| 摘要 |
<p>Ends of plastics pipes are thickened in mfr. of sleeve couplings, with the use of devices comprising >=1 outer tool of configuration representing the outer contour of the intended sleeve; a mandrel which fits into the plastics pipe end and can be moved there axially; and a compression flange outside the mandrel which also moves coaxially, operating between mandrel and tool. The process includes (a) positioning the heated pipe end inside the tool and clamping it there; (b) simultaneously displacing the mandrel inside the pipe and the flange outside the mandrel; (c) stopping advance of mandrel as flange hits end of pipe, with distance from final position corresp. to shape of intended sleeve; (d) advancing flange to compress pipe end; (e) moving mandrel and flange into predetermined final positions thereby compressing (and thickening) pipe end. Used in the installation, e.g., of plastics water pipelines which withstand stresses arising from water pressure, and ensure leak-free operation. The resulting ratio of wall thickness: dia. conforms with official regulations.</p> |
