High pressure metal vapor discharge lamps of improved efficacy

Claim 2

A high pressure metal vapor arc discharge lamp for general illuminating purposes and rated for a power input of not more than 250 watts, said lamp comprising an arc chamber having a shape selected from the group of shapes consisting essentially of ellipsoids and spheroids and approximations thereof, said arc chamber being defined within an envelope made of light-transmitting material and having a wall thickness not exceeding 1.5 millimeters, a fill of mercury and metal halide contained within said chamber and adapted to be vaporized during operation of the lamp, said arc chamber having a wall area of such value as to effect a wall loading in the range of from about 10 to 35 watts/cm 2 when the lamp is operated at rated wattage, said arc chamber having a length-to-diameter ratio (X/D) in the range of from about 0.9 to 2.5, a pair of electrodes supported within said arc chamber on inleads extending through said envelope, said electrodes having opposing tips spaced from one another by a distance L of such value as to effect an arc loading in the range of from about 60 to 150 watts/cm when the lamp is operated at rated wattage, the insertion factor Y of said electrodes being in the range of from about 0.1 to 0.6, where Y is equal to the quantity (X-L)/X, and neck seals hermetically bonding said inleads to said envelope, said neck seals and any heat-conserving devices associated therewith collectively subtending less than 10 percent of the solid angle at the center of said arc chamber.

Claim 3

A lamp as defined in claim 1 and rated for a power input of about 250 watts, said arc chamber having a generally ellipsoidal shape, the wall loading being in the range of from about 10 to 25 watts/cm 2 , the (X/D) ratio being in the range of from about 1.5 to 2.5, the arc loading being in the range of from about 100 to 150 watts/cm, said neck seals and any heat-conserving devices associated therewith collectively subtending less than 1 percent of the solid angle at the center of the arc chamber.

Claim 4

A lamp as defined in claim 1 and rated for a power input of not more than 70 watts, said arc chamber having a volume of less than 1 cubic centimeter, the wall loading being in the range of from about 15 to 35 watts/cm 2 , the arc loading being in the range of from about 60 to 120 watts/cm, said neck seals and any heat-conserving devices associated therewith collectively subtending less than 7 percent of the solid angle at the center of the arc chamber.

Claim 5

A high pressure metal vapor arc discharge lamp for general illuminating purposes and rated for a power input of not more than 250 watts, said lamp comprising an arc chamber having a shape selected from the group of shapes consisting essentially of ellipsoids and spheroids and approximations thereof, said arc chamber being defined within an envelope made of light-transmitting material and having a wall thickness not exceeding 1.5 millimeters, a fill of mercury and metal halide contained within said chamber and adapted to be vaporized during operation of the lamp, said arc chamber having a wall area of such value as to effect a wall loading in the range of from about 10 to 35 watts/cm 2 when the lamp is operated at rated wattage, said arc chamber having a length-to-diameter ratio (X/D) in the range of from about 0.9 to 2.5, the entire internal and external surfaces of said envelope being free of heat-conserving coatings, a pair of electrodes supported within said arc chamber on inleads extending through said envelope, said electrodes having opposing tips spaced from one another by a distance L of such value as to effect an arc loading in the range of from about 60 to 150 watts/cm when the lamp is operated at rated wattage, the insertion factor Y of said electrodes being in the range of from about 0.1 to 0.6, where Y is equal to the quantity (X-L/X), and neck seals hermetically bonding said inleads to said envelope and subtending less than 10 percent of the solid angle at the center of said arc chamber.

Claim 6

A high pressure metal vapor arc discharge lamp for general illuminating purposes and rated for a power input of not more than 250 watts, said lamp comprising an arc chamber having a shape selected from the group of shapes consisting essentially of ellipsoids and spheroids and approximations thereof, said arc chamber being defined within an envelope made of light-transmitting material and having a wall thickness not exceeding 1.5 millimeters, a fill of mercury and metal halide contained within said chamber and adapted to be vaporized during operation of the lamp, said arc chamber having a wall area of such value as to effect a wall loading in the range of from about 10 to 35 watts/cm 2 when the lamp is operated at rated wattage, said arc chamber having a length-to-diameter ratio (X/D) in the range of from about 0.9 to 2.5, the entire internal and external surfaces of said envelope being free of heat-conserving coatings, a pair of electrodes supported within said arc chamber on inleads extending through said envelope, said electrodes having opposing tips spaced from one another by a distance L of such value as to effect an arc loading in the range of from about 60 to 150 watts/cm when the lamp is operated at rated wattage, the insertion factor Y of said electrodes being in the range of from about 0.1 to 0.6, where Y is equal to the quantity (X-L/X), and neck seals hermetically bonding said inleads to said envelope and subtending less than 10 percent of the solid angle at the center of said arc chamber.

Claim 7

A high pressure metal vapor arc discharge lamp for general illuminating purposes and rated for a power input of not more than 70 watts, said lamp comprising an arc chamber having a shape selected from the group of shapes consisting essentially of ellipsoids and spheroids and approximations thereof, said arc chamber having a volume of less than one cubic centimeter and being defined within an envelope made of light-transmitting material and having a wall thickness not exceeding 1.5 millimeters, a fill of mercury and metal halide contained within said chamber and adapted to be vaporized during operation of the lamp, said arc chamber having a wall area of such value as to effect a wall loading in the range of from about 15 to 35 watts/cm 2 when the lamp is operated at rated wattage, said arc chamber having a length-to-diameter ratio (X/D) in the range of from about 0.9 to 2.5, the entire internal and external surfaces of said envelope being free of heat-conserving coatings, a pair of electrodes supported within said arc chamber on inleads extending through said envelope, said electrodes having opposing tips spaced from one another by a distance L of such value as to effect an arc loading in the range of from about 60 to 120 watts/cm when the lamp is operated at rated wattage, the insertion factor Y of said electrodes being in the range of from about 0.1 to 0.6, where Y is equal to the quantity (X-L/X), and neck seals hermetically bonding said inleads to said envelope and subtending less than 7 percent of the total solid angle surrounding the center of said arc chamber.

Claim 8

A high pressure metal vapor arc discharge lamp for general illuminating purposes and rated for a power input of not more than 70 watts, said lamp comprising an arc chamber having a shape selected from the group of shapes consisting essentially of ellipsoids and spheroids and approximations thereof, said arc chamber having a volume of less than one cubic centimeter and being defined within an envelope made of light-transmitting material and having a wall thickness not exceeding 1.5 millimeters, a fill of mercury and metal halide contained within said chamber and adapted to be vaporized during operation of the lamp, said arc chamber having a wall area of such value as to effect a wall loading in the range of from about 15 to 35 watts/cm 2 when the lamp is operated at rated wattage, said arc chamber having a length-to-diameter ratio (X/D) in the range of from about 0.9 to 2.5, the entire internal and external surfaces of said envelope being free of heat-conserving coatings, a pair of electrodes supported within said arc chamber on inleads extending through said envelope, said electrodes having opposing tips spaced from one another by a distance L of such value as to effect an arc loading in the range of from about 60 to 120 watts/cm when the lamp is operated at rated wattage, the insertion factor Y of said electrodes being in the range of from about 0.1 to 0.6, where Y is equal to the quantity (X-L/X), and neck seals hermetically bonding said inleads to said envelope and subtending less than 7 percent of the total solid angle surrounding the center of said arc chamber.

Claim 9

A high pressure metal vapor arc discharge lamp for general illuminating purposes and rated for a power input of not more than 70 watts, said lamp comprising an arc chamber having a substantially ellipsoidal shape and having a volume of less than one cubic centimeter, said arc chamber being defined within an envelope made of fused silica and having a wall thickness not exceeding 1.5 millimeters, a fill of mercury and metal halide contained within said chamber and adapted to be vaporized during operation of the lamp, said arc chamber having a wall area of such value as to effect a wall loading in the range of from about 15 to 35 watts/cm 2 when the lamp is operated at rated wattage, said arc chamber having a length-to-diameter ratio (X/D) in the range of from about 1.5 to 2.5, the entire internal and external surfaces of said envelope being free of heat-conserving coatings, a pair of electrodes supported within said arc chamber on inleads extending through said envelope, said electrodes having opposing tips spaced from one another by a distance L of such value as to effect an arc loading in the range of from about 60 to 120 watts/cm when the lamp is operated at rated wattage, the insertion factor Y of said electrodes being in the range of from about 0.1 to 0.6, where Y is equal to the quantity (X-L/X), and neck seals hermetically bonding said inleads to said envelope and subtending less than 7 percent of the solid angle at the center of said arc chamber.

Claim 10

A high pressure metal vapor arc discharge lamp for general illuminating purposes and rated for a power input of not more than 70 watts, said lamp comprising an arc chamber having a substantially ellipsoidal shape and having a volume of less than one cubic centimeter, said arc chamber being defined within an envelope made of fused silica and having a wall thickness not exceeding 1.5 millimeters, a fill of mercury and metal halide contained within said chamber and adapted to be vaporized during operation of the lamp, said arc chamber having a wall area of such value as to effect a wall loading in the range of from about 15 to 35 watts/cm 2 when the lamp is operated at rated wattage, said arc chamber having a length-to-diameter ratio (X/D) in the range of from about 1.5 to 2.5, the entire internal and external surfaces of said envelope being free of heat-conserving coatings, a pair of electrodes supported within said arc chamber on inleads extending through said envelope, said electrodes having opposing tips spaced from one another by a distance L of such value as to effect an arc loading in the range of from about 60 to 120 watts/cm when the lamp is operated at rated wattage, the insertion factor Y of said electrodes being in the range of from about 0.1 to 0.6, where Y is equal to the quantity (X-L/X), and neck seals hermetically bonding said inleads to said envelope and subtending less than 7 percent of the solid angle at the center of said arc chamber.