Method of incorporating amalgam-forming material in a fluorescent lamp

Claim 2

IN THE MANUFACTURE OF A LOW-PRESSURE MERCURY VAPOR DISCHARGE LAMP HAVING AN ELECTRODE MOUNT STRUCTURE INCLUDING A VITREOUS STEM SEALED TO AND EXTENDING INWARDLY FROM ONE END OF THE LAMP ENVELOPE, THE MTHOD OF INCORPORATING AN AMALGAM-FORMING MATERIAL AS AN INTEGRAL PART OF THE LAMP AND AT A LOCATION THEREIN SUCH THAT SAID MATERIAL WILL REGULATE THE MERCURY VAPOR PRESSURE WHEN THE LAMP IS OPERATED, SAID METHOD COMPRISING: HEATING A VITREOUS TUBE FROM WHICH SAID STEM IS TO BE MADE TO THE SOFTENING POINT THEREOF, FLARING SAID HEATED STEM TUBE AT ONE END, APPLYING SAID AMALGAM-FORMING MATERIAL ONTO THE EXTERIOR SURFACE OF THE FLARED PORTION OF SAID HEATED STEM TUBE, INSERTING AN EXHAUST TUBE AND LEAD WIRES INTO SAID STEM TUBE, HEATING THE NON-FLARED END OF SAID STEM TUBE TO THE MELTING POINT THEREOF, PRESSING THE NON-FLARED END OF SAID HEATED STEM TUBE TO FUSE SAID EXHAUST TUBE AND LEAD WIRES THEREIN, COMPLETING FABRICATION OF THE ELECTRODE MOUNT STRUCTURE WHICH INCLUDES SAID STEM TUBE, EXHAUST TUBE AND LEAD WIRES, AND ATTACHING SAID MOUNT STRUCTURE TO THE LAMP BY SEALING THE PERIPHERY OF THE FLARED PORTION OF SAID STEM TUBE TO AN END OF SAID LAMP ENVELOPE, AND THEN COMPLETING THE FABRICATION OF THE LAMP.

Claim 3

In the manufacture of a low-pressure mercury vapor discharge lamp having an electrode mount structure including a vitreous stem sealed to and extending inwardly from one end of the lamp envelope, the method of incorporating an amalgam-forming material as an integral part of the lamp and at a location therein such that said material will regulate the mercury vapor pressure when the lamp is operated, said method comprising: heating a vitreous tube from which said stem is to be made to the softening point thereof, flaring said heated stem tube at one end, applying said amalgam-forming material onto the exterior surface of the flared portion of said heated stem tube, inserting an exhaust tube and lead wires into said stem tube, heating the non-flared end of said stem tube to the melting point thereof, pressing the non-flared end of said heated stem tube to fuse said exhaust tube and lead wires therein, completing fabrication of the electrode mount structure which includes said stem tube, exhaust tube and lead wires, and attaching said mount structure to the lamp by sealing the periphery of the flared portion of said stem tube to an end of said lamp envelope, and then completing the fabrication of the lamp.

Claim 4

In the manufacture of a low-pressure mercury vapor discharge lamp having an electrode mount structure including a vitreous stem sealed to and extending inwardly from one end of the lamp envelope, the method of incorporating an amalgam-forming material as an integral part of the lamp and at a location therein such that said material will regulate the mercury vapor pressure when the lamp is operated, said method comprising: heating a vitreous tube from which said stem is to be made to the softening point thereof, flaring said heated stem tube at one end, applying said amalgam-forming material onto the exterior surface of the flared portion of said heated stem tube, inserting an exhaust tube and lead wires into said stem tube, heating the non-flared end of said stem tube to the melting point thereof, pressing the non-flared end of said heated stem tube to fuse said exhaust tube and lead wires therein, completing fabrication of the electrode mount structure which includes said stem tube, exhaust tube and lead wires, and attaching said mount structure to the lamp by sealing the periphery of the flared portion of said stem tube to an end of said lamp envelope, and then completing the fabrication of the lamp.

Claim 5

The method of claim 1 wherein said amalgam-forming material is applied inwardly from the rim of said flared portion while said heated stem tube is being rotated about its longitudinal axis so that said material is deposited in a layer of annular configuration that extends around the circumference of said flared portion.

Claim 6

The method of claim 2 including the further steps of scoring and cutting said rotating stem tube to remove a segment of the non-flared end thereof subsequent to applying the amalgam-forming material and prior to inserting the lead wires and exhaust tube.

Claim 7

The method of claim 2 wherein said amalgam-forming material is applied by feeding a wire thereof onto the heated flared portion of said rotating stem tube.

Claim 8

The method of claim 4 wherein the amalgam-forming material is indium.

Claim 9

The method of claim 1 including the further steps of scoring and cutting said stem tube to remove a segment of the non-flared end thereof subsequent to applying the amalgam-forming material and prior to inserting the lead wires and exhaust tube.

Claim 10

The method of claim 1 wherein said vitreous tube is glass, one of said glass tube is heated to the softening point thereof prior to said flaring stEp, and said amalgam-forming material is indium and is applied inwardly from the rim of said flared portion about the circumference thereof in a layer of annular configuration.

Claim 11

The method of claim 1 wherein said amalgam-forming material is applied by using a powder thereof in a suspension and spraying it onto the heated flare portion of said stem tube.