A drill stand for a portable core drill has a base plate (2) with an elongate opening (3) for securing the base plate (2) on a workpiece and with at least one reinforcing chamber (8a, 8b) that is closed along its edges extending parallel to the longitudinal axis (A) of the annular core bit of the core drill.

A seed drill comprising at least one metering device driven by a mechanism equipped with an input shaft, with a pinion and with a control handle. The seed drill is notable in that the control handle is connected in terms of rotation to the input shaft. The seed drill makes it easier to check the operation of the metering device.

An engaging portion, formed at an axial end of an intermediate member, is engageable with a slide sleeve. A cylinder has an elongated hole with an axial length longer than a shifting distance of the intermediate member. The slide sleeve includes an annular member and a slide member. The annular member has an inner cylindrical wall engageable with the engaging portion of the intermediate member and a projection extending in a radially outward direction passing through the elongated hole beyond an...

A drill bit capable of axial cutting as well as side cutting, having a generally cylindrical elongate body with a bit diameter, includes a frontmost drilling end for axial cutting, a cutting section extending from the drilling end for side cutting, and a shank extending from the cutting section. The cutting section is helically cut at a helix angle of substantially 15.degree..+-.2.degree. to form one pair of diametrically opposite helical flutes whose outermost edges are sharpened to form respec...

A rock drill including a drilling rod (2), a cup-shaped drilling head (5) secured to the drilling rod (2) at one of its ends, and connection elements including at least one radially projecting, entraining web (8) associated with the drilling rod (2) and received in at least one axially extending entrain slot (9) which is formed in an entrain surface of the cup-shaped drilling head (5) for securing the drilling head (5) to the drilling rod (2) for joint rotation therewith and for a limited axial ...

A hammer drill with rolling contact at the contact surfaces for transmission of axial force between a drive shaft and hammer shaft. In the case of ball bearings, point contact is obtained. In the case of roller bearings, line contact is obtained. The area of contact is thus close to zero as opposed to a relatively large area in engagement systems using toothed surfaces. Use of point or line contact reduces heat generation and reduces energy loss due to friction.

An impact drill minimizing transmission of vibration to a handle gripped by a user's hand. A spindle extends through a main frame and is movable in its axial direction and rotatable about its axis. A first ratchet is rotatable and axially movable together with the spindle. A second ratchet is axially movable but unrotatable. In an impact drilling mode, the first ratchet is brought into abutment with the second ratchet so that the spindle is reciprocally moved in the axial direction.

A rock drill (1) for cutting rock comprising an elongated, helical shaft (2), which has, at one end, an insertion part (3) and, at the end opposite, a tool head (4) with cutters (5) made of hard material, wherein the helical shaft (2) is at least partially coated with a colored layer (7a, 7b) and the layer forms a lengthwise running wear indicator marking (8) inside the helical groove (8).

An impact drill includes a first ratchet rotating along with a spindle and movable in an axial direction, a second ratchet engaged with the first ratchet and movable in a axial direction but unrotatable, and a spring provided between the second ratchet and a partial member of a housing. An amount of movement of the spindle in the axial direction is regulated, so that the pressing force is too excessive, the restoring force of the spring urging the second ratchet is controlled to maintain a state...

A concrete drill for a rotary and percussively driven hand tool machine with a cutting part (1) and a striking part (2) that is axially and limited displaceable relative to the cutting part (1). Each of the cutting part (1) and the striking part (2) have a respective facial surface work area for machining a bore hole surface. The respective facial surface work area of the cutting part (1) and the striking part (2) radially overlap upon rotation of the concrete drill.