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US2710321A - Protective switch - Google Patents

Protective switch Download PDF

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Publication number
US2710321A
US2710321A US423739A US42373954A US2710321A US 2710321 A US2710321 A US 2710321A US 423739 A US423739 A US 423739A US 42373954 A US42373954 A US 42373954A US 2710321 A US2710321 A US 2710321A
Authority
US
United States
Prior art keywords
bridge
contacts
strips
base
bimetal
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
US423739A
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English (en)
Inventor
Ellenberger Jakob
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ellenberger and Poensgen GmbH
Original Assignee
Ellenberger and Poensgen GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Ellenberger and Poensgen GmbH filed Critical Ellenberger and Poensgen GmbH
Application granted granted Critical
Publication of US2710321A publication Critical patent/US2710321A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H73/00—Protective 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
    • H01H73/22—Protective 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 having electrothermal release and no other automatic release
    • H01H73/30—Protective 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 having electrothermal release and no other automatic release reset by push-button, pull-knob or slide

Definitions

  • the present invention relates to improvements in protective switches, and more particularly to multiple-pole switches for electric motors and other electric apparatus.
  • a feature of the invention consists in providing a multiple-pole protec 've switch of novel des fn and very small dimensions, in which a movable contact bridge is provided for each circuit, which is safely retained in thc onposition by a catch or detent on the movable end of a bimetal strip, and which is quickly released under spring pressure to interrupt the current if an overload occurs and the birnetal strips are bent oy the resulting heat, or if the temperat 1re in or around the switch should exceed certain value for any other reasons.
  • Another feature of the invention consists in providing the movable contact bridges and the opposed stationary contacts each on a common supporting element parallel to each other, and in mounting each switch element so as to be turned l80 relative to the adjacent elements.
  • Further features of the invention consist in mounting the individual switch elements, and especially the contact i bridges, adjacent each other on a common contact plate, and in providing all of the elements which effect the movement of such contact plate within the area of the switch base on which the stationary contacts are mounted.
  • Another feature of the invention consists in mounting the contact plate so as to be freely movable and without any special guiding means, and to prevent it from tilting under the pressure of the release spring by holding it at several points which are symmetrically arranged relative to the point of application of the release spring by detents mounted on the free or movable ends of bimetal strips.
  • Such freely movable mounting of the contact plate results in an extremely simple and compact design ol the entire switch, and an easy, reliable operation thereof at all times.
  • An additional feature ot the invention resulting from such compact design of the novel switch and the fact that it is made of heat resistant material consists in its application not merely for protecting an electrical machine or apparatus from overcurrents, but also from excessive heat, caused, for example, by overheated bearings or other reasor. in which event the circuit alter may be mounted in the immediate vicinity of the respective machine part to be controlled, for example, withithe housing of the electric motor.
  • the application of the new switch is not restricted to electric motors but it may also be used in any other place or be built into any other machine or apparatus, especially if a protective switch of very small dimensions is desired.
  • Fig. l shows a longitudinal section through a protective switch according to the invention, taken along line I-I of Fig. 2;
  • Fig. 2 shows a section through the switch taken along line II-H of Fig. l;
  • Fig. 3 is a top view upon the mounting strap and the contact plate
  • Fig. 4 is a top view upon the base plate and the contact clips thereon;
  • Fig. 5 is a top view of the entire switch in closed position
  • Fig. 6 is a side view of the switch with the front wall or" the cover removed for better illustration;
  • Fig. 7 is a diagrammatic illustration of the use of the switch as applied to a three-phase A. C. motor in star connection; while 8 is an illustration similar to Fig. 7 for a delta connection.
  • the base plate l preferably Consisting of ceramic material, carries on its upper surface the spring contact clips 3 and the bimetal strips 4, and on its lower surface the terminals S.
  • each of the bimetal strips d has coiled thereon a resistance wire 6 which terminates below the contact plate 7.
  • Spring clips T2 the lower end of the resistance coils 6, and the terminals 5 are electrically connected, as well as secured to base plate l, by bolts 2 which also support the bimetal strips 4 which, however, are electrically insulated therefrom.
  • each resistance coil e is connected to a lug with a detent thereon and mounted on the bimetal strip 4 which extends upwardly and beyond such lug or dere-nt 8 with its free end 9 passing through an aperture in an insulatingy plate 10.
  • Plate it is arranged so as to be freely movable and is prevented from sliding olf t'ne free ends 9 of the binietal strips 4 by a mounting strap il which, in turn, is secured to the base plate l and the upper part of which extends closely above the insulating plate l0.
  • the contact plate 7 has bolted thereon the Contact bridges i2 with downwardly projecting contact ngers i3 which are adapted to iit into, and engage with, the free ends of the spring clips 3,
  • the lateral studs ld extending downwardly from the contact plate 7 act as centering means for securing the coil springs l5.
  • the contact plate 7 has further rigidly and centrally mounted thereon a Control button L; which is forced upwardly by a coil spring i7 which rests on the upper surface or' the retaining strap ll.
  • the cover 1S is removably secured to the strap l1' by two screws i9 and has a central aperture for the control button 16, as well as a slide button 2t) with knurls 2l on one side and the symbol of an arrow on the other side, i, e. the side facing the control button i6.
  • the slide button 2l) is preferably made ot a single piece of material and secured to the cover i8 by means 0 a spring ring 23 so as to be laterally slidable thereon.
  • the same result may also be obtained by pushing the slide button Ztl in the direction shown by the arrow 22, i. e. toward the control button 16.
  • the lower, ngerlike projection 2S of the slide button thereby engages the edge of the insulating plate 1t) and bends the free ends 9 ot the bimetal strips 4, which are guided by the plate 1t), toward the lett in the same manner as if such bending were caused by heating the bimetal strips d.
  • the bimetal strips f:- are bent by being heated by the resistance coils 6 to disengage the detents 8 from the contact bridge 12 to release the plate '7 and disconnect the contacts 13 and 3, the current may not again be switched on until the temperature in or around the switch has returned to normal and the bimetal strips 4 have regained their normal position.
  • the adjacent contact elements For conning the adjacent contact elements within the smallest possible space, they preferably are turned 180 relative to each other. Also, it is advisable to malte both the base plate 1 as well as the contact plate 7 of ceramic material, and the insulating plate 19, used for manually disconnecting the switch, likewise of heat resistant materiat.
  • a multipie-pole protective switch comprising, in combination, a stationary base, stationary contacts mounted on said base, a bimetal strip for each circuit having one end mounted on said base, means for heating said bimetal strips, a detent carried on each of said bimetal strips near the free end thereof, a movable bridge element, contacts mounted on said element to cooperate with said stationary contacts, said movable and corresponding stationary contacts being turned 180 relative to the adjacent contacts, a spring tending to force said bridge and the contacts thereon to the off-position, resilient means for maintaining said bridge always substantially parallel with said base, means for depressing said bridge to engage the contacts thereon with the corresponding stationary contacts and simultaneously to engage said detents with said bridge to retain the same in the on-position, and for simultaneously connecting said heating means, each of said detents adapted to release said bridge when said bimetal strips are heated beyond a certain temperature and are thereby bent so as to disconnect said corresponding contacts under the pressure of said spring.
  • a multiple-pole protective switch comprising, in combination, a stationary base, stationary contacts on said base, a bimetal strip for each circuit mounted on said base, means for heating said bimetal strip, a detent on each of said bimetal strips near the free end thereof,
  • a movable bridge element contacts mounted on said element to cooperate with said stationary contacts, said movable and stationary contacts being turned 180 relative to the adjacent contacts, a central button for depressing said movable bridge to engage the contacts thereon with the corresponding stationary contacts and simultaneously to engage said detents with said bridge to retain the same in the ori-position, and for simultaneously connecting said heating means, said detents adapted to release said bridge when said bimetal strips are being heated beyond a certain temperature, a central spring tending to force said bridge and the contacts thereon to the oit-position, and a plurality of springs for maintaining said bridge always substantiaily parallel with said base.
  • a multiple-pole protective switch comprising, in combination, a stationary base, stationary contacts mounted on said base, a bimetal strip for each circuit mounted on said base, means mounted on said bimetal strips for heating the same, a detent on each of said bimetal strips, said strips having a free end extending upwardly and beyond said heating means and detents,
  • a movable Contact bridge element contacts mounted on said element to cooperate with said stationary contacts, resilient means tending to force said bridge and contacts thereon to the off-position and for maintaining said bridge always substantially parallel with said base, a central button for depressing said movable bridge to engage the contacts thereon with the corresponding stationary contacts and simultaneously to engage said heating means, said detents adapted to release said bridge when said bimetal strips are being heated beyond a certain temperature, an insulating plate having apertures, the free ends of said bimetal strips extending through said apertures so as to move freely in one direction when said strips are bent by being heated, and means for shifting said insulating plate to bend said strips to disengage said detents, release said bridge, and disconnect said contacts independently of said heating means.
  • a multiple-pole protective switch comprising, in combination, a stationary base, mounted on said base, a bimetal strip for each circuit mounted on said base, means mounted on said bimetal strips for heating the same, a detent on each of said bimetal strips, said strips having a free end extending upwardly and beyond said heating means and detents, a movable bridge element, contacts mounted on said bridge to cooperate with said stationary contacts, a central button for depressing said bridge to engage the contacts thereon with said corresponding stationary contacts and simultaneously for engaging said detents with said bridge to retain the same in the oil-position, and for simultaneously connecting said heating means, a central spring tending to force said bridge and the contacts thereon to the oi-position, a plurality of springs for maintaining said bridge always substantially parallel with said base, said detents adapted to release said bridge when said bimetal strips are being heated beyond a certain temperature, an insulating plate having apertures therein disposed above said bridge, the free ends of said bimetal strips extending through said apertures so as to
  • a multiple-pole protective switch comprising, in combination, a stationary base, stationary contacts mounted on said base, a bimetal strip for each circuit mounted on said base, means mounted on said bimetal strips for heating the same, a detent on each of said bimetal strips, said strips having a free end extending upwardly and beyond said heating means and detents, a movable bridge element, contacts mounted on said bridge to cooperate with said stationary contacts, a cover, a push button centrally mounted in said cover for depressing said bridge to engage the contacts thereon with the corresponding stationary contacts and simultaneously to engage said detents with said bridge to retain the same in the onposition, and for simultaneously connecting said heating means, a central spring mounted within said cover tending to force said bridge and the contacts thereon to the ott-position, a plurality of springs intermediate said base and said bridge for maintaining said bridge always substantially parallel with said base and also tending to force said bridge to the oi-position, said detents adapted to release said bridge When said bimetal strips are being heated beyond a
  • a multiple-pole protective switch comprising, in coinbination, a stationary base, stationary contacts mounted on said base, a bimetal strip for each circuit mounted on said base, means mounted on said bimetal strips for heating the same, a detent on each of said bimetal strips, said strips having a free and extending upwardly and beyond said heating means and detents, a movable bridge element, contacts mounted on said bridge to cooperate with said stationary contacts, a cover, a push button centrally mounted in said cover for depressing said movable bridge to engage the contacts thereon with the corresponding stationary contacts and simultaneously to engage said detents with said bridge to retain the same in the on-position, and for simultaneously connecting said heating means, a central spring mounted within said cover tending to force said bridge and the contacts thereon to the oil-position, a plurality of springs intermediate said base and said bridge for maintaining said bridge always substantially parallel with said base and also tending to force said bridge to the oil-position, said detent adapted to release said bridge when said bimetal strips are being heated beyond a
  • a multiple-pole protective switch comprising, in combination, a stationary base of ceramic material having apertures therein, stationary contacts mounted on said base and within said apertures, connecting terminals below said base and connected to said contacts, a bimetal strip for each circuit mounted on said base, a resistance coil, around each of said strips, one end of said coils being connected to said stationary contacts, a detent on each of said bimetal strips and connected to the other end of said resistance coil, said strips having a free end extending upwardly and beyond said resistance coils and detents, a cover for said switch mounted on said base, a bridge element of ceramic material Within said cover and movable relative to said base, contacts mounted on said bridge to cooperate with said stationary contacts, a push button centrally mounted in said cover for depressing said movable bridge to engage the contacts thereon with the corresponding stationary contacts and simultaneously to engage said detents with said bridge to retain the same in the on-position, and for simultaneously connecting said other end of said resistance coils to said movable contacts, a central spring mounted within said cover tend
  • a multiple-pole protective switch comprising, in combination, a stationary base of ceramic material hav ing apertures therein, stationary contacts mounted on said base and within said apertures, connecting terminals below said base and connected to said contacts, a bimetal strip for each circuit mounted on said base, a resistance coil around each of said strips, one end of said coils being connected to said stationary contacts, a detent on each of said bimetal strips and connected to the other end of said resistance coil, said strips having a free end extending upwardly and beyond said resistance coils and detents, a cover for said switch mounted on said base, a bridge element of ceramic material having glazed cam surfaces for leading detents within said cover and movable relative to said base, contacts mounted on said ridge to cooperate with said stationary contacts, a push button centrally mounted in said cover for depressing said movable bridge to engage the contacts thereon with the corresponding stationary contacts and simultaneously to engage said detents with said bridge to retain the same in the oit-position, and for simultaneously connecting said other end of said resistance coils to

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  • Thermally Actuated Switches (AREA)
  • Breakers (AREA)
US423739A 1953-04-21 1954-04-16 Protective switch Expired - Lifetime US2710321A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE324861X 1953-04-21

Publications (1)

Publication Number Publication Date
US2710321A true US2710321A (en) 1955-06-07

Family

ID=6182150

Family Applications (1)

Application Number Title Priority Date Filing Date
US423739A Expired - Lifetime US2710321A (en) 1953-04-21 1954-04-16 Protective switch

Country Status (5)

Country Link
US (1) US2710321A (ja)
BE (1) BE528272A (ja)
CH (1) CH324861A (ja)
FR (1) FR1097592A (ja)
GB (1) GB758558A (ja)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1060472B (de) * 1957-02-05 1959-07-02 Ellenberger & Poensgen Mehrpoliger Schutzschalter fuer Elektromotoren
US2984364A (en) * 1957-05-06 1961-05-16 Lamb Grays Harbor Co Inc Roll-over machine
US3031542A (en) * 1959-10-26 1962-04-24 Ellenberger & Poensgen Pushbutton operated overload switch

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3169410A (en) * 1961-09-18 1965-02-16 Gen Electric Actuating mechanisms

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2409917A (en) * 1943-02-26 1946-10-22 Gen Electric Circuit breaker
US2483646A (en) * 1948-01-02 1949-10-04 Kitman Julia Thermal circuit breaker
US2587162A (en) * 1950-01-05 1952-02-26 Mechanical Products Inc Circuit breaker with ambient temperature and shock compensation

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2409917A (en) * 1943-02-26 1946-10-22 Gen Electric Circuit breaker
US2483646A (en) * 1948-01-02 1949-10-04 Kitman Julia Thermal circuit breaker
US2587162A (en) * 1950-01-05 1952-02-26 Mechanical Products Inc Circuit breaker with ambient temperature and shock compensation

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1060472B (de) * 1957-02-05 1959-07-02 Ellenberger & Poensgen Mehrpoliger Schutzschalter fuer Elektromotoren
US2984364A (en) * 1957-05-06 1961-05-16 Lamb Grays Harbor Co Inc Roll-over machine
US3031542A (en) * 1959-10-26 1962-04-24 Ellenberger & Poensgen Pushbutton operated overload switch

Also Published As

Publication number Publication date
CH324861A (de) 1957-10-15
GB758558A (en) 1956-10-03
FR1097592A (fr) 1955-07-07
BE528272A (ja)

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