You can freely build on How a Simple Felt-Tip Marker Works

What this patent covers

The device functions as a primitive felt-tip marker. It consists of a hollow body that acts as an ink reservoir, containing a fibrous material saturated with marking fluid. A porous tip is held in contact with this reservoir, allowing ink to flow through the fibers via capillary action onto a surface. The design ensures a steady, controlled release of ink for writing or drawing.

What is now free to use

All 0 claims of US 2713176 are in the public domain. Specifically:

The 0 dependent claims add narrowing limitations and are also free.

What is NOT covered

Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

• Does not cover markers using pressurized ink delivery systems.

• Does not cover pens that use ball-point rolling mechanisms.

• Does not cover electronic or digital marking devices.

Who is building on this today

Major stationery manufacturers like Newell Brands (Sharpie) and Pilot Corporation continue to refine the material science of the porous tips and ink formulations based on these fundamental principles.

Products built on expired version of this technology

How to cite this patent in your documentation

Individual. US Patent 2713176. Marking device. Granted 1955, expired 1973. Now in the public domain.

Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.