The present disclosure relates generally to a switching device. More specifically, the present disclosure relates to an interlocking mechanism for conditionally allowing operation of the switching device.
Switching devices, such as, electrical switches, are used to control flow of electrical current. For example, electrical switches form an electrical connection allowing flow of current when switched on and interrupt an electrical connection disrupting the flow of current when switched off. Electrical switches are generally enclosed in cabinets that have an operating handle located outside the cabinets. The operating handle is used to operate the electrical switch. For example, the operating handle is rotated to an off position to interrupt a connection and is rotated to an on position to form an electrical connection. There may be a need for a mechanism that conditionally allows operation of the electrical switches.
One aspect of the present disclosure relates to an interlocking mechanism for a switching device. The interlocking mechanism can include an interlocking arm that has a first end and a second end. The interlocking arm can be movable between a first position and a second position. When positioned in the first position, the first end of the interlocking arm forms a releasable contact with a switch operating mechanism of a switching device to block operation of the switching device. When positioned in the second position, the first end of the interlocking arm withdraws from the releasable contact with the switch operating mechanism of the switching device to allow operation of the switching device. The interlocking mechanism further includes an actuator connected to the interlocking arm. The actuator, in response to receiving an actuator signal, moves the interlocking arm between the first position and the second position.
Another aspect of the present disclosure relates to a switching device that includes a cabinet and a switch control handle mounted outside the cabinet. The switch control handle can be pivotally movable about a handle axis between an off position and an on position. The switching device can further include a circuit unit mounted inside the cabinet and an actuator shaft connected to the circuit unit. The actuator shaft shifts the circuit unit to an open configuration when the switch control handle moves to the off position and shifts the circuit unit to a closed configuration when the switch control handle moves to the on position. The switching device can further include a crank member that can be pivoted at the handle axis and connected to the switch control handle. The switching device further includes an interlocking arm having a first end and a second end. The interlocking arm is movable between a first position and a second position. When positioned in the first position, the first end of the interlocking arm forms a releasable contact with the crank member to block pivotal movement of the switch control handle at the handle axis. When positioned in the second position, the first end of the interlocking arm withdraws from the releasable contact with the crank member to allow operation of the switch control handle. The switching device further includes an actuator connected to the interlocking arm. The actuator, in response to receiving an actuator signal, moves the interlocking arm between the first position and the second position.
Yet another aspect of the present disclosure relates to a method of operating a switching device. The method includes steps of: determining that a pre-determined condition for operating a switching device is met; generating, in response to determining that the pre-determined condition for the switching device is met, an actuator signal; and sending the actuator signal to an actuator connected to an interlocking arm of an interlocking device, the actuator, in response to receiving the actuator signal, moves the interlocking arm from a first position to a second position, wherein the interlocking arm includes a first end and a second end, wherein when positioned in the first position, the first end of the interlocking arm forms a releasable contact with the switch operating mechanism of the switching device to block operation of the switching device, and when positioned in the second position, the second end of the interlocking arm withdraws from the releasable contact with the switch operating mechanism of the switching device to allow operation of the switching device.
The accompanying drawings which are incorporated in and constitute a part of the description, illustrate several aspects of the disclosure. A brief description of the drawings is as follows:
Reference will now be made in detail to exemplary aspects of the present disclosure that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like structure.
A switching device (for example, electrical switch or a disconnect device) is typically used for controlling a flow of current by forming or interrupting an electrical connection. A switching device is generally housed in a cabinet or a box. The cabinet has an operating handle (also referred to as an operating lever or a switch handle) located outside the cabinet to operate the switching device. The operating handle is rotated along a pivot axis to an off position to interrupt an electrical connection and is rotated to an on position to an electrical connection. Some applications may require one or more pre-determined criteria to be met before the electrical connection is interrupted or formed.
This disclosure provides an interlocking mechanism for selective operation of a switching device. For example, and as discussed in greater detail in the following sections of the disclosure, the interlocking mechanism disclosed herein allows the operation of the switching device when one or more pre-determined criteria for forming or interrupting the electrical connection is met.
In examples, interlocking arm 102 is moved or rotated between the first position and the second position through an actuator 108. Actuator 108 is connected to second end 106 of interlocking arm 102. In some examples, actuator 108 includes an actuator plunger 110. In such examples, second end 106 of interlocking arm 102 is connected to actuator 108 through actuator plunger 110.
In some examples, actuator 108 can include a solenoid. The solenoid of actuator 108 can include a coil of a metal wire. When actuator 108 is energized, that is, when electrical current flows through the coil, a magnetic field is formed around the coil which draws actuator plunger 110 inwards that causes interlocking arm 102 to move or rotate from the first position to the second position. When actuator 108 is de-energized, that is, when the electrical current flowing through the coil is stopped or interrupted, the magnetic field around the coil dissipates and actuator plunger 110 is released causing interlocking arm 102 to move to the first position from the second position.
In some examples, a spring 112 is coiled around actuator plunger 110. Spring 112 is provided to assist in movement of interlocking arm 102. For example, spring 112 stores energy when actuator 108 draws actuator plunger 110 in and releases the stored energy when actuator 108 is de-energized. In some examples, the electrical current is provided to actuator 108 through input terminals 114. In some examples, the electrical current for actuator 108 is provided from the electrical switch. In other examples, the electrical current for actuator 108 is provided from an external source.
Actuator 108 is housed within an actuator housing 116. Actuator housing 116 is fixed or attached to an interlocking base 134. In some examples, first end 104 of interlocking arm 102 includes an interlocking head 118. A shape and size of interlocking head 118 is designed to form the releasable contact with switch operating mechanism 200 of switching device 220.
Interlocking mechanism 100 further includes a status mechanism 120. Status mechanism 120 can provide an indication of a current position of interlocking arm 102. In some examples, status mechanism 120 provides an indication when interlocking arm 102 is disengaged from or retracted from the releasable contact with switch operating mechanism 200 rendering switching device 220 operable. The indication can be provided in form of an indication light although alternatives are possible. For example, the indication light turns green when interlocking arm 102 is disengaged or retracted from the releasable contact rendering switching device 220 operable and turns red when interlocking arm 102 is engaged with or positioned on the releasable contact rendering switching device 220 inoperable. In some examples, the indication is provided in form of sound or a signal. In other examples, the indication is provided in form of a text message or a voice message.
Status mechanism 120 includes a status arm 122. A first end 124 of status arm 122 is connected to status mechanism 120 and a second end 126 of status arm 122 is located in a status notch 128 of interlocking arm 102. Status notch 128 includes a first side 130 and a second side 132 opposite first side 130. In some examples, status arm 122 is in contact with first side 130 of status notch 128 when interlocking arm 102 is in the second position and is in contact with second side 132 of status notch 124 when interlocking arm 102 is in the first position. Thus, status mechanism 120 provides the current position of interlocking arm 102 based on the current position of status arm 122. In some other examples, status mechanism 120 can detect the current position of interlocking arm 102 by sensing an amount of current being consumed by or flowing through actuator 108. For example, status mechanism 120 can detect that interlocking arm 102 is in the first position when the amount of current being consumed by or flowing through actuator 108 is approximately equal to zero and is in the second position when the amount of current being consumed by or flowing through actuator 108 is greater than zero.
In certain examples, actuator 108 is energized in response to receiving an actuator signal. The actuator signal is received over a wired network or a wireless network. In some examples, the actuator signal is received from a programmable circuit 136. Programmable circuit 136 determines that a pre-determined condition for operating switching device 220 is met, generates, in response to determining that the pre-determined condition for operating switching device is 220 met, the actuator signal, and sends the actuator signal to actuator 108. In response to receiving the actuator signal, actuator 108 is energized thereby allowing operation of switching device 220.
In examples, the pre-determined condition may include checking that one or more loads are switched off. In another example, the pre-determined condition may include determining that a device or equipment that draws more than a predetermined amount of current is switched off. In yet another example, the pre-determined condition may include determining that exposed wires or exposed contacts are covered to sealed.
In some examples, actuator 108 is energized for a predetermined time period. In other examples, actuator 108 is energized until switching device 220 is operated, that is, switched on or switched off. Programmable circuit 136 can be remote from actuator 108 or can be co-located with actuator 108. Programmable circuit 136 can be programmed to check one or more pre-determined conditions for operating the switch. In some examples, the one or more conditions can be dynamically changed.
In some examples, the actuator signal is received from a facility manager of a facility where switching device 220 to be operated is located. For example, the facility manager sends the actuator signal to actuator 108 over a wired network or a wireless network. In other examples, the actuator signal is received from a work site manager performing maintenance at the facility.
In certain examples, interlocking arm 102 is rotatable or movable around an arm axis 140. Arm axis 140 is also referred to as an arm pivot or simply as pivot. An arm axis fastener 142 is used to control ease of rotation at arm axis 140. For example, arm axis fastener 142 can be tightened and loosened to control the ease of rotation of interlocking arm 102. An arm base fastener 144 is used for fastening interlocking arm 102 to interlocking base 118. In examples, arm base fastener 144 is also used for controlling a degree of rotation or movement of interlocking arm 102. For example, arm base fastener 144 is tightened or loosened to decrease or increase the degree of rotation or movement of interlocking arm 102.
A plurality of actuator fasteners 146 are used for fastening actuator housing 116 to interlocking base 118. A plurality of interlocking fasteners 148 are used for fastening interlocking base 118 or interlocking mechanism 100 to the cabinet of the electrical switch. Plurality of actuator fasteners 146 and plurality of interlocking fasteners 148 may include nuts, bolts, screws, studs, etc.
In examples, a length and a shape of interlocking arm 102 is configurable.
In examples, the length and the shape of interlocking arm 102, therefore, can depend upon an available space inside a cabinet, for example, enclosure 300 shown in
Switch operating mechanism 200 further includes a crank member 206. Crank member 206 is also pivoted at handle pivot axis 204 and is moveably connected to switch control handle 202. For example, crank member 206 rotates or moves when switch control handle 202 is rotated or moved. In some examples, crank member 206 rotates in a same direction as switch control handle 202.
Crank member 206 includes a contact slot 208. In examples, contact slot 208 is a depression or an opening in a periphery of crank member 206. A shape and size of contact slot 208 is designed to receive first end 104 (or interlocking head 118) of interlocking arm 102. For example, the shape and size of releasable contact slot 208 is reciprocal to the shape and size of interlocking head 112 of interlocking arm 102. In some examples, crank member 206 further includes a blocking member 210 adjacent to contact slot 208. Blocking member 210 impedes rotation of crank member 206 when first end 104 of interlocking arm 102 is positioned in contact slot 208.
In examples, interlocking arm 102 of interlocking mechanism 100 forms a releasable contact with switch operating mechanism 200.
Switch operating mechanism 200 further includes a plurality of door prongs 212. Plurality of door prongs 212 form a door safety mechanism that does not allow door 306 of cabinet 300 that includes switching device 220 to open when switch control handle 202 is in the second position (that is, the power on configuration). In some examples, plurality of door prongs 212 are configured to not allow rotation or movement of switch control handle 202 to the operating second position (that is, the power on configuration) when door 306 of cabinet 300 is in the open position. In some other examples, plurality of door prongs 212 are configured to not allow opening of door 306 of cabinet 300 when switch control handle 202 is at the operating second position.
As shown in
Returning to
In some examples, each of plurality of switching units 224 include an assembly of electrical contacts that are switchable or shiftable between an open configuration (or an open condition) and a closed configuration (or closed condition). The assembly of electrical contacts are connected to an actuator shaft 222 that shifts the electrical contacts between their open and closed configurations. For example, actuator shaft 222 is connected to crank member 206 at handle pivot axis 204 and is moveably connected to switch control handle 202. For example, actuator shaft 222 rotates or moves when switch control handle 202 is rotated or moved between the first position and the second position. In some examples, actuator shaft 222 rotates in a same direction as switch control handle 202. Hence, when switch control handle 202 is rotated to the off position (that is, the first position), actuator shaft 222 shifts the electrical contacts to the open configuration, and when switch control handle 202 is rotated to the on position (that is the second position), actuator shaft 222 shifts the electrical contacts to the closed configuration. In some examples, at any given time, each of plurality of switching units 224 have a same configuration, either open or closed. In the open configuration, no current flows through the plurality of switching unites while in the closed configuration electric current flows through the plurality of switching unites.
Continuing with
In some examples, override actuator 402 is located outside of cabinet 300 and can be rotated to activate override mechanism 400. In some other examples, override actuator 402 is located inside of cabinet 300 and is accessible through a hole in cabinet 300. Override actuator 402 is rotated to adjust position of override arm 404 against bias of override spring 406. For example, when override actuator 402 is rotated, override arm 404 rotates in a same direction of override actuator 402 thereby moving interlocking arm 102 of interlocking mechanism 100 from the first position to the second position. Hence, when override actuator 402 is rotated, interlocking arm 102 retracts from the releasable contact with switch operating mechanism 200 thus defeating interlocking mechanism 100 and allowing operation of switching device 220.
At block 520 of method 500, an actuator signal is generated in response to determining that the pre-determined condition for operating switching device 220 is met. For example, programmable circuit 136 generates an actuator signal in response to determining that a pre-determined condition for operating switching device 220 is met.
At block 530 of method 500, the actuator signal is sent to actuator 108 connected to interlocking arm 102 of an interlocking mechanism 100. For example, programmable circuit 136 sends the actuator signal to actuator 108. Actuator 108, in response to receiving the actuator signal, moves interlocking arm 102 from a first position to a second position. Interlocking arm 102 includes first end 104 and second end 106. When positioned in the first position, first end 104 of interlocking arm 102 forms a releasable contact with switch operating mechanism 200 of switching device 220 blocking operation of switching device 220. When positioned in the second position, first end 104 of interlocking arm 102 withdraws from the releasable contact with switch operating mechanism 200 of switching device 220 allowing operation of switching device 220.
Various modifications and alternations of this disclosure will become apparent to those skilled in the art without departing from the scope and spirit of this disclosure, and it should be understood that the inventive scope of this disclosure is not to be unduly limited to the illustrative embodiments set forth therein.
This application claims the benefit of U.S. Provisional Patent Application No. 63/273,615, filed Oct. 29, 2021. The disclosure of the priority application in its entirety is hereby incorporated by reference into the presence application.
Number | Date | Country | |
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63273615 | Oct 2021 | US |