| 摘要 |
PURPOSE:To prevent increase of the force conducted to the basis via a support table, by furnishing a means to change spring constant, and controlling so that eventual change in the vibration frequency of vessel does not increase the amplitude of the vessel. CONSTITUTION:A control device 26 senses amplitude of a cylinder 17, i.e. of a vessel 1, by the use of a signal given by a location sensor 25. The control device 26 actuates a compressor 22 and sends the gasious elastic fluid from vessel 20 into a space 16 via a four-way valve, a compressor 22, a flexible tube 23, and a throttle 24. Now the gasious elastic fluid moves to a space 15 through a gas between said cylinder 17 and a weight piston 18 to cause the means pressure of the two spaces 16, 15 to increase. Decrease of the amplitude of cylinder 17 in such a way should actuate the compressor 22. If the amplitude of cylinder 17 begins to increase, by contrast, the compressor 22 shall be stopped. Thereby the amplitude of the vessel 1 is controlled so as not to increase even through the vibration frequency of the vessel 1 varies. |
