GB868161A - Improvements in or relating to sealing means for an opening - Google Patents

Abstract

868,161. Closures for resisting fluid pressure. BIRFIELD ENGINEERING Ltd. Feb. 16, 1960 [Feb. 16, 1959], No. 5240/59. Class 123(1) [Also in Group XXVIII] Sealing means for an opening, e.g. the upper end of a standpipe, comprises a cup-shaped, flexible sealing member 9 the side wall 9a of which is adapted to seal against the wall of the opening, pressure means 12, abutment means 1 adapted to be fixed relatively to the opening, and wedge means 6 surrounded by the pressure means. Movement of the wedge means outwardly of the opening urges the pressure means laterally outwards to press the member 9 into sealing engagement with the wall of the opening, movement of the pressure means with the wedge means being limited by the abutment means. Positive pressure within the opening may act to produce or assist the sealing engagement. As shown, the member 9 is clamped to the annular wedge member 6 which is carried on a hollow stem 5, and the conical wedging surface 10 of the member 6 is held in contact with the inclined inner surfaces of an annular ring of segmental pressure shoes by an annular spring 13 seating in a groove 15 formed in the shoes. The spring has an internal wire 14 which holds the shoes together in the event of breakage of the spring, and the shoes are provided with spaced lands 20 the innermost land 22 of which projects slightly in a lateral direction. In sealing the opening the closure plug is locked in the opening by cams 3 engaging in a recess 4 in the pipe 2 and the stem 5 is moved outwardly so that the shoes 12 engage the abutment ring 1, further movement of the stem causing a wedging reaction between the ring and shoes to urge the latter outwardly so that the land 22 of the shoes press a localised continuous area of the wall 9a of the sealing member into sealing engagement with the wall of the opening; as wedging action continues the remaining lands 20 in turn press against the wall 9a so that the sealing area progressively increases. The member 9 is ridged at 23 to facilitate flexing thereof. The pressure ring may be continuous and sufficiently flexible to undergo the requisite expansion and is preferably of split form, or a number of split rings may be arranged side-byside in an axial sense; the ring or rings may be mounted on a split ring carrier expanded by the wedge means.