How Elisha Otis Invented the Modern Safety Elevator
An 1861 patent by Elisha Otis describing a mechanism to prevent elevators from falling if their support cables snap.
Original patent title: “Improvement in hoisting apparatus”
An 1861 patent by Elisha Otis describing a mechanism to prevent elevators from falling if their support cables snap. Granted to Elisha G. Otis in 1861 with 6 forward citations.
Key facts
Coverage
What does this patent actually cover?
This patent details a safety brake system for hoisting apparatuses, specifically elevators. It uses a spring-loaded mechanism that monitors the tension of the lifting cable. If the cable breaks or loses tension, the spring forces a set of ratchets or gripping teeth into the vertical guide rails of the elevator shaft, instantly locking the car in place and preventing a free fall.
The gap
What does this patent NOT cover?
- Does not cover electric motor control systems for elevator speed.
- Does not cover the modern electronic sensors used in today's elevators.
- Does not cover cable-less elevator systems using magnetic levitation.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The genius lies in the 'fail-safe' design: the safety mechanism is constantly held in an 'off' position by the tension of the cable, meaning it requires no human intervention to engage if the cable snaps.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Standard safety brakes in commercial building elevators
Otis Elevator Company legacy systems
Why it matters
The bigger picture
This invention transformed the elevator from a dangerous industrial tool into a safe passenger vehicle. By enabling people to trust vertical travel, it directly facilitated the birth of the skyscraper and changed the way cities grow.
Granted
January 15, 1861
Market context
Who's building on this
Companies in this space
The Otis Elevator Company remains a global leader in vertical transportation, continuing to refine these fundamental safety principles. Modern firms like Kone and Schindler also build upon these core mechanical safety concepts in their current designs.
Market impact
This patent effectively created the modern elevator industry by providing the necessary safety assurance for public adoption. It allowed buildings to expand vertically, fundamentally altering urban planning and real estate development globally.
Claim 1 — Plain English
What this patent covers
This patent details a safety brake system for hoisting apparatuses, specifically elevators. It uses a spring-loaded mechanism that monitors the tension of the lifting cable. If the cable breaks or loses tension, the spring forces a set of ratchets or gripping teeth into the vertical guide rails of the elevator shaft, instantly locking the car in place and preventing a free fall.
The clever bit
The genius lies in the 'fail-safe' design: the safety mechanism is constantly held in an 'off' position by the tension of the cable, meaning it requires no human intervention to engage if the cable snaps.
What it does not cover
- Does not cover electric motor control systems for elevator speed.
- Does not cover the modern electronic sensors used in today's elevators.
- Does not cover cable-less elevator systems using magnetic levitation.
PatentBrief Score
Impact Score
Limited data
Citation count
17/40
Early citations
Claim breadth
0/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$4K – $14K
Midpoint $9K · expired or expiring · industry ×0.9
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Concepts involved
Citations
Patent lineage
Cite this patent
(1861). How Elisha Otis Invented the Modern Safety Elevator (U.S. Patent No. 31,128). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/31128/otis-elevator-safety-brake
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How Elisha Otis Invented the Modern Safety Elevator cover?
An 1861 patent by Elisha Otis describing a mechanism to prevent elevators from falling if their support cables snap.
Who owns patent US 31128?
Elisha G. Otis owns this patent, granted in 1861.
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 31128 cited by?
This patent has been cited by 6 later patents that build on its ideas.
What problem does this patent solve?
This invention transformed the elevator from a dangerous industrial tool into a safe passenger vehicle. By enabling people to trust vertical travel, it directly facilitated the birth of the skyscraper and changed the way cities grow.
What does this patent NOT cover?
Does not cover electric motor control systems for elevator speed.
Patent monitoring