Touch signalling probe

Claim 1

A touch signalling probe comprising: a probe shaft having a pointed end; a touch sensor on the pointed end of said probe shaft; a insulated contact base plate fixed to a probe case and having an aperture in the center through which said probe shaft can be penetrated; two sets of upper contact pair attached on the upper side of said insulated contact base plate, each set of which has two contact members arranged in the vicinity in the insulated state, and which are symmetrically located with respect to said probe shaft; two sets of lower contact pair attached under the reverse side of said insulated contact base plate, each set of which has two contact members arranged in the vicinity in the insulated state, and which are located in the direction of a right angle against said two sets of upper contact pair; two upper contact arms insulatedly fixed to said probe shaft, and keeping contact over with each of contact members of both said upper contact pairs; a probe tube slidingly moving along said probe shaft; two lower contact arms insulatedly fixed to said probe tube and keeping contact over with each of contact members of both said lower contact pairs; a spring insulated between said probe shaft and said probe tube in order to provide urging force by which said upper contact arms and said lower contact arms put to maintain said upper contact pairs and said lower contact pairs between said upper contact arms and said lower contact arms; and detecting lead wires connecting said respective contact members in series.