GB590976A - Improvements in or relating to lifts - Google Patents

Abstract

590,976. Lifts. EXPRESS LIFT CO., Ltd., and DIXIE, W. A. April 27,1945, No. 10654. [Class 78(ii)] The cage of a lift has means for the ready attachment to its under side of one or more weights, so that the amount the counterweight exceeds the weight of the' empty cage can be reduced and the lift thereby adapted for faster running on light loads. As shown, the weight 4 normally rests on supports 16 at the foot of the liftshaft, and can be picked up by the cage 1 by bringing it below the lowest level served and into contact with stop buffers 20. In this position, a fixed cam 24 depresses a rod 21 on the cage to unlock a trap-door 19 giving access to a control lever 10 by which pivoted stirrup members 7, 8 are rocked to engage bosses 17 on the weight. 'One or more further weights may be disposed alongside the weight 4 to be simultaneously picked up by further pairs of stirrups similar to 7 and 8 and connected for operation with them. The speed of the lift is automatically controlled according to whether or not the weights are attached. For this purpose the control lever 10 carries an apertured plate 34 controlling movement of spring actuated plungers 31, 39 having cams 35, 36 and 42, 43 for actuating low and high speed switches 37, 38 and 44, 45 alternatively. In Fig. 5, the lever 10 is positioned for disengaging the weight, and an aperture in the plate 10 registers with plunger 31 which is moved by its spring /32 to release cams 35 and 36 from switches 37, 38 which accordingly close the circuit for low-speed running. In the other position of the lever, in which the stirrups are engaged with the weight, plunger 31 is retracted to break the low-speed circuit and plunger 42 operated to close switches 44, 45 for the high-speed drive. In intermediate positions of the lever, both switches are open and the lift cannot operate. The control circuit is also broken by a switch 29 when the trapdoor 19 is open.