Architecture & Infrastructure
Automatic elevator door mechanism
The problem
Shaft doors were opened and closed by hand; an open shaft on an occupied floor was a fatal hazard.
The innovation
A mechanism that opened and closed the shaft door automatically in step with the cage's position.
How it worked
A flexible belt on the cage engages drums at each floor, working levers that operate the doors as the cage arrives and departs.
Why it mattered
Removed one of the most common causes of death in early elevator buildings.
The legacy
Door interlocks are now mandatory in elevator safety codes internationally.
You use this today
Every elevator you step into closes its own doors.
Sources
US Patent 371,207
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