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US 5,670,840 AGranted
Tungsten-halogen incandescent lamp with reduced risk of containment failure
OwnerGustino J. Lanese, Frank E. Zalar +1inventors
InventorsGustino J. Lanese, Frank E. Zalar, Ronald J. Olwert
Life of this patent
Estimating the term…
Abstract
A tungsten-halogen lamp has a light transmissive, IR coated, filament chamber enclosing a filament, the filament chamber being enclosed within an outer envelope. Fuses are connected to opposite ends of the filament to limit the magnitude and duration of an electrical arc across a break in the filament which, in combination with a fill gas pressure of no greater than 2500 Torr reduces the likelihood of containment failure.
Claims17
A lamp comprising:
- an outer envelope formed from light-transmissive material, the outer envelope having a wall thickness, x;
- a tungsten-halogen light source comprising a light transmissive filament chamber enclosing a filament, the filament chamber being coated with an infrared reflecting and visible light transmitting coating, the filament chamber having a wall thickness, y;
- an inert fill gas within the filament chamber having a room temperature pressure of no greater than 2500 Torr;
- an assembly that mounts the light source within the outer envelope;
- and
- a wall thickness ratio, x/y, of less than 0.65 whereby the likelihood of the outer envelope fracturing is substantially reduced.
3 more elements
A lamp comprising:
- an outer envelope formed from light-transmissive material, the outer envelope having a wall thickness, x;
- a double ended, tungsten-halogen light source comprising a light transmissive filament chamber enclosing a filament, the filament chamber being coated with an infrared reflecting and visible light transmitting coating, the filament chamber having a wall thickness, y;
- an inert fill gas within the filament chamber having a room temperature pressure of no greater than 2500 Torr;
- a wall thickness ratio, x/y, of less than 0.65;
- and
- a fuse connected to at least one of first and second opposite ends of the filament for limiting the duration and magnitude of an electrical arc in the event of a filament fracture whereby the likelihood of the outer envelope rupturing is substantially reduced, the fuse beginning to act within 1 and 3 half cycles of electrical current directed into the lamp and melting within approximately 6 cycles.
3 more elements
Dependencies are inferred from the claim text.