US3581261A - Molded case circuit breaker having an auxiliary contact separating spring - Google Patents
Molded case circuit breaker having an auxiliary contact separating spring Download PDFInfo
- Publication number
- US3581261A US3581261A US845275A US3581261DA US3581261A US 3581261 A US3581261 A US 3581261A US 845275 A US845275 A US 845275A US 3581261D A US3581261D A US 3581261DA US 3581261 A US3581261 A US 3581261A
- Authority
- US
- United States
- Prior art keywords
- circuit breaker
- spring
- movable contact
- pivot
- contact member
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
- H01H71/10—Operating or release mechanisms
- H01H71/50—Manual reset mechanisms which may be also used for manual release
- H01H71/52—Manual reset mechanisms which may be also used for manual release actuated by lever
- H01H71/529—Manual reset mechanisms which may be also used for manual release actuated by lever comprising an electroresponsive element forming part of the transmission chain between handle and contact arm
Definitions
- This invention relates to circuit breakers and more particularly to improvements in molded case circuit breakers.
- Molded case circuit breakers have been widely employed in the distribution and control of electricity and their popularity continues to increase.
- the standard circuit breakers which had a short circuit current interrupting capacity of 5,000 ampcreshave been satisfactory.
- the interrupting capacity of the circuit breakers be increased.
- the improved circuit breakers must be interchangeable with, and if possible externally identical to, the prior units so as to allow continued use of the unchanged panelboards, accessories and the like and to permit improvement or upgrading of existing installations.
- the invention is illustrated, in certain of its aspects, as applied to a multipole molded case circuit breaker.
- a circuit breaker is illustrated and described in detail in U.S. Pat.
- FIG. I is a side view of an end pole of a three pole circuit breaker with the cover removed and certain parts being shown in fragmentary section. The mechanism is shown in the contacts-closed (closedcircuit) position;
- FIG. 2 is a fragmentary cross section of a portion of the mechanism in FIG. I viewed along the line 2-2 therein.
- the circuit breaker case has an inner wall 10 that cooperates with an outer wall 12 to form a cavity 14.
- Cavity l4, and the other like cavities each contain a complete circuit breaker mechanism, including a pair of contacts, a contact-operating linkage, an overload release means and a common release means which forms a part of each pole of the three-pole circuit breaker.
- Common operating means including externally projecting handle 16, is provided for simultaneous operation of all of the poles.
- a common trip bar mechanism 18 is operatively connected to all of the poles.
- Each pole includes a first terminal 20 rigidly'carrying a stationary contact 22.
- Movable companion contact 24 engages contact 22' when the circuit breaker is closed, movable contact 24 being supported on elongated contact carrying member 26.
- Contact-carrying member 26 is pivoted near its center on a transverse coil spring 28. The contacts engage and disengage within a well-known type of arc chute 29 that includes metallic arc splitter plates 29a, venting passage 29b and metallic vent screen 29c.
- An ambient temperature compensating bimetal 32a has its upper end curved about bearing 34 and its lower end, which constitutes its latched end, is slidably guided by a formed portion of actuator 32 so that the lower tip of bimetal 32 a is projected to a variable extent in dependence on the ambient temperature.
- the overcurrent releasable latch 37 includes a current responsive bimetal 38 that is united at one end to the contact arm 26, providing electrical connection and a rigid mechanical connection at this point.
- the elongated contact member 26 constitutes a conductive support that carries and unites bimetal 38 and the magnetic pole structure 40 of a tripping electromagnet.
- the pole structure 40 is also united to bimetal 36 and to contact arm 26 by a rivet 26!) that extends integrally, through the bimetal and the pole structure, from contact arm 26.
- Pole structure 40 is wider than the bimetal 38 and extends all the way acrossthe bimetal except for a cutout portion to accommodate a conductor 42 of flexible conductive braid that is united to the bimetal adjacent its right-hand end as viewed in the drawings.
- a magnetic armature 44 is positioned on the side of bimetal 38 opposite from pole structure 40 and has lateral pivots 44a retained in notches in the pole structure as shown. Armature 44 is wider than bimetal 38 at the right of pivot 44a and extends into latching engagement with actuator 32. Armature 44 terminates to the left of the pivots 44a.
- a low profile spring 46 biases the armature counterclockwise about pivots 44a.
- Transverse coil spring 28 which serves a pivot for contact arm 26, is housed in a pair of cylindrical bosses 10a and I2a that extend inwardly toward one another within the cavity 14.
- Spring 28 provides contact pressure between the contacts 22 and 24 and permits overtravel of the contact carrying member '26 as more fully explained in U.S. Pat. No. 2,681,396.
- a compression spring 50 is interposed between respective projections on contact carrying member 26 and handle 16 biasing both the member and the handle to their open position when the circuit breaker is open. As shown in FIG. I this compression spring provides strong contact-opening bias when the breaker is closed. In the closed configuration of the mechanism shown in FIG. I, actuator 32 is latched by armature 44 and the counterclockwise spring bias applied to contact carrying member 26 is resisted by an overset toggle consisting of trip bar 18 and pivoted handle 16. counterclockwise motion of handle 16 limited by the casing 10. In this configuration, spring 50 provides a limited bias for operating handle I6 in the contact-opening direction.
- the speed of opening of the contacts upon occurrence of an overload determines the interrupting capacity of the circuit breaker.
- the speed of opening is largely dependent upon the force of compression spring 50.
- An increase in force of spring 50 could produce faster opening.
- spring 50 and pivot spring 28 are in opposition and therefore an increase in force of spring 50 will result in a reduction in contact pressure.
- An increase of force in spring 50 is therefore not suitable as a way of increasing the speed of opening.
- a novel solution is provided to the problem of increasing the opening speed of the circuit breaker by the provision of a torsion spring 52 that is positioned about the boss I0a. One end 52a of torsion spring 52 engages a stop 10b on the wall I0 and the other end is formed as a hook 52b for engagement with the contact carrying member 26.
- Torsion spring 52 acts on the elongated contact carrying member 26 in the same direction as pivot spring 28 when the contacts are closed and therefore spring 52 actually increases the contact pressure. Upon release of the contact carrying member, spring 52 accelerates the movement of contact 24 to the open circuit position.
- the toggle comprising handle 16 and trip bar 18 lock the contacts closed, under the control of armature 44 of the overcurrent releasable latch 37.
- armature 44 of the overcurrent releasable latch 37 Upon downward deflection of the armature magnetically or by pressure from current responsive bimetal 38, elongated contact carrying member 26 is driven counterclockwise by spring 50 and by spring 52, as actuator 32 swings clockwise about its pivot 30.
- Springs 50 and 52 are now free to accelerate the separation of the contacts 22, 24.
- the addition of spring 52 contributes to increased contact pressure and increased speed of opening of the contacts with only a small, barely noticeable to the operator of handle 16, increase in the force required to close the circuit breaker.
- the molded case circuit breaker illustrated and described above is a three pole, 70 A., 240 v.
- circuit breakers having one, two or more poles.
- a molded case circuit breaker having a stationary contact, an elongated movable contact member supported on a pivot between its ends, said elongated movable contact member having a contact at one end engageable with and disengageable from said stationary contact, and having an actuator pivoted at its opposite end and having an overcurrent releasable latch normally restraining said actuator, and a pivoted handle and a link connected to said handle forming a toggle for operating said actuator and for thereby operating said elongated movable contact member to close the contacts, said circuit breaker including means for urging said elongated movable contact member in a direction to increase the pressure between the companion contacts when the contacts are engaged and for urging said elongated movable contact member away from said stationary contact when said actuator is released by the overcurrent releasable latch, said last-named means including a torsion spring positioned about said pivot of said elongated movable contact member with one end of the spring bearing against the circuit breaker case and the other end
- a circuit breaker according to claim 1 wherein said circuit breaker has a case of insulation, said pivot of elongated movable contact member being housed in portions of said case, said torsion spring being positioned about a portion of said pivot housing.
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- Breakers (AREA)
Abstract
Description
Claims (3)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US84527569A | 1969-07-28 | 1969-07-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3581261A true US3581261A (en) | 1971-05-25 |
Family
ID=25294831
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US845275A Expired - Lifetime US3581261A (en) | 1969-07-28 | 1969-07-28 | Molded case circuit breaker having an auxiliary contact separating spring |
Country Status (1)
Country | Link |
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US (1) | US3581261A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4366354A (en) * | 1980-12-29 | 1982-12-28 | Federal Pacific Electric Company | Circuit breaker with improved contact push-off spring |
US4375628A (en) * | 1981-10-09 | 1983-03-01 | Federal Pacific Electric Company | Circuit breaker |
US8872606B1 (en) | 2013-04-23 | 2014-10-28 | Eaton Corporation | Bimetal and magnetic armature providing an arc splatter resistant offset therebetween, and circuit breaker including the same |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2583122A (en) * | 1948-10-25 | 1952-01-22 | Rousseau Claude | Circuit breaker switch |
US2681396A (en) * | 1952-05-01 | 1954-06-15 | Fed Electric Prod Co | Circuit breaker with spring biased pivot for movable contact members |
-
1969
- 1969-07-28 US US845275A patent/US3581261A/en not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2583122A (en) * | 1948-10-25 | 1952-01-22 | Rousseau Claude | Circuit breaker switch |
US2681396A (en) * | 1952-05-01 | 1954-06-15 | Fed Electric Prod Co | Circuit breaker with spring biased pivot for movable contact members |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4366354A (en) * | 1980-12-29 | 1982-12-28 | Federal Pacific Electric Company | Circuit breaker with improved contact push-off spring |
US4375628A (en) * | 1981-10-09 | 1983-03-01 | Federal Pacific Electric Company | Circuit breaker |
US8872606B1 (en) | 2013-04-23 | 2014-10-28 | Eaton Corporation | Bimetal and magnetic armature providing an arc splatter resistant offset therebetween, and circuit breaker including the same |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: CHALLENGER DPT CORPORATION, PENNSYLVANIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FEDERAL PACIFIC ELECTRIC COMPANY;REEL/FRAME:004747/0326 Effective date: 19860630 Owner name: CHALLENGER LIC CORPORATION, PENNSYLVANIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FEDERAL PACIFIC ELECTRIC COMPANY;REEL/FRAME:004747/0326 Effective date: 19860630 Owner name: CHALLENGER ACQUISITION CORPORATION, PENNSYLVANIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FEDERAL PACIFIC ELECTRIC COMPANY;REEL/FRAME:004747/0326 Effective date: 19860630 Owner name: CHALLENGER FUSE CORPORATION, PENNSYLVANIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FEDERAL PACIFIC ELECTRIC COMPANY;REEL/FRAME:004747/0326 Effective date: 19860630 Owner name: CHALLENGER DPT CORPORATION, MALVERN, PA. A CORP. O Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:FEDERAL PACIFIC ELECTRIC COMPANY;REEL/FRAME:004747/0326 Effective date: 19860630 Owner name: CHALLENGER LIC CORPORATION, MALVERN, PA. A CORP. O Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:FEDERAL PACIFIC ELECTRIC COMPANY;REEL/FRAME:004747/0326 Effective date: 19860630 Owner name: CHALLENGER ACQUISITION CORPORATION, MALVERN, PA. A Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:FEDERAL PACIFIC ELECTRIC COMPANY;REEL/FRAME:004747/0326 Effective date: 19860630 Owner name: CHALLENGER FUSE CORPORATION, MALVERN, PENNSYLVANIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:FEDERAL PACIFIC ELECTRIC COMPANY;REEL/FRAME:004747/0326 Effective date: 19860630 |
|
AS | Assignment |
Owner name: PROVIDENT INDUSTRIES, INC., NEW YORK Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:AMERICAN CIRCUIT BREAKER CORPORATION, FORMERLY AMERICAN PROPERTIES CORPORATION, BY WHEELER FINANCIAL SERVICES, AS TRUSTEE;REEL/FRAME:005000/0681 Effective date: 19881225 Owner name: PROVIDENT INDUSTRIES, INC., A CORP. OF NY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:AMERICAN CIRCUIT BREAKER CORPORATION, FORMERLY AMERICAN PROPERTIES CORPORATION, BY WHEELER FINANCIAL SERVICES, AS TRUSTEE;REEL/FRAME:005000/0681 Effective date: 19881225 |
|
AS | Assignment |
Owner name: PROVIDENT INDUSTRIES, INC., NEW YORK Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:AMERICAN CIRCUIT BREAKER CORPORATION BY WHEELER FINANCIAL SERVICES, TRUSTEE;REEL/FRAME:005012/0779 Effective date: 19881220 Owner name: PROVIDENT INDUSTRIES, INC., A CORP. OF NY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:AMERICAN CIRCUIT BREAKER CORPORATION BY WHEELER FINANCIAL SERVICES, TRUSTEE;REEL/FRAME:005012/0779 Effective date: 19881220 |