An earth-boring tool includes a tool body configured to rotate in a wellbore and carrying at least one extendable element. The at least one extendable element is configured to move between a retracted position and an extended position projecting radially beyond the tool body. The at least one extendable element has a mating surface. The earth-boring tool includes a support structure located in the tool body and having a support surface that is located and configured to face the mating surface of the at least one extendable element when the at least one extendable element is in the extended position. The support surface of the support structure is configured to bear at least a portion of the tangential forces acting on the extendable element during rotation of the earth-boring tool in the wellbore when the at least one extendable element is in the extended position.

An earth-boring tool includes a tool body configured to rotate in a wellbore and carrying at least one extendable element. The at least one extendable element is configured to move between a retracted position and an extended position projecting radially beyond the tool body. The at least one extendable element has a mating surface. The earth-boring tool includes a support structure located in the tool body and having a support surface that is located and configured to face the mating surface of the at least one extendable element when the at least one extendable element is in the extended position. The support surface of the support structure is configured to bear at least a portion of the tangential forces acting on the extendable element during rotation of the earth-boring tool in the wellbore when the at least one extendable element is in the extended position.

An earth-boring tool includes a tool body configured to rotate in a wellbore and carrying at least one extendable element. The at least one extendable element is configured to move between a retracted position and an extended position projecting radially beyond the tool body. The at least one extendable element has a mating surface. The earth-boring tool includes a support structure located in the tool body and having a support surface that is located and configured to face the mating surface of the at least one extendable element when the at least one extendable element is in the extended position. The support surface of the support structure is configured to bear at least a portion of the tangential forces acting on the extendable element during rotation of the earth-boring tool in the wellbore when the at least one extendable element is in the extended position.

The invention relates to an earth drilling device with a housing, a percussion piston which can be moved back and forth in the housing and a supply line for an operating medium for moving the percussion piston, wherein the supply line is arranged at the end of the housing, and the end of the housing tapers backwards in the longitudinal direction, in particular conically, in the region of the supply line and at the end with the supply line there is a connection feature by means of an opening formed at the end which is at least partially radially accessible.

The invention relates to an earth drilling device with a housing, a percussion piston which can be moved back and forth in the housing and a supply line for an operating medium for moving the percussion piston, wherein the supply line is arranged at the end of the housing, and the end of the housing tapers backwards in the longitudinal direction, in particular conically, in the region of the supply line and at the end with the supply line there is a connection feature by means of an opening formed at the end which is at least partially radially accessible.