GB966833A - Improvements in or relating to annular sealing elements - Google Patents

Abstract

966,833. Seals; pipe joints; valves. ISTAG A.G. SUHR/A.G. April 1, 1963, No. 12768/63. Headings F2B, F2G and F2V. A sealing ring, Fig. 2, comprises an annular packing 1 formed of a sealing strip of resilientlybonded, non-combustible fibres and radially compressed between metallic sheath ring members 2, 3 whereby only the two end faces of the packing provide sealing surfaces. As shown, one of the sealing surfaces is spherically concave. The fibres may be asbestos, glass or mineral wool and may be bonded by synthetic or natural rubber or by a resilient plastic material. They may be reinforced by abrasion-resistant inserts 5 such as nickel or aluminium foil or mesh. The sheath members 2, 3 may be in the form of single rings or one or, as shown, both of them may be formed of coiled metal bands which may be corrugated. The members may be provided with screw-threads as fastening means. In a method of making the sealing ring, the packing 1 prepared from a wound sealing strip is pressed into the space between the sheath members 2, 3. In another method, the sheath member 3 in the form of a steel tape is first wound on a mandrel, the individual windings being welded or cemented together. A sealing strip is then secured to the member 3 or to the mandrel and wound on to the member 3 by means of a roller exerting pressure radially inwardly, whereafter the sheath ring 2 is wound on to the sealing strip. A nickel wire mesh strip is fitted between the windings of the sealing strip. The spherical concave end surface of the packing 1 is produced by turning or grinding or by moulding with a ball-shaped member in the presence of heat. The plane end face of the packing 1 may protrude from the plane end faces of the sheath members 2, 3. The end face of the member 3 adjacent the spherical end face of the packing is bevelled inwardly. Fig. 4 shows a ball-and-socket type pipe joint in which the sealing ring 20 is fixed in a recess in the socket 18 and has its spherical surface co-operating with the movable ball member 17 which is urged towards the socket by a sleeve 21 screwed thereon. In another embodiment, Fig. 3, two sealing rings 1a are used to seal a ball valve 6 to the housing 7 of a tap and to a flanged conduit 8. The valve is rotatable by a pin 11 secured to a handle 8<SP>1</SP> and sealed to the housing by a stuffing-box 10, 12.