GB642276A - Improvements in or relating to builders' hoists - Google Patents

Abstract

642,276. Builders' hoists. BARTON, C. W. G. April 28, 1948, No. 11677. [Classes 78 (iii) and 78 (v)] In a hoist of the kind comprising four main units, viz. a power-operated winch, a travelling load carrier, a mast on which the load carrier runs and which carries the head gear for the hoisting rope, and a mast platform unit to receive the foot of the mast, the last-mentioned unit has means thereon co-operating with means on the winch unit whereby these units may readily be brought into correct mutual relationship, this relationship being maintained during operation by forces derived from the tension of the hoisting rope. The handles 26, by which the winch unit a is manipulated, are adapted to bear against cut-away parts 43 at the ends of an angle-member 33 of the mast platform unit b, thereby locating these units in correct relationship. The parts are maintained in this position by the hoisting rope 32 which passes from a winding drum 3 on the unit a beneath a sheave 31 on the unit b to a similar sheave at the mast head from whence it passes down and around a sheave 42 on the load carrier unit d to an anchorage at the mast-head. The unit a is provided with a pair of wheels 16 mounted on arms 17 fast on a shaft 18. The forked end 19 of a lever 20 is pivoted at 21 to this shaft, and this lever is normally held in horizontal position by the engagement of a spring-pressed collar 22 with an aperture in a bracket 23. When the collar is released, the lever is swung outwards to clear the member 13 and is then rotated about the axis of the shaft 18 to lower the wheels with respect to the frame. In this position the lever is locked by the engagement of the collar with another fixed bracket (not shown). The shaft 4 of the drum 3 is mounted eccentrically and non- rotatably in bearings 5, each of which is drilled at 14 for the attachment of a weighted operating lever 15. A wheel 9 rigid with the drum is free on the shaft 4 and is engaged also by a brake pad 10 secured to a carrier 11 mounted on a spindle 12 having eccentric parts whereby the clearance between the pad and wheel may be varied. The sheave 13 is mounted in a swivel head 30 pivoted at 37 to a turntable 28 which is mounted in a plate 27 in the unit b. The table 28 is provided with four upstanding pins 29 to engage the lower angle posts 34 of the mast which are arranged as shown in Fig. 2. The load carrier unit d has a pair of flanged wheels 38 which engage the inner faces of the flanges of either adjacent pair of posts. Each wheel is mounted on an arm 39 which projects from the uprights 40 and is adapted to straddle the pair of flanges engaged by the wheels. A pair of rollers 41 mounted on the lower part of the carrier engages the outer faces of the flanges. Pads 45 of compressed fibre are fitted to angle members 46 attached to part of the unit d.