Abstract: The present invention relates to elastic nonwoven materials comprising an elastic layer formed from a polymer blend comprising a propylene-based polymer and a minor amount of an ethylene-based polymer. The propylene-based polymer may comprise from about 75 to about 95 wt % propylene and from about 5 to about 25 wt % ethylene and/or a C4-C12 ?-olefin, and may have a triad tacticity greater than about 90% and a heat of fusion less than about 75 J/g. The ethylene-based polymer may comprise from about 65 to about 100 wt % ethylene and from 0 to about 35 wt % of one or more C3-C12 ?-olefins.

Abstract: The invention concerns a certain class of polymers, their production into films and applications for their use. These polymers have unique properties which make them particularly well suited for use in polymeric films. These films are very useful in applications requiring heat sealability, particularly those applications containing an ionomer film.It has been discovered that polymers derived from metallocene catalyst systems surprisingly heat seal extremely well, as compared to polymer produced by conventional Ziegler-Natta catalysts, to a class of polymers known as ionomers.

Abstract: A hybrid rock bit is disclosed wherein a pair of opposing extended nozzle drag bit legs are positioned adjacent a pair of opposed tungsten carbide roller cones. The extended nozzle face nearest the hole bottom has a multiplicity of diamond inserts mounted therein. The diamond inserts are strategically positioned to remove the ridges between the kerf rows in the hole bottom formed by the inserts in the roller cones.

Abstract: A drill bit is disclosed for maintaining a desired direction of drilling or to reduce the deviation already established. The drill bit includes a plurality of legs with each leg having a cone cutter rotatively supported thereon. A plurality of annular rows of cutting inserts are circumferentially mounted on the conical surface of each cutter. Each cone cutter further includes a heel portion adjacent the base of the conical surface. The heel portion is of sufficient mass to support the gage row of cutting elements. The gage row of each cone extends further out from the cone axis than any of the intermediate adjacent rows in such a manner that the annular area of the hole bottom cut by the gage inserts is lower than any other area cut by the intermediate rows of cutting inserts. This extended gage row construction enables the gage inserts to cut into any sloping wall to produce a sharp corner and bring the hole back into line with the drill string.

Abstract: A Zublin type rotary drill bit is disclosed having a main body rotating about a main axis. The bit body includes a journl pin extending downwardly therefrom, with the journal pin forming a second axis disposed at an angle with respect to the main axis. The journal pin has a cutter rotatively mounted thereon, with the cutter having a spherical outer surface which has a plurality of inner rows of tungsten carbide mounted thereon. The gage row of the cutter is also formed on the spherical outer surface and defines a plane intersecting the intersection of the main and second axes. The cutter gage row is formed by a plurality of inserts having synthetic diamond cutting surfaces, which are facing downwardly toward the apex of the cutter, in order to scrape the sides of the bore hole during the downwardly traveling portion of the gage insert travel cycle.

Abstract: A rock bit for drilling hard formations has a bit body with a plurality of rolling cone cutters mounted on it for rotation with rotation of the bit body. The cutters each have a plurality of recesses in their outer surfaces and a tungsten carbide insert is interference fitted into each of said recesses. A large diameter rock bit has such inserts larger than about 3/4 inch diameter and a cavity is provided in the cylindrical base of such an insert. The cavity has a volume in the range of from about 15 to 30% of the volume of the cylindrical base and extends into the cylindrical base a distance of at least about 40% of the diameter of the base. The depth of the recess is more than half of the length of the portion of the insert that grips the recess in which it is inserted. Large savings in expensive tungsten carbide can be made without decreasing performance of the tungsten carbide inserts.