Elastomeric disc for use on a pipeline pig

Claim 1

An elastomeric disc for use on a pipeline pig of the type having a longitudinal body supported centrally within a pipeline for movement by fluid flow therethrough, the disc comprising: a unitary elastomeric member having an inner portion of selected thickness and having a center; an outer peripheral surface normally concentric with said center; means for attachment of said inner portion to a pipeline pig body whereby the disc is supportable in a plane perpendicular the pipeline axis; an integrally formed circumferential outer portion integrally extending from said inner portion to said outer peripheral surface and having said peripheral surface thereon, the outer portion having opposed side surfaces, the outer portion being of increased thickness in relation to the spacing thereof from the disc center, the outer peripheral surface being defined by first and second intersecting frustraconical surfaces such that one of said frustraconical surfaces is parallel to the inner wall of a pipeline through which the disc is moved in a first direction and the other of said frustraconical surfaces is parallel to the inner wall of a pipeline when the disc is moved in a second direction, the first frustraconical surface being substantially perpendicular to said first side surface when the disc is moved in one direction within a pipeline and the second frustraconical surface being substantially perpendicular to said second side surface when the disc is moved in the opposite direction within a pipeline, the disc outer portion thereby providing support to said frustraconical surfaces, the intersection of said side surfaces with said frustraconical surfaces providing opposed wiping leading edges depending upon the direction of the travel of the disc in a pipeline.