Circuit breakers with common trip cams and related trip cams
09613774 ยท 2017-04-04
Assignee
Inventors
Cpc classification
H01H71/1027
ELECTRICITY
H01H71/04
ELECTRICITY
International classification
H01H3/20
ELECTRICITY
Abstract
Circuit breakers with handles have common trip cams with an integrated spring and trip cam base. The integrated spring directly contacts the armature in lieu of having the trip cam base formed to do so thereby allowing the use of alternative trip cam base configurations and materials from conventional relatively expensive materials.
Claims
1. A circuit breaker comprising: a housing; a pivotable handle held by the housing; a moving contact arm held in the housing in communication with the handle; an armature held in the housing; a trip cam held in the housing, the trip cam comprising at least one spring with at least one segment that extends outward a distance from an axis of rotation of the trip cam to contact the armature; and a cradle in the housing in communication with the handle and the trip cam, wherein the at least one spring comprises a first arcuate segment that extends a first angular distance before merging into the at least one segment that extends outward a distance to contact the armature, wherein the at least one spring comprises a second arcuate segment that is spaced apart from the first arcuate segment and that extends a second angular distance, and wherein the second angular distance is greater than the first angular distance.
2. The circuit breaker of claim 1, wherein the trip cam comprises a trip cam base, and wherein the at least one spring is held by the trip cam base and the at least one segment comprises a leg that extends outward from the trip cam base to contact the armature.
3. The circuit breaker of claim 2, wherein the trip cam base has a first circular end segment, and wherein the leg has a primary portion that angles out away from the first circular end segment and merges into a free end portion that contacts the armature.
4. The circuit breaker of claim 2, wherein the leg has a free end, wherein the leg can flex side-to-side and/or front-to-back relative to the trip cam base to thereby accommodate tolerance variations.
5. The circuit breaker of claim 2, wherein the leg that has a primary portion that is straight and merges into a free end portion that extends substantially orthogonal to the primary portion of the leg, and wherein the leg is configured to be able to flex side-to-side and/or front-to-back relative to the trip cam base to engage the armature in the circuit breaker.
6. The circuit breaker of claim 1, wherein the trip cam comprises a trip earn base, wherein the at least one spring is held by the trip cam base, wherein the trip cam base has opposing circular end segments separated by a neck segment, wherein the second arcuate segment of at least one spring merges into an arm that extends away from the neck segment, wherein the arm cooperates with an operator mechanism in the housing to force the trip cam base to turn when the breaker trips, and wherein at least one of the circular end segments of the trip cam base comprises an open slot sized and configured to receive a link member for linking another trip cam of an adjacent pole of the circuit breaker.
7. The circuit breaker of claim 1, wherein the housing is configured as a plurality of adjacent housings forming multiple poles of the circuit breaker, each having a respective handle, moving contact arm and trip cam, wherein the trip cams each have opposing circular end segments and the at least one spring, and wherein adjacent circular end segments of neighboring housings are mechanically linked together so that when one pole of the circuit breaker trips a respective trip cam of that pole, the trip cam of that pole forces other linked trip cams to rotate so that all poles trip to thereby have a common trip function.
8. The circuit breaker of claim 1, wherein the trip cam has a trip cam base with laterally spaced apart opposing circular end segments, wherein at least one of the circular end segments comprises an open slot sized and configured to receive a link member for linking another trip cam of an adjacent pole of the circuit breaker, and wherein at least one of the circular end segments comprises a groove in an outer surface thereof that holds a segment of the at least one spring in position.
9. A circuit breaker comprising: a housing; a pivotable handle held by the housing; a moving contact arm held in the housing in communication with the handle; an armature held in the housing; a trip cam comprising a trip cam base held in the housing; a cradle in the housing in communication with the handle and the trip cam; and at least one spring held by the trip cam base comprising a leg that extends outward a distance from an outer surface of the trip cam base and is configured to contact the armature, wherein the trip cam base has opposing circular end segments separated by a neck segment, and wherein the at least one spring has a straight segment extending across the neck segment and at least one arcuate segment that extends about at least a portion of one of the circular end segments before merging into the leg.
10. A circuit breaker comprising: a housing; a pivotable handle held by the housing; a moving contact arm held in the housing in communication with the handle; an armature held in the housing; a trip cam held in the housing, the trip cam comprising at least one spring with a leg segment that extends outward a distance from an axis of rotation of the trip cam to contact the armature; and a cradle in the housing in communication with the handle and the trip cam, wherein the at least one spring comprises an arm that is laterally spaced apart from the leg, wherein the arm extends outward a distance from the axis of rotation of the trip cam, wherein the arm resides closer to the handle than the leg, and wherein the leg has a longer length than the arm.
11. The circuit breaker of claim 10, wherein the at least one spring comprises a first arcuate segment that extends about a first circular end segment of a trip cam base a first angular distance, wherein the at least one spring further comprises a second arcuate segment that extends about a second axially spaced apart circular end segment of the trip cam base a second angular distance, and wherein the second angular distance is greater than the first angular distance.
12. A circuit breaker comprising: a housing; a pivotable handle held by the housing; a moving contact arm held in the housing in communication with the handle; an armature held in the housing; a trip cam held in the housing, the trip cam comprising at least one spring with a leg segment that extends outward a distance from an axis of rotation of the trip cam to contact the armature; and a cradle in the housing in communication with the handle and the trip cam, wherein the leg segment has a free end, wherein the leg segment can flex side-to-side and/or front-to-back relative to the trip cam base to thereby accommodate tolerance variations, wherein the at least one spring is a single, continuous length wire with a preformed shape comprising a straight segment with opposing first and second ends, the first end of the straight segment merging into a first arcuate segment that merges into the leg segment, the second end of the straight segment merging into a second arcuate segment that merges into an arm segment.
13. A trip cam for a circuit breaker, comprising: a trip cam base having a neck separating a first end portion and a second end portion, the second end portion defining an arm that is sized and configured to cooperate with an operator mechanism to force the trip cam to turn when a circuit breaker trips; and at least one spring held on the trip cam base comprising a leg segment that extends off the trip cam base a distance sufficient to contact an armature in a circuit breaker, wherein the trip cam base has opposing first and second circular end segments separated by a neck segment, and wherein the at least one spring has a straight segment extending across the neck segment and at least one arcuate segment that extends about at least a portion of the first circular end segment before merging into the leg segment.
14. The trip cam of claim 13, wherein the leg segment has a primary portion that is straight that merges into a free end portion that extends substantially orthogonal to the primary portion of the leg segment, and wherein the leg segment is configured to be able to flex side-to-side and/or front-to-back relative to the trip cam base to engage an armature in the circuit breaker.
15. The trip cam of claim 13, wherein at least one of the first and second circular end segments comprises an open slot sized and configured to receive a link member for linking another trip cam of an adjacent pole of the circuit breaker.
16. The trip cam of claim 13, wherein the at least one spring is a single, continuous length wire with a preformed shape comprising the straight segment having opposing first and second ends, the first end of the straight segment merging into a first arcuate segment as the at least one arcuate segment that merges into the leg segment, the second end of the straight segment merging into a second arcuate segment that merges into an arm.
17. The trip earn of claim 13, wherein the at least one spring comprises a first arcuate segment as the at least one arcuate segment that extends about the first circular end segment of the trip cam base a first angular distance, wherein the at least one spring comprises a second arcuate segment that is spaced apart from the first arcuate segment and that extends about the second circular end segment of the trip cam base a second angular distance, and wherein the second angular distance is greater than the first angular distance.
18. A trip cam for a circuit breaker, comprising: a trip cam base having a neck separating opposing circular first and second end segments; and at least one spring held on the trip cam base comprising a leg segment that extends off the trip cam base a distance sufficient to contact an armature in a circuit breaker, wherein the at least one spring further comprises an arm that is spaced apart from the leg segment to reside adjacent the first end segment of the trip cam base and the leg segment resides adjacent the second end segment of the trip cam base, and wherein the leg segment has a longer length than the arm of the at least one spring.
19. A method of moving components of a circuit breaker upon a tripping event, comprising: upon a tripping event: automatically rotating a cradle to realign a mechanism pivot point to move a handle from an ON to a TRIPPED position and, simultaneously, the rotating cradle interacts with an arm of a trip cam base to force trip cam rotation, wherein (a) rotation of a trip cam spring leg in response to the forced trip cam rotation applies an additional force on the handle to assist in movement of the handle to the TRIPPED position and (b) rotation of the trip cam produces a likewise rotation of all adjacent trip cams that are linked so that respective trip cam spring legs of linked poles engage a respective armature and forcibly also trip corresponding mechanisms, wherein the trip cam spring legs extend from respective single, continuous length wires with a preformed shape comprising a straight segment with opposing first and second ends, the first end of the straight segment merging into a first arcuate segment that merges into the spring leg, the second end of the straight segment merging into a second arcuate segment that merges into an arm.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
(23) The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. Like numbers refer to like elements and different embodiments of like elements can be designated using a different number of superscript indicator apostrophes (e.g., 40, 40, 40, 40).
(24) In the drawings, the relative sizes of regions or features may be exaggerated for clarity. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
(25) It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
(26) Spatially relative terms, such as beneath, below, bottom, lower, above, upper and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as below or beneath other elements or features would then be oriented above the other elements or features. Thus, the exemplary term below can encompass orientations of above, below and behind. The device may be otherwise oriented (rotated 90 or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
(27) The term about refers to numbers in a range of +/20% of the noted value.
(28) As used herein, the singular forms a, an and the are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms includes, comprises, including and/or comprising, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being connected or coupled to another element, it can be directly connected or coupled to the other element or intervening elements may be present. As used herein, the term and/or includes any and all combinations of one or more of the associated listed items.
(29) The term non-ferromagnetic means that the noted component is substantially free of ferromagnetic materials so as to be suitable for use in the arc chamber (non-disruptive to the magnetic circuit) as will be known to those of skill in the art.
(30) Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
(31) The handle can be associated with a disconnect operator (e.g., an operating handle) connected to an assembly for opening and closing separable main contacts in a circuit breaker and/or for turning power ON and OFF. The circuit breaker can be for a motor starter unit or feeder unit, for example.
(32) Turning now to the figures,
(33) The leg 21 can be configured to flex in order to facilitate and/or guarantee necessary trip cam rotation of linked poles to assure the trip, as manufacturing tolerances and/or variations may mandate.
(34) The at least one spring 20 can have any suitable shape for its intended circuit breaker and can vary depending on the trip cam body and/or spacing of the trip cam body from internal cooperating components, such as an armature and/or cradle, for example.
(35) The at least one spring 20 can be shaped and configured to resiliently and/or flexibly clip and/or snap onto the trip cam base/body 10b so as to snugly reside on the trip cam base body 10b. Once on the trip cam body 10b and in correct position, it is held in place by the geometry and features of the spring 20 and/or trip cam base 10b. That is, for example, the straight segment 20s of the spring 20 can extend over a neck 10n of the trip cam body 10b and the two arcuate segments 20a, 20c then extend about the respective opposing circular end segments 10c thus inhibiting longitudinal and radial movement.
(36) Referring to
(37) The leg 21 can directly contact the armature 45 while the trip base body 10b remains spaced apart from the armature 45.
(38) The leg 21 can have a primary portion that is straight for a distance as it extends off the trip cam base 10b, then can merge into a free end portion 21e that extends substantially orthogonal to the primary portion of the leg. The leg 21 can be configured to be able to flex side-to-side and/or front-to-back relative to the trip cam base 10b to engage an armature in the circuit breaker and accommodate manufacturing and/or build tolerances.
(39) The at least one spring 20 can have a body that is a monolithic continuous length, pre-formed and self-supporting shape. That is, as shown in
(40) The at least one spring 20 may also optionally include an arm 22 that extends off the trip cam body 10b and resides closer to a front face F of the circuit breaker (closer to the handle 15) than the leg 21. The arm 22 may also have an end portion 22e that extends at an angle off the primary portion of the arm 22p. The end portion 22e can be a self-supporting free end portion and can be configured to bump, push or nudge a handle 15 in a define direction to thereby force the handle to a trip position, typically a bottom portion of the handle 15b, when the trip cam body 10b is turned (
(41) One or both of the ends 21e, 22e of the arm 22 or leg 22 can include a sleeve or cap to increase the contact force or surface area (not shown). The sleeve and/or cap can be conductive or non-conductive, but if used, preferably can withstand a high temperature environment.
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(44) As shown in
(45) In some embodiments, is between about 120 degrees to about 270 degrees, more typically between about 180 degrees and 250 degrees, such as about 180 degrees, about 185 degrees, about 190 degrees, about 195 degrees, about 200 degrees, about 200 degrees, about 205 degrees, about 210 degrees, about 215 degrees, about 220 degrees about 225 degrees, about 230 degrees, about 235 degrees, about 240 degrees, about 245 degrees and about 250 degrees.
(46) In some embodiments, is between about 45 degrees and about 180 degrees, typically between about 70 degrees and about 90 degrees, such as about 70 degrees, about 75 degrees, about 80 degrees, about 85 degrees, or about 90 degrees.
(47) The first arc segment 20a can turn and/or bend the leg 21 to extend off one side of the trip cam body 10b and the second (larger) arcuate segment 20c can turn and/or bend the arm 22 toward an opposing side of the trip cam body 10b. The arc segments 20a, 20c can be configured so that the arm 21 and leg 22 extend outward from circular axially spaced apart end portions 10c of the trip cam body 10b in directions that are substantially diametrically opposed.
(48) The arc segments 20a, 20c can have a radius R that corresponds with a radius of the outer diameter of the circular end segments 10c.
(49) The trip cam body 10b can optionally include an arm 12 that interacts with an operator mechanism 10m (
(50) The trip cam body 10b can also have a neck 10n that resides between the arm 12 and an opposing planar end portion 14. The planar end portion 14 can be configured to align with a window 100w in the housing when the breaker is tripped (
(51) As shown in
(52) The circular end segments 10c of the trip cam base 10b can include respective slots 11 that slidably receive an insert and/or link 23 for allowing multiple trip cam bodies 10b to be attached/linked together (
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(54) It is also noted that the link 23 may be provided as an integral component or feature of a respective trip cam base 10b rather than as an insert. Thus, the trip cam bases can be aligned so that a slot of one aligns and connects to an onboard/integral link of another (not shown).
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(57) As is well known, the circuit breaker 10 includes at least one arc chamber 200 which may optionally have at least one arc chute 30 with arc plates (
(58) As shown in
(59) The handle 15 can include an external portion 15e which can comprise a user actuator or input such as a lever, thumb or finger wheel or other suitable configuration.
(60) The handle 15 can have an internal portion 15i with an arm receiving channel 17 that remains inside the housing 100h (8A, 8B). The arm receiving channel 17 can receive the first (shown as the upper) end portion of the arm 25 and allows the arm 25 to move right to left through ON, OFF, TRIP positions.
(61) Referring again to
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(64) In some embodiments, the first (shown as the upper) end of the arm 25 is able to move relative to the handle 15 in the arm receiving channel 17 of the handle. Compare the position of the upper end of the arm 25 with the handle 15 in
(65) Referring to
(66) Upon a tripping event, the pivoting/rotating cradle 55 will realign the mechanism pivot points and spring such to produce motivation for the handle to move from the ON to TRIPPED position. Simultaneously, the rotating cradle 55 will interact with arm 12 of trip cam base to force cam rotation. The rotation of trip cam spring leg 22 accompanies the trip cam rotation, resulting in an additional force to be applied to the handle to assist in its movement to the TRIPPED position. Also, rotation of the trip cam can be configured to produce a likewise rotation of all adjacent cams that are linked, resulting in trip cam spring leg 21 of the linked poles to engage the armature and forcibly also trip these mechanisms.
(67) In some embodiments, the circuit breakers 100 can be DC circuit breakers, AC circuit breakers, or both AC and DC circuit breakers.
(68) The circuit breakers 100 can be rated for voltages between about 1 V to about 5000 volts (V) DC and/or may have current ratings from about 15 to about 2,500 Amperes (A). However, it is contemplated that the circuit breakers 100 and components thereof can be used for any voltage, current ranges and are not limited to any particular application as the circuit breakers can be used for a broad range of different uses.
(69) The circuit breakers 100 can be a bi-directional direct current (DC) molded case circuit breaker (MCCB). See, e.g., U.S. Pat. Nos. 5,131,504 and 8,222,983, the contents of which are hereby incorporated by reference as if recited in full herein. The DC MCCBs can be suitable for many uses such as data center, photovoltaic, and electric vehicle applications.
(70) The circuit breaker 100 may be particularly suitable for residential MCBs with 70 Amp and above ratings.
(71) The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the invention.