| 摘要 |
<p>1537093 Valves WIBAU WESTDEUTSCHE INDUSTRIE - UND STRABENBAU - MASCHINEN GmbH 19 Feb 1976 [14 June 1975 12 Dec 1975] 06634/76 Heading F2V A valve in or for a double-piston pump for pumping concrete, comprises a slide 11, Figs. 1 and 3, having at least three longitudinallyextending plane faces defining, as seen in crosssection, at least one included angle of less than 90 degrees. Instead of the triangular form shown, the cross-section of the slide may be of trapezoidal form, Fig. 4 (not shown). The complementary casing has two ports in wall 1 for communication with the pump cylinders 12, two ports in wall 2 for communication with delivery conduit 15 and two ports in wall 3 for communication with a vessel 22 containing the concrete. The slide is provided with two ducts 18 near its ends and an intermediate duct 20, whereby in either end position of the slide one of the pump cylinders 12 is communicated with the vessel 22 and the other cylinder 12 is communicated with the conduit 15. Sealing rings 24 are provided around the ends of the ducts 18, 20. Casing walls 1, 2, 3 are coated with hard silicone rubber.</p> |
