GB237390A - Hoisting engine controls - Google Patents

Abstract

237,390. Lilly, W. J., and Logan, H. H. May 26, 1924. Overwinding and overrunning, preventing, and emergency power cut-off gear.- Comprises mechanism in which a cam or the like the movements of which correspond with those of the cage, operates end stop gear, and a centrifugal governor operates over-speed stop gear, the stop means including a circuit having a switch which may be opened by the governor and a pair of switches either of which may be opened by the cam. A cam disc 9 positively rotated from the winding drum carries a pair of retarding cams 10, 11, one for each direction of rotation, final stop cams 14, 15, a cam for operating a warning bell 74 just before the end of the wind, and a pair of cams additional to the retard ing cams for slowing down the cage at an earlier point when men are being carried. The last cams are brought' into use by means which also impose a lower speed limit than that normally imposed by a centrifugal governor 29. The governor, which is controlled by a dashpot 47 and an adjustable weight 48, operates a lever 38 carrying a contact member 63. When the speed becomes excessive this member rises and makes contact with a spring member 64, so closing an alarm bell circuit. If the speed still rises, the member 63 compresses the spring 64 and raises a pivoted arm 50, Fig. 4, to open switch contacts 52, 54 of a circuit controlling the hoisting engine and the brakes. The contacts 52, 54 are carried by an arm 49 connected to a lever 69 having a roller 70 acted upon by one of the retarding cams according to the direction of movement of the cage. The effect of this is to bring the arm 49 and the spring contact 64 nearer to the governorcontrolled contact 63 and so to lower the speed at which the governor acts. At the end of the wind one of the stop cams 14, 15 acts on a roller 28<a> or 27<a> and opens another switch 22 or 21 in the circuit controlling the engine and the brakes. For carrying men a lever 102, Fig. 3, is raised or lowered from the central position shown and (1) rocks an arm 97 on the axis of the roller 70, thus bringing one of a pair of rollers 98 into the path of an additional retarding cam (not shown) which acts at an earlier stage than the main cam 11. and (2) lowers the switch-carrying arm 49 so that the governor will act at a lower speed. At the same time the lever 102 closes switch contact's 106 or 107, giving notice through lamps to the engineer and the men at the top and bottom of the shaft that' the additional safety control is in action. The various cams are adjustably secured to the disc 9. Specification 152,466 is referred to.