The subject matter of the invention is a bit holder for an earth working machine, in particular a road milling machine, having a support member onto which an insertion projection is indirectly or directly attached on an insertion projection side, the insertion projection comprising at least one convex abutment surface and one pressure surface. In a bit holder of this kind, working forces can be dissipated in stress-optimized fashion into an attached base part when provision is made that the insertion projection comprises two convex abutment surfaces that are arranged at a distance from one another.

The subject matter of the invention is a bit holder for an earth working machine, in particular a road milling machine, having a support member onto which an insertion projection is indirectly or directly attached on an insertion projection side, the insertion projection comprising at least one convex abutment surface and one pressure surface. In a bit holder of this kind, working forces can be dissipated in stress-optimized fashion into an attached base part when provision is made that the insertion projection comprises two convex abutment surfaces that are arranged at a distance from one another.

A holder block assembly for a drum-type cutting tool has a holder block and a sleeve that is removably held in the holder block to carry a cutter bit. The sleeve includes a shank received in a hole in a cutter block and a nut threaded on the shank. The nut is turned by a hand tool to extract the sleeve from the holder block.

A replaceable tool support is disclosed. The tool support may be configured to be mounted to a base member of a cutting head, which may be mountable to a tool drum used in hard rock mining applications. The tool support may have an annular body having a first end face side. The tool support may also have a plurality of cutting bit carriers disposed spaced apart from each other on the first end face side. In addition, the tool support may have a plurality of cutting bits. Each of the plurality of cutting bits may be rotatably supported by one of the plurality of cutting bit carriers.

A replaceable tool support is disclosed. The tool support may be configured to be mounted to a base member of a cutting head, which may be mountable to a tool drum used in hard rock mining applications. The tool support may have an annular body having a first end face side. The tool support may also have a plurality of cutting bit carriers disposed spaced apart from each other on the first end face side. In addition, the tool support may have a plurality of cutting bits. Each of the plurality of cutting bits may be rotatably supported by one of the plurality of cutting bit carriers.

A protective wear sleeve for a cutting tool assembly that includes a solid body that has a shaft portion, a radial collar portion, and a central bore that defines a central axis. The shaft has a forward end and a rearward end, wherein the radial collar is integral with the forward end. The radial collar has a ring support surface that faces at least partially in an outward radial direction. The forward end of the shaft and the radial collar together define a tooth support surface that faces in a forward direction and has an outer diameter. At least one wear ring is disposed on the ring support surface and extends around the radial collar. The at least one wear ring has a hardness greater than that of the radial collar and has an outer diameter greater than that of the outer diameter of the tooth support surface.

Improvements in previous bit assembly components including shortened slotted shanks and shortened base block bore receiving portions disclose relationships between shank differential interference portions and the corresponding base block bores. Changes in the differences in interference angles lead to changes in slot width, length and steel hardnesses in order to provide necessary retaining forces between the shank and base block bore.

Improvements in previous bit assembly components including shortened slotted shanks and shortened base block bore receiving portions disclose relationships between shank differential interference portions and the corresponding base block bores. Changes in the differences in interference angles lead to changes in slot width, length and steel hardnesses in order to provide necessary retaining forces between the shank and base block bore.

A tool holder insertion device includes a frame extending from a proximal end to a distal end, the frame including first and second longitudinal arms extending between the distal end and the proximal end. The frame also includes a distal transverse arm connected to respective distal ends of the first and second longitudinal arms, a proximal transverse arm opposite the distal transverse arm, and an internal space extending from the distal transverse arm, the internal space forming an insertion opening. The tool holder insertion device also includes a drive assembly fixed to the frame, the drive assembly including a pushing surface that is movable within the internal space toward the distal end of the frame.

A bit removal device may include a support, an extractor coupled to the support, and an actuator. The support is configured to engage a bit holder from a front side of the bit holder. The extractor is configured to engage a bit from the front side of the bit holder. The actuator is configured to move the extractor relative to the support to extract the bit from the bit holder.