Double-headed spring contact probe

A double-headed spring contact probe (20) for loaded board testing includes a barrel (22) having a hollow interior (25) and opposed plungers (30,50) which slide axially in the barrel. The plungers have outer portions (36,58) which extend through the opposite open ends (23,24) of the barrel, each terminating in a contact tip (38,60) outside the barrel for contacting a test point on a circuit board. One of the plungers (30) has a hollow receptacle (34) extending into the barrel (22) with a rectangular or notched keyway (44) opening into the receptacle. The keyway (44) is disposed at an angle of about 6 DEG to the longitudinal axis thereof. The other plunger (50) has a twisted guide member (54) extending through the barrel into the keyway (44) of the other plunger whereby axial translation of the plungers (30,58) relative to each other also causes a rotation thereof and the keyway (44) rides in the groove (56) for electrical contact as translational movement occurs. A leafspring is further provided on the hollow receptacle (34) adjacent the notched keyway for contacting the twisted guide member (54) of the other plunger to minimize electrical resistance during axial translation. In addition, the plunger (30) may have an open end extending from the barrel (22) with inwardly directed fingers for engaging a contact tip for retaining the same therein.