Abstract: A shingle coating asphalt composition is provided that is produced from a paving grade asphalt. The asphalt composition comprises a paving-grade asphalt that has been modified with one or more polymer additives; and a secondary additive comprising one or more of a viscosity reducing agent, a wax, a salt of a fatty acid ester, and an amide of a fatty acid. The shingle coating asphalt coating composition is used to make a shingle. The shingle includes a substrate, the asphalt, and roofing granules.

Abstract: A drill bit includes a bit head and a rotating bit cone. A sealing system for the drill bit includes a seal gland and a seal retained within the seal gland. The seal gland is defined by a radial cone surface, a head sealing surface and an opposed cone sealing surface. At least one of the head sealing surface and opposed cone sealing surface is not cylindrical (i.e., the surface is conical and not parallel to an axis of rotation for the cone). Additionally, the radial cone surface may be conical (i.e., the surface does not extend perpendicular to the axis of rotation of the cone). The seal is radially compressed between the head sealing surface and the opposed cone sealing surface. The use of one or more conical surfaces in the gland is provided to bias the compressed seal into a preferred dynamic sealing zone.