Patent US2129557A successfully refreshed from Google Patents.
Patent US97806A successfully refreshed from Google Patents.
US3894902A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photoflash lamp and method of coating same
Assignee: GTE Sylvania Inc
•
Filing: 1973-09-04
•
Granted: 1975-07-15
•
Expires: 1993-09-04
Abstract
Abstract A photoflash lamp having a vacuum-formed thermoplastic coating for reinforcing the glass envelope of the lamp and enhancing its containment capability upon flashing. Also, a method for applying the coating comprising: locating the glass envelope in a dried, preformed sleeve of thermoplastic material; drawing a vacuum in the space between the sleeve and the envelope; heating the assembly incrementally lengthwise to gradually form the sleeve onto the envelope; and then constricting and tipping off the sleeve at the conclusion of the heating process.
Inventors
- 👤 Harold L Hough
- 👤 Emery G Audesse
- 👤 Thomas J Sentementes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:56
CPC Classifications
F; F21; F21K; F21K5/00; F21K5/02
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
125 words
A method of coating the glass envelope of a photoflash lamp with a light-transmitting thermoplastic material, said method comprising: placing said glass envelope within a preformed sleeve of said thermoplastic material, and drawing a vacuum in the space between said thermoplastic sleeve and said glass envelope, while simultaneously heating said sleeve and envelope assembly incrementally along the length-thereof so that the temperature and vacuum cause said thermoplastic sleeve to be incrementally formed with a substantially uniform thickness onto the entire exterior surface of said glass envelope with the interface therebetween substantially free of voids, inclusions and the like, whereby after cooling, said thermoplastic coating exerts a compressive load on said glass envelope and a stronger envelope structure is obtained for providing improved containment during flashing.
Claim 2
Independent Claim
125 words
A method of coating the glass envelope of a photoflash lamp with a light-transmitting thermoplastic material, said method comprising: placing said glass envelope within a preformed sleeve of said thermoplastic material, and drawing a vacuum in the space between said thermoplastic sleeve and said glass envelope, while simultaneously heating said sleeve and envelope assembly incrementally along the length-thereof so that the temperature and vacuum cause said thermoplastic sleeve to be incrementally formed with a substantially uniform thickness onto the entire exterior surface of said glass envelope with the interface therebetween substantially free of voids, inclusions and the like, whereby after cooling, said thermoplastic coating exerts a compressive load on said glass envelope and a stronger envelope structure is obtained for providing improved containment during flashing.
Claim 3
Dependent Claim
46 words
The method of claim 1 wherein heat is applied uniformly about sAid sleeve and envelope assembly by one or more localized sources of heat encircling said assembly, and a relative incremental axial movement is effected between said assembly and said one or more sources of heat.
Claim 4
Dependent Claim
55 words
The method of claim 1 wherein heat is applied uniformly about said sleeve and envelope assembly by one or more localized sources of heat encircling said assembly, and said assembly is indexed through a plurality of heating stations, each of which has said one or more localized sources of heat positioned at successively higher elevations.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein the heating of said sleeve and envelope assembly is controlled to bring said thermoplastic sleeve to approximately the softening temperature thereof.
Claim 6
Dependent Claim
28 words
The method of claim 1 including the further step of prebaking said thermoplastic sleeve to remove the moisture therefrom prior to assembling said sleeve with said glass envelope.
Claim 7
Dependent Claim
24 words
The method of claim 5 wherein said prebaking of the sleeve is conducted at a temperature of about 125*C for at least 15 minutes.
Claim 8
Dependent Claim
25 words
The method of claim 1 including the further steps of constricting and tipping off said vacuum-formed sleeve at the conclusion of said incremental heating process.
Claim 9
Dependent Claim
64 words
The method of claim 1 wherein both said thermoplastic sleeve and said glass envelope have generally tubular sidewalls, and the outside diameter of said tubular envelope and inside diameter of said tubular sleeve are dimensioned so that, when said envelope is placed within said sleeve, there exists a clearance of from about 0.001 to 0.010 inch between the tubular sidewalls thereof prior to heating.
Claim 10
Dependent Claim
66 words
The method of claim 1 wherein said lamp has at least one metallic member depending from said glass envelope, said preformed thermoplastic sleeve is shaped like a test tube having at least one hole in the bottom thereof, and in said step of placing said glass envelope within said sleeve, said metallic member is inserted through said hole to thereby project outside said test tube-shaped sleeve.
Claim 11
Dependent Claim
62 words
The method of claim 9 wherein said vacuum is drawn at the open end of said test tube-shaped sleeve opposite the end through which said metallic member projects, and said incremental heating of said assembly proceeds from the end of said sleeve through which said metallic member projects toward the open end of said sleeve from which said vacuum is being drawn.
Claim 12
Dependent Claim
29 words
The method of claim 10 wherein said envelope and sleeve assembly is held during said evacuating and heating processes by means of a chuck gripping said projecting metallic member.
Claim 13
Dependent Claim
28 words
The method of claim 11 wherein said photoflash lamp is a percussive-type, and said metallic member comprises a primer tube coaxially projecting from one end of said envelope.
Claim 14
Dependent Claim
32 words
The method of claim 1 wherein the coefficient of thermal expansion of said thermoplastic sleeve is at least about six times greater than the coefficient of thermal expansion of said glass envelope.
Claim 15
Dependent Claim
35 words
The method of claim 1 wherein the composition of said sleeve comprises a light-transmitting thermoplastic selected from the group consisting of acrylic, acrylonitrilebutadiene-styrene, cellulose acetate, ionomers, methylpentene polymer, nylon, polycarbonate, polystyrene, polysulfone, and alloys thereof.
Claim 16
Dependent Claim
18 words
The method of claim 14 wherein the composition of said sleeve further includes a small amount of plasticizer.
Claim 17
Dependent Claim
13 words
The method of claim 1 wherein said thermoplastic sleeve comprises a polycarbonate resin.
Claim 18
Dependent Claim
16 words
The method of claim 16 wherein the thickness of said polycarbonate sleeve is about 0.020 inch.
Claim 19
Dependent Claim
136 words
The method of claim 10 wherein: both said sleeve and said envelope have generally tubular sidewalls; the outside diameter of said tubular envelope and the inside diameter of said tubular sleeve are dimensioned so that, when said envelope is placed within said sleeve, there exists a clearance of from about 0.001 to 0.010 inch between the tubular sidewalls thereof prior to heating; and the heating of said sleeve and envelope assembly is controlled to bring said thermoplastic sleeve to approximately the softening temperature thereof; and including the further steps of prebaking said thermoplastic sleeve at a temperature of about 125*C for at least 15 minutes to remove the moisture therefrom prior to assembling said sleeve with said glass envelope, and constricting and tipping off said vacuum formed sleeve at the conclusion of said incremental heating process.
Claim 20
Independent Claim
50 words
A METHOD OF COATING THE GLASS ENVELOPE OF A PHOTOFLASH LAMP WITH A LIGHT-TRANSMITTING THERMOPLASTIC MATERIAL, SAID METHOD COMPRISING: PLACING SAID GLASS ENVELOPE WITHIN A PREFORMED SLEEVE OF SAID THERMOPLASTIC MATERIAL, AND FORMING SAID SLEEVE WITH A SUBSTANTIALLY UNIFORM THICKNESS ONTO THE ENTIRE EXERIOR SURFACE OF SAID GLASS ENVELOPE BY
Claim 21
Independent Claim
50 words
A METHOD OF COATING THE GLASS ENVELOPE OF A PHOTOFLASH LAMP WITH A LIGHT-TRANSMITTING THERMOPLASTIC MATERIAL, SAID METHOD COMPRISING: PLACING SAID GLASS ENVELOPE WITHIN A PREFORMED SLEEVE OF SAID THERMOPLASTIC MATERIAL, AND FORMING SAID SLEEVE WITH A SUBSTANTIALLY UNIFORM THICKNESS ONTO THE ENTIRE EXERIOR SURFACE OF SAID GLASS ENVELOPE BY
Claim 22
Dependent Claim
28 words
The method of claim 19 including the further step of prebaking said thermoplastic sleeve to remove the moisture therefrom prior to assembling said sleeve with said glass envelope.
Claim 23
Dependent Claim
24 words
The method of claim 20 wherein said prebaking of the sleeve is conducted at a temperature of about 125*C for at least 15 minutes.
Claim 24
Dependent Claim
24 words
The method of claim 19 including the further steps of constricting and tipping off said formed sleeve at the conclusion of said forming process.
Claim 25
Dependent Claim
17 words
The method of claim 19 wherein both said thermoplastic sleeve and glass envelope have generally tubular sidewalls.
Claim 26
Dependent Claim
67 words
The method of claim 19 wherein said lamp has at least one metallic member depending from said glass envelope, said preformed thermoplastic sleeve is shaped like a test tube having at least one hole in the bottom thereof, and in said step of placing said glass envelope within said sleeve, said metallic member is inserted through said hole to thereby project outside said test tube shaped sleeve.
Claim 27
Dependent Claim
45 words
The method of claim 24 wherein the heating of said test-tube shaped sleeve starts at the end thereof through which said metallic member projects and proceeds toward the open end of the sleeve, and said vacuum is drawn at said open end of the sleeve.
References Cited (Backward Citations)
US3313084A
Cited
US3470046A
Cited
US3454443A
Cited
US3463059A
Cited
US3514081A
Cited
US3551258A
Cited
US3689339A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |