You can freely build on How George Nissen Invented the Modern Trampoline

What this patent covers

The patent describes a frame-supported apparatus designed for acrobatic tumbling. It utilizes a resilient, flexible canvas sheet stretched tightly across a rectangular frame by a series of tensioning springs. This configuration allows a user to jump onto the surface, which deforms to store kinetic energy and then releases it to launch the user upward, facilitating repetitive bouncing maneuvers.

What is now free to use

All 0 claims of US 2370990 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 non-spring-based jumping surfaces like simple foam pits.

• Does not cover inflatable bouncers or air-filled structures.

• Does not cover specialized training equipment that lacks the specific frame-and-spring tensioning system described.

Who is building on this today

Companies like Eurotramp and various fitness equipment manufacturers continue to refine the design for competitive and recreational use. The core mechanical principles established by Nissen remain the foundation for all modern spring-based trampolines.

Products built on expired version of this technology

How to cite this patent in your documentation

Individual. US Patent 2370990. Tumbling device. Granted 1945, expired 1962. 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.