GB876371A - Improvements in or relating to safety devices for elevator doors - Google Patents

Abstract

876,371. Photo-electric &c. control. SCHWEIZERISCHE WAGONS-UND AUFZUGERFABRIK A.G. Dec. 16, 1957 [Dec. 18, 1956], No. 39095/57. Class 40(3) [Also in Groups XXV and XXX] Movement of a lift is prevented, unless the doors of the shaft are closed, by photo-electric, radio-active, electromagnetic or electric valve means which is operated by the closure and/or locking of the shaft doors to control the safety circuit of the lift motor. In an arrangement which is operated when the door is closed, a lamp 4, Fig. 1, and phototransistor 5 are mounted in the door frame 2 and a light guide 7 or a reflector is mounted on the door 1 so that light falls on the transistor when the door is closed. In modifications, Figs. 3, 4, 5 and 16 (not shown), the elements mounted on the door frame and door are respectively (1) two coils, one of which is energized, and a two-part core, (2) a discharge tube and a conducting plate which causes it to strike, (3) a Geiger counter and a radio-active source, (4) a ferrite member with a winding, and a permanent magnet. In an arrangement which is operated when a lock bolt is projected and the door is closed, a -sliding bolt 23, Fig. 7, is coupled to a feeler pin 29 through a driver 32 and a spring 33. A screen 28 on the driver 32 is interposed between a lamp 26 and a photo-transistor 27 carried by the feeler pin 29, when the bolt 23 is withdrawn or is projected with the feeler pin 29. When the door is closed, projection of the feeler pin is prevented. In modifications, Figs. 9 and 10 (not shown), the bolt and feeler pin carry respectively (1) a conducting plate and a discharge tube, (2) a plunger and two coreless coils. In another construction, Fig. I 1 (not shown), conducting plates carried by the bolt and feeler pin pass between two iron cores provided with primary and secondary coils. In a further construction, Fig. 13, the closing of the door is supervised by an optical system comprising two photo-transistors 60, 63 which receive light from a lamp 56 via lens 57 and prism 58, and lens 59 and prism-cum-lens 62 respectively. In a modification, Fig. 14 (not shown), the prism-cum-lens is replaced by a screen fixed to the bolt and movable between the lamp and one of the photo-transistors, while in another modification, Fig. 8 (not shown), the prisms and lenses are replaced by a screen on the bolt and a mirror on the door and only one photo-transistor. In another construction, Fig. 17, a pivoted bolt 102 carries a permanent magnet 106 which cooperates with a body 107 of magnetically saturable material above which is a magnetic shortcircuit element 110. In arrangements which are operated when the bolt is projected, (1) a screen on the bolt moves between a lamp and a photo-transistor, Fig. 6 (not shown), (2) a radio-active source on the bolt co-operates with a Geiger counter, Fig. 12 (not shown), (3) a member on the bolt moves between an electromagnet and a secondary winding, Fig. 15 (not shown).