Receptacles – Outlet or junction box type – With closure
Reexamination Certificate
1998-06-26
2001-01-30
Moy, Joseph M. (Department: 3727)
Receptacles
Outlet or junction box type
With closure
C220S004020, C220S324000, C220S003200
Reexamination Certificate
active
06179144
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to electrical enclosures, and particularly to weatherproof electrical enclosures with side hinged covers.
BACKGROUND OF THE INVENTION
Electrical enclosures for exterior applications are required to prohibit the ingress of liquids in the form of dripping water of driven rain above the lowest point of the enclosed electrical devices. When the enclosure provides protection for electrical switches, circuit breakers or other circuit protection devices which produce gases during abnormal conditions (short circuit conditions), the enclosure cover must be sufficiently restrained to prohibit forced opening by the pressure of those gasses. Generally, enclosures providing these features have employed top hinged covers that rotate upward with overlapping drip flanges on the enclosure top and screw type fasteners, or screw attached covers with overlapping drip flanges on the enclosure top. A weatherproof electrical enclosure manufactured by Murray Electrical Products, a division of Siemens Energy & Automation, Inc., employs a side-hinged cover. The Murray cover operates in a manner similar to a top hinged enclosure in that the cover must be raised after closing such that the top edge of the cover will be positioned behind the overlapping drip flange on the enclosure top. A latch attached to the bottom of the enclosure engages a flange along the bottom of the cover to hold the cover in the raised position. Other weatherproof side-hinged covers are known, however, most require some type of gasketing or sealing to prevent the ingress of liquids. Sealing of the enclosure can cause deformation of the enclosure and/or opening of the cover due to pressure from gasses produced by the operating circuit protection devices inside the enclosure. U.S. patent application Ser. No. 08/942,343, filed on Oct. 1, 1997, assigned to the present assignee and incorporated herein by reference, teaches a side hinged weatherproof enclosure. The methods of preventing the ingress of liquid disclosed in the above patent application are most effective on small enclosures such as air-conditioner disconnect switches. The cover latching means disclosed therein is not intended to prevent the cover from being forced open by the pressure of expanding internal gasses. It would therefore be desirable to have a simple means of preventing the ingress of liquids into an electrical enclosure, which does not require a sealing means. It is further desirable to provide a cover latching means, other than screws, which will maintain the integrity of the cover while allowing gasses produced by circuit protection devices to escape without causing significant damage to the enclosure. It would be most desirable to incorporate these features in an enclosure with a side-hinged cover.
SUMMARY OF THE INVENTION
The present invention provides a weatherproof enclosure with side hinged cover and a screwless cover latching means which is not defeated by the pressure of expanding internal gases. The enclosure includes a rain channel located immediately adjacent a front edge of the box top. The rain channel is generally J-shaped in cross-section and extends across the front of the box and slightly beyond the two side walls of the box such that any liquid being received within the rain channel will be directed over the side walls. The rain channel cooperates with a downwardly extending flange along the front edge of the box top and an inwardly extending flange along the top of the side hinged cover to prevent the ingress of liquid at the top of the cover. Inwardly facing flanges along the sides of the hinged cover overlap the side walls of the box to prevent the ingress of liquid along each side of the cover. The cover latch is positioned approximately at the center of the cover side such that the corners of the cover can flex slightly to relieve the inside pressure caused by circuit protection devices operating in response to a short circuit. Since the cover latch and its latching slot are positioned above the lowest point of live electrical components inside the enclosure, the latch and latching slot must be weatherproof. Therefore, the cover latch is positioned outside the side wall of the box such that the corresponding opening in the cover is also outside the box side wall thus preventing the ingress of liquid through the latch opening. The configuration of the cover latch and the latch opening is such that pressure exerted on the inside surfaces of the enclosure causes a positive latching effect between the cover and the latch.
REFERENCES:
patent: 3912348 (1975-10-01), Seymour
patent: 3955709 (1976-05-01), Coley et al.
patent: 4102475 (1978-07-01), Kalvaitis
patent: 4484692 (1984-11-01), Palermo et al.
patent: 4502609 (1985-03-01), Christatos
patent: 4890318 (1989-12-01), Crane et al.
patent: 5148348 (1992-09-01), White
patent: 5499734 (1996-03-01), Tessmer
patent: 5669522 (1997-09-01), Million et al.
Abroy Hamid S.
Chambers William K.
Dodier Gary H.
Newsome Norman M.
Golden Larry I.
Moy Joseph M.
Shrout Larry T.
Square D Company
Stacey David R.
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