Various exemplary embodiments relate to a high voltage/high current air break switch that rotates about multiple axes to engage a distal electrical terminal.
High voltage/high current air break switches typically include an elongated conductive contact or “blade” that is locked or otherwise secured to a distal electrical terminal during operation to ensure that the components remain in contact. Relatively large forces must be established and overcome to move the blade into a locking position to assure a stable conductive connection.
Some previous designs provided blades that could be closed by exerting relatively low forces. In some of these designs, rotating an operating mechanism (e.g., and elongated shaft extending to the ground) would first cause the blade to pivot and enter the distal electrical terminal. Continued rotation of the operating mechanism would then pivot the blade about its longitudinal axis and into contact with the electrical terminal to establish the electrical connection.
These low-closing force switches are not without drawbacks, however. In particular, the blades of previous low-closing force switches are capable of pivoting about their longitudinal axis prematurely. There are two common ways in which this can occur. First, and when opening the switch, if the blade is rotated quickly and stopped suddenly, the momentum of the blade will overcome the force applied by springs to hold the blade in its open contact position (i.e., its rotational orientation about its longitudinal axis in which it does not contact the electrical terminal) and cause the blade to pivot about its longitudinal axis and stop in the closed contact position. Second, and when closing the switch, the blade may initially bounce off the distal electrical terminal and allow the blade to rotate about its longitudinal axis before it is properly seated in the electrical terminal. In both of these cases the switch cannot be subsequently closed using the operating mechanism.
Therefore, a need exists for an improved air break switch that addresses one or more of the above drawbacks of previous switch designs.
According to an exemplary embodiment, an electrical switch includes a jaw assembly electrically connected to a first electrical conductor, a housing assembly electrically connected to a second electrical conductor and a blade assembly fixedly attached to the housing assembly at a first end thereof. The blade assembly has an electrically conductive blade contact fixedly attached to a second end distal from the first end. Further, the housing assembly and the blade assembly pivot about a first axis to drive the blade contact into the jaw assembly to close the switch and the blade assembly is operable to rotate about a second axis perpendicular to the first axis only when the distal end of the blade assembly is seated in the jaw assembly.
According to another embodiment an electrical switch includes a blade assembly with a rocker assembly having a first rocker component disposed at a distal end of the blade assembly and a second rocker component disposed at the end of the blade assembly proximate a housing assembly. The second rocker component is activated to enable rotation of the blade assembly in response to the first rocker component being activated.
According to another embodiment an electrical switch includes a blade assembly with a rocker assembly having a first rocker component disposed at a distal end of the blade assembly and a second rocker component disposed at the end of the blade assembly proximate a housing assembly. The second rocker component is activated to enable rotation of the blade assembly in response to the first rocker component being activated.
According to another embodiment an electrical switch including a jaw assembly, a housing assembly, a blade assembly, and a blade catch. The jaw assembly is electrically connected to a first electrical conductor. The housing assembly is electrically connected to a second electrical conductor. The blade assembly is fixedly attached to said housing assembly at a first end thereof and having an electrically conductive blade contact fixedly attached to a second end distal from said first end. The housing assembly and said blade assembly pivot about a first axis to drive said blade contact into said jaw assembly to close said switch. The blade assembly is operable to rotate about a second axis perpendicular to said first axis only when said distal end of said blade assembly is seated in said jaw assembly. The blade catch is disposed on the distal end of said blade assembly and engaging said jaw assembly to maintain said switch in the closed position when said blade assembly is rotated about said second axis.
The aspects and features of various exemplary embodiments will be more apparent from the description of those exemplary embodiments taken with reference to the accompanying drawings, in which:
Referring first to
Referring to
Referring now to
The first electrical terminal 22 may also include a first arcing arm 32 (
Returning to
Rotating the operating mechanism 16 pivots the second insulator 34 about a vertical axis. As such, the operating mechanism 16 pivots the blade 40 from a closed blade position (
Referring now to
To facilitate the pivotal motion of the blade 40 described in the previous paragraph, the blade support 38 includes a toggle mechanism 46 (
The toggle lever 60 includes a pin 62 that extends away from the first electrical terminal 22. The pin 62 engages a slot 64 (
If the blade 40 is in the open blade position and the open contact position (i.e., the configuration shown in
A simple latching mechanism inhibits the blade 40 from returning directly to the open blade position (
To return the blade 40 to the open contact position and the open blade position, the operating mechanism 16 is pivoted in a counter-clockwise direction to pivot the toggle lever 60 (
In order to ensure the toggle mechanism 46 does not force the blade 40 to return to the closed contact position when the operating mechanism 16 is pivoted in a counter-clockwise direction, the spring-biased terminal contacts 28 preferably remain in engagement with the blade contacts 42 until the toggle mechanism 46 passes over center. That is, friction between the terminal contacts 28 and the blade contacts 42 holds the blade 40 in the closed blade position until the blade 40 pivots from the closed contact position and the toggle mechanism 46 passes over center. Conversely, if the terminal contacts 28 were to disengage the blade contacts 42 before the toggle mechanism 46 passed over center, the blade 40 would begin to pivot vertically due to motion of the operating mechanism 16, but the second toggle member 72 and the compression spring 76 would force the blade 40 to pivot back to the closed contact position.
The spring constant of the compression spring 76 may be selected to provide an appropriate torque threshold to be exceeded to pivot the blade 40 about its axis. An appropriate torque threshold is higher than the torque needed to pivot the blade 40 about the vertical axis but preferably not so high that an operator cannot easily apply the torque to the operating mechanism 16. Additionally, the housing bracket 78 may be adjustable (e.g., by turning fasteners 81) to vary the force applied by the second toggle member 72 to the first toggle member 66.
Referring now specifically
The blade 40 is attached internally to a blade end cap go. A proximal portion 92 of the blade end cap go is outwardly expandable to ensure that the blade end cap go and the blade 40 remain in contact and electrically connected. A distal portion 94 of the blade end cap go is surrounded and contacted by one or more current transfer springs 96. The current transfer springs 96 are disposed within a terminal support 98.
The terminal support 98 mounts a second electrical terminal 100 above the blade support housing 47. The second electrical terminal 100 includes a terminal mounting 102 that fixedly connects to the terminal support 98 via fasteners 104. The terminal mounting 102 pivotally supports a conductor contact 106 via a threaded connection 108. A compression spring 110 disposed within the terminal mounting 102 biases the conductor contact 106 to ensure the terminal mounting 102 and the conductor contact 106 remain in contact and electrically connected through the threaded connection 108. The conductor contact 106 is pivotable relative to the terminal mounting 102 via the threaded connection 108 to reduce stress on another electrical conductor, such as a transmission wire 112 (
Referring again to
The switch 10 may comprise appropriate materials recognized by those skilled in the art. For example, the blade 40 may comprise aluminum and the terminals 22 and 100 and the blade support 38 may comprise copper, silver-coated metals, or the like. The insulators 20 and 34 may comprise ceramics.
Referring now to
Unlike the embodiment described above, however, the blade support 38 does not support a second electrical terminal. Instead, a distal end 128 of the blade 40 extends away from the first electrical terminal 22 and toward a second electrical terminal 130 supported by a third insulator 132. Besides facing the opposite direction to receive the distal end 128 of the blade 40, the second electrical terminal 130 is generally similar to the first electrical terminal 22 (e.g., the second electrical terminal 130 includes terminal contacts 132 and a corona shield 134). Furthermore, the lock bracket 30 on the second electrical terminal 130 faces downward. This construction is as such because, as viewed in
For both embodiments described above, it should be apparent that the electrical conductors (e.g., transmission wires 26 and 112) connected to the first and second electrical terminals are selectively electrically connectable by engaging and disengaging the blade from the first electrical terminal (in the case of the first embodiment) or both terminals (in the case of the second embodiment). Furthermore, the toggle mechanism inhibits the blade from pivoting about its own axis before pivoting proximate the first electrical terminal or both of the electrical terminals.
Referring to
According to the embodiment shown in
Housing assembly 301, according to this embodiment, is an aluminum cylinder disposed above insulator 203 and encloses the mechanism components, discussed in greater detail below. A terminal pad assembly includes flange 303 which bolts to the housing and conductor contact 305 which threads onto flange 303. This creates a current path from the housing to the bus work leading up to the switch.
Referring to
On one end of the housing assembly 301 an indicator assembly 315 is disposed. The indicator assembly includes a visual indicator, such as sticker 314 with green and red stripes that wraps around the blade 320 and an aluminum casting 316 that mounts to the back of the housing. In the embodiment shown, blade 320 is a 2-inch aluminum tube that runs through the center of the housing 301. The blade carries current between the jaw assembly, discussed in greater detail below, and the housing assembly. Casting 316 has slots in it so that only one of the colors of the sticker 314 will be displayed at any one given time, for example, red when the switch is closed and green when the switch is open. For example, when blade 320 is rolled into the closed position, only the red portion of sticker 314 should be visible through the slots in casting 316. When blade 320 is rolled into the open position, only the green portion should be visible.
Referring to
A drive bolt 405, for example a ½″ bolt, runs through the first toggle mechanism 401 and the blade. As shown the head of drive bolt 405 sticks out the bottom of the housing. A nut (not shown), such as a Nylock nut, is threaded on the end of the bolt within first toggle member 401 to hold it in the housing.
Drive lever 406 is attached, for example using an additional bolt, to the rotator flange and drive bolt 405 runs through a hole in the drive lever. When the rotator assembly rotates, the drive lever rotates the drive bolt which then rotates the toggle mechanism inside the housing.
One end of a toggle mechanism spring 407 applies a force to the toggle mechanism along the axis of the blade forcing the respective teeth of first and second toggle members 401 and 403 to engage in either the full open or closed position. A spring plate 409 abuts against the opposite end of spring 407 and is adjustably moved using adjustment bolts 410, which protrude through the housing, to regulate the amount of preload applied to the spring.
Canted coil spring 411 conducts electric current from the blade to the housing. Coil 411 is disposed within a tight groove in the interior of the housing and squeezes against the blade, creating a low resistance connection between the blade and housing. Front bushing 413, and a similar rear bushing at the back of the housing (not shown), keep the blade concentric within the housing. A bug guard 415 is made of plastic and prevents insects and other small matter from entering the housing in the area proximate where drive bolt 405 enters the housing.
Referring to
Jaw support 501 mounts to the insulator, for example, using a 3-inch or 5-inch bolt circle. The jaw bracket 505 then mounts to the jaw support 501 using 3 jaw adjustment bolts 503. The components of the jaw assembly, in turn, mount to the jaw bracket. The three jaw adjustment bolts 503 are used to level the jaw bracket 505. The jaw is adjusted so that the blade assembly makes correct contact with the jaw assembly when opening and closing.
Referring to
Contact finger springs 513 create contact pressure between the contact fingers 507, 509 and the blade assembly 515. Contact pressure is desired for a low resistance connection. According to the embodiment shown, there is one contact finger spring 513 providing contact pressure for each respective contact finger.
Jaw bypass 517 is a sacrificial piece of conductive material that directs any arc from the blade to the jaw bracket. The jaw bypass 517 maintains contact with the blade assembly 515 until the switch is rolled to the closed position to prevent an arc between the blade assembly and the contact fingers.
As shown in
Referring to
Top and bottom blade contacts 705, located in this embodiment 180 degrees from each other, are positioned on the top and bottom of the blade, respectively, and make electrical contact with the contact fingers when the switch is rolled into the closed position in the jaw. Blade plug 707 is fastened in the end of the blade and provides a mounting surface for the blade arcing horn 709 as well as a means of preventing insects from entering the tube.
Arcing horn 709 is a sacrificial piece of conductive material that directs any arc from the blade to the jaw. More particularly, the blade arcing horn 709 maintains contact with the jaw bypass 719 until the switch is rolled into the closed position to prevent an arc between the blade contacts 705 and the top and bottom contact fingers 711, 713, respectively.
Referring to
Referring to
Referring to
The operation of closing and opening the switch will now be described. First, closing the switch will be described. The switch is considered open when the blade is not in contact with the jaw. At this point, both rocker pins 721, 731 are sticking out of the blade. The rocker pin 731 in the housing is sticking through the slot in the toggle mechanism. The blade is not able to roll and indicator 315 displays green, indicating the switch is open.
The switch is then operated by rotating the pivot as described above. The initial rotation directs the blade towards, and ultimately into, the jaw assembly. The blade then hits the blade bumper in the jaw and the blade bumper pushes the rocker pin 721 on the jaw end into the blade. The rocker shaft then pulls the rocker pin 731 in the housing out of the toggle mechanism slot allowing it to move freely.
Since, the blade is already hitting the jaw, the housing is no longer able to rotate. Only the bottom half of the rotator is able to rotate at this point. This results in the drive lever driving the drive bolt. When the drive lever is driven, the entire blade is urged in the rolling direction but in order for that to happen, the sliding portion of the toggle mechanism must be cleared. The rotation of the toggle mechanism creates a force that pushes the sliding portion out of the way which compresses the toggle mechanism spring. The force against the toggle mechanism helps prevent the blade from rolling when it is not in the jaw.
Referring to
The first 30 degrees of rotation is to roll the blade 30 degrees in the jaw.
Since, the blade latch is holding the blade in the jaw, the housing is unable to rotate during this initial rotation. The drive lever drives the blade and toggle mechanism in the reverse direction that it did in the closing.
Now, the opening operation is discussed. Once, the blade has been rolled by approximately 30 degrees, the blade is free to swing out of the jaw. When the blade leaves the jaw, the rocker pin 721 on the jaw end of the blade is pushed out of the blade by the rocker spring. This results in the rocker pin in the housing being pushed into the toggle mechanism slot. The rocker pin in the housing now holds the toggle mechanism which prevents the blade from the rolling when not in the jaw. As the blade is leaving the jaw, the whip keeper catches the whip and holds it. When the blade gets far enough away to prevent arcing, the whip keeper releases the loaded spring whip. The whip action can extinguish small arcs as can be found on shorter unloaded transmission lines.
A further embodiment is described in reference to
Rotator assembly 5 includes 2 pieces as well. Lower insulator plate 5a of the rotator assembly bolts directly to the insulator. For example, the lower insulator plate bolts to the insulator with a 3 inch bolt circle or a 5 inch bolt circle depending on the size of the switch and/or required stability. Upper insulator plate 5b of the rotator assembly is attached to lower insulator plate 5a using a 1¼″ bolt. In one embodiment the use of two sets of needle bearings allows the rotator assembly to move freely. The housing then mounts to the top of upper insulator plate 5b.
Rotator gasket 6 in this embodiment is a rubber gasket that mounts between the rotator assembly 5 and the housing 3. This prevents moisture from ingressing into the bearings.
Indicator assembly 7 also includes 2 pieces. Indicator 7a, such as a sticker, has green and red stripes that wraps around the blade. Cap 7b is an aluminum casting that mounts to the back of the housing. Cap 7b in the embodiment shown has slots in it so that only one of the colors of the indicator will show in each of the open and closed positions. When the blade is rolled in the closed position, only the red portion of the indicator is visible. When the blade is rolled in the open position, only the green portion is visible.
Blade 8 in the present embodiment is a 2 inch aluminum tube that runs through the center of the housing 3. The blade carries current between the jaw assembly (e.g.,
Referring to
With continued reference to
Drive lever 11 is bolted to the rotator (5a). The drive bolt runs through a hole in the drive lever. When the rotator assembly rotates, the drive lever rotates the drive bolt which then rotates the toggle mechanism (5a) inside the housing.
Toggle mechanism spring 12 applies a force to the toggle mechanism 9 forcing the teeth to the full open or closed position. Spring plate 13 adjusts the amount of preload that needs to be applied to spring 12. For example, spring plate 13 is adjusted by one or more bolts 13a protruding from the front of the housing.
Canted coil spring 14 conducts the current from the blade to the housing and is set in a very tight groove in the housing so that it squeezes the blade, creating a low resistance connection between the blade and housing. One or more bushings 15 keep the blade concentric with the housing. For example, there is a bushing on the front of the housing and through the back cover plate. Bug guard 16 is, for example, a plastic piece underneath the toggle mechanism (9a) that prevents insects from entering the housing.
Referring to
Contact fingers 20 are mounted to the jaw 18, for example, using a number of bolts 20a or other attachment device. When the blade is in the closed position, the fingers conduct the current from the blade assembly to the jaw. The jaw then conducts the current to the bus. For example, for a 1200 Amp switch there will be 4 fingers and for a 600 Amp switch there will be 2 fingers.
Contact finger springs 21 create contact pressure between the contact fingers and the blade assembly. The contact pressure is needed for a low resistance connection. In the embodiment shown, there is one contact finger spring for each contact finger. Jaw arc horn 22 is a sacrificial piece that directs the arc from the blade to the jaw. The jaw arc horn maintains contact with the blade assembly until the switch is rolled to the closed position to prevent an arc between the blade assembly and the contact fingers.
Referring to
Release pin ramp 25 is apiece bolted inside of the bottom of the jaw. It makes contact with the release pin as the blade enters the jaw and pushes the release pin up into the blade. Blade latch spring 26 is mounted to the back of the jaw and engages with the blade latch which is located on the blade assembly. The blade latch spring is adjustable so that it catches the blade regardless of the speed of operation.
Referring to
Blade plug 29 is fastened in the end of the blade. The blade plug provides a mounting surface for the blade arcing horn as well as a means of preventing insects from entering the tube. Blade arc horn 30 is a sacrificial piece that directs the arc from the blade to the jaw. The blade arc horn maintains contact with the jaw arc horn until the switch is rolled to the closed position to prevent an arc between the blade contacts and the contact fingers.
Referring to
Rocker pin 34 (
Referring to
Operation of a switch will now be described in reference to
The release pin ramp pushes the rocker pin on the jaw end into the blade. The rocker shaft then pulls the rocker pin in the housing out of the toggle mechanism slot allowing it to move freely. The blade is in the jaw but it is not closed yet. The last 30 degrees of rotation is used for rolling the blade. Since, the blade is already hitting the jaw, the housing is no longer able to rotate. Only the bottom half of the rotator is able to rotate at this point. This results in the drive lever driving the drive bolt. When the drive lever is driven, the entire blade wants to roll. In order for that to happen, the sliding portion of the toggle mechanism must be cleared. Referring to
The blade is rolled 30 degrees into the jaw. The blade latch (27,
The first 30 degrees of rotation is to roll the blade 30 degrees in the jaw. Since, the blade latch is holding the blade in the jaw, the housing is unable to rotate during this initial rotation. The drive lever drives the blade and toggle mechanism in the reverse direction that it did in the closing. Once, the blade has been rolled 30 degrees, the blade is free to swing out of the jaw. When the blade leaves the jaw, the rocker pin on the jaw end of the blade is pushed out of the blade by the rocker spring (33). This results in the rocker pin in the housing being pushed into the toggle mechanism slot. The rocker pin in the housing now holds the toggle mechanism which prevents the blade from the rolling when not in the jaw.
As the blade is leaving the jaw, the whip keeper catches the whip and holds it. When the blade gets far enough away to prevent arcing, the whip keeper releases the loaded spring whip. The whip action can extinguish small arcs as can be found on shorter unloaded transmission lines.
Exemplary embodiments of the application have been described in considerable detail. Many modifications and variations to these exemplary embodiments described will be apparent to a person of ordinary skill in the art. Therefore, the invention should not be limited to the embodiments described, but should be defined by the claims that follow.
As used in this application, the terms “front,” “rear,” “upper,” “lower,” “upwardly,” “downwardly,” and other orientational descriptors are intended to facilitate the description of the exemplary embodiments of the present application, and are not intended to limit the structure of the exemplary embodiments of the present application to any particular position or orientation. Terms of degree, such as “substantially” or “approximately” are understood by those of ordinary skill to refer to reasonable ranges outside of the given value, for example, general tolerances associated with manufacturing, assembly, and use of the described embodiments.
This application claims priority to U.S. patent application Ser. No. 17/036,044, filed Sep. 29, 2020, which claims priority to U.S. patent application Ser. No. 16/010,837, filed Jun. 18, 2018, which claims priority to U.S. patent application Ser. No. 15/293,552, filed Oct. 14, 2016, which claims priority to U.S. Provisional Application Ser. No. 62/241,183, filed Oct. 14, 2015 and U.S. Provisional Application Ser. No. 62/320,964, filed Apr. 11, 2016, the disclosures of which are incorporated herein by reference in their entirety and to which priority is claimed.
Number | Date | Country | |
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62320964 | Apr 2016 | US | |
62241183 | Oct 2015 | US |
Number | Date | Country | |
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Parent | 17036044 | Sep 2020 | US |
Child | 17872842 | US | |
Parent | 16010837 | Jun 2018 | US |
Child | 17036044 | US | |
Parent | 15293552 | Oct 2016 | US |
Child | 16010837 | US |