| 摘要 |
1,118,233. Magnetic tests. A.K. LITTWIN and D.F. LITTWIN. Dec. 3, 1965 [Jan. 12, 1965], No. 51454/65. Heading G1N. Magnetisable articles (the magnets for drag-cup speedometers) are sorted by magnetising them, measuring the remanent flux, automatically removing those with a remanence below a datum value, and de-magnetizing both the accepted and rejected articles. The articles are fed from a storage hopper Figs. 1 and 2 (not shown) by a vibrating conveyer on to a conveyer belt which carries them successively over a D. C. energized, magnetizing coil (64), Fig. 5 (not shown), over the rotating armature (70) of a flux meter Fig. 6 (not shown), past a reject chute Fig. 7 (not shown) into which they may be propelled by a jet of compressed air controlled by a solenoid valve (136), and over an A. C. energized de-magnetizing coil (82) before dropping off the end of the conveyer. The rejected articles are de-magnetized by a coil (80) which surrounds the reject chute. The solenoid valve (136) is normally energized to reject any item on the conveyer, but is deenergized by opening the contacts (134b) of relay (134) in the anode circuit of a thyratron (124) which fires when the rectified output voltage of the flux meter (70) exceeds a pre-set reference voltage. Under these conditions the solenoid valve (136) is kept de-energized by opening the contacts (144c) of a relay (144) which is controlled by a time delay thyratron (142) the time constant of which can be varied by capacitor (146) so that after an acceptable article has been tested, the solenoid valve (136) remains de-energized until just after the next article reaches the flux meter. The voltage applied to the capacitor (146) may be varied simultaneously with the speed of the conveyer belt Fig. 9 (not shown).
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