Hole saw adapter (10) comprised of an adapter body (12) with a first end equipped with a spindle (14) for fastening to a drive unit, such as a drilling machine, and a second end to receive a hole saw (32) and a central drill (34), in which the adapter body (12) is extended and equipped with a longitudinally running axial groove (16) where the longitudinally running axial groove (16) is at least partially formed as a cross-wise through-running open slit in the adapter body (12). The central drill (34) is fasten to the inner axially displaceable holding part (22) so that it can be made loose, said inner axially displaceable holding part (22) can be displaced in the longitudinally running axial groove (16) in the adapter body (12) and is fastened to an external displacement part (18), as the external displacement part (18) surrounds the adapter body (12) and is set up for a forced axial displacement of the axially displaceable holding part (22) and the central drill (34) in the longitudinally running axial groove (16) for the pushing out of a core (40) that remains in the hole saw (32) after drilling.

A hole cutter has a substantially cylindrical blade body defining a blade body circumference, a cutting edge formed on one end of the blade body, and an axially-elongated slot formed through the substantially cylindrical blade body. The axially-elongated slot is configured to receive chips flowing from the cutting edge within the interior of the blade body and (i) into the slot and/or (ii) through the slot, to prevent the collection of such chips within the interior of the blade body and/or at an interface between the blade body and the work piece. The axially-elongated slot defines a first end adjacent to the cutting edge, a second end axially spaced further from the cutting edge, and a slot area. The hole cutter further defines a total slot area to blade body circumference ratio within the range of about 0.1 to about 0.3 depending on the size of the hole cutter.

A tool attachment, in particular hole saw, for a power tool having a driving axle that is drivable in oscillation. The tool attachment including a connecting device with which the tool attachment is attachable to a power tool such that the driving axle thereof and a tool axis essentially coincide. A work area has teeth that are at least partially circular in design and adjoin a hollow, cylindrical base. At least two openings formed in the base, the at least two openings constitute at least 60%, at least 80%, or at least 90% of the area of the base.

A tool holder for a machine tool, in particular for a core drilling machine, having a hollow shaft which has, at one end for coupling to the drive of the machine tool, a connector and, at the other end, a receiving opening with a plurality of openings in which locking elements are accommodated which are radially adjustable between a clamping position and an release position for securing a tool accommodated in the receiving opening. A switching sleeve is provided, which is adjustably mounted on the hollow shaft between a first switching position and a second switching position, a first subset of the locking elements being provided in the first switching position for locking the tool in the receiving opening, and a second subset of the locking elements being provided in the second switching position for locking the tool in the receiving opening, while the adjustment of the respective remaining locking elements is deactivated.

Disclosed is a hole cutter including a unit cutting edge, the unit cutting edge including a front surface portion, an inside surface portion, an outside surface portion, and a rear surface portion. The front surface portion includes a first machined surface; and a second machined surface which has a structure which is formed with a surface distinguished from the first machined surface with respect to a first boundary line and is connected to the first machined surface along the first boundary line. The rear surface portion includes a third machined surface; and a fourth machined surface which has a structure which is formed with a surface distinguished from the third machined surface with respect to a second boundary line and is connected to the third machined surface along the second boundary line.

A hole cutter has a cylindrical blade body including a cutting edge and one or more axially-elongated apertures formed within a side wall of the blade body. The axially-elongated aperture is configured to receive a lever, such as a screwdriver, therethrough. Each axially-elongated aperture includes a first fulcrum axially spaced adjacent to the cutting edge, a second fulcrum axially spaced further away from the cutting edge than the first fulcrum, and optionally a third fulcrum axially spaced between the first and second fulcrums. A lever, such as a screwdriver, can be inserted into the aperture and placed against each of the fulcrums to lever slugs out of the interior of the blade body.

A quick change tool includes a tool element, an elongate body having a drive shaft and attaching means for attaching the tool element to the body, and a receiving element for attaching to the tool element. The receiving element includes a through-hole for receiving the body by sliding through the receiving element in the longitudinal direction of the body. The receiving element is configured to co-act with the attaching means to lock the tool element relative to the body at least in an axial direction of the drive shaft. The attaching means includes a resiliently movable locking pin arranged spring-mounted in the body. The receiving element comprises a locking hole configured to receive the locking pin therein in a snapping manner. A pin guiding groove extends between a receiving opening of the through-hole and the locking hole for guiding the locking pin from the receiving opening to the locking hole.

A hole cutter has a cylindrical blade body including a cutting edge and one or more axially-elongated apertures formed within a side wall of the blade body. The axially-elongated aperture is configured to receive a lever, such as a screwdriver, therethrough. Each axially-elongated aperture includes a first fulcrum axially spaced adjacent to the cutting edge, a second fulcrum axially spaced further away from the cutting edge than the first fulcrum, and optionally a third fulcrum axially spaced between the first and second fulcrums. A lever, such as a screwdriver, can be inserted into the aperture and placed against each of the fulcrums to lever slugs out of the interior of the blade body.

A hole saw including a plurality of sidewall openings is provided. The sidewall openings are shaped and grouped in patterns that improve debris ejection of the hole saw and that allow for easy access to the interior of the hole saw for manual debris removal by the user. The opening groups are space from each other by larger uninterrupted areas such that the hole saw has a high strength despite the number and size of openings provided in the saw sidewall.

Device for holes and trepans cutting containing a movable platform, a mechanism of rotation and feeding of the cutting tool installed on the platform, a box-shaped repair cabin with a through hole in a vertical wall thereof and, accommodating a positioning sleeve with an inner flange facing the inside of the repair cabin and an outer flange fixed outside the repair cabin. A mounting fixture secured on the inner flange of the positioning sleeve comprises a mounting plate fixed on the inner flange of the positioning sleeve. A rotating positioning plate is pivotally installed on the mounting plate. The mounting plate and the rotating positioning plate are provided with a mechanism for fixing in the closed position. The movable platform is provided with height-adjustable rotatable wheel supports. A catcher is fixed on the outer flange of the positioning sleeve for primary storage of cut trepans and collection of chips.