You can freely build on How the Rogallo Flexible Wing Kite Works

What this patent covers

The patent describes a kite wing made of flexible material that lacks a rigid frame. Instead of using wooden struts to hold its shape, the wing relies on the pressure of the wind to inflate and maintain an airfoil shape while tethered. This design allows the kite to be lightweight, foldable, and capable of stable flight without heavy structural supports.

What is now free to use

All 0 claims of US 2546078 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 rigid-frame kites like traditional box or diamond designs.

• Does not cover motorized aircraft or powered flight vehicles.

• Does not cover wings made of rigid materials like metal or wood panels.

Who is building on this today

The design was extensively researched by NASA in the 1960s for spacecraft recovery systems. Today, recreational aviation companies continue to refine the Rogallo wing geometry for hang gliding and paragliding equipment.

Products built on expired version of this technology

How to cite this patent in your documentation

Individual. US Patent 2546078. Flexible kite. Granted 1951, expired 1968. 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.