| 摘要 |
865,141. Stairs; building blocks. COSTAIN Ltd., RICHARD. Nov. 18, 1957 [Nov. 16, 1956], No. 35152/56. Classes 20(4) and 87(1) In a method of constructing staircases of concrete in which the treads and risers are precast as single units each comprising one or more steps, the units are located in position in situ and fluid concrete or other construction material is poured to unite the units together to form a staircase. As shown the pre-cast - steps 6 are triangular in cross-section, and are hollow or provided with frogs 6a, and reinforced by rods 7a or pre-stressed, the projecting ends of the rods being cut off after formation of the flight of stairs or utilised for the attachment of handrails. In the assembly of the staircase between floors 1, 2, shuttering 3, 5 together with reinforcing bars 4 for a supporting soffit 10 are placed in position, the steps being disposed to bear on the upper edges of the side shuttering 5; preferably, the steps are separated by adjusting wedges 7. Concrete is poured into the space 8, the shuttering 3 being vibrated. Wire members 12 are cast in each step unit to provide a tie between the units and the soffit. The top step 11 of the flight may be cast with the top landings 9, and the soffit may be a pre-formed base comprising prestressed slabs. The exposed faces of the steps may be given a terrazo surface. |
