The disclosure concerns a system for hole drilling in an object (400) comprising a core drilling machine (100), a core drill bit (200) and a reaction bar (300) arranged for transmitting rotating reaction forces from the core drilling machine (100) to the object (400), where the core drill bit (200) is connected to the core drilling machine (100) and the core drilling machine (100) is equipped with a power source (108) in order to apply a rotating force to the core drill bit (200), and where the core drill bit (200) has an axially extending tubular shaft (202) with an inner envelop surface (203) defining an inner periphery (204) of the core drill bit (200), wherein the reaction bar (300) is non-rotatably connected to the core drilling machine (100) and arranged inside the inner periphery (204) of the axially extending tubular shaft (202) of the core drill bit (200). The disclosure further concerns a core drill bit (200) and a core drilling machine (100) for hole drilling in an object (400) and a method for hole drilling in an object (400) with a core drilling machine (100), a core drill bit (200) and a reaction bar (300) arranged for transmitting rotating reaction forces from the core drilling machine (100) to the object (400).

A robotic drilling apparatus is described which has been adapted for drilling holes in ceilings and walls on a construction site. The apparatus (100) comprises a robotic arm (110) mounted to a substructure (112), the substructure comprising a lifting mechanism arranged to lift the robotic arm to a working position, wherein the robotic arm has a base end (110a) and a movable end (110b), the base end being mounted to an upper surface (114) of the lifting mechanism and the movable end being capable of movement with respect to the base end in a three dimensional space, wherein the robotic drilling apparatus further comprises a mount (120) provided on the movable end for holding a drilling device (122) and a control unit (134) for controlling the operation of the robotic arm. The lifting mechanism preferably comprises a scissor-jack lifting platform. The robotic arm (110) and any support structure (134) for the robotic arm weighs less than 43 kg, and preferably individually weigh less than 23 kg.

A drilling tool, in particular a rock drilling tool, for a portable machine tool, includes an axis of rotation, at least one spiral path, and at least one wear surface transition. The at least one spiral path is coiled about the axis of rotation along the axis of rotation and includes at least one wear surface having at least one bandwidth. There is a change in the at least one bandwidth of the at least one wear surface at a position of the at least one wear surface transition.

A control method for the use of a core drilling system including a core drill and a feed device for driving the core drill along a machine holding device, including the following method steps:determining the end of a core drilling operation on the basis of reaching a predetermined threshold value for at least one corresponding predefined drilling parameter; andselecting a reversing mode for retracting a drilling tool out of a borehole at a reversing rotational speed which corresponds to a multiple of a predetermined tapping rotational speed of the drilling tool at the beginning of the core drilling operation. A feed device, a core drill, as well as a core drilling are also provided.

A control method for a core drill and a feed device for driving the core drill along a machine holding device, including the method steps: moving the core drill in a first direction; detecting the surface position of a material based on reaching a threshold value for at least one feed device parameter as a first reference value; moving the core drill in a second direction; operating the core drill in a tapping mode; moving the core drill in the first direction; detecting the surface position of a material based on reaching a threshold value for at least one corresponding drilling parameter as a second reference value; activating a water supply; and activating a regulating and control unit for adapting at least one drilling parameter as a function of at least one parameter of the feed device. A feed device for driving a core drill along a machine holding device for the use of the method, a core drill for the use of the method, as well as a core drilling system including a core drill and a feed device for driving the core drill along a machine holding device for the use of the method.

An apparatus for drilling a manhole includes a drill comprising a first motor and a drill bit. A rail extends longitudinally away from an exterior surface of the manhole. A carriage is movably engaged with the rail and is coupled to the drill. A mounting device supports the rail on an exterior of the manhole. The mounting device comprises features to transfer axial loading on the drill bit to the manhole. A method for drilling an opening in a manhole includes suspending a drill from a rail coupled to an exterior of the manhole. The rail extends laterally outwardly from the manhole. A drill bit forming part of the drill is rotated while moving the drill longitudinally along the rail toward the manhole. Axial reactive force generated by the drill is transferred to the manhole.

A method for detecting whether a slip clutch release event has taken place in a power tool includes determining a first speed of a gear device by a first sensor, determining a second speed of a motor by a second sensor, and determining a current value by a third sensor. The method further includes determining a state of the power tool by using the first and second speeds and the current value, determining a state of the gear device in dependence on the current value by a control device, ascertaining a state of activity of the slip clutch in dependence on the first and second speeds by the control device, and ascertaining by the control device by a combination of the state of the gear device and the state of activity of the slip clutch whether the slip clutch release event has taken place.

A one-piece cutting head for a drill bit includes a main cutting edge that extends between radial extremities of the cutting head. The main cutting edge is disposed between main rake surfaces and main relief surfaces. Each main rake surface includes one or more rake facets, and each main relief surface includes one or more relief facets. Adjacent rake facets and relief facets define a primary transverse edge therebetween that extends away from the main cutting edge. The cutting head further includes a plurality of side cutters that are transverse to the main cutting edge and that propagate from the primary transverse edge to a radial extremity of the cutting head. Each side cutter includes a side cutting edge between a side cutting rake facet and a side cutting relief facet.

A drill bit has, along a drill bit axis, a drilling head, a multi-start helix made of two or more helical coils, and an insertion end. The helix has a helix slope and a pitch in a delivery region. In an outlet region of the helix, the outlet region being directed towards the insertion end, the helical coils merge continuously, within a first portion, from an orientation in alignment with the helix slope into an orientation parallel to the drill bit axis. A length of the first portion is at least one quarter of the pitch of the delivery region. The helical coils, in a second portion, are oriented parallel to the drill bit axis.

A drive shaft for a machine tool is connectable to a drilling tool. The drive shaft contains a cavity extending substantially over the entire length of the drive shaft and along the axis of rotation where the cavity contains an inflow opening through which water can be fed along the drive shaft into the drilling tool. An insert device is provided in the cavity, through which, to cool the drive shaft, the water is guided first in a first direction and then in a second direction where the insert device contains a first curved guide element and a second curved guide element for separating the water which is guided in the first direction from the water which is guided in the second direction. The cross-sectional area of the first curved guide element is designed point-symmetrically about a center longitudinal axis to the cross-sectional area of the second curved guide element.