| 摘要 |
PURPOSE:To adjust quickly easily the depth of water without reducing a pool area to be used by providing liftably underwater steps separately from bottom surface of a pool or bath tub to adjust at will the depth of water. CONSTITUTION:Underwater steps are provided vertically movably on the whole or a part of the bottom of a pool or bath tub. The respective underwater steps 3 are lifted to a predetermined height by controllably opening and closing a solenoid valve 16 for a hydraulic cylinder to operate the cylinder. Also, pressurized water is sent to any of ports of the hydraulic cylinders to forcibly open a pair of connecting arms, contract a lift mechanism 8 and lower the underwater step 3. The respective underwater steps 3 are individually lifted and lowered so that the area on only one course or only half area on two courses can be lifted. A hand rail with a net is brought down to be located in the side end of the underwater step 3 when not in use. |
