Coating processes – Electrical product produced – Fluorescent or phosphorescent base coating
Patent
1994-07-06
1997-11-11
Beck, Shrive
Coating processes
Electrical product produced
Fluorescent or phosphorescent base coating
427 67, 427157, 427231, 427232, 427165, 118 56, 118500, B05D 506, B05C 1300
Patent
active
056861346
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention concerns a inner surface of meandrous one-tube glass vessels with a suspension, and a device for performing the process.
By "meandrous" or "in a meandrous shape" is meant, with respect to the invention, folded into a continuously connected U-shape.
BACKGROUND OF THE INVENTION
Low-pressure discharge lamps, in particular fluorescent lamps, are widely used for electric lighting. In comparison with incandescent lights, these lamps are characterized by greater lighting efficiency and a longer useful life.
The production of light using low-pressure discharge lamps is achieved through the process of a gas discharge in a discharge vessel: electrons, accelerated in an electric field, collide with and energize gas atoms, which after a short time give up this additional energy in the form of ultra-violet rays; these rays then are transformed into visible light, by passing through a luminous substance applied to the inner walls of the discharge vessel.
Processes are known for applying a luminous substance to the inner surfaces of known discharge vessels, made either of rod-shaped or U-shaped glass tubing. The known processes follow the principle of "fill and dry", or "fill, invert and dry" wherein a suspension is introduced into a discharge vessel, as a spray or under pneumatic pressure. This procedure is known as coating of the discharge vessel. When the discharge vessel is subsequently inverted, excess quantities of the suspension can flow back out of the discharge vessel in a natural way. This stage is followed by a drying procedure.
The kind of process just described is sufficient for discharge vessels that have a simple geometric shape.
Fluorescent lamps that, in contrast to the usual rod-shaped kind, are characterized by a bent discharge vessel and are thus of small dimensions, are known as compact lamps.
With the known compact lamps, the discharge vessel is produced by aligning two or more U-shaped tubes, so that two U-shaped tubes are connected to each other via a hollow coupling at one or other of their legs. This type of discharge vessel can not be coated as a whole using the "fill, invert and dry" process. Instead, the individual U-tubes are coated before they are assembled into the discharge vessel. Consequently the hollow connection devices for the U-tubes, that are affixed only after the coating procedure, receive no, or minimal, coating of the luminous substance and is considered unsatisfactory.
One-tube glass vessels in meandrous form are the subject of German Patent Application P 41 19 852.2, "Process and device for producing one-tube glass vessels in meandrous form", as well as German Patent Application P 42 14 542.2 "Multiple-folded one-tube glass vessels and device and process for their manufacture", from the present applicant. These documents describe multiple-folded one-tube glass vessels with at least four straight parts arranged parallel to each other, and connected to each other by U-shaped sections, with their two open tube ends lying beside each other.
Such vessels are particularly well-suited as discharge vessels for compact lamps. They are characterized, in contrast to the known discharge vessels for compact lamps, by the essentially constant thickness of their walls and an essentially continuous constant cross-section, i.e. they have no constrictions and no dead space.
There is no known process for applying a uniform suspension coating to the inner walls of one-tube glass vessels of meandrous shape.
As mentioned previously, it is not practical to apply a uniform and defect-free coating to a meandrous one-tube glass vessel using the "fill, invert and dry" principle. The process of filling or draining the one-tube glass vessel with the suspension would create eddies in the bends or the legs that would cause disruptive air bubbles. Suspensions are difficult to handle because of their chemical and physical properties; they are thus readily inclined to forming blisters and streaks. A uniform coating requires a continuously eddy-free deposit of the suspe
REFERENCES:
patent: 2650884 (1953-09-01), Pakswer et al.
patent: 2828216 (1958-03-01), Delriew
patent: 3068114 (1962-12-01), Ranby et al.
patent: 3372053 (1968-03-01), McCarthy
patent: 3445266 (1969-05-01), Wittman
patent: 4597984 (1986-07-01), Jansma
Peintures-Pigments-Vernis, Bd. 44, Nr. 1, Jan. 1965; Seite 65, `Examples de Travaux: Paint Technology, 1975, vol. 31, No. 11, p. 55`.
Bernicke Erhard
Dame Jurgen
Munchhausen Rainer
Bareford Katherine A.
Beck Shrive
Prolux Maschinenbau GmbH
LandOfFree
Process and device for coating the inner surface of glass tubes does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process and device for coating the inner surface of glass tubes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process and device for coating the inner surface of glass tubes will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1227009