# How Early Hard Disk Drives Accessed Data Quickly

> A 1970 patent detailing a mechanical system for moving read-write heads across magnetic disks to retrieve stored information rapidly.

- **Patent:** US 3503060
- **Original title:** Direct access magnetic disc storage device
- **Owner:** JOHN J LYNOTT
- **Granted:** 1970
- **Status:** Public domain (expired)
- **Times cited:** 9
- **Field:** semiconductors, mechanical

## What it does

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 it does NOT cover

- 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.

## The clever bit

The invention refined the mechanical linkage and control systems required to move a physical head to a specific track with high precision and speed, minimizing the time spent waiting for the disk to rotate.

## Real-world examples

1. Early IBM mainframe disk storage units
2. Hard disk drive mechanical head actuators

## Why it matters

This technology was foundational for the transition from slow, sequential tape storage to the high-speed random access storage that defines modern computing. It enabled the development of early mainframe disk drives, which allowed computers to retrieve files and execute programs much faster than previously possible.

## Frequently asked questions

### What does How Early Hard Disk Drives Accessed Data Quickly cover?

A 1970 patent detailing a mechanical system for moving read-write heads across magnetic disks to retrieve stored information rapidly.

### Who owns patent US 3503060?

JOHN J LYNOTT owns this patent, granted in 1970.

### When does this patent expire?

This patent has expired and is now in the public domain — anyone can use the invention freely.

### What is patent US 3503060 cited by?

This patent has been cited by 9 later patents that build on its ideas.

### What problem does this patent solve?

This technology was foundational for the transition from slow, sequential tape storage to the high-speed random access storage that defines modern computing. It enabled the development of early mainframe disk drives, which allowed computers to retrieve files and execute programs much faster than previously possible.

### What does this patent NOT cover?

Does not cover solid-state storage or flash memory technologies.

**Full plain-English explainer:** https://patentbrief.org/patent/us/3503060/hard-disk-drive

**Original patent:** https://patents.google.com/patent/US3503060

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._


## Related patents

Semantically similar inventions in the PatentBrief corpus:

- [How Alan Turing Designed Early Computer Memory Systems](https://patentbrief.org/patent/us/2799449/turing-computer-data-storage) — A 1951 patent by Alan Turing and colleagues describing methods for moving data between different storage types in early digital computers.
- [How the Floppy Disk's Protective Jacket Cleans the Disk](https://patentbrief.org/patent/us/3668658/floppy-disk-diskette) — An IBM patent from 1972 describing a protective, non-removable cover for a magnetic disk that uses a built-in cleaning material to wipe the disk surface while it spins.
- [How Wang An Invented the Magnetic Pulse Memory Core](https://patentbrief.org/patent/us/2708722/magnetic-core-memory-wang) — A 1949 invention by An Wang that used magnetic cores to store and transfer binary data, forming the backbone of early computer memory.
- [How Douglas Engelbart Invented the Computer Mouse](https://patentbrief.org/patent/us/3541541/computer-mouse-input-device) — The 1970 patent for the X-Y position indicator, better known as the computer mouse, which allowed users to move a cursor across a screen for the first time.
- [How Ampex Invented Modern Video Recording on Magnetic Tape](https://patentbrief.org/patent/us/2956114/videotape-recorder-ampex) — This 1955 invention enabled the recording of high-frequency television signals onto magnetic tape, replacing the expensive and low-quality film recording methods of the era.