Circuit breakers with handle bearing pins
09620303 ยท 2017-04-11
Assignee
Inventors
Cpc classification
H01H71/505
ELECTRICITY
H01H71/528
ELECTRICITY
International classification
H01H75/00
ELECTRICITY
H01H77/00
ELECTRICITY
H01H71/50
ELECTRICITY
Abstract
Circuit breakers with handles having at least one handle bearing pin that contacts an upper end portion of a moving arm and allows the arm to rotate to OFF, ON and TRIP positions, typically about 90 degrees of rotation.
Claims
1. A circuit breaker comprising: a housing; a pivotable handle held by the housing; at least one pin held by the handle such that a longitudinal axis of the at least one pin is parallel to and offset from a pivot axis of the pivotable handle; and a moveable contact arm comprising a first end portion with a width and a laterally extending recess that is open in a direction facing the handle and that extends across the width of the first end portion of the contact arm and receives and contacts the at least one pin and provides a bearing surface for a handle/contact arm interface across the width of the first end portion of the moveable contact arm, wherein the contact arm is configured to move responsive to a force applied to the first end portion of the moveable contact arm by the pivotable handle through the at least one pin, wherein the at least one pin has an axially extending centerline that is offset from a pivot axis of the handle, wherein the handle has laterally spaced apart inwardly extending first and second sidewalls, one on each side of an arm receiving channel of the handle, and wherein the first sidewall has a segment with a length that is 1.5 to 5 times longer than the second sidewall.
2. The circuit breaker of claim 1, wherein the moveable contact arm has a second end portion opposing the first end portion, wherein the arm receiving channel in the handle has a length direction that is orthogonal to the at least one pin, with a pivot of the handle above the arm receiving channel and residing between opposing longitudinally spaced apart ends of the arm receiving channel and the second end portion comprises an electrical movable contact, the circuit breaker further comprising a stationary electrical contact held in the housing so as to selectively electrically engage the movable contact, and wherein the first end portion of the contact arm abuts and moves against the at least one pin that spans across a segment of the arm receiving channel as the contact arm and handle move between ON and OFF positions in the housing.
3. The circuit breaker of claim 1, wherein the circuit breaker has a TRIP operative position, wherein an exposed curved surface of the laterally extending recess of the first end portion of the arm moves against the at least one pin as the arm and handle move between the ON and OFF positions and the TRIP position, and wherein the laterally extending recess has a radius of curvature that corresponds to a radius of the at least one pin.
4. The circuit breaker of claim 1, wherein the at least one pin is a single pin that is physically secured only to the handle that provides the only direct moving contact between the arm and the handle.
5. The circuit breaker of claim 1, wherein the at least one pin is a single pin that has a length that is greater than the width of the first end portion of the contact arm, and wherein, with the circuit breaker oriented with the handle extending upward, the recess of the first end portion of the arm moves back and forth under the pin in the arm receiving channel while in continuous abutting contact with the pin.
6. The circuit breaker of claim 5, wherein the pin has an axially extending centerline that is longitudinally and laterally offset from the pivot axis of the handle, wherein the pin abuts the recess in the first end portion of the contact arm, wherein the pin is metallic and has an outer wall with a radius that is between 0.034 inches and about 0.045 inches, and wherein the handle is a molded polymeric body and the pin is unaffixed to the moveable contact arm.
7. The circuit breaker of claim 1, wherein the at least one pin resides in the laterally extending recess and is not affixed to the contact arm.
8. The circuit breaker of claim 1, wherein the at least one pin is a single pin, and wherein the recess in the moveable contact arm is arcuate with an open surface in a direction facing the pin.
9. The circuit breaker of claim 1, wherein the at least one pin is non-rotatably mounted to the handle.
10. The circuit breaker of claim 1, wherein the at least one pin is a single pin that is metallic, wherein the arm receiving channel has a length direction that is orthogonal to the laterally extending recess of the moveable contact arm, the arm receiving channel having a width that is about the same as the width of the upper end portion of the moveable contact arm, wherein the pin spans across the arm receiving channel and is held by laterally spaced apart and opposing shoulders of the handle to expose a medial segment of the pin that is longer than segments held by the laterally spaced apart shoulders, and wherein the medial segment of the pin resides in the recess of the moveable contact arm.
11. The circuit breaker of claim 1, wherein the at least one pin has a length that is between about 0.115 inches and about 0.328 inches and a body with an outer radius that is between about 0.06 inches and about 0.075 inches, and wherein the pin has a head that is recessed a distance in an aperture of the handle.
12. The circuit breaker of claim 2, wherein the at least one pin is a single pin that is only physically secured to the handle to span across the arm receiving channel.
13. The circuit breaker of claim 12, wherein the at least one pin is a single pin, wherein the pin aperture extends through a shoulder on one side of the arm receiving channel and a blind channel residing across from the shoulder on an opposing side of the arm receiving channel, and wherein, in position, the pin extends through the shoulder, across the arm receiving channel and into the blind channel.
14. The circuit breaker of claim 12, wherein the contact arm has an elongate concave shape with the upper end portion having a tip end, wherein the arm receiving channel extends across an entire bottom portion of the handle and has an open tip end that allows a tip end of the contact arm to retract and extend therefrom, wherein the pin resides closer to the tip end of the arm receiving channel relative to a longitudinally spaced apart opposing end of the arm receiving channel, and wherein the pivot of the handle resides between the open tip end of the arm receiving channel and the opposing end of the arm receiving channel.
15. A handle bearing assembly for a circuit breaker, comprising: a pivotable handle for a circuit breaker configured to rotate between ON and OFF positions, the handle having a lower portion comprising an arm receiving channel and at least one pin extending across the arm receiving channel, with the pin orthogonal to the arm receiving channel, the at least one pin configured to directly contact and cooperate with an arm providing a movable contact for the circuit breaker to define a bearing surface for a handle/contact arm interface, wherein the at least one pin is a single pin, wherein the pivotable handle has a pivot axis, wherein the pin has an axially extending centerline, wherein the pin centerline is offset from the pivot axis of the handle, wherein the handle has laterally spaced apart inwardly extending sidewalls, one on each side of the arm receiving channel, and wherein one of the sidewalls has a segment with a length that is 1.5 to 5 times longer than the other.
16. The handle bearing assembly of claim 15, wherein the arm receiving channel extends across an entire bottom portion of the handle and has a tip end that allows a tip end of the arm to retract and extend therefrom, wherein the at least one pin is held closer to the tip end of the arm receiving channel than an opposing longitudinally spaced apart end of the arm receiving channel.
17. The handle bearing assembly of claim 15, wherein the at least one pin is a single metallic pin and has a length that is between about 0.115 inches and about 0.328 inches and a radius that is between 0.034 inches and about 0.045 inches, wherein a longitudinally extending centerline of the pin is perpendicular to a face of the housing and resides longitudinally and laterally offset from a pivot axis of the handle, and wherein the pin has detectable wear of 0.001 inches or less after endurance testing carried out under UL 489 (BR2125) for 3000 repetitions.
18. The handle bearing assembly of claim 15, wherein, with the circuit breaker oriented with a front face of the housing being vertical, the first end portion of the arm has a pin channel with a recess which is open in a direction that faces the front face, wherein the handle holds the pin above the recess so that the pin resides in and contacts a curved laterally extending surface of the recess.
19. The handle bearing assembly of claim 15, wherein the at least one pin is a single pin that is held in a pin aperture in the handle with the exposed medial segment spanning across the arm receiving channel, wherein the pin aperture extends through a shoulder on one side of the arm receiving channel and a blind channel residing across from the shoulder on an opposing side of the arm receiving channel, and wherein, in position, the pin extends through the shoulder, across the arm receiving channel and into the blind channel.
20. The circuit breaker of claim 1, wherein the at least one pin is a single pin that comprises end portions with a greater size than a medial portion extending therebetween, and wherein the medial portion has a length that corresponds to the width of the first end portion of the contact arm and the medial portion is longer than each end portion.
21. The handle bearing assembly of claim 15, wherein the at least one pin comprises end portions with a greater size than the medial portion extending therebetween, and wherein the medial portion has a length that corresponds to a width of a first end portion of the arm and the medial portion is longer than each end portion.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
(16) 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).
(17) 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.
(18) 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.
(19) 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.
(20) The term about refers to numbers in a range of +/20% of the noted value.
(21) 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.
(22) 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.
(23) 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.
(24) The term self-retaining with respect to a handle bearing pin means that the pin engages a handle to lock into an axial and non-rotatable position and requires no other retention component.
(25) 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 or for turning power ON and OFF using a switch associated with a fuse. The circuit breaker can be for a motor starter unit or feeder unit, for example.
(26) Turning now to the figures,
(27) The pin 18 can be held by and/or in the handle 15 so that a longitudinal axis of the pin 18 is parallel to and offset from a pivot axis of the pivotable handle 15, which can provide a suitable torque lever arm.
(28) It is noted that not all circuit breakers 10 require a TRIP position (e.g., fused switches), so in some embodiments, the arm 25 and handle 15 can include only two operative positions, ON, OFF, rather than the noted ON, OFF and TRIP positions.
(29) As is well known, in the housing 10h, the circuit breaker 10 includes at least one arc chamber 20 having at least one arc chute 30 with arc plates 31 (
(30) As shown in
(31) The handle 15 can have an internal portion 15i with an arm receiving channel 17 that remains inside the housing 10h (
(32) The pin 18 can provide the only direct moving contact between the handle 15 and arm 25.
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(34) Still referring to
(35) Referring again to
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(37) A respective circuit breaker 10 can have a plurality of respective pairs of handles 15 and arms 25 as is also well known in the art.
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(39) As discussed above, the handle 15 can have an internal portion 15i with channel 17 (
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(41) The handle 15 with the pin 18 can be provided as a handle bearing assembly/subassembly.
(42) With the circuit breaker oriented with the handle 15 extending upward as shown, the arm 25 can be configured to have an elongate concave shape with the upper end portion 25e having a tip end 25t. The arm receiving channel 17 can extend across an entire bottom portion of the handle 15l and can have an open tip end 17t (
(43) The circuit breaker 10 can be configured to provide a stop 10s proximate the window 10w and extending inwardly to contact a handle ledge 19 that extends above the arm channel 17 when the handle 15 is in the ON position (
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(45) The handle arm channel 17 can have sidewalls 17w on both sides, one of which can be longer than the other, 17wl. The longer channel 17wl can extend down a distance that is between about 1.5 to about 10 times the length of the shorter sidewall, typically between about 2 to about 5, such as about 3.
(46) The arm receiving channel 17 can extend across an entire diameter of a bottom portion of the handle as shown in
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(49) As shown in
(50) In some embodiments, the line L can be drawn through the axially extending centerline of the pin 18, 18, 18 and the center of the pivot axis 15p with the angles of the line L being a as described above for the pin slot 16s in
(51) The pin 18, 18, 18 can be configured as a free floating or loose pin and is not required to be non-rotatable, in some embodiments.
(52) Combinations of the pin configurations or other surface features may also be used, alone or with adhesives or other securing or locking configurations.
(53) The at least one pin 18, 18, 18 may be electrically conductive or electrically non-conductive. The at least one pin 18, 18, 18 may comprise a metallic material or other suitable wear-resistant, sufficiently durable material. The at least one pin 18, 18, 18 may comprise a ceramic or fiber and/or glass reinforced resin. The at least one pin 18, 18, 18 may comprise a sufficiently rigid polymeric material. The at least one pin 18, 18, 18 may be a monolithic unitary member or comprise matable members or more than one material or a primary substrate with a coating, for example. The at least one pin 18, 18, 18 can be non-ferromagnetic.
(54) The pin 18, 18, 18 can have a length L that is between about 0.115 inches and about 0.328 inches, in some embodiments. The channel 17 can have a width W that is greater than the length of the pin 18, 18, 18, typically between about 1.1 to about 1.25, a width W that is about the same length of the pin 18, 18, 18 or a width W that is less than a length of the pin 18, 18, 18. If the pin 18, 18, 18 has a length that is less than a width of the channel 17, the length L is sufficient to extend across the channel 17 to engage a sidewall 17w on each side.
(55) The pin 18, 18 may be held by the handle 15 in other configurations, e.g., without requiring or outside of a channel 17.
(56) The handle 15 can be a monolithic molded polymeric member. The at least one pin 18, 18, 18, typically a single pin, can be any suitable material and can be selected to provide the durability and performance criteria associated with UL 489 endurance testing. The pin 18, 18, 18 can be attached to the handle 15 in any suitable manner. The pin 18, 18, 18 can be inserted into a pre-formed pin aperture 16. The pin 18, 18, 18 may be overmolded into the handle 15 without requiring a pre-formed pin aperture 16. The pin 18, 18, 18 may be ultrasonically welded and/or inserted into the handle 15. The pin 18, 18, 18 may be punched, pressed or otherwise physically inserted into the aperture 16.
(57) In some embodiments, the circuit breakers 10 can be DC circuit breakers, AC circuit breakers, or both AC and DC circuit breakers.
(58) The circuit breakers 10 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). The circuit breakers 10 may be high-rated miniature circuit breakers, e.g., above about 70 A in a compact package. However, it is contemplated that the circuit breakers 10 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.
(59) The circuit breakers 10 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 vehicles applications.
(60) As is known to those of skill in the art, Eaton Corporation has introduced a line of molded case circuit breakers (MCCBs) designed for commercial and utility scale photovoltaic (PV) systems. Used in solar combiner and inverter applications, Eaton PVGard circuit breakers are rated up to 600 amp at 1000 Vdc and can meet or exceed industry standards such as UL 489B, which requires rigorous testing to verify circuit protection that meets the specific requirements of PV systems. However, it is contemplated that the circuit breakers 10 can be used for various applications with corresponding voltage capacity/rating. In some particular embodiments, the circuit breaker 10 can be a high-rating miniature circuit breaker.
(61) The circuit breaker 10 may be particularly suitable for the BR circuit breakers with a thermal-magnetic trip curve that avoids nuisance tripping on mild overloads while reacting almost instantaneously to severe short-circuit conditions, such as the BRX circuit breaker from Eaton Corporation, Cleveland, Ohio.
(62) The handle bearing configuration provided by the pin 18, 18, 18 can remove a plastic wear point of the prior art configuration and reduce wear, eliminate or reduce wear and heat (friction induced) relative to the design shown in
(63) 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.