Abstract: A semi-automatic penetration hardness tester for measuring hardness of a test specimen in a selected one of a number of hardness number scales. A digital display indicates penetrator displacement during application of a minor load in a first mode of operation and may be monitored by an operator to achieve a penetrator displacement within a preselected range corresponding to application of a minor load of desired magnitude. A control circuit senses manual initiation of a major load application and automatically scales the minor load penetrator reference position to a reference hardness number corresponding to and correlated with the selected hardness number scale. The control circuit also senses an operator error during the test procedure and automatically aborts the test.

Abstract: A reference-load variable hardness tester for measuring Rockwell hardness and Rockwell superficial hardness, having an internal coil spring and an external coil spring disposed coaxially with a load shaft for each reference-load. When measuring Rockwell hardness, both the internal coil spring and the external coil spring work for the reference-load, and when measuring Rockwell superficial hardness, only the internal coil spring works for the reference-load.

Abstract: An apparatus for positioning a loading shaft of hardness tester prior to application of test load. A loading shaft position detector is provided for detecting the arrival of the loading shaft at a given position when elevating it, and the detector controls an electromagnetic means to check further continuation of the elevating operation of the loading shaft so that the loading shaft is set automatically at the given position. An electromagnetic clutch or brake serves as the electromagnetic means.

Abstract: Hardness tester adaptable to automatic testing of rubber comprising sample support surface, indentor perpendicular to the surface slidably movable within a housing, means for introducing gas under pressure between the indentor and the housing to laterally support the indentor while the sample is subjected to the weight of the indentor only, foot providing a flat datum surface normal to the indentor and with space through which the indentor is movable, means for lowering the foot and indentor in contact with the sample, means to increase the weight on the indentor and means to indicate its downward movement.

Abstract: An apparatus for testing the hardness of a workpiece has a lower structure having a surface defining a reference plane from which can project an axially displaceable penetrator. A preload spring biases the penetrator with a relatively small preload force into a position projecting from the plane. Upper structure adapted to receive an applied load force directed axially toward the lower structure is displaceable through a long axial distance between an upper rest position relatively far from the lower structure and a lower position directly abutting the lower structure. Intermediate structure is axially displaceable between the upper and lower structures toward the upper structure from a lower position resting on an abutment fixed on the upper structure.

Abstract: A hardness testing machine comprises an indenter mounted on one end of a lever. A workpiece clamp is mounted on a further lever to engage the same face of the workpiece as is engaged by the indenter. A piston andcylinder unit is arranged to transfer to the indenter lever a load normally borne by the clamp lever so that load on the workpiece is unchanged. Movement of the indenter arising from the temporary application of the additional load is amplified and applied to a dial gauge.

Abstract: A deformeter for testing the firmness of fruit as an indication of its maturity includes a support for an individual fruit effective to convey the fruit to a testing location, at which sensors are urged to contact the fruit surface lightly, preferably on a diameter, to establish a datum position. The sensors are then urged to contact the fruit with a predetermined, deforming pressure. At least one more sensor moves correspondingly into the fruit to establish an indented position. The two sensor positions are electrically noted and are subtracted to afford an indented distance from datum position indicative of firmness and so maturity. A modification uses a pair of first sensors arranged on opposite sides of the fruit in a trailing position, the pairs operating in sequence and being arranged with all sensors substantially in the same, vertically adjustable plane.

Abstract: A Rockwell hardness tester having a load application mechanism having a load transfer unit divided into an upper transfer member and a lower transfer member having bores through which an indenter shaft of the tester extends axially with some play. The transfer members are disposed coaxially and have a pair of balls therebetween horizontally arranged in a direction perpendicular to a knife edge on an upper end of the upper transfer member supporting a load application lever. The load transfer unit rests on a spring support cylinder with an initial load spring circumferentially thereof and having its lower convolutions resting on the expanded portion of the indenter shaft and the load applied to the tester is accordingly never applied eccentrically to the indenter shaft.

Abstract: An improved tester for measuring the hardness of materials, the tester having multiple spring means and an adjustable control for placing one or both of the spring means into operation to load the tester under different minor loads.