U.S. Pat. No. 6,396,370 (Leone), which is incorporated by reference herein in its entirety, allegedly recites that “[t]he circuit breaker (10) of the present invention is a molded case circuit breaker and includes a molded case (12) having a main cover (20), a first terminal (16) and a second terminal (16) mounted inside the case (12) with a stationary contact (44) electrically coupled to the first terminal (18) and a movable contact (42) electrically coupled to the second terminal (16). The movable contact (42) is coupled to an operating mechanism (40) which has a pivoting member (13) moveable between an ON position, an OFF position and a TRIPPED position. An intermediate latching mechanism (52) also is mounted in the housing (12) and is coupled to the operating mechanism (40). The intermediate latching mechanism (52) is selectively operated by a trip unit (60) which comprises a magnetic short circuit release and a thermal overload release. The trip unit (60) can be reconfigured by the addition of an inner yoke (67) nested between the flanges (71) of an outer yoke (66) and a second magnetic shield (70) can be attached to the outer yoke (66) to change the sensitivity of the trip unit (60) to the currents experienced by the circuit breaker. A particular embodiment of the circuit breaker (10) includes an interchangeable bi-metal (62) member of a copper alloy having a chemical composition of CDA #19400 and with an electrical conductivity of not more than 40% IACS.” See Abstract.
U.S. Pat. No. 5,608,367 (Zoller), which is incorporated by reference herein in its entirety, allegedly recites that “[i]n a molded case circuit breaker with an interchangeable thermalmagnetic trip unit, the C-shaped heater transformer core is permanently held in place in the casing by a load bus strap with the gap in the core facing the trip unit. When the interchangeable trip unit is inserted into the molded casing, a magnetically permeable member mounted in the trip unit is aligned in the gap in the heater transformer core. The bimetal of the trip unit is fixed at one end to an electrically conductive sleeve surrounding the magnetically permeable member and forming the secondary of the heater transformer. The length of the magnetically permeable member is selected to establish the current conditions at which the bimetal trips the circuit breaker. The bus strap has an off-set section forming a first shoulder against which one wall of the housing of the interchangeable trip unit seats, and a second shoulder against which a pole piece backed by the heater transformer core seats to fix a gap between the pole piece and the armature in the interchangeable trip unit providing the instantaneous magnetic trip function.” See Abstract.
U.S. Pat. No. 4,719,438 (Mrenna), which is incorporated by reference herein in its entirety, allegedly recites a “circuit breaker structure having a faster trip unit characterized by a circuit breaker operator and a trip unit comprising a coil, a core, and an armature, a flux concentrating plate spaced from and on the side of the armature opposite the core and for concentrating the magnetic field between the core and the armature, and a hold-back bracket having extending from and retaining the armature in a spaced position from the core so as to cause the magnetic field lines to flow through the bracketand the armature.” See Abstract.
Certain exemplary embodiments comprise a device comprising: a trip mechanism adapted to engage an operating mechanism of an alternating current circuit breaker, said trip mechanism comprising: a bi-metal element arranged lengthwise into a first end zone, a central zone, and a second end zone, a load bus coupled to said first zone, said second end zone adapted to engage an armature latch that is adapted to trip on operating mechanism of the circuit breaker; and an electromagnetic element coupled to the load bus.
A wide variety of potential embodiments will be more readily understood through the following detailed description of certain exemplary embodiments, with reference to the accompanying exemplary drawings in which:
When the following terms are used substantively herein, the accompanying definitions apply:
A general function of a circuit breaker can be to electrically engage and disengage a selected circuit from an electrical power supply. This function can occur by engaging and disengaging a pair of operating contacts for each phase of the circuit breaker. The circuit breaker can provide protection against persistent overcurrent conditions and/or against very high currents produced by short circuits. One of each pair of the operating contacts can be supported by a pivoting contact arm while the other operating contact can be substantially stationary. The contact arm can be pivoted by an operating mechanism such that the movable contact supported by the contact arm can be engaged and disengaged from the stationary contact.
There can be at least two modes by which the operating mechanism for the circuit breaker can disengage the operating contacts: the circuit breaker operating handle can be used to activate the operating mechanism; or a tripping mechanism, responsive to, for example, unacceptable levels of current carried by the circuit breaker, can be used to activate the operating mechanism. For many circuit breakers, the operating handle can be coupled to the operating mechanism such that when the tripping mechanism activates the operating mechanism to separate the contacts, the operating handle moves to a fault or tripped position.
To engage the operating contacts of the circuit breaker, the circuit breaker operating handle can be used to activate the operating mechanism such that the movable contact(s) engage the stationary contact(s). A motor coupled to the circuit breaker operating handle can also be used to engage or disengage the operating contacts. The motor can be remotely operated.
A typical residential circuit breaker can have a continuous current rating ranging from as low as 5 amps to as high as 50 amps. A typical industrial circuit breaker can have a continuous current rating ranging from as low as 15 amps to as high as 160 amps. The tripping mechanism for the breaker can comprise a thermal overload release and a magnetic short circuit release. The thermal overload release can operate by means of a bi-metalic element, in which current flowing through the conducting path of a circuit breaker can generate heat in the bi-metal element, which can cause the bi-metal to deflect and trip the breaker. The heat generated in the bi-metal is typically a function of the amount of current flowing through the bi-metal as well as the period of time that current is flowing. For a given range of current ratings, the bi-metal cross-section and related elements can be specifically selected for such current range resulting in a number of different circuit breakers for each current range.
In the event of current levels above the normal operating level of the thermal overload release, it can be desirable to trip the breaker without any intentional delay, as in the case of a short circuit in the protected circuit, therefore, an electromagnetic trip element is frequently used. In a short circuit condition, the higher amount of current flowing through the circuit breaker can activate a magnetic release that can trip the breaker in a much faster time than typically occurs with the bi-metal heating. It can be desirable to tune the magnetic trip elements so that the magnetic trip unit trips at lower short circuit currents at a lower continuous current rating and trips at a higher short circuit current at a higher continuous current rating. This can match the current tripping performance of the breaker with the typical equipment present downstream of the breaker on the load side of the circuit breaker.
There can be numerous methods to tune the magnetic trip unit for different trip currents. First, the armature spring force can be varied, by an adjustment or by changing springs, to change the resisting force on the armature, which can change the current required to trip the breaker. Second, the cross section of the steel in either the yoke, armature, or both can be adjusted to increase or decrease the amount of magnetic flux created by the short circuit current.
Certain exemplary embodiments comprise a device comprising: a trip mechanism adapted to engage an operating mechanism of an alternating current circuit breaker, said trip mechanism comprising: a bi-metal element arranged lengthwise into a first end zone, a central zone, and a second end zone, a load bus coupled to said first zone, said second end zone adapted to engage an armature latch that is adapted to trip on operating mechanism of the circuit breaker; and an electromagnetic element coupled to the load bus.
Substantially contained within body 1100 can be a trip mechanism 1400, which can comprise an electromagnetic element 1500 that can be magnetically, electrically, and/or mechanically coupled to a load bus 2100. Magnetic element 1500 can at least partially surround and/or be positioned substantially adjacent to a central zone of an elongated substantially planar bi-metal element 1600, which can also be electrically connected to load bus 2100 at location 2120. From the perspective of location 2120, and as perceived along the length of bi-metal element 1600 and/or along Y coordinate axis, bi-metal element 1600 can comprise a proximal end zone 1620, a central zone 1640, and a distal end zone 1660. Notably, distal end zone 1660 can be thinner, as measured along the X coordinate axis, than proximal end zone 1620 and central zone 1640. Also, distal end zone 1660 of bi-metal element 1600 can mechanically engage an armature latch 1700 (not shown in
The configuration of the end zones 5160 and 5260 and/or bi-metal elements 5100 and 5200 on bar 5300 can allow for:
Still other embodiments will become readily apparent to those skilled in this art from reading the above-recited detailed description and drawings of certain exemplary embodiments. It should be understood that numerous variations, modifications, and additional embodiments are possible, and accordingly, all such variations, modifications, and embodiments are to be regarded as being within the spirit and scope of this application. For example, regardless of the content of any portion (e.g., title, field, background, summary, abstract, drawing figure, etc.) of this application, unless clearly specified to the contrary, such as via an explicit definition, there is no requirement for the inclusion in any claim herein (or of any claim of any application claiming priority hereto) of any particular described or illustrated characteristic, function, activity, or element, any particular sequence of activities, or any particular interrelationship of elements. Moreover, any activity can be repeated, any activity can be performed by multiple entities, and/or any element can be duplicated. Further, any activity or element can be excluded, the sequence of activities can vary, and/or the interrelationship of elements can vary. Accordingly, the descriptions and drawings are to be regarded as illustrative in nature, and not as restrictive. Moreover, when any number or range is described herein, unless clearly stated otherwise, that number or range is approximate. When any range is described herein, unless clearly stated otherwise, that range includes all values therein and all subranges therein. Any information in any material (e.g., a United States patent, United States patent application, book, article, etc.) that has been incorporated by reference herein, is only incorporated by reference to the extent that no conflict exists between such information and the other statements and drawings set forth herein. In the event of such conflict, including a conflict that would render invalid any claim herein or seeking priority hereto, then any such conflicting information in such incorporated by reference material is specifically not incorporated by reference herein.
This application claims priority to pending U.S. Provisional Patent Application Ser. No. 60/598,552 (Attorney Docket No. 2004P12736US), filed Aug. 3, 2004.
Number | Date | Country | |
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60598552 | Aug 2004 | US |