Abstract: A power tool including a motor and a pulse unit intermittently driving an output shaft, wherein the pulse unit includes a cylinder with an inner cavity arranged to withhold a hydraulic fluid, and an anvil located inside the inner cavity, the anvil being connected to the output shaft, wherein: at least one recess is arranged inside the inner cavity wherein at least one magnet is provided inside the recess; and the at least one recess is deeper than the at least one magnet such that a pocket is formed in the recess outside the magnet.

Abstract: A pneumatic impulse wrench includes a housing with a motor powered impulse unit, a pressure air inlet passage, an exhaust air outlet passage located in the housing and connected to the motor, and a motor power controlling valve mechanism located in the exhaust air outlet passage for automatic control of the exhaust air flow from the motor. A control pressure passage extends between the air inlet passage and the valve mechanism for communicating actual air inlet pressure to the valve mechanism. An operating mode shifting valve is provided in the housing and which is shiftable between an open position in which communication is allowed through the control pressure passage in an automatic valve mechanism operating mode, and a closed position in which communication through the control pressure passage is blocked in a manual valve mechanism operating mode.

Abstract: A hydraulic torque impulse generator includes a drive cylinder with a hydraulic fluid chamber, an output shaft with an impulse receiving portion connected to a radially movable seal element and intermittently dividing the hydraulic fluid chamber into high and low pressure compartments, and cam profiles which can displace the seal element from an idling position to a high pressure pulse generating position. A by-pass passage communicates fluid between the high and low pressure compartments, and a valve element movable between closed and open positions controls the fluid flow. The valve element is closed during pressure build-up in the high pressure compartment and opens when a high pressure pulse is completed, and is part of a control spindle coupled to the drive cylinder. The control spindle rotates through an angular play by inherent kinetic energy at an abrupt stop of the drive cylinder at the generation of each high pressure pulse.

Abstract: A pneumatic impulse wrench includes a housing with a motor powered impulse unit, a pressure air inlet passage, an exhaust air outlet passage located in the housing and connected to the motor, and a motor power controlling valve mechanism located in the exhaust air outlet passage for automatic control of the exhaust air flow from the motor. A control pressure passage extends between the air inlet passage and the valve mechanism for communicating actual air inlet pressure to the valve mechanism. An operating mode shifting valve is provided in the housing and which is shiftable between an open position in which communication is allowed through the control pressure passage in an automatic valve mechanism operating mode, and a closed position in which communication through the control pressure passage is blocked in a manual valve mechanism operating mode.

Abstract: A pneumatic impulse wrench includes a motor, a housing with a pressure air inlet passage, an exhaust air outlet passage, and an air flow control valve provided in the exhaust air outlet passage and including a valve element shiftable between an exhaust air flow restricting position and an exhaust air flow non-restricting position. A rigid contact member is provided to positively define the exhaust air flow restricting position of the valve element, and a bypass passage of a well-defined flow area is provided to let through a limited exhaust air flow as the valve element occupies the flow restricting position in engagement with the contact member.

Abstract: A pneumatic torque impulse delivering power tool with an automatic power shut-off mechanism including: a pneumatic motor, a drive member rotatable by the pneumatic motor, an air supply channel, with a shut-off valve, for providing pressurized air, and a valve control device that can shut the shut-off valve and stop the air flow when the drive member is exposed to a retardation magnitude above a certain threshold level. The valve control device includes: an inertia responsive member rotatable with the drive member between initial and shut-off positions in which the shut-off valve cannot and can close, respectively, and an air damped movement restrictor which can counteract a movement of the inertia responsive member towards its shut-off position such that the shut-off valve is shut when the drive member is exposed to a retardation magnitude above a certain threshold level corresponding to a dampening force of the air damped movement restrictor.

Abstract: A power tool including a motor and a pulse unit intermittently driving an output shaft, wherein the pulse unit includes a cylinder with an inner cavity arranged to withhold a hydraulic fluid, and an anvil located inside the inner cavity, the anvil being connected to the output shaft, wherein: at least one recess is arranged inside the inner cavity wherein at least one magnet is provided inside the recess; and the at least one recess is deeper than the at least one magnet such that a pocket is formed in the recess outside the magnet.

Abstract: A hydraulic torque impulse generator includes a drive cylinder with a hydraulic fluid chamber, an output shaft with an impulse receiving portion connected to a radially movable seal element and intermittently dividing the hydraulic fluid chamber into high and low pressure compartments, and cam profiles which can displace the seal element from an idling position to a high pressure pulse generating position. A by-pass passage communicates fluid between the high and low pressure compartments, and a valve element movable between closed and open positions controls the fluid flow. The valve element is closed during pressure build-up in the high pressure compartment and opens when a high pressure pulse is completed, and is part of a control spindle coupled to the drive cylinder. The control spindle rotates through an angular play by inherent kinetic energy at an abrupt stop of the drive cylinder at the generation of each high pressure pulse.

Abstract: A power wrench has a rotation motor, and a hydraulic pulse unit. The pulse unit includes an inertia drive unit connected to the motor. The inertia drive unit includes an oil chamber with an impulse generating mechanism, and an output spindle extending into the oil chamber to receive torque impulses. The inertia drive unit has a cylindrical member defining the oil chamber, a rear end wall, and an air separator element co-rotating with the wall and having a substantially axially facing surface which together with a congruent surface on the rear end wall forms oil passages in the form of a clearance gap through which oil mixed with air is circulated between one or more oil inlet openings, past one or more air outlet openings, to one or more oil outlet openings. Air is extracted from the oil and is gathered in a centrally located air collecting chamber.

Abstract: A power wrench has a rotation motor, and a hydraulic pulse unit. The pulse unit includes an inertia drive unit connected to the motor. The inertia drive unit includes an oil chamber with an impulse generating mechanism, and an output spindle extending into the oil chamber to receive torque impulses. The inertia drive unit has a cylindrical member defining the oil chamber, a rear end wall, and an air separator element co-rotating with the wall and having a substantially axially facing surface which together with a congruent surface on the rear end wall forms oil passages in the form of a clearance gap through which oil mixed with air is circulated between one or more oil inlet openings, past one or more air outlet openings, to one or more oil outlet openings. Air is extracted from the oil and is gathered in a centrally located air collecting chamber.

Abstract: A power tool comprises a housing (10) with a cylindrical outer surface (11), a rotation motor, and a power train including a reverse gearing (14, 24) with a first planetary gearing (14) for “forward” operation and a second planetary gearing (24) for “reverse” operation, and a ring gear mechanism (19, 26, 40) for establishing a reaction torque support relative to the housing (10) by coupling either one of the first planetary gearing (14) and the second planetary gearing (24) to the housing (10) to thereby shift the power transmission from a “forward” operation mode to a “reverse” operation mode, wherein the gear ring mechanism comprises a separate rotatable ring gear (19, 26) for each planetary gearing (14, 24) and an axially displaceable coupling ring (40) for alternative engagement with the ring gears (19, 26).

Abstract: A backflow preventing check valve for use in a fan unit in a forced air cooling system includes a generally rectangular frame, a plurality of adjacent parallel pivot axes mounted in the frame, and a plurality of adjacent vanes that pivot around the axes between open and closed positions. The axes extend generally transverse to the direction of fluid flow through the valve, and each axis is offset from the center of gravity of its associated vane so that fluid flowing through the valve in an allowed direction moves the vanes toward the open position, and fluid flowing in a blocked direction moves the vanes toward the closed position. The axes are inclined at an angle (?) measured from a vertical reference, thereby causing the vanes to be urged by gravity to pivot towards the closed position.