Patent ID: 7568676

Claim:
A form panel for placing concrete made of plastic comprising: a hollow sheathing section, one side of which forms a concrete placing surface, hollow side panel sections bent out at right angles from both ends of said sheathing section on a side of said sheathing section opposite to said concrete placing surface, two hollow projecting sections, which extend in a vertical direction, provided on ends of an outside surface of at least one of said hollow side panel sections in a protruding manner toward the outside of said hollow side panel sections, each of said two hollow projecting sections having a length side surface and two width side surfaces, wherein one of said width side surfaces of one of said two hollow projecting sections is coplanar with said concrete placing surface of said sheathing section, a first diagonal rib which is diagonal relative to said concrete placing surface formed within said one of said two hollow projecting sections, wherein one of said two width side surfaces of said one of said two hollow projecting sections provided with said first diagonal rib is coplanar with said concrete placing surface of said sheathing section, and in contact with a corner, which is located on a distal end of said one of said two hollow projecting sections on said concrete placing surface of said sheathing section, and a second diagonal rib which is diagonal relative to said concrete placing surface formed within the other of said two hollow projecting sections, wherein one of the two width side surfaces of said the other of said two hollow projecting sections provided with said second diagonal rib is provided at a distal end surface of said hollow side and section, which is on the opposite side of the hollow sheathing section, and said second diagonal rib is in contact with a corner, which is located on a distal end of said the other of two hollow projecting sections on said distal end surface of said hollow side panel section, which is on the opposite side of the hollow sheathing section.