A double headed drill bit for a cutting element carried on a rotary drum member of a continuous mining machine is provided according to the invention. The drill bit is formed from a length of hardened material and includes a first tapered bit portion extending from a point located at a first end of the length of hardened material toward a mid-portion of the length of hardened material, and a second tapered bit portion extending from a point located at a second end of the length of hardened material toward the mid-portion of the length of hardened material. The drill bit is removably positioned within the central opening of an annular sleeve located in a block member mounted on the rotary drum member. One of the first tapered bit portion or second tapered bit portion extends outwardly from the annular sleeve and the other of the first tapered bit portion or second tapered bit portion extends into the shank portion the annular sleeve. Positive retention means for securing the drill bit against longitudinal movement within the annular sleeve are also provided in the form of a retaining clip which engages an annular groove at the mid-portion of the drill bit.

A double headed drill bit for a cutting element carried on a rotary drum member of a continuous mining machine is provided according to the invention. The drill bit is formed from a length of hardened material and includes a first tapered bit portion extending from a point located at a first end of the length of hardened material toward a mid-portion of the length of hardened material, and a second tapered bit portion extending from a point located at a second end of the length of hardened material toward the mid-portion of the length of hardened material. The drill bit is removably positioned within the central opening of an annular sleeve located in a block member mounted on the rotary drum member. One of the first tapered bit portion or second tapered bit portion extends outwardly from the annular sleeve and the other of the first tapered bit portion or second tapered bit portion extends into the shank portion the annular sleeve. Positive retention means for securing the drill bit against longitudinal movement within the annular sleeve are also provided in the form of a retaining clip which engages an annular groove at the mid-portion of the drill bit.

In a system for the tracking of milling material, comprising a milling machine for milling a section of a ground pavement in a milling operation, a means of transport which can be loaded with the milling material removed during milling of the section of the ground pavement and which can be used to transport away the removed milling material, a detection device for detecting data signals relating to the milling material, it is provided for the following features to be achieved: the detection device transmits the data signals relating to the milling material to a marking device, and the marking device, depending on the data signals relating to the milling material transmitted, marks the milling material deposited on the means of transport, or the means of transport loaded with the milling material, with a marking means.

In a system (3) for the tracking of milling material (26), comprising a milling machine (1) for milling a section (28) of a ground pavement (29) in a milling operation, a truck (14) for loading and transporting away the milling material (26) removed during milling of the section (28) of the ground pavement (29), a deposition site (24) for depositing the milling material (26) transported away by the truck (14), a first detection device (18) for detecting data signals relating to the milling material (26), it is specified for the following features to be achieved: that a second detection device (20) detects position data of the deposition site of the milling material (26), wherein the first and the second detection device (18, 20) transmit the data signals (60) relating to the milling material (26) and the position data of the deposition site (24) to a documentation device (22) which links the position data with the data signals relating to the milling material (26).

In a drum housing for a working drum of a construction machine or mining machine, said working drum being provided with tools and rotating about a drum axis, with a housing shell which at least partially encloses the circumference of the working drum, and with at least one inspection opening for a monitoring device arranged in the housing shell, wherein said monitoring device inspects the condition of the working drum or the tools thereof, it is provided for the following features to be achieved: a closing mechanism is arranged on the outside of the housing shell, said closing mechanism enabling closure of the at least one inspection opening.

In a drum housing for a working drum of a construction machine or mining machine, said working drum being provided with tools and rotating about a drum axis, with a housing shell which at least partially encloses the circumference of the working drum, and with at least one inspection opening for a monitoring device arranged in the housing shell, wherein said monitoring device inspects the condition of the working drum or the tools thereof, it is provided for the following features to be achieved: a closing mechanism is arranged on the outside of the housing shell, said closing mechanism enabling closure of the at least one inspection opening.

A cutting bit for a bit assembly secured to a cutter head includes a cutting end, a shank extending along a bit axis, and a shoulder positioned between the cutting end and the shank. The shoulder includes an outer edge defining a perimeter, a shoulder end surface defining a shoulder plane, a first inclined surface and a second inclined surface. The first inclined surface is positioned between the outer edge and the shoulder end surface. The first inclined surface extends along the perimeter and is oriented at a first acute angle relative to the shoulder plane. The second inclined surface is positioned between the shoulder end surface and the first inclined surface. The second inclined surface is oriented at a second acute angle relative to the shoulder plane, and the second acute angle is smaller than the first acute angle.

A cutting bit for a bit assembly secured to a cutter head includes a cutting end, a shank extending along a bit axis, and a shoulder positioned between the cutting end and the shank. The shoulder includes an outer edge defining a perimeter, a shoulder end surface defining a shoulder plane, a first inclined surface and a second inclined surface. The first inclined surface is positioned between the outer edge and the shoulder end surface. The first inclined surface extends along the perimeter and is oriented at a first acute angle relative to the shoulder plane. The second inclined surface is positioned between the shoulder end surface and the first inclined surface. The second inclined surface is oriented at a second acute angle relative to the shoulder plane, and the second acute angle is smaller than the first acute angle.

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.

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.