US3329912A - Multipole circuit breaker with interconnected toggle locks and contact members - Google Patents

Description

3,329,912- ECTED J ly 1967 L. w. BRACKETT MULTIPOLE CIRCUIT BREAKER WITH INTERCONN TOGGLE LOCKS AND CONTACT MEMBERS 5 Sheets-Sheet 1 Filed Oct. 1, 1965 mvamoa jaw/ream? Wflraz'itett y 1967 1.. w. BRACKETT 3,329,912

MULTIPOLE CIRCUIT BREAKER WITH INTERCONNECTED TOGGLE LOCKS AND CONTACT MEMBERS Filed OGC. l, 1965 3 Sheets-Sheet 2 July 4, 1967 L. w. BRACKETT 3,329,912

MULTIPOLE CIRCUIT BREAKER WITH INTERCONNECTED TOGGLB LOCKS AND CONTACT MEMBERS Filed Oct. 1, 1965 3 Sheets-Sheet 3 United States Patent 3,329,912 MULTIPOLE CIRCUIT BREAKER WITH IN- TERCONNECTED TOGGLE LOCKS AND CONTACT MEMBERS Lawrence W. Brackett, Georgetown, Mass., assignor to Wood Electric Corporation, Lynn, Mass, a corporation of Massachusetts Filed Oct. 1, 1965, Ser. No. 491,986 12 Claims. (Cl. 335-8) The field of the present invention is that of multipole circuit breakers of the so-called trip free type, which after automatically opening caused by a faulty circuit condition cannot be reclosed so long as the fault exists.

Objects of the invention are to provide multipole circuit breaker units of the above type which utilize single circuit breakers of conventional construction with only minor modification; to provide for the linked assembly of single breakers in a partitioned housing with minimal partition discontinuity; to provide multipole circuit breakers wherein single breakers are correlated for tripping the entire unit form any one single breaker but each being moved by its own driving power; to provide such breakers wherein an emergency unlatching and circuit opening component of any one single breaker affects the corresponding component of each other breaker without the intervention of other components of the single breaker; to provide circuit breakers for any desirable number of poles by relating single circuit breakers with a single rotating link of reliable rigid construction; to provide multipole circuit breaker units composed of standard single breakers which are linked by a single optimally simple mass production molded connector, which units can be very easily assembled and do not require appreciable modification of the basic single breaker movement construction; and to provide a multipole trip free circuit breaker which is simple, comparatively inexpensive in manufacture and assembly, and rugged and reliable in operation.

The substance of the invention can be shortly stated as follows.

Known circuit breaker mechanisms contain releasable locking mechanism such as the latches of conventional toggle movements which normally hold the toggle linkage in spread position but are opened to collapse the toggle for breaking circuit, when a catch element is displaced, such as rotated, by an element of the breakers safety device which detects or responds to an abnormal condition such as overcurrent. According to the-present invention, the releasing motion of the locking element of one single breaker is transferred by way of a contact component to the corresponding locking elements of one or more additional breakers by release transfer means such as a trigger link pivoted on partitions or walls of the housing and capable of operating the lock release of each single breaker.

In the herein described typical and preferred embodiment, the locking means has a toggle latch and a lock releasing catch head rotatable on a toggle link either directly by the safety device or by a trigger finger extending from the catch head. The release transfer means is a rotatable trigger link with a number of trigger arms (corresponding to the number of single breakers) extending laterally from a trigger stem and engageable' with a movable contact member (or component associated therewith) of a respective single breaker as well as with the trigger finger of the respective catch element. With the breakers closed, the trigger arms are in neutral position between breaker contacts and trigger fingers. In a preferred embodiment, this neutral position is maintained by means of stop and spring means associated with the trigger link and a housing wall. When any one of the 3,329,912 Patented July 4, 1967 ice single breakers opens, its movable contact is forced against its trigger arm, rotating the trigger stem and with it all other trigger arms, each of which now hits its trigger finger, rotates its catch head, and thus unlocks the toggles of the other breaker or breakers.

According to an important practical aspect of the invention, each trigger arm extends to one side only into a space between the movable contact and the trigger finger of the respective breaker, touching neither with the breakers closed, so that the trigger link acquires considerable inertia upon being hit by one movable contact which impact is rapidly transferred to all trigger fingers which rapidly operate the other single breakers. The inertial blow originating in the spring forces of the breaker movement enhances the transfer from one breaker to another.

In another practical aspect, the pivot structure for the trigger link is formed by windows of partition walls which can be divided to permit easy assembly.

In a preferred embodiment the trigger arms are formed in two adjoining halves of unequal lengths and face inclinations to provide optimal positions of leverage with respect to contact members and trigger fingers.

The description refers to drawings wherein:-

FIG. 1 is an isometric view of a triple pole breaker according to the invention;

FIGS. 2, 2a, and 2b are similar longitudinal sections near a wall of the housing such as on lines 22 of FIG. 4, showing in elevation a single breaker in three different significant positions, namely closed, trip free opened, and manually opened;

FIG. 2c is a section similar to FIG. 2, but only of a portion near an end of the trigger link;

FIGS. 3 and 3a are fragmentary elevations of the tog gle lock in latched and unlatched conditions, respec tively;

FIG. .4 is a section on 44 of FIG. 2;

FIG. 4a is a section similar to FIG. 4 but only of a portion incorporating a modification thereof involving an end wall portion;

FIG. 5 is a view from the right-hand side of FIG. 4, with the single breakers and one-half of the housing removed; and

FIG. 6 is an isometric view of the trigger link with one movable switch contact and one toggle yoke with trigger finger.

FIG. 1 shows the exterior of a three-pole circuit breaker according to the invention, but it should be understood that its principles are applicable to two-pole breakers as well as to breakers with more than three poles. A conventional insulating housing 10 encloses three single breakers, each with a handle such as 11.1, 11.2 and 11.3. The handles are connected for joint operation by a bar 12 which is also shown in FIG. 2. The housing is conveniently divided into two halves 10.1 and 10.2. FIGS. 1, 2 and 4 also show the terminal screws 14.1 to 14.6, two for each single breaker, which here also serve for holding the fixed breaker contact 37 and the movement and magnet support 30. As especially :shown in FIGS. 4 and 5, the housing has two partitions 15, 16 which are split similarly to the housing proper as shown at 15.1, 15.2 and 16.1, 16.2. The partition halves 15.1 and 16.1 have cut-outs such as indicated at 111 which together with 15.2 and 16.2 form semicircular openings for pivoting the trigger spindle of the link which will be described below.

In the following description, the complete rnultipole circuit breaker will be referred to for short as breaker unit or unit, whereas each individual single pole switch will be referred to as single breaker or simply breaker. The two or more breakers or a unit are or at least can be of identical construction, their inter-relation being accomplished by elements whose configuration is essentially independent of the construction, whether or not conventional, of each breaker. The individual breakers will now be described by describing one of them, here by way of example the intermediate one between partitions 15, 16 as indicated :by the section line in FIG. 4, with reference to FIGS. 2 to 3a.

The breaker movement to be described is of conventiona-l construction such as for example dealt with in Patent No. 2,360,922 of Oct. 24, 1944 to K. W. Wilckens. It will be understood that deviations from and improvements of this conventional construction, involving progress in fabrication as well as performance can be applied, and have been applied to the present basic construction; such improvements however are not part of the present invention which relies generally on the correlation of movable switch components and breaker unlocking components, regardless of the peculiar construction of such components.

The breaker movement is supported by a toggle frame 20 which has (left-hand side of FIG. 2) two parallel switch blade ears 21 leading into a common bridge 22. On the other side of the frame 20 are two parallel armature and handle supporting ears 23. Each of these has a handle pivot extension 24 and a tightening sector 25 for the armature spring 42.1. The toggle frame 20 is carried on an armature with a coil form 31. The magnet structure 32 is supported by means of its coil tail 33 on the terminal bar 34 which is fastened to the housing with terminal screw 14.5. The fixed contact 37 is similarly fastened to the housing at 14.2.

An =armature'40 is pivoted by means of two ears 41 (behind the cars 23) on a pintle 42 fastened to the frame ears 23. The L-shaped armature has an anchor 45 and an actuator 46-.

The switch 50 has the above-mentioned fixed contact 37 and a movable switch blade 52 which is pivoted at 53 on a round pintle in a pair of oblong perforations of the frame switch ears 21. A spring 54 is wound around a pin 55 in a second pair of perforations of the frame ears 21 and biases the switch blade 52 into open position, compare FIGS. 2a and 2b.

The handle hub is pivoted on a pintle 61 inserted into opposed perforations of the ears 24 on the frame. On the other side of the grip 11, 12 (FIG. 1) are two toggle link engaging ears 63 for a toggle pintle 65.

The toggle movement proper to a blade link 71 with two walls 71.5, 71.6 connected by a bridge 71.7 and a handle link 72. The blade link is pivotally joined to the blade 52 with a pintle 71.1 which carries an assist spring 71.2 that enhances the effect of contact main spring 54. The handle link 72 is pivoted to the blade link with a toggle pintle at 71.2, and to the handle at '65. The toggle pintle 71.2 carries a toggle spring 72.3.

The toggle trigger mechanism which is also shown in FIGS. 3 and 3a is arranged within the two walls 71.5 and 71.6 (FIG. 3) of the blade link 71. Each of these walls has four perforations, two each for the switch blade pivot 71.1 and the toggle pivot 71.2 respectively, and two each, indicated at 81 and 82 (FIG. 3) for the trigger crank yoke 85 that is completely shown also in FIG. 6. The latch tooth 76 of the handle link 72 extends between the two walls of the switch blade link 71. The trigger yoke 85 (FIG. 6) has a yoke stem 85.1, a crank arm 85.3 and catch head 85.5 with a flat 85.6. A spring 87, wound on part of head 85.5, tends to keep the yoke 85 in the position of FIG. 3. With the switch in closed position and switch parts 37, 52 contacting, the latch tooth 76 of the handle link 72 is outside of the fiat 85.6 and engages the full or convex region of the head 85.5, as shown in FIG. 3. The toggle is then firmly locked in the position of FIG. 2. The diameter of perforation 81 is larger than that of the stern 85.1 which can swing in that perforation whereas the head 85.5 fits its pivot perforation 82. When the actuator 46 of the armature 40 turns in the direction of arrow a, due to attraction of the anchor 45 by the core of coil 32, it touches the crank arm 95.3, rotates it in the same direction and with it the head 85.5- and its flat 85.6. The tooth 76 can now enter the fiat and the above mentioned rigid locking connection of the two links 71 and 72 is opened, as shown in FIG. 3a. The stem 85.1 rotates on the head 85.5, moving within perforation 81. When the toggle linkage collapses, the main and auxiliary biasing springs 54 and 71.2 quickly break contact at 50.

If it is attempted to close the circuit by turning handle 11 to closed position as in FIG. 2, after the toggle linkage is triggered by a persisting abnormal condition and opened into the condition of FIG. 2a, the two links 71 and 72 will merely rotate relatively to each other; the contacts will remain open and the handle will move back into open position as in FIG. 2b. This is commonly referred to as trip free operation.

For manually breaking contact, the handle 11 is rotated downwardly as shown in FIG. 2b, and this moves the two links 71 and 72, which remain rigidly joined, towards the right thus moving contact '52 in the same direction.

It will be observed from FIGS. 2 to 2a that the trigger lock at tooth 76 and fiat 85.6 is loosened by rotating the catch head 85.5. This releasing rotation can be brought about in various ways such as, in a single breaker, by the armature actuator 46 or by special provisions according to the invention which will now be described.

Referring to FIGS 2 to 6, the above-described conventional toggle lock mechanism or analogous mechanism having a similar function carries lock releasing trigger means, here a trigger finger which extends, laterally between the catch head 85.5 and the crank arm 85.3, far enough to be engageable by an arm of the trigger link described below. It will be evident that the addition of this trigger finger or similar structure to a conventional lock structure involves a minimal amount of material and work. The finger 105 can be stamped from suitable metal and welded or soldered to the yoke 85.3, 85.5, or the complete component can be preformed.

The trigger link according to the invention, numbered 101, has a stem 102 from which extend two or more trigger arms 106, engageable with the above-described trigger fingers 105 of the individual breakers. In the present embodiment the trigger arm has two sections of different lengths numbered 106.1 and 106.2 which are axially separated. Section 106.1 contacts the finger 105 while the shorter section 106.2 can be reached by the switch contact member 52. A stop 108 extends from the stem 102 towards the circuit breaker housing and has a face 108.1 which engages the housing when the breaker is closed as for example shown in FIG. 2. A spring 109 (FIGS. 4, 5 and 6) tends to rotate the trigger arm 106 into this position (FIG. 2) which is desirable in order to hold the arm between switch contact 52 and trigger finger 105 without touching either. The trigger stem 102 is pivoted in the partitions 15.1 and 16.1 by means of the cut-outs 111 shown in FIGS. 2 and 20. These cut-outs are closed by the edges of the partitions 15.2, 16.2, as shown in FIGS. 2c and 4. For double breakers with only one partition, the trigger arm stern 102 is preferably supported in two pivot recesses, such as indicated for one end of the stem in FIG. 4a, where 10.1 and 10.2 are the divided side walls, 115 is a boss of the housing half 10.1 and 116 is the above-mentioned recess. In this instance the intermediate partition has an opening which does not have to fit the trigger stern 102. If the stem is pivoted in the partition such as shown in FIGS. 4 and 5, a fit suited for that purpose has to be provided in these partitions such as 15.1 and 16.1.

The operation of the above-described multipole circuit breaker unit will now be explained, particularly with reference to FIGS. 2 to 3:1 and 6. For purposes of this explanation it is important to distinguish between a single breaker movement which is actually tripped by its magnet or equivalent safety device on the one hand, and on the other hand the single movement or movements which break circuit, not on initiation by their own respective safety device, but by way of mechanical initiation from another actually tripped single breaker.

Assuming that the circuit breaker unit is in normally closed position such as shown in FIG. 2, the trigger arms 106.1, 106.2 will be free from contact members 52 as well as trigger fingers 105, and retained in that position by the spring 109 pressing the stop face 108.1 against the housing as described above with reference to FIG. 2.

For opening the circuit breaker, the handle 11, 12 is swung into the position of FIG. 2b. This opens the contacts by means of the locked toggle linkage with tooth 76 engaged by head 85.5 as shown in FIG. 3. The trigger link is held With its arms 106 between switch contacts 52 and trigger fingers 105, with the stop face 108.1 swung out against the force of spring 109, as shown in FIG. 211.

It may now be assumed that some abnormal condition trips a single magnet or other emergency responsive device that is incorporated in the circuit breaker. In the present embodiment the magnet attracts its armature and the actuator 46 turns clockwise in the direction of arrow a (FIG. 3). The crank arm 85.3 is contacted by the actuator and rotates with the catch head 85.5 as above described. The toggle mechanism of this single circuit breaker is thus unlocked and its contact 52 separates from the fixed contact 37, swinging in clockwise direction with reference to FIG. 2. Referring especially also to FIG. 6, it will be seen that the movable contact 52 now strikes the shorter section 106.2 of the trigger arm 106 and rotates the entire trigger link 101 in counterclockwise direction (arrow b of FIG. 6), against the force of spring 109. The longer arms 106.1 then strike the respective trigger fingers 105 of the breakers which remained closed, and these turn their catch heads 85.5, unlocking the respective toggles so that the respective single breakers now also open. It will be evident that this holds for double pole breakers as well as the triple breaker herein described, and indeed for multipole devices with any number of breakers, each of which is then equipped with a trigger finger corresponding to 105 of FIG. 6 and aligned with the appropriate number of arms 106 of a trigger link extending alongside all breakers.

With the handle still forced into closed position, the circuit breaker is in the trip free position shown in FIG. 2a. Upon releasing the handle, the latter will be moved by the switch springs into the open position of FIG. 2b. So long as any one or more emergency actuators (such as 46) are in abnormal unlocking position, forcible operation of the handle in an attempt to close the breaker will be similarly ineffective, that is, moving the handle into closed position will not close the breakers and the handle will move back to open position.

The two trigger link arms 106.1 and 106.2 are of different shapes in order to accommodate the conventional circuit breaker construction and to fit the trigger finger 105 which is added to each toggle lock. It will be understood that the configurations of both trigger arms and fingers, can and will be modified within the concept of the invention in order to accommodate switch contact and movement constructions which deviate from those herein described by way of example.

The relative positions of the interacting emergency release actuators (such as 46), lock releases (85, 105), trigger link elements (101, 102, 106) and switch components (52) are designed also with a view to provide selected leverages, and distances between 'these parts, in order to introduce inertial impacts where beneficial for quick and forceful operation, and to avoid them where undesirable. In this context it will be observed that the present trigger arms operate in parallel so that there is no delay between the induced triggering operations as is the case of serially operated triggers where these operations might progress from one end to the other of the movement train.

With regard to the materials used for purposes of the invention, the fingers are at this time preferably made from steel, and welded to the conventional toggle trigger yoke. The trigger link 101 with arms 106 and stop 108 is made of hard synthetic material, now preferably a phenolic resin.

I claim:

1. A multipole circuit breaker unit having within a housing two or more single pole breakers each having movable contact means and a movement including locking means for holding the movement in circuit making position or normal circuit breaking position and for opening it to break circuit in response to detecting means operative to release the locking means in response to an abnorrnal condition, characterized by:

release means extending from each of said locking means for unlocking by movement thereof, the locking means to break circuit; and

response transfer means movably mounted on said housing and having, for each single breaker, linked arm means engageable with the respective movable contact means and with the release means of the respective locking means, to cause said unlocking movement of all circuit making single breakers when engaged by the movable contact of any one single breaker upon opening thereof by said detecting means.

2. The circuit breaker unit according to claim 1 wherein said response transfer means includes a unitary rotary trigger link pivoted on said housing, with its arm means extending into the paths of corresponding movable contact means and release means.

3. The circuit breaker unit according to claim 1 wherein said locking means respond to rotary motion and wherein said release means includes rotatable trigger fingers extending into the path of corresponding arm means.

4. The circuit breaker unit according to claim 2, wherein said locking means respond to rotary motion, wherein said release means includes rotatable trigger fingers extending into the path of corresponding arm means, and wherein the trigger finger and the contact means of each single breaker extend on opposite sides of and distanced from the respective trigger arm means of the breaker, for contacting with inertial impact.

5. The circuit breaker un-it according to claim 3, including spring means tending to rotate said arm means of the trigger link toward the contact means, and a stop extension of the link urged by the spring to contact the housing and to retain the arm means distanced from the contact means of a closed breaker.

6. The circuit breaker unit according to claim 5 wherein said arm means are accommodated, with the breakers closed, between said contact means and said fingers, with said stop extension out of contact with the housing against the tension of said spring means.

7. The circuit breaker unit according to claim 3 wherein each one of said arm means has a longer half cooperating with a respective trigger finger and a shorter half coopcrating with a respective contact means.

8. A multipole circuit breaker unit of the type having Within a partitioned housing two or more single pole breakers in compartments between the housing walls and one or more partitions, each breaker having a swinging contact actuated by a toggle movement including rotary locking means for holding the contact in circuit making position or normal circuit breaking position and for releasing the contact to break circuit in response to overcurrent responsive means operative to rotate said locking means, comprising:

trigger fingers, one extending from each of said locking means parallel to each other for swinging in parallel to the contacts thereby to release the locking means; and

a unitary trigger link pivoted on said housing and having a stern and having for each single breaker in a respective partition arm means engageable with one of said contacts on one side and with the trigger finger of the respective locking means on the other side, for rotating its trigger finger to unlock its toggle movement and to open its contact when moved by the contact towards the finger.

9, The circuit breaker unit according to claim 8 wherein the housing has several partitions, at least two with a pivot perforation for supporting said stem.

10. The circuit breaker unit according to claim 8 wherein a partition has a perforation for said stern and two opposite wall portions have pivot means for opposite ends of said stem.

11. The circuit breaker unit according to claim 9, wherein a partition has a perforation for said stern and two 3 opposite wall portions have pivot means for opposite ends of said stem, and wherein said housing and said partitions are divided and said perforations are formed by a notch in the face of one portion half and the edge of the opposite portion half.

12. The circuit breaker unit according to claim 8 whereing said trigger fingers and said contacts extend in the same general direction, wherein the fingers are shorter than the contacts, and wherein said arm means have a short segment for engaging the contact and a long segment for engaging the finger.

References Cited UNITED STATES PATENTS 3,098,912 7/1963 Sprague 335-9 BERNARD A. GILHEANY, Primary Examiner.

R. N. ENVALL, 111., Assistant Examiner.

Claims (1)

1. A MULTIPOLE CIRCUIT BREAKER UNIT HAVING WITHIN A HOUSING TWO OR MORE SINGLE POLE BREAKERS EACH HAVING MOVABLE CONTACT MEANS AND A MOVEMENT INCLUDING LOCKING MEANS FOR HOLDING THE MOVEMENT IN CIRCUIT MAKING POSITION OR NORMAL CIRCUIT BREAKING POSITION AND FOR OPENING IT TO BREAK CIRCUIT IN RESPONSE TO DETECTING MEANS OPERATIVE TO RELEASE THE LOCKING MEANS IN RESPONSE TO AN ABNORMAL CONDITION, CHARACTERIZED BY: RELEASE MEANS EXTENDING FROM EACH OF SAID LOCKING MEANS FOR UNLOCKING BY MOVEMENT THEREOF, THE LOCKING MEANS TO BREAK CIRCUIT; AND RESPONSE TRANSFER MEANS MOVABLY MOUNTED ON SAID HOUSING AND HAVING, FOR EACH SINGLE BREAKER, LINKED ARM MEANS ENGAGEABLE WITH THE RESPECTIVE MOVABLE CONTACT MEANS AND WITH THE RELEASE MEANS OF THE RESPECTIVE LOCKING MEANS, TO CAUSE SAID UNLOCKING MOVEMENT OF ALL CIRCUIT MAKING SINGLE BREAKERS WHEN ENGAGED BY THE MOVABLE CONTACT OF ANY ONE SINGLE BREAKER UPON OPENING THEREOF BY SAID DETECTING MEANS.

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