| 摘要 |
1,223,181. Hardness testing: pneumatic gauge. GKN GROUP SERVICES Ltd. July 9, 1969 [April 11, 1968], No.17470/68. Headings G1M and G1S. In hardness testing an article e.g. a connecting rod the size of an indentation is measured or sensed by inserting the end of a hollow pneumatic probe 21 into the indentation and measuring or sensing the resistance to flow of the fluid out of the end of the probe. The end of the probe may contain a slotted spherical part 22 or a slotted conical part. The prope is mounted on a piston and cylinder arrangement such that it is held in engagement with the indentation under the pressure of springs 31, and the probe has a small transverse freedom of movement provided by balls 23 to facilitate correct alignment with the hole. Air is supplied to the gauge under constant pressure and the back pressure or rate of flow is sensed or measured. The rate of flow may be measured by a float in tube gauge having marks to index the limits of acceptable hardness. In Fig. 3 the back pressure is sensed by two diaphragms 55a, 55b which operate micro-switches 56a, 56b respectively at pressures corresponding to the limits of acceptable hardness the switches being connected to sorting apparatus. In the embodiment of Fig.4 (not shown) the back pressure from the probe is compared by two detectors 58a, 58b with two fixed pressures corresponding to the limits of acceptable hardness produced by flow lines 51, 52 including restrictors and connected to the pressure source of the probe. Each detector comprises a diaphragm which activates a switch when the probe pressure is higher than the pressure in the corresponding flow line, the switches being connected to sorting apparatus. The measuring apparatus may be included in a hardness testing machine for articles Fig. 1 (not shown) comprising a table to carry articles 9 between stations, a height sensing station 11, a grinding station 12 where a grinding wheel set at the correct height by the result from station 11 grinds a small area to a smooth surface, an indenting station 13, the indentation measuring station 14, and a sorting station 16 where articles are removed and assorted according to acceptable or unacceptable hardness from the results from the measuring station 13. |
