Reciprocal vibration type electric engraving pen

A reciprocal vibration type electric engraving pen, being driven by a main transmission shaft, comprising

• a rear shell, which is assembled with a front shell and is a hollow cylinder, with a rear end of the rear shell providing for the main transmission shaft to be positioned quickly, and an interior of the rear shell being assembled with a driving shaft, a first bearing, a second bearing, a collar, a small bearing and a C-shaped snap ring;
• with the driving shaft being transfixed respectively into the first bearing, the second bearing, the collar, the small bearing and the C-shaped snap ring;
• with a rear end of the driving shaft being a connection barrel to connect the main transmission shaft, a top front of the driving shaft being assembled with a driving bead, and the driving bead being off-centered on the top front of the driving shaft;
• and
• a front shell, which is a hollow cylinder and an interior of which is assembled with a buffer seat, a driven shaft, a spring, and a top assembly liner respectively, with the top assembly liner being assembled at a front end in the front shell to position the driven shaft in the front shell, a position of the driven shaft providing for abutting the spring, and a front end of the driven shaft being a chuck;
• wherein a rear end of the driven shaft is assembled with a driven pillar, the driven pillar is radially arranged on the rear end of the driven shaft, the driven shaft provides for touching the driving bead at front of the driving shaft, the driving shaft and the connection barrel are integrally formed, and the driving shaft is driven directly by the main transmission shaft to rotate;
• when the main transmission shaft drives the driving shaft to rotate, the driving bead revolves on a circular track simultaneously;
• whereas when the driven shaft is at a withdraw position, the driving bead hits the driven pillar twice while revolving by one turn, thereby achieving the object of double vibration for the driven shaft.