Patent GB-874272-A (GB)
Title: Improvements relating to apparatus for shifting stage scenery
Inventor: MORTON DAVID CHARLES
IPC: A63J1/02
Filed: 1958-06-04
Abstract: 874,272. Stage scenery shifting apparatus. PACKMAN MACHINERY Ltd., and BRITISH BROADCASTING CORPORATION. Sept. 3, 1959 [June 4, 1958], No. 17868/59. Class 132(1). [Also in Group XXV]  Scenery shifting apparatus, which is mounted on castors, can be releasably secured to the scenery at intervals along its length and includes a number of jacks which can be raised and lowered simultaneously to raise and lower the scenery. As shown, a zig-zag framework 1 made up of tubular arms 2 has a castor 3 at each angle. The ends of each arm 2 carry upper and lower plates 6, 7 which with plates 6a, 7a of the adjacent plate turn respectively round sleeves 8, 9. Each castor 3 is rotatably mounted on a plate 10 rigidly secured to a plate 7 or 7a. A support 21 carrying two sprocket wheels 22, 23 is secured at each angle.. to a spindle 15 whose base engages a ball bearing 16 in the plate 10 and is held vertical by sleeves 17, 18 which engage flanges 29, 30 on sleeves 8, 9, the latter flanges engaging plates 6, 7 to prevent vertical movement of spindle 15. Sprocket wheels 23, Fig. 4, are connected by a continuous chain 35 guided by wheels 36 and sprocket wheel 22 is connected by a chain 37 guided by wheels 38 to a wheel 22a at the end of the adjacent arm 2 so that the whole framework is connected up and movement of one spindle by a handwheel 40 geared thereto moves the whole framework. A tapped block 40a threaded on the upper end of each spindle 15 5 carries diametrically opposite grooved pins 41a and if the block 40a is prevented from rotating with spindle 15 as it rotates block 40a rises or falls so operating like a jack. Either pin 41a of each block may be secured in a socket 44 and the sockets may be fixed rigidly to the back of the scenery to be moved. Otherwise the sockets 44 may each be fixed to the back of a vertical plate 45a rigid with a plate 46 faced with felt to engage the front of the scenery 47 and a platform 48 to engage a cutaway 49 in scenery 47, a plate 50 on the scenery extending through a slot 51 in the plate 46 and having a slot which is engaged by a bolt 53 on the plate 46. In use, the apparatus is pulled out and the plates are engaged with portions 49 and secured. Wheel 40 is then rotated and the scenery is lifted,-the apparatus being sufficiently heavy, counter weighted if necessary, to prevent it from toppling over. Arms 2 may be secured relatively to one another by strips 55 pivoted at one end 56 to one arm 2 and having a series of holes 57 through which a pin 58 may be passed which also passes through a slot 59 in a plate 60 secured to the other arm 2. Alternatively, pivoted bars 60 may be secured to the framework by discs 65, 68 held separated by spacers and secured to the arm by braces 66 and nuts 67. The edges of discs 65, 68 are clamped on bar 60 by turning a screw .70. The scenery . may be supported additionally by struts releasably connected to the scenery and to adjacent spindles 15. An adaptor may be provided for use 'in attaching the apparatus to hinged flats near the hinge which includes a socket to receive one of the pins 41a. Alternatively hydraulic jacks may be used. In further apparatus, Fig. 15 (not shown) a series of hydraulic jacks are provided all connected to a single control. Fig. 16 (not, shown) illustrates an arrangement of mechanical jacks operated simultaneously by a system of connecting rods.