You can freely build on How Jacob Schick Invented the Modern Magazine-Loading Safety Razor

What this patent covers

This patent describes a shaving implement designed to hold a stack of blades in a magazine. The mechanism allows a user to feed a new blade into the shaving head while simultaneously ejecting the old, dull blade. By using a mechanical slide or plunger, the device ensures the blade is properly seated and aligned without the user ever needing to handle the dangerous metal edges directly.

What is now free to use

All 0 claims of US 1721530 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 standard double-edge safety razors that require manual blade assembly.

• Does not cover electric shaving motors or oscillating blade mechanisms.

• Does not cover disposable plastic razors where the entire head is discarded.

Who is building on this today

The Schick brand, now owned by Edgewell Personal Care, continues to evolve the legacy of cartridge-based shaving systems. Modern razor manufacturers build upon the safety principles established here by refining how blades are housed and discarded.

Products built on expired version of this technology

How to cite this patent in your documentation

Individual. US Patent 1721530. Shaving implement. Granted 1929, expired 1948. 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.