| 摘要 |
990,746. Machinery safety devices. LICENTIA PATENT - VERWALTUNGS - G.m.b.H. Jan. 23, 1962 [Jan. 26, 1961; May 4, 1961; Aug. 11, 1961; Dec. 27, 1961], No. 2401/62. Drawings to Specification. Heading F2J. [Also in Divisions G3, G4, G6, H2 and H3] A transistorized binary control circuit (see Division H3) which uses A.C. signals throughout so that the circuit fails safe in the event of a transistor becoming defective may be used to control the safety guard on a machine press. For this purpose a light curtain is used the light from which is alternating or pulsed so that the output signal from the photo-electric pick-up also alternates and no output signal is produced in the event of the photo-electric pick-up becoming defective. |
