| 摘要 |
The rate of movement of a balanced float controlled valve, between either open and closed positions, is not subject in either direction to the rate of movement of the float. The dimensioning of the linkage is designed to allow the valve to stay in the partially self-locked state when the valve assembly is in one end position and resistant to forces exerted the valve shaft towards the second end position but is easily released by a balance lever when torque is applied to the balance lever by the weight of the float. The balance float (10) controlled valve assembly has at least one valve (2), a tank (4) and at least one balanced float connected by a link to the free end of a balance lever (31). The valve has a closure with a valve shaft (25) guided to slide between open and closed positions. The valve assembly also has a link mechanism (3), arranged between the balance lever and the valve shaft, designed to stay in an approximately self-locked condition when the valve shaft stays in one end position. The self-lock state of the mechanism is resistant to forces biasing the valve shaft towards its second end position to close the flow through the valve but is easily and rapidly released by the balance lever when a torque is exerted onto the balance lever by the weight of the balance float. |
