| 摘要 |
1,158,793. Pipeline pigs. T. D. WILLIAMSON Inc. 4 Sept., 1967 [26 June, 1967], No. 40370/67. Heading F2N. A cup for use on a pipeline pig 10 comprises a unitary annular structure which is made of polyurethane, of a durometer of from 65 to 85, and has (a) a body portion 13 for fastening, e.g. by engaging a radially extending annular surface, to the pig body 10, (b) a lip portion 15 for sealing and slidingly engaging an inner wall of a pipeline, and (c) a web portion 17 which integrally joins the body and lip portions 13, 15 and which is shaped so as to position substantially all of said lip portion 15 to the rear of the juncture 18 of the web portion 17 with the body portion 13 when the web portion is in the relaxed state, the web portion having a flexing section intermediate said body and lip portions. As shown the pig 10 consists of a hollow cylindrical section 11 which has brushes 12 and a radial flange 10d, to which cylindrical portions 13a of the body 13 are attached by bolts 14, the length of the web 17 being chosen to give the required radial flexure. The thickness "X" of the web 17 should be sufficient to support the pig section 11 and to prevent reversal of the lip 15, the latter being thick enough so that the pressure differential across the cup does not press the lip 15 into excessive frictional contact with the pipe 16. Optimum results are stated to be achieved when the thickness "T" at the juncture 18 is approximately one quarter of the distance "F" between the juncture 18 and inner wall of the pipeline 16 and, when the minimum thickness "X" is about half of the thickness "T". |
