GB861910A - Improvements relating to the casting of reinforced concrete beams - Google Patents

Abstract

861,910. Casting reinforced concrete beams. LEES Ltd., R., and OAKDEN, R. R. Sept. 19, 1957 [Sept. 25, 1956], No. 29251/56. Class 87(2). A machine for the production of long runs of reinforced concrete beams comprises means for controlling in alternation the operation of feeding and of consolidating the conconcrete by vibration and the movement of the mould. When a switch 11 is operated, (1) a paddle at the outlet of a large hopper, not shown, makes a quarter turn to deliver a measured quantity of concrete into a hopper 3 which deposits it on the floor over a suitable area. (2) A frame 1, carried on a gantry (not shown) advances lengthwise from a length of beam just previously cast on the floor, from the Fig. 1 to the Fig. 2 position (3) shafts carrying eccentric weights are rotated, in tubes 7, 10, the tubes thus becoming vibratory cores within the mould sides 9, neither moving with the frame 1. The movement of the frame, and the vibration, are stopped at the Fig. 2 position by a limit switch 17; also a switch 19 causes compressed air to be admitted to two upper cylinders 4 which are mounted on a carriage which carries the hopper 3 and is slidable on horizontal rods 2 which are components of the frame 1. Operation of the pistons in the cylinders 4 advances a second carriage 20, also slidable on the rods 2, to which the tubes 7 are attached, which are therefore withdrawn from the previous beam length, leaving holes, of which the walls are still supported by inflated tubular rubber extensions. At the end of its travel a projection 18 from the carriage 20 operates a switch 22 which causes compressed air to be admitted to two lower cylinders 5, the pistons of which move a third carriage 21 to which the tubes 10 and mould sides 9 are attached. If the sides 9 are vibrated they have rubber extensions to support the length of beam just cast. This is also acted on by a transversely operating screeding board 25 carried by the frame 1. At the end of the travel of the carriage 21 a projection 23 therefrom operates a switch 24 which causes compressed air to be admitted to the other sides of the pistons in the cylinders 4 and 5 so that the carriage comprising the hopper 3 and the cylinders is advanced, a projection 12 therefrom operating the switch 11 and recommencing the cycle. For pre-stressed concrete, wires are tensioned along the run of the beams. In the arrangement shown, Fig. 5, three beams are cast side by side. The beams are sub-divided after setting by a diamond abrasive cutting wheel.