Abstract: An impact torque generator for a hydraulic torque wrench includes a liner, a main shaft, a first drivable blade and a second drivable blade. The liner has two sealing surfaces defined at a position of 180 degree rotational symmetry. For each of the first drivable blade and the second drivable blade, a first sealing surface of the drivable blade is configured to be in contact with one of the sealing surfaces of the liner while a second sealing surface of the drivable blade slides in contact with an inner peripheral surface of the liner so as to create a seal such that a portion of an interior of the liner is divided into a high-pressure chamber and a low-pressure chamber so as to generate impact torque on the main shaft.

Abstract: 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.

Abstract: An impact torque adjusting device of a hydraulic torque wrench enhances the precision of the magnitude of the impact torque generated, shortens the generation period of impact torques, and enhances the durability when rotating in either of two directions, that is, in normal rotation (when tightening) and in reverse rotation (when loosening). A working fluid path 11b communicates with the inside of a liner 7 serving as a high-pressure chamber H and a low-pressure chamber L when an impact torque is formed. A valve body 11d biased in a direction of releasing the working fluid path 11b is disposed in the working fluid chamber 11b. At the rear back side of the valve body 11d, an oil chamber 15e is formed to communicate with a blade insertion part 8a of a main shaft 8 by way of fluid paths 7c, 7d formed in liner lids 7a, 7b.

Abstract: An angle nut runner capable of accurately measuring a genuine tightening force includes an output shaft pivotally supported approximately perpendicular to the rotating shaft 1 of the drive source, a strain measuring mechanism for measuring a strain generated in the output shaft is disposed on the output shaft.

Abstract: An impact torque adjusting device is constructed by forming an operating fluid channel 11b communicating through the inside of a liner 7 which becomes a high-pressure chamber H and a low-pressure chamber L at the time impact torque is generated. In the operating fluid channel 11b, a valve disc 11d is urged in the direction opening the operating fluid channel 11b. Behind the valve disc 11d, an oil chamber 11e communicates with the inside of the liner 7 which becomes a high-pressure chamber H at the time impact torque is generated, so that the operating fluid channel 11b may be narrowed in proportion to the increase of the operating fluid.

Abstract: An air driver device having a simple construction, being of a compact size, and having excellent durability. The air driver device is designed to shut off a supply of compressed air to an air motor, by means of a tightening torque control mechanism and a shut-off valve mechanism, in a case where the tightening torque reaches the set torque value. The air device is designed to tighten screw members at a prescribed tightening force, wherein the tightening torque control mechanism is composed of (i) a clutch unit, (ii) a driving piston on the back face of which is formed one clutch plate, so that clutch plates of the clutch unit may move by making rotational differential motions in a case where the tightening torque reaches the set torque value, (iii) a cylinder for storing this driving piston, (iv) a check valve for operating the shut-off valve mechanism, in linkage with the driving piston through an oil charged in the cylinder, and (v) a torque control member for regulating the set torque value.

Abstract: An electric screwdriver capable of reducing the reactive force produced on the occasion of a screw tightening work, etc. The electric screwdriver is designed to transmit the rotational driving force of a first motor to the bit through a bit holder, and it includes a flywheel rotatively driven by a second motor in the direction same as the direction of rotation of the bit holder, a brake generating a reactive force in the direction offsetting the reactive force transmitted from the bit to the body casing through the bit holder, by braking the flywheel, and a brake operating mechanism for operating the brake in response to the magnitude of the reactive force transmitted from the bit to the body casing through the bit holder.

Abstract: An impulse torque generator for a hydraulic torque wrench is durable, compact in size and capable of stably generating a large impulse torque while eliminating a blade being inserted in the main shaft. A main shaft has a cam thereon positioned to be slidable in an axial direction without turning against the main shaft. Oil guide holes pass in an axial direction inside the cam. A cylinder receives the base end of the main shaft and the cam, and forms oil chambers to be filled with an operating fluid across the cam. Pins are inserted in the cam groove of the cam, provided projecting from the inner circumferential face of the cylinder. A drive shaft is to be connected to a drive source which rotatively drives the cylinder. A check valve shuts off the circulation of operating fluid between the oil chambers formed across the cam by selectively closing the oil guide holes formed in the cam, depending on the relative rotating angle between the cam and the cylinder.

Abstract: An impulse torque generator, for a hydraulic impulse torque wrench, includes a liner driven by a rotor. The liner has an inner cavity with at least two pairs of sealing surfaces around its inner peripheral surface. A main shaft extends coaxially through the liner and includes at least two projections. Also, at least two driving blades are provided for generating an impulse torque on the main shaft by abutting the projections of the main shaft.

Abstract: A pressure detecting device in a torque control wrench has a rotor to be rotated by high pressure air, an output shaft and a device for generating impulse torque with the use of oil pressure on the output shaft due to rotation of the rotor. The device has a liner rotated by the rotor rotatably mounted on the output shaft. The device forms a high pressure chamber and a low pressure chamber in the liner for the generation of impulses on the output shaft, and has a hole therein having first and second ports communicating with the high and low pressure chambers, respectively. A valve is disposed in the hole for adjustably regulating the flow of oil from the first port to the second port and for generating a shut-off signal. The valve has a valve shaft adjustably mounted in the hole, having a passage therein communicating with the high pressure chamber. The passage has an opening at an end of the valve shaft.

Abstract: An oil pressure type impulse torque generator for a wrench. Either one of both seal surfaces on the main shaft side and the liner side is made a variable type by floating in order to eliminate "burning" and wear at the seal surfaces. The seal surfaces may be formed by rollers.

Abstract: An oil pressure type pneumatic torque wrench which comprises a main shaft, a liner rotatable by a rotor with at least four seal points which are formed on the inner circumferential surface of the liner and two blades provided on the main shaft. The center of two opposing seal points on each of the shaft and liner are spaced equal distances from diametrical lines thereof so that each rotation of the liner produces one impulse.

Abstract: A clutch type torque control device characterized in that balls seated in ball receiving holes made in a main shaft are pressed against squarely planed-off surfaces made at the outer circumferential surface of a cam fitted to a driving shaft which is driven by an air driven motor through the medium of a spring and a cam ring for transmission of motive power from the cam to the main shaft and a stop pin inserted in the main shaft is engaged with a planed-off part made at the outer circumferential surface of a pilot pin slidably inserted in the cam, whereby when a torque load on the main shaft reaches a predetermined torque value the stop pin is disengaged from said planed-off part due to rotational difference between the cam and the main shaft and consequently a valve kept open through the medium of the pilot pin and a push rod is closed, resulting in the stopping of the motor.