Electric lamp and discharge devices: systems – Combined load device or load device temperature modifying... – Discharge device load
Reexamination Certificate
2001-03-23
2004-05-11
Wong, Don (Department: 2821)
Electric lamp and discharge devices: systems
Combined load device or load device temperature modifying...
Discharge device load
C315S291000, C439S615000
Reexamination Certificate
active
06734633
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a bulb-form lamp and a manufacturing method of a lamp case, and more particular, to a bulb-form lamp, which is constructed in a manner that a threaded portion of a lamp cap for making an electrical connection with a lighting circuit of the bulb-form lamp is formed out of a conductive resin.
For example, as a conventional bulb-form lamp, there is a compact self-ballasted fluorescent lamp. The compact self-ballasted fluorescent lamp is constructed in the following manner. More specifically, as shown in
FIG. 13
, an envelope
91
comprises a glass glove
11
and a lamp case
25
. Further, an arc tube
10
, a printed circuit board
13
on which a lighting circuit
14
, and two lead wires
15
a
and
15
b
connected to the lighting circuit
14
so as to supply a power are received in the envelope
91
.
A lamp cap
5
is screwed onto one end portion of the lamp case
25
so that the lamp case
25
is prevented from loosening by caulking or the like. The lamp cap
5
comprises a metal shell
5
c
forming a threaded portion
53
, and an eyelet
5
a
fixed by pouring an eyelet glass
5
b
functioning as an insulator into the distal end portion of the metal shell
5
c
. The metal shell
5
c
and the eyelet
5
a
are integrated with each other. These metal shell
5
c
and eyelet
5
a
constitute an electrode for supplying a power to the lighting circuit
14
.
The eyelet
5
a
consists mainly of Ni (nickel) plating brass. One lead wire
15
a
is let from a central hole
52
of the eyelet
5
a
to the outside, and then, is connected to the outer surface of the eyelet
5
a
by soldering. In this case, although is not shown, there is the case where the lead wire
15
a
and the eyelet
5
a
are connected by plasma arc welding using no solder in the light of environmental protection.
On the other hand, the metal shell
5
c
consists of metal such as Ni plating brass, aluminum or the like. The other lead wire
15
b
is led from the rear end portion of the metal shell
5
c
to the outside, and then, is connected to the outer surface of the metal shell
5
c
by soldering. In this case, although is not shown, there is the case where the lead wire
15
b
and the metal shell
5
c
are connected by resistance welding or TIG welding in the light of environmental protection.
The following is a description on a manufacturing method of the conventional bulb-form lamp as described above.
First, an arc tube
10
is assembled to a holder
12
, and thereafter, is fixed by a silicon bonding agent or the like. A printed circuit board
13
is fixed with respect to the holder
12
fixing the arc tube
10
on the side opposite to the mounted arc tube
10
. Thereafter, the lamp case
25
is fitted into the holder
12
mounting the arc tube
10
and the printed circuit board
13
. A silicon bonding agent or the like is filled into a circular-arc gap formed at a portion where the lamp case
25
is fitted into the holder
12
, and subsequently, the glove
11
is inserted and fixed into the circular-arc gap filled with the bonding agent. Then, the silicon bonding agent filled into the circular-arc or the like is dried and hardened in a high temperature furnace, and thereby, the lamp case
25
and the glove
11
is fully assembled with respect to the holder
12
.
Next, the lamp cap
5
is screwed into the distal end portion of the lamp case
25
, and subsequently, the lamp case
25
is fixed by caulking. In the case of assembling the lamp cap
5
to the lamp case
25
, the lead wire
15
a
is led out of the central hole
52
of the eyelet
5
a
while the lead wire
15
b
is led out of the proximal portion of the metal shell
5
c.
Thereafter, the led-out portion of the lead wire
15
b
is connected to the outside of the metal shell
5
c
by soldering or resistance welding and TIG welding. Likewise, the lead wire
15
a
led out of the central hole
52
of the eyelet
5
a
is connected to the outside of the eyelet
5
a
by soldering or plasma arc welding.
In the manner as described above, the bulb-form lamp shown in
FIG. 13
is completed.
By the way, in the above conventional bulb-form lamp, the lamp case
25
is independently molded out of a resin, and the lamp cap
5
is manufactured by an exclusive maker in a manner that the eyelet
5
a
and the metal shell
5
c
are fixed by the eyelet glass
5
b
. For this reason, in order to assemble the lamp cap
5
into the lamp case
25
, the following various processes must be carried out; more specifically, when manufacturing the bulb-form lamp, the lamp cap
5
is inserted and screwed into the lamp case
25
, and thereafter, is fixed by caulking. As a result, many working processes (man-hour) are required.
Further, when screwing the lamp cap
5
, in the case where the threaded portion
53
of the metal shell
5
c
is strongly griped by an automatic machine, there is a possibility that the threaded portion
53
is deformed, and the eyelet glass
5
b
breaks or cracks.
Furthermore, in the case where caulking with respect to the lamp cap
5
is insufficient, the lamp cap
5
looses and comes off; conversely, in the case where caulking is too strong, there is a possibility that the lamp case
25
is broken. For this reason, it is difficult to control a caulking strength.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above problems. It is, therefore, an object of the present invention to provide a bulb-form case, which can simplify an assembly of the bulb-form case so as to reduce an assembly cost, and has a high quality, and to provide a manufacturing method of a lamp case.
In order to solve the above problem, the present invention provides the following technical means. More specifically, according to one aspect, the present invention provides a bulb-form lamp comprising: an arc tube; a lighting circuit for lighting the arc tube; a lamp case receiving the lighting circuit; and a lamp cap mounted outside the lamp case and functioning as an electrode of the lighting circuit, a threaded portion of the lamp cap, that is, a shell being made of a conductive resin.
According to the present invention, the conductive resin shell functions as an electrode for supplying a power to the lighting circuit like the conventional metal shell. Moreover, in general, the conductive resin has a hardness lower than metal; therefore, it is possible to improve a combined strength in which the conductive resin shell is engaged with a male-threaded portion of socket when using the bulb-form lamp.
In the technical means of the present invention, the conductive resin shell is a composite part, which is molded integrally with the lamp case. By doing so, there is no need of carrying out processes for inserting the lamp cap into the lamp case, screwing, and caulking when assembling the bulb-form lamp like the conventional case. Therefore, it is possible to prevent a deformation of threaded portion by the assembling work, and no problem arises such that caulking is insufficient with respect to the lamp cap; for this reason, the lamp cap looses and comes off.
In the technical means of the present invention, the conductive resin shell and an eyelet constituting a distal portion of the lamp cap are composite parts, which are molded integrally with the lamp case. The resin portion of the lamp case is extended to an eyelet glass insulator of the conventional lamp cap, and thereby, there is no need of using the eyelet glass. Therefore, no problem arises such that the eyelet glass cracks like the conventional case.
In the technical means of the present invention, a part of the conductive resin shell is provided with a terminal connective portion projecting into the lamp case, and the terminal connective portion is connected with the lighting circuit so that the conductive resin shell and the lighting circuit are electrically connected. The lighting circuit is assembled to the lamp case so as to be connected with the terminal connective portion of the conductive resin shell, and thereby, the conductive resin shell and the ligh
Arikawa Tomotaka
Hirokawa Haruyuki
Ishitsuka Shinichiro
Kawase Masato
Matsuba Tetsuo
Fitch Even Tabin & Flannery
Matsushita Electronics Corporation
Vu Jimmy T
Wong Don
LandOfFree
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