Patent ID: 8864530

Claim:
A jack having a switch mechanism of a single-butt contact type comprising: a body defining a plug insertion hole; and a switch mechanism situated on one side of said body, said switch mechanism comprising: a stationary contact piece mounted to said body; a movable contact piece mounted to said body and having a plate spring serving as a cantilevered beam with a basal end portion and a tip end portion, said contact pieces being located opposite to each other outside said plug insertion hole in a manner that, when a plug is inserted, said contact pieces are not contacted with the plug; and an insulator comprising a basal portion, a tip end portion, and a middle portion, wherein a pressed portion of said insulator, which extends from said middle portion toward the tip end portion, is spaced from the movable contact piece and extends into the plug insertion hole so as to form a gap between the pressed portion and the movable contact piece, and wherein a spring portion of insulator, which extends from the basal portion toward the middle portion, is in contact with the movable contact piece, whereby, when the plug is inserted into the plug insertion hole, said spring portion of the insulator is pressed by the plug and displaced such that a displacement load is applied by said insulator to a middle portion in a length direction of said movable contact piece to flex said movable contact piece while setting said basal end portion of said movable contact piece as a fulcrum, and wherein: said tip end portion of said movable contact piece contacts said stationary contact piece, and thereafter said middle portion in the length direction of said movable contact piece is flexed while setting said tip end portion as a fulcrum, to apply a contact pressure on a contact.