Rebound-type hardness tester
AssigneeAkashi Corporation
InventorsYasunori Sato, Junichi Arai, Yuichi Minami
Life of this patent
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Abstract
A measurement cylinder having a passage for an indenter hammer to go forward and backward formed therein is provided with two light receiving holes a distance S apart. The times required for the indenter hammer to go past the light receiving holes are measured and, in accordance with the required times measured and the distance S, the impacting velocity and the rebounding velocity of the indenter hammer are detected, whereby it is made possible to greatly improve the detecting accuracy of both the velocitys.
Claims3
A method of detecting velocitys of an indenter hammer in an Equotip type hardness tester, including a measuring cylinder constituting the body of said hardness tester and providing a passage for said indenter hammer to go forward and backward, said measuring cylinder having two light receiving holes formed therein a distance S apart in the axial direction thereof, said method of detecting velocitys of said indenter hammer in said Equotip type hardness tester comprising the steps of:
- measuring the times required for said indenter hammer to go past said two light receiving holes;
- and
- detecting the velocitys of said indenter hammer in accordance with said required times and said distance S.
An Equotip type hardness tester comprising:
- a measuring cylinder constituting the body of said hardness tester and providing a passage for an indenter hammer to go forward and backward;
- a coil spring incorporated in said body;
- an indenter hammer adapted to be shot by the spring force of said coil spring toward a specimen;
- a velocity sensor attached to said body for measuring the velocitys of said indenter hammer immediately before impacting against said specimen and immediately after the impaction;
- and
- a display unit including a CPU receiving information of the velocitys of said indenter hammer detected by said velocity sensor for calculating hardness of said specimen and a display for displaying thereon the hardness of said specimen calculated by said CPU;
- wherein
- said velocity sensor is constituted of two light projecting holes formed in the vicinity of the front end portion of said measuring cylinder a distance S apart from each other in the axial direction of said measuring cylinder and light receiving holes formed in the positions corresponding to said light projecting holes, and, further, light sources provided for each of said light projecting holes and photodetector devices provided for each of said light receiving holes.
Dependencies are inferred from the claim text.