Patent ID: 7604528

Claim:
An electric grinding gun having a body having a casing being hollow; a rechargeable battery being mounted detachably in the casing; a protective circuit board being mounted in the casing and being electrically connected to the rechargeable battery; a switch being mounted in the casing and being electrically connected to the protective circuit board of the body; a motor being mounted in the casing and being electrically connected to the switch and having a front side; a rotating shaft being connected rotatably to the front side of the motor and having an external surface; and multiple engaging teeth being formed around the external surface of the rotating shaft; a cooling fin being mounted in the casing near the motor; and a mounting barrel being mounted on the casing; a gear reduction device being rotatably mounted in the mounting barrel of the body and having a seat being rotatably mounted in the mounting barrel of the body and having a rear end; a front end; an external surface; a shaft hole being formed in the rear end of the seat and being mounted around the rotating shaft of the motor; two gear recesses being formed in the external surface of the seat near the rear end and aligning with the engaging teeth of the motor; and a connecting axle being formed on and protruding from the front end of the seat and having a free end; two planet gears being rotatably mounted in the gear recesses of the seat and engaging the engaging teeth on the rotating shaft, and each planet gear having a mounting post connected to the seat to hold the planet gear in a corresponding gear recess of the seat; and a gear ring being securely mounted in the mounting barrel of the body, being mounted around the seat and having an internal surface; and multiple engaging teeth being formed around the internal surface of the gear ring and engaging the planet gears to make the seat rotating relative to the gear ring; a holding cap being securely mounted around the mounting barrel of the body to hold the gear reduction device in the mounting barrel and having a front side; and a through hole being formed through the front side of the holding cap, wherein the connecting axle of the seat extends out of the through hole of the holding cap; and an actuating device being connected detachably to the seat of the gear reduction device and having a panel being connected detachably to the connecting axle of the seat and having a front side; and an adhering layer being mounted on the front side of the panel.