US3193647A

US3193647A - Circuit breaker with trip-indicating handle

Info

Publication number: US3193647A
Application number: US233575A
Authority: US
Inventors: Norman R Beaudoin; Jr Benjamin A Piteo
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1962-10-29
Filing date: 1962-10-29
Publication date: 1965-07-06
Anticipated expiration: 1982-07-06

Description

y 6, 1965 N. R. BEAUDOIN ETAL 3,193,647

CIRCUIT BREAKER WITH TRIP-INDICATING HANDLE Filed Oct. 29, 1962 2 Sheets-Sheet 1 F/GZ.

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CIRCUIT BREAKER'WITH TRIP-INDIGATING HANDLE Filed Oct. 29; 1962 2 Sheets-Sheet 2 /NVEN7'0RS.' 55mm Ml/V A. P/ 7'50, J52, NORMA/v R 654 (mo/xv,

United States Patent 3,193,647 QERCUET BREAKER WlTH TRIP-INDIQATING HANDLE Norman R. Beandoin, Southington, and Beniamin A.

Fiteo, Jr., Forestviile, Conn, assignors to General Electric Company, a corporation of New York Filed Oct. 29, 1962, Ser. No. 233,575 6 (Iiaims. (Cl. 260-416) Our invention relates to electric circuit breakers and more particularly to circuit breakers of the type which are adapted for use in the control of branch power and lighting circuits, such as used in residential applications.

Circuit breakers provided in accordance with the prior art for such applications, have ordinarily been relatively complicated and expensive, due primarily to the necessity of meeting a number of specific requirements of electrical inspecting authorities and Underwriters Labora tories. While attempts have been made to provide residential type circuit breakers of simplified construction, such simplification has usually been achieved only at the sacrifice of one or more operational features, such as trip indication, or ordinary switching function.

Application Serial Number 236,165 filed November 7, 1962, now Patent No. 3,171,919, Herman I. Hammerly, assigned to the same assignee as the present invention, for example, discloses a simplified residential type circuit breaker which is capable of meeting the aforesaid electrical requirements. The device disclosed in the Hammerly application, however, does not provide trip indication. That is, it is not possible to tell by merely looking at the device when it is in use, whether it is in the automatically-opened condition.

Also, while the aforesaid Hammerly structure provides a circuit protective device or circuit breaker which is capable of automatically opening a circuit upon the occurrence of predetermined conditions, it is not usable as a switch. In other words, it cannot be placed in a stable off condition by operation of the handle. The Hammerly device is therefore only a resettable protector which is always closed except when opened automatically by certain current conditions.

It is an object of the present invention to provide a simplified electric circuit breaker which is capable of performing the function of protecting the branch circuit connected thereto adequately, in accordance with Underwriters Laboratories requirements and Electrical Inspectors requirements both as to overload conditions and short circuit conditions.

I It is another object of the invention to provide such a simplified circuit breaker which provides a readily visible external indication of whether it has been opened automatically, i.e., trip indication.

It is a further object of the invention to provide such a circuit breaker which is also capable of performing a normal switching function, that is, which can be placed in an off condition manually when desired in order to render the circuit connected thereto tie-energized so as to permit work thereon.

Our present invention is an improvement upon the invention of the above mentioned application or" Herman I. Hammerly, Serial No. 236,165, which invention was made by the said Herman I. Hammerly prior to our invention. We therefore do not herein claim anything shown or described in the said Hammerly application, which is to be regarded as prior art with respect to the present application.

in the drawings,

FIGURE 1 is a side elevation view of an electric circuit breaker incorporating the invention, the enclosure cover being removed;

FIGURE 2 is an end elevation view of the circuit breaker of FIGURE 1;

FIGURE 3 is a perspective view of the insulating casing and one operating part, both being shown in fragmental-y form;

FIGURE 4 is a view similar to FTGURE 1 but showing the parts in the off position;

FIGURE 5 is a view similar to FIGURE 4, showing the parts in the automatically open or tripped position, and

FIGURE 6 is a partial side elevation view similar to FIGURE 1, showing the parts in the condition which they occupy immediately after release or automatic tripping.

Referring to the drawings, the invention is shown as incorporated in an electric circuit breaker having a molded insulating casing 10 comprising a body 10A and a removable side cover 193. A line terminal member 11 is supported on the insulating body MA and carries a line terminal screw 12. The inner end of the line terminal member strip 11 is extended to provide a contact arm portion and carries a relatively movable contact 13. The end 11A of the contact supporting arm 11 is extended beyond the movable contact 13 for a purpose to be described. The movable contact 13 engages a stationary contact 14 which is rigidly trapped in a suitably conforming recess in the molded insulating casing and which carries an elongated bimetallic strip 15. The bimetallic strip 15 carries an adjustable calibrating screw 16 adjacent its free end, which is connected by a flexible conductor 17 to a load terminal member 18 suitably supported on the insulating casing 1d and carrying a load wire connector 19.

An elongated relatively wide thin flat insulating slide or shutter 29 is slidably supported in the insulating casing 10 by having its opposite edge portions slidably guided in conforming grooves in the inner opposed side walls of the insulating casing and cover (see FIGURE 3). The slide it! includes a relatively wide flange portion 21 and an opposite edge portion 21A which ride in the aforesaid grooves. The slide 2t also includes an offset shelf or support 22 against which a compression spring 23 bears, for a purpose to be described, and a latch surface 24 which serves to engage with the calibrating screw 16 for a purpose to be described. The insulating slide further has a generally rectangular opening or window 25 therein adjacent its outer end. When the slide 20 is in the position shown in FIGURE 1, the window 25 is positioned so that the movable contact 13 can and does engage the stationary contact 14 therethrough.

Upon the passage of excess or overload current through the contacts and through the bimetallic strip 15, the bimetallic strip 15 warps so as to move the calibrating screw 16 to the right as viewed in FIGURE 1, disengaging the calibrating screw 16 from the latch surface 24 of the slide 20.

When this occurs, the compression spring 23 acting on the projection 22, quickly moves the insulating slide 20 upwardly so as to bring the tapered portion 2'7 between the movable contact 13 and the stationary contact 14, thereby interrupting the current. The slide 29 therefore constitutes a trip member or a releasable member, which is normally latched, but which is releasable to cause automatic opening of the contacts. The parts then move to the tripped condition as shown in FIGURE 5.

For the purpose of resetting the insulating slide 20, and also for providing a manual switching operation in a manner to be described, an operating handle 28 is provided of insulating material, slidably supported between the upstanding end Walls 18C and 16D of the base 16A.

.The insulating handle 23 includes a downwardly extending projection 29 which is adapted to engage the upper end of the insulating slide 2% and to depress it to the point where the latch 24 once again reengages the calibrating screw 16. The operating handle 28 also includes a downwardly extending tapered projection 30 having a flattened portion 31. When the handle 28 is depressed, the projection portion 30 engages the upwardly bent portion 11A of the contact arm strip 11, and forces the movable contact 13 away from contacting position with the stationary contact 14. Further depression of the insulating handle 28 causes the curved portion of the end portion 11A to ride up onto the flattened portion 31 of the projection 30, which causes these two parts to remain in this position, thus providing a stationary or stable off position.

The device may be placed in the on condition thereafter by simply pulling the handle 28 outwardly, to the position of FIGURE 1.

The handle 28 also has a sideways-extending projection 32 which serves as a stop or an abutment for a first compression spring 33, and which is spaced away from the remaining portion of the handle 28 to provide space for a second compression spring 34. The compression spring .34 has its upper end in engagement with the upper wall portion E of the insulating base 19A, and its lower end in engagement with the projection 32 of the handle 28. As a result, the compression spring 33 urges the handle member 28 upwardly, such movement being resiliently limited by the shorter compression spring 34. The handle 28 is therefore held in a mid-position as determined by the comparative forces of these two springs, for a purpose to be described. If desired, the

spring

33 and 34 may be parts of a single spring, the projection 32 being formed to enter between turns thereof.

The operating handle 28 also includes a diagonally extending stripe 35. Referring to FIGURE 4, the casing is also provided with a slanting portion extending substantially at right angles to the direction of the diagonal stripe 35 of the handle 28. The slanting portion 36 of the casing carries on, off, and trip indications, as shown in FIGURE 4. It will be observed that as the handle 28 is raised or lowered, the position of the diagonal stripe 35 changes with respect to the markings on the portion 36, and thereby serves as a visual indication of the condition of the circuit breaker.

It will be observed that the portions of the insulating base 10A and the cover 103 which are adjacent the slide are formed to closely surround the slide and to provide a hole or aperture into which it is slidably received. See FIGURE 3.

By reference to FIGURE 6, it will be noted that following passage of the insulating slide portion 27 between the movable contact 13 and the stationary contact 14, the end of the movable contact 13 rides on the portion 27 of the insulating slide 20, thereby pressing it against the surface 38A of the boss 33. It will also be observed that following insertion of the edge of the insulating member 27 between the movable contact 13 and the stationary contact 14, there is no path for the arc to take between the movable and stationary contacts except around the end of the slide 27. This condition is shown in FIGURE 6 in which the slide 20 is shown in an intermediate position following tripping and before reaching the full end of its travel.

When the operating handle 23 is in the on position as shown in FIGURE 1, it is resiliently held in an intermediate position, as described above. Upon the occurrence of tripping, the slide 20 is projected upward by the compression spring 23 as previously described, and the end portion 20A engages the lower surface of the projection 29 of the handle 28 and forces the handle 28 upwardly a small amount further above the on position, causing the indicating strip to move to the indication tripped. A trip indicating handle position is thus provided, as shown in FIGURE 5, which is different from the on and off positions.

It will be observed that the bimetallic strip 15 is supported solely on the stationary contact 14 by being rigidly attached thereto such as by brazing. These two members, are, in turn, held in the insulating casing only by the conforming fitting of the stationary contact 14 between the corresponding side walls of the

bosses

38 and 39.

One side of the insulating casing 10A has a portion 49 thereof cut away to provide an opening 4d through which access may be had to the calibrating screw 16 for adjusting purposes. The aperture 49 is closed by a relatively thin resilient insulating cover 41 which is snapped in place between the overhanging

ledge portions

42 and 43 as shown.

While the invention has been described in only one specific embodiment, it will be readily apparent that many modifications thereof may be made, and we therefore intend by the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.

What we claim as new and desire to secure by Letters 0 Patent of the United States is:

1. An electric circuit breaker comprising:

(a) an insulating casing,

(b) at least two contacts mounted in said casing and movable relative to each other between open and closed circuit positions,

(0) a manually operable handle member mounted in said casing and reciprocally movable into and out of said insulating casing between off and on positions respectively to operate said contacts between said open and closed circuit positions respectively,

(d) current responsive means in said casing for automatically initiating movement of said contacts to said open circuit position upon the occurrence of predetermined current conditions,

(e) first biasing means in said casing biasing said op erating handle outwardly of said insulating casing,

(f) second biasing means in said casing resiliently limiting movement of said handle outwardly of said casing, and normally retaining said handle in said on position, and

(g) supplementary biasing means in said casing releasably held and released upon automatic operation of said contacts to said open circuit position to add its bias to said first biasing means whereby said operating handle is moved to a trip-indicating position further outward of said insulating casing upon automatic opening of said contacts.

2. An electric circuit breaker comprising:

(a) an insulating casing,

(b) a manually operable handle member mounted in said casing and movable reciprocally inwardly and outwardly of said insulating casing between off and on positions respectively,

(c) at least two relatively movable contacts in said casing,

(d) a trip member in said casing releasable to cause automatic opening of said contacts, and latch means normally latching said releasable member,

(e) first biasing means in said casing biasing said operating handle outwardly of said insulating casing,

(f) second biasing means in said casing resisting movement of said handle outwardly of said insulating casmg,

(g) third biasing means in said casing biasing said releasable member in a direction to cause automatic opening of said contacts,

(h) current responsive means in said casing operable upon the occurrence of predetermined current conditions to cause said latch member to release said releasable member,

(i) said releasable member having a portion engageable with said manually operable member when released to add the force of said third biasing means to said first biasing means to move said operating handle to a trip indicating position against the bias of said second biasing means farther outward of said casing than on position.

3. An electric circuit breaker comprising:

(a) an insulating casing,

(b) at least two relatively movable contacts in said casing,

(c) a manually operable handle member supported in said casing for reciprocal movement inwardly and outwardly of said casing for moving said relatively movable contacts between open and closed circuit positions respectively,

(d) first biasing means in said casing constantly biasing said operating member outwardly of said insulating casing,

(e) second biasing means in said casing resiliently limiting outward movement of said operating member under the influence of said first biasing means,

(f) a trip member in said casing movable to initiate automatic opening of said contacts,

(g) third biasing means in said casing biasing said trip member for movement to cause automatic opening of said contacts,

(h) current responsive latch means in said casing normally restraining said trip member from tripping movement, said current responsive means being operable upon the occurrence of predetermined current conditions to release said trip member,

(i) said trip member having a portion engageable with said manually operable member for moving said manually operable member farther outwardly of said enclosure upon release of said releasable means whereby to indicate tripped condition of said circuit breaker.

4. An electric circuit breaker comprising:

(a) an insulating casing,

(b) a relatively stationary contact mounted in said casing,

(c) a relatively movable contact mounted in said casing,

(d) biasing means in said casing biasing said relatively movable contact into engagement with said relatively stationary contact,

(e) an insulating slide slidably supported in said insulating casing, and movable between 21 released position in which a portion of said slide is interposed between said contacts and a latched position in which no part of said slide is between said contacts,

(f) biasing means in said casing biasing said insulating slide toward said released position to cause automatic opening of said contacts,

(g) current responsive means in said casing normally latching said insulating slide against movement in said direction,

(h) a manually engageable operating handle in said casing reciprocally movable into and out of said insulating casing, to move said slide from said released to said latched position, said operating handle having a portion engageable with said movable contact biasing means to move said relatively movable contact to disengaged position as said handle moves said slide to said latched position,

(i) said manually operable handle and said biasing means including cooperating formations for retaining said handle in an inward actuated position and to retain said movable contact in said disengaged position until released by application of a positive external force causing outward movement of said operating handle.

5. An electric circuit breaker comprising:

(a) a casing of insulating material,

(b) at least one stationary contact mounted in said insulating casing,

(c) at least one relatively movable contact mounted in said insulating casing and movable between en gaged and disengaged positions with respect to said stationary contact,

(d) an elongated slide of insulating material slidably supported in said insulating casing,

(e) biasing means in said casing biasing said insulating slide for movement to an interrupting position between said relatively movable and said relatively stationary contacts,

(f) current responsive means in said casing normally restraining said insulating slide from movement to ward said interrupting position,

(g) a manually operable insulating handle member in said casing movable between an on position outward of said casing and an off position inward of said casing, said operating handle including a portion engageable with said relatively movable contact member when said handle is moved to said off position to move said contact to a disengaged position with respect to said stationary contact,

(h) first biasing means in said casing biasing said manually operable handle member from said off position toward said on position,

(i) second biasing means in said casing opposing movement of said manually operable handle member outwardly of said insulating casing beyond said on position,

(j) said insulating slide including a portion engageable with said manually operable member upon release thereof by said current responsive means, whereby said insulating slide serves to cause said manually operable member to move to a position farther outward of said insulating casing than said on position, for the purpose of indicating the automatically opened condition of the circuit breaker.

6. An electric circuit breaker comprising:

(a) a casing of insulating material,

(b) a relatively stationary contact mounted in said insulating casing,

(c) a relatively movable contact mounted in said insulating casing,

(d) an insulating slide slidably supported in said insulating casing and movable between a latched position in which no portion thereof is between said contacts and a released position in which a portion thereof isbetween said contacts,

(e) first biasing means in said casing biasing said insulating slide for movement from said latched to said released position,

(f) a manually engageable handle member reciprocally mounted in said insulating casing and movable between an on outer position in which said handle is out of engagement with said relatively movable contact and an inner off position in which a portion of said handle is in engagement with a portion of said movable contact member and serves to hold said movable contact member in a position in which it is disengaged from said stationary contact member,

(g) an elongated coil type spring member having opposite ends thereof in abutting engagement with portions of said insulating casing, said operating handle having a portion thereof operably connected to an intermediate portion of said spring, whereby said handle is resiliently maintained in an intermediate position,

(h) said insulating slide including a portion engageable with said manually operable handle upon release thereof by said current responsive means to move said handle to a position farther outward of said insulating casing than said on position whereby to indicate tripped or automatic opened condition of said circuit breaker.

(References on following page) 7 8 References Qited by the Examiner 2,487,422 11/ 49 Carla 200-1 16 2,506,148 5/50 Hammerly 200-6 X UNITED STATES PATENTS 2,842,641 7/58 Page 2001 16 X 1,492,967 5/24 1301116 2 912 546 11 59 A 200-116 1,732,295 10/ 29 Aichele. 5 1,956,194 4/34 Grady. FOREIGN PATENTS 2,073,103 3/37 Hodgkins 200-116 275,038 8/27 Great Britain.

2,085,018 6/37 Grady. 2,287,994 1/40 Hammerly 200151 X BERNARD A. GILHEANY, Primary Examiner.

Claims

1. AN ELECTRIC CIRCUIT BREAKER COMPRISING: (A) AN INSULATING CASING, (B) AT LEAST TWO CONTACTS MOUNTED IN SAID CASING AND MOVABLE RELATIVE TO EACH OTHER BETWEEN OPEN AND CLOSED CIRCUIT POSITIONS, (C) A MANUALLY OPERABLE HANDLE MEMBER MOUNTED IN SAID CASING AND RECIPROCALLY MOVABLE INTO AND OUT OF SAID INSULATING CASING BETWEEN "OFF" AND "ON" POSITIONS RESPECTIVELY TO OPERATE SAID CONTACTS BETWEEN SAID OPEN AND CLOSED CIRCUIT POSITIONS RESPECTIVELY, (D) CURRENT RESPONSIVE MEANS IN SAID CASING FOR AUTOMATICALLY INITIATING MOVEMENT OF SAID CONTACTS TO SAID OPEN CIRCUIT POSITION UPON THE OCCURRENCE OF PREDETERMINED CURRENT CONDITIONS, (E) FIRST BIASING MEANS IN SAID CASING BIASING SAID OPERATING HANDLE OUTWARDLY OF SAID INSULATING CASING, (F) SECOND BIASING MEANS IN SAID CASING RESILIENTLY LIMITING MOVEMENT OF SAID HANDLE OUTWARDLY OF SAID CASING, AND NORMALLY RETAINING SAID HANDLE IN SAID "ON" POSITION, AND (G) SUPPLEMENTARY BIASING MEANS IN SAID CASING RELEASABLY HELD AND RELEASED UPON AUTOMATIC OPERATION OF SAID CONTACTS TO SAID OPEN CIRCUIT POSITION TO ADD ITS BIAS TO SAID FIRST BIASING MEANS WHEREBY SAID OPERATING HANDLE IS MOVED TO A TRIP-INDICATING POSITION FURTHER OUTWARD OF SAID INSULATING CASING UPON AUTOMATIC OPENING OF SAID CONTACTS.