A light weight pneumatic screw gun. The screw gun may connect to an air compressor for installing metal roofing and wood screws in building structures. The screw gun may include a drive and include means for up to 550 feet of torque. Further, the screw gun may provide a smoother impact with a double hammer and a different shape structure than conventional screw guns. The prior art devices appear to fail to singly provide your disclosed light weight pneumatic screw gun, drive, 550 feet of torque, and double hammer in functional combination.

An inertial rotational tightening device includes: a rotationally drivable main body, an annular engagement section being disposed on a circumference of the main body; an inertial member having an engagement hole axially formed through the inertial member, the engagement hole of the inertial member being detachably engaged with the engagement section of the main body, a retaining groove being formed on a circumference of the engagement section or a hole wall of the engagement hole, an insertion groove being formed on the hole wall of the engagement hole or the circumference of the engagement section; and an elastic retainer member inlaid and buckled in the retaining groove and the insertion groove. The inertial member is detachably connected with the main body. Different inertial members with different mass can be selectively mounted on the main body to change the moment of inertia and the rotational torque of the rotational tightening device.

A liner 7 is provided with a cylinder portion 14a is formed in parallel to the rotation axis, and also a hydraulic fluid flow path 14c is formed which opens to a cylinder portion 14a to communicate with the interior of the liner serving as a high-pressure chamber and a low pressure chamber at the time of occurrence of the striking torque, and an automatic relief mechanism 14 is provided in which a cylindrical valve element 14b having a cutout portion 14b serving as a flow path for hydraulic oil formed on the outer peripheral surface portion is disposed inside the cylinder portion 14a so as to be freely rotatable.

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.

Disclosed herein is an improved hydraulic torque wrench pump (HTWP) which utilizes a combined filtration system and cooling system for filtering and cooling substantially all the oil returned to the pump including from a hydraulic torque wrench. The hydraulic torque wrench pump includes an electric motor and one or more pumping elements arranged in a protective frame. The electric motor used in association with the hydraulic pump has a high-efficiency design that includes a high power to height ratio and yields efficiency in a range of 90% to 95%. A sealed oil tank is used for storing the oil. The sealed oil tank helps in restricting one or more impurities from entering and contaminating the oil.

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 curve 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 curve 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 rotary power tool, such as an oil pulse driver, includes: a motor, a pinion rotated by the motor, planet gears that mesh with the pinion, an internal gear that meshes with the planet gears and a shaft that is rotationally driven by the planet gears and disposed frontward of the planet gears. The internal gear comprises an internal gear part and an internal gear retaining part for holding the internal gear part. An oil unit bearing is disposed frontward of the internal gear part, and the oil unit bearing is held at a front part of the internal gear retaining part.

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.

A hydraulic torque wrench and a method of determining a load exerted on a workpiece by a hydraulic torque wrench. The wrench may generally include a housing; a drive element for engaging the workpiece; a drive actuator for transmitting a torque to the drive element; and a gauge coupled to at least one of the housing and the drive actuator, the gauge being configured to detect a characteristic indicative of a torque exerted by the drive element to the workpiece. The wrench may include a sensor configured to detect rotation of the drive element.

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.