| 主权项 |
1. A writing instrument comprising:
an elongate body, a marking material actuator, marking material, and a marking material applicator; said elongate body comprising a first end and a second end, said first end configured for attaching to with said marking material applicator; said marking material applicator comprising a tip through which a ball extends, said ball having a diameter, said tip defining a socket into which said ball is received, said socket comprising a retainer portion having a rim with a smaller diameter than the diameter of said ball, thereby retaining said ball within the socket, said ball being rotatable within said socket; and said marking material actuator comprising an elongated protector, a constant force spring assembly for advancing said marking material against said ball, and an advancing mechanism for compressing said constant force spring; wherein said marking material is configured for extending from said marking material actuator and contacting the ball of the marking material applicator, wherein said marking material is applied to an outer surface of said ball. |
