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).
The invention is based on a hand power tool, in particular a drilling- and/or chipping hammer, having a machine housing (12), a tool guiding element (16; 54), a hammer tube (14; 52), and a safety catch (32)--fixed in the housing in stationary fashion in the axial direction--for a striker (24) that can be driven by means of a drive piston (22) and that is actively joined with a tool (20) situated in a tool guiding element (16; 54). It is proposed that the tool guiding element (16; 54) is designed to be axially displaceable in relation to the machine housing (12).
The striking mechanism has a hammer barrel (3), which has at least one control opening (23) through which, in an idle position, the air can escape from the hammer barrel (3), and which in a striking position is closed by a covering (25) that prevents the escape of air. To achieve the greatest possible sealing off of the at least one control opening (23) and thus high efficiency of the striking mechanism, the covering (25) is molded from an elastomer.
In a fastener driving tool, a retention system for a piston comprises a buffer and a set of bearings in a cage, the bearings being abutted against the buffer. The buffer provides a force urging the bearing radially inwardly toward the piston so that the bearings retain the piston in a predetermined position when the piston is not being actuated.
A percussion tool, such as a drill or a chisel tool, including a percussion mechanism (7), a tool chuck (1), and a damping member (8) arranged between the tool chuck (1) and the percussion mechanism (7) for damping rebounds of a header (9) axially displaceable in the tool chuck (1), with the damping member (8) having, arranged one after another in the operational direction, a stop disc (86), an elastic ring (83), and a transmission element (81) having a cavity for receiving both the stop disc (86) an the elastic ring (86).
A percussion power tool includes a motor (6) located in the tool-housing (4) for driving the output member (12) and the percussion mechanism (10), a chuck (20) for receiving a working tool (22), a locking mechanism (24) for securing the chuck (20) on the output member (12) and including at least one locking member (26) which provides in a locking position thereof, for a formlocking connection between a connection member (30) of the chuck (20) and the output member (12), an adjusting sleeve (34) that prevents, in its blocking position, a radial displacement of the at least one locking member (26) from the locking position and a damping member (56) provided between the output member (12) and the connection member (30) and acting in the axial direction.
