Pen with pressurizing mechanism to pressurize ink refill

A pen comprising:

• barrel;
• an ink-containing refill disposed in the barrel to undergo movement in an axial direction between a writing position and a retracted position;
• and a pressurizing mechanism to pressurize a rear space of the refill when the refill is moved to the writing position, the pressurizing mechanism comprising a refill holder that holds a rear portion of the refill and that has an opening at its rear end, an elastic airtight member surrounding a periphery of the refill while providing a vent path between the airtight member and the refill, a return spring holder which holds the airtight member and which is connected to a front portion of the refill holder to undergo movement in the axial direction within a predetermined range, a return spring that urges the return spring holder axially backwardly to a position abutting on a stopper disposed in the barrel, a compression cylinder fitted to a rear portion of the refill holder and having a compression chamber at its inside, and a knocking-type feeding mechanism disposed in the barrel to move the compression cylinder back and forth in the axial direction;
• wherein an inner face of the refill holder faces the airtight member so that when the refill holder advances, the inner face of the refill holder presses and elastically deforms the airtight member to bring an inner face of the airtight member into close contact with an outer periphery face of the refill to close the vent path, the compression cylinder and the refill holder are connected by releasable connecting means for connecting the compression cylinder and the refill holder so that when the compression cylinder advances, the compression cylinder and the refill holder can advance together to a position where the refill holder presses and deforms the airtight member and then releasing the connection of the compression cylinder and the refill holder so that the compression cylinder can move closer to the refill holder, and the refill holder with the refill and the return spring holder with the airtight member are moved forward by the compression cylinder against the return spring.