Surface-following cartridge for use with linear measurement transducer systems

Claim 1

Surface-contacting electronic micrometer gage apparatus for linearly measuring surface contours, comprising: a transducing measuring system including an elongate transducer member having an active element providing an electrical output proportional to variations in the displacement of the element from the surface of a conductive material an elongate tubular casing having one of its end portions detachably receiving (adapted to retainably receive) said active element, means for adjusting the received length of said transducer member (portion), a plunger reciprocably mounted in the other end portion of said casing, said plunger having an inner end portion formed of a conductive material and an outer end portion adapted to contact and follow a surface to be measured, resilient means reciprocably urging said plunger outwardly of said casing, and abutment means carried by the casing for physically limiting the extent of the resiliently-urged (limiting the) outward travel of said plunger, whereby said transducer member can be adjustably disposed in said casing with its active element fixed a spaced distance from said conductive material at the inner end of the plunger for physically limiting its inward reciprocal movement, said outer end of the plunger projecting outwardly of said casing at said inward limit for resiliently following contacted surface contours, said spacing of said (transducer) active element being fixed in accordance with the displacement range of the transducer member and said electrical output of said (transducer) active element varying responsively to the variations in said spacing produced by said surface following plunger.