GB1069365A - Improvements in or relating to sclerometer apparatus - Google Patents

Abstract

1,069,365. Schlerometers. S. IMAI. Sept. 21, 1964 [Sept. 20, 1963], No.38478/64. Heading G1S. A schlerometer apparatus for measuring the hardness of a specimen 16 comprises a platform 15 elevated by a niotor 10 and magnetic clutch 12, an indentation member 17 for engaging the specimen when it is placed in position on said platform, a rod 18 carrying said punch, means for supporting said rod and for resiliently loading said rod, a pivoted lever 21 engaged by a portion of said rod remote from said punch, and an indication assembly (Fig. 5) comprising a pivoted pointer 25 for sweeping over a graduated dial 24, the lever 21 and the pointer being connected so that movement of the lever causes rotation of the pointer. The apparatus also comprises lever switch means 28 actuable by displacement of the lever 21 into an extreme position thereof, a photo-electric cell switch unit (Fig. 6) mounted with respect to the indicator dial, and comprising a light source 30 and a photo-electric cell 31 spaced from said light source and mounted adjacent the zero graduation on said dial, a mask 29 pivotally mounted for rotation around said dial in synchronism with said pointer so that it passes between the light source and the photo-electric cell when the pointer is in registry with the zero graduation, a control circuit comprising the lever switch means 28 and the photo-electric cell switch, and relay means connected for actuation by said control circuit and adapted to de-energize and stop movement of the motor and clutch unit when the control circuit is actuated. When the test specimen is moved upwardly, it engages the indentation member 17 which is in turn moved upwardly against the action of a spring 20. The movement of the indentation member tilts a lever 21 causing the pointer 25 to rotate about its pivot, indicating the vertical displacement of the indentation member on the dial. As the indentation member 17 approaches its uppermost limit, the lever switch 28 is closed by contact with one end of the lever 21. The mask 29 is attached fixedly to the pointer 25 on the opposite side of the dial plate 24 so that as soon as the mask intercepts the light source 30 of the photoelectric cell switch the controlled circuit is closed provided the switch 28 is closed, this position of the pointer corresponding to the zero mark of the scale 27, the motor and clutch mechanism being thus stopped immediately. Thus at the uppermost extreme position of the indentation member 17 the pointer 25 will coincide exactly with the zero of the scale 27. A lever 41 is then released to add a further load to the indentation member, driving the member 17 deeper into the test specimen, the position of the pointer thus reached being a measure of the hardness of the specimen.