Formwork for box shaped concrete shells - has main triangular interior mould halves and triangular corner pieces released by cylinders

摘要

Prefabricated concrete shells in the shape of open topped boxes are made in formwork with four vertical surfaces enclosing the four sides, with a split mould inside to support the top. Shells are made without projections on the inside surfaces. Each mould has a vertical triangular column (43, 44) in each corner, and two large triangular portions (45, 46) which abut one another along the diagonal line (58) between the vertical columns. To remove the mould, the two columns are swung inwards and downwards by cylinders attached to each at an angle to the horizontal at different heights. Similarly, the main triangular portions which are secured by interlocking tubes, are released and swung out of engagement.