A power tool includes a housing, a motor positioned within the housing, and an impulse assembly coupled to the motor to receive torque therefrom. The impulse assembly including a cylinder at least partially forming a chamber containing a hydraulic fluid, an anvil positioned at least partially within the chamber, and a hammer positioned at least partially within the chamber and engageable with the anvil for transferring rotational impacts to the anvil. The hammer includes a surface facing the anvil, a first through hole formed in the surface and a second through hole formed in the surface. The impulse assembly further includes a biasing member biasing the hammer towards the anvil. The flow of the hydraulic fluid through the first through hole varies as the hammer translates away from the anvil.

A hydraulic torque wrench is disclosed and includes a nut engaging portion with ratchet teeth on an external surface thereof. There is also a support member which can rotate relative to whilst retaining the nut engaging portion. A ratchet mechanism cooperates with the ratchet teeth to apply a rotational force to the nut engaging portion as a result of the pushing force from a hydraulic ram. Side plate cover a junction between the nut engaging portion and the support member with the side plates having a noncircular aperture through which a nut and bolt can extend when the wrench is in use.

A hydraulic torque wrench is disclosed and includes a nut engaging portion with ratchet teeth on an external surface thereof. There is also a support member which can rotate relative to whilst retaining the nut engaging portion. A ratchet mechanism cooperates with the ratchet teeth to apply a rotational force to the nut engaging portion as a result of the pushing force from a hydraulic ram. Side plate cover a junction between the nut engaging portion and the support member with the side plates having a noncircular aperture through which a nut and bolt can extend when the wrench is in use.

A torque control method and apparatus for bolt tightening within predetermined rounds are provided. The method includes the following steps: connecting a torque control apparatus between an air supply system and a torque tool; generating a plurality of flow sets by the torque control apparatus according to the maximum air consumption of the torque tool under loading; obtaining the highest and lowest working air pressures and the corresponding maximum and minimum torque values according to each flow set, thereby constructing a relation curve between a plurality of working air pressure values and torque values; and obtaining the maximum controlling range under a working air pressure condition that the torque tool can be normally operated according to a relation curve between a plurality of working air pressures and torque values.

A method of torque control and a torque control apparatus for a pneumatic torque tool are provided. The method includes: connecting a torque control apparatus between an air supply system and a pneumatic torque tool; under predetermined working and control conditions, driving the pneumatic torque tool at the first and second working air pressures to calibrate output torque, and to obtain maximum and minimum torque values; constructing correspondence relationship between air pressure and torque value based on the first and second working air pressures and the maximum and minimum torque values obtained; entering any target torque value ranging from minimum torque value to maximum torque value of the correspondence relationship to obtain a corresponding working air pressure value and drive the pneumatic torque tool; and verifying whether all working and control conditions are controlled within a predetermined range of variation to control the output torque.

A power tool includes a housing defining a grip portion, a motor having a motor drive shaft, a drive assembly coupled to the motor drive shaft and driven by the motor, an output assembly coupled to the drive assembly and having an output member that receives torque from the drive assembly, causing the output member to rotate about an axis, and a transducer assembly disposed between the grip portion and the output assembly to measure the amount of torque applied through the output member, when the motor is deactivated, in response to the power tool being manually rotated about the axis.

A method and a device for detecting the oil level in a hydraulic pulse unit at an impulse type power wrench, wherein the pulse unit comprises an oil filled pulse chamber, a motor driven inertia drive member, and a kinetic energy receiving member connected to an output shaft and intermittently coupled to the inertia drive member via an oil cushion to receive kinetic energy from the inertia drive member during repeated energy transfer phases. The rotation speed of the inertia drive member is measured both at the start of a pulse generating phase and at the end of that phase, wherein the two measured speeds are compared to each other, and when the speed at the end of the pulse generating phase exceeds the speed at the end of that phase by a certain percentage a faulty signal is emitted indicating a too low oil level in the pulse unit.

A method detects whether a fastener is already tightened using a tightening tool with a pulse mechanism. The method includes placing the tightening tool on the fastener, and accelerating rotational parts of the tightening tool. The rotational speed of the rotational parts is limited to a first rotational threshold value in revolutions per minute during an initial tightening phase, the first rotational threshold value being set to be in a range of 20% to 80% of a second rotational threshold value in revolutions per minute needed in a secondary tightening phase to provide a target fastening value for the fastener. And it is detected whether a pulse occurs during the initial tightening phase, the initial tightening phase being measured from a moment when the rotational parts are accelerated.

A pneumatic control device includes a base seat unit, a cylinder unit and a time-delay unit. The cylinder unit is mounted the base seat unit, and is able to drive rotational movement. The time-delay unit is mounted to the base seat unit, and includes sequentially interconnected delay switch, flow-limiting valve, pressure accumulator and a control valve. The delay switch is operable to move between an action position whereat the cylinder unit drives the rotational movement, and a non-action position. When the delay switch is moved to the non-action position, the cylinder unit keeps driving the rotational movement for a period of time and then stops.

A power tool includes a housing, a motor positioned within the housing, and an impulse assembly coupled to the motor to receive torque therefrom. The impulse assembly includes a cylinder at least partially forming a chamber containing a hydraulic fluid, an anvil positioned at least partially within the chamber, and a hammer positioned at least partially within the chamber. The hammer includes a first side facing the anvil and a second side opposite the first side. The impulse assembly further includes a biasing member biasing the hammer towards the anvil, and a valve movable between a first position that permits a first fluid flow rate of the hydraulic fluid in the chamber from the second side to the first side, and a second position that permits a second fluid flow rate of the hydraulic fluid in the chamber from the first side to the second side.