CA1104620A - Circuit breaker with dual drive means capability - Google Patents

Abstract

46,792 CIRCUIT BREAKER WITH DUAL DRIVE MEANS CAPABILITY

ABSTRACT OF THE DISCLOSURE
A circuit breaker having stationary and movable contacts operable between open and closed positions with the movable contact being biased in an open position. The movable contact is mounted to a contact holder which engages one link in a toggle means. The first link is connected to a second link which has a drive pin secured thereto, and the second link is pivotally connected to a toggle lever. A cam is secured to a rotatable drive shaft, and the cam engages a cam roller which is secured to a follower plate. The fol-lower plate has a drive pawl attached thereto, with the drive pawl being disposed adjacent the drive pin. Spring means are pivotally connected to the follower plate and are capable of being in spring charged and discharged positions.
The spring is charged by rotation of the drive shaft and cam causing the cam roller to move outwardly. The outward move-ment of the cam roller causes rotation of the follower plate, resulting in charging of the spring means. When the spring means discharges, it causes rotation of the follower plate such that the drive pawl is capable of engaging the drive pin to move the toggle means into toggle position.
Upon moving into toggle position, the toggle means moves the contact holder and movable contact into closed position.
Also included are releasable toggle and drive latch means for holding the toggle means in toggle position and the follower plate in the spring charged position, respectively.
An insulating barrier is disposed between the movable contact and the operating mechanism to electrically isolate 46,792 the current carrying parts from the operating mechanism.
Means for rotating the drive shaft include a handle secured to the drive shaft and a motor operator having a rotatable output shaft which is capable of engaging the drive shaft and which can be easily installed.

Description

BACKGROUND OF THE INVENTION
- This invention relates generally to single or .~ .
... . .

4~, 792 11~46~

multi-pole circuit breakers, and more particularly to stored energy circuit breakers having manual and motor operated drive means.
The basic functions of circuit breakers are to provide electrical system protection and coordination when-ever abnormalities occur on any part of the system. The operating voltage, continuous current, frequency, short circuit interrupting capability, and time-current coordina-tion needed are some of the factors which must be considered when designing a breaker. Government and industry are placing increasing demands upon the electrical industry for interrupters with improved performance in a smaller package and with numerous new and novel features.
Stored energy mechanisms for use in circuit breakers of the single pole or multi-pole type have been known in the art. A particular construction of such mechan-isms is primarily dependent upon the parameters such as rating of the breaker Needless to say, many stored energy circuit breakers having closing springs cannot ~e charged while the circuit breaker is in operation. For that reason, some circuit breakers have the disadvantage of not always being ready to close in a moment's notice. These circuit breakers do not have, for example, an open-close-open feature which users o~ the equipment find desirable.
Another problem present in some prior art circuit breakers is that associated with matching the spring torque curve to the breaker loading. These prior art breakers utilize charging and discharging strokes which are each 1&0. The resulting spring torque curve is predetermir-ed, 0 and usually cannot be matched with the breaker loading~.

46,792 6;~) Such a predetermined curve mandates that the elements asso-ciated with the breaker be matched for this peak torque rather than be matched with the breaker load curve.
A desirable characteristic in these circuit break-ers is for the current carrying parts to be electrically isolated from the operating mechanism of the breaker. By so isolating the current carrying parts, temporary emergency repairs to the operating mechanism ma~ be undertaken.
Another desirable characteristic in these circuit breakers is to provide for both manual and motor driven operation of the operating mechanism. This dual capability should be provided so that critical alignment of the connec-tion of the motor to the operating mechanism is not necessary, and this connection of the motor to the operating mechanism should also be capable of being easily installed in the field in the unlikely event of a motor failure.
SUMMARY OF THE INVENTION
In accordance with this invention, it has been found that a more desirable stored energy circuit breaker is provided which comprises stationary and movable contacts operable between open and closed positions with respect to the stationary contact. Means for effecting movement of the movable contact between the open and closed positions are included, and these movement effecting means include a rotatable drive shaft havlng an end, a drive handle secured to the drive shaft for imparting rotation thereto, and a motor operator having a rotatable output shaft which is capable of engaging the drive shaft to also impart rotation to the drive shaft.

46,792 ~ 6 ~ 0 BRIEF DESCRIPTION OF THE DRAWINGS
Referenee is now made to the description of the preferred embodiment, illustrated in the accompanying draw-ings, in whieh:
Figure 1 is an elevational sectional view of a eircuit breaker aeeording to the teaehings of this invention;
Figure 2 is an end view taken along line II-II of Fi.gure l;
Figure 3 is a plan view of the meehanism illus-trated in Figure 4;
Figure 4 is a detailed sectional view of the oper-ating mechanism of the circuit breaker in the spring dis-eharged, contact open position;
Figure 5 is a modifieation of a view in Figure 4 with the spring partially eharged and the eontaet in the open position;
Figure 6 is a modifieation of the views illustrated in Figures 4 and 5 with the spring charged and the contaet open;
Figure 7 is a modifieation of the view of Figures 4, 5, and 6 in the spring discharged, contact closed posi-tion;
Figure 8 is a modif`ication of the view of Figures 4, 5, 6, and 7 with the spring partially charged and the contact closed;
Figure 9 is a modification of the view of Figures 4, 5, 6, 7, and 8 with the spring charged and the contact closed;
Figure 10 a plan view of a current carrying contact 3 system;

~4~ZU 46.792 Figure 11 is a side, sectional view of the current conducting system;
Figure 12 is a detailed view of the movable contact;
Figure 13 is a side view of the cross arm structure;
Figure 14 is a modification of the multi-pole contact structure;
Figure 15 is an end view of the connection of the motor operator shaft to the drive shaft;
Figure 16 is a modification of the view of Figure 15;
Figure 17 is a side view of the connection of the motor operator to the drive shaft;
Figure 18 is a modification of the view of Figure 17; and Figure 19 is a modification of the view of Figure 18.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now more particularly to Figure 1, therein is shown a circuit breaker util.izing the teach~ngs of this invention. The circuit breaker 10 includes support 12 which is comprised of a mounting base 14, side walls 16, support walls 13~ 15, and a frame structure 18. The mounting base 14 and support walls 13, 15 are, in the preferred embodiment, molded of an electrically insulating mater~al such as plastic. A pair of stationary contacts 20, 22 are disposed within the support 12, with the support walls 13, 15 disposed between adjacent pairs of stationary contacts 20, 22. Stationary contact 22 would, for example, be con-nected to an incoming power line (not shown), while the other stationary contact 20 would be connected to the load ~V~6Z~ 46, 792 (not shown). Electrically connecting the two stationary contacts 20, 22 is a movable contact structure 24. The movable contact structure 24 comprises a movable contact 26, a movable arcing contact 28, a contact carrier 30 and contact holder 64. The movable contact 26 and the arcing contact 28 are pivotally secured to the stationar~ contact 20, and are capable of being in open and closed positions with respect to the stationary contact 22. Throughout this application, the term "open" as used with respect to the contact positions means that the movable contacts 26, 28 are spaced apart from the stationary contact 22, whereas the term "closed" indicates the position wherein the movable contacts 26, 28 are contact-ing both stationary contacts 22 and 20. The movable contacts 26, 28 are mounted to and carried by the contact carrier 30 and contact holder 64.
Also included within the circuit breaker 10 is an operating mechanism 32, a toggle means 34, and an arc chute 36 which extinguishes any arc which may be present when the movable contacts 26, 28 change from the closed to open posi-tion. A current transformer 38 is utilized to monitor theamount of current flowing through the stationary contact 20.
Electrically insulating the live elements, such as the contacts 26, 28 from the operating mechanism 32 and toggle means 34 is an insulating barrier 33. The barrier 33 is disposed intermediate the contact holder 64 and the operating mechanism 32 and toggle means 34.
Referring now to Figure 12, there is shown a de-tailed view of the movable contact 26. The movable contact 26 is of a good electrically conducting material such as copper, and has a contact surface 40 which mates with a 1~4~ 46,792 similar con~act surface 42 (~ee Figure 1~ of stationary contact 22 whenever the movable contact 26 is in the closed position. The movable contact 26 has a circular segment 44 cut out at the end opposite to the contact surface 40, and also has a slotted portion' 46 extending along the movable contact 26 from the removed circular segment 44. At the end of the slot 46 is an opening 48. The movable contact 26 also has a depression 50 at the end thereof opposite the contact surface 40.
The circular segment 44 of the movable contact 26 is sized so as to engage a circular segment 52 which is part of the stationary contact 20 ( see Figure 11). The circular segment 44 and the slot 46 are utilized to clamp about the circular segment 52 to thereby allow pivotin~ of the movable contact 26 while maintaining electrical cont;act with the stationary contact 20. As shown in Figure 11, the arcing contact 28 is designed similarly to the movable contact 26, except that the arcing contact 28 extends outwardly beyond the movable contact 26 and provides an arcing mating surface 20 54 which contact a similarly disposed surface 56 on the stationary contact 22. The arcing contact 2~ and the movable contact 26 are mounted to, and carried by a contact carrier 30. A pin 58 extends through the openings 48 in the movable contact 26 and the arcing contact 28, and this pin 58 extends outwardly to, and is secured to, the contact carrier 30.
The contact carrier 30 is secured by screws 60, 62 to a contact and spring holder 64. The contact and spring holder 64 is typically of a molded plastic. By so constructing the connections o~ the movable contact 26 to the contact carrier 3Q 30, the movable contacts 26 are permitted a small degree o~

46 ~ 792 freedom with respect to each other. To maintain contact pressure between the movable contact surface 40 and the stationary contact surface 42 when the movable contact 26 is in the closed position, a spring 66 is disposed within the recess 50 of the movable contact 26 and is secured to the spring holder 64 ( see Figure 10). The spring 66 resists the forces which may be tendini~ to separ~te the movable contacts 26 from the stationary contact 22.
Also shown in Figure lG is a cross arm 68 which extends between the individual contact holders 64. The cross arm 68 assures that each of the three poles illustrated will move simultaneously upon movement of the operating mechanism 32 to drive the contacts 26, 28 into closed or open position. As shown in Figure 13, the cross arm 68 extends within an opening 70 :in the contact holder 64 and through openings 69, 71 in support walls 13, 15 (see Figure

2) . A pin 72 extends through an openini~, 74 in the contact holder 64 and an opening 76 in the cross arm 68 to prevent the cross arm 68 from sliding out of the contact holder 64.
Also attached to the cross arm 58 are pusher rods 78. The pusher rods 78 have an opening 80 therein, and the cross arm 68 extends through the pusher rod openings 80. The pusher rod 78 has a tapered end porticn 82, and a shoulder portion 84. The pusher rod 78, and more part.ii-ularly the tapered portion 82 extends into openings i86 within the support walls 13~ 15 (see Figure 2~ and disposed around the pusher rods 78 are springs 88. These springs 38 function to exert a force against the shoulder 84 of the pushe~ rod 78, thereby biasing t.he cross arm 68 and the mov~le colltac1-s 26 in the open position. To close the movabli lonta~ts 26, it is necessary _9_ 46,79~

to move the cross arm 68 such that the pusher rods 78 will compress the spring 88. This movement is accomplished through the operating mechanism 32 and the toggle means 34.
Referring now to Figures 2-4, there is shown the toggle means 34 and the operating mechanism 32. The toggle means 34 comprise a first link 90, a second link 92, and a toggle lever 94. The first link 90 is comprised of a pair of spaced-apart first link elements 96, 98, each of which have a slot 100 therein. The first link elements 96, 98, extend through an opening 87, 89 respectively in the insu-lating barrier 33, and within openings 75, 77 in the support walls 13, 15 respectively. The first link elements 96, 98 and the slot 100 engage the cross arm 68 intermediate the three contact holders 64, and provide movement of the cross arm 68 upon the link 90 going into toggle position. The location of the link elements 96, 98 intermediate the contact holders 64 reduces any deflection of the cross arm 68 under high short circuit forces. Also, the use of the slot 100 to connect to the cross arm 68 provides for easy removal of the 20 operating mechanism 32 from the cross arm 68. Although described with respect to the three-pole breaker illustrated in Figure 2, it is to be understood that this description is likewise applicable to the four-pole breaker illustrated in Figure 14. With the four-pole breaker, the first lin~
elements 96, 98 are disposed between the interior contact holders 186, 188 and the exterior holders 187, 189. Also, if desired, an additional set of links or additional springs (not shown) may be disposed between the interior holders 186, 188. The second link 92 colnprises a pair of spaced-apart second link elements 102, ln4 which are pivot,ally -ln-~6,792 ~1~4~

connected to the first link elements 96, 98, respectively at pivot point 103. The toggle lever 94 is comprised of a pair of spaced-apart toggle lever elements 106, 108 which are pivotally connected to the second link elements 102, 104 at pivot point 107, and the toggle lever elements 106, 108 are also pivotally connected to side wails 16 at pivotal connec-tion 110. Fixedly secured to the second link elements 102, 104 are aligned drive pins 112, 114. The drive pins 112, 114 extend through aligned openings 116, 118 in the side walls 16 adjacent to the follower plates 120, 122.
The operating mechanism 32 is comprised of a drive shaft 124 rotatable about its axis 12~ having a pair of spaced apart aligned cams 126, 128 secured thereto. The cams 126, 128 are rotatable wi.th the drive shaft 124 and are shaped to provide a constant load on the turning means 129.
The turning means 129 comprise a drive handle 131 which is secured to the drive shaft 124, and a motor operator 133 having an output shaft 135 which is capable of engaging the end 137 of the drive shaft 124 to impart rotation thereto.
2~ For most efficient operation, means 139 for preventing rotation of the drive handle 131 upon rotation of the drive shaft 124 by the motor operator 133 are included. The drive handle 131 is secured to these prevention means, which may be, for example, a one way clutch or a ratchet and gear system, and these pre~ention means 139 are then secured to the drive shaft 124.
The motor operator 133 is comprised of a gear motor 141 which rotates a gear motor shaft 143 which is connected to a pair o~ cooperating gea.rs 147, 149 within the

3 gear box 14~. The motor operator output sha~t 13~ is 46,792 1~4~0 connected to the gear 149, and is turned upon rotation of the gear 149. Upon activation of the gear motor 141, the gear motor shaft 143 is rotated, causing the rotation of gear 147 which is secured thereto. The interaction of gear 147 with gear 149 through gear teeth 113, 115 causes a corresponding rotation of the gear 149, The rotation of the gear 149 causes a rotation of the r,~otor operator output shaft 135 which is secured thereto, and this motor operator output shaft 135 is capable of engaging the end 137 of the drive shaft 124 to provide rotation thereto. The connection of the motor operator output shaft 135 to the drive shaft 124 is such that the motor operator 133 is capable of being plugged into the drive shaft 124 with a minimum of effort.
Referring to Figures 15-~9, therein is shown a detailed view ~ af f~c of some ofth~ possible connections of the motor operator output shaft 135 to the end 137 of the drive shaft 124, In Figures 15 and 17, it is shown that the end 137 of the drive shaft 124 has a t,ongue 117 extending outwardly therefrom, and the motor operator output shaft 135 has a pair of spaced-apart, parallel fingers 119 which extends outwardly from the output shaft 135 and which engage the tongue 117 of the drive shaft 124 on opposite sides thereof. The fingers 119 are such that, upon rotation of the output shaft 135, they engage the tongue 117 and cause it to rotate therewith.
This rotation of the tongue ~17 causes a rotation of the drive shaft 124 of which the tongue 117 is a part, thereby providing rotation of the drive shaft 124 to power the operating mechanism 132, Figures 16, 18 and 19 provide a modification of this tongue and finger arrangement previously descrlbed~ In 46,792 ~1~46~0 Figure 16, it is shown that, instead of having a tongue 117, the output end 137 of the drive shaft 124 is provided with a pair of openings 121, and disposed within these openings are a pair of pins 123 which are part of the motor operator output shaft 135 and which extend outwardly therefrom. The pins 123 cause rotation of the drive shaft 124 upon rotation of the output shaft 135. Fig~ e 19 illustrates a modifica-tion of the pin and opening combination connection previously described. In this modificatlon, the pins 157 are secured to, and extend outwardly from the end 137 of the drive shaft 124, and openings 159 are included within the motor operator output shaft 135. This combin3tion also functions to provide rotation of the drive shaft 124 upon rotation of the motor operator output shaft 135. The pins 157 within the openings 159 are rotated upon rotation of i~he motor operator output shaft 135, causing a corresponding rotation of the drive shaft 124. In these various means for connecting the motor operator 133 to the drive shaft, l4, it can be seen that the motor operator is capable of heing plugged into the drive shaft 124 in an easily installed ~lanner, and one that does not require the dismantling of the circuit breaker 10 or

4 operating mechanism ~
The operating mechanism 32 also includes the follower plates 120, 122 which are fixedly secured together by the follower plate connector 13~ (see Figure 3). Fixedly secured to the follower plates 120, 122 iS a cam roller 132 which also functions in latching the follower plates 120, 122 in the charged position, as will be hereinafter described.
Also secured to each follower plate 120, 122 is a drive pawl 3 134, 136, respectively5 which is positioned adjacent to the 46,792 11~4~iXO

drive pins 112, 114. The drive pawls 134, 136 are pivotally secured to the follower plates 120, 122 by pins 138, 140, and are biased by the springs 142, 144.
The follower plates 122, 120 are also connected by a connecting bar 146 which extends between the two follower plates 120, 12,', an-1 pivotally connected to the connecting bar 146 are spring means 148. Spring means 148 is also pivotally connecte(1 to the support 12 by connecting rod 150.

If desired, indicating apparatus 152 (see Figure 2) may be incorporated within the breaker 10 to display the positions of the contacts 26, 28 and the spring means 148.
The operation of the circuit breaker can be best understood with reference to Figures 3-9. Figures 4-9 illustrate, in sequence, the movement of the various com-ponents as the circuit breaker 10 changes position from spring discharged, contact open, to spring charged, contact closed positions. rn Figure 4, the spring 148 is discharged, and the movable contact 26 is in the open position. Although the contacts 20, 22, and 26, 28 are not illustrated in Figures 4-9, the cross arm 68 to which they are connected is illustrated, and it is to be understood that the position of the cross arm 68 indidates the position of the movable contact 26 with respect to the stationary contact 22. To begin, the drive shaft 124 is rotated in the clockwise direction by the turning means 129. As the drive shaft 124 rotates, the cam roller 132 which is engaged therewith3 is pushed outwardly a distance equivalent to the increased diameter portion of the cam. Figure ~ illustrates the position of the elements once the cam 126 has rotated about 0 its axis 125 approximately 180 from i~s initial starting 46,792 ~ 34~20 position. As can be seen, the cam roller 132 has movedoutwardly with respect to its initial position. This movement of the cam roller 132 has caused a rotation of the follower plate 120 about its axis 107, and this rotation has stretched the spring 148 to partially charge it. Also to be noted is that the drive pawl 134 has lil~ewise rotated along with the follower plate 120. (The precedlng, and all subsequent descriptions of the movements of the various components will be made with respect to only those elements viewed in eleva-tion. Most of the components incorporated within the circuitbreaker preferably have corresponding, identical elements on the opposite side of the breaker. It is to be understood that although these descriptions will not mention these corresponding components, they behave in a manner similar to that herein described, unless otherwise indicated.) Figure 6 illustrates the position of the components once the cam 126 has further rotated. The cam roller 132 has traveled beyond the end point 151 of the cam 126, and has come into contact with a flat surfacc 153 of a latch member 154. The follower plate 12(~ has rotated about its axis 107 to its furthest extent, and the spring 148 is totally charged. ,'he drive pawl 134 has moved to its posi-tion adjacent to the drive pin 112. The latch member 154, at a second flat surface 156 thereof has rotated underneath the curved portion of a D-latch 158. In this position, the spring 148 is charged and would cause counterclockwise rotation of the follower plate 120 if it were not for the latch member 154. The surface 153 of latch member 154 is in the path of movement of the cam roller 132 as the cam roller 3 132 would move during counterclockwise rotation of the ~ O 46,792 fol].ower plate 120. Therefore, so long as the surface 153of the latch member 154 remains in this path, the cam roller 132 and the follower plate 120 fixedly secured thereto cannot move counterclockwise. The latch member 154 is held in its position in the path of the cam roller 132 by the action of the secorld surface 156 against the D-latch 158.
The latch member 154 is pivotally mounted on, but indepen-dently movable from, the drive shaft 124 (see Figures 2 and 3), and is biased by the spring 160. The force of the cam roller 132 is exerted against the surface 153 and, if not for the D-latch 158, would cause the latch member 154 to rotate about the drive shaft 124 in the clockwise direction to release the roller 132 and discharge the spring 148.
Therefore, the D-latch 158 prevents the surface 156 from moving in a clockwise direction which would thereby move the first surface 153 out of the path of movement of the cam roller 132 upon rotation of the follower plate 120. To release the latch member 154, the releasable release means 162 are depressed, which causes a clockwise rotation of D-latch 158. The cloc~wise movement of the D-latch 158 dis-engages from the second surface 156 of the latch member 154, and the latch member 154 is permitted to rotate clockwise, resulting in the movement of the first surface 153 away from the path of the cam roller 132. The results of such release is illustrated in Figure 7.
Once the latch member 154 is rel.eased, the spring 148 discharges, causing rotation of the follower plate 120 about its pivot axis 107. The rotati.on of the follower plate 120 moves the cam roller 132 into its position at the 3 smallest diameter portion of the cam 126. At the same time, ~46~ 46,792 the rotation of the follower plate 120 causes the drive pawl 134 to push against the drive pin 112. This pushing against the drive pin 112 causes the drive pin 112, and the second link element 102 to which it is connected to move to the right as illustrated in the drawing. This movement causes the second link element 102 and the first link element 96 to move into toggle position with the toggle lever element 106.
This movement into the toggle position causes movement of the cross arm 68, which compresses ~he shoulder 84 of the pusher rod 7& against the springs 88 (see Figure 2), and moves the movable contacts 26 into the closed position in electrical contact with the stationary contact 22. The movable contact 26 will remain in the closed position because of the toggle position of the toggle means 34. Once the toggle means 34 are in toggle position, they will remain there until the toggle lever g4 is released. As can be noticed from the illustration, the drive pawl 134 is now in its original position but adjacellt to the drive pin 112.
The ~irst link 90 and the second linic 92 are limited in their movement as they move into toggle position by the limiting bolt 164. This bolt ,64 prevents the two links 30, 92 from knuc~ling over backwards and moving out o~ toggle position. (Throughout this application, the term "toggle position" refers to not only that position when the first and second links are in precise alignment, but also includes the position when they are slightly over-toggled.) The status of the brea~er at this position is that the spring 14& is discharged, and the contacts 26 are losed.
~igure 8 then illustrates that the spring 148 can 3 be charged while the contacts 26 are closed, to thereb~

~4~V 46,792 store energy to provide an open-close-open series. Fi~ure 8 is si~ilar to Figure 5, in that the cam 126 has been rotated about 180, and the follower plate 120 has rotated about its pivot point 107 to partially charge the spring 148. Again, the drive pawl 134 has rotated with the follower plate.
Figure 9 illustrates the situation wherein the spring 148 is totally chargecl and the contacts ~6 are closed. The drive pawl 134 is in the same pOSitiOIl -t occupied in Figure 6, ~ co~7 fRCt except that the drive pin 112 is no longer contacted with it. The latch member 154 and more particularly the surface 153, is in the path of the cam roller 132 to thereby prevent rotation of the follower plate 120. The second surface 156 is held in its location by the D-latch 158 as previously described. In this position, it can be illustrated that the mechanism is capable of an open-clo;e-open series. Upon release of the toggle latch re~eaie meclns 166, the toggle lever 94 will no longer be kept in 1Oggle position with links 90 and 92, but will instea-l s~love slightly in the counterclockwise direction. Upon counterclockwise movement of the toggle lever 94, the second link 92 will move in the clockwise direction, pivoting about the connection with the toggle lever 94, and the first link 90 will move in the counterclockwise direction with the second link 92. Upon so moving out of toggle, the force on the cross arm 63 which pushed the pusher rod 78 against the spring Q8 will be released, and the release of the sprin, 88 ~ill force the cross arm 68 and the movable contacts 26 into the open position. This then is the position of the components as illustrated in Figure 6. To then lmnedic. el~r close the 3 contacts 26, the latch member 154 i<; re~eased, which, a~

46,792 4~

previously deseribed, eauses rotation of the follower plate 120 such that the drive pawl 134 contacts the drive pin 112 to cause movement of the drive pin 112 and the second link element 102 to which it is fixedly secured to move back into toggle position. This then results in the position of the eomponents as illustrated in Fi~ure 7. mhe breaker 10 then ean immediate]y be opened again by releasing the toggle lateh release means 166, which will position the components to the position illustrated in ~i~ure 4. Thus it can be seen that the mechanism permits a rapid open-elose-open series.
As can be appreciated from the foregoing, the operating mechanism 32 and the l;oggle means 34 are electri-cally insulated from the current carrying parts of the breaker. The movable contaets 26, 28 are held by, and carried by the contact holder 64 which is of an electrically insulating materia] such as a molded plastic. The cross arm 68 is inserted within the contact holders 64, and thereby is electrically insulated from the movable contacts 26, 28.
The first link 90 contacts and en~ages the cross arm 68, and likewise is not in direet eleetrical contact with the eurrent carrying movable contacts 26. A~l the other elements of the toggle means 34 and the operating mechanism 32 are disposed on the other side of the insulatin~, barrier 33 distal from the moving eontaets 26. ThereLc~re, emer~ency repairs to the operating mechanism 32 or the toggle means 34 may be under-taken while the movable eontacts 2c are ln the closed position.
Also, the arc chute 36 has an outer support 123 which li~;e-wise is of an insulatin~, materlal suc h as plastic, and also eleetrically insulates the arcin~r contact 25 from the oper-46,792 ~ 1~ 4 6 ~ ~

ating mechanism 32 and the toggle means 34.
In the preferred embodiment illustrated, thepositions of the various components have been determined to provide for the most economical and compacted operation.
The input shaft 124 to the operating mechanism 32 is through a rotation of approximately 360. However, the output torque occurs over a smaller angle, thereby resulting in a greater mechanical advantage. As carl be seen from the sequential illustration, the output torque occurs over an angle of less than 90. This provides a mechanical advan-tage of greater than 4 to 1. For compactness and maximum efficiency, the pivotal connection of the second link 92 to the toggle lever 94 is coincident with, but on separate shafts from, the rotational axis of the follower plates 120, 122. Another mechanical advantage is present in the toggle latch release means 166 when it is desired to release the toggle rneans 34 from toggle position.
The toggle latch release means 165 are illustrated in Figures 3 and 4. The toggle latch release means 166 are comprised of the latch member release lever 168, the two D-latches 170 and 172, the catch 174, biasing springs 176 and 178 and the stop pin 180. To release the toggle means 34, the latch member release lever 16~ is depressed. The depress-ing of this lever 168 causes a clockwise rotation of the D-latch 170. The catch 17~ which had ~een resting on the ~-latch 170 but was biased for clockwise rotation by the spring 176 ~s then permitted to move cloc~wise. The clock-wise movement of the catch 174 causes a correspollding clock-wise movement of the D-latch 172 to whose shaft 1,~ the 3 catch 174 is fixedly secured. The clockwise movement-~ the ,~

~ 1 ~ 4 6 ~ 46,792 D-latch 172 causes the latch ~ver 94, and more particularly the flat surface 182 upon which the D-latch 172 originally rested, to move, such that the surface 184 is now resting upon the D-latch 172. This then allows the toggle lever 94 to move in a counterclockwise direction, thereby releasing the toggle of the toggle means 34. After the toggle means 34 have been released, and the movable contact 26 positioned in the open position, the biasin~ spring 178 returns the toggle lever 94 to its position wherein the surface 182 is resting upon the D-latch 172. To prevent the toggle lever 94 from moving too far in the clockwise direction, the stop pin 180 is utilized to stop the toggle lever 94 at its correct location. The mechanical advantage in this release system occurs because of the very slight clockwise rotation of the D-latch 172 which releases the toggle lever 94 as compared to the larger rotation of the latch release lever 168.
As can be seen in Figure 3, the D-latches 170 and 158 are attached to two l.evers each. ~evers 183 and 190 are secured to D-latch 158, and levers 168 and 192 are secured to D-latch 170. The extra levers 190 and 192, are present to permit electromechanical or remote tripping o~ the breaker and spring discharge. An electromechanical flux transfer shunt trip 193 (see F'igure 3) may be secured to the ~rame 194 and connected to the current trans~ormer 38 so that, upon the occurrence of an overcurrent condition, the flux transfer shunt trip 193 will move lever 192 in the clockwise direction to provide release of the toggle lever 94 and opening of the contacts 24. An electrical solenoid device 3 may be positioned on the frame 19~ ad,acent to lever 190 so --~ I _ ~1~46~V 46,792 that the remote pushing of a switch (not shown) will cause rotation of lever 190 causing rotation of D-latch 158 and discharging of the spring 148 to thereby close the breaker.
Accordingly, the device of the present invention achieves certain new and novel advantages resulting in a compact and more efficient circuit breaker. A dual drive means capability is provided wherein a handle can be uti-lized for manual operation to turn the drive shaft, and where a motor operator is capable of engaging the drive shaft to provide rotation thereof. The motor operator can be plugged into the drive shaft without dismantling the circuit breaker.

Claims (5)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A circuit breaker comprising:
a stationary contact;
a movable contact operable between open and closed positions with respect to said stationary contact, said mov-able contact being biased in the open position;
a movable contact holder, said movable contact being held by said contact holder;
toggle means engaging said contact holder for moving said movable contact between said open and closed positions, said toggle means comprising first and second links and a toggle lever, said first link operationally engaging said contact holder, said second link being pivotally connected to said first link, said toggle lever being pivot-ally connected to said second link, said second link having a drive pin fixedly secured thereto;
a rotatable drive shaft having an end thereto, said drive shaft having a cam secured thereto, said cam being rotatable with said drive shaft;
a drive handle secured to said drive shaft capable of rotating said drive shaft;
a motor operator including a rotatable output shaft capable of engaging said drive shaft end to impart rotation to said drive shaft;
a rotatable follower plate having a cam roller secured thereto, said follower plate having a drive pawl pivotally secured thereto, said cam roller engaging said cam, said drive pawl being disposed adjacent said drive pin;
spring means pivotally connected to said follower plate and capable of being in spring charged and spring dis-charged positions, said spring means being charged by the rotation of said cam causing said cam roller engaged therewith to move outwardly causing rotation of said follower plate causing charging of said spring means, the changing of posi-tion of said spring means from charged to discharged causing rotation of said follower plate such that said drive pawl is capable of engaging said drive pin to move said toggle means into a toggle position, the movement of said toggle means into toggle position causing movement of said contact holder which moves said movable contact into closed position;
releasable toggle latch means for holding said toggle means in toggle position; and releasable drive latch means for holding said fol-lower plate in the spring charged position.

2. The circuit breaker according to claim 1 wherein said motor operator output shaft has an end thereof having a pair of parallel, spaced-apart fingers extending therefrom;
said drive shaft end has a tongue extending out-wardly therefrom; and said drive shaft tongue is disposed intermediate said output shaft fingers, said output shaft fingers engaging opposite sides of said tongue.

3. The circuit breaker according to claim 1 wherein said drive shaft end has a pair of openings therein;
said motor operator output shaft has an end thereof having a pair of pins extending outwardly therefrom;
and said motor operator output shaft pins are disposed within said drive shaft end opening.

4. The circuit breaker according to claim 1 wherein said motor operator output shaft has an end thereof having a pair of openings;
said drive shaft end has a pair of pins extending outwardly therefrom; and said drive shaft end pins are disposed within said motor operator output shaft openings.

5. The circuit breaker according to claim 1 wherein said motor operator comprises:
a motor having a shaft; and a pair of cooperating gears, said motor shaft being secured to one of said gears;
said motor operator output shaft being secured to the other of said gears.