Patent ID: 8573450

Claim:
An electrical caulking gun comprising: a gun body; a pushing rod movably mounted on the gun body; a motor connected to and driving the pushing rod to move relative to the gun body with a transmission device; a circuit board mounted in the gun body and electrically connected to the motor; a speed changing device electrically connected to the circuit board to control rotating speed of the motor via the circuit board; a trigger pivotally mounted on the gun body; a trigger switch mounted in the gun body and pressed by the trigger; and a clutching device mounted on the gun body at a position near the trigger and comprising a clutching switch mounted on the gun body and comprising a pressed segment exposed from the gun body; and a pushing segment integrally connected with the pressed segment, extending in the gun body and having an inclined pushing surface; a linking lever pivotally mounted in the gun body and having an abutting end abutting with the pushing surface on the pushing segment of the clutching switch; and a pushing end opposite to the abutting end and extending into the gun body; a clutching block movably mounted in the gun body and having an inclined pushed surface formed on one side of the clutching block; and an engaging rod formed on and protruding from the clutching block and detachably engaging the transmission device; at least one switch spring mounted between the clutching switch and the gun body to provide a force to push the clutching switch to extend out of the gun body; and a block spring mounted between the clutching block and the gun body to provide a force to push the engaging rod on the clutching block to engage the transmission device, wherein the linking lever further has a pushing pin mounted on the pushing end of the linking lever and abutting with the pushed surface of the clutching block; and the caulking gun assembly further comprising a speed-changing switch mounted on the gun body and comprising a pushbutton mounted on and exposed from the gun body; a pressed switch abutting with the pushbutton and electrically connected to the circuit board; and a button spring mounted between the pushbutton and the gun body to provide a force to push the pushbutton to extend out of the gun body.