| 摘要 |
PROBLEM TO BE SOLVED: To provide a balance chair that can reduce physical burden on a person performing work with his arm kept raised. SOLUTION: A joint type holding arm 2 comprises a first arm 3 and a second arm 5. The first arm 3 is made roughly cylindrical as a whole, a first ball body part fixed on the body 1 of a chair is arranged free to rotate in the course of a part biased to a base end part thereof and a second ball body part having a base end part of the second arm 5 mounted at the tip part thereof is arranged free to rotate. A lock shaft is movably mounted longitudinally through a fine interval between the first ball body part and the second ball body part along the length thereof. A piston is provided at the base end part to allow constantly pressing of the first ball body part to the tip side by a spring means while moving of the first ball body part to the base end side against the spring means by a hydraulic means 14 or an air pressure means. The second arm 5 is provided with a support part 20 at the tip part thereof to support the arm of a sitting person. |
