Patent ID: 7654886

Claim:
A pneumatic grinder structure comprising: a housing having a rotor and a brake rod therein, said brake rod being mounted on an eccentric seat; an air chamber stand mounted in said housing and receiving said rotor and said brake rod therein, said air chamber stand having an air chamber therein, said air chamber stand comprising: a cylinder having an inlet hole and an exhaust hole formed thereon, said inlet hole and said exhaust hole being in fluid communication with said air chamber; an upper cover affixed to one side of said cylinder; and a lower cover affixed to an opposite side of said cylinder, at least one of said upper cover and said lower cover having a lateral exhaust hole, said lateral exhaust hole having a vertical internal borehole section in communication with said air chamber, said lateral exhaust hole having a transverse external borehole section protruding from an edge of the one of said upper cover and said lower cover.