Abstract: A method for operating a power tool is provided. The power tool has a tool, in particular a drill bit, and a motor, while the motor is a brushless electric motor. In the power tool there is implemented a rotational speed graduation of an electronic form, with which a circumferential speed at the tool of the power tool can be kept essentially constant, while a rotational speed spread DELTA_n of greater than 2 is achieved by the design, dimensioning and/or control of the motor. Also provided is a tool device, for example a core drilling device, with which the proposed method can be carried out. An essential advantage of the invention is that the rotational speed spread DELTA_n of greater than 2 is achieved without a mechanical transmission on the power tool. Instead, a rotational speed graduation of an electronic form is used in the present invention.

Abstract: A method for determining a recommendation of a gear to be engaged for a core drill. In the method, it is possible to use for example a drop in a rotational speed of a core bit of the core drill in the event of sudden deactivation of the motor of the core drill in order to determine the diameter of the core bit. Alternatively, the diameter of the core bit can be determined when the drill is started up or turned on. The diameter of the core bit is then used as the basis for the recommendation of the gear to be engaged. In a second aspect, the invention relates to a core drill with which the method can be carried out.

Abstract: A power tool having air cooling for the components of the power tool. Here, the power tool includes exhaust openings for discharging the consumed air to the environment of the power tool. A method for protecting a user of a power tool from dust is also provided. The invention is associated with the essential advantage that air flows that exist as a result of the air cooling inside the power tool are exploited in order to blow the dust that accrues during operation of the power tool in a spatial direction “away from the user”. In a particularly preferred configuration, the air blown out can form an air curtain as a dust shield, which protects the user effectively from dust in that the air curtain keeps the dust away from the user and their airways.

Abstract: 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.

Abstract: 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.

Abstract: A method to control a power tool, especially a core drill, including a motor as the drive for the power tool, a control unit, a power display, a transmission having at least a first gear and a second gear, a first sensor to detect the rotational speed of at least one component of the transmission and a second sensor to detect the rotational speed of the motor. The method includes the following steps: ascertaining a first rotational speed of the at least one component of the transmission when the transmission has been put into a gear, ascertaining a first rotational speed of the motor when the transmission has been put into a gear, ascertaining the selection of the gear on the basis of a first prescribed ratio of the first rotational speed of the at least one component of the transmission and of the first rotational speed of the motor on the basis of a look-up table, and setting the limit value of the power display on the basis of the look-up table as a function of the gear that has been selected.

Abstract: 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.

Abstract: A method to control a power tool includes the following steps: ascertaining a first rotational speed of the transmission in a first gear; ascertaining a first rotational speed of the motor when the transmission has been put into a first gear; ascertaining the selection of a first gear on the basis of the ratio of the rotational speed of the transmission and the rotational speed of the motor on the basis of a look-up table; selecting the no-load state; ascertaining the selected no-load state on the basis of the ratio of the rotational speed of the transmission and the rotational speed of the motor on the basis of a look-up table; adapting the rotational speed of the motor to a second gear on the basis of a ratio of the rotational speed of the transmission and the rotational speed of the motor on the basis of a look-up table; and selecting a second gear.

Abstract: A method to control a power tool, especially a core drill, including a motor as the drive for the power tool, a control unit, a power display, a transmission having at least a first gear and a second gear, a first sensor to detect the rotational speed of at least one component of the transmission and a second sensor to detect the rotational speed of the motor. The method includes the following steps: ascertaining a first rotational speed of the at least one component of the transmission when the transmission has been put into a gear, ascertaining a first rotational speed of the motor when the transmission has been put into a gear, ascertaining the selection of the gear on the basis of a first prescribed ratio of the first rotational speed of the at least one component of the transmission and of the first rotational speed of the motor on the basis of a look-up table, and setting the limit value of the power display on the basis of the look-up table as a function of the gear that has been selected.

Abstract: A method to control a power tool includes the following steps: ascertaining a first rotational speed of the transmission in a first gear; ascertaining a first rotational speed of the motor when the transmission has been put into a first gear; ascertaining the selection of a first gear on the basis of the ratio of the rotational speed of the transmission and the rotational speed of the motor on the basis of a look-up table; selecting the no-load state; ascertaining the selected no-load state on the basis of the ratio of the rotational speed of the transmission and the rotational speed of the motor on the basis of a look-up table; adapting the rotational speed of the motor to a second gear on the basis of a ratio of the rotational speed of the transmission and the rotational speed of the motor on the basis of a look-up table; and selecting a second gear.

Abstract: The invention relates to a process and reactor for the quasi-continuous performance of a chemical reaction on the surface of a fixed reactant in a gas/solid phase reaction. In particular, the invention relates to a thermal process and a reactor for the continuous preparation of hydrogen from water vapor on the surface of a metal oxide in a gas/solid phase reaction.

Abstract: Shut-off device for at least partially blocking a fluid in a fluid line, including a blocking device which has a substantially cylindrical basic body and includes a first end and a second end, wherein the blocking device can be positioned in the fluid line and, by rotation in a direction of rotation (A) about an axis of rotation (R), can be reversibly adjusted from a blocking position, in which no fluid can flow through the blocking device, into a throughflow position, in which fluid can flow through the blocking device. The blocking device includes a first through-opening and a second-through opening, wherein the cross section of the first through-opening is smaller than the cross section of the second through-opening.

Abstract: A device system (10) for drilling a hole (26) having a center point (M) in a substrate (22), said device system including a power tool (12) with a drilling head (14) that can be attached to a drive shaft (15) and that can rotate around an axis of rotation (17), a tool stand (11) with a guide rail (23) and a guide block (24) to hold the power tool (12), a feed mechanism (13) for moving the power tool (12) along the guide rail (23), and a positioning apparatus (27) for determining the center point (M) of the hole (26) that is to be drilled, whereby the positioning apparatus (27) includes an emitter (34) to emit one or more laser beams.

Abstract: A device (3) for guiding a power tool (2) along an advancing direction (15), including a baseplate (9) that can be fastened to a substrate (8) by a fastener, of a guide rail section (21) that can be joined to the baseplate (9) by a joining mechanism (12) and that has a contour (18), and a guide carriage (13) for guiding the power tool (2) along the advancing direction (15), whereby the guide carriage (13) has a counter-contour (19) that can be made to engage with the contour (18), whereby a second guide rail section (22) is provided that can be joined to the first guide rail section (21) and that is configured so that it can rotate relative to the first guide rail section (21) around a rotational axis (23) that is parallel to the advancing direction (15).

Abstract: A device (3) for guiding a power tool (2) along an advancing direction (18), consisting of a baseplate (9) that can be fastened to a substrate (8) by a fastening means (10), of a guide rail (11) that can be joined to the baseplate (9) and that has a contour (21), and of a guide carriage (16) for guiding the power tool (2) along the advancing direction (18), whereby the guide carriage (16) has a counter-contours (22) that can be made to engage with the contour (21), the guide rail (11) being joined to an axis element (24) and is configured so that it can rotate relative to the baseplate (9) around a rotational axis (23) that is parallel to the advancing direction (18).

Abstract: The photoreactor comprises a tube bundle (10) made up of numerous capillary tubes (11) through which a reaction medium flows. The tubes (11) are transparent. Solar radiation or artificial radiation acts upon the reaction medium for effecting a photochemical or photobiological treatment. The inlet chamber (12) connected with the tube bundle (10) comprises a flow distributor (16) which distributes the reaction medium from the fluid inlet (15) to the tubes (11). The flow distributor (16) allows for a smaller volume of the inlet chamber (12). The reactor volume, which is not irradiated, is thus reduced, and the efficiency of the rector is enhanced.

Abstract: A power tool stand includes a guide carriage (4), and a tool coupling (1) for a portable power tool (3) and including a carriage coupling member (1a) provided on the guide carriage (4), having a clamping surface (5a), two hooks (7a, 7b) spaced from each other along the clamping surface (5a) with at least the first hook (7a) being displaceable along the clamping surface (1a), and connectable with a tool coupling member (1b) for the power tool (3) and having a clamping surface (5b the tool coupling member (1b) having two free-lying, arranged at least partially circumferentially, bolts (6) which can be hanged behind the two associated hooks (7a, 7b) of the carriage coupling member (1a).

Abstract: A device (3) for guiding a power tool (2) along an advancing direction (18), consisting of a baseplate (9) that can be fastened to a substrate (8) by a fastening means (10), of a guide rail (11) that can be joined to the baseplate (9) and that has a contour (21), and of a guide carriage (16) for guiding the power tool (2) along the advancing direction (18), whereby the guide carriage (16) has a counter-contours (22) that can be made to engage with the contour (21), the guide rail (11) being joined to an axis element (24) and is configured so that it can rotate relative to the baseplate (9) around a rotational axis (23) that is parallel to the advancing direction (18).

Abstract: A device (3) for guiding a power tool (2) along an advancing direction (15), including a baseplate (9) that can be fastened to a substrate (8) by a fastener, of a guide rail section (21) that can be joined to the baseplate (9) by a joining mechanism (12) and that has a contour (18), and a guide carriage (13) for guiding the power tool (2) along the advancing direction (15), whereby the guide carriage (13) has a counter-contour (19) that can be made to engage with the contour (18), whereby a second guide rail section (22) is provided that can be joined to the first guide rail section (21) and that is configured so that it can rotate relative to the first guide rail section (21) around a rotational axis (23) that is parallel to the advancing direction (15).

Abstract: For desalinating saline water, a solar energy collector plant comprising parabolic trough collectors is used as a heat generator. With the generated heat, a heat engine is driven by steam, wherein the heat engine drives a generator to generate electricity. The residual steam of the heat engine is used to heat a distillation device in which a first partial flow of the saline water is distilled. A second partial flow of the saline water is fed to a reverse osmosis device that is supplied with the electricity of the generator to generate pressure. After both partial flows are desalinated or partially desalinated, the two partial flows are mixed in a mixing device which thereby produces drinking water.