Percussive rotational impact hammer

A percussive rotational impact hammer assembly for rotating a member, the hammer assembly comprising:

• a generally cylindrical outer casing having a cylindrical interior surface;
• a generally cylindrical hammer member in said outer casing cylindrical interior surface having an interior engagement surface for engaging a member to be rotated, and an outer cylindrical sliding surface with a raised impact face and a raised return face disposed in circumferentially spaced relation;
• a hollow generally cylindrical piston member rotatably mounted concentrically on said hammer sliding surface and having an arcuate sidewall portion with an impact face and a return face disposed in circumferentially spaced relation,
• said hammer member sized and shaped to define an annulus between its said outer cylindrical sliding surface and the interior surface of the outer casing in which said piston rotatably oscillates, and said piston arcuate sidewall dividing the annulus into an impact chamber between said hammer impact face and said piston impact face and a return chamber between said hammer return face and said piston return face;
• and
• fluid conducting ports and passageways in said hammer member and said piston member for conducting pressurized fluid in pathways to alternately pressurize said return chamber and said impact chamber to rotatably oscillate said piston, such that
• upon pressurization of said return chamber said piston is rotated in a first direction to forcefully strike its said impact face on said hammer impact face and the kinetic energy of said piston and rotational movement is transmitted via said hammer member to the member engaged with said interior engagement surface, and upon pressurization of said impact chamber said piston is rotated in a reverse direction.

A downhole percussive rotational impact hammer assembly for rotating a bit, comprising:

• an elongate downhole tool having a generally cylindrical portion with a cylindrical interior surface;
• a generally cylindrical hammer member in said cylindrical interior surface having an interior engagement surface for engaging a bit to be rotated, and an outer cylindrical sliding surface with a raised impact face and a raised return face disposed in circumferentially spaced relation;
• a hollow generally cylindrical piston member rotatably mounted concentrically on said hammer sliding surface and having an arcuate sidewall portion with an impact face and a return face disposed in circumferentially spaced relation,
• said hammer member sized and shaped to define an annulus between its said outer cylindrical sliding surface and said interior surface in which said piston rotatably oscillates, and said piston arcuate sidewall dividing the annulus into an impact chamber between said hammer impact face and said piston impact face and a return chamber between said hammer return face and said piston return face;
• and
• fluid conducting ports and passageways in said hammer member and said piston member for conducting pressurized fluid in pathways to alternately pressurize said return chamber and said impact chamber to rotatably oscillate said piston, such that
• upon pressurization of said return chamber said piston is rotated in a first direction to forcefully strike its said impact face on said hammer impact face and the kinetic energy of said piston and rotational movement is transmitted via said hammer member to the member engaged with said interior engagement surface, and upon pressurization of said impact chamber said piston is rotated in a reverse direction.

A percussive rotational impact wrench assembly for tightening or loosening a member of a threaded connection, comprising:

• a wrench having a body portion with a cylindrical interior surface;
• a generally cylindrical hammer member in said cylindrical interior surface having an interior engagement surface for engaging a member of a threaded connection to be rotated, and an outer cylindrical sliding surface with a raised impact face and a raised return face disposed in circumferentially spaced relation;
• a hollow generally cylindrical piston member rotatably mounted concentrically on said hammer sliding surface and having an arcuate sidewall portion with an impact face and a return face disposed in circumferentially spaced relation,
• said hammer member sized and shaped to define an annulus between its said outer cylindrical sliding surface and said interior surface in which said piston rotatably oscillates, and said piston arcuate sidewall dividing the annulus into an impact chamber between said hammer impact face and said piston impact face and a return chamber between said hammer return face and said piston return face;
• and
• fluid conducting ports and passageways in said hammer member and said piston member for conducting pressurized fluid in pathways to alternately pressurize said return chamber and said impact chamber to rotatably oscillate said piston, such that
• upon pressurization of said return chamber said piston is rotated in a first direction to forcefully strike its said impact face on said hammer impact face and the kinetic energy of said piston and rotational movement is transmitted via said hammer member to the member engaged with said interior engagement surface, and upon pressurization of said impact chamber said piston is rotated in a reverse direction.