| 摘要 |
A telescopic ball-point pen includes a tubular body, including a sliding axial tube, which in turn includes a refill tank. An interior surface of the body and an exterior surface of the sliding axial tube are threaded to form a driver screw portion, and an interior surface of the sliding axial tube and an exterior surface of the refill tank are threaded to form a follower screw portion. A pitch of the follower screw portion is greater than that of the driver screw portion so that the amount of front-and-back movement of the refill tank is greater than that of the sliding axial tube per rotation. A rear end of the sliding axial tube is fixed to a sheath. When the sheath and the body are rotated, the tip of a ball-point pen refill removably received within the refill tank is projected beyond, or received within, the pen. |
