| 摘要 |
<p>1,111,623. Extruding double-walled pipes. FETOK G.m.b.H. 17 Feb., 1966 [15 April 1965], No. 7108/66. Heading B5A. A double-walled ceramic pipe, Fig. 8 (not shown), wherein the walls are connected by a plurality of bridges which run the length of the pipe, is made by extruding the ceramic material through an annular array of orifices in a die plate 21 to enter inserts 27, from which the material moves laterally through apertures 28 and is then constrained to move axially between annular walls 23, 24 of die plate 21 and plates 26, fixed to the downstream ends of inserts 27, and between plates 26 themselves. The form of the bridging between the pipe walls is dependent on the number and shape of plates 26 which may be, for example, triangular, Fig. 3 (not shown), or circular, Fig. 6 (not shown).</p> |
