Patent attributes
A ballpoint pen system has a pen housing, a top cap, and a ballpoint ink cartridge located in the pen housing. The top cap is located on a pen housing anterior end. In a first closed position a top cap anterior internal annular ridge and a top cap posterior internal annular ridge engage an anterior annular groove and a median annular groove of the pen housing, respectively. In a second, open position, the top cap anterior internal annular ridge and the top cap posterior internal annular ridge engage the median annular groove and a posterior annular groove of the pen housing, respectively. In a first position, the ballpoint tip is located below a top cap anterior end aperture. In a second position, the ballpoint tip is located above and through the top cap anterior end aperture.
