Manufacture of light-weight concrete building units

1,096,854. Cutting concrete blocks. DUROX INTERNATIONAL S.A. Jan. 18, 1965 [Feb. 20, 1964 (2)], No. 2170/65. Heading B5A. A concrete block (in plastic condition) is cut into building units by first cutting the block into intermediate blocks by means of vertical cutting wires extending through parallel slots in the support on which the block rests, separating the intermediate blocks from each other and cutting each intermediate block separately into building units by means of horizontal wires moved vertically therethrough. Concrete mix is poured into a frame 3 supported on bars 4 resting on longitudinal projections of a base 2. When the mix has set suffiiently the frame is removed and vertical cutting wires 7 mounted in a frame 6 drawn therethrough to slice off the sides and provide three intermediate blocks. Each block, supported on a bar 4, is moved from the base and horizontal wires 9 supported on a frame 8 drawn vertically therethrough after which the top and bottom surfaces of the block are cut off by wires 12 drawn horizontally therethrough. In an alternative arrangement, to avoid rough edges, a frame having two vertical and two horizontal cutting wires is first drawn through the intermediate block (Fig. 7, not shown) after which the block is cut into building units by moving horizontal wires therethrough to penetrate into the bottom layer 27.