Abstract: In the seal gland in a rotating cone drill bit, the O-ring is initially compressed between the journal and a central portion of the gland which has a cross-section parallel to the journal. These two concentric surfaces provide a minimum amount of contact pressure for a given amount of squeeze than other configurations. Chamfers connect the central portion to the sidewalls of the gland, so that after the seal has worn in use, it will ride up onto the chamfers, where additional squeeze to the seal. This allows the seal to operate in a standard regime during the first part of its lifetime and to automatically shift to a more compressed mode as the seal wears.

Abstract: A roller-cone rock bit in which the compensation reservoir is integrated with a hydrostatically-asymmetric seal, such as a V-seal, which provides pressure relief. This seal not only relieves overpressure during filling, and when the grease thermally expands as the bit first goes downhole, but also compensates transient overpressures during operation.

Abstract: In the seal gland in a rotating cone drill bit, the O-ring is initially compressed between the journal and a central portion of the gland which has a cross-section parallel to the journal. These two concentric surfaces provide a minimum amount of contact pressure for a given amount of squeeze than other configurations. Chamfers connect the central portion to the sidewalls of the gland, so that after the seal has worn in use, it will ride up onto the chamfers, where additional squeeze to the seal. This allows the seal to operate in a standard regime during the first part of its lifetime and to automatically shift to a more compressed mode as the seal wears.

Abstract: In the seal gland in a rotating cone drill bit, the O-ring is initially compressed between the journal and a central portion of the gland which has a cross-section parallel to the journal. These two concentric surfaces provide a minimum amount of contact pressure for a given amount of squeeze than other configurations. Chamfers connect the central portion to the sidewalls of the gland, so that after the seal has worn in use, it will ride up onto the chamfers, where additional squeeze to the seal. This allows the seal to operate in a standard regime during the first part of its lifetime and to automatically shift to a more compressed mode as the seal wears.

Abstract: A rotary cone drill bit for forming a borehole having a body with an underside and an upper end portion adapted for connection to a drill string. The drill bit rotates around a central axis of the body. A number of angularly-spaced arms are integrally formed with the body and depend therefrom. Each arm has an inside surface with a spindle connected thereto and an outer shirttail surface. Each spindle projects generally downwardly and inwardly with respect to the central axis, has a generally cylindrical upper end portion connected to the inside surface, and has an inner sealing surface within the upper end portion. A number of rotary cone cutters equal to the number of arms are each mounted on one of the spindles.

Abstract: A rotary cone drill bit for forming a borehole having a body with an underside and an upper end portion adapted for connection to a drill string. The drill bit rotates around a central axis of the body. A number of angularly-spaced arms are integrally formed with the body and depend therefrom. Each arm has an inside surface with a spindle connected thereto and an outer shirttail surface. Each spindle projects generally downwardly and inwardly with respect to the central axis, has a generally cylindrical upper end portion connected to the inside surface, and has an inner sealing surface within the upper end portion. A number of rotary cone cutters equal to the number of arms are each mounted on one of the spindles.

Abstract: A rotary cone drill bit for forming a borehole having a body with an underside and an upper end portion adapted for connection to a drill string. The drill bit rotates around a central axis of the body. A number of angularly-spaced arms are integrally formed with the body and depend therefrom. Each arm has an inside surface with a spindle connected thereto and an outer shirttail surface. Each spindle projects generally downwardly and inwardly with respect to its associated arm, has a generally cylindrical upper end portion connected to the associated inside surface, and has an inner sealing surface on the upper end portion. A number of rotary cone cutters equal to the number of arms are each mounted on respective spindles.