GB1339826A - Apparatus for moving scenery - Google Patents

Abstract

1339826 Scenery moving apparatus MOLE RICHARDSON (STAGE & STUDIO ENG) Ltd 7 July 1972 [8 July 1971] 32102/71 Heading A6M Scenery raising and lowering apparatus comprises a vertical hydraulic cylinder 1 having a piston defining upper and lower spacer therein, a piston rod 2 extending upwards from the cylinder and operatively connected to a pulley system 5-11 having a velocity ratio of 4 and being adapted to raise or lower scenery 13, the hydraulic cylinder being operated by pressure fluid supplied to the upper space thereof. The cylinder is supported by a single pivot only and the pulley system is supported by a bracket 7 secured to wall 3. The supply of fluid to and drain from the cylinder is controlled by a spool type directional valve (28) in a conventional hydraulic system - Fig. 2 (not shown). The valve is operated from a control box 32 having an operating lever 34 connected by crank 35 to valve linkage 23, (22). In the control box, Figs. 3 and 5, the lever 34 is connected via a sleeve 46 to an axially moveable rod 47, the sleeve 46 being adjustable as to its position on rod 47. The rod 47 has a centreing spring 49 and carries adjustable stops 54, 57 and the position of the sleeve 46 can be used to set the speed of raising or lowering the scenery by positioning the lever 34 and thus determining the amount the control valve (28) is opened. Also in the control box 32 is a drum 59 rotatable by the wire 29 wrapped therearound the ends of the wire being connected via pulleys 31 (Fig. 1) to a member 36 connected to the piston rod 2. Thus movement up and down of scenery 13 rotates the drum 59 which rotates screw 37. The latter carries a non-rotatable nut 38 which thus moves up and down according to the position of the scenery and this can be indicated on a suitable scale by pointer 41. The screw also drives a 'fine' position indicator 43. Engagement of the nut with either of stops 53, 54 moves rod 47 axially to move the lever 34 to its central position to centralise the control valve (28) and thus cease the motion of the piston and thence the scenery 13.