Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

Abstract: A roller cone drill bit is disclosed which includes a bit body adapted to be coupled to a drill string. A bearing journal depends from the bit body. A single roller cone is rotatably attached to the bearing journal. The roller cone has a plurality of inserts disposed at selected positions about the cone. The journal defines a rotation angle with respect to an axis of rotation of the bit such that the roller cone includes a wall contact zone and a bottom contact zone. At least one of the inserts disposed in the wall contact zone has an extension portion terminating in a substantially planar upper surface.

Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.