| 摘要 |
1,161,724. Inspecting steel strip magnetically and photo-electrically. GILLETTE CO. Oct. 13, 1967 [Oct. 14, 1966], No.46736/67. Headings G1A and G1N. In the manufacture of razor blades the steel strip is inspected for defects during the tempering and sharpening processes, and a defect is marked with a magnetic spot for subsequent detection and rejection of the marked section. The defect sensors may also actuate counters and trigger indicator flash-lamps. Defects which may be sensed are:- (i) "sweep" (curvature in the plane of the strip) by a gimbaled roller carrying a mask to vary a light beam relative to a photo-electric cell (unit (18), Fig. 2, not shown); (ii) "dish" by a vacuum head connected to a differential-transformer-vacuum-sensor (unit (20), Fig. 2); (iii) "burrs" by direct electrical contact, (unit (22), Fig.2); (iv) "width" by mechanical contact actuating an air valve, (unit (24), Fig. 2); and after sharpening by the masking of a light beam Fig. 6 (not shown) (v) "welds" by a thickness feeler actuating a switch Figs. 7a, b (not shown), to provide a magnetic mark which is subsequently detected and the welds removed (vi) "edge" i.e. quality of the honed facet by light scattered from the facet. (vii) flaws in steel detected by a "gauss meter". Edge detector Fig. 5a (not shown) a parallel beam of light shines through a masking slit on to the blade edge and a photo-multiplier and associated optical system senses light scattered at an angle of 60 degrees to the parallel beam, (the half angle at the blade tip being 28 degrees). A second detector views the other facet about 8" along the strip. The light beams are chopped by a slotted disc to provide an A. C. signal, and may be derived from a single bulb by prism reflectors Figs. 5b, 5c (not shown). Associated circuitry for processing the sensor signals, triggering the indicator flash-lamps power supplies &c. is described with reference to Figs. 8. . 10 (not shown). |
