Patent GB-190420134-A (GB)
Title: Improvements in Controlling Apparatus for Electric Motors for Working Lifts and like Apparatus.
Inventor: KLINKENBERG JOHN
Filed: 1904-09-19
Granted: 1904-11-03
Abstract: 20,134. Klinkenberg, J. Sept. 19. Lifts; electrically-actuated apparatus ; overwind ing, preventing.-Relates to controlling-devices for electric motors principally intended for working lifts. The shaft of the winding-drum is connected by bevel gearing B<1> to a screwed shaft A carried in bearings A, A, and upon which works a nut C so as to travel upwards and downwards on the shaft, its rotation being prevented by an arm C' connected therewith and provided with a curved end fitting a fixed rod C'. Above the nut, and held to it by a coupling D' screwed on the nut, is a loose sleeve D, having a feather D<3> which works in a longitudinal groove in the shaft, so that the sleeve not only rises and falls with the nut but rotates with the shaft. Adjustably secured to the sleeve by nuts E' is a toothed disc E. One switch device, as shown on the left of Figs. 1 and 2, is arranged to correspond to each floor at which it is desired the automatic stopping of the lift shall or may take place. It consists of a sector H<1>, having teeth H' operated by the toothed disc E, two cam-surfaces H<5>, H<6>, two star teeth H<7>, H<8>, and a pin H. A pin J<1> engages with the cams and teeth, and is carried by a lever J<2> controlled bya spring J<3>. The pin H works between the forked ends G<6> of a lever pivoted on a pin G', and connected by springs G<7>, G<8> to another lever G' pivoted on the same pin. The latter lever is provided with two blades G which serve to make contact with the contacts G', G<2>. As usual, the switch bears on one contact when the button is pressed to cause the lift to ascend, and on the other to descend. When it is between the two, the circuit is broken, the motor is cut off from the supply, and the brake is applied. The switches for the several floors are arranged one above the other, so that, when the lift is travelling and reaches any particular floor, the rotating disc E will be opposite the mechanism and switch for that floor. If all the switches are in the position shown, and the lift commences to descend, the disc will rotate in the direction indicated and throw each switch in succession to the middle or open position. If any of these is in the electric circuit, the circuit will thus be broken and the lift brought to rest. If any are not in circuit, no effect is produced except that the switch is thrown over to the other contact G<2>, the lift going on further. A roller holds the switch steady on either contact by hearing on the cam-surfaces H<5> or H<6>. To cause the lift to ascend, the switches must be upon the contacts G<2>, The device may be employed solely to prevent overrunning at the top and bottom, in which case only two switches are required, and only one contact G<1> or G' is required for each. Two discs such as E may be mounted on a longer sleeve D, one to act on the upper switch, the other on the lower, thereby allowing of finer adjustment. Ordinary spring-controlled tumbler switches may be used instead of the one shown. The hoisting- rope passes as usual over a pulley carried by a weighted bell-crank lever, which is connected to an arm adapted to actuate one of the switches in the controlling-mechanism, thus obviating the use of a separate switch, as usually used, in case the rope should break or slacken.