US3930213A - Manually operable circuit interrupter with automatic current overload protection - Google Patents

Manually operable circuit interrupter with automatic current overload protection Download PDF

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Publication number
US3930213A
US3930213A US51337174A US3930213A US 3930213 A US3930213 A US 3930213A US 51337174 A US51337174 A US 51337174A US 3930213 A US3930213 A US 3930213A
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US
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Grant
Patent type
Prior art keywords
lever
latch
latch lever
position
retainer
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
Application number
Inventor
Edward L Richards
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Westinghouse Electric Corp
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Westinghouse Electric Corp
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    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10Operating or release mechanisms
    • H01H71/50Manual reset mechanisms which may be also used for manual release
    • H01H71/52Manual reset mechanisms which may be also used for manual release actuated by lever
    • H01H71/522Manual reset mechanisms which may be also used for manual release actuated by lever comprising a cradle-mechanism
    • H01H71/525Manual reset mechanisms which may be also used for manual release actuated by lever comprising a cradle-mechanism comprising a toggle between cradle and contact arm and mechanism spring acting between handle and toggle knee
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10Operating or release mechanisms
    • H01H71/50Manual reset mechanisms which may be also used for manual release
    • H01H71/505Latching devices between operating and release mechanism
    • H01H2071/508Latching devices between operating and release mechanism with serial latches, e.g. primary latch latched by secondary latch for requiring a smaller trip force
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10Operating or release mechanisms
    • H01H71/50Manual reset mechanisms which may be also used for manual release
    • H01H71/505Latching devices between operating and release mechanism
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H73/00Protective overload circuit-breaking switches in which excess current opens the contacts by automatic release of mechanical energy stored by previous operation of a hand reset mechanism
    • H01H73/02Details
    • H01H73/04Contacts
    • H01H73/045Bridging contacts

Abstract

A motor circuit interrupter characterized by a manually operated fast-acting switch and a bi-metallic over-load relay for trip opening of the switch contacts in response to current overloads. The switch comprises means for moving electric contacts between open and closed positions which means includes a releasable arm which is movable between latched and unlatched positions. When in the ''''unlatched'''' condition, the contacts are open and the operating means cannot be operated to effect a re-closing of the contacts. The switch further comprises a pivoted latch lever operatively connected to the releasable arm to retain the arm in the latched condition, or for effecting unlatching of the arm, a latch retainer lever to retain the latch lever in the latch position said retainer lever is operatively connected to the trip plate of the overload relay to effect unlatching of the latch lever and releasable arm in response to an overload current. The retainer lever is spring-biased to the latch position with the latch lever and the retainer lever comprising an extension engageable with the latch lever when the latter is in the unlatched position to maintain the latch lever in a relatching position.

Description

United States Patent 1191 Richards MANUALLY OPERAELE tItRCUlT Primary Examiner-Harold Broome Attorney, Agent, or FirmL. P. Johns 57 ABSTRACT A motor circuit interrupter characterized by a manu- Dec. 30, 1975 ally operated fast-acting switch and a bi-metallic overload relay for trip opening of the switch contacts in response to current overloads. The switch comprises means for moving electric contacts between open and closed positions which means includes a releasable arm which is movable between latched and unlatched positions. When in the unlatched" condition, the contacts are open and the operating means cannot be operated to effect a re-closing of the contacts. The switch further comprises a pivoted latch lever operatively connected to the releasable arm to retain the arm in the latched condition, or for effecting unlatching of the arm, a latch retainer lever to retain the latch lever in the latch position said retainer lever is operatively connected to the trip plate of the overload relay to effect unlatching of the latch lever and releasable arm in response to an overload current. The retainer lever is spring-biased to the latch position with the latch lever and the retainer lever comprising an extension engageable with the latch lever when the latter is in the unlatched position to maintain the latch lever in a relatching position.

5 Claims, 5 Drawing Figures US. Patent Dec. 30, 1975 Sheet 2 0f 2 MANUALLY OPERABLE cIRcUIr INTERRUPTER WITH AUTOMATIC CURRENT OVERLOAD PROTECTION CROSS-REFERENCE TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a circuit interrupter having a switch tripping mechanism responsive to current overloads.

2. Description of the Prior Art Motor circuit interrupters of prior construction have been provided with current overload protective devices that function satisfactorily in response to abnormal currents such as overcurrents, ground fault currents, and short circuits, that occur in an electrical distribution system. Circuit interrupters of that type function satisfactorily for the purposes intended, but it is desirable under some circumstances to also provide for currents in excess or below the rating of the heater elements selected for the motor to be 'controlled. An interrupter for a given current rating may function entirely satisfactorily in one location which is relatively close to the current source, but function unsatisfactorily at a location which is located at a considerable distance from that source. The variations in current are due to differences in efficiency and design of motors rated at the same horsepower as produced by various manufacturers; and extent of voltage drop occurring in the feeder conductors from the voltage supply source to the motor windings. Accordingly, it is desirable to provide a motor circuit interrupter having adjustable overload protection adaptable to functioning satisfactorily for the motor current specifically encountered.

SUMMARY OF THE INVENTION It has been found in accordance with this inventiop that the foregoing problem may be overcome by providing a circuit interrupter with adjustable overload protection which comprises relatively movable contact means and means releasable to effect automatic opening of said contact means, operating means for moving the contacts between open and closed positions, the operating means including a releasable arm movable between latched and unlatched positions, a pivoted latch lever operable to effect latching or unlatching of the releasable arm, a latch retainer lever effective to releasably retain the latch lever in the latched position; a trip mechanism comprising a trip plate, a position adjusted pivoted trip lever, and bimetal means for actuating the latch retainer lever in response to excessive heat radiated to the bimetals by the heater elements when subjected to current in excess of the rating of the heater elements, the trip plate being operatively connected to the retainer lever to move the latch lever to the unlatched position, and the latch retainer lever being spring-biased in the latched position.

The advantage of the device of this invention is that a manually operated toggle mechanism which provides switching control to alternately close and open electrical contacts is combined with an overload relay and 2 provided with lever means associated with the relay for positively tripping the switch in response to an overload current.

. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a three-pole overload relay connected to a circuit interrupter in accordance with this invention;

FIG. 2 is a vertical sectional view taken on the line II-II of FIG. 1, with the outer housing omitted;

FIG. 3 is a vertical sectional view taken on the line IIIIII of FIG. 2 showing the trip mechanism in the reset position;

FIG. 4 is a vertical sectional view showing the trip mechanism in the tripped position; and

FIG. 5 is a vertical sectional view of the trip mechanism in a position intermediate those of FIGS. 3 and 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 a circuit" interrupter is generally indicated at 7 and it comprises'a manually operated switch 9 and an overload relay 11, both of which are mounted on a supporting base 13.

Inasmuch as a detail description of the switch 9 is set forth in the application of Edward L. Richards, Ser. No. 404,579, filed Oct. 9, 1973, the description is limited to the parts that are essential to the operation of the invention disclosed herein. Suffijce it to say the switch 9 is a multi-pole, such as a three-pole, switch which includes a pair of stationary contacts 17, a pair of movable contacts 19, as well as movable contact carrier means 21. The switch 9 also comprises a manually operated over-center toggle mechanism generally indicated at 23 which in turn comprises a releasable arm 25 that is pivotally mounted on a pivot pin 27 that extends between a pair of upright frames 29 and 31 (FIG. 2). The overhead toggle mechanism 23 is enclosed within a housing 33 of electrically insulating material and includes a handle 35 which extends upwardly through the upper side of the housing.

As shown in FIG. 3 the right end of the releasable arm 25 is retained in a latched position by a trip mechanism which comprises a latch lever 37 and a latch retainer lever 39. The latch lever 37 is an L-shaped or bellcrank type lever which is pivoted on a pair of similar trunnions 41 extending from opposite sides thereof into corresponding apertures in spaced upright frames 29, 31. The latch lever 37 also includes an opening 43 in which the left end of the arm 25 is seated when in the latched position as shown in FIG. 3. The lower end of the latch lever 37 extends to and is engaged by the latch retainer lever 39 as shown in FIG. 3.

The latch retainer lever 39 is a substantially vertically extending member having similar trunnions 45 extending from opposite sides thereof and seated 'in corresponding apertures in the spaced upright frames 29, 31. Hole 47 is disposed in the latch retainer lever 39 below the trunnions 45 and outwardly extending lips 49 and 51 are provided at the lower and upper sides of the hole 47. The lower end portion of the latch retainer lever 37 is disposed in an aperture 53 of a trip plate 55 which as shown in FIG. 1 extends from the overload relay 11. When the trip plate 55 is moved by the relay to the left as viewed in FIG. 3 the latch retainer lever 39 rotates clockwise until the lower extremity of the latch retainer lever 37 moves out of the hole 47 and from the lip 49, whereupon the latch lever rotates counterclockwise in response to an upper pressure applied to the upper side of the opening 43 by the releasable arm 25. The releasoccurs, the'heaters 73 cause the bi-metal 71 to move able arm 25 moves until it strikes a stop pin 57 which extends between the upright frames 29, 31. To mini- '3 mize friction between the end of the arm 25 and the latch lever 37 a roller 59 is mounted on a pin 61 at the end of the arm. Movement of the retainer lever 39 and f latch lever 37 in the manner described constitutes tripping of the current interrupter 9 and causes the movable contacts 19 to separate from the stationary contacts 17 (FIG. 1).

The tripped position of the arm 25 is shown in FIG. 4 with the roller 59 in contact with the pin 57 as well as in contact with the upper end of the latch lever 37 whereby the latch lever 37 is maintained in the position shown. in FIG. 4. Thus the lower end of the lever is maintained at a position below the hole 47, where it remains until such time as the switch 9 is reset, the arm 25 is rotated counterclockwise about the pivot pin 27 until the roller 57 strikes a projection 63 on the lever and at the lower side of the opening 43. When the roller 59'strikes the projection 63 it causes the lever to rotate counterclockwise until the left end of the lever 37 isagain seated in the hole 47 of the retainer lever 39. The retainer lever 39 is biased counterclockwise by a wire spring 65 whereby it is normally urged against the lower end of the latch lever 37.

.7 4 77-, and the trip plate 55. When a current in excess of that'for which the heater elements are rated to handle the crossbar 75 against the lower end of the trip lever 77 causing the upper end thereof to rotate counterclockwise and pull the trip plate 55 to the left, whereupon the latch retainer lever 39 is rotated clockwise as i .1 set forth above.

In conclusion, the combination of the manual switch tripped voids the toggle mechanism of the manual switch which assumes a non-operative tripped position.

The upper end of the opening 43 of the lever 37 is reinforced by a projection 63 which engages the roller and provides a broader surface for contact therewith when the roller 59 is seated in the opening 43. The projection 63 includes a body portion 67a which is secured to the surface of the latch lever 37 in a suitable manner such as spot welding.

In order to prevent the retainer lever 39 and the latch lever 37 from becoming disposed in any undesirable position other than that shown in the latch position of FIG. 3 and the unlatch position of FIG. 4 the upper end of the retainer lever 39 includes an extension 69 (FIG. 5) which is adapted to engage the side of the lever 37 or the projection member 67a when the arm 25 is moving either up or down during tripping or resetting of the switch 9. Thus, if an excessive force is applied during tripping or resetting the latch lever 37 and the retainer lever 39 are maintained in the desired positions with respect to each other as shown in FIGS. 3 and 4.

Inasmuch as the overload relay is disclosed specifically in E. L. Richards application Ser. No. 471,740, filed May 20, 1974, the description of the relay is limited to the parts that are essential to operation of the invention disclosed herein.

The relay includes multiple bi-metals 71, bi-metal heaters 73, a cross bar 75, a position adjusted trip lever ln the latched position the overload protection mechanism'does not prevent operation of the switch in a normal manner between on and off positions during vnormal current conditions.

'fWhat is claimed is:

l. A circuit interrupting device comprising relatively movable contact means and means releasable to effect 'automatic opening of said contact means, operating means for moving the contacts between open and closed positions and comprising a releasable arm movable between latched and unlatched positions, a latch l'everoperable to effect unlatching of the releasable arm, a retainer plate effective to releasably retain the latch lever in the latched position, a trip device comprising a trip plate and bi-metal means for activating the trip plate in response to excessive currents, the trip plate: being operatively connected to the retainer plate to move the retainer plate to the unlatched position, and the retainer plate being spring-biased in the latched position with the latch lever and including an extension engageable with the latch lever when in the unlatched i. to maintain the latch lever in a relatching posi- 2. The circuit interrupting device of claim 1 in which the-extension comprises a portion extending toward the latch lever.

{3. The circuit interrupting device of claim 2 in which the latch lever is a first class lever, and the latch lever comprising one latching end portion latchingly engageable with the retainer plate and a second end portion ei'rgageable with said extension of the retainer plate.

4. The circuit interrupting device of claim 3 in which the retainer plate is a first class lever comprising a latchin gsurface engageable with said one latching end portion.-

The circuit interrupting device of claim 3 in which said second end portion comprises a latching surface forfretaining the releasable arm in the latched position.

Claims (5)

1. A circuit interrupting device comprising Relatively movable contact means and means releasable to effect automatic opening of said contact means, operating means for moving the contacts between open and closed positions and comprising a releasable arm movable between latched and unlatched positions, a latch lever operable to effect unlatching of the releasable arm, a retainer plate effective to releasably retain the latch lever in the latched position, a trip device comprising a trip plate and bimetal means for activating the trip plate in response to excessive currents, the trip plate being operatively connected to the retainer plate to move the retainer plate to the unlatched position, and the retainer plate being spring-biased in the latched position with the latch lever and including an extension engageable with the latch lever when in the unlatched position to maintain the latch lever in a relatching position.
2. The circuit interrupting device of claim 1 in which the extension comprises a portion extending toward the latch lever.
3. The circuit interrupting device of claim 2 in which the latch lever is a first class lever, and the latch lever comprising one latching end portion latchingly engageable with the retainer plate and a second end portion engageable with said extension of the retainer plate.
4. The circuit interrupting device of claim 3 in which the retainer plate is a first class lever comprising a latching surface engageable with said one latching end portion.
5. The circuit interrupting device of claim 3 in which said second end portion comprises a latching surface for retaining the releasable arm in the latched position.
US3930213A 1974-10-09 1974-10-09 Manually operable circuit interrupter with automatic current overload protection Expired - Lifetime US3930213A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US3930213A US3930213A (en) 1974-10-09 1974-10-09 Manually operable circuit interrupter with automatic current overload protection

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US3930213A US3930213A (en) 1974-10-09 1974-10-09 Manually operable circuit interrupter with automatic current overload protection
CA 236436 CA1044288A (en) 1974-10-09 1975-09-25 Manually operable circuit interrupter with automatic current overload protection
GB3974475A GB1515749A (en) 1974-10-09 1975-09-29 Manually operable circuit interrupter with automatic current overload protection

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US3930213A true US3930213A (en) 1975-12-30

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2838630A1 (en) * 1977-09-06 1979-03-08 Square D Co Multipole low-voltage switch with ueberstromausloesung
FR2424622A1 (en) * 1978-04-27 1979-11-23 Lee Wen Fong automatic magnetic switch
US4288767A (en) * 1976-12-16 1981-09-08 Lee Wen Fong Automatic magnetic switch
US4296396A (en) * 1979-01-31 1981-10-20 La Telemecanique Electrique Manual electric switch with thermal release
EP0563368A1 (en) * 1991-10-18 1993-10-06 Square D Co Current limiting circuit breaker.
WO2001065910A3 (en) * 2000-03-08 2002-01-31 Gen Electric Latch resetting arrangement
DE10139917A1 (en) * 2001-08-14 2003-02-27 Abb Patent Gmbh Switching mechanism for an electrical switching device, in particular for a motor protection switch

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2473901A (en) * 1947-07-31 1949-06-21 Westinghouse Electric Corp Push button operated circuit interrupter
US3179768A (en) * 1962-05-03 1965-04-20 Gen Electric Circuit breaker with mechanically isolated trip mechanism

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2473901A (en) * 1947-07-31 1949-06-21 Westinghouse Electric Corp Push button operated circuit interrupter
US3179768A (en) * 1962-05-03 1965-04-20 Gen Electric Circuit breaker with mechanically isolated trip mechanism

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4288767A (en) * 1976-12-16 1981-09-08 Lee Wen Fong Automatic magnetic switch
DE2838630A1 (en) * 1977-09-06 1979-03-08 Square D Co Multipole low-voltage switch with ueberstromausloesung
FR2424622A1 (en) * 1978-04-27 1979-11-23 Lee Wen Fong automatic magnetic switch
US4296396A (en) * 1979-01-31 1981-10-20 La Telemecanique Electrique Manual electric switch with thermal release
EP0563368A1 (en) * 1991-10-18 1993-10-06 Square D Co Current limiting circuit breaker.
EP0563368A4 (en) * 1991-10-18 1994-03-17 Square D Co Current limiting circuit breaker.
WO2001065910A3 (en) * 2000-03-08 2002-01-31 Gen Electric Latch resetting arrangement
DE10139917A1 (en) * 2001-08-14 2003-02-27 Abb Patent Gmbh Switching mechanism for an electrical switching device, in particular for a motor protection switch
EP1284494A3 (en) * 2001-08-14 2004-11-03 ABB PATENT GmbH Latch mechanism for a circuit breaker, particularly for a protective switch for a motor

Also Published As

Publication number Publication date Type
CA1044288A (en) 1978-12-12 grant
GB1515749A (en) 1978-06-28 application
CA1044288A1 (en) grant

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