A drilling tool, in particular a rock drill, extends along a longitudinal axis and includes a drill head, an insertion end, a main body, a sleeve element, a conveying portion arranged between the drill head and the insertion end, and at least one conduit that extends along the conveying portion. The conduit is located radially between the sleeve element and the main body. The sleeve element is rotatably mounted on the main body.

A glass article (100) includes a core layer (102) formed from a core glass composition with a core coefficient of thermal expansion (CTE) and first (104) and second (106) cladding layers fused to first and second major surfaces of the core layer (102) and formed from a clad glass composition comprising a clad CTE. An aperture (120) extends through each of the core layer (102), the first cladding layer (104), and the second cladding layer (106). The clad CTE is less than the core CTE such that each of the first (104) and second (106) cladding layers is under a compressive stress and the core layer (102) is under a tensile stress. A flexural strength of the glass article (100) can be at least about 75 MPa. A peak load sustainable by the glass article (100) in a modified ring-on-ring test can be at most 96.5% less than a peak load sustainable by a reference glass article in the modified ring-on-ring test.

A work machine unit includes: a support member assembled to an end effector connection part of an operating machine; a work machine part assembled to one end of the support member; and a linear guide disposed at another end of the support member across its connection to the end effector connection part from the support member, arranged in parallel to an axial direction of the work machine part, and configured to abut against a work object or its peripheral structural object. Further, the linear guide is passed through a through-hole formed in the support member, and the support member is configured to move in the axial direction of the work machine part as guided by the linear guide.

A magnetic base for an electric machine tool, in particular for a magnetic core drilling machine. A body that is accommodated in a receiving space. At least one first magnet coil constituting an electromagnet, a coil winding of the at least one first magnet coild being wound on a bobbin and a magnetic force of which is switchable between a maximum resultant holding force and a minimum resultant holding force. The coil winding of the magnet coil has two end sections that are each connected to a connecting cable that serves to make electrical contact between the magnetic coil and the electric machine tool. The body has a first side adapted to be coupled to the electric machine tool and has an opposite second side adapted to be placed on a workpiece that is to be processed. End sections of the coil winding are connected to the connecting cables.

A method and apparatus is provided to rehabilitate and beautify cracked concrete surfaces by adding channels that look like the cracks to the surface.

A method and apparatus is provided to rehabilitate and beautify cracked concrete surfaces by adding channels that look like the cracks to the surface.

A method for operating a machine tool that includes an electric motor for driving a drilling tool and an open- and closed-loop controller for open- and closed loop control of the motor power. The method includes: operating the machine tool in a tapping mode at a first rotational speed value, where the first rotational speed value is lower than a predetermined idling speed value of the electric motor; detecting a predetermined first threshold value for the motor current; reducing the motor current to a predetermined second threshold value when the first threshold value is exceeded; operating the machine tool at a second rotational speed value, where the second rotational speed value is lower than the first rotational speed value; operating the electric motor at a predetermined motor current value; and operating the controller for closed loop control of the motor power via the motor current with an oscillating action.

A method for operating a machine tool that includes an electric motor for driving a drilling tool and an open- and closed-loop controller for open- and closed loop control of the motor power. The method includes: operating the machine tool in a tapping mode at a first rotational speed value, where the first rotational speed value is lower than a predetermined idling speed value of the electric motor; detecting a predetermined first threshold value for the motor current; reducing the motor current to a predetermined second threshold value when the first threshold value is exceeded; operating the machine tool at a second rotational speed value, where the second rotational speed value is lower than the first rotational speed value; operating the electric motor at a predetermined motor current value; and operating the controller for closed loop control of the motor power via the motor current with an oscillating action.

A tool head capable of introducing deep recesses into hard and brittle material such as glass and glass ceramics is provided. The tool head includes a hollow cylindrical abrasive body merging into a hollow shank. The hollow cylindrical abrasive body has an end face with a central abrasive area at the location of a cylinder axis. The central abrasive area is connected with the inner wall surface of the hollow cylindrical abrasive body by at least one web. The end face of the abrasive body, the web, and at least a portion of the outer wall surface of the abrasive body are covered with abrasive. The hollow shank has at least one opening to the interior between the at least one web and the inner wall surface of the abrasive body.

A method for setting a screw, which has an external thread in a front region and a drive in a rear region for introducing a torque into the screw, in a drilled hole in a substrate of a mineral material includes producing an internal thread in the drilled hole by a threaded drill provided with a cutting thread and then introducing the screw into the drilled hole and in so doing the external thread of the screw is screwed into the internal thread, produced by the threaded drill, in the drilled hole. The external diameter of the cutting thread of the threaded drill is smaller than the external diameter of the external thread of the screw.