1. Field of the Invention
The present invention relates to a circuit interrupting apparatus and, more particularly, to a circuit interrupting apparatus for medium- and high-voltage circuit isolating devices having operations counters and methods of forming and using such circuit interrupting apparatus associated therewith.
2. Description of the Related Art
Circuit isolating devices such as fuse cutouts, disconnecting switches, and power fuses are adapted to be periodically opened to provide necessary service, such as for fuse replacement or service to power lines. Conventionally, such circuit isolating devices include a ring-like conducting part and a hook-like conducting part which are relatively movable between a contacting position to establish a closed circuit through the device and a separated position to establish an open circuit through the device.
When it is necessary to open the circuit isolating device when it is carrying load current, an arc is drawn between the two conducting parts, which is likely to damage any components which are contacted by the arc. Also, where other adjacent circuits are involved, there is a risk that the drawn arc may jump to another circuit, causing a fault in the other circuit. Still further, there is a risk that the drawn arc can jump an operator, causing some type of injury.
To minimize the risks and dangers associated with the opening of such circuit isolating devices, a specially designed portable circuit interrupting apparatus has been developed as described, for example, in U.S. Pat. No. 2,816,984 by Lindell titled “Circuit Interrupter Construction” and in U.S. Pat. No. 2,816,985 by Lindell titled “Circuit Interrupting Means.” This apparatus typically comprises a rod-like terminal which enters the ring-like conducting part of the isolating device and a second terminal which loops about the hook-like conducting part. The interrupting apparatus is mounted at the upper end of an elongated line pole.
In use, the operator initially lifts the apparatus to an elevated position adjacent the isolating device while holding the lower or proximal end of the line pole, and the operator then swings the interrupting apparatus into engagement with the isolating device so as to bring the two terminals of the interrupting apparatus into proper contact with the two conducting parts of the isolating device. The interrupting apparatus of the type described above, and as illustrated and described in the above-referenced patents, should be carefully manipulated during its initial engagement with the isolating device so that the two terminals properly engage the two conducting parts of the isolating device. This typically requires the hook engaging terminal of the interrupting apparatus to initially engage the hook-like conducting part of the isolating device. The interrupting apparatus is then swung laterally so that the ring engaging terminal of the interrupting apparatus enters the ring-like conducting part of the isolating device.
Upon then pulling downwardly on the line pole, the operator is able to separate the two conducting parts of the isolating device to open the circuit so that the current then flows through a shunt circuit which is located in the interior of the interrupting apparatus. The interrupting apparatus further has a shunt circuit interrupter which opens the shunt circuit inside the apparatus so that the resulting arc is confined to the interior of the apparatus. Next, the interrupting apparatus is disconnected from the two conducting parts of the isolating device. A resetting latch is then engaged to allow the interrupting apparatus to be reset for the next use.
Often it is desirable to keep track of the number of interrupting apparatus operations, and thus the number of circuit isolating devices serviced, in order to analyze operator productivity or to facilitate maintenance based on the number of operations rather than length of time the interrupting apparatus is in the field. It is, however, difficult to accurately keep track of the number of operations performed by each interrupting apparatus. It has been recognized that an operation counter can be used to count the number of operations. For example, U.S. Pat. No. 6,300,585, by Nicolai titled “Operation Counter for a Circuit Interrupter,” describes an operation counter used to count the number of operations of a circuit interrupter in order to determine the operating life of the circuit interrupter and to determine a maintenance schedule to be applied to the circuit interrupter. The operation counter is responsive to contact with an arc-suppressing member and is positioned on or within an exhaust control portion of a circuit interrupter. Applicants have recognized that counters such as that described, however, are prone to excessive wear because part of the counter mechanism is in contact with arc-interrupting components or shunt-interrupting circuits which are subject to the wear and tear or other forms of degradation caused by arcing resulting from the circuit interrupting operation. Applicants therefore also recognized a need for an interrupting apparatus which can count the number of operations performed by each circuit interrupting apparatus that does not require direct interface with shunt-interrupting circuit components. Additionally, there are many circuit interrupting apparatus deployed in the field which do not have an operation counter. Applicants also further recognized a need for an operation counter that can be easily and inexpensively retrofitted to existing circuit interrupting apparatus to provide a count of the number of operations performed by the operator on an isolating circuit device.
Additionally, though such counters can be used to show a possible representation of the wear and tear on the circuit interrupting apparatus, such counters record operations regardless of the amperage of the circuit being interrupted. Though operator productivity is not a function of the amperage of the circuits repaired by the operator and a rough representation of component fatigue can be deduced from a raw count of the number of operations, high amperage operations cause much more wear and erosion than medium amperage operations which cause more wear and erosion than low amperage operations. Applicants still further recognized a need for a counter that can record total operation counts along with operation counts related to various categories of amperage interrupted by the interrupting apparatus to be used to formulate a maintenance or inspection schedule.
In view of the foregoing, embodiments of the present invention advantageously provide an apparatus and methods related to formation and use of a circuit interrupting apparatus that provide the user the ability to count the number of circuit interruption events performed on circuit isolating devices. Advantageously, embodiments of the present invention also provide a circuit interrupting apparatus which includes a counter that can count the number of operations performed by each circuit interrupting apparatus that does not require direct interface with shunt interrupting circuit components. Advantageously, embodiments of the present invention also provides a counter and methods that can record total operation counts along with operation counts related to various categories of amperage interrupted by a circuit interrupting apparatus. Advantageously, an embodiment of the present invention provides an operation counter that can be easily and inexpensively retrofitted to existing circuit interrupting apparatus.
More particularly, an embodiment of the present invention provides a portable circuit interrupting apparatus which includes a main housing having a main housing body including a main housing body outer surface and a longitudinal axis. A sleeve having a sleeve main body including a sleeve main body outer surface is coaxially mounted within the main housing so as to be slidable between an extended position and a retracted position. A spring assembly biases the sleeve main body from between the extended position toward the retracted position such that unless pinned or otherwise held extended, the sleeve main body will retract.
The portable circuit interrupting apparatus also includes a shunting circuit assembly having a ring engaging terminal adapted to electrically connect to a ring-like conducting part of a circuit isolating device and a hook engaging terminal adapted to electrically connect to a hook-like conducting part of a circuit isolating device. A shunting circuit segment is connected between the ring engaging terminal and the hook engaging terminal and is positioned within the housing and sleeve to interrupt the electrical connection between the ring-like conducting part and hook-like conducting part in response to movement of the sleeve from the retracted position to the extended position. This hollows the arc caused by the circuit interruption to be maintained within the circuit interrupting apparatus.
The portable circuit interrupting apparatus also includes a reset plunger assembly, which includes a reset plunger, connected to a medial portion of the main housing body. The reset plunger is adapted to have at least portions thereof extend through a reset plunger opening positioned in the medial portion of the main sleeve body when in a non-reset and biased inward lock position to releasably lock the sleeve in the extended position. This allows the interrupting apparatus to obtain and maintain an electrical clearance between the ring engaging terminal and the hook engaging terminal when the ring engaging terminal and the hook engaging terminal engage a circuit isolating device and when the main sleeve body is positioned in the extended position. The reset plunger is also adapted to reset outwardly in response to outwardly biased pressure by a user and outward pressure from the main sleeve outer surface when the sleeve main body is in an at least partially retracted position.
The portable circuit interrupting apparatus further includes an operation counter assembly having an operation counter connected to the reset plunger and positioned to count a number of circuit interrupting operations of the circuit interrupting apparatus in response to movement of the reset plunger. The operation counter assembly can be manufactured with the circuit interrupting apparatus or retrofit to a pre-existing circuit apparatus. The operation counter can include a rotational counter incrementor to increment a count of the operation counter. A roll pin or other connection device can be connected to the reset plunger in order to engage a click-over lever. The click-over lever is situated between the rotational counter incrementor and the roll pin and can be either permanently or intermittently connected. The click-over lever can respond to longitudinal movement of the reset plunger in a first direction to reset the counter to enable the operation counter to increment and responds to longitudinal movement in a second direction to increment the operation counter when such movement occurs.
The operation counter assembly can also include a selection switch for selecting a plurality of categories of amperage range of values most closely associated with the circuit isolating device. The operation counter can separately record the operation count and associate the operation count with a category selected from the plurality of categories and can track a number of counts associated with each of the plurality of categories and display the number of counts associated with the category so selected. This provides the user the ability to develop maintenance schedules based on actual usage in both quantity and quality.
The present invention also includes methods of forming and using a circuit interrupting apparatus adapted to count a number of circuit interrupting operations. For example, according to an embodiment of the present invention, a method of forming the circuit interrupting apparatus includes providing an operation counter assembly having an operation counter housing containing an operation counter and an operation counter actuating switch. The operation counter housing has a housing back side opening adapted to interface with a reset plunger protruding through a main housing body outer surface of the circuit interrupting apparatus and an operation counter housing front side opening to allow passage of the reset plunger through the operation counter housing. The method also includes installing an operation counter actuating switch actuator to the reset plunger, and fastening the operation counter housing to the main housing body of the circuit interrupting apparatus.
According to an embodiment of the present invention, a method of using the circuit interrupting apparatus on a circuit isolating device includes positioning a reset plunger to extend through a reset plunger opening in a medial portion of a main sleeve body positioned within a main housing body of the circuit interrupting apparatus when the main sleeve body is positioned in an extended position. The method can also include engaging a hook-like conducting part of the circuit isolating device with a hook engaging terminal of the circuit interrupting apparatus adapted to electrically connect to the hook-like conducting part, and engaging a ring-like conducting part of the circuit isolating device with a ring engaging terminal of the circuit interrupting apparatus adapted to electrically connect to the ring-like conducting part of the circuit isolating device. The ring-like conducting part is relatively moveable between a contacting position to establish a closed circuit through the circuit isolating device and a separated position to establish an open circuit through the circuit isolating device and to extend the main sleeve body from within the main housing body of the circuit interrupting apparatus. Opening the circuit with the circuit interrupting apparatus provides the impetus for rerouting the current through the circuit interrupting apparatus. The method can further include extending at least portions of the reset plunger through the reset plunger opening in the medial portion of the main sleeve body in response to the positioning of the main sleeve body in the extended position, and incrementing an operation counter connected to the main body housing of the circuit interrupting apparatus upon and in response to extension of the at least portions of the reset plunger through the medial portion of the main sleeve body.
A circuit interrupting apparatus according to an embodiment of the present invention advantageously can be used for keeping track of the number of circuit interrupting operations of and thus the number of circuit isolating devices serviced. This can help facilitate maintenance based on the number of raw operations or an itemized account of operations based on the amperage interrupted rather than length of time the interrupting apparatus is in the field. Advantageously, in an embodiment of the present invention the operations counter is not exposed to exhaust gases during use and, due to the positioning, can be housed in a durable metal housing to improve durability and lessen the chance of damage to the counter. Advantageously, in embodiments of the present invention, an operations counter cannot be reset to provide for a continuous monitoring of the operations performed throughout the life of the interrupting apparatus. Advantageously, in embodiments of the present invention, an operations counter can be positioned to count each time the tool is reset; thus, it never comes in contact with any internal loadbreak mechanisms.
So that the manner in which the features, advantages and objects of the invention, as well as others which will become apparent are attained and can be understood in more detail, a more particular description of the invention briefly summarized above may be had by reference to the embodiment thereof which is illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the drawings illustrate only a preferred embodiment of the invention and is therefore not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.
The present invention will now be described more fully hereinafter with reference to the accompanying drawings which illustrate embodiments of the invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the illustrated 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. Like numbers refer to like elements throughout, and the prime notation, if used, indicates similar elements in alternative embodiments.
As illustrated in
Note, a circuit isolating device 10 of the disconnecting fuse type is indicated in
In more specific detail, as shown in
According to an embodiment of the present invention, as perhaps best shown in
A tubular cylinder 42 can be mounted to the exterior wall of the tubular housing 34, so as to be parallel to the longitudinal axis 35. The tubular cylinder 42 can, in turn, slidably mount a shuttle 44 in the interior thereof. As shown in
A ring engaging terminal 40 is mounted to the main housing 34 preferably in the manner as perhaps best shown in
In an embodiment of the present invention, the shuttle 44 also mounts a pivot pin 56 which extends parallel to and below the terminal 40. The pivot pin 56 extends through a plate 58 and pivotally supports a line pole connector arm 60. The connector arm 60 includes a mounting post 62 by which a line pole 63 can be fixed thereto. A spring 64 can be interconnected between the connector arm 60 and the plate 58, so as to limit the pivotal movement of the connector arm 60 about the axis of the pivot pin 56, and return the arm to a neutral position.
As shown in
As perhaps best shown in
As shown in
The reset plunger 76 is adapted to extend at least portions of the reset plunger 76 through the reset plunger opening 77 in the medial portion of the main body of sleeve 36 when in a non-reset and biased inward lock position to releasably lock the sleeve 36 in the extended position. This feature allows the circuit interrupting apparatus 32 to obtain and maintain an electrical clearance between the ring engaging terminal 40 and the hook engaging terminal 68 when the ring engaging terminal 40 and the hook engaging terminal 68 are connected to the circuit isolating device 10 and when the main body of sleeve 36 is positioned in the extended position. The sleeve 36 will be locked in its extended position, until the release plunger 76 is manually released (pulled), which permits the spring 38 to return the sleeve 36 to its retracted position. The reset plunger 76 is further adapted to reset outward responsive to outwardly biased pressure by the user and outward pressure from the main body outer surface 37 of sleeve 36 when in an at least partially retracted position.
As shown in
In an embodiment of the present invention, the operation counter 91 comprises a mechanical counter and either mechanical or electronic display device and a rotational counter incrementor 93 to increment a count of the operation counter 91. Use of mechanical counters around high-voltage power lines can be beneficial as they are not affected by electrical currents that can be generated in conductors moving with respect to electromagnetic fields generated by the high-voltage powerlines. The operation counter assembly 90 further includes a roll pin 95 connected to the reset plunger 76 and a click-over lever 97 connected between the rotational counter incrementor 93 and the roll pin 95. The operation counter 91 is responsive to longitudinal movement of the reset plunger 76 preferably in the outward direction to reset the operation counter 91 to enable the operation counter 91 to increment the count and responsive to longitudinal movement in an inward direction to actually increment the count displayed by the operation counter 91 when such longitudinal movement occurs. The reverse, however, can also be true. Advantageously, the operation counter 91 can also be configured such that it is non-resettable by a field operator in order to prevent inadvertent reset of the operation count. Thus, the count displayed can be a continuous running total spanning the lifetime of the circuit interrupting apparatus 32, if so configured.
The reset plunger 76 is preferably spring-loaded so that it pushes against the outer body surface 37 of sleeve 36 when the sleeve 36 is in the retracted position (
An alternative embodiment of the present invention, as shown in
In an embodiment of the present invention, the operations counter assembly 110 can also include a selection switch panel 117 having a plurality of selection switches for selecting a plurality of categories of amperage range of values most closely associated with the circuit isolating device 10. The operation counter 111 separately records the count and associates the count with a category selected from the plurality of categories and can track and display a number of counts associated with each of the plurality of categories along with the total number of operation counts. For example, the operation counter 111 can have user selectable switches or a single user selectable switch to select a high, medium, and/or low amperage servicing operation. Actuation of the reset plunger 76′ in view of the category selected can result in incrementing the selected category along with the total operation count.
In another embodiment of the present invention, as perhaps best shown in
Advantageously, also provided are methods for forming and using a circuit interrupting apparatus 32 including an operation counter such as operation counter 91 or 111. As perhaps best shown in
As perhaps best shown in
As perhaps best shown in
Continued downward movement of the line pole 63 causes the sleeve 36 to axially extend from the main housing 34 against the biasing force of the spring 38, and by reason of the arcuate movement of the terminal 40, the main housing 34 will pivot away from the connector arm 60 about the axis of the pivot pin 56. Reset plunger 76, positioned to extend through a reset plunger opening 77 in a medial portion of a main body of sleeve 36, slides down the main body outer surface 37 of sleeve 36 during such extension and until reaching reset plunger opening 77. When the sleeve 36 reaches this predetermined extension position, the spring 83 extends the reset plunger 76 through reset plunger opening 77, locking sleeve 36 in the extended position and incrementing the operation counter 91, 111. Correspondingly, the shunting circuit 74 is interrupted inside the housing 36 so as to protectively contain the resulting arc.
Note, the shuttle 44, if installed, will normally remain locked in the upper position due to the pin 48, as shown in
With the circuit interruption complete, the user releases the circuit interrupting apparatus 32 from the isolating device 10 and lowers it to the ground. The user then grasps or pulls on the plunger ring knob 85 which, absent the downward pull provided by the operator to extend the sleeve 36 from within the main body of main housing 34, allows the spring 38 to retract the sleeve 36 within the main housing 34. This retraction causes the reset plunger opening 77 in the main body of sleeve 36 to no longer align with the reset plunger 76, thus maintaining the reset plunger 76 in an outward position. If the shuttle 44 was configured such that pin 52 is engaged within opening 46, the user also retracts pin 52 to allow shuttle 44 to be repositioned by spring 45 in the top position.
In the drawings and specification, there have been disclosed a typical preferred embodiment of the invention, and although specific terms are employed, the terms are used in a descriptive sense only and not for purposes of limitation. The invention has been described in considerable detail with specific reference to these illustrated embodiments. It will be apparent, however, that various modifications and changes can be made within the spirit and scope of the invention as described in the foregoing specification and as defined in the attached claims. For example, the described electrical counter can be mechanically actuated or the described mechanical counter can have a plurality of displays.
Number | Name | Date | Kind |
---|---|---|---|
2816980 | Lindell | Dec 1957 | A |
2816984 | Lindell | Dec 1957 | A |
2816985 | Lindell | Dec 1957 | A |
3727019 | Harvey | Apr 1973 | A |
3958156 | Tjebben | May 1976 | A |
4277677 | Neher | Jul 1981 | A |
5502427 | Scherer et al. | Mar 1996 | A |
5650602 | Wood et al. | Jul 1997 | A |
5861595 | Wood et al. | Jan 1999 | A |
6300585 | Nicolai | Oct 2001 | B1 |
Number | Date | Country | |
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20050127040 A1 | Jun 2005 | US |