US2668891A

US2668891A - Contact mechanism for circuit breakers

Info

Publication number: US2668891A
Application number: US318709A
Authority: US
Inventors: Jr Fritz Driescher
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-03-11
Filing date: 1952-11-04
Publication date: 1954-02-09
Anticipated expiration: 1971-02-09
Also published as: FR1070055A

Description

Feb. 9, 1954 F. DRIESCHER, JR 2,668,891

CONTACT MECHANISM FOR CIRCUIT BREAKERS Filed Nov. 4, 1952 INVENTOP Fri- '2 Dn scher, JT'.

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Patented Feb. 9, 1954 CONTACT -MECHANISM FOR CIRCUIT BREAKERS ,Fritz Driescher, J13, Moosburg fiermany ApplicationiNovember 4, 1952,Seria1 N0. 318,709

.Claims priority, a p ation German March 11, 19.52

6 Claims.

The present invention relates to contact mechanisms for circuit breakers, and more particularly to mechanisms of this characterwhich includean arcing chamber where an explosion accompanying the interruption of a heavy-current may safely take place, in which any burnirig of main contacts is avoided.

Gen "ally the invention comprises. a contact mechan m wh includes a pair of main contacts and a ir of auxiliary contacts which auxilia y con acts open only after opening of main contacts has been completed, all'arcing ta i g lace between the auxiliary contacts. ihe aux liary contacts are enclosed in an arcing or explosion chamber which is divided into compartments the individual compartments being closed automatically as the arcing between the at iary contacts progresses andthe arcing path becomes longer. Preferablythe con-- tacts and auxiliary contacts are disposed within a unitary housing formed of suitable insulating material.

Among the objects of the invention, is the provision oi circuit breaker contact of this character in which all arcing accompanying the interruption or" a heavy current takes place between a pair of auxiliary contacts which, at the time of the current interruption, are en closed in a special arcing Or explosion chamber.

A further object of the inventiouis theprovision of a mechanism of this character invvhich the explosion chamber is partitioned into individual compartments.

Another object of the invention is the provision of means for automatically closing off and isolating the individual compartments of the arcing chamber so that the arc is positively extinguished.

Still another object of theinvention-isthe provision of telescopic spring means for preventing the opening of the auxiliary contacts until after the main contacts have opened.

Other and further objects will become apparout upon reading the following-specificationtogether with the accompanying drawing fforming a part hereof.

"Referring to the drawing, the single figure is a diagrammatic representation of an embodiment of the invention illustratively shown as a sectional view in elevation.

In the drawing, a movable main contact !'is shaped as a pointed rodand is mcvablydisposed within a chamber 2 of a housing which is made of suitable insulating material. The movable contact I is shown in engagement with a stationary contact 3 indicated'by way of example as contact springs disposed within the chamber 2.

Immediately beneath the main contact chamber 2 is an auxiliary contact chamber i in-which all arcing and any incidental explosionstake place. Movably disposed within 'the auxiliary contact pin 55 is held by an annular stationary spring 5,,thus requiring a predetermined minimum force to effect withdrawal or" the head T of themovable contact pin from engagement with the stationary annular contact spring 6. Other forms of auxiliary stationary contact may be used instead of the annular contact spring ii, provided there is a predetermined m1" .mum force required to effect disengagement or the movable auxiliarycontact from the stationary auxiliary contact.

The auxiliary contact chamber s is provided with an intermediate wall 5 which divides the contact chamber t into two compartments. The auxiliary contact chamber i is also provided with an end wail The intermediate Wall 3 has an aperture 8 therein and the end wall 5 has an aperture 9' therein through which the auxiliary contact pin 5 passes freely.

The auxiliary contact pin 5 is secured through a telescopic spring unit it to the main movable contact supporting member Ii. After a predetermined movement of the main movable contact supporting member Ii toward the left as viewed in the drawing, a sufficient force is produced by compression of the helical springs in the telescopic spring unit It to eiifect disengagement of the movable auxiliary contact pin ii from the stationary annular auxiliary contact spring t.

Each of'the openings 8 andt' is provided with a self-closing flap l2 and'i'd, respectively. When the auxiliary contacts it are closed, the flaps i2 andlt are in the-positions indicated in solid lines, and when the auxiliary contacts 5-5 open, the flaps I2 and idswing through the arcs indicated in dotted lines to close the apermres B and 9, respectively. Instead of the gravity actuated flaps 12 and It, positively controlled closure means maybe utilized, such as rotary gates or doors, for example.

Th main contacts l.-i and the auxiliary contacts "5+6 are electrically connected in parallel.

The main movable contact supporting member II may be moved manually, or it may-be actuatedby any desired conventional and well known form of circuit breaker mechanism. This has-been i'llustratively indicated in the drawing as'a vertically movable pin Hi which is moved downwardly to trip the breaker. Pin it engages a rotary-lever it which forces a horizontal pin l6 to'the-right against a compression springl'l.

,Arod-lii is pivoted tohorizontal pin as and is mechanically arranged'to actuate the tripping mechanismcf the circuit breaker which is of conventional construction and which has therefore been omitted from the drawin In operation, upon tripping of the breaker, the main contact-supporting member ii moves tothe left to the position indicated in dotted lines. In moving to the left the main contacts l-3 open immediately and a force tending to open the auxiliary contacts 5-6 is developed by compression of the springs within the telescopic spring unit Ill. The annular contact spring 6, however, holds the head I of auxiliary movable contact pin 5 until suificient force is developed within the telescopic spring unit to efiect disengagement of the head 1 from the annular spring 6. When this occurs, the auxiliary movable contact pin 5 is snapped rapidly to the left, and as it is withdrawn successively through the apertures 8 and 9' in the walls 8 and 9, respectively, the doors l2 and I3 swing to their closed positions. Closure of the doors I2 and I3 extinguishes the arc and seals off the arcing or explosion chamber 4, dividing it into two separate isolated compartments.

It should be noted that a plurality of arcing or explosion chambers may be provided if desired, and that each such chamber may be divided into three or more compartments instead of two, if this is deemed to be desirable.

Having thus described my invention, it will be apparent to those skilled in the art that many changes and modifications may be made in the details thereof without departing from the scope of the invention as defined in the appended claims.

I claim:

1. Circuit breaker mechanism of the class described, comprising: a main stationary contact; a main movable contact engageable with said main stationary contact; a main movable contact supporting member upon which said main movable contact is supported; an apertured arcing chamber; an auxiliary stationary contact disposed within said arcing chamber; an auxiliary movable contact connected with said main movable contact and freely movable through said aperture into and out of said arcing chamber for engagement with said auxiliary stationary contact; closure means responsive to withdrawal of said movable auxiliary contact from said arcing chamber for closing said aperture; and delaying means efiective during the opening of said main contacts for causing said auxiliary contacts to remain closed until after said main contacts have opened, said delaying means comprising spring means connecting said movable aux iliary contact to said supporting member, said two auxiliary contacts further comprising means for opposing the opening of said auxiliary contacts until a predetermined minimum force tending to open said auxiliary contacts has been produced in said spring means by movement of said supporting member.

2. Contact mechanism according to claim 1, wherein said spring means comprises a telescopic spring unit.

3. Contact mechanism according to claim 1, wherein said means for opposing the opening of said auxiliary contacts comprises a head portion of one of said auxiliary contacts in engagement with an annular spring portion of the other contact, said minimum force being required to withdraw said head from said annular spring.

4. Circuit breaker contact mechanism of the class described, comprising: a main stationary contact; a main movable contact engageable with said main stationary contact; an apertured arcing chamber; an auxiliary stationary contact disposed within said arcing chamber; an auxiliary movable contact connected with said main movable contact and freely movable through said aperture into and out of said arcing chamber for engagement with said auxiliary stationary contact; closure means responsive to withdrawal of said movable auxiliary contact from said arcing chamber for closing said aperture; an apertured partition within said arcing chamber dividing said chamber into a plurality of compartments, said movable auxiliary contact being freely movable through said partition aperture; closure means responsive to withdrawal of said movable auxiliary contact through said partition aperture to close said aperture and isolate said compartments from each other; and delaying means eifective during the opening of said main contacts for causing said auxiliary contacts to remain closed until after said main contacts have opened.

5. Circuit breaker contact mechanism of the class described, comprising: a main stationary contact; a main movable contact engageable with said main stationary contact; an apertured arcing chamber; an auxiliary stationary contact disposed within said arcing chamber; an auxiliary movable contact connected with said main movable contact and freely movable through said aperture into and out of said arcing chamber for engagement with said auxiliary stationary contact; a gravity actuated flap responsive to withdrawal of said movable auxiliary contact from said arcing chamber for closing said aperture; and delaying means effective during the opening of said main contacts for causing said auxiliary contacts to remain closed until after said main contacts have opened.

6. Circuit breaker contact mechanism of the class described, comprising: a main stationary contact; a main movable contact engageable with said main stationary contact; an apertured means effective during the opening of said main contacts for causing said auxiliary contacts to remain closed until after said main contacts have opened, said delaying means comprising pring means effective after opening of said main contacts and disposed to exert a force tending to open said auxiliary contacts, said force being sufficient to withdraw said head of said pin from said annular spring.

FRITZ DRIESCI-IER, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,393,344 Conrad Oct. 11, 1921 2,480,622 Warnock Aug. 30, 1949 FOREIGN PATENTS Number Country Date 389,882 Great Britain Mar. 30, 1933 430,452 Great Britain June 19, 1935