Patent GB-988400-A (GB)
Title: Improvements in or relating to formwork, particularly for casting towers
IPC: E04G11/28
Filed: 1962-05-16
Abstract: 988,400. Shuttering for casting concrete towers. J. BOSSNER. May 16, 1962, No. 18932/62. Heading E1S. The walls of concrete towers are cast in shuttering 130, 131, Fig. 1, the peripheral extent of which, can be varied, the inner shuttering 131 or both the inner shuttering 231, Fig. 3, and the outer shuttering 230 being supported on a tube or a cylindrical frame 115 surrounding and slidable on a central vertical tube or lattice mast 111 supported on the already cast walls 114 of the tower. In Fig. 1 the inner shuttering 131 only, is mounted on the frame 115 by means of arms 127, 120 adjustable in length to allow variation of the peripheral extent and angle of the shuttering and the outer shuttering 130 is suspended from radial arms 119 on the top of the mast 111 and connected to the inner shuttering by spacers 128. When a section has been cast the frame 115 and shuttering 130 are raised for the next pour by winches 117, 138 respectively connected by ropes to the arms 119. When the frame 115 has reached the top of the mast 111 the arms 112 of adjustable length by which the mast is mounted on the cast walls 114 are disconnected and the frame is raised by winches 117a and ropes 118a on the frame 115 which is still fixed to the tower walls by the shuttering, for casting a further series of sections. Scaffolding 135, 136 and 137 is provided on the frame 115 and the outer shuttering and a staging for ladders &c. 140 is built up under the apparatus. In Fig. 3 the inner and outer shuttering 231, 230 are suspended by rollers from rails 222 on arms on the top of the sliding frame 215. The arms 219 on top of the mast carry a roof 236 and frames 225 secured at 226 to the walls 214, for guiding rollers 237 on the end of the rails 222 and for carrying staging. In a further modification, Fig. 4, the inner shuttering is mounted on tubes 23 and the outer shuttering is mounted on frames each comprising vertical tubes 24, 25 connected by horizontal tubes 26 and each vertical tube is suspended from rollers on the rail 22 by adjustable connections 25<SP>11</SP> to allow the angle of the frames to be adjusted. The shuttering is made circumferentially in six sections of 60 degrees each and is a third of the height of the frames 23-25 and each section is slidable on a vertical rail 44, Fig. 7, mounted on the frames 23-25. The shuttering is raised on the frames by winches 32, 33 for casting three sections of wall one above the other in sequence. Then the shuttering with the sliding frame 15 is raised on the mast 11 to a new casting position. During casting, bolts 29, Fig. 7, pass through tubes 26 into a screw threaded end of a spacer 28 and other bolts 29 pass through sleeves 27b into the other end of the spacer. The sleeves 27b are pivoted on the arms 27a supporting the inner shuttering. To allow for variations in diameter or cross-sectional size of the tower the gaps between the edges of the shuttering sections are covered by plates 41, Fig. 6 welded to channels 41a mounted by tubes 35a on the frames 23-25. To resist the pressure of the concrete, wing screws 42 screwed into spacers 28 bear on bars 38 bearing on the outside of the shuttering 34. Also clamps 37 straddling the bar 38 and one of which engages the edge of each shuttering section have ends 40 offset towards one another for the outer shuttering and away from one another for the inner shuttering to resist the circumferential tension and compression of the liquid concrete.