US3324429A - Pushbutton-controlled overload circuit breaker - Google Patents

Pushbutton-controlled overload circuit breaker Download PDF

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Publication number
US3324429A
US3324429A US500720A US50072065A US3324429A US 3324429 A US3324429 A US 3324429A US 500720 A US500720 A US 500720A US 50072065 A US50072065 A US 50072065A US 3324429 A US3324429 A US 3324429A
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US
United States
Prior art keywords
housing
contact bridge
circuit breaker
pawl
control lever
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
US500720A
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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 US3324429A publication Critical patent/US3324429A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • H01H73/48—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 both electrothermal and electromagnetic automatic release
    • H01H73/56—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 both electrothermal and electromagnetic automatic release reset by push-button, pull-knob or slide
    • 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
    • H01H73/02—Details
    • H01H73/04—Contacts
    • H01H73/045—Bridging contacts

Definitions

  • the present invention relates to a pushbutton-controlled overload circuit breaker which is provided with a thermal release and/ or an electromagnetic release and also with a trip-free release, and further with a contact bridge.
  • a pushbutton of this circuit breaker is being depressed and a control rod which is rigidly secured to the pushbutton is moved accordingly, a carrier member on the control rod moves the contact bridge to the on position in which the carrier member is disconnected from the contact bridge.
  • this overload circuit breaker has the disadvantage that, if an additional pressure is exerted upon the pushbutton when it is already depressed and the contact bridge is in its on position in which the contact pressure is produced by the cut-off spring which acts upon the pushbutton, this spring is compressed and thereby rendered-ineffective. Therefore, when the pushbutton is in this depressed position, the contact pressure is produced merely by the other spring which is adapted to effect the trip-free release of the circuit breaker. The carrier member on the control rod which is acted upon by this trip-free release spring is then likewise moved so that this spring is released to a certain extent and the contact pressure is thereby further reduced.
  • the overload circuit breaker according to the invention may therefore be employed especially for currents of high amperages.
  • Another object of the invention is to design such an overload circuit breaker so as to have very small outer dimensions even though it is intended for high amperages, and to be of a simple construction which may be easily manufactured and assembled.
  • a further object is to design the circuit breaker so that it may also be switched off by hand.
  • One important feature of the invention consists in mounting the contact bridge on a pivotable control level,
  • the pivot pin of which is slidable within the walls of the housing and adapted to be locked in a fixed position by a pivotable pawl when the contact bridge is in its on position.
  • this pawl When this pawl is in its locking position, it is braced on a release lever which may be pivoted to an inoperative position when an excess current occurs.
  • the control lever which is connected to the contact bridge is provided with a stop projection which, when the contact bridge is in its off position, is located within the area of motion of a carrier member which is mounted on the control rod which, in turn, is secured to the pushbutton. When the contact bridge is in its on position, this stop projection on the control lever is moved out of the area of motion of the carrier member.
  • the control lever is acted upon by a compression spring which, when the pivot pin of the control lever is locked by the pawl in a fixed position, produces the necessary contact pressure of the contact bridge and, when the pivot pin of the control lever is released by the pawl, moves the control lever together with the contact bridge to the olf position.
  • the control lever When the contact bridge is in the on position, the control lever is therefore located in a position in which its stop projection is outside of the area of motion of the carrier member on the control rod which is rigidly secured to the pushbutton. Therefore, if a further pressure is then exerted upon the pushbutton when the contact bridge is already in its on position, it will have no effect upon the control lever and thus also not upon the contact bridge and the contact pressure which is produced by the compression spring which acts upon the control lever. A change in the strength of the contact pressure which could occur in my previous circuit breaker as above referred to when the pushbutton was again depressed 'when the circuit breaker was already switched on can therefore not occur in the circuit breaker according to the present invention.
  • the compression spring which acts upon the control lever produces a contact pressure of a high constant strength. so that the contact-resistance between the contact bridge and the fixed contacts is very small and any excessive heating of the contacts is prevented and the contacts are therefore prevented from scorching and fusing together so that the entire circuit breaker will therefore be properly operative for a very long time. Since the control lever and thus the contact bridge cannot possibly be affected by the pushbutton or the carrier member when the contact bridge is in its on position, a trip-free release will be attained when the control lever is released by the pawl under the action of the compression spring which acts upon the control lever. Only relatively small forces are required to move the release lever to the position in which the pawl will no longer be supported thereon so that a trip-free release will then occur. These releasing forces may be so small because the pawl is merely braced on the release lever, preferably in a position vertical to the pivot axis of the release lever.
  • FIGURE 1 shows, partly in section, a side view of the circuit breaker according to the invention in the on position and with one part of the housing removed;
  • FIGURE 2 shows a detailed view of the pushbutton together with the control rod and the carrier member according to FIGURE 1;
  • FIGURE 3 shows a view of the same element as in FIGURE 2, but as seen from the left side thereof;
  • FIGURE 4 shows a view similar to FIGURE 1, but with the circuit breaker in the off position;
  • FIGURE 5 shows a view as seen in the direction of the arrow V in FIGURE 4;
  • FIGURE 6 shows a cross section which is taken in the direction perpendicular to the axis of the control lever, as seen from the left of FIGURE 4; while FIGURE 7 shows a perspective view of the right upper part of the circuit breaker according to FIGURE 4.
  • the overload circuit breaker comprises a housing of insulating material which consists of two separate parts, namely, the part 1 into which the switch elements are inserted and another similar part, not shown, which is secured to and covers the part 1. Both parts of the housing are provided with recesses in which the various switch elements are held in their proper positions relative to each other, and both parts are secured to each other by rivets, preferably tubular rivets, which are inserted into corresponding bores 2 in both parts of the housing.
  • the circuit breaker For connecting it to an electric circuit, the circuit breaker is provided with two terminal strips 3 and 4 and terminal screws 5 thereon.
  • the inner end of terminal strip 3 carries a fixed contact 6 which is operatively associated with a contact 7 on a contact bridge 8.
  • This contact bridge 8 has another contact 9 which, when the contact bridge is in its on position, as illustrated in FIG- URE 1, engages upon a fixed contact 10 on a connecting bar 11 which is secured by a screw 12 to the housing part 1.
  • This connecting bar 11 is bent three times at right angles and it is centrally slotted so that its front and rear parts are connected at their upper ends and together form a coil winding.
  • the front arm of the slotted bimetal strip 16 is soldered or welded at 17 to one arm 4 of the slotted terminal strip 4, the other arm 4" of which is bent toward the right and secured by a screw 18 to the housing part 1.
  • the slotted bar 11 and the slotted bimetal strip 16 form two coil windings through which the arm 20 of a magnet core 19 extends.
  • This core 19 has another arm 21 which is provided withan extension 22 which projects at a right angle from the arm 21 and extends across the entire width of bar 11 above the upper end thereof.
  • the left end of arm 20 of the magnet core 19 has an upwardly bent extension 23.
  • the magnetic circuit of core 19 may be closed almost entirely at the extensions 22 and 23 by an armature 24 which forms an arm of a release lever 26 which is pivotably mounted on a pin 25.
  • This release lever 26 has another arm 27 into which there is screwed a setscrew 28 which has a small knob 29 of insulating material which is acted upon by the bimetal strip 16 when the latter is bent toward the right from its position as shown in FIGURE 1.
  • the rear arm 30 of the release lever 26 has a shoulder 31 upon which an arm 33 of a pawl 32 engages when this pawl is in its locking position, as shown in FIGURE 1.
  • Pin 25 on which the release lever 26 is mounted carries a torsion spring'34, one arm 35 of which acts at 36 upon the pawl 32, while the other spring arm 37 acts upon the release lever 26.
  • This'torsion spring 34 tends to maintain the pawl 32 and the release lever 26 in the positions as shown in FIGURE 1.
  • pawl 32 is pivotably mounted on two rivets 38 at the inside of a metal frame 39 which is inserted into recesses of a corresponding shape in the two parts of the housing.
  • FIGURE 6 further indicates that the metal frame 39 and pawl 32 are U-shaped.
  • the two lateral parts of pawl 32 are provided with corresponding recesses 40 forming equal detents 41 and with guide edges 42 above these recesses and equal noselike projections 43 below them.
  • Recesses 40 are adapted to receives a pivot pin 44 for a control lever 45 which has likewise a U-shaped cross section.
  • This control lever 45 has an upper arm 46 which is acted upon by a compression spring 47, the lower end of which rests upon the. bottom 48 of a recess 49 in the housing part 1.
  • the ends of pivot pin 44 are slidable and guided within slots 50 in the metal frame 39, as may be seen particularly in FIGURE 6.
  • control lever 45 has corresponding bores in which short pivot pins 51 on a one-armed lever 52 are pivotable.
  • Lever 52 is pivotably connected by a pin 53 to the contact bridge 8.
  • contact bridge 8 is stamped so as to form a central rectangular or L-shaped part 54 which carries the contacts 7 and 9, and front and rear parts 54' which are partly separated by slots from the central part 54 and are bent in the direction opposite to the central part so that all three parts together form a bearing into which the pivot pin 53 may be inserted.
  • the opposite ends of pin 53 are slidable in corresponding grooves 55 in the two housing parts.
  • control lever 45 The two lateral parts of control lever 45 are provided with notches 56 constituting stop projections into which a pair of small lateral projections 58 on a carrier member 57 may engage during the downward movement of the latter when the switch mechanism is in its off position as illustrated in FIGURE 4.
  • the carrier member 57 is pivotably mounted by pivot pins 59 on a part 60 which is rigidly secured to the lower end of the control rod 62, and it is acted upon by a small compression spring 61 which tends to maintain it in the position as shown in full lines in FIGURE 2.
  • the two sides of part 60 carry projections 60' which are slidable i-n corresponding grooves 62' in the two parts of the housing so as to guide the control rod 62.
  • control rod 62 The upper end of the control rod 62 is rigidly secured to a pushbutton 63 which is guided within an externally threaded bushing 64 and is acted upon by a cut-off spring 65 which is wound around the control rod 62 and the lower end of which rests on an insulating washer 66 which is held on an inner flange 67 of the housing part 1.
  • Bushing 64 carries a nut 68 and a curved spring washer 69, and its lower end is riveted to a metal plate 70.
  • the outer ends of this plate 70 are provided with T-shaped projections 71 which, when inserted into corresponding recesses in the right upper edges of both parts of the housing as indicated in FIG- URE 7, secure this metal plate 70 rigidly to the housing when the two parts thereof are secured to each other.
  • Plate 70 is preferably separated from the upper side of the two housing parts by an insulating strip 72.
  • the pivot pin 44 of lever 45 thereby pivots the pawl 32 in the clockwise direction about its axis 38 and lever 45 lifts the contact bridge 8 so that its contacts 7 and 9 disengage from the fixed contacts 6 and 10 and the circuit within the circuit breaker is interrupted.
  • This movement of control lever 45 is supported by the cut-off spring 65 which maintains the surfaces 73 of the U- shaped carrier member 57 in engagement with the pivot pin 44 when the switch mechanism is in the on position according to FIGURE 1, and which becomes effective when pawl 32 is released by the release lever 26 sov that the carrier member 57 then moves the pivot pin 44 upwardly and pivots the pawl 32 in the clockwise direction.
  • the circut breaker according to the invention is to be switched off by hand, it is merely necessary to pull on the pushbutton 63 which is for this purpose provided with a flange 63'.
  • the upper laterally projecting surfaces 73 of the U-shaped carrier member 57 then engage upon the'pivot pin 44 of control lever 45. Since this pivot pin 44 is at this time locked in a fixed position by pawl 32, the carrier member 57 will be pivoted about the pivot pins 59 to the position as indicated in FIGURE 2. in dotand-clash lines.
  • the overload circuit breaker according to the invention has very small outer dimensions which are actually only one half of those as shown in the drawings. It may be employed for rated currents up to 100 amp., and for short-circuit currents at a direct voltage of 24 volts up to 10,000 amp., and for low-voltage direct current circuits and medium-voltage alternating current circuits up to approximately 500' volts.
  • An overload circuit breaker comprising a housing, switch element provided within said housing and including a control rod slidable longitudinally of itself within said housing, a pushbutton secured to one end of said control rod and projecting from said housing for moving said circuit breaker to the on position, a carrier member mounted on the other end of said control rod, a pivotable control lever having a pivot pin, formations on said housing guiding said pivot pin for slidable displacement laterally of its axis, a contact bridge mounted on said control lever and movable from an oil”: position to an on position and vice versa, a pawl pivotally mounted on said housing adjacent said formations and engageable with said pivot pin of said control lever to latch said pin in a fixed position when said contact bridge is in its on position, a release lever pivotally mounted in said housing and releasably engaging and maintaining said pawl in its latching position, excess current responsive means operable to pivot said release lever to its pawl releasing position, said control lever having
  • said release lever has two arms, an electromagnet having a magnet core and an armature for electromagnetically releasing the circuit breaker, one of said arms of said release lever forming said armature, and a setscrew screwed through the other arm, said setscrew having a head of insulating material, and a bimetal strip engageable with said head so as to pivot said release lever for effecting a thermal release of the circuit breaker.
  • said carrier member is pivotably mounted on said control rod, a spring acting upon said carrier member, said carrier member being pivoted against the action of said last spring by said pivot pin of said control lever when locked by said pawl and when said pushbutton is manually pulled outwardly of said housing, said carrier member, when being thus pivoted, acting upon said release lever so as to pivot the same and thereby to release the circuit breaker.
  • a pushbutton-actuated overload circuit breaker comprising a housing, a control rod slidable longitudinally of itself within said housing, a pushbutton on the outer end of said control rod, a carrier mounted on the inner end of said control rod, a pivotable switching lever having a pivot pin, formations on said housing extending in the direction of movement of said control rod and said pushbutton and guiding said pivot pin for slidable displacement laterally of its axis, a contact bridge having an articulated connection to said switching lever at a point on the latter spaced from its pivot axis, a pair of stationary contacts bridged by said contact bridge in the on position of said circuit breaker, a pawl pivotally mounted on said housing adjacent said formations and engageable with said pivot pin of said switching lever to latch said pin in a fixed position when said contact bridge is in its on position, a spring acting on said switching lever at a point thereon spaced from its pivot axis and maintaining the contact pressure between said contact bridge and said stationary contacts, said spring, upon release of the pivot pin

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Breakers (AREA)
  • Thermally Actuated Switches (AREA)
US500720A 1965-06-02 1965-10-22 Pushbutton-controlled overload circuit breaker Expired - Lifetime US3324429A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEE29441A DE1292728B (de) 1965-06-02 1965-06-02 Druckknopfbetaetigter UEberstromschalter

Publications (1)

Publication Number Publication Date
US3324429A true US3324429A (en) 1967-06-06

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Application Number Title Priority Date Filing Date
US500720A Expired - Lifetime US3324429A (en) 1965-06-02 1965-10-22 Pushbutton-controlled overload circuit breaker

Country Status (6)

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US (1) US3324429A (zh)
AT (1) AT266247B (zh)
CH (1) CH445620A (zh)
DE (1) DE1292728B (zh)
FR (1) FR1565317A (zh)
GB (1) GB1111205A (zh)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3451016A (en) * 1966-11-10 1969-06-17 Ellenberger & Poensgen Pushbutton-actuated overload circuit breaker
US3659235A (en) * 1967-08-23 1972-04-25 Siemens Ag Automatic electric switch
US3938065A (en) * 1973-07-31 1976-02-10 Ellenberger & Poensgen Gmbh Push-button operated bipolar faulty current protective switch
US3944954A (en) * 1973-11-23 1976-03-16 Ellenberger & Poensgen Gmbh Excess current switching device

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2895028A (en) * 1958-02-27 1959-07-14 Ellenberger Jakob Pushbutton-operated overload switch
US3096415A (en) * 1960-05-27 1963-07-02 Allen Bradley Co Relay
US3142737A (en) * 1960-09-09 1964-07-28 Wood Electric Corp Heat responsive wire circuit breaker

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2895028A (en) * 1958-02-27 1959-07-14 Ellenberger Jakob Pushbutton-operated overload switch
US3096415A (en) * 1960-05-27 1963-07-02 Allen Bradley Co Relay
US3142737A (en) * 1960-09-09 1964-07-28 Wood Electric Corp Heat responsive wire circuit breaker

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3451016A (en) * 1966-11-10 1969-06-17 Ellenberger & Poensgen Pushbutton-actuated overload circuit breaker
US3659235A (en) * 1967-08-23 1972-04-25 Siemens Ag Automatic electric switch
US3938065A (en) * 1973-07-31 1976-02-10 Ellenberger & Poensgen Gmbh Push-button operated bipolar faulty current protective switch
US3944954A (en) * 1973-11-23 1976-03-16 Ellenberger & Poensgen Gmbh Excess current switching device

Also Published As

Publication number Publication date
AT266247B (de) 1968-11-11
GB1111205A (en) 1968-04-24
DE1292728B (de) 1969-04-17
FR1565317A (zh) 1969-05-02
CH445620A (de) 1967-10-31

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