| 摘要 |
<p>PURPOSE:To improve both of wear-resisting and sealing performance of a tube used in a pinch valve for conveying slurry, by constituting the tube from an outer and an inner, two layers made of different rubber-like resilient materials respectively having particular hardnesses. CONSTITUTION:A tube 1 is covered with a pair of upper and lower housing members 2. The inner layer 1c of the tube 1, kept in contact with a fluid to be conveyed, is made of a rubber-like material having a hardness of 40-50 deg., whereas the outer layer 1d of the tube 1, not brought into contact with the fluid, is made of a rubber-like resilient material having a hardness of 60-70 deg.. Further, a pair of compression members 3 are provided in a cam body 4 such that their ribs 3b are held in engagement with stepped helical surfaces 4a inside the cam body 4 and they are moved vertically by turning the cam body 4. The tube 1 is opened and closed by the movement of the compression members 3.</p> |
