1. Field of the Invention
The invention relates generally to electrical switching apparatus and, more particularly, to electrical switching apparatus, such as circuit breakers. The invention also relates to push-to-trip assemblies for electrical switching apparatus.
2. Background Information
Electrical switching apparatus, such as circuit interrupters, generally include at least one pair of separable contacts which are operated either manually, by way of a handle and/or another suitable manually operated trip actuator accessible on the exterior of the circuit interrupter housing, or automatically by way of a trip unit in response to a trip condition (e.g., without limitation, an overcurrent condition; a relatively high level short circuit or fault condition; a ground fault or arc fault condition).
Among other disadvantages, it is difficult to hold the various components (e.g., without limitation, push-to-trip button 5; spring 11; trip bar 17) of the push-to-trip assembly 3 and/or circuit breaker 1 together during assembly of the circuit breaker 1. Specifically, the push-to-trip button 5, which is spring-biased, is dependent on an external stop such as, for example, the housing 15 (e.g., cover) of the circuit breaker 1 to hold it in place. Further complicating the assembly process is the fact that the spring 11 also, directly or indirectly, biases the trip bar 17 of the circuit breaker 1. Specifically, absent a suitable stopping mechanism for resisting undesired rotation of the trip bar 17, it is difficult to achieve the desired orientation of the trip bar 17 during assembly of the circuit breaker 1. For example, assembly of the circuit breaker 1 is reliant upon the trip bar 17 abutting bimetal 25 of circuit breaker heater assembly 27. It would be preferable to avoid such abutment. Moreover, in circumstances where the push-to-trip assembly 3 and/or the trip bar 17 is/are assembled and installed in the circuit breaker 1 before the installation of the heater assembly 27, the bimetal 25 is not available for use as a stop to resist over rotation of the trip bar 17.
There is, therefore, room for improvement in electrical switching apparatus and in push-to-trip assemblies therefor.
These needs and others are met by embodiments of the invention, which are directed to a push-to-trip assembly for an electrical switching apparatus, wherein the push-to-trip assembly includes a number of structures to facilitate assembly of the electrical switching apparatus.
As one aspect of the invention, a push-to-trip assembly is provided for an electrical switching apparatus. The electrical switching apparatus includes a housing, separable contacts and a trip bar cooperating with an operating mechanism to trip open the separable contacts. The housing includes a base, a cover coupled to the base, and an exterior. The push-to-trip assembly comprises: a push-to-trip actuator structured to be movably coupled to the base of the housing, the push-to-trip actuator comprising a first end and a second end disposed opposite and distal from the first end, the push-to-trip actuator being further structured to move among a first position corresponding to the separable contacts being closeable, and a second position corresponding to the second end of the push-to-trip actuator cooperating with the trip bar to cause the operating mechanism to trip open the separable contacts, the first end of the push-to-trip actuator being structured to be accessible from the exterior of the housing to actuate the push-to-trip actuator from the first position to the second position; a biasing element structured to bias the push-to-trip actuator away from the base of the housing toward the first position; at least one cover stop disposed on the push-to-trip actuator, the at least one cover stop being structured to engage a corresponding portion of the cover of the housing to stop movement of the push-to-trip actuator away from the base of the housing; and an overtravel restraint disposed proximate the second end of the push-to-trip actuator, the overtravel restraint being structured to restrain movement of the trip bar.
The cover of the housing may be a primary cover disposed on the base of the housing and a secondary cover coupled to the primary cover, and the at least one cover stop may be a primary cover stop and a secondary cover interface. The primary cover stop may be disposed on the push-to-trip actuator between the first end of the push-to-trip actuator and the second end of the push-to-trip actuator. When the primary cover is disposed on the base and the secondary cover is not coupled to the primary cover, the primary cover stop may be structured to engage the primary cover. The secondary cover interface may be disposed at or about the first end of the push-to-trip actuator. When the secondary cover is coupled to the primary cover and the push-to-trip actuator is disposed in the first position, the secondary cover interface may be structured to engage the secondary cover of the housing.
The trip bar may comprise at least one protrusion extending laterally outwardly from the trip bar. The push-to-trip actuator may further comprise an engagement segment extending outwardly from the push-to-trip actuator at or about the second end thereof. When the push-to-trip actuator is actuated from the first position toward the second position, the engagement segment may be structured to engage a corresponding one of the at least one protrusion of the trip bar, thereby moving the trip bar to cause the operating mechanism to trip open the separable contacts of the electrical switching apparatus. The overtravel restraint of the push-to-trip actuator may comprise a restraint segment disposed opposite and spaced apart from the engagement segment of the push-to-trip actuator. The overtravel restraint may be structured to receive a corresponding one of the at least one protrusion of the trip bar between the engagement segment of the push-to-trip actuator and the restraint segment of the overtravel restraint in order to restrain movement of the trip bar. The at least one protrusion of the trip bar may include a first protrusion extending laterally outwardly from the trip bar and a second protrusion extending laterally outwardly from the trip bar generally opposite the first protrusion, and the push-to-trip actuator may further comprise an interlock extending outwardly from the push-to-trip actuator at or about the second end thereof. The overtravel restraint may be structured to receive the first protrusion of the trip bar between the engagement segment of the push-to-trip actuator and the restraint segment of the overtravel restraint, and the interlock of the push-to-trip actuator may be structured to cooperate with the second protrusion of the trip bar.
As another aspect of the invention, a push-to-trip assembly is provided for an electrical switching apparatus. The electrical switching apparatus includes a housing, separable contacts and an operating mechanism structured to open and close the separable contacts. The housing includes a base, a primary cover disposed on the base, a secondary cover coupled to the primary cover and an exterior. The push-to-trip assembly comprises: a push-to-trip actuator structured to be movably coupled to the base of the housing, the push-to-trip actuator comprising a first end and a second end disposed opposite and distal from the first end, the push-to-trip actuator being further structured to move among a first position corresponding to the separable contacts being closeable, and a second position corresponding to the second end of the push-to-trip actuator cooperating with the operating mechanism to open the separable contacts, the first end of the push-to-trip actuator being structured to be accessible from the exterior of the housing to actuate the push-to-trip actuator from the first position to the second position; a biasing element structured to bias the push-to-trip actuator away from the base of the housing toward the first position; a primary cover stop disposed on the push-to-trip actuator between the first end of the push-to-trip actuator and the second end of the push-to-trip actuator, the primary cover stop being structured to stop movement of the push-to-trip actuator away from the base of the housing when the primary cover is disposed on the base of the housing and the secondary cover of the housing is not coupled to the primary cover; and a secondary cover interface disposed at or about the first end of the push-to-trip actuator, the secondary cover interface being structured to engage the secondary cover of the housing when the secondary cover is coupled to the primary cover of the housing and the push-to-trip actuator is disposed in the first position.
As another aspect of the invention, an electrical switching apparatus comprises: a housing including a base, a primary cover disposed on the base, a secondary cover coupled to the primary cover, and an exterior; separable contacts enclosed by the housing; an operating mechanism structured to open and close the separable contacts; a trip bar cooperating with the operating mechanism to trip open the separable contacts; and a push-to-trip assembly comprising: a push-to-trip actuator movably coupled to the base of the housing, the push-to-trip actuator comprising a first end and a second end disposed opposite and distal from the first end, the push-to-trip actuator being movable among a first position corresponding to the separable contacts being closeable, and a second position corresponding to the second end of the push-to-trip actuator cooperating with the trip bar to cause the operating mechanism to trip open the separable contacts, the first end of the push-to-trip actuator being accessible from the exterior of the housing to actuate the push-to-trip actuator from the first position to the second position, a biasing element biasing the push-to-trip actuator away from the base of the housing toward the first position, a primary cover stop disposed on the push-to-trip actuator between the first end of the push-to-trip actuator and the second end of the push-to-trip actuator, the primary cover stop stopping movement of the push-to-trip actuator away from the base of the housing when the primary cover is disposed on the base of the housing and the secondary cover of the housing is not coupled to the primary cover, a secondary cover interface disposed at or about the first end of the push-to-trip actuator, the secondary cover interface engaging the secondary cover of the housing when the secondary cover is coupled to the primary cover of the housing and the push-to-trip actuator is disposed in the first position, and an overtravel restraint disposed proximate to the second end of the push-to-trip actuator, the overtravel restraint restraining movement of the trip bar.
A full understanding of the invention 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, downward, upward, 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 term “fastener” refers to any suitable connecting or tightening mechanism expressly including, but not limited to, rivets, screws, bolts and the combinations of bolts and nuts (e.g., without limitation, lock nuts), and bolts, washers and nuts, as well as connecting mechanisms that do not require a separate fastening element (e.g., without limitation, a rivet; a screw; a bolt and a nut; a combination of bolts, washers and nuts) such as, for example and without limitation, an arrangement of interlocking protrusions or projections (e.g., without limitation, tabs) and apertures (e.g., without limitation, openings; recesses; holes; slots).
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 biasing element such as, for example and without limitation, a spring 108 (
The example push-to-trip assembly 100 further includes an overtravel restraint 114 (
The aforementioned overtravel restraint 114 of the push-to-trip actuator 102 includes a restraint segment 118 (
As best shown in
The interlock 120 of the push-to-trip actuator 102 is generally opposite and spaced apart from the overtravel restraint 114, as shown in
As noted previously, the push-to-trip actuator 102 of the example push-to-trip assembly 100 includes a primary cover stop 110 (
Continuing to refer to
The secondary cover interface 112 is disposed at or about the first end 104 of the push-to-trip actuator 102 and, in the example shown and described herein, consists of a notch 130 and a contact surface 136, which is structured to engage the secondary cover 216 at an opening 224 thereof, as best shown in
Specifically, as shown in
Accordingly, the disclosed push-to-trip assembly 100 manual trip actuator (e.g., push-to-trip actuator 102), which cooperates with the circuit breaker operating mechanism (e.g., trip bar 208) and/or the circuit breaker cover (e.g., primary cover 214; secondary cover 216) in order to facilitate the assembly of the circuit breaker 200, and to control the movement of the push-to-trip actuator 102, as desired.
While specific embodiments of the invention 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 invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.
Number | Name | Date | Kind |
---|---|---|---|
3826951 | Mater et al. | Jul 1974 | A |
4000478 | Jencks et al. | Dec 1976 | A |
6111486 | Fischer et al. | Aug 2000 | A |
6229418 | Mueller et al. | May 2001 | B1 |
6232855 | Malingowski et al. | May 2001 | B1 |
6700082 | Gibson et al. | Mar 2004 | B1 |
Number | Date | Country | |
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20090301850 A1 | Dec 2009 | US |