Semi-adjustable articulator with mounted casts. An articulator is a mechanical device used in dentistry to which casts of the maxillary (upper) and mandibular (lower) teeth are fixed, reproducing recorded positions of the mandible in relation to the maxilla.
The Greek scholar Heron of Alexandria created the earliest known automatic door in the 1st century AD during the era of Roman Egypt. The first foot-sensor-activated automatic door was made in China during the reign of Emperor Yang of Sui (r. 604â618), who had one installed for his royal library.
Alexander Miles. Alexander Miles was an African-American inventor who was best known for being awarded a patent for an automatically opening and closing elevator door design in 1887. Contrary to many sources, Miles was not the original inventor of this device. In 1874, 13 years before Miles' patent was awarded, John W. Meaker was awarded U.S. Patent 147,853 for the invention of the first automatic elevator door system.