Patent Application
20110147171
1. Field of the Invention
The field of the present invention relates to an enclosure for an electrical device generally, and more particularly to an interlockable enclosure cover for a switch, such as a circuit breaker, of which the following is a specification, reference being had to the drawings accompanying and forming a part of the same.
2. Description of the Related Art
In conventional electrical distribution and control systems, electrical switching devices such as circuit breakers for switching power ON and OFF are often enclosed in an housing having an openable cover. Such housings are typically of metallic or polymeric material and include a hinged door or removeable cover providing access to the interior of the housing. Non-limiting examples of conventional electrical device housings include switch enclosures, busway “busplugs”, motor control centers, panelboards, and switchgear.
In
When closed, the door 104 prevents direct operative access to the operating member 103 of the enclosed switch 101. Operating handle 102 mounted external to the enclosure 100 and movable in the directions indicated by arrow 119 is configured to drive a mechanism including, for example, a moveable yoke 105, which in turn drives the operating member 103 of switch 101 for toggling the switch 101 from a power ON position to a power OFF position. Labels (not shown) having text such as “ON” and “OFF”, are positioned on enclosure 100 to correspond to operating handle 102 positions that likewise correspond to, and thus indicate, the state of the enclosed switch 101.
Various electrical standards require, as a safety feature, an interlock or latch mechanism to prevent opening of the door or removal of the cover while the enclosed switch is in the ON or conducting state. Prior art interlock assemblies 141 are conventionally configured to cooperate with a mechanism 142 driven by the externally-mounted operating handle 102 to prevent the opening of the door 104 while the enclosed switch 101 is in the ON or conducting state.
While safety latch assemblies for enclosures are generally known in the art, they have certain disadvantages. They are generally complex and expensive, often with a relatively large number of parts, and some permit closing of the cover 104 with the enclosed switch 101 in the ON position. This latter disadvantage can result in the enclosed switch 101 being in an ON or conducting state while the external operating member 102 position incorrectly indicates that the enclosed switch 101 is in an OFF or non-conducting state, thus resulting in a potentially hazardous condition.
It is desirable to provide an improved device configured to allow direct external operability of a switch or circuit interrupter installed in a housing, with a simpler, low cost apparatus to prevent opening and/or closing of the enclosure cover when the enclosed switch is in the “ON” position.
In view of the foregoing considerations, it is desirable to provide a device to provide an enclosure having a safety latch assembly that is relatively simple in construction, using a minimum number of parts that prohibits closing of the enclosure cover with the enclosed switch in the ON position, and preferably prevents both closing and opening of the enclosure cover with the enclosed switch in the ON position.
In an embodiment, an enclosure for a switching device having an operating member operable between a first ON and a second OFF position is provided. The enclosure comprises a simple latch assembly that is configured to move in response to the operation of the enclosed switching device operating member to prevent opening of the enclosure when the enclosed switch 101 is in the first ON position.
In another embodiment, an openable cover for an enclosure configured to house a switching device configured with an operating member operable between a first ON and a second OFF position, is provided. The openable cover comprises a moveable member operable in response to movement of the switching device operating member and is configured to prevent opening of the cover member when the operating member is in the first ON position.
Other features and advantages of the disclosure will become apparent by reference to the following description taken in connection with the accompanying drawings.
Although specific features of the invention are shown in some drawings and not in others, this is for convenience only as one or more of the features of any drawing may be combined with any or all of the other features of one or more of the remaining drawings in accordance with one or more embodiments of the invention.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate a presently preferred embodiment of the invention, in which:
As used herein, an element or function recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural said elements or functions, unless such exclusion is explicitly recited. Furthermore, references to “one embodiment” of the claimed invention should not be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views.
In
The door 204 may be retained in a closed position by fasteners such as screws 206a, 206b and/or any number of releasable door-latching mechanisms having a latch member 208 arranged to protrude through a second aperture 212a in the door 204. Latch member 208 is provided with an aperture 212b configured to receive a locking member (not shown) such as the hasp of a lock (not shown) for locking the cover 204 closed. It is contemplated that in some embodiments, the door 204 may be hingeably attached to the enclosure 200, such as, for example, with hinges 233a, 233b cooperating with apertures 234a, 234b.
An interlock member 225 having a top surface 226a and a bottom surface 226b (
In an embodiment, interlock member 225 is provided with a third notch, opening, or aperture 223, positioned to allow the switch 101 operating member 103 to protrude therethrough when the cover 204 is closed. Interlock member 225 aperture 223 and cover 204 aperture 211 are configured to cooperate to allow the installed switch 101 operating handle 103 to protrude external to the housing 200 and to allow direct operation of the switch 101 operating handle 103. In order to allow operation of switch 101 when the cover 204 is closed, the interlock member 225 aperture 223 is configured such that movement of the switch operating member 103 causes movement of the interlock member 225.
It is contemplated that the movable connection of interlock member 225 to door 204 may be accomplished through a variety of ways. For example, in one embodiment, two fasteners or shouldered rivets 230, 231 connect interlock member 225 to the first interior surface 256 door 204. Two or more generally parallel slots 227, 228 are disposed in interlock member 225 and are configured to slidably capture respective shouldered rivets 230, 231. A first end of each of the rivets 230, 231 are fixedly attached to door 204 via peening or other known methods. A second end of the at least two rivets 230, 231 are disposed through respective slots 227, 228 in interlock member 225.
Referring again to
It is contemplated that the interlock formation 260 may embody a variety of forms to accommodate a latching function in cooperation with the corresponding latching portion 229 of interlock member 225. In one exemplary embodiment, and as shown in
Referring to
With respect to the above description, it should be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, form function and manner of operation, assembly and use, are deemed readily apparent and illustrated in the drawings and described in the specification are intended to be encompassed only by the scope of appended claims.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
