Abstract: A collapsible pen including a telescopically extensible barrel and a ballpoint refill cartridge having a ballpoint tip removably attached to the barrel. The pen further includes a ballpoint tip cap that releasably attaches to the refill cartridge. The extensible barrel includes an outer tubular member and at least two and most preferably three inner tubular members concentrically and coaxially mounted with respect to both the outer tubular member and to one another. Each inner tubular member has a smaller outer diameter than the overlying tubular members. The ballpoint tip cap, adapted for attachment to a key chain, is releasably attached to either the outer tubular member of the barrel or to the refill cartridge to cover the ballpoint tip. The pen has a fully extended length and a collapsed (retracted) length. With a barrel consisting of three inner tubular members, and the cap removed, the fully extended length of the pen is greater than twice the collapsed length of the pen.

Abstract: A collapsible pen including a telescopically extensible barrel and a ballpoint refill cartridge having a ballpoint tip removably attached to the barrel. The pen further includes a ballpoint tip cap that releasably attaches to the refill cartridge. The extensible barrel includes an outer tubular member and at least two and most preferably three inner tubular members concentrically and coaxially mounted with respect to both the outer tubular member and to one another. Each inner tubular member has a smaller outer diameter than the overlying tubular members. The ballpoint tip cap, adapted for attachment to a key chain, is releasably attached to either the outer tubular member of the barrel or to the refill cartridge to cover the ballpoint tip. The pen has a fully extended length and a collapsed (retracted) length. With a barrel consisting of three inner tubular members, and the cap removed, the fully extended length of the pen is greater than twice the collapsed length of the pen.

Abstract: A collapsible pen including a telescopically extensible barrel and a ballpoint refill cartridge having a ballpoint tip removably attached to the barrel. The pen further includes a ballpoint tip cap that releasably attaches to the refill cartridge. The extensible barrel includes an outer tubular member and at least two and most preferably three inner tubular members concentrically and coaxially mounted with respect to both the outer tubular member and to one another. Each inner tubular member has a smaller outer diameter than the overlying tubular members. The ballpoint tip cap, adapted for attachment to a key chain, is releasably attached to either the outer tubular member of the barrel or to the refill cartridge to cover the ballpoint tip. The pen has a fully extended length and a collapsed (retracted) length. With a barrel consisting of three inner tubular members, and the cap removed, the fully extended length of the pen is greater than twice the collapsed length of the pen.