Note: Descriptions are shown in the official language in which they were submitted.
CA 02225039 2005-05-18
77332-6
1
Reflector Lamp
Technical Field
The invention relates to electric lamps and
particularly to electric lamps with reflectors. More
particularly the invention is concerned with an internal
mounting for an electric lamp to a reflector.
Background Art
Such a reflector lamp is already known, for
example, from EF-A 572 400. There it was a matter of an
incandescent lamp whose base is partially formed by an
insert part on the end of the neck part of the reflector.
This insert part must be attached to the neck part of the
reflector by means of cement. The disadvantages of this base
are that it is difficult to produce and does not fit very
precisely. In addition, this type construction leads to an
increase of the overall length of the reflector lamp, since
space is needed to secure the insert part underneath the
bulb in the neck portion.
Another base principle for contact pins with
cylindrical thickened portions is described in German
Utility Model DE-GM 82 34 509. There the cap for a low
pressure discharge lamp is a separate part made of plastic.
It is the object of this invention to construct at
a reasonable cost a reflector lamp and to lower the
production costs.
SUMMARY OF THE INVENTION
According to one aspect the invention provides a
reflector lamp comprising: a hermetically sealed bulb
enclosing a filling and a light source, the light source
CA 02225039 2005-05-18
77332-6
la
being a high voltage or medium voltage light source in which
an operating voltage of at least 80 volts is present, a
reflector, consisting of a basic body with a reflector
contour and a neck part attached to a rear portion of the
basic body, and a base which is joined to the neck part and
which has at least two metallic contact pins with
cylindrical seals on an end farthest from the bulb, a
current feeder system which makes an electrical lead
available for use by the light source, wherein the base is
formed completely from the same material as the neck part
and as an integral part directly on the neck part of the
reflector.
According to another aspect the invention provides
a reflector lamp comprising: a hermetically sealed bulb
enclosing a filling and a light source, a reflector,
consisting of a basic body with a reflector contour and a
neck part attached to a rear portion of the basic body, and
a base which is joined to the neck part and which has at
least two metallic contact pins with cylindrical seals on an
end farthest from the bulb, a current feeder system which
makes an electrical lead available for use by the light
source, wherein the base is formed completely from the same
material as the neck part and as an integral part directly
on the neck part of the reflector, wherein the bulb is a
separate part made of hard glass or quartz glass inside the
reflector, and the bulb is pinch sealed on one end, and
whereby the pinch is supported by means of perforate disk
surrounding the pinch in the neck part of the reflector.
According to another aspect the invention provides
a reflector lamp comprising: a hermetically sealed bulb
enclosing a filling and a light source, a reflector,
consisting of a basic body with a reflector contour and a
neck part attached to a rear portion of the basic body, and
CA 02225039 2005-05-18
77332-6
lb
a base which is joined to the neck part and which has at
least two metallic contact pins with cylindrical seals on an
end farthest from the bulb, a current feeder system which
makes an electrical lead available for use by the light
source, wherein the base is formed completely from the same
material as the neck part and as an integral part directly
on the neck part of the reflector, wherein the bulb is a
separate bulb made of quartz glass hermetically sealed by a
single pinch, wherein the reflector made of glass, and
wherein the light source is a filament with two ends which
has a U, V or W shape and is held in the bulb without any
mount construction, and wherein the bulb is held in the
reflector without cement.
The special value of the invention consists in the
production of the lamp being significantly simplified and
simultaneously
CA 02225039 1997-12-18
2
the possibility being created of making the lamp more compact
and in particular guaranteeing a high degree of operating
safety for the lamp. The reflector lamp of this invention
possesses significant cost and manufacturing advantages over
the prior art.
Either a luminous element or an electrode is possible as the
means of illumination (see for example the reflector discharge
lamp in US-PS 4 935 660). The invention is especially suited
for high voltage and medium voltage lamps. Use of the
invention for low voltage lamps, however, is not ruled out.
A special advantage is the concept of the integrated cap which
makes it possible to so organize the lead wire system that
there are no contact problems due to contact resistances which
frequently occur in the low voltage range (below 80 V) because
of smaller contact surfaces for electrical connections.
Consequently corrosion caused by age causes the high contact
resistance which results in voltage drops in the supply lines.
During operation a markedly lower voltage is applied to the
means of illumination.
Specifically the reflector lamp with a cap on one side has the
following features: a hermetically sealed bulb with a filling
and a means of illumination, a reflector, consisting of a
basic body bearing a reflector contour and a neck part placed
on the basic body's back, a cap which is attached to the neck
part and incorporates two or more metal contact pins with
cylindrical thickened portions on the end away from the bulb,
and a lead wire system which makes an electric supply line
available for the means of illumination. The cap is completely
formed by the material of the neck part and is formed as an
integral part directly on the neck of the reflector.
The bulb in the reflector lamp of this invention is usually a
separate part made of hard glass or quartz glass inside the
reflector which is pinched on one or two sides. It cannot,
CA 02225039 1997-12-18
3
however, be ruled out that the bulb is formed by the reflector
itself, in which case the reflector incorporates a
hermetically sealed covering disk (sealed beam technology).
Usually a reflector lamp incorporates a reflector made of
glass, but temperature resistant plastic is also suitable.
These materials hold their shape better and have tighter
tolerances than do ceramic materials, so the cap rests better
and more exactly in the holder. In addition ceramic is more
expensive and heavier.
The invention is especially suited for high voltage and medium
voltage lamps or, in other words, for an operating voltage of
at least 80 V. Up until now the compactness of reflector lamps
suitable for this left much to be desired.
In particular the cap is formed by a plane wall with an
interior and exterior face which is located crosswise to the
reflector axis and closes off the neck piece. It incorporates
openings parallel to the axis for contact pins.
It is advantageous to construct the contact pins as contact
pin cases with interior bored holes, with the bored holes in
the case extending over at least a portion of the length of
the case or along its entire length.
The securing of the contact pin cases can occur in a simple
manner in that the cases incorporate on the bulb side an
outwardly bent edge and, approximately in the center of the
case's length, a disk-like collar between which the wall of
the cap is locked.
In order to preclude problems when inserting into the holder,
it is useful to place at least one raised bulge on the outer
face of the wall, the thickness of which bulge equates to at
least (equal is preferred) that of the collar of the case.
CA 02225039 2005-05-18
77332-6
4
An especially interesting possibility of use for
general illumination is a reflector lamp in which the lamp
is an incandescent lamp with a bulb pinched on one side
which contains a luminous body and internal lead wires, with
the lead wires being so constructed, that they possess an
inherent fusing effect.
Possible configuration possibilities for inherent
fuses are described in a variety of documents:
Especially advantageous are inherent fuses
constructed as follows: the internal lead wires connect the
ends of the luminous bodies to the sealing foils embedded in
the pinch and are embedded in the pinch over at least a part
of their length, with at least one of the lead wires
consistina of an uncoiled wire. The inherent fuse effect is
attained i_n that at least one of the two internal lead wires
is made from a wire with a diameter of I30 um at most,
preferably 80 um at most, which is embedded in the pinch
over a length of at least 2 mm, and with the distance, d,
between the lead wires and the applied voltage, V, so
interacting that, in the event of an arc between the lead
wires, the field strength effective there, V/d, is greater
than 100 V/cm, but preferably is between 200 and 400 V/cm.
Additional details can be found in German Utility Model
DE-GM 296 07 132.
A specific advantage of an uncoiled wire in
comparison. to a single-coiled wire is that, when both wires
are embedded in the pinch over an equal length, the mass of
the lead wire made from the uncoiled wire is significantly
less than the mass of the lead wire made from the single-
coiled wire. The evaporation of the wire material in the
capillary thus advances much more quickly. The arc
extinguishes sooner and the response time of the inherent
CA 02225039 2005-05-18
77332-6
safety fuse is much shorter than for other safety fuses. In
addition, the energy in the arc is considerably lower.
The concept of an "uncoiled wire" also includes a
wire that originally was single-coiled, but which was pulled
5 in its length, so that a helically coiled wire pulled in its
length results. The pitch typically is of 10 to 100 times
the wire diameter. The wire then has not completely lost its
original helical shape, but the turns are pulled so far
apart that during pinching a hose-like cavity no longer
1C arises. At equal pinched lengths of the internal lead wires,
the length of wire actually accommodated is thus markedly
longer than for a completely uncoiled piece of wire for
which the actual accommodated wire length is identical with
the pinched wire length.
The internal lead wire preferably has a diameter
of more than 15 um. Frequently the luminous body and the
internal lead wires can be constructed as a unit from a
single wire i.e., the internal lead wires are the uncoiled
luminous body ends. It is, however, also possible to use
separate internal lead wires with a different diameter as
compared to the luminous body wire.
Other possibilities for an inherent safety fuse at
high operating voltages are known, for example, from
US-PS 4 132 922 and German Utility Model DE-GM 91 02 566.
Here the lead wires consist of singly coiled sections which
are embedded in the pinch, with their core region leaving a
hose-like cavity that acts like an exhaust channel in case
an arc forms.
Another solution for the problem is recommended in
German laid-open application DE-OS 31 10 395, namely, to
incorporate an additional, so-called, thermal fuse in the
pinch region of a halogen incandescent lamp pinched on one
CA 02225039 2005-05-18
77332-6
5a
or two sides. It basically is a matter of a cavity which is
formed in the region of the pinch and through which the
internal lead wire is passed over a part of its length.
Therefore since the lead wire is not embedded in the glass,
the lead wire heats up very quickly and melts through.
CA 02225039 1997-12-18
6
Special advantages with regard to cost and production can be
achieved when, on principle, the use of cap cement is omitted.
An elegant solution consists of using a lamp in which the bulb
is pinched on one side, with the pinch being supported in the
neck area of the reflector by means of a surrounding
perforated disk made of a spring sheet steel.
With the integral cap introduced here, the wall normally is
placed on the neck piece at a right angle. The cap can,
however,
be so constructed, that the neck part transitions over a
radially circumferential bevel into the plane wall.
A highly compact reflector lamp with a cap on one side
manifests the following features:
- a separate bulb of quartz glass hermetically sealed
by a single pinch,
- a glass reflector,
- a luminous body with two ends bent in a U, V or W shape
and held in the bulb without any mount construction (wire
mount, quartz cross-piece). The latter point is usually
difficult to realize in high or medium voltage lamps.
A particularly elegant possibility of not using a wire mount
consists of fixing the luminous body in a known manner with at
least one heat resistant means of support.
A high degree of compactness is especially difficult to attain
in high voltage or medium voltage lamps, since they are
normally operated with a safety fuse. Hence the operating
voltage amounts to at least 80 V. The lead wire system
therefore advantageously manifests internal lead wires which
are so constructed that they possess an inherent safety fuse
effect.
Finally the concept in this invention allows very short
overall lengths, which up to this point seemed illusory for
CA 02225039 2005-05-18
77332-6
7
high voltage reflector lamps, namely overall lengths of equal
to or smaller than 60 mm, and preferably even about 50 mm.
The luminous body in an incandescent lamp pinched on one side
can be mounted axially or in can be bent in a U, V or W shape.
An especially preferred embodiment finds the luminous body
split into two luminous sections which are separated from each
other by a non-luminous base piece. Lamps pinched on one side
and incorporating an axial luminous body are used in
particular f or the medium voltage applications (system
voltaaes of about 110 V). Here it is advantageous to connect
only the end of the luminous body located next to the pinch
with the sealing foil via a lead wire with an inherent safety
fuse effect. The other lead wire which is led as the mount
wire to the end farthest from the pinch is a solid wire.
Preferably the luminous body is supported by means of a heat
resistant supporting means which can withstand an arc, for
example, a solid wire mount or, preferably, glass webs which
are formed from the material of the bulb.
The lamp of this invention can be produced at a favorable
cost, since few component parts are needed and production can
be easily automated.
All in all, a reflector lamp has been introduced which is
characterized by improved operating safety and previously
unattained compactness.
The reflector lamp of this invention is especially suited for
direct operation off a system voltage, by which a range from
approx. 80 V to 250 V is to be understood. Typical wattages
are 25 to 150 Watts. Because of its compactness this lamp can
be used for many applications (e. g. PAR lamps, aluminum plated
reflector lamps, cold light reflector lamps).
CA 02225039 2005-05-18
77332-6
8
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1, shows a preferred embodiment of an
incandescent reflector lamp.
FIG. 2, shows a preferred embodiment of a
discharge reflector lamp.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Figure 1 shows a compact high voltage reflector
lamp 40 for general illumination purposes with a power of
50 W which is suited for direct connection to a 240 V
system. Its total overall length amounts to only 49 mm. The
burner has a cylindrical bulb 41 of quartz glass with an
outer diameter of about 13.5 mm, an inner diameter of 11 mm
and an overall length of about 38 mm (prior art 86 mm).
One ena of the bulb 41 forms a dome 63 which
incorporates an exhaust tip 64 in the center. The other end
of the bulb is closed with a pinched seal 45. The bulb is
filled with an inert aas mixture of 80° Kr and 20% N to
which a halogen additive of .0050 CBrCIF2 is added.
A tungsten luminous body 56 bent approx. in a U-
shape extends over almost the entire interior length of the
bulb volume, with the base part 57 of the "U" which extends
crosswise to the lamp axis being located in the vicinity of
the dome 63, whereas the two legs of the "U" which form the
actual luminous filament sections 47 extend from the base
part 57 to the pinched seal 45 and thereby open slightly in
an outward direction toward the pinched seal 45. The two
luminous filament sections 47 transition at their ends into
short, about 4 to 7 mm, uncoiled wire sections 59 which
function as internal lead wires with an inherent safety fuse
effect. The internal lead wires 59 are melted into the
CA 02225039 2005-05-18
77332-6
~a
pinched seal 45 over a short length (typically 3 mm or less)
and are welded there to the molybdenum sealing foils. The
lead wires 59 extend several millimeters out of the pinched
seal (typically 3 to 5 mm) and into the volume of the bulb.
The exterior lead wires 50 which extend out of the
pinched
CA 02225039 1997-12-18
9
seal 45 are welded to the external ends of the foils 60. They
are angled off in an outward direction and threaded into the
bored holes 54 of the contact pin cases 51. The cases 51 have
cylindrical thickened portions 52 on the end.
The base part 57 of the "U" is uncoiled. It is arranged
crosswise to the lamp axis just below the exhaust tube tip 64.
Its ends are bent at about 90 degrees and extend to the
filament sections 47. The filament pattern shown with two
short, parallel legs 47 located close next to each other, is
advantageous for the lamp distribution in the reflector. The
dimensions of both filament legs are about .5 x 9.5 mm.
The luminous element is fixed at the level of the base part 57
by a single, oval glass web 42 which is made from the material
of the bulb. The base part 57 is pinched in the glass web 42.
In this manner extreme compactness of the lamp is achieved.
All in all, the bulb attains an overall length of only 38 mm,
calculated from the pinch to the exhaust tube tip. The bulb
can therefore be housed in a very compact reflector 43 of
(hard) glass with an outer diameter of 50 mm.
The reflector of borosiliacte glass consists of a basic body
43, which is shaped like a spherical cap and has an interior
contour 66, as well as the neck part 46 being placed on the
basic body's back. The contour is coated with aluminum or a
thin interference filter system. The latter is effective as a
cold light mirror. The reflector opening is closed by a
covering disk 61.
To better fix the bulb a springy, slamply arched, perforated
disk 44 made of sheet metal is used which is located at the
level of the pinch attachment 45 on the bulb. It has an
opening adapted for the pinch and two guide clips located on
the narrow sides of the pinch. The perforated disk 44 rests on
four, long bulges 67 parallel to the axis (only two are
CA 02225039 1997-12-18
visible in Figure 1) which protrude from the neck 46 of the
reflector. The attaching of the bulb occurs without any cap
cement, in that the spring effect of the perforated disk is
used (similar to the description in DE-GM 195 48 521). The
bulb is thus placed into the neck part under pressure and then
the external lead wires are crimped to the cases.
The reflector tapers toward the end of the reflector neck 46
and to an outer diameter of 20 mm. The total length of the
reflector lamp is 49 mm.
To shorten the overall length, the reflector lamp has a glass
cap 48 formed directly on the reflector neck. This consists
essentially of a plane wall 49 at the end of the reflector
neck, which functions as an integral bottom part. The external
lead wires 50 of the built-in lamp are led outward through two
openings 53 and are thereby threaded into the bored holes 54
of two metal contact pin cases 51 resting in the openings 53 .
The bored holes extend over a part of the length of the case,
with the external lead wires 50 being crimped (55) into the
case 51 (alternatively they can be soldered into a bored hole
which passes all the way through).
The contact pin cases 51 themselves are pinned into the
openings 53 in that the inner edge 70 of the case is bent
around the inner face 71 of the wall and simultaneously a
disk-like collar 72 formed on the center of the case rests on
the outer face 73 of the wall. The two contact pin cases 51
have a center separation of 10 mm.
Customary reflector lamps for high or medium voltage operation
usually incorporate in the lead wire system between the
spherical reflector cap and the cap a safety fuse which most
often inserts into a separate interim part (by means of
cement). It is advantageous not to use that concept, instead
the internal lead wire is an uncoiled wire with a wire
thickness of about 100 um, by which the internal lead wire
CA 02225039 1997-12-18
11
acts as an inherent safety fuse. The overall length is thereby
further reduced.
In an especially advantageous embodiment two flat, strip-like
bulges 58 are placed opposite each other crosswise (or
longitudinal) to the two contact pin cases 51 on the outer
edge of the outer face 73. The thickness of the bulges 58
matches exactly the thickness of the disk-like collars 72, so
that their respective end surfaces away from the bulb together
define a plane (as a type of working distance). In principle
the thickness of the bulges can be selected larger than that
of the collars; that however increases the overall length of
the lamp.
Thus any tilting of the contact pin cases 51 as in customary
holders (see, for example, Figure 4 of EP-A 572 400) can be
avoided. As is known the holders incorporate two long, slamply
circular, arched, slit-like openings (or recesses) on one of
whose ends is located an enlarged circular opening to insert
the contact pin cases 51. When inserting the cases 51 in these
enlarged openings , the strip-like bulges serve, on the one
hand, as a separator, so that the cases do not touch the floor
of the recess and therefore remain easily movable for the
following turning motion. On the other hand, the collars can
not unintentionally be inserted into the enlarged opening of
the holder where they would hang up when turned. Finally the
strip-like bulges cause a release of pressure for the
cylindrical thickened portions when the cap is turned in the
holder, thereby reducing the resistance during turning.
Figure 2 shows a reflector lamp 74 with an arc tube 76
designed as a metal halide lamp pinched on one side which is
further insulated by an outer bulb. Instead of several strip-
like bulges, one (or several) ring-like bulges 78 are located
on the outer edge of the wall 49. The transition between the
neck part 46 and the external face of the wall 49 is not at a
right angle, but instead is made by means of a radial,
CA 02225039 1997-12-18
12
circumferential bevel 75. All other characteristics of this
lamp resemble those of the incandescent lamp of the first
embodiment and have the same reference signs.
This present invention has particular advantages over
currently known reflector lamps, since not only the number of
component parts (now six parts; prior art ten parts including
the interim part) is reduced but also the assembly technology
can be simplified. The new product can therefore be produced
at a reduced cost, with less material and in less time.
In another embodiment of a reflector lamp for 110 V the
luminous element is axially mounted and only the lead wire
which leads to the end facing the pinch is melted as an
uncoiled wire section into the pinch. For low voltage
incandescent lamps the short luminous element is mounted
either axially or crosswise to the axis.
The invention makes available, in particular, a reasonably
priced reflector lamp with low power usage down to 25 W or
even less for direct electrical system connection (high
voltage, medium voltage) sucg as is of special interest for
general illumination. Preferred wattages are 250 W at the
most.
The invention is especially advantageous for low power (up to
75 W) halogen incandescent lamps pinched on one side, because
the use of a glass cap here demonstrates most dramatically the
invention's savings of money and space.
The invention is not limited only to the embodiment shown. It
is also well suited for use in halogen incandescent lamps
operating off a 110 V electrical system. It is also suited for
use in other types of incandescent lamps and discharge lamps.
