Impact mechanism for a repeatedly striking hand-held machine tool

A percussion mechanism for a repetitively hammering hand power tool in the form of a rotary hammer, the percussion mechanism having a striker (2), movable axially forward and backward in a guide barrel (1) and imparting impacts directly to an end section of a tool bit (4) that is insertable into the hand power tool, having a device (5) that exerts pressure on the striker (2), by which the striker (2) is capable of being set into a forward motion in the direction of the tool bit (4), wherein a blocking element (10) is provided, with which the striker (2) is blockable in its forward motion;

• and wherein the striking frequency of the striker (2) is adjustable by controlling the blocking time of the blocking element (10), so that the striking frequency of the striker (2) depends on how long the blocking element (10) blocks the forward motion of the striker (2), wherein the device exerting pressure on the striker (2) comprises a pressure reservoir (5) that is fillable with a gas and that is located on the side of the striker (2) diametrically opposite the tool bit (4), and wherein the blocking time of the blocking element (10) is controllable as a function of a pressure level in the pressure reservoir (5).