[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

US2956372A - Tipping-off method - Google Patents

Tipping-off method Download PDF

Info

Publication number
US2956372A
US2956372A US659130A US65913057A US2956372A US 2956372 A US2956372 A US 2956372A US 659130 A US659130 A US 659130A US 65913057 A US65913057 A US 65913057A US 2956372 A US2956372 A US 2956372A
Authority
US
United States
Prior art keywords
tubulation
bubble
wall
exhaust
zone
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US659130A
Inventor
William R Madigan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CBS Corp
Original Assignee
Westinghouse Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Priority to US659130A priority Critical patent/US2956372A/en
Application granted granted Critical
Publication of US2956372A publication Critical patent/US2956372A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/40Closing vessels

Definitions

  • the present invention relates to a method of sealing evacuated discharge and incandescent lamps and, more particularly, to a method of tipping-oil? the exhaust tubulation of said exhausted lamps.
  • the exhaust tubulation of evacuated discharge lamps such as for example fluorescent lamps
  • evacuated discharge lamps such as for example fluorescent lamps
  • C. E. Bechard which method comprises difierentially heating opposite sides of the exhaust tubulation to 01m a bubble within the tubulation thereby closing off the tubulation.
  • the formation of the bubble is accomplished by heating a larger area of one side of the tubulation with greater intensity than the opposite side thereof.
  • This method of differential heating of the exhaust tubulation by burners limits the proximity of the tipofl3 to the lamp seal.
  • the burner fires often undesirably heat and resultantly strain the seal which strain may subsequently result in a cracked seal thus producing a defective lamp.
  • due to drafts around the exhaust head it is extremely difficult to control the fire splash pattern on the opposite sides of the exhaust tubulation, to form the bubble at a desired point. While an increase in the pressure of the gas-air mixture in the burners will pin-point the fire pattern on the tubulation at the desired point, it may result in a change in the temperature of the fires or result in back firing, i.e. an explosion within the gas line which ruptures the line.
  • the bubble forming fire is too sharp a thin bubble is formed within the tubulation and the tire follows the retreating wall of the bubble with resultant further heating and further undesirable thinning of the wall therein.
  • a specific object of the present invention is the provision of a method of tipping-off an exhaust tubulation of an evacuated discharge lamp which method prevents any undesirable thinning of the wall of the bubble during formation thereof.
  • Fig. 1 is a side elevational view of a portion of an exhaust head in which a discharge device such as a fluorescent lamp is secured by its exhaust tubulation and showing a heat bafile for protecting the seal and lead wires, the burners and the air nozzle positioned about the tubulation.
  • a discharge device such as a fluorescent lamp
  • Fig. 2 is an enlarged plan view along the line IIII of Fig. 1 in the direction of the arrows.
  • Fig. 3 is an enlarged vertical sectional view of a portion of the exhaust tubulation illustrating the preliminary phase of the tip-oft method wherein the walls of the tubulation above the bubble are commencing to collapse and the bubble is beginning to form.
  • Fig. 4 is a vertical sectional view along the line IV-IV of Fig. 3 in the direction of the arrows.
  • Fig. 5 is a horizontal sectional view along the line V-V of Fig. 3 in the direction of the arrows.
  • Fig. 6 is a view similar to Fig. 3 but showing an intermediate step in the forming of the bubble in the converging wall of the tubulation.
  • Figs. 7 and 8 are side elevational views of the finished tip-oft and showing the spherical dome of the bubble.
  • an electric lamp 10 such as a fluorescent lamp
  • an exhaust tubulation 12 of the type shown in U.S. Patent No. 2,254,905, issued September 2, 1941, to D. Mullan, which head 14 may be part of an exhaust machine of the type shown in U.S. Patent No. 2,247,513, issued July 1, 1941, to A. J. Marshaus.
  • the exhaust tubulation 12 connects the interior of the lamp 10 with the exhaust head 14 to permit the evacuation and exhaust of the lamp 1!).
  • a pair of identical tipping-ofi burners 2-2 are disposed in the same horizontal plane on opposite sides of the exhaust tubulation 12.
  • an air nozzle 24 is disposed for convenience at right angles to the burners 22 and in the same horizontal plane as the burners 22.
  • the air nozzle 24 continuously directs a circular jet of compressed air at room temperature, under a pressure of about 7 lbs. per square inch, which air jet has a diameter comparable to the desired diameter of the opening of a bubble 26, at a predetermined area B in the zone A.
  • the zone A of the exhaust tubulation 12 is uniformly heated by the burners 22 to the plastic condition to enable the atmospheric pressure to cause a uniform collapse inwardly of the wall of the tubulation, as shown in Figs. 3, 4 and 5.
  • a uniform collapse inwardly of the wall of the tubulation as shown in Figs. 3, 4 and 5.
  • the jet of compressed air from the nozzle 24 directed at the area B begins to drive the wall of the exhaust tubulation thereat inwardly to join the glass at the opposite side wall and such air jet simultaneously cools the wall on the forming bubble 26 to prevent undue thinning or weakening thereof.
  • the lamp is pulled downwardly by a mechanism (not shown) which carries the heat baffie 25) to stretch and thin the collapsing wall at point C of Fig. 6.
  • a mechanism not shown
  • the heat baffie 25 to stretch and thin the collapsing wall at point C of Fig. 6.
  • Continued heating of the zone A by the burners 22 moves the collapsing side wall of the exhaust tubulation 12 thereat from the position shown in Fig. 6 to the position shown in Fig. 7 to sever the tubulation 12 and produce the resultant spherically shaped tip shown in Figs. 7 and 8, which tip is desirably about 1 mm. shorter than the tip shown in the above mentioned US. Patent No' 2,56
  • the method of tipping-off a vitreous exhaust tubulation protruding from an evacuated device which comprises uniformly heating a zone of the exhaust tubulation to cause the wall thereof to collapse inwardly, directing a jet of a fluid at a predetermined area in said heated zone to cause said area to be driven into said tubulation to join with the opposite wall thereof and to form a bubble thereby closing off the tubulation and cooling it to prevent undue thinning of the wall of said bubble, and continuing the heating of said zone to sever the collapsing wall of said tubulation and to form a dome for said bubble.
  • a vitreous exhaust tubulation protruding from an evacuated device having a seal which comprises shielding the seal of said device from heat, uniformly heating a zone of the exhaust tubulation to cause the wall thereof to collapse inwardly, directing a jet of a fluid at a predetermined area in said heated zone to cause said area to be driven into said tubulation to join with the opposite wall thereof and to form a bubble thereby closing off the tubulation and cooling it to prevent undue thinning of the wall of said bubble, and continuing the heating of said zone to sever the collapsing Wall of said tubulation and to form a dome for said bubble.
  • the method of tipping-off a vitreous exhaust tubulation protruding from an evacuated lamp having a seal which comprises shielding the seal of said lamp from heat, heating uniformly a zone of the exhaust tubulation to cause the heated wall thereof to collapse inwardly, directing a jet of cooling air at a pressure of about seven pounds per square inch and of a preselected cross-sectional area at a predetermined area in said heated zone to cause said predetermined area to be driven into said tubulation to join with the opposite wall thereof and to form a bubble thereby closing ofi the tubulation and cooling it to prevent undue thinning of the wall of said bubble and simultaneously stretching the collapsing zone of said tubulation longitudinally to thin the wall thereof while continuing the heating of said zone to sever the collapsing wall of said tubulation and to form a generally spherical dome for said bubble.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)

Description

Oct. 18, 1960 w. R. MADIGAN TIPPING-OFF METHOD Filed May 14, 1957 INVENTOR. WILLIAM F5. MADIGAN FUTORNEY.
United States Patent 'ice TIPPlNG-OFF METHOD William R. Madigan, Fairmont, W. Van, assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa, a corporation of Pennsylvania Filed May 14, 1957, Ser. No. 659,130
6 Claims. (CI. 4978) The present invention relates to a method of sealing evacuated discharge and incandescent lamps and, more particularly, to a method of tipping-oil? the exhaust tubulation of said exhausted lamps.
In the tipping-ofi of evacuated discharge lamps, such as for example fluorescent lamps, it is extremely desirable to form the tip-off on the exhaust tubulation as close to the lamp seal as possible to protect the tip-ofi from contact with the base which is applied about the seal and tip-oil dtuing the later basing operation.
Heretofore, the exhaust tubulation of evacuated discharge lamps, such as for example fluorescent lamps, have been tipped-oft by the method disclosed in U.S. Patent No. 2,561,838, issued July 24, 1951, to C. E. Bechard, which method comprises difierentially heating opposite sides of the exhaust tubulation to 01m a bubble within the tubulation thereby closing off the tubulation. The formation of the bubble is accomplished by heating a larger area of one side of the tubulation with greater intensity than the opposite side thereof. This method of differential heating of the exhaust tubulation by burners limits the proximity of the tipofl3 to the lamp seal. If the tip-off is desirably achieved close to the lamp seal, the burner fires often undesirably heat and resultantly strain the seal which strain may subsequently result in a cracked seal thus producing a defective lamp. Further, due to drafts around the exhaust head it is extremely difficult to control the fire splash pattern on the opposite sides of the exhaust tubulation, to form the bubble at a desired point. While an increase in the pressure of the gas-air mixture in the burners will pin-point the fire pattern on the tubulation at the desired point, it may result in a change in the temperature of the fires or result in back firing, i.e. an explosion within the gas line which ruptures the line. In addition, if the bubble forming fire is too sharp a thin bubble is formed within the tubulation and the tire follows the retreating wall of the bubble with resultant further heating and further undesirable thinning of the wall therein.
It is the general object of the present invention to avoid the foregoing and other ditficulties of and objections to the prior art practices by the provision of a method of formin a bubble-type tip-off in the exhaust tubulation of an evacuated device, such as a discharge or incandescent lamp, which method provides positive control over the location of the bubble formed in the exhaust tubulation and permits its formation close to the lamp seal without dmaging the seal.
A specific object of the present invention is the provision of a method of tipping-off an exhaust tubulation of an evacuated discharge lamp which method prevents any undesirable thinning of the wall of the bubble during formation thereof.
The aforesaid objects of the invention, and other objects which will become apparent as the description proceeds are achieved by providing a method of tippingoff the exhaust tubulation of an evacuated device which method comprises heating a Zone of the exhaust tubula- Patented Oct. 18, 1960 tion to a plastic condition to cause the sides of the tubulation to suck in and directing a jet of predetermined pressure and direction against a predetermined point in the heated zone to form a bubble and simultaneously cool the wall of the forming bubble to prevent further thinning thereof.
Referring to the accompanying drawing in which like numerals of reference indicate similar parts throughout the several views:
Fig. 1 is a side elevational view of a portion of an exhaust head in which a discharge device such as a fluorescent lamp is secured by its exhaust tubulation and showing a heat bafile for protecting the seal and lead wires, the burners and the air nozzle positioned about the tubulation.
Fig. 2 is an enlarged plan view along the line IIII of Fig. 1 in the direction of the arrows.
Fig. 3 is an enlarged vertical sectional view of a portion of the exhaust tubulation illustrating the preliminary phase of the tip-oft method wherein the walls of the tubulation above the bubble are commencing to collapse and the bubble is beginning to form.
Fig. 4 is a vertical sectional view along the line IV-IV of Fig. 3 in the direction of the arrows.
Fig. 5 is a horizontal sectional view along the line V-V of Fig. 3 in the direction of the arrows.
Fig. 6 is a view similar to Fig. 3 but showing an intermediate step in the forming of the bubble in the converging wall of the tubulation.
Figs. 7 and 8 are side elevational views of the finished tip-oft and showing the spherical dome of the bubble.
Although the principles of the invention are broadly applicable to a method for tipping-0E an evacuated device, such as a discharge or incandescent lamp, the invention is particularly adapted to the tipping-off of fluorescent lamps and hence it has been illustrated and will be so described.
With specific reference to the form of the invention illustrated in the drawings there is shown in Fig. 1, an electric lamp 10, such as a fluorescent lamp, secured by means of its exhaust tubulation 12 in an exhaust head 14 of the type shown in U.S. Patent No. 2,254,905, issued September 2, 1941, to D. Mullan, which head 14 may be part of an exhaust machine of the type shown in U.S. Patent No. 2,247,513, issued July 1, 1941, to A. J. Marshaus. As is well known in the art, the exhaust tubulation 12 connects the interior of the lamp 10 with the exhaust head 14 to permit the evacuation and exhaust of the lamp 1!). In order to protect a seal 16 and lead wires 18 of the lamp 1% during the tipping-off operation, a conically shaped heat bafile 2d of the type shown in the above mentioned U.S. Patent No. 2,247,513 is shown in the operating position.
For the purpose of uniformly plasticizing a zone A (Fig. 3) of the exhaust tubulation 12 in the desired location where the bubble is to be formed, a pair of identical tipping-ofi burners 2-2 are disposed in the same horizontal plane on opposite sides of the exhaust tubulation 12. To provide a bubble forming control means for use, as hereinafter related, an air nozzle 24 is disposed for convenience at right angles to the burners 22 and in the same horizontal plane as the burners 22. The air nozzle 24 continuously directs a circular jet of compressed air at room temperature, under a pressure of about 7 lbs. per square inch, which air jet has a diameter comparable to the desired diameter of the opening of a bubble 26, at a predetermined area B in the zone A.
In accordance with the present invention after the lamp 10 has been evacuated in the usual manner through the exhaust tubulation 12 and filled with a predetermined amount of mercury and an inert gas, such as argon, the zone A of the exhaust tubulation 12 is uniformly heated by the burners 22 to the plastic condition to enable the atmospheric pressure to cause a uniform collapse inwardly of the wall of the tubulation, as shown in Figs. 3, 4 and 5. During this inward collapse. of the wall from the position shown in Figs. 1 and 2 to the position shown in Figs. 3, 4 and 5, the jet of compressed air from the nozzle 24 directed at the area B begins to drive the wall of the exhaust tubulation thereat inwardly to join the glass at the opposite side wall and such air jet simultaneously cools the wall on the forming bubble 26 to prevent undue thinning or weakening thereof. Simultaneously, with the formation of the bubble 26 the lamp is pulled downwardly by a mechanism (not shown) which carries the heat baffie 25) to stretch and thin the collapsing wall at point C of Fig. 6. Continued heating of the zone A by the burners 22. moves the collapsing side wall of the exhaust tubulation 12 thereat from the position shown in Fig. 6 to the position shown in Fig. 7 to sever the tubulation 12 and produce the resultant spherically shaped tip shown in Figs. 7 and 8, which tip is desirably about 1 mm. shorter than the tip shown in the above mentioned US. Patent No' 2,561,838.
. It will thus be obvious to those skilled in the art that a method of tipping-off an exhaust tubulation of an evacuated lamp has been provided which achieves positive control over the location of the bubble which is formed in the exhaust tubulation and permits the formation of the bubble close to the lamp seal without damaging the latter. In addition, the tip-oi method of the present invention prevents any undue thinning or weakening of the wall of the bubble during the formation thereof.
While in accordance with the patent statutes, one bestknown embodiment of the invention has been illustrated and described in detail, it is to be particularly understood that the invention is not limited thereto or thereby.
I claim:
1. The method of tipping-off a vitreous exhaust tubulation protruding from an evacuated device which comprises uniformly heating a zone of the exhaust tubulation to cause the wall thereof to collapse inwardly, directing a jet of a fluid at a predetermined area in said heated zone to cause said area to be driven into said tubulation to join with the opposite wall thereof and to form a bubble thereby closing off the tubulation and cooling it to prevent undue thinning of the wall of said bubble, and continuing the heating of said zone to sever the collapsing wall of said tubulation and to form a dome for said bubble.
2. The method of tipping-01f a vitreous exhaust tubulation protruding from an evacuated device having a seal which comprises shielding the seal of said device from heat, uniformly heating a zone of the exhaust tubulation to cause the wall thereof to collapse inwardly, directing a jet of a fluid at a predetermined area in said heated zone to cause said area to be driven into said tubulation to join with the opposite wall thereof and to form a bubble thereby closing off the tubulation and cooling it to prevent undue thinning of the wall of said bubble, and continuing the heating of said zone to sever the collapsing Wall of said tubulation and to form a dome for said bubble.
3. The method of tipping-01f a vitreous exhaust tubulation protruding from an evacuated lamp having a seal which comprises shielding the seal of said lamp from heat, uniformly heating a zone of the exhaust tubulation to cause the wall thereof to collapse inwardly, directing a jet of a fluid at a predetermined area in said heated zone to cause said area to be driven into said tubulation to join with the opposite wall thereof and to form a bubble thereby closing off the tubulation and cooling it to prevent undue thinning of the wall of said bubble and simultaneously stretching the collapsing zone of said tubulation longitudinally to thin the wall thereof While continuing the heating of said zone to sever the collapsing wall of said tubulation and to form a dome for said bubble.
4. The method of tipping-off a vitreous exhaust tubulation protruding from an evacuated lamp which comprises uniformly heating a zone of the exhaust tubulation to cause the heated wall thereof to collapse inwardly, directing a jet of cooling air at a pressure of about seven pounds per square inch and of a preselected cross-sectional area at a predetermined area in said heated zone to cause said predetermined area to be driven into said tubulation to join with the opposite wall thereof and to form a bubble thereby closing oif the tubulation and cooling it to prevent undue thinning of the wall of said bubble and continuing the heating of said zone to sever the collapsing wall of said tubulation and to form a dome for said bubble.
5. The method of tipping-off a vitreous exhaust tubulation protruding from an evacuated lamp having a seal which comprises shielding the seal of said lamp from heat, heating uniformly a zone of the exhaust tubulation to cause the heated wall thereof to collapse inwardly, directing a jet of cooling air at a pressure of about seven pounds per square inch and of a preselected cross-sectional area at a predetermined area in said heated zone to cause said predetermined area to be driven into said tubulation to join with the opposite wall thereof and to form a bubble thereby closing ofi the tubulation and cooling it to prevent undue thinning of the wall of said bubble and simultaneously stretching the collapsing zone of said tubulation longitudinally to thin the wall thereof while continuing the heating of said zone to sever the collapsing wall of said tubulation and to form a generally spherical dome for said bubble.
6. The method of tipping-off a vitreous exhaust tubulation protruding from an evacuated device which comprises heating opposite sides of a zone of the exhaust tubulation to cause the wall thereof to collapse inwardly, direction a jet of a fluid transverse to the application of heat and at a predetermined area in said heated zone to cause said area to be driven into said tubulation to join with the opposite wall thereof and to form a bubble thereby closing off the tubulation and cooling it to prevent undue thinning of the wall of said bubble, and continuing the heating of said zone to sever the collapsing wall of said tubulation and to form a dome for said bubble.
References Cited in the file of this patent UNITED STATES PATENTS Howard July 12, 1927
US659130A 1957-05-14 1957-05-14 Tipping-off method Expired - Lifetime US2956372A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US659130A US2956372A (en) 1957-05-14 1957-05-14 Tipping-off method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US659130A US2956372A (en) 1957-05-14 1957-05-14 Tipping-off method

Publications (1)

Publication Number Publication Date
US2956372A true US2956372A (en) 1960-10-18

Family

ID=24644163

Family Applications (1)

Application Number Title Priority Date Filing Date
US659130A Expired - Lifetime US2956372A (en) 1957-05-14 1957-05-14 Tipping-off method

Country Status (1)

Country Link
US (1) US2956372A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3189423A (en) * 1962-01-15 1965-06-15 Paragon Glass Works Inc Glass bulb cut off method
US3313610A (en) * 1964-07-09 1967-04-11 Westinghouse Electric Corp Method of tipping-off exhaust tubing
US3320012A (en) * 1965-06-29 1967-05-16 Gen Electric Method of manufacturing photoflash lamps
US4465501A (en) * 1981-11-05 1984-08-14 Millipore S.A. Apparatus for aseptic and antiparticulate opening of sealed glass containers

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1635716A (en) * 1925-09-29 1927-07-12 Hartford Empire Co Method and apparatus for blowing glass parisons
US2561838A (en) * 1949-10-28 1951-07-24 Gen Electric Tipping-off method

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1635716A (en) * 1925-09-29 1927-07-12 Hartford Empire Co Method and apparatus for blowing glass parisons
US2561838A (en) * 1949-10-28 1951-07-24 Gen Electric Tipping-off method

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3189423A (en) * 1962-01-15 1965-06-15 Paragon Glass Works Inc Glass bulb cut off method
US3313610A (en) * 1964-07-09 1967-04-11 Westinghouse Electric Corp Method of tipping-off exhaust tubing
US3320012A (en) * 1965-06-29 1967-05-16 Gen Electric Method of manufacturing photoflash lamps
US4465501A (en) * 1981-11-05 1984-08-14 Millipore S.A. Apparatus for aseptic and antiparticulate opening of sealed glass containers

Similar Documents

Publication Publication Date Title
US2417361A (en) Apparatus for producing cold cathode fluorescent lamps or the like
US2956372A (en) Tipping-off method
US1461155A (en) Method of and apparatus for manufacturing incandescent lamps
US2711055A (en) Method of reshaping tubular stock
US2561838A (en) Tipping-off method
US2716584A (en) Double hermetic seal for gaseous discharge lamps
US2391572A (en) Method for producing electronic devices
US2401638A (en) Method of vacuum sealing
US4561874A (en) Method for heat sealing a gun mount in a CRT neck
US2215100A (en) Method and machine for sealing vitreous vessels
US2014471A (en) Process of sealing-off vessels containing gas
US3313610A (en) Method of tipping-off exhaust tubing
US2359500A (en) Sealing-in method
GB486872A (en) Improvements in or relating to electric incandescent lamps and discharge apparatus
US2359501A (en) Sealing-in apparatus
US1653378A (en) Method of making bimetallic wire
US1945769A (en) Method of sealing off
US2694273A (en) Method of tipless sealing of vitreous envelopes
US4000997A (en) Method for reducing thermally induced fracture in cathode ray tube bulbs
US3240861A (en) Panel lamp seal
US2570683A (en) Lead wire construction and method of sealing
US3188162A (en) Method of making flash lamps
US2284899A (en) Method of making mercury switches
US1701388A (en) Method of and apparatus for sealing-in incandescent lamps and similar articles
US2717475A (en) Method of effecting a glass to metal seal