| 摘要 |
<p>1,265,399. Cutting apparatus. CINCINNATI MILLING MACHINE CO. 9 Oct., 1969 [16 Oct., 1968], No. 49731/69. Heading B4B. [Also in Division G1] A cutting machine is stopped when breakage of the reciprocating cutting blade is detected by an inductive sensor which generates signal pulses due to the passage of the blade. As shown, material 12 conveyed by bands 10, 11 and cut by a reciprocating tool 14 moving in a guide 21 rotatable by support blocks 22, 24, as described in Specification 1,228,543. A sensorcoil 30 is arranged so that the lower end of the tool moves in and out of it. Detector circuit.-The coil 30 is connected in the tank circuit of a transistor oscillator 72 which produces an amplitude-modulated signal due to the passage of the tool, which signal is demodulated; amplified at 75; rectified, and applied as conductive bias to transistor 78 to shunt and release relay 53. Absence of modulation by the tool removes bias from transistor 78 which cuts off and relay 53 picks up to stop the machine. The-stop relay (56), Fig. 5 (not shown), may be energized by the contacts (55) of relay 53 only when the tool is in its lowest position to close contacts (57) whereby the machine is not stopped when the tool is lifted clear of the work.</p> |
