GB627571A - Improvements in transportable hoists - Google Patents

Abstract

627,571. Hoists. WARRY, R. F. June 18, 1946, No. 18270. [Classes 78 (iii) and 78 (v)] A transportable hoist comprises a column 2 with a pair of road wheels 10 for transporting the column when it is in a horizontal position ; the column carrying a slidable platform 38 to receive the load to be elevated and having a number of struts 23, 28, 29 which when the column is erected are expanded angularly from the column to engage the ground at their free ends to strut the column in the elevated position ; one of said struts 23 at its one end 25 being pivoted to the column and carrying a ground-engaging wheel at its other end ; and means 14 to feed the wheeled end of each strut towards the bar of the column so as to produce a pivoting of the column about its lower end and to lever it from a substantially horizontal position into its operative vertical position. Erection of the mast. When the mast 2 is horizontal and ready to be moved to another site, struts 23, 28, 29 are folded about the pivot 25 so as to lie close under the front end of the mast (as indicated in dotted lines) and the mast is then pushed forward on its rear wheels 10 and its front wheel 13. When the mast is to be erected to its vertical position, strut 23 is caused to move backwards under the mast until the mast is forced up from the horizontal to the vertical position. This is done by hand winch 33, the rope of which passes under pulley 36 (Fig. 2) round pulley 35 on strut 23 and back to a point fixed on the mast. Rotation of winch 33 thus rolls the strut on its wheel 13 towards the rear of the mast. The movement of the strut is assisted by a push on the handle 14, which is pivoted to the axle 17 of wheel 13, the frame of which pivots on pin 21 on the strut. A skid 15 which swings on a pivoted arm 15a is freed to fall under the wheel into a position against stop 15b so as to secure the wheel in its supporting position. The adjustable struts 28, 29 also serve as supports. Platform 38 (Fig. 2). The platform has rollers 40 which run over the front flanges of the mast 2 and also rollers 41 which run underneath these flanges. It is operated by cable 50 which is secured at one end on the mast, passes round pulley 53 on the platform, then round pulleys 52, 51 at the top of the mast and is secured at the other end to winch drum 45. Winch drum 45 (Figs. 2, 5). The drum is driven from power unit 46 through clutch 66 and gears 69, 70, 71, 72, the latter being fixed on the drum. It is hand controlled from rope 49 which passes over pulleys 84, 81 (on pivoted bar 82), and is attached to lever 48. The latter is pivoted at 59a and presses against sliding rod 62 and pivots on sliding rod 77 so that when the rope is pulled, brake 75 is released from clutch member 63 and the latter is clutched to the motor which then raises the platform. Auxiliary hand winch 55 is for use when the motor breaks down. Top of mast. (Fig. 7). Adjustable head 80 is detachably slidden on to the top of the mast to form an extension thereof. It carries the two wheels 51, 52, a sleeve 101 for the rope 49, pin 83 on which arm 82 swings, and safety arm 79. The latter has an eye 78 to which the rope 49 is secured so that when the platform rises to the top of the mast it tips one end of this safety arm and so slackens the rope 49 which is attached to the other end and this stops the motor. A bracket 88 (Fig. 1) may be attached to the mast and by means of clip 91 it may support or be supported by scaffolding. The detachable head may be of specified length so as to increase the height of the mast by the'desired amount.