Hardness tester

Patent metadata

Field	Value
Publication number	US-11073456-B2
Application number	US-201916589513-A
Country	US
Kind code	B2
Filing date	Oct 1, 2019
Priority date	Oct 3, 2018
Publication date	Jul 27, 2021
Grant date	Jul 27, 2021

Abstract

A test force generating spring that is interposed between an indenter shaft provided with an indenter at a distal end and a press that linearly displaces the indenter shaft toward a sample stage so as to press the indenter into a surface of a sample is configured as an annular spring having left/right symmetry, the annular spring including a left/right pair of through-holes that are formed running from one side surface of a substantially rectangular metal block to another side surface on a rear side of the block and a slit that is formed so as to connect the pair of through-holes. With this configuration, a highly accurate test force can be generated and a hardness test can be favorably performed by a hardness tester.

First claim

What is claimed is:

1. A hardness tester for measuring hardness of a sample, the hardness tester comprising:
a stage on which the sample is placed;
an indenter shaft having an indenter at a distal end thereof;
a press that linearly displaces the indenter shaft toward the stage so as to press the indenter into a surface of the sample;
a test force generating spring having a left/right symmetrical shape and positioned between the press and the indenter shaft, the test force generating spring comprising:
a left/right pair of through-holes that are formed running from one side surface of a substantially rectangular metal block to another opposite side surface of the block; and
a slit that is formed so as to connect the left/right pair of through-holes;

a spring displacement detector that detects a displacement amount of the test force generating spring that occurs when the indenter is pressed into the sample via the indenter shaft; and
an indenter shaft displacement detector that detects a displacement amount of the indenter shaft that occurs when the indenter is pressed into the sample,
wherein the indenter shaft is fixed to an approximate center of a bottom surface of the test force generating spring, and the press is fixed to an approximate center of a top surface of the test force generating spring.

2. The hardness tester according to claim 1 , wherein a groove that follows the left/right pair of through-holes is formed in at least one of the top surface and bottom surface of the test force generating spring.

3. The hardness tester according to claim 2 , further comprising:
a plurality of vertically stacked through-holes, each comprised of the left/right pair of through-holes and the slit, provided to the test force generating spring in a vertically stacked arrangement, and
a pair of parallel through-holes and a dividing slit, each provided between the vertically stacked through-holes, wherein:
the pair of parallel through-holes are formed to follow the left/right pair of through-holes, and
the dividing slit is formed so as to vertically divide a region at the outside of the pair of parallel through-holes.

4. The hardness tester according to claim 1 , further comprising:
a plurality of vertically stacked through-holes, each comprised of the left/right pair of through-holes and the slit, provided to the test force generating spring in a vertically stacked arrangement, and
a pair of parallel through-holes and a dividing slit, each provided between the vertically stacked through-holes, wherein:
the pair of parallel through-holes are formed to follow the left/right pair of through-holes, and
the dividing slit is formed so as to vertically divide a region at the outside of the pair of parallel through-holes.

Assignees

• Mitutoyo Corp

Inventors

• Kawazoe Masaru

Classifications

• G01N2203/0035

  Spring · CPC title

• G01N3/02

  Details · CPC title

• G01N3/44 Primary

  the indentors being put under a minor load and a subsequent major load, i.e. Rockwell system · CPC title

• G01N3/42 Primary

  by performing impressions under a steady load by indentors, e.g. sphere, pyramid (G01N3/54 takes precedence) · CPC title

• G01N2203/008

  Residual indentation measurement · CPC title