A wear prognosis method and a maintenance method for an earth working machine are disclosed, along with an apparatus for performing the method. Provision is made that the current wear state of one or more earth working tools is sensed. The residual wear capacity until the wear limit is reached is then ascertained from the current wear state.

A rock excavating device includes a shaft and a cutting element. The shaft includes a first portion and a second portion connected to an end of the first portion. The first portion is rotatable about a first axis. The second portion extends along a second axis that is oblique with respect to the first axis. The cutting element includes a cutting edge. The cutting element is supported on the second portion and rotatable about the second axis. Rotation of the first portion of the shaft about the first axis changes the orientation of the second axis and the cutting element.

A rock excavating device includes a shaft and a cutting element. The shaft includes a first portion and a second portion connected to an end of the first portion. The first portion is rotatable about a first axis. The second portion extends along a second axis that is oblique with respect to the first axis. The cutting element includes a cutting edge. The cutting element is supported on the second portion and rotatable about the second axis. Rotation of the first portion of the shaft about the first axis changes the orientation of the second axis and the cutting element.

An extraction tool for removing bullet bits from mining and excavation equipment, including a threaded extraction rod and extractor, a pusher tube.

An extraction tool for removing bullet bits from mining and excavation equipment, including a threaded extraction rod and extractor, a pusher tube.

A machine for excavating rock includes a frame, a cutting device, and a boom. The cutting device includes a cutting disc having a cutting edge, and the cutting disc is rotatable about a cutting device axis. The boom supports the cutting device and includes a first end, a second end, and a boom axis substantially parallel to the cutting device axis. The boom further includes a first portion and a second portion. The first portion is coupled to the frame for rotation about a first pivot axis between a raised position and a lowered position. The second portion is coupled to the cutting device, and the second portion is pivotable about a second pivot axis between a raised position and a lowered position.

A machine for excavating rock includes a frame, a cutting device, and a boom. The cutting device includes a cutting disc having a cutting edge, and the cutting disc is rotatable about a cutting device axis. The boom supports the cutting device and includes a first end, a second end, and a boom axis substantially parallel to the cutting device axis. The boom further includes a first portion and a second portion. The first portion is coupled to the frame for rotation about a first pivot axis between a raised position and a lowered position. The second portion is coupled to the cutting device, and the second portion is pivotable about a second pivot axis between a raised position and a lowered position.

In a method for determining an area milled by at least one construction machine or at least one mining machine by means of a milling drum (2) by means of working a predetermined area in several milling trajectories by at least one machine (1), determining the length of the milling trajectories along which a milling operation has taken place by evaluating the continuous machine positions, adding up the previously milled partial areas taking into account the length of the milling trajectory and the installed width of the milling drum (2), wherein the partial area currently milled along the milling trajectory is checked, either continuously or subsequently, for overlapping or multiple overlapping with any previously milled partial areas, and any partial areas which overlap are deducted, as overlapping areas, from the added-up previously milled partial areas, the total added-up partial areas milled minus the total overlapping areas established give the milled area.

In a method for determining an area milled by at least one construction machine or at least one mining machine by means of a milling drum (2) by means of working a predetermined area in several milling trajectories by at least one machine (1), determining the length of the milling trajectories along which a milling operation has taken place by evaluating the continuous machine positions, adding up the previously milled partial areas taking into account the length of the milling trajectory and the installed width of the milling drum (2), wherein the partial area currently milled along the milling trajectory is checked, either continuously or subsequently, for overlapping or multiple overlapping with any previously milled partial areas, and any partial areas which overlap are deducted, as overlapping areas, from the added-up previously milled partial areas, the total added-up partial areas milled minus the total overlapping areas established give the milled area.

A rock excavating device includes a shaft and a cutting element. The shaft includes a first portion and a second portion connected to an end of the first portion. The first portion is rotatable about a first axis. The second portion extends along a second axis that is oblique with respect to the first axis. The cutting element includes a cutting edge. The cutting element is supported on the second portion and rotatable about the second axis. Rotation of the first portion of the shaft about the first axis changes the orientation of the second axis and the cutting element.