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
  • H01H73/02—Details
  • H01H73/04—Contacts
  • H01H73/045—Bridging contacts
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H1/00—Contacts
  • H01H1/12—Contacts characterised by the manner in which co-operating contacts engage
  • H01H1/14—Contacts characterised by the manner in which co-operating contacts engage by abutting
  • H01H1/20—Bridging contacts
  • H01H2001/2091—Bridging contacts having two pivotally and electrically connected halve bridges
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H77/00—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting
  • H01H77/02—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism
  • H01H77/10—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with electrodynamic opening
  • H01H77/102—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with electrodynamic opening characterised by special mounting of contact arm, allowing blow-off movement
  • H01H77/104—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with electrodynamic opening characterised by special mounting of contact arm, allowing blow-off movement with a stable blow-off position

Definitions

• the present invention relates to a circuit breaker and particularly to an automatic current limiting circuit breaker that has a system with double interruption in series with at least two arc quenching chambers for each pole.
• Low-voltage electrical systems characterized by high currents and power levels normally use specific devices provided with a system that ensures the nominal current required for the various users, the insertion and disconnection of the load, the protection of the loads against abnormal events such as overloading and short-circuits by automatically opening the circuit, and finally the disconnection of the protected circuit by opening the movable contacts with respect to the fixed contacts in order to achieve full isolation of the load with respect to the electric power source.
• These devices are commonly known as automatic power switches for use in low- voltage industrial systems. There are several industrial solutions for these devices.
• each pole is interrupted in two separate regions that are electrically in series to each other, so that each one is subjected to less mechanical and thermal stress.
• the second solution is based on a reduction of the tripping time, so as to prevent the presumed short-circuit current from reaching its maximum value.
• This is a solution that requires the path of the current to have a shape that triggers, in case of a short circuit, an electrodynamic phenomenon capable of positively contributing to the production of the mechanical thrust required to open the contacts. In some cases, the energy required is in fact several hundred newtons per meter.
• the aim of the present invention is to provide an automatic current limiting circuit breaker whose mechanism and operating principle are simplified with respect to the circuit breakers of the known art.
• an object of the present invention is to provide an automatic current limiting circuit breaker that improves the distribution of the mechanical loads supported by the movable contacts.
• an automatic current limiting circuit breaker which comprises an insulating enclosure that accommodates fixed contact means and movable contact means, actuation means for actuating said movable contact means between open-circuit conditions and closed-circuit conditions, and arc quenching means that comprise at least one first and one second arc quenching chamber which are mutually separate, the fixed contact means comprising at least one first and one second fixed contact, which are mutually spaced and positioned respectively adjacent to the first and second arc quenching chambers, the movable contact means comprising at least one first movable contact and one second movable contact, which are electrically series- connected and can move simultaneously between open-circuit and closed- circuit positions, characterized in that the movable contact means comprise a first contact arm and a second contact arm that have a first end at which the first movable contact and
• Figure 1 is a perspective view of an example of one of the poles of an automatic current limiting circuit breaker according to the invention
• Figure 2 is a perspective view of details of a pole of an automatic current limiting circuit breaker according to the invention
• Figure 3 is a partially sectional view of the same details of the pole of an automatic current limiting circuit breaker of Figure 2;
• FIG 4 is a partially sectional view of other details of a pole of an automatic current limiting circuit breaker according to the invention.
• the automatic current limiting circuit breaker according to the invention comprises an insulating enclosure 1, of which only a cutout view is shown.
• the enclosure 1 accommodates fixed contact means, generally designated by the reference numeral 10, and movable contact means, generally designated by the reference numeral 20.
• the circuit breaker also comprises actuation means for moving the movable contact means between an open-circuit condition (shown in dashed lines in Figures 3 and 4) and a closed- circuit condition.
• a detail of the actuation means is given in Figures 1 and 4, which show an example of kinematic actuation chain 30.
• the circuit breaker further comprises arc quenching means, constituted by two mutually separate arc quenching chambers; the arc quenching chambers are not shown in the figures for the sake of clarity.
• Figure 1 shows the seats 2 and 3 formed in the enclosure 1 and suitable to accommodate said arc quenching chambers.
• the fixed contact means 10 comprise a first fixed contact 11 and a second fixed contact 12, which are mutually spaced and arranged respectively adjacent to the first and second arc quenching chambers, at the seats 2 and 3.
• the movable contact means 20 comprise a first movable contact 21 and a second movable contact 22, which are electrically series-connected and can be moved simultaneously between open-circuit and closed-circuit positions.
• the movable contact means 20 furthermore comprise a first contact arm 23 and a second contact arm 24, which are constituted by two elongated conducting plates that have a first end, designated by the reference numerals 25 and 26 respectively, at which the first movable contact 21 and the second movable contact 22 are fixed.
• the second end which is designated by the reference numeral 27 for the first movable arm 23, whereas the end of the second movable arm 24 is not visible, is fixed to a common pivot 40 so that the two movable arms 23 and 24 are free to rotate about it.
• the common pivot 40 is therefore operatively connected to the actuation means in order to allow the movement of the movable contacts.
• the first and second contact arms 23 and 24 are mutually electrically series-connected by virtue of at least one flexible conductor.
• the electrical series connection can be provided by means of a pair of copper braids 51 and 52.
• the common pivot 40 is fixed to a plate 31 that is operatively connected to the actuation means.
• the plate 31 can slide freely in an appropriate space formed between the seats 2 and 3 of the arc quenching chambers.
• the first and second contact arms 23 and 24 are preferably operatively associated with elastic means that perform this function.
• the elastic means can be constituted for example by two springs 32 and 33 that are respectively associated with the first and second contact arms 23 and 24, for example proximate to their end that lies opposite the movable contact 20.
• connection of the movable contact parts to the actuation means can be performed for example by means of a coupling lever 34, one end of which is rigidly coupled to the pivot 40 while the other end is rigidly coupled to the kinematic chain 30.
• the reduced complexity of the kinematic system allows to reduce the overall space occupation of the units for an equal electrical performance and expected life.
• the automatic current limiting circuit breaker thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; all the details may further be replaced with other technically equivalent elements.
• the materials used, as well as the contingent shapes and dimensions may be any according to requirements and to the state of the art.

Landscapes

• Breakers (AREA)
• Control Of Eletrric Generators (AREA)
• Ignition Installations For Internal Combustion Engines (AREA)
• Remote Monitoring And Control Of Power-Distribution Networks (AREA)
• Arc-Extinguishing Devices That Are Switches (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=11446371

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (1)

Citations (2)

• 2000
  • 2000-12-29 IT IT2000MI002875A patent/IT1319707B1/it active
• 2001
  • 2001-12-12 EP EP01272646A patent/EP1346385B1/de not_active Expired - Lifetime
  • 2001-12-12 WO PCT/EP2001/014850 patent/WO2002054431A1/en active IP Right Grant
  • 2001-12-12 DE DE60129041T patent/DE60129041T2/de not_active Expired - Lifetime
  • 2001-12-12 ES ES01272646T patent/ES2287075T3/es not_active Expired - Lifetime
  • 2001-12-12 AT AT01272646T patent/ATE365373T1/de not_active IP Right Cessation
  • 2001-12-12 CN CNA018215440A patent/CN1484846A/zh active Pending

Patent Citations (2)

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