Abstract: A unitized shelf and guide framework for supporting so-called printed circuit cards in spaced alignment. Open-work shelves are joined, for example by welding, in accurate alignment to corner posts to form a frame. Each shelf consists of longitudinal channel members extending in parallel array between end flanges, and may be formed by punch press of a single piece of metal. The channel members are covered by split sheathes, which may be molded of a plastic, and which carry transversely extending alignment bosses for guiding and positioning the circuit cards. A wired back plane of the usual kind is secured in predetermined alignment behind each shelf, and carries the usual receptors for the pin terminals that extend from the back edges of the cards.

Abstract: A container assembly for a telephone repeater or the like including a circular flat base of metal and a dome-like cover of plastic. The cover includes an outwardly extending, flared flange for engagement against a chamfered outer edge portion of the base. The flange is secured to the base by a V-groove ring, one wall of which defines, in conjunction with the chamfer of the base, an outwardly flared annular chamber for receiving the flared flange. An O-ring is seated in a groove in the chamfer of the base in pressure engagement against the flared flange of the cover.The arrangement maintains an air tight seal between the cover and the base over a wide range of temperatures despite a difference between the thermal expansion characteristics of the metallic base and the plastic cover.