Patent ID: 6668971
Filing Date: 2003-12-30
Classification: B23B,B25F

Abstract:
In a pneumatic hand tool having a handle with an exhaust passage including a main section having wall surfaces, a muffler improvement comprising:(a) an inner tube having an open proximal end and a distal end, the inner tube including at least one opening in addition to its open proximal end; (b) an outer tube positioned about the inner tube and including at least one airflow opening; the combination of inner tube and outer tube being located within the exhaust passage main section; the outer tube being sized to provide a passageway between itself and the wall surfaces of the main section; (c) an upper plate located near the inner tube proximal end; the upper plate closing off the exhaust passage main section such that a majority of the exhaust air is directed into the inner tube proximal end during use; and (d) an end cap attachable to the handle for closing off the exhaust passage, the end cap having an exit opening; wherein during use, exhaust air enters the inner tube proximal end, flows out the inner tube at least one opening, flows out the outer tube at least one airflow opening, passes through the passageway between the outer tube and the wall surfaces of the main section, and flows out the exit opening in the end cap; whereby the tortuous path slows the exhaust air and assists in dampening exhaust noise.