A tool drive with spindle shaft for a chip-forming machining includes at least one electromagnetic axial actuator and a control and/or regulation apparatus for the operation of the axial actuator for changing the position of the spindle shaft along the longitudinal axis, wherein the control and/or regulation apparatus is designed to drive the axial actuator for the generation of microvibration movement of the spindle shaft, independently of and superimposable on a feed movement, in order to affect the chip size and chip shape of the removed material, wherein at least one axial magnetic bearing and/or one linear motor is provided as at least part of the axial actuator, wherein the regulation and/or control apparatus includes a memory unit and/or a function generation unit, and is configured to specify setpoint values of the oscillation curve of the microvibration movement depending on geometrical and or physical data of the workpiece and/or process variables that are measured or determined indirectly and/or control inputs, so that the control and/or regulation apparatus is configured to adjust an axial microvibration movement of the spindle shaft, independently of and superimposed on a feed movement, in such a way as to affect the chip size and chip shape of the removed material created when drilling.

There is provided a drilling device for drilling a sheet having conical portions, including a tool-holder plate provided with a plurality of rotary drilling spindles with drill bits oriented according to drilling directions parallel to a mean drilling direction, said drilling spindles being distributed in columns configured to be arranged according to an axial direction and in rows configured to be arranged according to a transverse direction at right angles to the axial direction, the device including at least two rows of spindles and at least two columns of spindles, wherein a center-to-center distance between two spindles of a row is different from a center-to-center distance between two spindles of another row.

This accessory, for a hand held drill, turns the drill into a portable drill press. To use this portable drill press, place the drill bit where you want it. Lean the drill forward until the base slides under the metal your drilling. The base is a lever and the drill and bit swings off it. The base holds the drill in place at a angle. When the drill is pulled straight, everything tightens up. The metal and the drill bit are pushed together with leverage. Turn the drill on and drill the hole by just holding the drill straight. This portable drill press is faster and easier to use, than drilling by hand.

An example method includes performing a machining operation by providing linear movement of a tool along a feed axis relative to a workpiece while superimposing oscillation of the tool onto the feed axis and providing rotation of the tool relative to the workpiece. During an optimization mode, the machining operation is performed on a first workpiece portion while providing the linear movement at an initial feed velocity, and sequentially superimposing the oscillating at a plurality of different frequencies. An optimal oscillation frequency is determined from the plurality of different frequencies which causes the tool to apply less force to the first workpiece portion at the initial feed velocity than others of the frequencies. During a run mode, the machining operation is performed on a second workpiece portion having a same composition as the first workpiece portion while superimposing the oscillation at the optimal oscillation frequency.

A tool drive with spindle shaft for a chip-forming machining includes at least one electromagnetic axial actuator and a control and/or regulation apparatus for the operation of the axial actuator for changing the position of the spindle shaft along the longitudinal axis. The control and/or regulation apparatus is designed to drive the axial actuator for the generation of microvibration movement of the spindle shaft, independently of and superimposable on a feed movement, in order to affect the chip size and chip shape of the removed material. At least one axial magnetic bearing and/or one linear motor is provided as at least part of the axial actuator, hi an operating method for an above-mentioned tool drive with a spindle shaft and an axial magnetic bearing is proposed, wherein an adjustable axial microvibration movement of the spindle shaft is superimposed through at least one electromagnetic axial actuator, independently of a feed, in order to influence the chip size and chip shape of the material removed from holes.

A handheld machining device (1), particularly for drilling, having a mechanism includes: a first mounting (20), on which a tool holder (2), and a motor (3, 4) arranged to rotate the tool holder (2), are mounted; a second mounting (30); and an element (40) for translatably guiding, between the first mounting (20) and the second mounting (30), a linear actuator (5) enabling the first mounting (20) to be spaced apart from the second mounting (30), and the first mounting (20) to be brought toward the second mounting (30). The motor (3, 4) is electric, and the rotor (4) of the first motor (3, 4) is directly mounted onto the tool holder (2) and is rigidly connected thereto.

A rebar hole doweling cart to construct or repair sidewalks, driveways, roadways, curbs, floors and the like. The cart has a frame with wheels, an elongated upwardly extending riser with a handle, and a nose plate that pivotally supports a drill mounting assembly near the ground. The mounting assembly holds an electric hammer drill and its bit in an aimed direction. The cart is rolled forward to tap a hole in a concrete slab and place the bit in a set aimed direction. The cart handle is then pushed forward to rotate the nose plate down into gripping engagement with the ground to advance the drill bit forward to form the rebar hole in the slab. During this forward handle rotation, the drill mounting assembly simultaneously counter-rotates (pitch pivotal movement) relative to the nose plate to maintain the drill bit in its set aimed direction.

The invention relates to a drilling device for drilling a sheet having conical portions, comprising a tool-holder plate provided with a plurality of rotary drilling spindles with drill bits oriented according to drilling directions parallel to a mean drilling direction, said drilling spindles being distributed, on the one hand, in columns intended to be arranged according to an axial direction and, on the other hand, in rows intended to be arranged according to a transverse direction at right angles to the axial direction, the device comprising at least two rows of spindles and at least two columns of spindles. The center-to-center distance between two spindles of a row is different from the center-to-center distance between two spindles of another row.

A handheld machining device (1), particularly for drilling, having a mechanism includes: a first mounting (20), on which a tool holder (2), and a motor (3, 4) arranged to rotate the tool holder (2), are mounted; a second mounting (30); and an element (40) for translatably guiding, between the first mounting (20) and the second mounting (30), a linear actuator (5) enabling the first mounting (20) to be spaced apart from the second mounting (30), and the first mounting (20) to be brought toward the second mounting (30). The motor (3, 4) is electric, and the rotor (4) of the first motor (3, 4) is directly mounted onto the tool holder (2) and is rigidly connected thereto.

The present invention is a rebar hole doweling cart that pivotally holds an electric hammer drill near the ground to tap a hole and place the bit in a set aimed direction, and grips engages the ground to produce a manually-generated leveraged pushing force to drill rebar or dowel holes into a slab of concrete to construct or repair sidewalks, driveways, roadways, curbs, floors and the like. The cart has a frame, wheels, an elongated handle, a nose plate and a drill mounting assembly. The wheels position the cart and drill in front of the concrete slab. The elongated, upwardly extending handle is manually pushed or stroked forward to rotate the nose plate into gripping engagement with the ground and advance the drill bit forward. The drill mounting assembly simultaneously counter-rotates during the stroke to maintain the drill bit in its set aimed direction as the bit advances into the slab to form the hole.