Two piece twist action retractable writing instrument

A retractable pen, comprising;

• an elongate cartridge including a first end and a second end;
• a cap having a recess with an inner surface with first threads thereon, the cartridge being partially received in the recess such that the first end of the cartridge is fixedly attached to the cap;
• and
• an elongate barrel including first and second open ends and a through channel fluidly interconnecting the first and second open ends, a portion of the barrel having an outer surface with second threads thereon, the portion of the barrel including the first open end being snugly received in the recess such that the first and second threads are in threaded engagement with each other, the cartridge is received in and extends through the through channel, and the barrel and the cap are rotatingly movable relative to each other via the threaded engagement between:
• an extended position in which the second end of the cartridge extends through and out of the second open end of the barrel;
• a retracted position in which the second end of the cartridge is disposed within the barrel;
• and
• a ring attached to the barrel adjacent to the first open end.

A retractable pen, comprising:

• an elongate cartridge including a first end and a second end;
• a cap having a recess with an inner surface with first threads thereon, the cartridge being partially received in the recess such that the first end of the cartridge is fixedly attached to the cap;
• and
• an elongate barrel including first and second open ends and a through channel fluidly interconnecting the first and second open ends, a portion of the barrel having an outer surface with second threads thereon, the portion of the barrel including the first open end being snugly received in the recess such that the first and second threads are in threaded engagement with each other, the cartridge is received in and extends through the through channel, and the barrel and the cap are rotatingly movable relative to each other via the threaded engagement between:
• an extended position in which the second end of the cartridge extends through and out of the second open end of the barrel;
• a retracted position in which the second end of the cartridge is disposed within the barrel, wherein each of the first and second threads are male.

A retractable pen, comprising:

• an elongate ink cartridge including a first end and a second end;
• a cap having a recess with an inner surface with first threads thereon, the cartridge being partially received in the recess such that the first end of the cartridge is fixedly attached to the cap;
• an elongate barrel including first and second open ends and a through channel fluidly interconnecting the first and second open ends, a portion of the barrel having an outer surface with second threads thereon, the portion of the barrel including the first open end being snugly received in the recess such that the first and second threads are in threaded engagement with each other, the cartridge is received in and extends through the through channel, and the barrel and the cap are rotatingly movable relative to each other via the threaded engagement between:
• an extended position in which the second end of the cartridge extends beyond the second open end of the barrel;
• and
• a retracted position in which the second end of the cartridge is disposed within the barrel;
• a first ring attached to the barrel and configured to engage the first threads on the cap in the retracted position;
• and
• a second ring attached to the barrel and configured to engage the first threads on the cap in the extended position.

A retractable pen, comprising:

• an elongate ink cartridge including a first end and a second end;
• a cap having a recess with an inner surface with first threads thereon, the cartridge being partially received in the recess such that the first end of the cartridge is fixedly attached to the cap;
• an elongate barrel including first and second open ends and a through channel fluidly interconnecting the first and second open ends, a portion of the barrel having an outer surface with second threads thereon, the portion of the barrel including the first open end being snugly received in the recess such that the first and second threads are in threaded engagement with each other, the cartridge is received in and extends through the through channel, and the barrel and the cap are rotatingly movable relative to each other via the threaded engagement between:
• an extended position in which the second end of the cartridge extends beyond the second open end of the barrel;
• and
• a retracted position in which the second end of the cartridge is disposed within the barrel;
• means for preventing the cap from being removed from the barrel;
• and
• means for preventing the cartridge from being extended more than a predetermined distance out of the second open end of the barrel, wherein the means for preventing the cartridge from being extended more than a predetermined distance out of the second open end of the barrel comprises a ring attached to the barrel and configured to engage the first threads on the cap.

A retractable pen, comprising:

• an elongate ink cartridge including a first end and a second end;
• a cap having a recess with an inner surface with first threads thereon, the cartridge being partially received in the recess such that the first end of the cartridge is fixedly attached to the cap;
• an elongate barrel including first and second open ends and a through channel fluidly interconnecting the first and second open ends, a portion of the barrel having an outer surface with second threads thereon, the portion of the barrel including the first open end being snugly received in the recess such that the first and second threads are in threaded engagement with each other, the cartridge is received in and extends through the through channel, and the barrel and the cap are rotatingly movable relative to each other via the threaded engagement between:
• an extended position in which the second end of the cartridge extends beyond the second open end of the barrel;
• and
• a retracted position in which the second end of the cartridge is disposed within the barrel;
• and
• means for preventing the cap from being removed from the barrel, wherein each of the first and second threads are male.

A retractable pen, comprising:

• an elongate ink cartridge including a first end and a second end;
• a cap having a recess with an inner surface with first threads thereon, the cartridge being partially received in the recess such that the first end of the cartridge is fixedly attached to the cap;
• an elongate barrel including first and second open ends and a through channel fluidly interconnecting the first and second open ends, a portion of the barrel having an outer surface with second threads thereon, the portion of the barrel including the first open end being snugly received in the recess such that the first and second threads are in threaded engagement with each other, the cartridge is received in and extends through the through channel, and the barrel and the cap are rotatingly movable relative to each other via the threaded engagement between:
• an extended position in which the second end of the cartridge extends beyond the second open end of the barrel;
• and
• a retracted position in which the second end of the cartridge is disposed within the barrel;
• and
• means for preventing the cap from being removed from the barrel, wherein the preventing means comprises a ring attached to the barrel and configured to engage the first threads.