Patent ID: 9132541
Filing Date: 2015-09-15
Classification: B25D

Abstract:
1. A pneumatic hammer mechanism, comprising: a flying mass which is movable along an impact axis; an impact surface which limits a movement of the flying mass along the impact axis in an impact direction; an exciting piston which limits the movement of the flying mass along the impact axis opposite from the impact direction; a pneumatic chamber disposed between the flying mass and the exciting piston; and a drive for periodically moving the exciting piston with a stroke along the impact axis, wherein the flying mass is excited to a periodic movement between the impact surface and a minimum approach of the exciting piston in a cycle with a first phase and a second phase, wherein the first phase is a movement from the minimum approach of the exciting piston to the impact surface and the second phase is a movement from the impact surface to the minimum approach of the exciting piston, and wherein a graph of the movement of the first phase differs from a graph of the movement of the second phase; wherein the stroke is a function of a maximum length of the pneumatic chamber such that the flying mass decelerates, accelerates, and then decelerates again during the second phase, wherein due to the deceleration, acceleration, and then deceleration again of the flying mass a duration of a period of time for the second phase is greater than a duration of a period of time for the first phase and the flying mass has a greater velocity during the first phase than during the second phase.