Chisel Holder
AssigneeWirtgen GmbH
InventorsThomas Lehnert, Karsten Buhr, Cyrus Barimani, Günter Hähn
Life of this patent
Estimating the term…
Abstract
The invention relates to a bit holder for an earth working machine, in particular a surface miner, a road milling machine, or the like, having a holding projection that comprises a bit receptacle and/or carries a cutting element. In order to improve the operating reliability of an earth working machine, provision is made according to the present invention that the holding projection has, behind the cutting element or behind a receiving region of the bit receptacle in the tool advance direction, a wear protection element having a hard-material element in order to provide an emergency-mode property.
Claims29
1-17. (canceled)
A bit holder for an earth working machine, comprising:
- a holding projection including a bit receptacle, the bit receptacle including a receiving end for receiving a cutting bit;
- and
- a wear protection element attached to the holding projection behind the receiving end of the bit receptacle, the wear protection element including a hard-material element harder than the holding projection, the hard-material element being arranged to engage the earth in the event of excessive wear or breakage of the cutting bit.
A wear protection element for a bit holder for an earthworking machine, comprising:
- a carrier including an underside, an upper side, a front side, a rear side, and first and second lateral sides;
- the underside including a concave placement surface having a concave curvature in lateral cross-section;
- the upper side including a recess defined in part by forward and rearward supporting surfaces;
- and
- a hard-material element, harder than the carrier, received in the recess and supported by the forward and rearward supporting surfaces.
A milling drum assembly for an earthworking machine, comprising:
- a milling drum having a circumference;
- a plurality of cutting tool assemblies arranged around the circumference of the milling drum, each cutting tool assembly including:
- a bit holder including a holding projection, the holding projection including a bit receptacle defined therein, the holding projection including a radially outer side;
- a cutting bit received in the bit receptacle and extending forward in a tool advance direction;
- and
- a hard-material element attached to the holding projection behind the cutting bit and extending outward from the radially outer side of the holding projection, the hard-material element being harder than the holding projection;
- and
- wherein radially outer parts of the hard-material elements are arranged on an inner reference circle having an inner radius, and radially outer parts of the cutting bits are arranged on an outer reference circle having an outer radius, the inner radius being smaller than the outer radius.
Dependencies are inferred from the claim text.