GB307217A - Improvements in automatic stopping devices for electric lifts - Google Patents

Abstract

307,217. Smith, Major, & Stevens, Ltd., and Stevens, P. H. March 13, 1928, Cage lifts. - Electric lifts which are stopped at any floor by the attendant by the projection of a solenoidactuated roller mounted on the cage into position for engagement by a ramp in the well, are provided with a cam plate which projects the roller to the required position. A solenoid A mounted on the cage is connected to one end of a pivoted arm B, the other end of which carries a cam plate C which is interposed between a roller E on a pivoted arm F carrying one member of a normally closed circuit control switch G and a second roller J<2> on a pivoted lever J which carries a roller K engageable with a ramp L in the well. To stop the cage at a floor, the attendant operates a switch to energize the solenoid and thus raises the cam plate C so that the cam D strikes the roller J<2> and projects the lever J, the flat dwell D<2> of the cam maintaining the lever in the required position independently of variation of movement of the solenoid core. On approaching the floor the ramp L pushes the lever J inwards and through the cam plate and arm F opens the switch G and thus breaks the power - circuit. Similar mechanism is provided for stopping the cage when moving upwards. To automatically stop the cage at a terminal floor, the cam plate C, Fig. 4, carries a second and oppositely arranged cam P co-operating with a second pivoted arm M, the roller N on which is engageable with a terminal ramp R. The opposed arrangement of the cams ensures the operation of the mechanism at the terminal floor if the lift has not been stopped earlier.