Abstract: Described are methods of preparing reduced 3,7-diamino-10H-phenothiazine (DAPTZ) compounds of formula: wherein: R1 and R9 are independently selected from: —H; C1-4alkyl; C2-4alkenyl; and halogenated C1-4alkyl; each of R3NA and R3NB is independently selected from: —H; C1-4alkyl; C2-4alkenyl; and halogenated C1-4alkyl; each of R7NA and R7NB is independently selected from: —H; C1-4alkyl; C2-4alkenyl; and halogenated C1-4alkyl; each of HX1 and HX2 is independently a protic acid; and pharmaceutically acceptable salts, solvates, and hydrates thereof. These methods are particularly useful for producing stable reduced forms, and with high purity. The stability and purity are especially relevant for pharmaceutical compositions for the treatment of disease. The compounds are useful for treatment of e.g. tauopathies, such as Alzheimer's disease, and also as prodrugs for the corresponding oxidized thioninium drugs.

Abstract: A method for drilling out a plug includes directing a hybrid rotary cone drill bit having a plurality of rotary cones into a borehole lined with a casing. A body of the plug is drilled out using milled teeth formed in the hybrid rotary cone drill bit. A slip of the plug is drilled out using cutter inserts secured into the rotary cone where the slip contacts the casing. The drilled out plug is directed up the borehole using a drilling fluid.

Abstract: A hybrid rotary cone drill bit includes a plurality of legs. A bearing shaft extends from each leg, and a rotary cone is rotationally coupled to each bearing shaft. At least one rotary cone includes a nose row of cutting structures, an inner row of cutting structures, and a gage row of cutting structures. The nose row and the inner row of cutting structures are formed of milled teeth. The gage row of cutting structures is formed of cutter inserts.

Abstract: A rotary cone drill bit includes: a body, a leg depending from the body, a bearing shaft extending from the leg and a cone mounted to the bearing shaft. The leg includes a leading transitional surface. A bottom surface of a hard material plate is attached to a substantially conforming surface of the leg in a position where the hard material plate is disposed on a floor surface formed in or by the leading transitional surface of the leg.

Abstract: A hybrid rotary cone drill bit includes a plurality of legs. A bearing shaft extends from each leg, and a rotary cone is rotationally coupled to each bearing shaft. At least one rotary cone includes a nose row of cutting structures, an inner row of cutting structures, and a gage row of cutting structures. The nose row and the inner row of cutting structures are formed of milled teeth. The gage row of cutting structures is formed of cutter inserts.

Abstract: A method for drilling out a plug includes directing a hybrid rotary cone drill bit having a plurality of rotary cones into a borehole lined with a casing. A body of the plug is drilled out using milled teeth formed in the hybrid rotary cone drill bit. A slip of the plug is drilled out using cutter inserts secured into the rotary cone where the slip contacts the casing. The drilled out plug is directed up the borehole using a drilling fluid.

Abstract: To address issues of durability of pressure compensation systems in roller cone rock bits, a composite diaphragm of a pressure compensation system for a roller cone drill bit includes an inner surface that defines an inner cavity and is formed of a first elastomeric material. The inner cavity is configured to serve as a lubricant reservoir. An external surface is disposed opposite the inner surface and is formed of a second elastomeric material that is different than the first elastomeric material.

Abstract: An earth boring drill bit having an alternate path to allow cuttings to be ejected or evacuated from the drill bit and up the bore hole is disclosed. The evacuation hole of the present disclosure allows larger sized cuttings to evacuate from the bit without having to be continually ground by rolling cone cutters until the cuttings are small enough to follow a path around the edge of the shirttail of the bit and up the borehole. A cuttings restrictor is disposed at the inlet of the evacuation hole. The cuttings restrictor ensures that only cuttings that are sized to move completely through the evacuation hole and exit the drill bit are allowed to enter the evacuation hole.

Abstract: A method for applying a coating to a surface of an industrial tool includes applying a coating including a thermosetting polymer to a metallic surface of the industrial tool. The coating is cured to form a bond between the coating and the metallic surface. According to certain embodiments, the thermosetting polymer may be combined with an additive. The additive may be selected to improve the chemical resistance or wear resistance of the coating and thereby improve the chemical resistance or wear resistance of certain surfaces of the industrial tool.

Abstract: A bit body for a drill bit for horizontal directional drilling includes a pair of legs and a small wedge member disposed between the pair of legs. A roller cone is rotatably mounted to each bearing shaft extending from a respective leg. The roller cones support full coverage cutting structures. A center jet nozzle is configured to direct drilling fluid between the pair of roller cones. A stabilizer member maintains an upright drilling position of the drill bit within the borehole.

Abstract: A hybrid rotary cone drill bit includes a plurality of legs. A bearing shaft extends from each leg, and a rotary cone is rotationally coupled to each bearing shaft. At least one rotary cone includes a nose row of cutting structures, an inner row of cutting structures, and a gage row of cutting structures. The nose row and the inner row of cutting structures are formed of milled teeth. The gage row of cutting structures is formed of cutter inserts.

Abstract: In an embodiment, a rotary cone drill bit comprises: a body, a leg depending from the body, a bearing shaft extending from the leg and a cone mounted to the bearing shaft. The leg includes a leading transitional surface. A bottom surface of a hard material plate is attached to a substantially conforming surface of the leg in a position where the hard material plate is disposed on a floor surface formed in or by the leading transitional surface of the leg.

Abstract: An earth boring drill bit having an alternate path to allow cuttings to be ejected or evacuated from the drill bit and up the bore hole is disclosed. The evacuation hole of the present disclosure allows larger sized cuttings to evacuate from the bit without having to be continually ground by rolling cone cutters until the cuttings are small enough to follow a path around the edge of the shirttail of the bit and up the borehole. A cuttings restrictor is disposed at the inlet of the evacuation hole. The cuttings restrictor ensures that only cuttings that are sized to move completely through the evacuation hole and exit the drill bit are allowed to enter the evacuation hole.

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.

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.

Abstract: A sealing system is provided for a drill bit including a bit head and a rotating bit cone. The sealing system includes a seal gland and a seal retained within the seal gland. The seal gland is defined by a radial cone surface and is further defined by 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.

Abstract: A sealing system is provided for a drill bit including a bit head and a rotating bit cone. The sealing system includes a seal gland and a seal retained within the seal gland. The seal gland is defined by a radial cone surface and is further defined by 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.

Abstract: A sealing system is provided for a drill bit including a bit head and a rotating bit cone. The sealing system includes a seal gland and a seal retained within the seal gland. The seal gland is defined by a radial cone surface and is further defined by 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.