US2876311A - Bimetallic circuit breakers - Google Patents

Bimetallic circuit breakers Download PDF

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Publication number
US2876311A
US2876311A US610823A US61082356A US2876311A US 2876311 A US2876311 A US 2876311A US 610823 A US610823 A US 610823A US 61082356 A US61082356 A US 61082356A US 2876311 A US2876311 A US 2876311A
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United States
Prior art keywords
bimetallic
contact
switch
spring
housing
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Expired - Lifetime
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US610823A
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English (en)
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Ellenberger Jakob
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Individual
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Individual
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Publication of US2876311A publication Critical patent/US2876311A/en
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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H61/00—Electrothermal relays
    • H01H61/002—Structural combination of a time delay electrothermal relay with an electrothermal protective relay, e.g. a start relay

Definitions

  • the bimetallic circuit breaker is therefore provided with a heating coil through which the current ows.
  • circuit breakers of this .type as known prior to the present invention had considerable disadvantages. Such circuit breakers should interrupt the current within a period of two minutes if an overload of 100% occurs. However, at a temperature of 100 C. they should be able to withstand the maximum load for a period of four hours. Inorder to accomplish both purposes, it would be necessary to give the bimetallic element a very high initial tension, namely, up to approximately one kilogram. It is, however, practically impossible to build such circuit breakers since such a high' initial tension of the bimetallic element would require an excessive thickness thereof. However, such elements which still. respond properly deform already at a load of 600 grams.
  • This object is attained according to the invention by mounting the contact cooperating with the bimetallic element on a spring so that this contact will abut under the force of such spring against the contact mounted on the -bimetallic element. If the bimetallic element should bend, the contact on the spring will then at first follow the bending motion of the Ibimetallic element with the contacts being in a closed position until the spring comes to a point where its further movement will be prevented by a stop. Not until this time will it be possible that the two contacts between the bemetallic element and the spring can separate. It is thus possible to produce the same results as if the bimetallic element was given a high initial tension, and it will be ensured that the circuit breaker will always respond properly.
  • a circuit breaker of the type according to the invention has the further advantage that the stop for limiting the movement of the contact spring may be made adjustable, for example, by an adjusting screw so as to regulate the opening movement of the contacts in accordance with different circuit conditions.
  • the contact spring is made in a bent shape similar to a hairpin since this allows a convenient mounting of the 2 spring within the relatively small housing of the circuit breaker.
  • the circuit breaker as described is combined with a starter switch which s preferably likewise a bimetallic switch and provided with contacts at both opposite sides of the bimetallic strip.
  • the two switches according to the invention are preferably mounted within a single housing so as to save considerably in space and material.
  • the hairpin spring is then placed in a special recess provided in this housing.
  • the cover of the housing may also be provided with a riblike projection which tits upon the partition in the housing and thus separates the two switch elements entirely from each other and closes the housing.
  • the two opposite side walls thereof are preferably downwardly extended.
  • the terminal strips of the new bimetallic switch may extend from the housing either above the base and cover portions thereof, in which case the yrecesses for accommodating the strips are preferably provided in the base portion so as to permit the cover portion to be of a simple and inexpensive structure, or they may extend vertically upward and through the cover.
  • Fig. l shows a perspective view of the entire switch unit without its housing
  • Fig. 2 shows a top view of Fig. l, but with the switch elements mounted in a housing;
  • Fig. 3 shows a cross section taken along line III-III of Fig. 2;
  • Fig. 4 shows a cross section taken along line IV--IV of Fig. 2;
  • Fig. S shows a cross section taken along line V--V of Fig. 2, but with the cover ⁇ attached to the base;
  • Fig. 6 shows a perspective view of a closed housing with the terminal strips of the switches extending laterally therefrom;
  • Fig. 7 shows a view similar to Fig. 6, but with the terminal strips extending through the cover of the housing; while Fig. 8 shows a wiring diagram to illustrate one example of the application of the new switch unit.
  • a circuit breaker 1 which is responsive to both thermal and electrical overloads, and a switch 2 for controlling the auxiliary phase of a motor for starting the same are both mounted in the base portion 3 of a single housing.
  • the thermal overload switch 1 consists of a bimetallic st-rip 4 which carries a heating coil 5 which is separated from the bimetallic strip ⁇ by a layer of insulating material 6.
  • Current may be supplied to bimetallic strip 4 through a terminal strip 8 projecting from the housing and through a bridge member 7. The current then passes through a contact head 9 to a contact head 10 which is secured to a spring 11 of hairpin-shape which presses contact head 10 resliently against contact head 9 on the Patented Mar. 3,V 1959 vterminal strip 13, which, in turn, is connected t the one end of the spring 11, is adapted to engage to the otherpor free and contact-carrying end of this spring so as to limit the upward movement thereof.
  • Bridge 7 combines and connects the thermal overload switch 1 with the starting phase switch 2, and both switches 1 and 2 may be mounted side-by-side within base portion 3 of the housing.
  • Switch 2 likewise consists of a bimetallic strip 15 which carries a heating coil 17 and is separated therefrom by an insulating layer 16. It is likewise connected to terminal strip S. When connected to a circuit, the current then ows through the terminal strip 13 with a contact head 20 thereon.
  • the terminal strips 8, 13, and 1S extend horizontally, they may ⁇ also be bent at an angle and upwardly to extend through suitable slots in the cover 27, as shown in Fig. 7 by numerals 23, 24, and 25.
  • the base portion 3 of the housinv is also provided with a riblike projection 26 which serves as a partition to separate the two switches 1 and 2 from each other.
  • the cover 27 may be provided with a similar riblike projection 28 which will engage rib 26 when cover 27 is placed on base 3, so that the two switch units will then be completely separated and protected from each other.
  • Fig. 8 shows a wiring diagram to illustrate one particular example of the manner in which the new switch may be used.
  • numeral 29 indicates the main phase winding
  • numeral 3:0k the auxiliary or starter phase winding of a motor.
  • a circuit breaker comprising a base, a bimetallic element mounted at one of its ends on said base and having a contact, a heating coil mounted on said element, a leaf spring of hairpin shape biased in opening direction being secured at the free end of one of its legs to said base ⁇ and having a contact close to the free end of the other of its legs, said latter legbeing free to reciprocate towards and away from said one leg by dex-ing about the U-shaped portion of said spring, ,said latter contact being-disposed opposite the contact on said bime- .tallic element and adapted to resiliently engage the same when said element is deflected, an adjustable stop member mounted on said -base in the path of displacement 4of said free end of said leaf spring and adapted to be engaged by the same to limit movement of said leaf spring towards said element, and terminal means on said ibimetallic element and said spring for connecting the same in an electric circuit.
  • a switch unit comprising in combination a circuit breaker responsive to thermal and electric overloads in an electric circ-uit, a starter phase switch, a base, a biinetallic strip forming a heat-responsive organ in said latter switch mounted with one of its ends on said base and having on each side close to its opposite end one contact, a heating coil on said strip, two xed contacts on said base respectively opposite said strip contacts and arranged in such a manner that, in the one switch position, one of said xed contacts is engaged by one lof said contacts on said strip, while the other is disengaged, and in the other switch position, the other Contact is engaged and the one contact is disengaged, a bimetallic element forming a heat-responsive organ in said circuit breaker and being mounted at one of its ends on said base and having a contact, a' heating coil on said element, a leaf spring of hairpin shape biased in opening direction being secured at the free end of one of its legs to said base and having a contact close to the free end of the other of its legs
  • a switch unit according to claim 2 wherein said circuit breaker and said starter phase switch are housed in a common casing having separate compartments therefor.
  • a swtich unit according to claim 2, wherein said housing has two parts, one being associated with said base and the other forming a cover thereon, and wherein rib-like partitions in said two parts form said separate compartments, said partitions extending from respectively opposite inner walls of said parts to respectively engage one another at an intermediate plane.

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  • Thermally Actuated Switches (AREA)
  • Protection Of Generators And Motors (AREA)
US610823A 1956-07-19 1956-09-19 Bimetallic circuit breakers Expired - Lifetime US2876311A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEE12694A DE1091210B (de) 1956-07-19 1956-07-19 UEberstromschalter

Publications (1)

Publication Number Publication Date
US2876311A true US2876311A (en) 1959-03-03

Family

ID=7068394

Family Applications (2)

Application Number Title Priority Date Filing Date
US354822D Pending USB354822I5 (de) 1956-07-19
US610823A Expired - Lifetime US2876311A (en) 1956-07-19 1956-09-19 Bimetallic circuit breakers

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US354822D Pending USB354822I5 (de) 1956-07-19

Country Status (4)

Country Link
US (2) US2876311A (de)
DE (1) DE1091210B (de)
FR (1) FR1179033A (de)
GB (1) GB808715A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2986685A (en) * 1959-03-16 1961-05-30 Texas Instruments Inc Overload protective apparatus
US3243554A (en) * 1964-01-23 1966-03-29 Mechanical Products Inc Combination motor protector and start relay
US20080315984A1 (en) * 2004-11-10 2008-12-25 Abb Patent Gmbh Thermal Release

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1728092A (en) * 1927-03-31 1929-09-10 Monitor Controller Co Thermal relay
US2231463A (en) * 1937-08-13 1941-02-11 Emerson Electric Mfg Co Heat actuated switch
US2255672A (en) * 1938-07-01 1941-09-09 William C Mason Electrical control device
US2329119A (en) * 1940-07-05 1943-09-07 Edison Inc Thomas A Control system
US2352713A (en) * 1942-03-04 1944-07-04 Bryant Electric Co Fluorescent lamp starter
GB624038A (en) * 1947-03-18 1949-05-26 Basil Ernest Watkins Improvements in and relating to electric switches and circuit breakers
US2499208A (en) * 1948-04-21 1950-02-28 Gen Electric Thermally actuated switch
GB647659A (en) * 1948-01-19 1950-12-20 Lucas Ltd Joseph Improvements relating to switching means for vehicle lighting systems
US2673908A (en) * 1951-12-29 1954-03-30 Ite Circuit Breaker Ltd Instantaneous trip circuit breaker
FR1099705A (fr) * 1953-07-29 1955-09-08 Ellenberger & Poensgen Interrupteur à bilame
US2754392A (en) * 1952-11-04 1956-07-10 Benedik Fedor Circuit interrupter

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE299863C (de) *
DE319620C (de) * 1919-01-19 1920-03-12 Franklin Ind Ges M B H Selbstunterbrecher fuer elektrisch beheizte Geraete
NL25924C (de) * 1927-03-19
DE594744C (de) * 1930-03-08 1934-03-21 Siemens Schuckertwerke Akt Ges UEberstromwaermeausloeser
FR771685A (fr) * 1933-07-13 1934-10-13 Alsthom Cgee Nouvelle commande thermostatique pour interrupteurs électriques
DE684359C (de) * 1937-08-19 1939-11-27 Aeg UEberstromwaerme-Relais oder -Ausloeser
US2618721A (en) * 1945-06-16 1952-11-18 Gen Motors Corp Control with column loaded strip
DE851378C (de) * 1950-10-22 1952-10-02 August Wiemers Thermische Hilfsphasenabschaltung und thermischer UEberstrom-Schutz fuer Elektromotoren

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1728092A (en) * 1927-03-31 1929-09-10 Monitor Controller Co Thermal relay
US2231463A (en) * 1937-08-13 1941-02-11 Emerson Electric Mfg Co Heat actuated switch
US2255672A (en) * 1938-07-01 1941-09-09 William C Mason Electrical control device
US2329119A (en) * 1940-07-05 1943-09-07 Edison Inc Thomas A Control system
US2352713A (en) * 1942-03-04 1944-07-04 Bryant Electric Co Fluorescent lamp starter
GB624038A (en) * 1947-03-18 1949-05-26 Basil Ernest Watkins Improvements in and relating to electric switches and circuit breakers
GB647659A (en) * 1948-01-19 1950-12-20 Lucas Ltd Joseph Improvements relating to switching means for vehicle lighting systems
US2499208A (en) * 1948-04-21 1950-02-28 Gen Electric Thermally actuated switch
US2673908A (en) * 1951-12-29 1954-03-30 Ite Circuit Breaker Ltd Instantaneous trip circuit breaker
US2754392A (en) * 1952-11-04 1956-07-10 Benedik Fedor Circuit interrupter
FR1099705A (fr) * 1953-07-29 1955-09-08 Ellenberger & Poensgen Interrupteur à bilame

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2986685A (en) * 1959-03-16 1961-05-30 Texas Instruments Inc Overload protective apparatus
US3243554A (en) * 1964-01-23 1966-03-29 Mechanical Products Inc Combination motor protector and start relay
US20080315984A1 (en) * 2004-11-10 2008-12-25 Abb Patent Gmbh Thermal Release

Also Published As

Publication number Publication date
USB354822I5 (de)
DE1091210B (de) 1960-10-20
GB808715A (en) 1959-02-11
FR1179033A (fr) 1959-05-20

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