{
  "patent_number": "US 31128",
  "country": "US",
  "title": "How Elisha Otis Invented the Modern Safety Elevator",
  "original_title": "Improvement in hoisting apparatus",
  "summary": "An 1861 patent by Elisha Otis describing a mechanism to prevent elevators from falling if their support cables snap.",
  "what_it_does": "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.",
  "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."
  ],
  "filed": null,
  "granted": "1861-01-15",
  "expires": null,
  "status": "active",
  "holder": "Elisha G. Otis",
  "holder_url": "https://patentbrief.org/company/elisha-g-otis",
  "inventors": [],
  "times_cited": 6,
  "tags": [
    "mechanical",
    "automotive"
  ],
  "abstract": null,
  "url": "https://patentbrief.org/patent/us/31128/otis-elevator-safety-brake",
  "markdown_url": "https://patentbrief.org/patent/us/31128/otis-elevator-safety-brake/md",
  "google_patents_url": "https://patents.google.com/patent/US31128",
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}