Abstract: The hardness meter is so designed as to render the applied measurement load independent from the force that the operator is capable to exhert and as to provide an instantaneous load permitting a precise measure even if the equipment is shifted during the operation. Such hardness meter includes, between the mobile structure operated by the user's hands and the penetrating pin, a device capable of exherting an instantaneous force on the penetrating pin.This device is formed by a plated spring (49) carried by an inertia mass (45) sliding along the guiding columns (10 and 11) and presenting a convexity which may be released from one side to the other of the median plane; when it is arranged on one side of the plane it is loaded and when it turns to the other side provides the instantaneous force which throws along said columns the inertial mass braked, however by friction means (50, 51 and 52) thus preventing the discharge of the reaction forces against the operator's hands.

Abstract: An apparatus and method for measuring the flow stress and like characteristics of metals and other material especially at hot working temperatures. The specimen is struck simultaneously by projectiles of equal mass but unequal velocity. The velocities of the projectiles and the dimensions of the different indentations produced upon the specimen by the projectiles are terms in the formula by which the flow stress is calculated. A formula requiring only two projectiles is adequate for many materials; one requiring three projectiles may be better for materials that show work-hardening when they undergo strain at high temperature. The projectiles may be propelled pneumatically or by contact with a driven lever. Alternatively the projectiles may be in the form of masses carried as pendulums.

Abstract: A powder-actuated apparatus for determining the hardness of various homogeneous materials wherein the determination may be made in a manufacturing facility, warehouse, or in the field. The apparatus ensures that a constant driving force will be delivered to a testing probe without the need to carefully control the energy input source for the apparatus. Thus, conventional cased or caseless powder charges can be used as the initial energy source for the apparatus.

Abstract: A method for performing strength tests on material to be mined includes the steps of preparing a flat surface on the material to be tested, forming one or more grooves in the flat surface, impacting the flat surface with a test device at a predetermined angle and at a predetermined force which is at least as great as that necessary to break out material located between the impact point and groove, repeating the preceding step at a predetermined distance from the first impact, at substantially the same force and at substantially the same angle.An impact guide and sample collector guides the test device toward the test surface at a predetermined angle and collects material broken out during the test.

Abstract: A coal-shale interface detector for use with coal cutting equipment consisting of a reciprocating hammer having an accelerometer mounted thereon to measure the impact of the hammer as it penetrates the ceiling or floor surface of a mine. Additionally, a pair of reflectometers simultaneously view the same surface, and the outputs from the accelerometer and reflectometers are detected and jointly registered to determine when an interface between coal and shale is being cut through.

Abstract: The strength of a material is measured by positioning a tool against a surface of the material and driving an elongated piercing plug having a blunt front end into the material. The penetration depth of the piercing plug is proportional to the material strength. A trigger on the tool for releasing the piercing plug for driving movement into the material requires manual force acting through the trigger on the tool in a direction for maintaining the front end portion of the tool in engagement with the surface of the material being tested.

Abstract: A coal-shale interface detection system for use with coal cutting equipment consisting of a reciprocating hammer having an accelerometer mounted thereon to measure the impact of the hammer as it penetrates the ceiling or floor surface of a mine. Additionally, a pair of reflectometers simultaneously view the same surface, and the outputs from the accelerometer and reflectometers are detected and jointly registered to determine when an interface between coal and shale is being cut through.

Abstract: A penetrometer for coal-shale interface detection for use with coal cutting equipment consisting of a reciprocating hammer having an accelerometer mounted thereon to measure the impact of the hammer as it penetrates the ceiling or floor surface of a mine. Additionally, a pair of reflectometers simultaneously view the same surface, and the outputs from the accelerometer and reflectometers are detected and jointly registered to determine when an interface between coal and shale is being cut through.

Abstract: In apparatus for measuring the hardness of rubber of the type wherein a needle is urged against the surface of a rubber sample and the degree of penetration of the needle is measured there are provided a coil spring, a lever for causing the needle to compress the spring and a releasable latch for holding the spring in the compressed state. When the spring is released it urges the needle against the rubber sample under a prescribed speed and force. The displacement of the needle is detected by an electric transducer and its output signal is processed by an electric circuit including a peak detector and an analogue-digital converter for digitally displaying the displacement. When the spring is released a switch is operated to start the analogue-digital converter for determining the starting point of the time necessary to measure the displacement by using the time as a parameter.