| 摘要 |
<p>A method and apparatus for making concrete slabs to be used in the construction of walls or floors in buildings. The slabs can be made of desired thickness as, for example, from 8 inches to 24 inches and of lengths which also are optional as, for example, from 8 feet to 12 feet. Assemblies of core members are disposed on opposite sides of a cavity, to be moved back and forth with respect to the cavity for molding recesses in opposite edges of a slab and to be retracted therefrom when the concrete has set to the desired extent. The mold assemblies each comprises a plurality of core members spaced longitudinally of the cavity and when moved to inner positions will leave an open space therebetween for molding a central web in the slab, with transverse webs extending out to the lateral edges of the slab. Additional core members may be disposed between the main core members. The small core members will form longitudinal openings through the slab. The release of the mold assemblies is in two steps. Initially, a wedging action or other means moves the core members just sufficient to break the seal with the formed slab in the recess thereof and thereafter hydraulic jacks are used to retract the mold assemblies.</p> |
