Method of manufacturing a lamp

A method of manufacturing a metal vapor lamp without resort to an exhaust tube, said method comprising the steps of, providing a lamp body having a hollow bulbous midportion with tubular neck portions projecting in opposite directions therefrom, heating said body while flowing inert dry gas into an upstream neck portion and out the downstream neck portion, and continuing the flow of gas while:

• (a) inserting a first electrode tip last completely through the downstream neck portion and the midportion and into the upstream neck portion so that it remains supported solely by said upstream neck portion,
• (b) inserting a dose of vaporizable material which is solid or liquid at ambient temperature through the downstream neck portion and into the midportion,
• (c) inserting a second electrode tip first into the downstream neck portion so that it remains supported solely by said downstream neck portion at a predetermined spacing from the first electrode,
• the foregoing steps (a), (b) and (c) being performed in a sequence that makes (c) last, and then closing off the downstream neck portion and terminating the flow.

A method of manufacturing a metal halide lamp without resort to an exhaust tube, said method comprising the steps of, providing (i) a lamp body having a hollow bulbous midportion with tubular neck portions projecting in opposite directions therefrom, and (ii) first and second electrode-inlead assemblies each having a tip adapted to be spaced from the tip of the other to define an arc gap therebetween, heating said body while rotating it about the axis of said neck portions and while flowing an inert gas into an upstream neck portion and out the other downstream neck portion, continuing the flow of gas while:

• (a) inserting said first assembly tip last through the downstream neck portion and into the upstream neck portion and positioning said first assembly with its tip projecting a predetermined distance into the midportion, and inserting doses of metal halide and mercury through the downstream neck portion and transporting them upstream against the gas flow into the midportion,
• (b) then inserting said second assembly tip first into the downstream neck portion and positioning said second assembly with its tip located in the midportion and spaced a predetermined distance from the tip of said first assembly,
• thereafter closing off the downstream neck portion thereby terminating the flow, supplying inert dry gas at subatmospheric pressure to said body, cooling said midportion, and heat-sealing the inlead portions of said assemblies into their respective neck portions.

A method of manufacturing a metal halide lamp without resort to an exhaust tube, said method comprising the steps of, providing a pair of spaced and axially aligned rotatable, horizontal chucks each adapted to selectively grip or release a fused silica tube, one of said chucks being adapted to move toward and away from the other, one of said chucks being inboard and having an inboard end selectively communicating with a pressurized source of gas while the other is outboard, inserting a fused silica tube through the outboard end of the outboard chuck to locate it between the chucks, gripping the ends of said tube by both chucks, heating said tube while rotating it and while moving one chuck toward the other to gather material at the midportion of said tube, placing a mold alongside the material gathered at said midportion, inserting a closure into the outboard chuck to temporarily seal the downstream end of said tube from ambient atmosphere, introducing pressurized gas into the upstream end of said tube through said inboard chuck while said tube is being rotated and heated, thereby to blow the material at the midportion of the tube into said mold and form the tube into a lamp body having a bulbous midportion with neck portions projecting in opposite directions therefrom, said method being characterized by the steps of, removing said closure and said mold, heating said lamp body while rotating it and flowing gas therethrough from said source to decontaminate said body, continuing the flow of gas while:

• (a) inserting a first electrode-inlead assembly tip last through the downstream neck portion and into the upstream neck portion and positioning said first assembly with its tip projecting a predetermined distance into the midportion, and inserting doses of metal halide and mercury through the downstream neck portion and into the midportion,
• (b) inserting a second electrode-inlead assembly tip first into the downstream neck portion and positioning said second assembly with its tip located in the midportion and spaced a predetermined distance from the tip of said first assembly, and
• (c) closing off the downstream neck portion, then cooling said midportion, supplying inert dry gas at subatmospheric pressure to said body, and heat-sealing the inlead portions of said assemblies into their respective neck portions.

A method of manufacturing a discharge lamp to achieve precise determination of the electrode gap within a bulb, said method comprising the steps of:

• seizing a tube of vitreous material in a glass lathe,
• while the tube is so seized, making a lamp body out of the tube by forming a hollow bulbous midportion therein with tubular neck portions projecting in opposite directions, said bulbous midportion being precisely located relative to the lathe,
• then, while maintaining the original seizure of the lamp body in the lathe, inserting an electrode into each neck portion, the tips of the electrodes being precisely located relative to the lathe whereby the length of the electrode gap and its location within the bulbous midportion are precisely determined,
• and thereafter sealing said electrodes into their respective neck portions.

A method of manufacturing a discharge lamp to achieve precise determination of the electrode gap within a bulb together with high internal purity, said method comprising the steps of:

• seizing a tube of vitreous material in a glass lathe and heating the midportion of the tube into the softening range while spinning it,
• while the tube is so seized, making a lamp body from it by forming the midportion while in the softening range into a hollow bulb having tubular neck portions projecting in opposite directions therefrom, said bulbous midportion being precisely located relative to the lathe,
• then extending the heating to the entire lamp body while continuing to spin it in the lathe and while flushing it with a nonreactive dry gas in order to remove moisture and other contaminants from the vitreous material at higher temperatures than will be encountered by said body during life after completion into a lamp,
• thereafter without altering the seizure of the lamp body in the lathe and while continuing the flushing, inserting electrodes into said lamp body in such manner that the tips of the electrodes are precisely located relative to the lathe whereby the length of the electrode gap and its location within the bulbous midportion are precisely determined,
• and finally sealing said lamp body and terminating the flushing.