between the end 108 of arm 102 and the pin 86 on bellcrank 58. A pair of closing springs 110 are connected between the U-shaped drive member 96 and the pins 112 extending from the end 108 of arm 102.

As previously discussed, when the contacts 30 and '32 and thecontact-operating means "52 are in their open positions, the arm 82 of bellcrank 58 is positioned downwardly and the entire contact-operating means 52 is latched in its open position by the holding member 84. In order to'perform a closing operation, the operatinghandle 100 is turned to rotate the shaft 60 in a clockwise direction. Rotating of the shaft 60 in the clockwise direction will also rotate the drive member 96 to move its end 114 away from the end 108 of transfer arm 102 and stretch or charge the closing springs 110. The closing springs 110 will be charged because the bellcrank 58 is held in position by holding member 84 so that arm 102 engaging bell- .crank f 8 will not move. As the springs 110 are charged, their I biasing force on arm 102 will be transferred to bellcrank 58 greatly increased. As the drive means 96 goes past its position shown in phantom lines in FIG. 2, its edge 116 engages arm Y .of holding means 84 and rotates holding means 84 clockwise to release the pin 86 and bellcrank 58. The closing springs are-thereby allowed to rapidly contract and discharge to snap arm 102 and bellcrank 58 clockwise and rapidly move contact-operating means 52 and

contacts

30 and 32 to their 32 may be closed at a high speed so that damage to the contacts due to arcing while closing is minimized, particularly where contacts are closed during an overcu'rrent condition.

When the contact-operating means 52 moves to its, closed position, the arm 62 of bellcrank 58 moves downward so that the pin 64 is engaged and held by latch 66. The arm 82 of bellcrank 58 is in an upwardposition whenthe contact-operating means 52 is in its closedposition. Since the bias transfer arm 102 is connected to the bellcrank 58 by spring 106. the rii t to" 102 15 also in a SOmWh8tJlS8d posit on sothat the drive arm 102 has a raised rib portion 126 and its end 108 has a rounded foot portion 118 for engaging and pivoting the latch 66 in a counterclockwise direction. The drive member 96 has an extending finger 120 which engages the rib 126 on arm 102 when the drive member 96 is rotated counterclockwise. Thus, rotation of the operating handle 100 in z t-counterclockwise direction moves the extending finger 120 into engagement with the rib 126 so' that the foot 118 of arm 102 pushes the latch 66 away from the pin 64 and allows the contact-operat-l ing means 52 to move to its open position due to force from the opening springs 48. A dependingstop member 122 is provided on the cover 6 to engage the stop finger 124 extending from arm 102 and prevent the arm 102 fromjammingagainst the latch 66. i 1'1 4 Although a preferred embodiment of the invention has been illustrated and described, the disclosure is notto be interpreted as limiting, for the invention may be variously embodied and is to be construed in accord with the claims which follow:

We claim:

1. In a circuit interrupter including contactormeans having an open and closed position, the combination comprising:

operating means movable-between first and second positions respectively corresponding to the openand-closed positions of the contactor means and being connected to said contactor means for'rnoving'the contactor means betweenits open and closed positions; releasable holding means engaging the operating means when in its first position to hold'the operating means and the contactor means in their respective first andxopen positions; a i

resilient means spaced from said operating means'and being chargeable to provide a force for biasing the operating means and contactor means to their respective second and closed positions against the holding force of the holding means and a force for moving thefoperating means and contactor means to their respective second and closed positions upon release of the holding means;

bias transfer means connected to the resilient means and engaging the operating means when the resilient means is charged to apply the biasing and moving force of the resilient means to the operating means; and drive means movable independently of the bias transfer means, said drive means being connected to the resilient means and being movable to charge the resilient means and release the holding means'whereby said biasing and moving forces are provided to the bias transfer means.

2. The combination according to claim 1 further comprising: v, 1

releasable latch means engaging the operating means when in its second position to hold the operating means and the contactor means in their respective second and closed positions; i second resilient means secured to said operating means and charged by the operating means when it moves to its second position for biasing the operating means and contact means toward their respective first and open positions against the holding force of the latching means; said bias transfer means being normally in engagement with the operating means and being movable out of engagement with the operating means when the operating means is held in its second position by the latch means and into releasable engagement with the latch means whereby the operating means is freed to move to its first position and the charged second resilient means discharges to move the operating means and the contact means to their respective first and open positions; and

said drive means is movable toward athird'position to move the bias transfer means into releasable engagement with the latch means.

3. The combination according to claim 2 wherein said drive means and bias transfer means are mounted on a common axis and pivotally move about said axis.

4. The combination according to claim 1 wherein said bias transfer means is in a stationary position engaging the operating means and said drive means is simultaneously movable toward the holding means.

5. In a circuit interrupter including contactor means having an open and closed position, operating means movable between first and second positions respectively corresponding to the open and closed positions of the contactor means and being connected to said contactor means for moving the contactor means between its open and closed positions, the combination comprising:

a first latch holding the operating means in its first position; a first spring having a charged condition, said spring biasing the operating means and contactor means to their respective second and closed positions; a drive member connected to the first spring and being movable from a first position toward the first latch to charge the spring, said drive member having a second position in releasable engagement with the latch whereby said operating means is released and the spring discharges to move the operating means and contactor means to their respective second and closed positions; and

a bias transfer lever positionable independently of said drive member, said bias transfer lever being connected to the spring and maintained by the spring in compressive engagement with the operating means in opposition to said latch when said spring is in its charged condition whereby the biasing force of the spring is transferred to the operatmg means.

6. The combination accordingto claim 5. further comprisa second latch holding the operating means when the latter is in its second position;

' a second spring connected to said operating means and having a charged condition, said second spring biasing the operating means and contactor: means toward their respective first and open positions against the holding force of the second latch; and

said bias transfer lever being movable into releasable engagement with said second latch by the drive member and said first spring whereby said second spring biases the contactor means to its open position.

7. The combination according to claim 5 wherein said drive member and bias transfer lever are mounted on a common