GB612084A - Improvements in or relating to mechanism for lifting and lowering cradles - Google Patents

Abstract

612,084. Winding and paying-out apparatus. LONGWORTH, J. R. Aug. 17, 1946, No. 24539. [Class 78 (v)] A cradle 10 of the type used by workmen for access to the wall of a building is lifted and lowered by a cable 12 secured to the cradle harness 11, passing over a fixed pulley 13, into a drum 15 where it passes over a hauling pulley turned through gearing by a handle 21a, from the drum over a pulley 27 which may be braked against rotation, round a weighted tensioning pulley 34 and to a storage drum 32 which may also be braked. A centrifugally operated brake limits the speed of the haulage pulley in descent. The handle 21a is secured to a wheel 21 keyed to a shaft 17 (Fig. 2) in the housing 15, on which is secured a centrifugally operated internal expanding shoe brake 24 adapted to engage a fixed drum 25 and the sun-wheel 20 of an epicyclic train 20, 19, 18 of which the planet carrier is fixed and to the annulus 18 of which is secured the hauling pulley 16. The cable 12 is led into and out of the housing 15 over pulleys 26 arranged to provide a large arc of contact on the pulley 16. The pulley 27 may be braked to hold the cradle in position by a clamping nut 29 which presses a friction disc held from rotation against the pulley. The drum 32 may be similarly braked. A one-way clutch may be provided on pulley 27 to obviate the necessity for unlocking this before raising the cradle. Specifications 373,728 and 487,526 are referred to.