Abstract: A compression-vacuum action percussive machine is proposed, which has a casing (1) accommodating a tool (7) and a cylinder (2) with a drive piston (3) and a striker (4) having a chamfer (10) on the end face engageable with the tool (7), and also a means for trapping the striker (4), which means is made in the form of a sleeve (11) with an annular groove (13), wherein a resilient ring (14) is mounted. The sleeve (11) has an inner annular rib (15), the diameter of which is smaller than the diameter of the inner wall (12) of the sleeve (11), the annular rib (15) being positioned at the end face of the sleeve (11) facing the striker (4). The inner diameter (d) of the resilient ring (14) is smaller than the diameter (D) of the extension (9) of the striker (4), which extension is situated after the striker chamfer (10).

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: A hand-held fastening element driving tool comprising a body accommodating a reciprocating actuator. The body carries a barrel wherein a striker is movable. The barrel holds a fastening element magazine. The striker consists of two parts closely fitted to each other. One part is a rectangular member whose cross-section follows the contour of a staple-shaped fastening element. The other member, together with the rectangular member, forms a figure circumscribing the head of a stem-shaped fastening element. The barrel cross-section is made as to suit the shape of the striker.

Abstract: A hand-held fastening element driving tool comprising a housing with a handle. A barrel holder with a barrel is free to move axially in the housing. The barrel holder has a extension enclosed in the housing and is provided with a cylindrical shoulder. This shoulder acts, through the agency of an elastic element, upon a corresponding shoulder of the housing. Another elastic element is fitted between the outer side surface of the barrel holder shoulder and the housing. A fastening element magazine has one end thereof connected to the barrel holder, and its other end is loosely articulated to the handle.

Abstract: A pneumatic impact tool comprising a casing having an interior space in which is mounted a piston for reciprocations under the action of compressed air for delivering useful blows, and ports of at least two exhaust passages opening into the interior space, one of the exhaust passages permanently communicating with atmosphere and the other with a chamber for preliminarily reducing the exhaust pressure. The chamber for preliminarily reducing the exhaust pressure is permanently connected through at least one passage to the exhaust passage communicating with atmosphere.

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: A percussive tool has a working tool mounted for reciprocations in a barrel. A collar is arranged between a shank and a working portion of the working tool. The shank of the working tool reciprocates in a guide bushing secured in the barrel to ensure reciprocations of the working tool. There is provide4d a member for determining the angular position of the working tool during the reciprications, the member comprising either the barrel proper in case of concrete breakers, or a hood, e.g. in chipping hammers. For positively controlling the angular position of the working tool, there is provided a spring having two portions of different cross-sectional configuration, a first portion being coupled for a combined rotation to the member determining the angular position of trhe working tool, and a second portion being of a cross-sectional configuration corresponding to the cross-sectional configuration of the working portion of the working tool.

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.