GB659448A - Cores for use in casting hollow concrete beams or columns - Google Patents

Abstract

659,448. Collapsable cores for moulding hollow concrete beams &c. DOW-MAC (PRODUCTS), Ltd. March 30, 1949, No. 8696. [Class 87 (ii)] A core comprises two side members 10 which engage top and bottom members 11, 12 at surfaces 13 which taper outwardly. To members 11, 12 are secured stiffening members 29, 30 to which are fixed wedges 18. Other wedges 17 secured to a central rod 15 co-operate with wedges 18 to hold the core in its expanded condition. Pins 31 hold the wedges in position. The assembled core may be held together by winding around it short lengths of soft iron wire, which are left embedded in the concrete, and is supported at its ends by mould end-plates and at its middle by ties secured to supports extending across the top of the mould. Each side member 10 embodies a plate 19 into which are screwed push-rods 21 passing through the mould 14, ferrules 36 shielding them from the concrete. A push-rod 24 for the top 11 is carried by a crosspiece 33 held in position by bolts 34 secured to the mould by bolts 35, and a pull-rod 27 for the bottom 12 also is carried by a cross-piece secured to the mould by bolts. To collapse the core, the pins 31 are removed and the wedges 17 moved to the left, Fig. 2, by turning a nut 16 on rod 15, this nut bearing against a bridge 20, then the sides, top and bottom are urged inwardly by turning the nuts 22, 25, 28 on the rods 21, 24, 27. The ferrules 36, 37, 38 surrounding the rods are left embedded in the concrete. An additional ferrule surrounds the upper end of rod 24, and this is recovered and used again. The plates 26, 32 to which the rods 24, 27 are secured serve as dowels to locate an adjacent section of the core, which may be in two halves each withdrawable from its adjacent end; alternatively, the. core may be unitary.