METHOD AND APPARATUS FOR A HARDNESS TEST BLOCK ALIGNMENT

Abstract

A combination of a unique test block and a modification of the anvil on a hardness testing machine wherein the combination enables the testing block to easily and quickly align with the indenter of the hardness testing when said testing block is placed on the hardness testing machine's anvil. At least one spring-loaded ball detent is provided that enables the test block to be positioned using one of a plurality of dimples on said testing block. A cradle is provided when a double-sided test block is used to keep the surface of the test block from being marred when said testing block is placed on the anvil. An alternative embodiment uses more than one detent on the anvil which keeps the test block from rotating while the test block is on the anvil.

Claims

1. A combination of a hardness test bock and a hardness testing apparatus having an anvil, an indenter that is adapted to produce a preselected force for a predetermined period of time on a test site wherein said combination comprises: the test block having a plurality of test sites on one side of said hardness test block forming a grid pattern and a plurality of dimples on the opposite side of said hardness test block wherein each dimple is directly opposite to and aligned with one of said plurality test sites on said grid pattern; the anvil of the hardness testing apparatus comprising at least one spring-loaded ball detent aligned with the indenter of the hardness testing apparatus such that when said detent engages with one dimple on said hardness test block, the test site corresponding to that dimple is positioned beneath the indenter and aligns the grid pattern of the test block with the hardness testing apparatus quickly and accurately.

2. A combination of a hardness test bock, a cradle, and a hardness testing apparatus having an anvil, an indenter that is adapted to produce a preselected force for a predetermined period of time on a test site wherein said combination comprises: a test block having a plurality of test sites on one side of said hardness test block forming a first grid pattern and a plurality of test sites on the other side of other side of said test block forming a second grid pattern; the cradle dimensioned to hold the test block wherein said cradle further comprises a plurality of dimples on the side of the cradle that is adjacent to the anvil of the testing apparatus such that each dimple's position aligns with the center of a corresponding test site grid such that the indenter is centered within the test site; the anvil of the hardness testing apparatus comprising at least one spring-loaded detent aligned with the indenter of the hardness testing apparatus such that when said detent engages with one dimple on said cradle, the test site corresponding to that dimple is positioned beneath the indenter and aligns the grid pattern of the test block with the hardness testing apparatus quickly and accurately and the use of the cradle prevents the test sites from contacting the anvil during the testing operation thus preventing marring of the testing surfaces.

3. The combination of claim 1 wherein at least two spring-loaded ball detents are provided such that the test block is prevented from rotating when the at least two detents are engaged in the least two dimples in the test block.

4. The combination of claim 2 wherein at least two-loaded detents are provided such that the cradle with the test block inserted therein is prevented from rotating when the at least two detents are engaged in the at least two dimples in the cradle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1A is front view of a test block with a plurality of dimples in a typical test block wherein a spring-loaded detent in an anvil of a typical hardness test machine can be used to align the test block with the indenter of the hardness test machine.

[0022] FIG. 1B is a top view of the test block shown in FIG. 1A.

[0023] FIG. 2A is a front view with a double-sided test block being supported by a cradle, which is provided with a plurality of dimples for alignment with a detent in the anvil of a typical hardness test machine.

[0024] FIG. 2B is a top view of the test block shown in FIG. 2A.

[0025] FIG. 3A is an alternative embodiment of the invention showing a front view of a plurality of detents in the anvil of a typical hardness test machine.

[0026] FIG. 3B is a top view of the alternative embodiment shown in FIG. 3A.

[0027] FIG. 4 is an exploded isometric view of a test block and a supporting cradle.

DETAILED DESCRIPTION OF THE INVENTION

[0028] While the test block used in the invention is preferably the type disclosed and claimed in U.S. patent application Ser. No. 15/407,559, the techniques and methods used herein can be applied to any test block as shown in FIG. 1.

[0029] Shown in FIG. 1, a plurality of dimples 24 is provided in the bottom surface of test block 10, which rests on anvil 20. The plurality of dimples 24 is aligned with the predetermined test sites on the opposite side of test block 10.

[0030] Dimples 24 can be placed so that the centers of the dimples 24 are coincident with the centers of test sites 26 as shown in the accompanying figures. Also, dimples 24 can be aligned so that they fall between the centers of the test sites (not shown).

[0031] Detent 22 which can be spring-loaded is set in the center surface of anvil 20 of a typical hardness test machine (Not Shown) which is well known in the art. If the centers of dimples 24 are spaced between the centers of test sites 26, then the position of detent 22 must be offset accordingly so that when detent 22 engages one of dimples 24, the center of test site 26 being used is aligned perfectly with the indenter of the hardness test machine. In this manner, when detent 22 engages one dimple 24, test block 10 is properly aligned with the appropriate test site 26 as shown.

[0032] While test site 26 is shown as having a greater diameter than dimple 24, this is not necessary, and it could be just the opposite. Also, test sites 26 could be marked with indicia identifying the test sites and marked or etched on test block 10, which will facilitate ease of aligning a particular dimple 24 with detent 22.

[0033] If a double-sided test block 10 is used in accordance with the teachings of U.S. patent application Ser. No. 15/407,559, then cradle 12 should be used to keep the non-test side of test block 10 from contacting anvil 20 during the testing process. This is necessary to prevent any marring of the non-tested surface, which would prevent both sides of test block 10 from being used. This is shown in FIGS. 2 and 4. Note that when using a double-sided test block, dimples are not provided in the test block, as this would interfere with proper testing on both sides of the block.

[0034] Cross members 18 of cradle 12 hold the test surface away from anvil 20 while the opposite surface is being used. Recess 27 is provided in cradle 12 so that test block 10 is securely held in position while being supported as shown in FIGS. 2, 3, and 4. While two cross members 18 are shown, more or less could be used, again depending on the configuration of test block 10 and the expected forces that will be applied to test block 10. Cradle 12 could also be round when used with round test blocks.

[0035] An alternative embodiment of the invention is depicted in FIG. 3 shown with a double-sided test block. While a single detent 22 would position test site 26 properly aligned with the indenter of the test machine when the centers of dimples 24 are coincident with centers of test sites 26, this might not be the case when dimples 24 are offset from the centers of test sites 26 since test block 10 (or when in cradle 12) is free to rotate around a single detent 22. Therefore, by the addition of one or more detents 22 as shown in FIG. 3, test block 10 (or when in cradle 12) is locked into position and can no longer rotate.

[0036] Although the present invention has been described with reference to certain preferred embodiments thereof, other versions are readily apparent to those of ordinary skill in the preferred embodiments contained herein.