| 摘要 |
PROBLEM TO BE SOLVED: To provide a temperature compensation type spring balance capable of securing an adjustment amount of the moment of inertia of a spring balance without drastically changing the weight and the size of the spring balance.SOLUTION: The temperature compensation type spring balance according to the present invention has a balance staff 2 rotating around a shaft, a balance wheel 12 which is arranged around the balance staff, and a weight portion 14 attached to the balance wheel, and has: an arm 4 having a first arm portion 6, which includes a first base portion 22 which is fixed to the balance staff, and a first free end portion 26 which displaces in a radial direction about the balance staff with temperature changes, a second arm portion 8 including a second base portion 32 fixed to the balance wheel and a second free end portion 36 which displaces in a radial direction with temperature change; and an intermediate member 10 including a first contact surface 10a which comes in contact with the first arm portion and crosses an expansion direction of the arm and a second contact surface 10b which comes in contact with the second arm portion, crosses the expansion direction of the arm, and is formed inside the radial direction from the first contact surface, and has thermal expansion coefficient smaller than the thermal expansion coefficient of the arm. |
