To provide a staircase structure, capable of efficiently assembling a closed string-type staircase with a small amount of time and labor and reducing the processing cost by limiting finishing only to the upper surface of treads.
This staircase is constructed of a pair of right and left strings 1, treads 2, riser plates 3 and a connector 4 for connecting the tread and the riser plate. The connector 4 has a first groove 11 opened backward and a second groove 12 provided no the lower side of the first groove 11 and opened downward. The front 2a of the tread 2 is inserted in the first groove 11 and fixed, and the connector 4 is fixed to the tread 2. The riser plate 3 is fixed to a vertical receiving part 7 of the string 1, and the tread 2 is placed on a horizontal receiving part 8 with the second groove 12 fitted to the upper part 3a thereof. After that, both ends of the tread 2 are fixed to the string with small screws 24.
SHINKAWA KATSUYUKI
INUI TORU
OGAWA KANAKO
