| 摘要 |
PURPOSE:To make it possible to certainly measure the hardness of a casting mold, by a method wherein an indenter projected from the lower surface of a base stand through a spring is pressed to the surface of the casting mold and the movement thereof toward the penetrating direction is converted to rotary motion which is, in turn, read by two kinds of graduations of AFS hardness and NIK hardness. CONSTITUTION:An indenter 2 having a spherical surface at the leading end thereof is projected from a base stand 1 having a flat surface 1A at the lower surface thereof by a spring 3. When the flat surface 1A is closely contacted with the surface of a casting mold, the leading end 2A of the indenter 2 is partially penetrated into the casting mold and slightly pushed in the base stand 1. The latter movement is enlarged by a rack 4, a small diameter gear 5, a large diameter gear 6, an intermediate small gear 9 and an intermediate large gear 10 and converted to the rotation amount of a pinion 7. Because the intermediate large gear 10 is lacking in the half of teeth, the pinion 7 is not rotated by the movement of the indenter in AFS hardness of 50 or less. Both AFS and NIK hardnesses can be simultaneously read from the AFS hardness graduations 11A and NIK hardness graduations 11B graduated on a dial plate 11 by the indicator 8 attached to the pinion 7. |
