| 摘要 |
A multiple writing element ball point pen includes relatively rotatable top and bottom barrel sections, a cylindrical cam being rotatable with the top section and a guide member carrying a pair of vertically movable cam followers being rotatable with the bottom section. A flexible band passing around a spindle located above the followers has an end connected to each follower so rotation of the cam to advance one follower causes the retraction of the other follower by the pull of the band. Each follower is connected to a chuck which engages a ball point cartridge to alternatively extend and retract the cartridges. |
