1. Field
The disclosed concept relates generally to electrical switching apparatus and, more particularly, to electrical switching apparatus, such as circuit breakers. The disclosed concept also relates to close latch interlock assemblies for circuit breakers.
2. Background Information
Electrical switching apparatus, such as circuit breakers, provide protection for electrical systems from electrical fault conditions such as, for example, current overloads, short circuits, abnormal voltage and other fault conditions. Typically, circuit breakers include an operating mechanism, which opens electrical contact assemblies to interrupt the flow of current through the conductors of an electrical system in response to such fault conditions as detected, for example, by a trip unit. The electrical contact assemblies include stationary electrical contacts and corresponding movable electrical contacts that are separable from the stationary electrical contacts.
Among other components, the operating mechanisms of some stored energy circuit breakers, for example, typically include a pole shaft, a trip actuator assembly, a closing assembly and an opening assembly. The trip actuator assembly responds to the trip unit and actuates the operating mechanism. The closing assembly and the opening assembly may have some common elements, which are structured to move the movable electrical contacts between a first, open position, wherein the movable and stationary electrical contacts are separated, and a second, closed position, wherein the movable and stationary electrical contacts are electrically connected. Specifically, the movable electrical contacts are coupled to the pole shaft. Elements of both the closing assembly and the opening assembly, which are also pivotably coupled to the pole shaft, pivot the pole shaft in order to effectuate the closing and opening of the electrical contacts. The closing assembly includes a chargeable stored energy mechanism such as, for example and without limitation, a closing spring, and a close button to actuate (e.g., discharge) the closing spring to facilitate the closing process.
As shown, for example, in
The interlock assembly 4 includes an elongated linking element, commonly referred to as the close block link 10, which cooperates with the close D-shaft 12 of the circuit breaker 2. More specifically, a first end 14 of the close block link 10 is coupled to a lever 18 of the close D-shaft 12, and a second end 16 extends outwardly away from the close D-shaft 12, as shown. A portion of the second end 16 cooperates with a spring release member 20, as partially shown in phantom line drawing in
There is, therefore, room for improvement in electrical switching apparatus, such as circuit breakers, and in close latch interlock assemblies therefor.
These needs and others are met by embodiments of the disclosed concept, which are directed to a close latch interlock assembly for an electrical switching apparatus, such as a circuit breaker. Among other benefits, the mass of the close latch interlock assembly is not coupled to the close D-shaft of the circuit breaker, thereby minimizing the likelihood of unintended movement of the close D-shaft and possible discharge of the circuit breaker caused, for example and without limitation, by shock and/or vibration.
As one aspect of the disclosed concept, a close latch interlock assembly is provided for an electrical switching apparatus. The electrical switching apparatus includes a housing, separable contacts enclosed by the housing, and an operating mechanism for opening and closing the separable contacts. The operating mechanism includes a stored energy mechanism. The close latch interlock assembly comprises: a close D-shaft structured to be pivotably coupled to the housing, the close D-shaft being structured to pivot between a latched position corresponding to the stored energy mechanism being chargeable, and an unlatched position corresponding to the stored energy mechanism being discharged; an actuator structured to be movably coupled to the housing, the actuator being movable between an unactuated position corresponding to the close D-shaft being disposed in the latched position, and an actuated position corresponding to the close D-shaft being movable toward the unlatched position; a release member structured to cooperate with the actuator; and a transfer link including a first end pivotably coupled to the release member, and a second end extending outwardly from the release member toward the close D-shaft. When the actuator is moved toward the actuated position, the actuator moves the release member, thereby moving the second end of the transfer link and pivoting the close D-shaft toward the unlatched position.
The actuator may be a close button. The close button may comprise a pivot pin, a generally planar portion including a first end and a second end disposed opposite and distal from the first end of the generally planar portion, and a button portion extending outwardly from the generally planar portion between the first end of the generally planar portion and the second end of the generally planar portion. The first end of the generally planar portion may be pivotably coupled to the pivot pin, and the second end of the generally planar portion may be pivotable into and out of engagement with the release member. The close button may further comprise an indicator, wherein the generally planar portion includes an opening extending through the generally planar portion proximate to the second end of the generally planar portion, wherein the indicator is structured to provide a visual indication of whether or not the electrical switching apparatus is ready to close, and wherein the indicator is disposed within the opening.
The close D-shaft may include a recess, wherein the recess is structured to receive a portion of the second end of the transfer link. The second end of the transfer link may include a hook portion, wherein the hook portion extends toward the close D-shaft, and wherein the hook portion is movable into and out of engagement with the close D-shaft at or about the recess. When the actuator is disposed in the unactuated position, the hook portion may not engage the close D-shaft, when the actuator is moved toward the actuated position, the hook portion may move into the recess and engages and pivot the close D-shaft toward the unlatched position, and after the close D-shaft has been moved to the unlatched position, the hook portion may move out of the recess and disengages the close D-shaft.
The release member may comprise an exterior, a first side, and a second side disposed opposite the first side. The first end of the transfer link may be pivotably coupled to the second side of the release member.
As another aspect of the disclosed concept, an electrical switching apparatus comprises: a housing; separable contacts enclosed by the housing; an operating mechanism for opening and closing the separable contacts, the operating mechanism comprising a stored energy mechanism and a close D-shaft, the close D-shaft pivoting between a latched position corresponding to the stored energy mechanism being chargeable, and an unlatched position corresponding to the stored energy mechanism being discharged; and a close latch interlock assembly comprising: an actuator movably coupled to the housing of the electrical switching apparatus, the actuator being movable between an unactuated position corresponding to the close D-shaft being disposed in the latched position, and an actuated position corresponding to the close D-shaft being movable toward the unlatched position, a release member cooperating with the actuator, and a transfer link including a first end pivotably coupled to the release member, and a second end extending outwardly from the release member toward the close D-shaft. When the actuator is moved toward the actuated position, the actuator moves the release member, thereby moving the second end of the transfer link and pivoting the close D-shaft toward the unlatched position.
The electrical switching apparatus may be a circuit breaker, the stored energy mechanism may be a closing spring, and the actuator may be a close button. When the circuit breaker is ready to close, the close button may be actuatable to move the latch interlock assembly to unlatch the close D-shaft, thereby discharging the closing spring to close the separable contacts. When the circuit breaker is not ready to close, the close latch interlock assembly may prevent the close D-shaft from moving to the unlatched position.
A full understanding of the disclosed concept can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:
Directional phrases used herein, such as, for example, left, right, up, down, clockwise, counterclockwise, top, bottom and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein.
As employed herein, the statement that two or more parts are “coupled” together shall mean that the parts are joined together either directly or joined through one or more intermediate parts.
As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality).
Continuing to refer to
A release member such as, for example and without limitation, the release paddle 206 shown and described herein, cooperates with the close button 204. Specifically, the close latch interlock assembly 200 further includes a transfer link 208 having a first end 210, which is pivotably coupled to the release paddle 206. The second end 212 of the transfer link 202 extends outwardly from the release paddle 206 toward the close D-shaft 202, as shown. Accordingly, it will be appreciated that, unlike prior art interlock assemblies (see, for example, interlock assembly 4 of
In addition to removing the mass of the transfer link 208 from the close D-shaft 202, among other benefits, the disclosed close latch interlock assembly 200 also reduces tolerance and assembly errors associated with prior art interlock designs (see, for example, interlock assembly 4 of
In operation, when the close button 204 is moved (e.g., depressed downwardly in the direction of arrow 300 in
The example close button 204 further includes a projection 224 extending outwardly from the second end 220 of the generally planar portion 216, toward the release paddle 206. Thus, when the close button 204 is moved from the unactuated position toward the actuated position, as shown in phantom line drawing in
The close button 204 of the close latch interlock assembly 200 preferably further includes an indicator such as, for example and without limitation, the pivotable ready-to-close flag 232, shown in
As previously discussed, the transfer link 208 of the example close latch interlock assembly 200 is not mechanically coupled to the close D-shaft 202. Rather, the transfer link 208 cooperates with the close D-shaft 202 by way of interaction of the second end 212 of the transfer link 208 with a recess 236 of the close D-shaft 202. Specifically, the second end 212 of the transfer link 202 preferably includes a hook portion 238, which extends generally toward (e.g., without limitation, curves toward) the close D-shaft 202, as shown. The hook portion 238 is movable into and out of engagement with the close D-shaft 202 at or about the recess 236, as shown in
As shown in solid line drawing in
As previously discussed, another advantage of the disclosed close latch interlock assembly 200 relates to the fact that the first end 210 of the transfer link 208 is coupled to the exterior 240 of the release paddle 206. Specifically, as best shown in
Accordingly, the disclosed close latch interlock assembly 200 provides an improved mechanism for controlling the closing operation of the circuit breaker 102 (
While specific embodiments of the disclosed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.