{
  "patent_number": "US 387571",
  "country": "US",
  "title": "How the Revolving Door Was Invented",
  "original_title": "Storm-door structure",
  "summary": "The 1888 patent for the revolving door, designed to keep buildings warm while allowing people to enter and exit easily.",
  "what_it_does": "The patent describes a central vertical shaft with radiating wings that rotate within a circular enclosure. This mechanism creates a continuous seal between the outside and inside of a building. By maintaining this seal, the door prevents cold drafts from entering and warm air from escaping, which was a significant improvement over traditional swinging doors that let in large gusts of wind every time they opened.",
  "what_it_does_not_cover": [
    "Does not cover automatic or motorized revolving doors",
    "Does not cover sliding or traditional hinged door mechanisms",
    "Does not cover security-focused revolving doors with anti-tailgating sensors"
  ],
  "filed": null,
  "granted": "1888-08-07",
  "expires": null,
  "status": "active",
  "holder": "Theophilus Van Kannel",
  "holder_url": "https://patentbrief.org/company/theophilus-van-kannel",
  "inventors": [],
  "times_cited": 3,
  "tags": [
    "mechanical",
    "automotive"
  ],
  "abstract": null,
  "url": "https://patentbrief.org/patent/us/387571/revolving-door-van-kannel",
  "markdown_url": "https://patentbrief.org/patent/us/387571/revolving-door-van-kannel/md",
  "google_patents_url": "https://patents.google.com/patent/US387571",
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}