# How Early Vehicle Airbag Safety Systems Work

> A 1968 patent describing an early vehicle safety system that uses a rapidly inflating confinement to protect passengers during a collision.

- **Patent:** US 3552770
- **Original title:** Safety device
- **Owner:** Eaton Yale and Towne Inc
- **Granted:** 1971
- **Status:** Public domain (expired)
- **Times cited:** 26
- **Field:** automotive, mechanical

## What it does

The device functions as an occupant restraint system that remains collapsed during normal operation. Upon detecting an accident, it triggers an expansion process to deploy a confinement, which acts as a cushion. The patent details two primary methods for inflation: using a fluid reservoir with a zero-reaction diffuser to direct gas flow, or utilizing gas-generating chemical materials that ignite to fill the confinement instantly.

## What it does NOT cover

- Does not cover electronic crash sensors or modern accelerometer-based deployment logic
- Does not cover multi-stage inflation systems that adjust pressure based on occupant size
- Does not cover side-curtain or knee-based airbag configurations

## The clever bit

The use of a zero-reaction diffuser allowed for the rapid movement of high-pressure gas without creating a massive physical recoil force that could damage the vehicle's dashboard structure during deployment.

## Real-world examples

1. Early automotive supplemental restraint systems (SRS)
2. Experimental 1970s vehicle safety prototypes

## Why it matters

This patent represents a foundational step in automotive safety technology. It helped transition the industry from reliance on basic seatbelts toward the active, automated restraint systems that are now standard in every passenger vehicle worldwide.

## Frequently asked questions

### What does How Early Vehicle Airbag Safety Systems Work cover?

A 1968 patent describing an early vehicle safety system that uses a rapidly inflating confinement to protect passengers during a collision.

### Who owns patent US 3552770?

Eaton Yale and Towne Inc owns this patent, granted in 1971.

### 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 3552770 cited by?

This patent has been cited by 26 later patents that build on its ideas.

### What problem does this patent solve?

This patent represents a foundational step in automotive safety technology. It helped transition the industry from reliance on basic seatbelts toward the active, automated restraint systems that are now standard in every passenger vehicle worldwide.

### What does this patent NOT cover?

Does not cover electronic crash sensors or modern accelerometer-based deployment logic

**Full plain-English explainer:** https://patentbrief.org/patent/us/3552770/automotive-airbag-safety-device

**Original patent:** https://patents.google.com/patent/US3552770

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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 the Modern Three-Point Car Seatbelt Works](https://patentbrief.org/patent/us/3043625/three-point-seatbelt) — The foundational 1959 patent for the three-point seatbelt, which secures both the torso and lap to prevent injury during vehicle collisions.
- [How Self-Balancing Vehicles Warn Users Before They Tip Over](https://patentbrief.org/patent/us/6302230/segway-personal-transporter) — A safety system for self-balancing vehicles that monitors how much 'room' the machine has left to accelerate before it loses its ability to stay upright.
- [Ralph Teetor's Speed Control Device for Automobiles](https://patentbrief.org/patent/us/2519859/cruise-control-teetor) — A 1948 invention by Ralph Teetor that introduced the mechanical foundation for modern cruise control by creating a system to resist accelerator pedal movement at a set speed.
- [How the Modern Waterbed Works](https://patentbrief.org/patent/us/3585356/waterbed-liquid-support) — A 1971 patent describing a liquid-filled, heated furniture support designed to cradle human bodies without letting them touch the bottom of the container.
- [How Elisha Otis Invented the Modern Safety Elevator](https://patentbrief.org/patent/us/31128/otis-elevator-safety-brake) — An 1861 patent by Elisha Otis describing a mechanism to prevent elevators from falling if their support cables snap.