| 摘要 |
PROBLEM TO BE SOLVED: To solve problems with wooden bathtubs that water leaks from big gaps between the adjacent wooden boards caused by expanding or shrinking of the boards depending on wet or dry conditions of boards and that the wooden bathtubs are inferior in durability because of rotten boards caused by water staying between the wooden boards. SOLUTION: A wooden bathtub is made of plural wooden, flat boards. A side wall of the bathtub is formed by piling up the wooden boards vertically while keeping a surface with the wide width of each wooden board horizontal. An inner surface of a bathtub is made by surfaces with the narrow width of the wooden boards, which are piled up. The wooden, flat boards which are piled up vertically are shifted in a horizontal direction alternately. |
