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Sealed beam headlamps have played a significant role in the history of the U.S. automotive industry. Once the standard for all vehicles sold in the country, these unique headlights influenced car design and provided several advantages to consumers. In this blog, we will walk through the timeline of sealed beam headlamps in the United States. We'll also explore how their development and eventual decline shaped the evolution of automotive lighting.
The Birth of Sealed Beam Headlamps (1940)
The first sealed beam headlamps were introduced in 1940 by the General Electric Company. This innovative design featured a single unit that was easy to install on any vehicle and not subject to the wear and tear of traditional bulbs. The sealed beam headlamp design was quickly adopted in the United States and soon became the industry standard.
The Golden Age of Sealed Beam Headlamps (1940-1975)
From 1940 to 1956, U.S. law required all cars to use two 7" round sealed beam headlamps, with one lamp on each side of the vehicle. Each lamp was dual filament, serving as both low and high beams. In 1957, the U.S. law changed, allowing the use of four sealed beam headlamps, each lamp measuring 5 3/4". Two served as low beams, and two as high beams.
Between 1958 and 1975, most American cars adopted four round lamps, which could be arranged horizontally, vertically, or diagonally. Some vehicles continued with two lamps. During this period, sealed beam headlamps dominated the automotive industry. They were the go-to choice for both manufacturers and consumers.
Transition to Rectangular Headlamps (1975-1984)
In 1975, U.S. law allowed the use of rectangular headlamps. Two-lamp systems used 200mm size lamps, while four-lamp systems used 165mm size lamps. Most American cars switched to rectangular lamps, but a few remained with round lamps. This period marked the beginning of the end of the dominance of sealed beam headlamps in the United States.
The Advent of Composite Headlamp Assemblies (1984-Present)
In 1984, U.S. law permitted the use of composite headlight assemblies with replaceable bulbs. However, some lower-priced vehicles and cars with hidden headlights continued with sealed beam headlamps. By the early 1990s, most cars had transitioned to composite headlight assemblies, signaling the automotive industry's decline in sealed beam headlamps.
Today, no new cars or light trucks are sold with sealed beam headlights in the United States. However, the impact of sealed beam headlamps on automotive history and design should not be underestimated. The evolution of headlamp design has led to more advanced, customizable, and versatile lighting systems that better cater to drivers' needs.
SEALED BEAM: HOLLEY RETROBRIGHT LED HEADLIGHTS (7" ROUND)
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