U.S. patent application number 11/396635 was filed with the patent office on 2006-10-26 for electric lamp having an outer bulb.
This patent application is currently assigned to PATENT-TREUHAND-GESELLSCHAFT FUR ELEKTRISCHE GLUHLAMPEN MBH. Invention is credited to Jurgen Graf.
Application Number | 20060236651 11/396635 |
Document ID | / |
Family ID | 36998977 |
Filed Date | 2006-10-26 |
United States Patent
Application |
20060236651 |
Kind Code |
A1 |
Graf; Jurgen |
October 26, 2006 |
Electric lamp having an outer bulb
Abstract
The lamp comprises a discharge vessel (2), which is sealed in a
vacuum-tight manner and is arranged in an outer bulb (12) which
only partially surrounds the discharge vessel. The outer bulb
comprises an open tube, which is closed by sheet-metal parts.
Inventors: |
Graf; Jurgen; (Augsburg,
DE) |
Correspondence
Address: |
OSRAM SYLVANIA INC
100 ENDICOTT STREET
DANVERS
MA
01923
US
|
Assignee: |
PATENT-TREUHAND-GESELLSCHAFT FUR
ELEKTRISCHE GLUHLAMPEN MBH
MUNCHEN
DE
|
Family ID: |
36998977 |
Appl. No.: |
11/396635 |
Filed: |
April 4, 2006 |
Current U.S.
Class: |
52/750 |
Current CPC
Class: |
H01J 9/247 20130101;
H01K 3/00 20130101; H01J 61/34 20130101; Y02B 20/125 20130101; Y02B
20/00 20130101; H01K 1/34 20130101 |
Class at
Publication: |
052/750 |
International
Class: |
E04B 1/00 20060101
E04B001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 4, 2005 |
JP |
102005015407.7 |
Claims
1. An electric lamp having an outer bulb and having an inner
vessel, in particular a discharge vessel, arranged therein, the
inner vessel being elongate and having two ends, the ends having
seals, and the outer bulb only partially surrounding the inner
vessel, wherein the outer bulb is an open tube made from glass and
having two ends, at least one end being sealed by an essentially
planar sheet-metal part made from resilient sheet metal, the
sheet-metal part being fixed on the associated seal.
2. The lamp as claimed in claim 1, wherein the sheet-metal part is
in the form of a disk, the outer diameter of the disk approximately
corresponding to the outer diameter of the end of the open
tube.
3. The lamp as claimed in claim 2, wherein lugs, which bear on the
inside against the end of the tube are distributed over the
circumference of the outer diameter of the sheet-metal part.
4. The lamp as claimed in claim 2, wherein the sheet-metal part has
a central opening which is matched to the cross section of the
seal.
5. The lamp as claimed in claim 4, wherein the sheet-metal part is
held securely on the seal by the seal being cylindrical with a
given diameter and opening out over one edge into an extension part
which is in the form of an open tube having a relatively large
diameter, the diameter of the central opening of the sheet-metal
part being matched to that of the seal.
6. The lamp as claimed in claim 5, wherein the zone is divided into
a plurality of tabs by means of radially extending slots.
7. The lamp as claimed in claim 3, wherein a clamping action of the
sheet-metal part on the tube is achieved by the lugs being bent out
in the manner of a roof.
8. The lamp as claimed in claim 1, wherein the seal has a circular
cross section and, in particular, represents a fuse seal.
9. The lamp as claimed in claim 1, wherein the outer bulb is kept
air-tight by a sealing ring being introduced in the contact region
between the sheet-metal part and the end of the open tube.
10. The lamp as claimed in claim 1, wherein the inner vessel is
sealed at two mutually opposing ends by means of identical seals,
the outer bulb being fixed to the seals of the inner vessel by
means of two sheet-metal parts.
11. A method for producing a lamp having an outer bulb as claimed
in claim 1, wherein an open tube is pushed centrally over an inner
vessel, and then a sheet-metal part is placed onto the open end of
the tube, the lugs being bent back through approximately
90.degree., and the central opening being selected to be slightly
smaller than the cross section of the associated seal, with the
result that, when it is placed on the seal, the central opening is
enlarged to the diameter of the seal by the individual tabs of the
surrounding zone being bent out slightly from the plane of the
sheet-metal part.
Description
TECHNICAL FIELD
[0001] The invention relates to an electric lamp having an outer
bulb and having an inner vessel, in particular a discharge vessel,
arranged therein, the inner vessel being elongate and having two
ends, the ends having seals, and the outer bulb only partially
surrounding the inner vessel. Of concern here are, in particular,
discharge lamps such as metal halide lamps, or else halogen
incandescent lamps.
BACKGROUND ART
[0002] U.S. Pat. No. 2,004,0253897 has disclosed an electric lamp
having an outer bulb, in the case of which the outer bulb only
partially surrounds the inner vessel made from glass. The outer
bulb is itself produced from glass and is fixed to the seals of the
inner vessel. This partially covering outer bulb could in this case
be fixed using an established technique by means of glass shaping
and subsequent glass-to-glass fusing. However, it has been shown
that these steps overall have relatively stringent requirements in
terms of machine capacity and energy.
DISCLOSURE OF THE INVENTION
[0003] One object of the present invention is to provide an
electric lamp having an outer bulb and having an inner vessel, in
particular a discharge vessel, arranged therein, the inner vessel
being elongate and having two ends, the ends having seals, and the
outer bulb only partially surrounding the inner vessel, which lamp
makes simple and cost-effective production possible.
[0004] This object is achieved by the following features:
the outer bulb is an open tube made from glass and having two ends,
at least one end being sealed by an essentially planar sheet-metal
part made from resilient sheet metal, the sheet-metal part being
fixed on the associated seal.
[0005] Particularly advantageous refinements are described in the
dependent claims.
[0006] The electric lamp according to the invention has an outer
bulb and an inner vessel, usually a discharge vessel, which is
arranged therein and is sealed in a vacuum-tight manner. However,
the electric lamp according to the invention may also be a halogen
incandescent lamp having an outer bulb.
[0007] The novel connection between the inner vessel and the outer
bulb makes possible a purely mechanical mounting system, which is
based on sheet-metal clips. This considerably reduces the machining
complexity and also no longer requires any heating energy. The
novel concept is particularly suitable in cases in which a specific
atmosphere is not required in the outer bulb, for example a vacuum
or a pure nitrogen atmosphere.
[0008] One particularly preferred embodiment, in which the
advantages of the novel concept are particularly prevalent, is an
arrangement in which the outer bulb is sealed by sheet-metal parts
at both mutually opposing ends of the inner vessel. Typical
applications are metal halide lamps and halogen incandescent
lamps.
[0009] Of particular concern is an electric lamp having an outer
bulb and having an inner vessel, in particular a discharge vessel,
arranged therein, the inner vessel being elongate and having two
ends, the ends acting as seals, and the outer bulb being an open
tube made from glass and having two ends, at least one end being
sealed by an essentially planar sheet-metal part made from
resilient sheet metal, the sheet-metal part being fixed on the
associated seal. The inner vessel can in this case either be made
from glass, usually quartz glass or hard glass, or from
ceramic.
[0010] The sheet-metal part is preferably of annular design, the
outer diameter of the ring approximately corresponding to the outer
diameter of the open tube.
[0011] In order to hold the sheet-metal part on the tube, lugs,
which are bent back through approximately 90.degree. and bear on
the inside against the tube in a clamping manner, are preferably
distributed over the circumference of the outer diameter of the
sheet-metal part. Another way of holding the sheet-metal part on
the tube is a circumferential bent-back cover rim, which is fixed
to the tube, for example, by means of an adhesive compound.
[0012] The outer bulb is centralized in a simple manner when the
seal has a circular cross section in the form of a cylinder.
[0013] In particular, the sheet-metal part has a central opening
which is matched to the cross section of the seal. The seal is
usually in the form of a fuse seal having a circular-cylindrical
cross section. The seal may, however, also be a pinch seal, whose
cross section is essentially rectangular.
[0014] A particularly simple way of stopping and holding the
sheet-metal part securely on the seal is achieved by the seal being
cylindrical with a given diameter and opening out over one edge
into an extension part which is in the form of an open tube having
a relatively large diameter, the diameter of the central opening of
the sheet-metal part being matched to that of the seal.
[0015] The outer bulb is fixed in a clamping manner by the lugs of
the sheet-metal part not being straight but being bent out in the
manner of a roof.
[0016] The sheet-metal part is matched to the seal by a zone, which
surrounds the central opening, of the sheet-metal part being bent
out slightly from the plane of the sheet-metal part.
[0017] This is preferably achieved by the zone being divided into a
plurality of tabs by means of radial slots, said tabs being capable
of individually being bent up slightly.
[0018] The two seals are preferably designed such that the tube can
be open on both sides and can be sealed at both ends by identical
sheet-metal parts. However, it is not impossible for one end of the
tube to be fixed to the seal in a conventional manner as in the
prior art.
[0019] In the case in which a specific atmosphere is desired in the
outer bulb, the outer bulb can be kept air-tight or vacuum-tight by
a suitable sealing means, such as a sealing ring, being introduced
in the contact region between the sheet-metal part and the end of
the open tube.
[0020] In one preferred embodiment, the inner vessel is sealed at
two mutually opposing ends with identical seals, the outer bulb
being fixed to identical seals of the inner vessel at both ends by
means of a sheet-metal part.
[0021] At least some of the sheet-metal part can, in particular, be
coated by an oxidic layer, in particular titanium oxide, in order
to prevent photo ionization being produced by means of UV
radiation. Furthermore, the oxidic layer improves thermal
insulation.
[0022] A method for producing a lamp having an outer bulb follows
the following steps, namely that an open tube is pushed centrally
over an inner vessel, and then a sheet-metal part is placed onto
the open end of the tube, the lugs being bent back through
approximately 90.degree., and the central opening being selected to
be slightly smaller than the cross section of the associated seal,
with the result that, when it is placed on the seal, the central
opening is enlarged to the diameter of the seal by the individual
tabs of the surrounding zone being bent out slightly from the plane
of the sheet-metal part.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The invention will be explained in more detail below with
reference to a plurality of exemplary embodiments. In the
drawings:
[0024] FIG. 1 shows a perspective side view of a metal halide
lamp;
[0025] FIG. 2 shows various views of one exemplary embodiment of a
sheet-metal part;
[0026] FIGS. 3 to 5 show various views of further exemplary
embodiments of a sheet-metal part; and
[0027] FIG. 6 shows a side view of a further exemplary embodiment
of a halogen incandescent lamp.
BEST MODE FOR CARRYING OUT THE INVENTION
[0028] FIG. 1 shows the perspective view of a metal halide lamp 1
sealed at two ends. The discharge vessel 2 which is in the form of
a barrel body and is made from quartz glass (or else
Al.sub.2O.sub.3 ceramic) encloses two electrodes 3 (only one is
visible) in addition to a metal halide filling. A coating 11 is
applied at the level of the electrodes 3. The bulb ends are sealed
off by means of fuse seals 4, in which foils 5 are embedded. These
foils 5 are connected to outer power supply lines 6. The outer
power supply line 6 is guided in a tubular sleeve 7 and ends at a
base part (not illustrated). The central part of the discharge
vessel is surrounded by an outer bulb 12.
[0029] The outer bulb 12 comprises a tube 13 which is open at both
ends, is made, for example, from hard glass and has a considerably
larger diameter than the discharge vessel 2. A sheet-metal part 14
in the form of a disk-shaped circular ring is fixed to each of the
ends of said tube 13. The outer diameter of the sheet-metal part 14
approximately corresponds to the diameter of the open tube 13.
Bent-back lugs 15, which guide the tube 13, are distributed over
the circumference.
[0030] The sheet-metal part 14 also has a central opening 19, as
shown in FIG. 2, which is matched to the cross section of the
associated seal 4.
[0031] In order to reliably achieve this aim, a zone 20, which is
bent out slightly from the plane of the sheet-metal part, adjoins
the central opening. For this purpose, the zone 20 is divided into
five tabs 21, which are separated from one another by radially
extending slots 22.
[0032] In the still uninstalled state, these tabs 21 are initially
almost in the same plane as the rest of the sheet-metal part, but,
in contrast, are bent back through approximately 5.degree.. If the
sheet-metal part 14 is pushed onto the sleeve 7, the tabs open out
and in the process increase the size of the central opening, in
which case they surround it closely. The diameter of the seal 4 is
slightly smaller than that of the sleeve 7, with the result that
the tabs are anchored on the edge 23 there between if they slide
over the sleeve 7 finally onto the seal 4.
[0033] In the still uninstalled state, the lugs 15 are likewise
initially in the plane of the sheet-metal part 14, since initially
they are stamped out, cf. FIG. 2a. The stamped sheet-metal part is
only then preprocessed by the lugs being bent back through
approximately 90.degree. and the base of the zone being perforated,
if appropriate. Only then is the sheet-metal part pushed onto the
seal. See in this regard the schematic sectional illustration shown
in FIG. 2b and the perspective illustration shown in FIG. 2c, in
each case in the bent-back state.
[0034] FIG. 3 shows one exemplary embodiment of a sheet-metal part
25 having a continuously circumferential rim 26 made from spring
steel. This rim 26 can be fixed to the open end of the tube 13 by
means of adhesive, as a result of which an air-tight seal is made
possible there. However, it is generally sufficient if the two
sheet-metal parts merely fix the outer bulb between them, in which
case they themselves are stopped at the edge of the seal. Another
possibility for the outer bulb being kept air-tight is for a
sealing ring 40 to be introduced in the contact region between the
sheet-metal part and the end of the open tube 13, cf. FIG. 3b.
[0035] FIG. 4 shows a sheet-metal part 27 having a rectangular
opening 28. This sheet-metal part 27 is especially suitable for
discharge vessels having a pinch seal as the seal.
[0036] FIG. 5 shows an exemplary embodiment of a sheet-metal part
30 having lugs 31, which are bent back out slightly in the form of
a roof. This embodiment also fixes the outer bulb 13 in a clamping
manner such that rattling noises are reliably suppressed.
[0037] Finally, FIG. 6 shows a halogen incandescent lamp 35, in the
case of which one end 36 of the outer bulb is fixed in a manner
known per se to the seal 4 of the inner vessel by means of being
integrally formed on a bead 37. The other open end 38 of the outer
bulb is fixed to a sheet-metal part 14, as described.
[0038] In this case, the central part 12 of the outer bulb has a
larger diameter than the ends 36 and 38. The open tube 7 behind the
fuse seal 4 has a markedly larger diameter than said fuse seal 4,
as a result of which the sheet-metal part 14 is stopped reliably at
the edge there between. Although such an edge is not absolutely
necessary if the spring force of the sheet-metal part is selected
to be sufficiently high, it does considerably improve the stopping
effect.
* * * * *