Meter assembly including a cover having integral bayonets and guard ears

Claim 1

An enclosure for an electroresponsive device comprising a unitary nonmetallic cover unit, said cover unit including a cupshaped section having a wall portion symmetric about an axis, an end portion closing one end of the wall portion, a plurality of integral, circumferentially spaced lugs projecting radially outwardly from said wall portion adjacent the open end of the cup-shaped section, an integral, separate guard ear projecting outwardly from said wall portion intermediate each adjacent pair of said lugs, said lugs and guard ears being arranged in pairs, with each pair comprising a guard ear and a lug extending away from the associated guard ear in a first direction angularly about the axis, said pairs being spaced from each other, a base unit, said base unit having an end part substantially closing the open end of the cup-shaped section, with said end part including a rim and a plurality of clamps carried by the rim, each of said clamps receiving a separate one of the lugs of the cover unit between the clamp and the rim, said clamps and lugs having mating surfaces which overlap in locking relationship which is releasable in response to relative rotation therebetween in a predetermined direction, each of said clamps being proportioned for movement through the space between adjacent ones of said pairs to permit removal of said cover unit from said base unit, a watthour meter located within the enclosure formed by said cover and base units, a plurality of contact blades projecting exteriorly from the base unit to establish connections between the meter and an external circuit, a socket having a plurality of contact jaws releasably engaging the contact blades, said socket having a flanged opening closed by said base unit, and a sealing ring having a web and flanges defining a substantially U-shaped cross section, said sealing ring being disposed to maintain the assembled relation of the cover, base and socket, and prevent removal of the cover unit by working one lug at a time free from said sealing ring, by snugly enclosing the clamps, lugs, rim and socket flange between its flanges at predetermined circumferentially spaced locations, and by snugly enclosing the guard ears, rim and socket flange between its flanges in the spaces between the circumferentially spaced cooperative clamps and lugs.