US2898421A

US2898421A - Repeating circuit interrupter

Info

Publication number: US2898421A
Application number: US752119A
Authority: US
Inventors: Date Kazuo Henry
Original assignee: McGraw Edison Co
Current assignee: McGraw Edison Co
Priority date: 1958-07-30
Filing date: 1958-07-30
Publication date: 1959-08-04
Anticipated expiration: 1976-08-04

Description

Aug. 4, 1959 K. H. DATE REPEATING CIRCUIT INTERRUPTER 4 Sheets-She et 1 Filed July 30, 1958 INVENTOR.

744200 Henry Date fitter?? Aug. 4, 1959 I K. H. DATE REPEATING CIRCUIT INTERRUPTER 4 Sheets-Sheet 2 Filed July 50, 1958 Aug. 4, 1959 K. H. DATE REPEATING CIRCUIT INTERRUPTER 4 Sheets-Sheet 3 Filed July 30, 1958 |Ilii :1.

INVENTOR.

a U0 iz eny Date ,1 [4

1 K. H. DATE v 2,898,421

REPEATING CIRCUIT INTERRUPTER I I 4 Sheets-Sheet 4 Filed July 30, 1958 INVENTOR. Kazuo Henry Date afttornqy United States Patent REPEATIN G CIRCUIT INTERRUPTER Kazuo Henry Date, South Milwaukee, Wis., assignor to McGraw-Edison Company, Milwaukee, Wis., a corporation of Delaware Application July 30, 1958, Serial No. 752,119

9 Claims. (Cl. 200-89) This invention relates to repeating circuit interrupters. A circuit interrupter to which the present invention most aptly applies is in the class commonly known as reclosers and the apparatus under consideration will be designated a recloser in this application. n A polyphase recloser may be characterized as a circuit protective device having fault sensing devices interrupting switches, operation counting mechanisms, reclosing means and lockout mechanism principally contained in a single tank or in such close association as to be considered a single entity. More specifically, it is usually pro vided with series connected overload relays that respond to overload currents, flowing in any direction to one or more phases, by instantaneously tripping the interrupting switches a predetermined number of times and a reclosing solenoid that responds to a source of voltage to close the interrupting switches simultaneously after they have reached their fully open position. The energizing of the reclosing solenoid is accomplished by secondary contact means adapted and arranged to place the solenoid coil in circuit with a source of electrical energy, usually between phases, when the interrupting contacts have reached their fully open position, and to open circuit the solenoid coil when the solenoid armature has moved a sufiicient distance to reclose the interrupting contacts. The lockout mechanism operates to hold the secondary contact means in the open position after a predetermined number of operations of the recloser, thereby preventing the device from reclosing.

The polyphase circuit interrupter chosen for illustrating the invention is set forth in great detail in US. Patent 2,804,521 to Van Ryan et al. assigned to the same assignee as this invention.

Under certain conditions of operation such as single phasing, the phase-to-phase voltage is not sufficient to move the solenoid armature the distance required to reclose the main interrupting contacts or to open the solenoid or secondary contact means. The solenoid coil, consequently, remains energized for an inordinate length of time thereby causing it to become unduly heated which may result in its becoming seriously damaged. Also, there is no external indication of this condition because only lockout normally produces such a signal.

It is an object of the invention to provide undervoltage protection for the electromotive reclosing means of a repeating circuit interrupter.

It is another object of the invention to provide means for open circuiting the electromotive reclosing means of a repeating circuit interrupter when the voltage applied to said electromotive means is insufiicient to result in closing of said circuit interrupter.

A primary object of the invention is to provide a repeating circuit interrupter with electromotive reclosing means and control means therefor which are so arranged that when the voltage supplied said electromotive means is insufficient to cause closure of said circuit interrupter, the electromotive means will be open circuited so as to prevent continual heating thereof.

Patented Aug. 4, 1959 and operate said lockout means to permanently open said circuit interrupter.

A still further object of the invention is to provide a repeating circuit interrupter having electromotive reclosing means and control means for energizing said electromotive means upon the opening of said circuit interrupter and for de-energizing said electromotive means upon the closing of said circuit interrupter and wherein said electromotive means will be tie-energized when the operating voltage is insuflicient to result in closure of said circuit interrupter.

Other objects and advantages of the present invention will become apparent from the following detailed description taken in view of the drawings in which:

Fig. 1 schematically illustrates the principal components of a polypase recloser embodying the present in vention;

Figs. 2-5 schematically illustrate the operation of the present invention;

Fig. 6 shows a partial plan view of a recloser showing a preferred embodiment of the present invention; Fig. 7 is a top view of the preferred embodiment of the invention shown in Fig. 6; 1 Fig. 8 is a partial sectional view of a alongline 8-8 of Fig. 7;

Fig. 9 is a perspective view of. a portion of a recloser embodying the present invention; and

Fig. 10 is a partial sectional view of a recloser showing an alternate embodiment of the present invention.

, Before discussing the improvements comprising the in stant .invention in detail, conventional fault protective features of a polyphase recloser will be outlined with reference to Fig. 1. It will be appreciated that all components shown in this figure may be self-contained or housed in a metal tank wherein at least the portion enclosing theinterrupting switches is partially or wholly occupied by dielectric fluid. The metal container for the apparatus is not shown, but it normally supports a set of incoming porcelain bushings 1 and outgoing porcelain bushings 2 which are schematically illustrated. In each phase, between incoming source terminals l1 and outgoing load terminals 2 there is a series circuit-consisting of an overload responsive relay 3, heavy load wires 4 anda main interrupting switch 5. Only one oft-he overload relays 3 is shown, but it will be understood that there is one such relay in each phase and that each is connected in series with the interrupting switch 5 in its corresponding phase.

If any series coil 6 of a relay 3 is traversed by minimum trip current, which is usually twice the rated load current of the recloser, it attracts its associated mag netic armature 7 causing a downward movement of a vertical link 8 attached to the armature 7. Vertical movement of link 8 causes the clockwise rotation of an L-shaped lever 9iaround pivot point 10 through the agency of a pair of pins 11 disposed in a spaced relation on the vertical link 8' and on either side of one end of an L-shaped lever 9. As the L-shaped lever 9 rotates, it engages a pin 13 carried by a common trip bar '12 driving said trip bar to the right as viewed in Fig. 1. It will be understood that each phase is provided with a similar arrangement for driving the com mon trip bar 12 in response tooccurrence-ofovercui' rent, only one such arrangement being shownfqr recloser taken sake of brevity. The trip bar 12 is providednear its left end with a traverse driving pin 13 that engages the end of a rocking lever 14 carried on the end of a trip shaft 15. Moveme'nt of trip' bar 12 to the rightrotates the trip shaft 15 counterclockwise to effect tripping of the recloser ina manner-to be described hereinafter.

The interrupting switch of each phase is carried by an associated

bell crank

18, 19 and 20, each of which is shaped somewhat differently so that they may perform their individual functions. Each bell crank is adapted to pivot on a fixed pivot 21 and each is further pivotally connected at pivots designated 22 to a common power bar '23 to which a switch opening spring 24 is attached. Under normal circuit conditions, when the recloser is closed as shown in Fig. l, the opening spring 24 tends to shift the power bar 23 to the right and thereby rotate bell cranks '18, 19 and 20 simultaneously in a clockwise direction to open the various switches 5 by a force transmitted from the bell cranks through the insulating switch links 25. Such opening action is, however, normally prevented by a collapsible general latch means or toggle link assembly generally designated by the reference numeral 28. When the toggle link assembly 28 is in rigid condition, it restrains the power bar 23 and accordingly the switches '5 from being operated by the power spring '24.

When the recloser is closed, the/toggle link assembly '28 effects a rigid connection between a bell crank 18 and a rocking lever 29, the latter of which is normally latched and participates in a switch resetting operation to be explained. The toggle link assembly 28 comprises'a long link 30 pivotally connected near its mid section bya pivot pin -31 to a triangularly shaped link 32 which in turn is pivotally connected to the rocking lever 29 at 33. The tendency for the elongated link 30 is to rotate in a clockwise direction under the influence of opening spring 24 acting on the power bar 23 but this is normally prevented by a hemispherical latch release shaft '34 that is pivotally mounted on triangular link 32 and which shaft 34 acts as a stop for link 30. The hemispherical or half shaft 34 is provided with two ears, one of which is normally biased against a stop pin 35 by a small spring 36 that is an chored to the triangular link 32. The tip 30' of the elongated link 30 bears inlow frictional relation on the outer periphery of the half shaft 34 so that if the latter is rotated, said tip will move past the flattened portion of said half shaft and allow rotation of the toggle links 30 and 32. The other ear 35' is engaged by arm 16 carried on the opposite end of trip shaft 15. It can be seen that counter clockwise rotation of the trip shaft due to the downward movement of armature 7 as described earlier will cause clockwise rotation of half shaft 34 against the force of the biasing spring 36 allowing tip 30 to move past flattened portion 34 so that the toggle links 30 and 32 are free to rotate. Upon this event, bell cranks 18, 19 and rotate clockwise through a limited angle opening main switches 5.

The rocking lever 29 referred to earlier is carried on a rock shaft 37 that is journaled in bearings supported by chassis, neither the chassis nor bearings being shown. The rock shaft 37 and the rocking lever 29 remain inactive until the interrupter switches 5 are fully open as a result of the latching of rocking lever 29 by a latch arm 38 that is biased by a spring 39 in a clock wise direction around a fixed pivot pin 40 against a stop pin 41. The latch arm 38 normally engages and anchors the rocking lever 29, as shown in Fig. 1, when the recloser is closed. When the recloser reaches the fully open position, however, the center bell crank 19 swings clockwise and engages the latch lever 38 freeing the rocking lever 29. The rocking lever 29 then rotates counter clockwise under the influence of a spring 42 and causes the toggle assembly 28 to be reset in rigid 76 condition in preparation for the power bar 23 being moved to the left so that the various main interrupting switches 5 may again be reclosed simultaneously. During the brief interval immediately following the opening of the main interrupting switches 5 and during which time the toggle assembly 28 is set, the rotation of the rocking lever 29 also elevates a resetting magnetic plunger 45 to which it is attached by an insulating link 46.

. The resetting plunger 45 resides in a dashpot 47 surrounded by a reclosing or solenoid coil 48 that is controlled by a switch control assembly constituting the present invention and whose features and mode of operation will be described in detail hereinafter. It will be suflicient to say here that secondary switch control means 50 places the reclosing coil 48 in circuit with a source of electrical energy, which in the illustrated embodiment is between two of the phases, when the recloser switches 5 are fully open provided lockout has not been reached. As will later be evident, during lockout the secondary switch operating or control means 50 is held open and the closing coil 38 will remain de-energized. Upon the energization of the reclosing coil 48, the resetting magnetic plunger 45 is attracted downwardly whereupon the rocking lever 29 is rotated in a clockwise direction reclosing main interrupting switches 5 and extending the opening "spring 14 to store energy therein 'for the next opening operation. Rotation of the rocking lever 29 also results in the operation of the secondary switch control means 50 to tie-energize the reclosing coil 48.

Lockout means are provided for preventing reclosure of the apparatus if a fault does not clear after a predetermined number of recloser opening operations, usually four. The lockout means, schematically shown in Fig.1, is of the hydraulic type and utilizes the dielectric fluid in the recloser tank as a hydraulic medium. Such lockout means includes a pump 53 having a pump piston 54 driven by angular gyrations of the rock shaft 37 each time the recloser operates by way of a pump arm 55 and a link 56. A spring biased ball check valve 57 is provided so that the pump piston 54 does effective work only in its downward stroke. The output of the pump ,pis ton 54 is delivered to the pressure side of a countingpiston 58 through another ball check assembly 59. As the recloser operates repeatedly, the counting piston 58 is forced hydraulically to the right in a step-by-step manner causing a corresponding movement of a lockout stem 60 which is attached thereto. Lockout of the recloser is brought about by a lever 62 pivoted on stationary pivot point 63 that depresses the auxiliary switch operating means 50 to open position until manually reset. The angular position of the auxiliary switch control lever 62 is controlled by an elongated link 64. Elongated link 64 is positioned by a latch mechanism generally designated by the reference numeral 66 that includes a latch link 67 whose tip 67' normally bears on the shoulder 68 of a lockout latch lever 69. The lockout latch lever 69 is carried on the same shaft 70 as a short lever 71 that is adapted to be driven by the lockout stem 60 when the latter reaches its farthest position to the right due to the step-by-step movement of lockout piston 58. Consequently, when the lockout stem 61 strikes lever 71, the lockout latch lever 69 is rotated to the right against a holding spring 74 and thereby releases latch link tip 67' so that link 67 is rotated in a clockwise direction by a spring 75 causing the translation of long link 64 to the right. This imparts a counter clockwise movement to the auxiliary switch controlling lever 62 and results in the latter depressing a link 76 of the auxiliary switch control means 50 downwardly to prevent the re-energization of the reclosing coil 48 and thereby effecting lockout of the recloser.

' If the number of overcurrent responses is less than that required to cause"lockout,- the counting piston 58 resettles to its initial position under the influence of a resetting spring 61 which retracts stem 60 to the left after a predetermined time, governed primarily by leakage about the counting piston 58 and through ball check 59.

The shoulder 68 of lockout lever 69 and the latch link tip 67 may be re-engaged by manually rotating a resetting lever 72 through the agency of a manual operating handle 73. This allows the auxiliary switch means 50 to close and re-energize the reclosing coil 48 so that the resetting magnetic plunger 45 may be attracted to drive the various main switches 5 to their closed positions through the agency of the toggle link mechanism 28, bell cranks 18, .19 and 20 and the power bar 23.

Manual lockout of the recloser may be accomplished by rotating the manual operating handle 73 clockwise through approximately a right angle so as to cause lever 72 to pry the lockout lever 69 in a clockwise direction and thereby release the latch lever 67 as in the case of automatic lockout. However, since manual lockout is initiated when the main switches are closed, it is necessary to break the general latch means or toggle link mechanism 28. This is done by providing the lockout shaft 70 with a short arm 77 at its foremost end in Fig. 1 which engages a strike pin 78 carried by the common trip bar 9. Hence, rotation of shaft 70 causes the trip bar 9 to be translated to the right and the latch control shaft 15 being rotated in a counter clockwise direction so as to'cause the half shaft 34 to release the tip of elongated link 30 forming part of the general latch means 38 whereupon the line switches 5 open and the auxiliary switch control means 50 is again depressed open and'maintained that way until manually reset.

The secondary switch control means 50 according to the invention generally includes a means for opening the secondary switch 109 when the voltage applied to the reclosing coil 48 is only a fraction of normal. This means includes a toggle linkage mechanism 98 coupled to the rock shaft 29 through a motion multiplying linkage 99 so that only a fraction of the normal movement of the reclosing magnetic plunger 45 is necessary to overtoggle the toggle linkage mechanism 98 and open the secondary contact means.

The toggle linkage mechanism 98 includes a pair of

links

100 and 101 adapted to swivel on a common fixed pivot 102. Opposite ends of'the

links

100 and 101 are connected through the agency of an over center spring 103. The toggle linkage mechanism 98 is actuated by the motion multiplying linkage 99 which includes an arm 104 fixedly mounted at one end on rock shaft 37 and an intermediate link 105 connecting the free end of arm 104 to link 100 at a point adjacent the fixed pivot point 102' a A preferred embodiment of the contact structure 109 is shown in Fig. 9 and includes a pair of bell cranks 110 pivoted around pins 112and each has a button contact 114 at one end thereof which cooperates with fixed contacts 115 to close the circuit through reclosing coil 48. The other end of hell cranks 110 are each disposed between a pair of parallel spaced members 116 and 117 projecting laterally from each of the arms of a cross memher 118 at the lower end of the contact actuating link 76. -It can be seen that when link 76 moves downward, contacts 114 are rotated away from the fixed contact buttons 115 thereby open circuiting the reclosing coil 48. On the other hand, upward movement of contact actuating link 76 rotates contacts 114 toward the fixed contacts 115 to energize reclosing coil 48. Upon the energizing of the reclosing coil 48 the resetting magnetic plunger 45 is attracted. downwardly causing the clockwise rotation of the rocking lever 29. Fig. 9 also shows the relationship between the lockout piston 53 and the reclosing magnetic plunger 45. It will be recalled that each time rock shaft 37 is rotated due to downward actuation of the resetting magnetic plunger 45 after an opening operation of the reclosure, pump piston 53 is depressed fore ing fluid below the counting piston 58.

The operation of the auxiliary switch control means 50 will be explained with reference to Figs. 2-5. The initial position of the auxiliary switch control means 50 is shown by full lines in Fig. 2 while its position after a normal operation, in which contacts 114 are closed, is shown by dotted lines. It will be recalled that rocking lever 29 and rock shaft 37 are held inactive by the latch arm 38 until the main interrupting switches 5 reach their fully opened position at which time bell crank 19 strikes the latch arm 38 thereby releasing the rocking lever 29 and the rock shaft 37 for counter clockwise rotation under the influence of spring 42. As the rock shaft 37 rotates through a small counter clockwise angle, arm 104 rocks in a counter clockwise direction swinging link in a clockwise direction around the fixed pivot point 102 through agency of the intermediate link 105. During this initial movement of link 100, link 101 remains stationary. Link 100 will continue to pivot until its axis is parallel to the axis of link 101 at which time the line of action of the overcenter spring 103 will be parallel with the longitudinal axis of the

links

100 and 101. This is called the on-center position. As link 100 continues to swing past the oncenter position, the over'center spring 103 will snap link .101 in a counter clockwise direction around the fixed pivot point 102 from the position shown by full lines in Fig. 2 to the position shown by dotted lines. This draws link 76 upward rotating bell cranks 110 outwardly to close the circuit through reclosing coil 48.

When normal voltage is applied to the reclosing coil 48 the resetting magnetic plunger 45 will be attracted downwardly thereby pivoting the rocking lever 29 clockwise from the dotted to the full position in Fig. 2. This rotates the rock shaft 37 in a clockwise direction pivoting arm 104 downward from the dotted position toward the full position in Fig. 2, causing the counter clockwise rotation of link 100 around the fixed pivot point 102. As link 100 passes the on-center position wherein it is coaxial with the dotted position of link 101 in Fig. 2, the overcenter spring 103 snaps link 101 from the dotted to the full position forcing the contact actuating link 76 downward to open the circuit through the reclosing coil 48.

If less than normal voltage is placed across the reclosing coil 48, the downward travel of the magnetic reclosing plunger 45 will be only a fraction of normal so that ,g

remain closed resulting in overheating of the coil unless expensive auxiliary equipment such as potential transformer operated relays were provided to open the reclosing coil circuit.

The operation of the auxiliary switch operating means 50 during under voltage conditions is shown in Figs. 3-5. In general if the magnitude of the under voltage is such that the downward. movement of reclosing magnetic plunger is sufficient to carry the end of the rocking lever 29 from its initial position A to point A" wherein link 101 passes over the on-center position, the toggle mechanism 98 will open auxiliary contacts 109 even though the distance between points A and A" is only a fraction of the normaldistance travelled by the end of rocking lever 29. This occurs because the intermediate link connects arm 104 to link 100 adjacent fixed pivot point 102 so that rotational multiplication is achieved between arm 104 and link 100. More specifically, as the resetting magnetic plunger 45 rotates the end of rocking lever 29 end of link. 101 fromposition B to position B thereby opening the auxiliary contacts 109 and dc-energizing the reclosing coil 48. Hence because of the motion multiplication achieved between arm 104 and link 100 only a fraction of normal voltage is necessary to open the circuit through reclosing coil 48.

It"will be appreciated that during an under voltage, condition the magnitude of the downward movement of reclosing magnetic plunger 45 may also be insufiicient to reclose themain interrupting switches 5. The recloser will 'go to lockout without the operation of the main interrupting switches, however, due to cycling action of the auxiliary switch operating means 50. Referring now to Fig. 1, if the downward movement of the-reclosing magnetic plunger 45 is insufficient to. close the main interrupting switches 5, the rotation of rocking lever 29 will beinsuflicient to re-engagev latch lever 38. Therefore, after the reclosing magnetic plunger 45 has reached the lowest point in its downward plunge, rocking lever 29 is ,again free to rotate in a counter clockwise direction under the influence of spring 42. This actuates the auxiliary switch control means50 to close contacts 109 in the manner discussed with respect to Fig. 2. .If normal voltage conditions have returned, the main interrupting switches will ,be reclosed by the normal downward travel ofthe resetting magnetic plunger 45. However, if the under voltage persists, only fractional downward movement of resetting magnetic plunger 45 will'again result whereby the secondary contacts 109 are again reopened injthe manner discussed with respect to Figs. -35. After the fractional downward movement of the resetting magnetic plunger 45 is completed, rocker arm 29 .will again befreeto rotate in a counter clockwise direction thereby reelosing the secondary contacts 109. and .theprocess is repeated. Upon each counter clockwise rotation of rock- .ing lever 29, pump arm 55 will be rotated driving pump piston 53 so that a quantity of fluid is delivered to countingpiston SS. This. of course. drives lockout stem 60 toward the lockout position. As can. be seeninFig. 2,

theangular travel of pump arm.55.during a normal pumping operation is through an angle 0. Fig. 5, however, shows that the angular travel of pump arm 55 during undervoltage conditions is through a smaller angle a. It will, thus be appreciated that a greater number of cycles aretherefore necessary to drive lockout stem 60 to lockoutposition during under voltage conditions than during normal operating conditions.

A preferred embodiment of the auxiliary switch operating mechanism according to the invention is shown in Figs.,68. Arm 104 comprises a triangularly shaped member rigidly coupled to rock shaft 37 through the agency of bolt 125 and member 126 fixedto rock shaft 37 by means of pin 128. Spacers 130 maintain arm 104 at the proper distances from member 126 and the frame 132.

Links

100, 101 and 105 and the over-center spring 103 each comprises a pair of parallel members symmetricallydisposed with respect to arm 104; Fixed pivot point 102 for one end of

links

100 and 101 is provided by means of a pin 135 extending throughthe upper end of an L-shaped bracket member 134 rigidly secured at its lower end to frame 132. The other end of links 101 are pivotally coupled to the switch actuating'link 76 by a pin 136. -One end of the over-center springs 103 is securred to pin'136 and the-:other .end of said springs arefixed to lugs 138 carried on each of the free ends of links 100. A pin 137 pivotally connects one end of links .105 to either side -of arm 104 while the other end of each of said links 105 pivotally engagesone of the links 100 adjacent the fixed pivot 102 through the agency of a pin 139. tProper spacing is maintained between the rock shaft 37 and theswitch actuating link 76 .bymeans of member 140 having its opposite ends loosely coupled to pin 138 and rock shaft 37.

Fig; 10 shows an alternate embodiment of the motion multiplying linkage wherein arm 104" is directly coupled to link by means of a slot formed-in the free end of arm 104' which engages a pin 152 carried by link 100 near fixed pivot point 102. The operation-of this embodiment is similar to that of the preferred embodilink 100 passes the on-center position, over-center spring 103 will snaplinks 100 and 101 to the dotted position in Fig. 10 opening the secondarycontacts while arm 104' continues to its dotted position in Fig. 10. Because thefinal position of slot 150 is remote from pin 152, the upper portion 156 of arm 104' which defines the upper margin of slot 150' is so proportioned that pin 152 and slot 150 may separate after link 100 passes the on-center position. After this separation arm 104' and link 100 continue to rotate to the dotted positions in Fig. 10, the rotation of link 100 beinglimited by stop 160. The lower portion 156 of arm 104 extends beyond the edge of upper portion 154 and is so proportionedthat after arm 104 has rotated counter clockwise a portion of the distance from the dotted to the full position in Fig. 10

upon the opening of the main switches 5, pin 152 will be engaged by said lower portion 156. This re-engages pin 152 with slot 150. As arm 104 continuesto rotate to. the full position in Fig. 10, link 100' will rotate clockwise past the on-center positionto close the secondary contacts;

Although the invention has been described in considerable detail in reference to oneschematically repre sented recloser, this is not to be construed as limiting the invention to the particular recloser shown, for the-- invention may be embodied in' other polyphase or single phase reclosers. The invention having been described with reference to two embodiments, various modifications thereof will appear to those skilled in the'art and it '-is intended to cover in the appended claims'all such modifications as fall within the true spirit and scope of the*' invention.

I claim:

1. A repeating circuit interrupter comprising switch means, means for opening said'prirnary switch means on overload, electro-responsive means for closing said primary switch means, control means for completing an energizing circuit to said electromotive means upon the opening of said primary switch means and for opening said energizing circuit upon the closing of the primary switch means, said control means including means for de energizing said electromotive means when the voltage ofsaid circuit is insuificient to resultin'norm'al operation thereof to close said primary switch means.

2. A repeating circuit interrupter comprising primary switch means, means for opening said primary switch, means on overload, electromotive means for closin'g'said primary switch means, a source of electrical energy, it secondary swith means coupled to said primary switch means and operable on the opening of said primary switch means to place said electromotive means in circuit with" said source of electrical energy, and means for reopening said secondary switch meanswhen the voltage of said source falls below a predetermined value and after said primary switch means has executed an opening operation. 3. A repeating circuit interrupter comprising primary switch means, means. forv opening said primary switch means on overload, electromotive means for closing s'aid' primary switch means,"a source of electrical energy, sec ondary switch 1 means coupled to said primary switch-" means and operable on the opening of said primary switch J means to place said electromotive means in circuit with said source of electrical energy, cumulative lockout means operative simultaneously in a step-by-step manner with each operation of said secondary switch means, and means for reopening said secondary switch means when the voltage of said source falls below a predetermined value and after said primary switch means has executed an opening operation.

4. A repeating circuit interrupter comprising primary switch means, means for opening said primary switch means on overload, electromotive means for closing said primary switch means, a source of electrical energy, secondary switch means coupled to said primary switch means and operable on the opening of said primary switch means to place said electromotive means in circuit with said source of electrical energy and also operalble upon the closing of said primary contacts to de-energize said electromotive means, said electromotive means also being operatively coupled to said secondary switch means for open circuiting said electnomotive means when the voltage of said source is insufficient to close said primary switch means. r

5. A repeating circuit interrupter comprising primary switch means, means for opening said primary switch means on overload, electromagnetic means including an operating coil and an armature for closing said primary switch means, secondary switch means operable upon the opening of said primary switch means to place said operating coil in circuit with a source of electrical energy, means coupling said armature means to said secondary switch means for opening said secondary switch means upon the operation of said electromagnetic means to de-energize said operating coil, said coupling means including motion multiplying means whereby a partial stroke of said armature incident to an under voltage will effect de-energization of said operating coil.

6. A repeating circuit interrupter comprising primary switch means, means for opening said primary switch means on overload, electromagnetic means including an operating coil and an armature for closing said primary switch means, a source of electrical energy, secondary switch means operable upon the opening of said primary switch means to place said operating coil in circuit with said source of electrical energy, coupling means including toggle linkage means operatively coupling said armature to said secondary switch means for opening said secondary switch means to de-energize said operating coil upon the operation of said electromagnetic means, said coupling means also including motion multiplying means whereby a partial stroke of said armature, incident to an under voltage will efllect opening of said secondary contacts.

7. A repeating circuit interrupter comprising primary switch means, means for opening said primary switch means on overload, electromagnetic means for closing said primary switch means, said electromagnetic means including an operating coil and an armature, secondary switch means, a source of electrical energy, secondary switch actuating means operable upon the opening of said primary switch means to place said operating coil means in circuit with a source of electrical energy, said actuating means including toggle linkage means and coupling means for coupling said toggle linkage means to said armature so that said secondary switch means will be opened upon the actuation of said solenoid, said coupling means including motion multiplying means so that partial movement of said armature incident to an under voltage of said source 'which is insuflicient to reclose said primary contacts will open said secondary contacts, means for reclosing said secondary switch means upon the occurrence of such under voltage, and cumulative lockout means for said secondary switch means operable in a step-by-step manner with each operation of said secondary switch means, whereby said secondary switch means will cycle to lockout upon the occurrence of such under voltage.

8. A repeating circuit interrupter comprising primary switch means, means for opening said primary switch means on overload, electromagnetic means for closing said primary switch means including an operating coil and an armature, a source of electrical energy, a secondary switch means for placing said operating coil in circuit with said source of electrical energy, secondary switch actuating means including toggle linkage means and motion multiplying means, said toggle linkage means including a pair of links each pivoted at one end at a fixed pivot point and means for resiliently biasing the free ends of said links toward each other, the free end of one of said links being operatively coupled to said secondary switch means so that movement of said free end in one direction will open said secondary switch means and movement thereof in an opposite direction will close said secondary switch means, said motion multiplying means including an arm coupled to the other of said links adjacent said fixed pivot point so that fractional rotation of said arm will over toggle said toggle linkage means, said arm also being operatively coupled to said primary switch means and to said armature and adapted to be rotated in a first direction in response to the open ing of said primary switch means to toggle the free end of said one link in said one direction, thereby opening said secondary switch means and to be moved in a second direction in response to the actuation of said armature to toggle the free end of said one link in said opposite direction to thereby close said secondary switch means whereby said secondary switch means will be opened upon fractional movement of said armature incident to an under voltage of said source which is insufiicient to reclose said primary contacts.

9. A repeating circuit interrupter comprising primary switch means, means for opening said primary switch means on overload, electromagnetic means for closing said primary switch means including an operating coil and an armature, a source of electrical energy, a secondary switch means for placing said operating coil in circuit with said source of electrical energy, secondary s witch actuating means including toggle linkage means and motion multiplying means, said toggle linkage means including a pair of links each pivoted at one end at a fixed pivot point and means for resiliently biasing the free ends of said links toward each other, the free end of one of said links being operatively coupled to said secondary switch means so that movement of said free end in one direction will open said secondary switch means so that movement thereof in an opposite direction will close said secondary switch means, said motion multiplying means including an arm and a third link coupling said arm to the other of said links at a point adjacent said fixed pivot point so that fractional rotation of said arm will over toggle said toggle linkage means, said arm also being operatively coupled to said pri mary switch means and to said armature and adapted to be rotated in a first direction in response to the opening of said primary switch means to toggle the free end of said one link in said one direction, thereby opening said secondary switch means and to be rotated in a second direction in response to the actuation of said armature to toggle the free end of said one link in said opposite direction to thereby close said secondary switch means, whereby said secondary switch means will be opened upon fractional movement of said armature incident to an under voltage of said source which is insuflicient to reclose said primary contacts.

No references cited.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Nob 21,898A231 August A}, 3959 Ks zuo Usv LE printed specification It is hereby certified that error appears in the that the said Letters of the above numbered patent requiring correction and Patent should read as corrected below.

COlUITd'l 8, lines 51 and 55, strike out "electromotive", each occurrence, and insert instead e1ectro-responsive W Signed and sealed this 23rd day of February 1960.

(SEAL) Attest:

KARL H AI QLLEE ROBERT C. WATSQN Commissioner of Patents Attesting Officer UNITED STATES PATENT OFFICE QTEFIQATE OF CORRECTION August 4, 1959 Patent No, 23898,;21

Kazuo Henry Date s in the printed specification It is hereby certified that error appear v d that the said Letters of the above numbered patent requiring correction an Patent should read as corrected below.

olumn 8, lines 51 and 55, strike out "electromotive", each occurrence,

0 and insert instead w electro responsive aw Signed sealed this 23rd day of February 1960,

(SEAL) Attest:

AXLINE ROBERT WATSON Commissioner of Patents Attesting Officer