GB348915A - Improvements in hardness testing machines - Google Patents

Abstract

348,915. Testing hardness of materials. WILSON, C. H., 68, Young Avenue, Pelham, Westchester, New York, U.S.A. June 10, 1930, No. 17836. Convention date, April 16. [Class 106 (ii).] In a hardness-testing machine of the kind in which a minor load is first applied to a penetrator resting on the test piece, and then a major load to cause penetration into the.test piece to an extent which determines the hardness, the penetrator member is, when in operative position, guided only by contact with the test piece, and at a point near its opposite end. The test piece is mounted on the top of an elevating screw 11, below a penetrator 43. The head of the machine comprises a web 22 secured to pillars 18, 19 and having side flanges 23 between which is arranged a lever 90 pivoted at 91 for the application of the major load by means of weights 98. A block 50 is mounted between the flanges 23 and is formed with an opening having rounded edges to receive and guide a rod 35 carrying the penetrator 43. The upper end of the rod actuates a pivoted lever 55 which operates an indicator 61 provided with a manually rotatable bezel 65 for adjustment to zero. A bush 75 is slidably mounted on the rod 35 and is pressed upward by a spring 80 to hold it away from the plunger 36. An intermediate sleeve 85 is adapted to transmit pressure from the lever 90 to the bush 75 and thence to the plunger 36. A lever 100 is adapted by means of a link 102 and roller 103 to lift the lever 90 when actuated at its opposite end by means of a hand-operated crank 107 pivoted at 105. A dashpot 115 is adapted to permit quick raising of the lever 100 and to retard its falling. In operation, the lever 90 is lifted to support the load, and the test piece is raised against the penetrator 43 until the plunger 36 is lifted off its seating 33 and the spring 80 is compressed to apply the minor load. The needle of the indicator is then set to zero, and the penetrator and associated parts are supported only at the penetrating point and at the block 50. The lever 90 is then released by movement of the crank 107 and the major load is applied through the sleeve 85 and bush 75 to the plunger 36 and penetrator 43.