ASME-Landmark:Corning Ribbon Machine

While Thomas Edison perfected the first practical and durable filament in 1879, it was not until much later that electricity left the laboratory to become the universal source of light. This required a tremendous number of glass envelopes for light bulbs.

At the time, while filaments and bases could be manufactured, glass bulb envelopes could be made only by hand, or by mouth as it were, by glassblowers skilled in an ancient trade. These master craftsmen, called gaffers, learned their trade during a long apprenticeship and were few in number. Working at top speed in the red-orange radiance of a glass-melting tank, a team of two men, gaffer and assistant, could produce two bulbs per minute—and these hand-blown bulbs were expensive by the standards of the time, so that, even if large enough quantities could be produced, they would be beyond the means of most people.

Corning Glass Works and General Electric began developing rotary-style machines to produce light bulbs, but these still only produced 12, 24, or 48 bulbs during each revolution. In 1926, Corning Glass glassblower William J. Woods developed the ribbon machine, capable of producing up to two thousand light bulbs a minute.

In principle, molten glass sags through a hole in a horizontal plate into a mold below and is expanded by air pressure to form an electric light bulb envelope. Continuous motion is achieved by moving a preformed ribbon of glass with precisely matched chains of orifice plates, molds, and blowheads. See ASME website for more information