US1368003A - Automatic electric-circuit breaker - Google Patents

Description

l+, E. WADSWORTH AND W. B. ENSIGN.

AUTOMATIC ELECTRIC CIRCUIT BREAKER.

APPLICATION FILED FEB. I6. 1920.

H. E. WADSWORTH AND W. B. ENSIGN.

AUTOMATIC ELECTRIC CIRCUIT BREAKER.

. APPLICATION FILED FEB. I6. I920. 1,368,003.

Patented Feb. 8,1921.

2 SHEETS-SIIEET 2.

uurrso STATES PATENT OFFICE.

HARRY E. WADSWORTH, OF NEW YORK, AND WILLIAM B. ENSIGN, OF WHITE PLAINS,

NEW YORK.

AUTOMATIC ELECTRIC-CIRCUIT BREAKER.

Specification of Letters ratent.

Patented Feb. 8, 1921.

To all whom it may concern:

Be it known that we, HARRY E. WADS- WORTH, a citizen of the United States, and a resident of the borough and county of Bronx, city and State of New York, and WILLIAM B. ENsIGN, a citizen of the United States, and a resident of White Plains, count of Westchester, and State of New York, ave invented certain new and useful Improvements in Automatic Electric-Circuit Breakers, of which the following is a specification.

Our improvements relate to means for automatically breaking or opening an electric circuit when a predetermined excess of current occurs, substantially as set forth in our concurrent application Serial No. 314,- 552, filed July 31, 1919, the object, as in that case, being primarily to dispense with cut-out fuses by providing an equivalent therefor to be positioned in like manner between the usual spring clip terminals; to effectually protect the operative parts and prevent tampering therewith, etc.,0ur invention in the present case consisting in the construction, combination and arrangement of parts herein described and claimed specifically, whereby these desired results are attained; and distinctive features in the present case being the duplex trip break and re-set mechanism, and the employment of a solenoid (hammer) plunger to effect an instantaneous break of circuit whenever the strength of the electric current exceeds a rescribed degree of intensity, all as hereinafter fully set forth.

In the accompanying drawings,

Figure 1, is a front elevation of our improved circuit breaker;

Fig. 2, is an end elevation thereof;

Fig. 3, is a front view of our circuit breaker as mounted between knife blade circuit terminals;

Fig. 6, is a like view unto Fig. 4, illustratingwthe re-set of the operative parts;

ig. 7, is a section taken upon plane of line 7--7, Fig. 4;

Fig. 8, is a section taken upon plane of line 8-8, Fig 4;

Fig. 9, is a detail view, upon a larger scale, showing the pivotal connection between the upper ends of the blade contact levers, ac-

tuating springs, etc.;

F g 9 is an enlarged detail of Fig. 9;

Fig. 10, 1s a sectional detail taken upon plane of line 10l0, Fig. 9;

Fig. 11, 1s a detail view of one of the latch lever springs;

Flg. 12, 1s a diagrammatic representation of the electric contacts incidental to our device.

Fig. 13, is a transverse section taken upon plane of line 13-13, Fig. 4. The casing of insulating material is made in two parts U, 0, each forming one half of the basic structure, and each being substantially a reversed duplication of the other. The extremities of each half aresemi-circular, so that when the halves are fitted to gether cylindrical ends are formed over which the cylindrical metallic ferrule caps F, F, fit, binding the two said non-conductive parts (J, U, of the housing together. These parts U, C, are further secured together by the rigidly mounted cross rods 0, c, and further, if desired, by screws or bolts for which holes 0, 0, may be provided as indicated in Figs. 4, 5 and 6.

Each ferrule cap F, F, is slidable within certain prescribed limits, on its end of the casing for the purpose of re-setting the other operative parts, as hereinafter set forth, after a break in the electric circuit,-stops 1', r, being provided to limit the outward movement of said ferrules. These ferrule caps may be adapted, when in closed normal position on the cylindrical ends of the casing, for insertion between either spring terminal clips as indicated in Fig. 2, or for engagement with knife blade circuit terminals, as in Fig. 3, in which latter view the device is shown as adapted to either form of terminal connection.

The medial portions of the halves C, C, of the non-conductive casing are formed with coincidental lateral extensions 0*, and are recessed to afford operative space-for the movable parts of the switch control mechanism.

S, is a solenoid coil fixedly mounted upon and between the lateral extensions (3*, C, of the casing C, C, the opposite ends .9, s, of the coil 8, of which are connected with fixed contact plates 8*, e embedded respectively in the cylindrical extremities of the casing as shown more particularly in Figs. 7 and 8. fly, are contact plates affixed to the ferrules F, respectively, and movable therewith, and in parallel relation to the aforesaid fixed contact plates 8*, 8*. l0, 7:, are knife blade switch plates movable be tween, and adapted to contact with said fixed contact plates s, 8*, and said movable contact plates 7', f. One of the knife blade switch plates, Ir, is pivotally connected with the toggle lever 2 and the other A1, with the toggle lever 6, both of which toggle levers t, t, are pivotally supported on the fulcrum bar Z), rigidly attached to, and positioned between, the halves C, C, of the casing, as shown more particularly in Fig. 7.

Z, Z, are latch levers fulcrumed on the cross rods 0, c, and controlled by spring: 0*, 0*, which tend constantly to hold their adjacent inner ends in contactual engagement with studs 3), p, protuberant from opposite sides of a trip-plunger P. The latter straddles the fulcrum bar Z), being formed with a slot 79', for this purpose. Normally, when the operative parts are in circuit-closed relationship as in Figs. 4 and 6, one end wall of the slot 3), rests against the fulcrum bar Z), (as shown in Fig. 9, Fig. 9) which thus acts as a stop to the thrust of the latch lever springs 0*, 0",said slot p, being of a length to allow the trip plunger P, longitudinal movement in the opposite direction sufficient to cause it to rock the latch levers Z, Z, against the resistance of their springs 0*, c", to release the outer ends of said latch levers Z, Z, from the shoulders 6 25*, on the free ends of the toggle levers t, t, as shown in Fig. 5, when said trip-plunger P, is actuated by the solenoid hammer core h, as happens whenever the electric current passing through the solenoid coil 8, exceeds a prescribed degree of intensity. This tripping operation is illustrated in Fig. 5, which also shows the toggle levers Z, Z, as collapsed inward centrally toward each other under the pressure of the springs t t affixed to the cross bar Z), and having their free ends bearing upon said toggle levers t, t, as shown more particularly in Figs. 9 and 10, of the drawings. This collapse of the toggle levers Z, Z, of course withdraws the knife blade switch plates Z0, is, from contactual engagement with both the fixed contact plates 8*, 8*, and the movable contact plates 7, f, thereby opening the electric circuit, whereupon the solenoid hainmer core h, is immediately demagnetized and returned by its retractile spring h, to its normal position, as in Figs. 4 and 6.

To reinsert the knife blade switch plates 7c, is, between the fixed contact plates 8X, 8*, and the movable contact plates 7, f, and

pea

thus again close the electric circuit the ferrules F, F, after removal from the main circuit terminals are slid outward on the cylindrical ends of the casing as shown in Fig. (i, causing the stop shoulders r, on the inner ends of the slides r, '1", (which are attached to said ferrules) to return the toggle levers If, t, to normal extended position, when the latch levers Z, Z, automatically re-lock said toggle lovers 1%, t, with their knife blade contact plates 8*, s, again in closed contactual relationship with the aforesaid fixed and movable contact plates, as shown particularly in Fig. 8.

The retractile spring 7L, interposed between the solenoid hammer core 7L, and the end of the trip plunger P, while sufficient in strength to effect the return of the hammer core h, to normal position when demagnetized by the opening of the electric circuit, and to retain it therein so long as the current passing through the solenoid coil 8, is normal, is insuflicient in resistive strength to prevent the hammer-core from impinging suddenly and forcefully against the end of the trip plunger P, whenever an abnormal intensity of current seeks to pass through said solenoid coil, so that the break of circuit is practically instantaneous. As a re sult the electric circuit is opened with a minimum of sparking and heat generation incidental to contact severance,the intensity thereof being sub-divided between the two knife blade switch plates Zr, 7;, and their respective movable and fixed contact plates. h is a set screw for regulating the available thrust of the solenoid hammer core It, as related to the trip plunger P.

As in.tl1e case of our cut-out slide circuit breaker described in said concurrent application Serial No. 314,552, it will be seen that in our present device the switch latch may be reset, when the device is removed from between the terminal clips, without opening the casing, and by the simple expedient of reciprocating portions thereof.

Furthermore all the operative parts of the circuit breaker are inclosed, isolated, and protected from contact with extraneous objects: and they cannot be tampered with or improperly manipulated while the incasement is intact. The device is an effectual substitute for. the blow-out fuse, with the great advantage that it can be reset and used indefinitely; and the" act of re-setting simply involves its removal from between the circuit terminal clips and the manipulation of the ferrule caps F, F, after which it is ready for replacement in operative position.

By the term electric circuit terminal spring clips as used herein we mean either the knife blade terminals shown in Fig. 3, or the clasps shown in Fig. 2.

\Vhat we claim as our invention and desire to secure by Letters Patent is,

1. An automatic electric circuit breaker of the character designated, comprising a casing of insulating material, metallic ferrule caps formed externally for contactual engagement with main electric circuit terminal spring clips, fixed contact plates, one in each cylindrical extremity of the casing, a solenoid the coil ends of which are connected with said fixed contact plates, movable contact plates, one attached to each ferrule in parallelism with the aforesaid fixed contact plates, knife blade switch plates movable between and adapted to contact with said fixed and said movable ferrule contact plates, toggle levers pivotally connected with said knife blade switch plates and with a trip plunger, said trip plunger, spring latch levers contacting with said trip plunger and adapted to engage with shoulders on said toggle levers, and a solenoid hammer-core adapted to actuate said trip plunger, for the purpose described.

2. An automatic electric circuit breaker of the character designated, comprising a casing of insulating material, metallic ferrule caps formed externally for contactual engagement with main electric circuit terminal spring clips, fixed contact plates, one in each cylindrical extremity of the casing, a solenoid the coil ends of which are connected with said fixed contact plates, movable contact plates, one attached to each ferrule in parallelism with the aforesaid fixed contact plates, knife blade switch plates movable between and adapted to contact with said fixed and said movable ferrule contact plates, toggle levers pivotally connected with said knife blade switch plates and with a trip ed to actuate said trip plunger, said trip plunger, spring latch levers contacting with said trip plunger and adapted to engage with shoulders on said toggle levers, a solenoid hammer core adapted to actuate said trip plunger, and a re tractile spring interposed between said trip plunger and said solenoid hammer core, for the purpose described.

3. An automatic electric circuit breaker of the character designated, comprising a casing of insulating material, metallic ferrule caps formed externally for contactual engagement with main electric circuit terminal spring clips, fixed contact plates, one in each cylindrical extremity of the casing, a solenoid the coil ends of which are connected with said fixed contact plates, movable contact plates, one attached to each ferrule in parallelism with the aforesaid fixed contact plates, knife blade switch plates movable between and adapted to contact with said fixed and said movable ferrule contact plates, toggle levers pivotally connected with said knife blade switch plates and with a trip plunger, said trip plunger spring latch levers contacting with said trip plunger and adapted to engage with shoulders on said toggle levers, a solenoid hammer core adaptplunger, a retractile spring interposed between said trip plunger and said solenoid hammer core, and means for adjusting the available thrust of said solenoid hammer core as related to the said trip plunger, for the purpose described.

HARRY E. WADSWORTH. WILLIAM B. ENSIGN.

Witnesses:

Gno. WM. MIATT, L. H. BRADLEY.

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