Abstract: An impact wrench has a casing accommodating rotatable anvil and shaft, the shaft supporting a hammer having a body with longitudinally extending passages in which pins are received for axial reciprocations which pins are engaged with the anvil in one position. A driving member received in an axial passage of the hammer body is coupled to the shaft to perform rotation and axial movement, the driving member being connected to the hammer body for rotation together therewith, and cooperating with a spring for moving the pins into a position, in which they are engaged with the anvil. The longitudinally extending passages open into the axial passage of the hammer body. Each pin has a bearing surface engageable with a respective bearing surface of the driving member during movement of the pins into the other position, the bearing surface being located on a portion of each pin protruding into the axial passage of the hammer body.

Abstract: An impact wrench comprising a drive shaft, an anvil with impact cams, a striker having a flywheel mass connected to the drive shaft and impact cams connected to the flywheel mass so as to rotate therewith and move axially in relation thereto. The impact wrench includes a device designed for preventing the striker impact cams from interaction with the anvil impact cams until the striker attains a pre-set rotational speed. According to the invention, the flywheel mass and the anvil are immobile axially, whereas the striker impact cams are adapted to move axially in relation to the striker flywheel mass during striker acceleration.

Abstract: An impact wrench comprises an anvil having impact jaws, a composite hammer including a driving part coupled to an output shaft of a pneumatic motor and a driven part having impact jaws for co-operating with the impact jaws of the anvil and mounted in the driving part for a combined rotation and a relative axial movement. A diametrical slot is provided in the driving part to receive a slider having its center of gravity offset relative to the hammer axis. The anvil receives a stub shaft mounted for a combined rotation together therewith and a relative axial movement and having a spring-loaded locking member co-operating with the slider. This construction of the pneumatic impact wrench enables a greater amount of kinetic energy to be transmitted into a threaded joint with each blow so as to improve the efficiency and reduce vibrations.

Abstract: An impact wrench comprises a casing accommodating an axially immovable anvil having impact jaws, an axial bore and a counterbore in the axial bore, a composite hammer including a driving part coupled to a motor for rotation together therewith, an outer driven part having impact jaws engageable with the impact jaws of the hammer, and an inner driven part received in the counterbore of the anvil. The outer and inner driven parts of the hammer are connected to each other and to the driving part of the hammer for combined rotation therewith and being axially movable relative to the driving part of the hammer and to the anvil. The impact wrench also comprises a device for a preliminary interaction of the hammer and anvil before engagement of their impact jaws, including spring-loaded locking members. The spring-loaded locking members are mounted in the inner driven part of the hammer in an axial space between the impact jaws of the hammer and anvil.

Abstract: An impact wrench for tightening threaded joints by imparting a number of rotary blows to the threaded joint. The impact wrench comprises a housing which accommodates an impact clutch comprising an anvil and a hammer which consists of a driving member and a drive member, and a rotary drive of the hammer comprising an electric motor and a reduction gearing which has its output shaft mounted coaxially with the driving member of the hammer and is connected thereto for combined rotation only. The output shaft is connected to the driving member of the hammer by means of a spring-loaded pressure member accommodated in an axial bore of the output shaft and bodies of revolution contained in radial bores of the output shaft and engaging the spring-loaded pressure member. An annular groove is formed in the inner surface of the driving member of the hammer eccentrically relative thereto, and the bodies of revolution are received in the annular groove under the action of the spring-loaded pressure member.