Patent ID: 8646657

Claim:
An electric caulking gun having: a body having a front end; a rear end; a side; a lower end; a pushing shaft movably connected to the rear end of the body to push a caulking tube; a motor mounted on the side of the body to provide a power to the pushing shaft to enable the pushing shaft to move relative to the body; a gearbox mounted in the body, connected to the pushing shaft and the motor to transmit the power of the motor to the pushing shaft and having a sun gear rotatably mounted in the body and having an external surface; an internal surface; multiple mounting slots formed in the external surface of the sun gear at intervals; and multiple engaging teeth formed around the internal surface of the sun gear to form the sun gear as an inner gear; a transmission device rotatably mounted in the body near the lower end of the body; a circuit board mounted in the body above the gearbox and electrically connected to the motor and the transmission device; and a switch pressably connected to the body below the gearbox and having a top; and an actuating assembly mounted in the body, connected to the switch and selectively engaging the sun gear of the gearbox and having a connecting arm mounted in the body, pivotally connected to the switch and having a lower end pivotally connected to the top of the switch; and an upper end extending upwardly to the sun gear of the gearbox; a linking arm being curved, pivotally connected to the body and connected to the connecting arm and having a straight end pivotally connected to the body above the connecting arm; a curved end; and a pushing rod connected to the curved end of the linking arm and the upper end of the connecting arm and having an abutting end transversally extending out of the curved end of the linking arm and extending toward the sun gear of the gearbox; an actuating element movably mounted in the body, selectively engaging one of the mounting slots of the sun gear and having a wedge mount movably mounted in the body and having an outer surface; an inner surface facing the external surface of the sun gear; a wedge face obliquely formed on the inner surface of the wedge mount and abutting against the abutting end of the pushing rod; and a spring mounted between the body and the outer surface of the wedge mount to push the wedge mount to move toward the sun gear; and an engaging block formed on and protruding from the outer surface of the wedge mount adjacent to the wedge face and selectively engaging one of the mounting slots of the sun gear; an oscillating arm pivotally connected to the body, connected to the connecting arm and having a middle pivotally connected to the body above the connecting arm; a bottom end extending downwardly adjacent to the lower end of the connecting arm; and a top end; and a pressing button movably and pressably mounted in the body, connected to the oscillating arm and having an inner end connected to the top end of the oscillating arm; and an outer end extending out of the body.