A bit holder that includes a front body portion and a shank axially depending from the bottom of the front body portion. The shank of the bit holder includes at least one slot and at least one annular ring disposed partially or nearly circumferentially around the shank. The slotted shank of the bit holder and the at least one annular ring are radially compressible to achieve and maintain an interference fit when inserted into a bore of a base block.

A bit holder and corresponding base block are disclosed wherein a slotted shank of the bit holder includes a reverse taper portion adjacent a distal end thereof. A base block with a bore for receiving said shank includes a corresponding hollow portion of reverse taper configuration that will tend to retain said shank therein.

A unitary bit/holder and/or a bit holder including a body portion and a shank. The body portion and the shank being coaxial and including a bore extending from a forward end of the body portion to the distal end of the shank. The shank further including a segment adjacent a distal end of the shank that includes a plurality of ribs and at least one notch or relief zone between each rib in the plurality of ribs.

Aspects of the present disclosure relate to an apparatus including a drum rotatable about an axis of rotation and a support mount secured to the drum. The apparatus includes a support mount defining first and second fastener openings and first and second anchor openings. A replaceable holding block mounts to the support mount and the replaceable holding block has a front face and a rear face. The replaceable holding block defines a first fastener opening, a second fastener opening, and a tooth opening that extend through the replaceable holding block from the front face to the rear face. The first and second fastener openings of the replaceable holding block align with the first and second fastener openings of the support mount when the replaceable housing block is mounted to the block mounting surface. A tooth is secured to the replaceable holding block at the tooth opening.

A bit holder that includes a front portion and a shank axially depending from the front portion. The front portion having an axial length that is less than the axial length of the shank. A combination bit holder and base block that includes the bit holder with the front portion having an axial length that is less than the axial length of the shank. The base block including a mounting portion and a device receiving portion, the device receiving portion including a length that is the same or less than a length of the mounting portion. The base block having a device receiving portion that includes a length shorter than a length of the mounting portion adapted to provide increased access to the rear of the bit assembly allowing the base blocks to be mounted closer to each other for micro-milling operations. Shortened bit holder shanks are reconfigured from prior art to provide increased holding power between the bit holder shank and base block bore.

An improved base block is disclosed for use mainly in road milling equipment, but also capable of use in trenching equipment and mining equipment. The base mounting portion is shortened in length from such prior art base blocks and has a reduced length device receiving portion extending therefrom that includes a bore therethrough. Rearwardly of the device receiving portion, the base mounting portion includes a reduced diameter semi-bore or curved wall capable of engaging a portion of the shank side wall of a standard length bit/holder shank. Additionally, an angled slot adjacent the rear of the device receiving bore increases access to the rear to aid removal of a bit/holder therefrom.

The invention relates to a bit holder having an insertion projection and having a holding projection having a bit receptacle, the insertion projection comprising a bearing segment and the holding projection comprising a supporting segment. In order to allow the bit holder to be braced in permanent and stable fashion with respect to a base part, provision is made according to the present invention that the supporting segment and/or the bearing segment comprise two supporting surfaces and bearing surfaces, respectively, arranged at an angle to one another; and that the longitudinal center axis of the bit receptacle and the longitudinal axis of the insertion projection enclose an obtuse angle.

The invention relates to a bit holder for an earth working machine, in particular a road milling machine, having a support body onto which a holding portion having a bit receptacle, and oppositely an insertion projection, are shaped. The holding portion is terminated at the end by a wear surface, and the bit receptacle by a centering receptacle opening in bevel fashion toward the wear surface. A centering height, measured in the direction of the longitudinal center axis, between an end of the centering receptacle and the wear surface or a maximum point of a projection projecting beyond the wear surface, is designed in such a way that the ratio between the inside diameter D.sub.i of the bit receptacle and the centering height is less than 8; and/or that the centering height is greater than an axial play of a round-shank bit installable in the bit holder; and that the support body comprises, on its side facing away from the holding portion, at least two bearing surfaces that are at an angle to one another and form a bearing-surface pair.

Reduced wear on the holding portion and a reduced load on the insertion projection, and thus an extension of the service life of the bit holder, are achieved.

A mounting block assembly and method for assembling is disclosed. The mounting block assembly may comprise a mounting block and a toolholder. The mounting block may include a flighting portion, a mounting portion and a protrusion. The mounting portion defines a first bore that is configured to receive a toolholder. The toolholder includes a generally cylindrical sidewall that defines an axis and defines a second bore that is configured to receive a stem of a cutting bit. The sidewall includes a pair of radially outward extending prongs that define a first recess between the prongs. The first recess is configured to interlockably receive the protrusion when the toolholder is disposed in the mounting portion, wherein the interlocked configuration of the toolholder and the mounting block inhibit rotational movement of the toolholder about the axis.

A cutting tool holding mechanism includes a base, a handle and a locking assembly. The base includes an abutting portion, a receiving bore, at least one limiting bore and at least one limiting hole. The limiting hole is disposed at the base and communicated with the limiting bore. The handle abutted against the base includes a sleeved portion and a plurality of positioning surfaces. The locking assembly includes a packing ring, a locking screw, a locking member and a guiding bolt. The locking member received inside the limiting bore includes a screwed hole and a guiding groove. The guiding groove disposed at one side of the locking member and is aligned with the limiting hole when the locking member is disposed inside the limiting bore. The guiding bolt is disposed in the limiting hole and is abutted against the guiding groove to inhibit the locking member from rotating.