Electrical adapters

An electrical adapter comprising an adapter body, a face panel covered on a front side of said adapter body, and an electrical circuit mounted inside said adapter body, wherein said face panel comprises a plurality of grounding prong insertion holes longitudinally aligned a middle portion of said face panel adapted to receive grounding prongs of different electrical plugs, two first power contact blade insertion holes and two second power contact blade insertion holes bilaterally disposed at different elevations and adapted to receive power contact blades of different electrical plugs, a backward guide rod, a first sliding cover coupled to said backward guide rod by a slip joint and adapted to close said first power contact blade insertion holes, said first sliding cover having an upwardly backwardly extended sloping guide face at a front side corresponding to one grounding prong insertion hole, said first sliding cover being downwardly moved away from said first power contact insertion holes when a grounding prong of an electrical plug is inserted into one grounding prong insertion hole and forced against the sloping guide face of said first sliding cover, first spring means adapted to impart an upward pressure to said first sliding cover, causing said first sliding cover to close said first power contact blade insertion holes, a second sliding cover adapted to close said second power contact blade insertion holes, said second sliding cover having a top block at a front side thereof said top block having a sloping guide face corresponding to one grounding prong insertion hole, said top block being forced to move said second sliding cover upwardly away from said second power contact blade insertion holes when a grounding prong of an electrical plug is inserted into one grounding prong insertion hole and forced against the sloping guide face of said top block, second spring means adapted to impart a downward pressure to said second sliding cover, causing said second sliding cover to close said second power contact blade insertion holes;

• said adapter body comprises a plug unit at a first lateral side thereof and a socket unit at a second lateral side thereof, the size of said plug unit fitting that of said socket unit so that a plurality of electrical adapters can be connected in series by plugging the plug unit of one electrical adapter into the socket unit of another, a longitudinal coupling groove at its second lateral side and a pair of longitudinal coupling plates at its first lateral side, a tie hole pierced through one corner thereof and intersected with said longitudinal coupling groove, said longitudinal coupling plates having a respective through hole, said longitudinal coupling plates and said longitudinal coupling groove being so arranged that the longitudinal coupling plates of one electrical adapter are fitted into the longitudinal coupling groove of another when a plurality of electrical adapters are connected in series, permitting the through holes of the longitudinal coupling plates of one electrical adapter to be fastened to the tie hole of another electrical adapter by a fastening element.