The field of the disclosure relates generally to circuit breakers and, more particularly, to circuit breakers including rotary handles.
Circuit breakers are often used to protect, in a residential, industrial, utility, or commercial environment, against overcurrent conditions, ground fault conditions, or other system anomalies that are undesirable and require the circuit breaker to interrupt the flow of current through the circuit breaker.
At least some known circuit breakers include an electrically insulative case that encloses at least a portion of the circuit breaker and inhibits current flowing to the exterior of the case. Typically, the case includes a door that allows access to the interior of the case. The door includes a handle that is used to open and close the door. However, access to the interior of the case during operation of the circuit breaker is a safety risk due to the electric current flowing through the circuit breaker. Accordingly, at least some circuit breakers include a handle that is linked to conductive components which interrupt the flow of current through the circuit breaker when the door is opened. In addition, some circuit breakers include interlock mechanisms that inhibit the door opening when the circuit breaker is on. However, some handles and interlock mechanisms operate inconsistently and/or fail. Moreover, the handles and interlock mechanisms increase the cost and time required to assemble the circuit breakers.
In one aspect, an electrically insulative case for a circuit breaker is provided. The electrically insulative case includes a door arranged to move between an opened position and a closed position. The electrically insulative case also includes a rack mechanism arranged to move between an ON position and an OFF position. The rack mechanism is arranged to actuate an operating switch of the circuit breaker such that a conductive path is closed when the rack mechanism is in the ON position and is open when the rack mechanism is in the OFF position. The electrically insulative case further includes an interlock arranged to selectively inhibit the door moving between the opened position and the closed position. The interlock includes a plunger and an engagement mechanism. The plunger is arranged to move between a locked position and an unlocked position. The door is inhibited from moving to the opened position when the plunger is in the locked position. The engagement mechanism is coupled to the plunger and is arranged to move between a first position in which the engagement mechanism is spaced from the rack mechanism and a second position in which the engagement mechanism is engaged with the rack mechanism. The plunger is arranged to move to the locked position when the engagement mechanism is in the second position and the rack mechanism is in the ON position.
In another aspect, a circuit breaker is provided. The circuit breaker includes a door arranged to move between an opened position and a closed position and an operating switch arranged to move between an ON position and an OFF position. A conductive path is closed when the operating switch is in the ON position and is open when the operating switch is in the OFF position. The circuit breaker also includes a gear train mechanism coupled to the operating switch. The gear train mechanism is arranged to induce the operating switch to move between the ON position and the OFF position. The circuit breaker further includes an interlock that is arranged to selectively inhibit the door from moving between the opened position and the closed position. The interlock includes a plunger and an engagement mechanism. The plunger is arranged to move between a locked position and an unlocked position. The door is inhibit from moving to the opened position when the plunger is in the locked position. The engagement mechanism is coupled to the plunger and is arranged to move between a first position in which the engagement mechanism is spaced from the gear train mechanism and a second position in which the engagement mechanism is engaged with the gear train mechanism. The plunger is arranged to move to the locked position when the engagement mechanism is in the second position and the operating switch is in the ON position.
In yet another aspect, a method of manufacturing a circuit breaker is provided. The method includes coupling a door to an electrically insulative case. The door is arranged to move between an opened position and a closed position. The method also includes coupling a handle to the door to enable an operator to move the door between the opened position and the closed position and coupling a gear train mechanism to the handle. The gear train mechanism includes a rack mechanism that is arranged to actuate an operating switch of the circuit breaker such that a conductive path is closed when the rack mechanism is in an ON position and is open when the rack mechanism is in an OFF position. The method further includes coupling a plunger to the door. The plunger is arranged to move between a locked position and an unlocked position. The door is inhibited from moving to the opened position when the plunger is in the locked position. The method also includes coupling an engagement mechanism to the plunger. The engagement mechanism arranged to move between a first position in which the engagement mechanism is spaced from the rack mechanism and a second position in which the engagement mechanism is engaged with the rack mechanism. The plunger is arranged to move to the locked position when the engagement mechanism is in the second position and the rack mechanism is in the ON position.
These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Unless otherwise indicated, the drawings provided herein are meant to illustrate features of embodiments of the disclosure. These features are believed to be applicable in a wide variety of systems including one or more embodiments of the disclosure. As such, the drawings are not meant to include all conventional features known by those of ordinary skill in the art to be required for the practice of the embodiments disclosed herein.
In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings.
The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.
“Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.
Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “substantially,” and “approximately,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise.
Exemplary embodiments of circuit breakers and methods of manufacturing circuit breakers are described herein. The circuit breakers generally include a handle that rotates relative to an electrically insulative case. The handle is coupled to a gear train mechanism, which includes a drive gear, a plurality of pinions, and a sliding rack. In some embodiments, the plurality of pinions are positioned within an outer circumference of the drive gear to reduce the space occupied by the gear train mechanism. The gear train mechanism translates the rotational movement of the handle into linear movement of the sliding rack. The sliding rack causes actuation of a switch of the circuit breaker. In some embodiments, the handle includes a visual indicator mechanism to indicate the operating status of the circuit breaker. In further embodiments, the circuit breaker includes an interlock that selectively engages a biasing mechanism. Also, in some embodiments, the circuit breaker includes a gear lock mechanism that directly engages a drive gear.
In the exemplary embodiment, indicator panel 124 is inhibited from rotating and indicator cover 126 moves with handle 112. Accordingly, the portion of indicator panel 124 that is visible through opening 128 changes as indicator cover 126 rotates with handle 112. In alternative embodiments, indicator panel 124 and/or indicator cover 126 move in any manner that enables indicator mechanism 122 to operate as described herein. For example, in some embodiments, indicator panel 124 moves and indicator cover 126 remains stationary.
Also, in the exemplary embodiment, the visible portion of indicator panel 124 includes indicators that are associated with positions of handle 112. Specifically, in the illustrated embodiment, indicator panel 124 includes an ON position indicator 130, an OFF position indicator 132, and a TRIP position indicator 134. In some embodiments, indicator panel 124 is colored. For example, in some embodiments, ON position indicator 130 is green, OFF position indicator 132 is red, and TRIP position indicator 134 is white. In alternative embodiments, indicator panel 124 includes any indicators that enable circuit breaker 100 to operate as described herein.
In reference to
In the exemplary embodiment, first pinion 156 includes teeth that engage teeth on engagement portion 166 of drive gear 154. Second pinion 158 includes teeth that engage the teeth of first pinion 156. Accordingly, rotation of drive gear 154 causes rotation of first pinion 156 and second pinion 158. In alternative embodiments, gear train mechanism 150 includes any pinions 156, 158 that enable circuit breaker 100 to operate as described herein. For example, in some embodiments, gear train mechanism 150 includes three or more pinions 156, 158.
In the exemplary embodiment, engagement portion 166 is a semicircle having a diameter 170. First pinion 156 and second pinion 158 are sized and positioned such that first pinion 156 and second pinion 158 are encompassed within the circumference of engagement portion 166 when first pinion 156 and second pinion 158 are engaged with engagement portion 166. As a result, gear train mechanism 150 has a reduced size. In alternative embodiments, drive gear 154, first pinion 156, and second pinion 158 are any size and shape that enable gear train mechanism 150 to operate as described herein.
In the exemplary embodiment, drive gear 154, first pinion 156, and second pinion 158 are rotatably coupled to gear train housing 162. Specifically, drive gear 154, first pinion 156, and second pinion 158 are supported on a mounting plate 172 by a plurality of pins 174. In alternative embodiments, drive gear 154, first pinion 156, and second pinion 158 are coupled to gear train housing 162 in any manner that enables circuit breaker 100 to operate as described herein. In further embodiments, gear train housing 162 is omitted.
Moreover, in the exemplary embodiment, second pinion 158 engages rack 160 such that rotation of second pinion 158 causes rack 160 to move linearly. In particular, teeth of second pinion 158 engage teeth of rack 160. Accordingly, when drive gear 154, first pinion 156, and second pinion 158 rotate, rack 160 moves linearly. Rack 160 moves between an ON position and an OFF position and is configured to engage a switch (not shown) of circuit breaker 100. In alternative embodiments, rack 160 moves in any manner that enables circuit breaker 100 to operate as described herein.
In reference to
In the exemplary embodiment, rack 160 is substantially rectangular and has a plurality of orthogonal sides. Toothed portion 186 and slide portion 188 are positioned on opposite sides of rack 160. Moreover, toothed portion 186 and slide portion 188 are substantially parallel and facilitate linear movement of rack 160 in response to rotation of pinions 156, 158. In alternative embodiments, rack 160 has any shape that enables rack 160 to operate as described herein.
In reference to
In the exemplary embodiment, plunger biasing member 198 biases plunger 196 towards the first position. In particular, plunger biasing member 198 extends between and is coupled to plunger 196 and gear train housing 162. Engagement mechanism 200 extends through an opening in plunger 196 and is movable between a first position and a second position. In the first position, engagement mechanism 200 is at least partially concealed in plunger 196 such that engagement mechanism 200 does not engage rack 160. In the second position, engagement mechanism 200 extends from plunger 196 and engages rack 160 when rack 160 is in the ON position. In alternative embodiments, interlock mechanism 194 includes any engagement mechanism 200 that enables circuit breaker 100 to operate as described herein.
Also, in the exemplary embodiment, gear train mechanism 150 further includes a biasing mechanism 202 to bias plunger 196 to the second position. Biasing member 202 is coupled to rack 160. Biasing member 202 is spaced from plunger 196 when rack 160 is in the OFF position and engages engagement mechanism 200 when engagement mechanism 200 is in the second position and rack 160 is in the ON position. Moreover, biasing mechanism 202 has a biasing force that is greater than the biasing force of plunger biasing member 198. Accordingly, biasing mechanism 202 biases plunger 196 to the second position when engagement mechanism 200 is in the second position and rack 160 is in the ON position. To manually override plunger 196, an operator applies a force to plunger 196 that is greater than the biasing force of biasing mechanism 202.
As shown in
Moreover, in the exemplary embodiment, engagement mechanism 200 is accessible through opening 204 in handle assembly 106 to allow an operator to move engagement mechanism 200 between the first position and the second position. In the exemplary embodiment, an operator moves engagement mechanism 200 by turning a screw. As a result, engagement mechanism 200 will engage biasing mechanism 202 and plunger 196 will move to the second position when rack 160 is in the ON position. In alternative embodiments, engagement mechanism 200 is positioned in any manner that enables circuit breaker 100 to operate as described herein.
Third portion 216 is coupled to fourth portion 218 such that third portion 216 and fourth portion 218 are free to move in the Z-direction relative to each other. Second resilient member 222 extends through third portion 216 and fourth portion 218 and provides a biasing force to resist movement of third portion 216 and fourth portion 218 in the Z-direction. Accordingly, third portion 216, fourth portion 218, and second resilient member 222 provide compensation for misalignment of drive shaft 152 in the Z-direction.
In the exemplary embodiment, first portion 212, second portion 214, third portion 216, and fourth portion 218 are coupled together by interlocking grooves and projections that allow sliding movement of first portion 212, second portion 214, third portion 216, and fourth portion 218 in the respective directions. In particular, first portion 212, second portion 214, and third portion 216 form tongue and groove joints. Fourth portion 218 is received within third portion 216 and includes a pin 228 that extends through slots 230 in third portion 216. In alternative embodiments, first portion 212, second portion 214, third portion 216, and fourth portion 218 are coupled together in any manner that enables circuit breaker 100 to operate as described herein.
Also, in the exemplary embodiment, first lock pin 224 extends adjacent first portion 212 and first resilient member 220. Second lock pin 226 extends adjacent third portion 216 and second resilient member 222. First lock pin 224 and second lock pin 226 include a shoulder. In alternative embodiments, flexible coupling 208 includes any lock pin 224, 226 that enables circuit breaker 100 to operate as described herein.
In reference to
The circuit breakers described above generally include a handle that rotates relative to an electrically insulative case. The handle is coupled to a gear train mechanism, which includes a drive gear, a plurality of pinions, and a sliding rack. In some embodiments, the plurality of pinions are positioned within an outer circumference of the drive gear to reduce the space occupied by the gear train mechanism. The gear train mechanism translates the rotational movement of the handle into linear movement of the sliding rack. The sliding rack causes actuation of a switch of the circuit breaker. In some embodiments, the handle includes a visual indicator mechanism to indicate the operating status of the circuit breaker. In further embodiments, the circuit breaker includes an interlock that selectively engages a biasing mechanism. Also, in some embodiments, the circuit breaker includes a gear lock mechanism that directly engages a drive gear.
An exemplary technical effect of the methods, systems, and apparatus described herein includes at least one of: (a) reducing cost and time required to manufacture circuit breakers; (b) decreasing torque required to rotate circuit breaker handles; (c) increasing reliability of operating mechanisms of circuit breakers; (d) providing consistent indication of the status of circuit breakers; and (e) reducing the size of circuit breakers.
Exemplary embodiments of circuit breakers and methods of manufacturing circuit breakers are described above in detail. The circuit breakers and methods are not limited to the specific embodiments described herein but, rather, components of the circuit breakers and/or operations of the methods may be utilized independently and separately from other components and/or operations described herein. Further, the described components and/or operations may also be defined in, or used in combination with, other systems, methods, and/or devices, and are not limited to practice with only the circuit breakers and systems described herein.
The order of execution or performance of the operations in the embodiments of the disclosure illustrated and described herein is not essential, unless otherwise specified. That is, the operations may be performed in any order, unless otherwise specified, and embodiments of the disclosure may include additional or fewer operations than those disclosed herein. For example, it is contemplated that executing or performing a particular operation before, contemporaneously with, or after another operation is within the scope of aspects of the disclosure.
Although specific features of various embodiments of the disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.
This written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.