Patent ID: 7066013

Claim:
A hardness tester for measuring a hardness of a tested object having a testing surface, comprising: a supporting frame comprising a hand-held casing having a receiving chamber, a driving wheel rotatably mounted to said hand-held casing, and a tubular guiding cylinder having an elongated guiding channel extended from said hand-held casing at a position that said guiding channel is coaxially extended to communicate with said receiving chamber; a driving axle slidably disposed in said receiving chamber of said supporting frame; a gear unit supported in said hand-held casing to operatively couple said driving wheel with said driving axle in such a manner that when said driving wheel is rotated, said driving wheel is adapted for applying a penetrating force on said driving axle through said gear unit; a penetrating pin, having a pin head, coaxially disposed in said guiding channel in a slidably movable manner to coaxially align with said driving axle for said pin head to penetrate on said testing surface of said tested object; and a linear displacement device, comprising a transmission shaft slidably disposed in said receiving chamber to end-to-end contact between said driving axle and said penetrating pin, and a displacement sensor supported in said receiving chamber for detecting a linear displacement of said transmission shaft, wherein when said transmission shaft transmits said penetrating force from said driving axle to said penetrating pin, said linear sensor detects said linear displacement of said transmission shaft in response to said penetrating pin for measuring, said hardness of said tested object.