Abstract: According to an aspect of the present invention, there is provided a rotary striking tool, including: a motor; an impact unit having a driving part being driven by the motor and an output part; a tip-tool side output shaft that is coupled to the output part; an impact detection unit that detects an impact generated at the impact unit; and a control unit programmed to: control the impact unit to perform a confirmation striking when the impact detected by the impact detection unit reaches a prescribed value, detect a rotation angle of the output shaft at the confirmation striking, determine whether a fastening operation is completed when the detected rotation angle is equal to or smaller than a predetermined angle, and continue the fastening operation when the detected rotation angle is larger than the predetermined angle.

Abstract: An improved method is provided for operating a power tool. The method includes receiving an input control variable from an input unit; determining a derivative of the input control variable; selecting one of a plurality of control profiles based on the control input variable and the derivative, each control profile correlating the control input variable of the input unit to a rotational speed at which to drive the output shaft; and driving the output shaft at a rotational speed in accordance with the selected control profile.

Abstract: A driving tool having a driver, a power source, a sensor and a controller. The power source selectively provides an input to the driver to cause the driver to translate along an axis. The sensor senses a condition in the power source that is indicative of a level of kinetic energy of an element in the power source and generates a sensor signal in response thereto. The controller is coupled to the power source and the sensor and is responsive to the sensor signal for deactivating the power source to inhibit the power source from providing the input to the driver when the level of kinetic energy of the element in the power source is below a predetermined threshold. A method for operating a driving tool is also provided.

Abstract: A drive unit has an output subject to changing loads, where the drive unit consists of fixed and moving parts connected to a power source. The output of the drive unit is controlled in cycles, and for ascertaining the load in a given cycle, the time period required for changing the position of the moving part of the drive unit, or for changing the position of the moving part of the equipment in mechanical contact with the moving part of the drive unit, from one predefined position to another predefined position is measured, whereby the input required in the next cycle is determined according to the time period ascertained in at least one preceding cycle. Where the drive unit is an electric motor, the input required in given cycle is also determined according to electric resistance of the electric motor ascertained in at least one preceding cycle.

Abstract: An extension tooling apparatus can include a delivery portion and a control portion. The delivery portion can include a base element mountable to a fixed surface, an arm pivotably coupled to the base element, and a tool attachment coupled to a tool end of the arm. The control portion can include a shank, a tip member joined to a tip end of the shank, and a collar adjacent a distal end of the tip member. The collar can support the tool attachment of the delivery portion so that positioning of the tool attachment is controllable by movement of the shank. The extension tooling apparatus can be useful for manipulating nuts, bolts, and other hardware from a distance.

Abstract: A power-operated hand-held power tool, in particular a power tool comprising an oscillation drive for driving a tool in an oscillating manner, comprising at least one sensor for detecting vibrations and comprising a controller which is coupled to the at least one sensor to control at least one operating parameter of the The power tool according to an output signal of the at least one sensor, the The power tool being configured to receive different tools, and the controller being configured to evaluate the output signal of the at least one sensor and preferably to compare it with stored characteristic values for the vibrations of different tools so as to control at least one operating parameter of the The power tool according to said comparison, is specified.

Abstract: A rotation speed control device for air tools and the method thereof are disclosed. A shell base is disposed with a forward air inlet and a reverse air inlet. A back cover is connected to one side of the shell base. The back cover has a forward flow path in communications with the forward air inlet and a reverse flow path in communications with the reverse air inlet. The forward flow path has a rotation space whose one side has a pressure release hole in communications with the ambient space. A rotation speed control element having a stopping part that can close the pressure release hole is disposed in the rotation speed. The rotation speed control element rotates to control the aperture size of the pressure release hole, thereby adjusting the airflow entering the forward flow path.

Abstract: A pneumatically striking hand-held power tool is controlled by the following steps. An acceleration (a) along a striking axis (8) of the hand-held power tool (1) is detected. A driving power is reduced if the detected acceleration (a) is greater than a threshold value (A), the threshold value (A) being selected to be greater than maximum acceleration values (a1, a2) that occur on a workpiece during the striking operation of the hand-held power tool (1).

Abstract: A hand-held power tool, in particular to a screwing device, includes a control device for controlling and/or regulating the tool movement of a tool holder and/or of a tool. The hand-held power tool has an interface for communicating with an external adjustment device. The interface is configured to be connected to the control device in such a way that signals may be transmitted for the parameterization of at least one tool movement sequence. The tool movement sequence includes a plurality of sequentially-progressing tool movements. A method for parameterizing at least one tool movement sequence of a hand-held power tool includes parameterizing the at least one tool movement sequence with a separate setting device in a remote-controlled manner via an interface of the hand-held power.

Abstract: The present invention is an articulating hand power tool with a main housing having a longitudinal axis, a head portion rotatably engaged with the main housing for placement at a plurality of angles with respect to the longitudinal axis of the main housing, an integrated circuit board located within the main housing and at least one controller accessible from outside of the main housing for controlling the integrated circuit board.

Abstract: A surgical cutting and fastening instrument that includes an elongate channel that is attached to a handle assembly by an elongate shaft assembly. The elongate channel is configured to receive a cartridge and has a pivotally translatable anvil attached thereto and a knife bar supported therein. The anvil may be selectively opened and closed by manipulating a closure trigger supported by the handle assembly. The knife bar may be distally advanced through the elongate channel by actuating a firing trigger that cooperates with a reversible rotary drive supported by the handle assembly. The knife bar may also be retracted to its starting position by actuating the firing trigger after the reversible rotary drive has been shifted to a retraction orientation.

Abstract: A drop hammer for driving a pile comprising a ram member supported within a housing chamber for movement relative to the housing member between the lower position and the upper position and a lifting system for moving the ram member from the lower position to the upper position. When the lifting system raises the ram member above a preload position, ambient air substantially freely flows into and out of the housing chamber through a vent port. When the ram member falls below the preload position, fluid is prevented from flowing through the vent port such that ambient air within a preload chamber portion of the housing chamber compresses to create a preload force that is transmitted to the pile. When the ram member moves into the lower position, an impact force generated by the ram member is transmitted to the pile.

Abstract: A power tool includes an electric motor including a rotor and a stator, a torque sensor for measuring the torque value during tightening of rotatable fastening elements, and an operation control unit, integrated in or in communication with the power tool. The power tool has a device for preventing rotation of the rotor. A method for tightening rotatable fastening elements by use of the power tool is also disclosed.

Abstract: A diesel hammer comprises a housing, an anvil, and a release valve. A combustion chamber is formed within the housing below the anvil. The release valve operates in a closed configuration in which fluid is substantially prevented from flowing out of the combustion chamber and an open configuration in which fluid is allowed to flow out of the combustion chamber through the release valve. The diesel hammer operates in a cycle mode in which the release valve is in the closed configuration and, when the anvil moves from an upper position to a lower position, the anvil compresses fluids within the combustion chamber and an interrupt mode in which the release valve is in the open configuration and, when the anvil moves from the upper position to the lower position, the anvil does not substantially compress the fluids within the combustion chamber.

Abstract: The invention relates to a fastener-setting tool with a combustion chamber (12), in which an electrically driven device (14) for generating turbulence or for flushing the combustion chamber (12) is arranged, and with an electrical energy storage device (24). In order to further simplify the operation of a fastener-setting tool, the electrical energy storage device (24) is configured for operation with non-rechargeable primary cells.

Abstract: A wrench having multiple tool interfaces is provided. The wrench includes means for manually rotating about an axis located between the proximal and distal ends using a single force in a substantially tangential direction about the axis. The means for rotation might be a curve suitable for interface with a human finger. A method of rotating a tool is also provided.

Abstract: An electric power tool is provided with: a motor; a hydraulic pressure generator driven by the motor and configured to generate a plurality of impacts in one revolution thereof; an impact angle detector configured to detect an impact angle in one impact of the hydraulic pressure generator; an electric current detector configured to detect an electric current applied to the motor; a determination unit configured to determine an impact failure based on the impact angle and the electric current detected by the impact angle detector and the electric current detector; and a rotation controller configured to decrease a rotation speed of the motor when the determination unit determines the impact failure.

Abstract: An improved method is provided for operating a power tool. The method includes receiving an input control variable from an input unit; determining a derivative of the input control variable; selecting one of a plurality of control profiles based on the control input variable and the derivative, each control profile correlating the control input variable of the input unit to a rotational speed at which to drive the output shaft; and driving the output shaft at a rotational speed in accordance with the selected control profile.

Abstract: A portable linear fastener driving tool is provided that drive staples, nails, or other linearly driven fasteners. The tool uses a gas spring principle, in which a cylinder filled with compressed gas is used to quickly force a piston through a driving stroke movement, while a driver also drives a fastener into a workpiece. The piston/driver is then moved back to its starting position by use of a rotary-to-linear lifter, and the piston again compresses the gas above the piston, thereby preparing the tool for another driving stroke. The driver has protrusions along its edges that contact the lifter, which lifts the driver during a return stroke. A pivotable latch is controlled to move into either an interfering position or a non-interfering position with respect to the driver protrusions, and acts as a safety device, by preventing the driver from making a full driving stroke at an improper time.

Abstract: A power tool includes an output shaft configured to rotate about a longitudinal axis, a motor drivably connected to the output shaft to impart rotary motions thereto, and a rotational motion sensor spatially separated from the output shaft and operable to determine the user-imparted rotational motion of the power tool with respect to the longitudinal axis. A controller is electrically connected to the rotational motion sensor and the motor. The controller determines angular velocity of the power tool about the axis, rotational displacement of the power tool about the axis, and/or a direction of the rotational displacement using input from the rotational motion sensor. The controller then controls the motor according to the angular velocity, the rotational displacement, and/or the direction of the rotational displacement.

Abstract: A method of quarrying dimensional stone and a line drilling apparatus used therein. The drilling apparatus is frameless and comprises a first boom and a second boom, between which is arranged a joint mechanism, allowing the booms to be moved relative to each other. Furthermore, in connection with the joint mechanism is arranged a stone support adaptable against the stone once the drilling apparatus is coarse-positioned in the vicinity of a drill hole line. Fine positioning of the drilling apparatus in the direction of the drill hole line is performed by joints comprised by the joint mechanism. Positioning at drill holes takes place by turning the second boom along an arched motion path and by turning the drilling unit towards the stone to be drilled.

Abstract: A torque limiting engine rotation tool for rotating a crankshaft of an engine, where the engine rotation tool is configured to be operated with a socket wrench or non-impacting tool and is configured to engage an accessory drive pulley bolt or any other bolt that causes the crankshaft to rotate, includes a socket body. The socket body has a driving portion coupled to a bolt-torquing portion with a shear pin. A receiving recess is defined by the driving portion and is configured to receive the socket wrench or non-impacting tool. A female socket recess is defined by the bolt-torquing portion and is configured to engage the bolt. The amount of torque applied by the socket wrench or non-impacting tool to the bolt is limited by the shear strength of the shear pin.

Abstract: The present invention provides methods and systems for a rotary impact device having an annular exterior surface for use with an impact wrench for providing torque to a fastener. The rotary impact device includes an input member having an input recess for receiving the anvil of the impact wrench, an output member having an output recess for receiving the fastener, and an inertia member. The inertia member is stationary and positioned on the exterior surface of the rotary impact device for increasing the torque applied to the fastener.

Abstract: A system, and a method of using a system, for controlled tool operation. The method includes providing a tool used in a force application such as a such torque application. The tool communicates with a controller which can communicate with the tool, and to a display in communication with the tool and the controller. The controller can be programmed with operational information about a tool operation. Information related to the operational information is displayed to a user during use. Service information including at least information about an amount of force applied during use is recorded and stored in the controller. Also disclosed is a computerized system for controlled tool operation which sends operational instructions to the tool before use and retrieves service information from the tool after use.

Abstract: The hand-held power tool has a tool socket to hold a tool. A motor is coupled to the tool socket in order to drive the tool socket. The motor is arranged in a housing. The housing has a holder that is provided with a mechanical lock for detachably coupling a battery pack, and with a power connection for electrically connecting the battery pack to the motor. A communication interface serves to transmit properties of the battery pack to a motor control unit. The motor control unit includes a soft start that accelerates the speed of the motor from a standstill to a target speed at a given rate, whereby the motor control unit controls the rate as a function of a property of the battery pack transmitted by the battery pack.

Abstract: A power pruner includes a housing, a motor arranged in the housing, a transmission device connected to the motor, a pair of blades and a trigger which is arranged on the housing and used to control the motor. The pair of blades include a fixed blade and a movable blade which is driven by the motor to swing back and forth. The power pruner additionally includes a stroke switch which is arranged on the housing and has at least two statuses wherein the movable blade has a first stroke when the stroke switch is in a first status and a second stroke different from the first stroke when the stroke switch is in a second status.

Abstract: A pneumatically powered pole saw is provided, the pole saw having gas actuated main valves configured for movement between first positions and second positions wherein the gas actuated main valves are located in a main valves assembly fluidly coupled to the piston chamber; and a first pilot valve is configured to send actuating gas through a conduit to the main valves assembly and a second pilot valve is configured to send actuating gas through a conduit to the main valves assembly wherein the cutting blade moves in opposite directions in response to the actuating gas of the first and second pilot valves.

Abstract: A tool discharges one battery pack and a charger simultaneously charges another battery pack to provide for continuous and circular operation of the tool. The ratio of the discharging time to the charging time is approximately 25:35.

Abstract: A combustion tool having a circuit for conserving battery power includes a battery assembly to power at least a portion of the combustion tool, a control circuit to place the combustion tool in an active mode or a low power consumption mode, and a motion sensing circuit to indicate a movement of the combustion tool and to indicate a non-movement of the combustion tool. A timer is set when a movement is detected and resets each time a new movement is sensed. If a new movement is not sensed when a predetermined amount of time has elapsed, the combustion tool enters into a low power consumption mode. The movement may be a vibration or a tilt movement. The motion sensing circuit enables the tool to be actuated without any unnecessary priming when motion is sensed and only minimal current is consumed when motion is not sensed, conserving battery power.

Abstract: An installation method for an expansion anchor is carried out by repeatedly exerting rotary-percussive strikes onto the shank (2) of the expansion anchor (1) by an impact screwdriver. The repeat rate (Ntarget) of the rotary-percussive strikes is selected as a function of the tightening torque prescribed for expanding the expansion sleeve (3) of the expansion anchor (1). The impact screwdriver stops generating rotary-percussive strikes when the detected mean rotational speed (d) of the shank falls below a threshold value (D).

Abstract: A compliant shifting mechanism can change the operation of a power tool between first and second operating conditions. The shifting mechanism can provide two distinct forces on a gear set during movement of the gear set between the two operating conditions. The shifting mechanism can provide a user with a tactile sensation of the completion of the transition between the two operating conditions without the gear set completing the full transition. A shifting mechanism can automatically complete the change between operating conditions, regardless of an alignment between the gear set and another component. The two distinct forces can be a torsional resistance force and a bending resistance force.

Abstract: A tong assembly includes a case assembly and a tong head assembly disposed in the interior of the case assembly and adapted to engage a first sucker rod. A transmission assembly engaged to a hydraulic motor and including a backup tong assembly. The backup tong assembly includes a backup tong having a first end and an oppositely disposed second end adapted to hold a second sucker rod. A load pin engaged to the second end of the backup tong and an outer casing of the transmission assembly, the load pin includes strain gages for measuring a force applied to the first end of the backup tong to output a force signal. A rotary encoder engages a shaft of the hydraulic motor and outputs a position signal when a. A controller generates an output signal based on only one of the force signal or the position signal when the force signal is greater than a predetermined value or when the position signal is within a predetermined range of values.

Abstract: A method of driving a nut on a bolt comprising using a motorized socket drive tool having an open drive socket located in a drive head portion, is provided. A support assembly having a spring loaded biasing portion configured for travel along a torque arrest path, where a torque arrest member is coupled with the spring loaded biasing portion in an operative position, is provided in a coupled arrangement with the motorized socket drive tool. The open drive socket is directed to pass over the nut and the torque arrest member is directed to engage the bolt such that the open drive socket may drive the target nut, while the torque arrest member holds the bolt from rotation. The open drive socket and torque arrest member are respectively released from the nut and the bolt after the nut reaches a predetermined destination on the bolt.

Abstract: A method controls the rotational speed limiting of an engine in a handheld work apparatus. The crankshaft of the engine drives a worktool via a clutch which engages in dependence on the motor rotational speed. Above an engaging speed of the clutch, a drive connection with the crankshaft is made and below the engaging speed, the drive connection is interrupted. A speed control unit monitors the rotational speed of the engine and includes a rotational speed lock circuit which limits the speed to a limit below the engaging speed. During the start of the engine, the lock circuit is switched on; it is switched off after the engine has been taken into operation when a deactivation signal is present, wherein the deactivation signal is generated when an operation change signal of the work apparatus is detected.

Abstract: A transmission assembly for a power tool includes a first transmission path comprising a high speed transmission path, a second transmission path comprising a low speed transmission path, a controller for one of engaging and disengaging the high speed transmission path, and a clutch for enabling the low speed transmission path to operate at a lower speed than an output of the transmission assembly when the high speed transmission path is engaged.

Abstract: The invention relates to systems and methods for providing a stake driver attachment apparatus having a planar surface that facilitates driving a stake into a penetrable medium adjacent and substantially parallel to a stationary object or surface.

Abstract: A portable linear fastener driving tool is provided that drive staples, nails, or other linearly driven fasteners. The tool uses a gas spring principle, in which a cylinder filled with compressed gas is used to quickly force a piston through a driving stroke movement, while a driver also drives a fastener into a workpiece. The piston/driver is then moved back to its starting position by use of a rotary-to-linear lifter, and the piston again compresses the gas above the piston, thereby preparing the tool for another driving stroke. The driver has protrusions along its edges that contact the lifter, which lifts the driver during a return stroke. A pivotable latch is controlled to move into either an interfering position or a non-interfering position with respect to the driver protrusions, and acts as a safety device, by preventing the driver from making a full driving stroke at an improper time.

Abstract: A method and pile-driving device for driving a support into a ground surface. The device comprises a cylinder, an anvil which closes the lower side of the cylinder at least substantially, a ram which is movable as a piston above the anvil within the cylinder, and an injection device for injecting fuel into a combustion chamber between the anvil and the ram. The device has adjusting means for adjusting the moment of fuel injection and/or the amount of fuel to be injected. The method includes: causing the ram to move downward; injecting fuel into the combustion chamber; causing the fuel to combust for driving the ram upward, in such a manner that said combustion occurs before the ram strikes the anvil, wherein the moment of fuel injection and/or the amount of fuel to be injected is/are adjusted in dependence on at least one variable.

Abstract: A power tool system includes a two-handed power tool having first and second start actuators, one for each hand of an operator. A controller prevents the power tool from initiating an operating cycle unless both actuators are turned ON to reduce the possibility of the operator's hands being disposed in a hazardous position during operation of the power tool. To discourage manual override of the dual-start-switch system, the controller prevents the power tool from initiating an additional operating cycle until both actuators have been switched OFF and then ON again. The second actuator includes a tubular sleeve that extends over part of the power tool to allow the sleeve to slide axially relative to the power tool between ON and OFF positions. Axial movement of the sleeve from its OFF position to its ON position turns ON the second start actuator.

Abstract: A pulse drilling machine (1;1?) for the generating of shock wave pulses in a tool direction (R) has an impulse piston (4;4?) with a housing (2), and a device (8) for abruptly changing fluid pressure influencing the impulse piston to achieve a force resultant on the impulse piston in the tool direction to generate a shock wave pulse in a drill string (13; 13?) which is connected to the machine, a first fluid chamber (14;3?) inside the housing which in operation is arranged to exert a pressure in the tool direction on the impulse piston. The machine has a fluid flow channel (11; 18; 19), which includes a device for damping fluid flow flowing from the first fluid chamber through the fluid flow channel obtained when influencing the impulse piston (4; 4?) in a direction opposite to the tool direction (R) by rock reflexes in the drill string during drilling.

Abstract: A portable tool, in particular a screwing tool, has a tool head for processing a workpiece, has a drive device for driving the tool head, and has a control device for controlling the drive device, at least one work parameter of the drive device being variable. The tool has a signal detecting device, at least temporarily connected to the control device for signaling purposes, for wireless reception of signals, these signals being characteristic of at least the at least one work parameter, and the control device being fashioned in such a way that it defines the at least one work parameter in reaction to a signal detected by the signal detecting device.

Abstract: A portable and battery-operated tool for machining a workpiece and to a method for replacing the rechargeable battery of the tool is disclosed. The tool has at least one drive device for driving a working head, at least one rechargeable battery for providing electrical energy, at least one control device with an operating system for controlling and/or regulating machining parameters, at least one storage device for storing machining data and at least one transmitting and receiving device for transmitting and/or receiving the machining data and also at least one substantially electrical element for storing electrical energy at least for a short time in order to make it possible to replace the rechargeable battery when the operating system is activated.

Abstract: The disclosure relates to a method for using a rechargeable battery-operated screwing system which is suitable for establishing screw connections by means of a motor-driven working spindle. The rechargeable battery-operated screwing system having communication devices for wirelessly transmitting data for defining screwing curves, which describe a screwing process, between a screwing spindle module and an evaluation module, with at least two variables which are characteristic of the screwing curve being wirelessly transmitted by means of the communication devices and at least one further variable which is relevant for the screwing curve being calculated from the transmitted data by the evaluation module.

Abstract: A pressure protection valve is provided which provides a fluid short circuit between a fluid pressure inlet of a hydraulic tool such as a hydraulic hammer and a low pressure region when the pressure at the fluid pressure inlet exceeds a first trigger pressure equal to a predetermined permissible pressure. This prevents damage to the hydraulic tool which can arise through operation at excessive fluid flow or pressure from hydraulic fluid supplied by a carrier vehicle. The pressure protection valve may maintain fluid communication between the fluid pressure inlet and the low pressure region until the pressure at the fluid pressure inlet reduces to a pressure below a predetermined second trigger pressure which is less than the first trigger pressure, to prevent further operation of the tool until the flow of fluid to the fluid pressure inlet has been stopped by an operator.

Abstract: An improved method is provided for operating a power tool. The method includes: monitoring rotational motion of the power tool about an axis using a rotational motion sensor disposed in the power tool; determining a direction of the rotational motion about the axis; and driving the output member in a direction defined by the detected rotational motion of the tool, where the output member is driven by a motor residing in the power tool. Thus, the output member is drive clockwise when the rotational motion of the tool is clockwise about the axis and the output member is drive counter-clockwise when the rotational motion of the tool is counter-clockwise about the axis.

Abstract: A fastener driving tool and method for driving fasteners into a substrate is disclosed. The tool includes a working piston that is capable of being moved abruptly translationally so as to drive a fastener, such as a stud or a nail. In order to further improve the handling and/or energy efficiency during operation of a fastener driving tool, the fastener driving tool includes an operating device that enables switching between a manual and an automatic output-power regulating mode.

Abstract: A hand tool impacting device may include, a drive shaft with an aperture, an impaler disk, and a floating pin positioned within the aperture of the drive shaft. A set of circular ramps on the outer edge of the impaler disk may interact with a stationary pin insert to translate the drive shaft and create an impacting motion. A pair of springs placed against either side of the floating pin may allow a specialized tool bit to engage or disengage the impaler disk, thereby allowing selective use of translational impacting motion, or rotational torque. An impact bit for engaging the impaler disk may include, a tool head configured to engage a work piece and a tool shaft configured to be inserted into a hollow drive shaft to engage a floating pin. According to one embodiment, the impact bit includes a number of sleeves to guide the tool head during operation.

Abstract: Provided is an actuator and method for operating an actuator. For example, the actuator may have first and second operating phases, a housing having an opening receiving pressure, a piston inside the housing for moving along inside the housing and positioned therein for creating a first chamber between one end of the piston and the housing and a second chamber between the other end of the piston and the housing, first and second ports each capable of communicating with the pressure source during a different one of the first and second phases, an extra area chamber between the piston and the housing. In the first phase the first port may be communicating with the opening for providing pressure to the first and extra area chambers. In the second phase the second port may be communicating with the opening for providing pressure to the second chamber.

Abstract: The invention relates to an electrically powered bolt setting device (1) for setting of fastening elements (3) with a spring unit (10) which acts as an intermediate energy store in order to store energy, originating from an electric drive (25), in the bolt setting device (1), and said energy can be released suddenly during a bolt setting process. In order to create an electrically powered bolt setting device which has a simple design and can be produced at low cost and/or is low in cost to operate, the spring unit (10) cooperates with a unit to adjust the interim-stored energy.

Abstract: A method for controlling a fluid operated percussive device, which inside an axially extending cylinder room (3) of a housing (2) of the percussive device includes a to and fro moveable percussive piston (1), which is adapted for performing strikes in a striking direction (A) and which includes a signal portion (4) for controlling a main valve (5), which is adapted to intermittently transmit pressure fluid to at least one driving chamber (7) for the percussive piston. An auxiliary valve (9) is controlled for transmitting fluid contact between at least one auxiliary channel means (13,14) with a channel opening in the cylinder room (3), and the main valve (5) over the signal portion (4), for switching the main valve (5) before the percussive piston, in operation, has reached at least one of said regions. The invention also concerns a percussive device and a rock drilling machine.