Abstract: A test socket has movable contact elements blanked from sheet metal to provide each element with a mounting leg part, a contact part at an edge of the blanked sheet metal, and a resilient curved part between the leg and contact parts permitting the contact part to be moved into and out of engagement with terminals of an IC unit to be tested in the socket and has a plurality of projections formed in side-by-side relation to each other in the edge of the sheet metal at the contact part for improving the making and breaking of electrical connection to the IC unit terminal.

Abstract: A socket is described having not only contactors secured to the socket body and electrically connected in an elastically pressed condition of these contactors to a given electrical part mounted but a slide cover slidably fitted to the socket body wherein tapered surfaces are formed in sliding contact areas of such contactors to the slide cover in such a manner that as the slide cover slides a force may be generated to elastically deform and release these contactors from electrical connection to such electrical part.

Abstract: A Plug-in socket assembly for use with a semiconductor integrated circuit package has a plurality of contact elements mounted on a support member. The contact elements are each formed with a spring portion, an elongated arm portion merging out of the spring portion to an inner lug portion engageable with a contact pin of the integrated circuit package and an outer lug portion in engagement with a housing member movable downwardly toward and upwardly away from the support member. The housing member is formed with an open space to receive the integrated circuit package therein and a carrier unit adapted to support the integrated circuit package is mounted on the support member and is movable relative to both the support and the housing members.