To simplify connection at a specified angle by holding the side faces of both columnar bodies by edge contact parts to eliminate dislocation in a side face direction, and fitting guide protrusions into grooves of the columnar bodies to determine the butt angle of the columnar bodies.

A fixture 11 with grooves 11a, 11b vertically formed at both side faces of the center of a bar of laterally long rectangular shape is fixed to a plate 10 by screws. When the side faces of a plate support leg 2 are made to butt the fixture 11 to put connecting fittings 5, 6 thereto from both sides, edge contact parts hold the fixture 11 and the side faces of the support leg 2 to eliminate dislocation in a side face direction, and the lower parts of guide protrusions are fitted into the grooves 11a, 11b of the fixture 11, while the upper parts are fitted into grooves 2a, 2b of the support leg 2 and fixed by screws 5f, 5g, 6f to determine the butt position and angle. A sign plate support frame 3 is formed as a U-shape frame body by combining the same material as the support leg 2, fitting L-shape fittings 12 into the grooves 2a, 2b and fixing them by screws 13. This sign plate support frame 3 is fitted to the support leg 2 by screws 15, 16. Columnar bodies can therefore be easily connected to each other at a specified angle.