Patent ID: 6923588

Claim:
A retractile mechanism for refills of writing instrument comprising an outer tube, a refill, an inner tube, and a compression spring, wherein the outer tube having a penholder, a pen nib, a tail and a pen clip; a button hole is disposed on the penholder of the outer tube while an elastic button is arranged on the pen clip so that the elastic button inserts through the button hole and leans against the inner tube; the refill is inserted into the inner tube and extends the pen nib; the inner tube is disposed inside the outer tube, sliding forward and backward freely and having a ring with load and a projecting edge for stopping on the front end thereof; the compression spring is arranged on the front end of the refill and installed inside the pen nib so as to make the refill being held elastically between the pen nib and the inner tube; when the pen nib is thrown forth, the inner tube with load pushes the refill moving forwards by inertia; while the projecting edge on the inner tube passes the button hole of the outer tube, the elastic button inserts through the button hole, presses and locks with the projecting edge; the inner tube and the extended nib point are ready for writing; when the elastic button is pulled out, both the inner tube and the refill retracts by the pushing of the compression spring, back to the storage status.