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US 3503060Freedom to Build
Public domain since 1988

You can freely build on How Early Hard Disk Drives Accessed Data Quickly

This patent expired in 1988. Every claim — 0 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.

Original assignee

JOHN J LYNOTT

Patent granted

1970

Expired

1988

Forward citations

9

What this patent covers

This patent describes a mechanical assembly for a magnetic disk storage device. It focuses on the movement of a transducer, or read-write head, across the surface of a rotating magnetic disk. By using a specific actuator mechanism, the device positions the head over precise tracks on the disk to read or write data. This allowed computers to access information stored at different locations on the disk without needing to read through all the data sequentially.

What is now free to use

All 0 claims of US 3503060 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 solid-state storage or flash memory technologies.

    • Does not cover software-based file systems or data organization methods.

    • Does not cover the magnetic recording medium itself, only the mechanical positioning hardware.

    Who is building on this today

    Companies like Western Digital, Seagate, and Toshiba continue to evolve the mechanical and magnetic principles of hard disk drives, though the industry has shifted significantly toward solid-state storage.

    Products built on expired version of this technology

    Early IBM mainframe disk storage units

    Hard disk drive mechanical head actuators

    How to cite this patent in your documentation

    JOHN J LYNOTT. US Patent 3503060. Direct access magnetic disc storage device. Granted 1970, expired 1988. 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.

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