Information
-
Patent Grant
-
6515412
-
Patent Number
6,515,412
-
Date Filed
Tuesday, October 24, 200023 years ago
-
Date Issued
Tuesday, February 4, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Kim; Robert H.
- Barber; Therese
Agents
-
CPC
-
US Classifications
Field of Search
US
- 313 31801
- 313 31805
- 313 31806
- 313 31812
- 313 484
- 313 485
- 313 491
- 439 226
- 439 243
- 439 336
-
International Classifications
-
Abstract
A fluorescent lamp includes a light-emitting tube having a pair of electrodes therein, a base in which the light-emitting tube is fixed, and a base contact pin terminal supported by the base with one end thereof projecting from the base. The base contact pin terminal is electrically connected to an electrode lead wire drawn from the light-emitting tube. The base is provided with a first power-conducting member including the base contact pin terminal having a lead plate, a connecting terminal having a lead plate and connected to the electrode lead wire, and a thermal protection element connected to the lead plate of the base contact pin terminal and the lead plate of the connecting terminal. The manufacturing processes of a fluorescent lamp provided with a thermal fuse are simplified and can be performed easily.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fluorescent lamp.
2. Description of the Related Art
Conventionally, during the last period of the life of a fluorescent lamp, when all electron emitting substances filled into an electrode filament coil dissipate, a cathode drop voltage rises and power consumption in an electrode increases. Thus, the temperature in the vicinity of an electrode sealing portion on the end of a light-emitting tube is excessively increased, and heat generation may occur. As a method for preventing such a rise in temperature or excessive heat generation from occurring, the following has been known: A thermal fuse or the like is provided in the vicinity of the end of the light-emitting tube. The excessive heat generated in the end of the light-emitting tube melts and cuts off this thermal fuse, so that a lighting circuit is interrupted (see JP 2-192650A and JP 4-61740A).
In recent years, a compact one-base-type fluorescent lamp with a small tube diameter has been developed and commercially expanded as an energy-saving light source to be substituted for light bulbs or the like. When such a fluorescent lamp is lit by a high-frequency electronic circuit, a preheating current may continue to flow through the electrode filament coil depending on the electronic circuit system, even if the lamp cannot light up because of the dissipation of all the electron emitting substances in the last period of lamp life.
In this case, the glass temperature of the electrode sealing portion rises excessively because an arc discharge or the like is generated between the electrode lead wires holding the electrode filament coil, thereby causing a breakdown. Thus, the preheating current flows in the glass between the electrode lead wires to increase the temperature of the electrode sealing portion excessively.
For one-base-type fluorescent lamps, a rise in temperature of the electrode sealing portion is especially remarkable, and thus a base made of a resin material may be deformed by heat. In order to prevent such a rise in temperature, the high-frequency electronic circuit is generally provided with a so-called protection circuit for detecting the dissipation of all the electron emitting substances in the electrode and stopping the electronic circuit operation. However, even if such a protection circuit is provided, the failure of the protection circuit, though it rarely occurs, may cause the above-mentioned base deformation or the like. As a method for preventing such a rise in temperature of the electrode sealing portion that leads to the base deformation or the like, the following has been known: A thermal protection element, such as a thermal fuse or the like is provided in the base so as to be connected in series with an outer electrode lead wire (see JP 10-188906A and JP 11-111231A).
FIG. 33
shows an example of a configuration of a one-base-type fluorescent lamp according to the conventional techniques. In a light-emitting tube
137
(with an outer diameter of about 17 mm) having a pair of electrodes therein, four straight glass tubes
138
,
139
,
140
, and
141
are joined to form a discharge path therein. A base
142
is provided on the end of the tube of the light-emitting tube
137
. Base contact pin terminals
145
,
151
,
152
, and
153
are provided on the base
142
and connected to electrode lead wires
144
,
148
,
149
, and
150
drawn from the light-emitting tube
137
, respectively. In the base
142
, a thermal protection element
143
that acts as a thermal fuse is connected to the electrode lead wire
144
drawn from the light-emitting tube
137
and the base contact pin terminal
145
by caulking.
In addition to the four straight tubes type described above, two, six, and eight straight tubes types conventionally have been known as the one-base-type fluorescent lamps. Among these types, e.g., in the one-base-type fluorescent lamp of four straight tubes type provided with the thermal protection element (hereinafter referred to as a thermal fuse)
143
, as shown in
FIG. 33
, the base
142
generally includes a light-emitting tube holding member
146
and a base body
147
that mainly are made of a resin material, as shown in FIG.
34
.
In the manufacturing processes for this type of fluorescent lamp, first, the ends of the four tubes of the light-emitting tube
137
are inserted into circular holes of the light-emitting tube holding member
146
, and then fixed with an adhesive of a silicone resin or the like. Then, one end of the thermal fuse
143
and one end of the electrode lead wire
144
are connected. Then, the light-emitting tube holding member
146
and the base body
147
are fixed. Finally, the remaining three electrode lead wires
148
,
149
, and
150
and the other end of the thermal fuse
143
are connected to the base contact pin terminals
151
,
152
,
153
, and
145
attached to the base body
147
by soldering or caulking. Also, in the two, six, and eight straight tubes types (with an outer diameter of the light-emitting tube of about 12 mm or about 17 mm), the base includes two parts that are basically the same as in the above four straight tubes type. In addition, the base assembly process is basically the same.
On the other hand, as an example of the kind of high wattage lamp of the two straight tubes type (with an outer diameter of the light-emitting tube of about 20 mm, and the electric power of 28 W. 36 W. 55 W, or 96 W), a lamp with the structure shown in
FIGS. 35
,
36
, and
37
is provided.
FIG. 35
is a sectional front view of a base portion, and
FIGS. 36 and 37
are plan views thereof. In this lamp, a base
154
is provided with a base body
155
, two covers
156
,
157
shown in
FIG. 37
, and two thermal fuses
158
,
159
shown in FIG.
36
.
FIG. 36
is a plan view of a base not including the covers
156
,
157
.
In the manufacturing processes for this type of fluorescent lamp, the thermal fuses
158
,
159
are accommodated in the predetermined positions in the base body
155
. Then, one side lead wire of each of the thermal fuses
158
,
159
is inserted into respective base contact pin terminals
160
,
161
. At the same time, electrode lead wires
166
,
167
drawn from a light-emitting tube
164
are inserted into base contact pin terminals
163
,
162
, respectively. Then, the light-emitting tube
164
is fixed in the base body
155
with a silicon adhesive or the like. The electrode lead wires
166
,
167
, and the one side lead wire of each of the thermal fuses
158
,
159
that have been inserted into the base contact pin terminals
160
,
161
,
162
, and
163
, then are connected to the base contact pin terminals
160
,
161
,
162
, and
163
, respectively, by caulking. Furthermore, electrode lead wires
165
,
168
and the other side lead wire of each of the thermal fuses
158
,
159
are connected by caulking terminals
169
made of metal, and then the connected portions are inserted into the base body
155
to which the two covers
156
,
157
are attached.
In a conventional fluorescent lamp without the thermal fuse, e.g., when a base is attached, electrode lead wires are arranged straight so as to be led to base contact pin terminals. Thus, when the end of a light-emitting tube is inserted into the base, the electrode lead wires spontaneously are led to and inserted into the corresponding base contact pin terminals, respectively. Therefore, for the conventional fluorescent lamp without the thermal fuse, the processes from the manufacture of a fluorescent lamp to base assembly generally are performed by a series of automatic manufacturing equipment or the like, so that mass production easily is achieved, and thus the manufacturing cost of lamps can be lowered.
However, for a conventional fluorescent lamp with the thermal fuse described above, in its manufacturing processes, it is difficult to connect the lead wires of the thermal fuse to an electrode lead wire of the light-emitting tube and a base contact pin terminal by automation, and thus these connections have to be established by manual operation. As a result, the manufacturing cost of lamps increases.
In a time of saving energy, to supply safe and popularly priced one-base-type fluorescent lamps to the market as an energy-saving light source to be substituted for light bulbs, reduction of the manufacturing cost of lamps provided with the thermal fuse is a task to be achieved.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind, it is an object of the present invention to provide a fluorescent lamp that easily can achieve the mass production of lamps by a series of automatic manufacturing equipment or the like while simplifying the manufacturing processes of a fluorescent lamp provided with a thermal fuse and facilitating the operation thereof, and that can reduce the manufacturing cost significantly. It is another object of the present invention to provide a fluorescent lamp with excellent safety that ensures that the thermal fuse provided therein is melted and cut off as the temperature rises excessively in the last period of lamp life.
A fluorescent lamp of the present invention includes a light-emitting tube having a pair of electrodes therein, a base for fixing the light-emitting tube, and a base contact pin terminal supported by the base with one end thereof projecting from the base. The base contact pin terminal and an electrode lead wire drawn from the light-emitting tube are electrically connected. The base is provided with a first power-conducting member including the base contact pin terminal having a lead plate, a connecting terminal having a lead plate and connected to the electrode lead wire, and a thermal protection element connected to the lead plate of the base contact pin terminal and the lead plate of the connecting terminal.
This allows the manufacturing processes of a fluorescent lamp to be reduced and simplified in comparison with the conventional techniques. In addition, the mass production of lamps by a series of automatic manufacturing equipment or the like easily can be achieved, and thus the manufacturing cost required for producing fluorescent lamps can be reduced significantly. Furthermore, as the temperature rises excessively in the last period of lamp life, the thermal fuse provided in a lamp can be melted and cut off reliably, so that fluorescent lamps with excellent safety can be obtained.
These and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG.1
is a partial sectional front view showing a one-base-type fluorescent lamp of a first embodiment of the present invention.
FIG. 2
is an enlarged sectional front view showing a substantial part of the fluorescent lamp of FIG.
1
.
FIG. 3
is a plan view showing a base of the fluorescent lamp of FIG.
1
.
FIG. 4
is a bottom view of the base of FIG.
3
.
FIG. 5
is a perspective view showing a power-conducting member of the base of FIG.
3
.
FIG. 6
is a plan view showing a base of a fluorescent lamp of a second embodiment of the present invention.
FIG. 7
is a bottom view of the base of FIG.
6
.
FIG. 8
is a partial sectional front view showing a substantial part of a fluorescent lamp of a third embodiment of the present invention.
FIG. 9
is a plan view showing a base of the fluorescent lamp of FIG.
8
.
FIG. 10
is a bottom view of the base of FIG.
9
.
FIG. 11
is a partial sectional perspective view showing a fluorescent lamp of a fourth embodiment of the present invention.
FIG. 12
is an enlarged front view of a substantial part of the fluorescent lamp of FIG.
11
.
FIG. 13A
is a plan view for describing a base structure of the fluorescent lamp of FIG.
11
.
FIG. 13B
is a perspective view showing a power-conducting member of the base of FIG.
13
A.
FIG. 14
is a partial sectional front view showing the base of FIG.
13
A.
FIG. 15
is an enlarged front view showing a substantial part of a fluorescent lamp of a fifth embodiment of the present invention.
FIG. 16A
is a plan view for describing a base structure of the fluorescent lamp of FIG.
15
.
FIG. 16B
is a perspective view showing a power-conducting member of the base of FIG.
16
A.
FIG. 17
is a partial sectional front view of the base of FIG.
16
A.
FIG. 18
is a plan view showing a base of a fluorescent lamp of a sixth embodiment of the present invention.
FIG. 19
is a sectional front view showing a substantial part of a fluorescent lamp of a seventh embodiment of the present invention.
FIG. 20
is a bottom view showing a base body of the fluorescent lamp of FIG.
19
.
FIG. 21
is a bottom view of a base including the base body of
FIG. 20
provided with a cover.
FIG. 22A
is a perspective view showing a first power-conducting member of the base body of FIG.
20
.
FIG. 22B
is a perspective view showing a second power-conducting member of the base body of FIG.
20
.
FIG. 23
is an enlarged sectional front view showing a substantial part of the base body of FIG.
20
.
FIG. 24
is a front view showing a cover of the base body of FIG.
20
.
FIG. 25
is a front view showing a metal part used for power-conducting members of the base body of FIG.
20
.
FIG. 26
is a sectional front view showing a substantial part of a fluorescent lamp of an eighth embodiment of the present invention.
FIG. 27
is a bottom view showing a base body of the fluorescent lamp of FIG.
26
.
FIG. 28
is a bottom view of a base including the base body of
FIG. 27
provided with a cover.
FIG. 29
is a sectional front view showing a substantial part of a fluorescent lamp of a ninth embodiment of the present invention.
FIG. 30
is a plan view showing a base of the fluorescent lamp of FIG.
29
.
FIG. 31
is an enlarged sectional front view showing a substantial part of the base of FIG.
30
.
FIG. 32
is a view for describing a circuit configuration of a lighting circuit for lighting a fluorescent lamp of the present invention.
FIG. 33
is a partial sectional perspective view showing a conventional fluorescent lamp.
FIG. 34
is an exploded perspective view showing a substantial part of the fluorescent lamp of FIG.
33
.
FIG. 35
is a sectional front view showing a base portion of the fluorescent lamp of FIG.
33
.
FIG. 36
is a plan view showing a base of the fluorescent lamp of
FIG. 33
without a cover.
FIG. 37
is a plan view showing a base of the fluorescent lamp of
FIG. 33
with covers attached.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
FIG. 1
shows a one-base-type fluorescent lamp of the kind of high wattage lamp of the two straight tubes type, according to a first embodiment of the present invention. In a light-emitting tube
1
, two straight glass tubes
2
,
3
are joined with a so-called bridge junction
4
. Thus, a discharge path is formed inside the light-emitting tube
1
between electrode filament coils
5
and
6
provided on the ends of both tubes. Electrode stems
7
,
8
made of glass are fixed by sealing to the ends of both tubes of the light-emitting tube
1
, respectively. Four electrode lead wires
9
and
10
,
11
and
12
holding the electrode filament coils
5
,
6
, respectively, are fixed by sealing to the electrode stems
7
,
8
. The four electrode lead wires
9
,
10
,
11
, and
12
are drawn out of the light-emitting tube
1
. The light-emitting tube
1
is filled with an inert gas such as argon or the like and mercury, and phosphors are applied to the inner surface thereof. As a completed lamp, a base
13
is fixed on both ends of the light-emitting tube
1
with an adhesive (not shown) of a silicone resin or the like. Numerals
18
,
20
denote the base contact pin terminals.
FIGS. 2
,
3
, and
4
show the structure of the base
13
in detail. The base
13
includes a base body
14
and covers
15
,
16
. The base body
14
is made of a resin material, such as polyethylene terephthalate (hereinafter referred to as PET). As shown in
FIG. 3
, first power-conducting members
17
are fixed to the base body
14
.
As shown in
FIG. 5
, the first power-conducting members
17
include at least three types of metal parts, i.e., four base contact pin terminals
18
,
19
,
20
, and
21
, thermal protection elements (hereinafter referred to as a thermal fuse)
22
,
23
, and pin-shaped connecting terminals
24
,
25
. The base contact pin terminals
18
,
19
,
20
, and
21
are drawn out of the base
13
and connected to the lead wires of an outer electronic lighting circuit or the like. The thermal fuses
22
,
23
are made of metal having a low melting point of 168° C. The electrode lead wires
9
,
12
drawn from the light-emitting tube
1
are connected to the connecting terminals
24
,
25
.
FIG. 5
shows one of the first power-conducting members
17
; the other has the same structure.
In the first power-conducting members
17
, the base contact pin terminal
18
or
21
and the connecting terminal
24
or
25
are connected via the thermal fuse
22
or
23
. In order to establish the connections between the base contact pin terminals
18
,
21
and the connecting terminals
24
,
25
more easily, lead plates
18
a
,
21
a
are attached to the base contact pin terminals
18
,
21
and lead plates
24
a
,
25
a
are attached to the connecting terminals
24
,
25
, respectively, as an integral part. The base contact pin terminals
18
,
21
and the lead plates
18
a
,
21
a
, and the connecting terminals
24
,
25
and the lead plates
24
a
,
25
a
, respectively, are made of a metal material of brass or nickel or the like as an integrally formed metal part. Both ends of the thermal fuses
22
,
23
are connected to one end of each of the lead plates
18
a
,
24
a
,
21
a
and
25
a
, respectively. Since the thermal fuses
22
,
23
are metal with a low melting point, i.e. a so-called solder, the electrical connections between the thermal fuses
22
,
23
and the lead plates
18
a
,
24
a
,
21
a
, and
25
a
are easily established by soldering.
Furthermore, in this embodiment, when the base
13
is formed, part of the first power-conducting members
17
is embedded in the base
13
so that the base
13
is integral with the first power-conducting members
17
. The portion of the first power-conducting members
17
embedded in the base
13
is chosen so as not to cause interference with the connection to an outer electronic lighting circuit, the thermal fuses
22
,
23
, or the electrode lead wires
9
,
12
or the like.
An example of the manufacturing processes of the base
13
is as follows: First, at the same time as resin molding of the base body
14
, the base contact pin terminals
18
,
19
,
20
and
21
and the connecting terminals
24
,
25
are installed to form an integral part of the base body
14
. Then, the thermal fuses
22
,
23
are soldered to one end of each of the lead plates
18
a
,
21
a
,
24
a
, and
25
a.
In the manufacturing process of another example, first, the base body
14
is formed by resin molding. Then, the base contact pin terminals
18
,
19
,
20
, and
21
and the connecting terminals
24
,
25
that constitute the first power-conducting members
17
are forced into the predetermined positions of the base body
14
to be attached thereto, and thus the base body
14
is completed. Then, the thermal fuses
22
,
23
are soldered to one end of each of the lead plates
18
a
,
21
a
,
24
a
, and
25
a
, respectively. The thermal fuses
22
,
23
may be fixed previously inside the base
13
by soldering. Alternatively, the thermal fuses
22
,
23
may be soldered after the fluorescent lamp manufacturing process (a) or (b), which will be described later.
The covers
15
,
16
are made of a resin material of PET or the like and cover the thermal fuses
22
,
23
or the connecting terminals
24
,
25
or the like inside the base body
14
so that they cannot be seen from the outside, as shown in FIG.
2
. This can provide an appearance that does not reduce the commercial value of the product because the parts of the lead plates or the like or wiring points inside the base are covered and cannot be seen. Two covers
15
,
16
are used in this embodiment as shown in
FIGS. 1
to
4
. However, as will be described later, the covers
15
and
16
can be formed into one part.
As described above, in this embodiment, at least part of the base contact pin terminal and the connecting terminal, or at least part of each lead wire provided on the base contact pin terminal and the connecting terminal is embedded in the base. According to this configuration, since the first power-conducting members
17
including the base contact pin terminals
18
,
19
,
20
, and
21
, the thermal fuses
22
,
23
, and the connecting terminals
24
,
25
are wired beforehand and placed in the base
13
, a fluorescent lamp with the thermal fuse can be obtained by the same processes as in a fluorescent lamp without the thermal fuse. Therefore, the manufacturing processes of a fluorescent lamp can be reduced and simplified in comparison with those of the conventional fluorescent lamp with a thermal fuse. In addition, it is possible easily to realize the mass production of lamps by automation and to reduce the manufacturing cost required for producing fluorescent lamps significantly.
The manufacturing processes of a fluorescent lamp of this embodiment can be performed as follows:
(a) The end of the light-emitting tube
1
is installed in the base body
14
, and then fixed by injecting an adhesive (not shown) of a silicone resin or the like into the gap between the end of the tube of the light-emitting tube
1
and the base body
14
. In this installation, two electrode lead wires
9
,
12
are inserted into the connecting terminals
24
,
25
, respectively, and the other two electrode lead wires
10
,
11
are inserted into the base contact pin terminals
19
,
20
, respectively.
(b) Then, by caulking each of the terminals
19
,
20
,
24
and
25
, the electrode lead wires
9
,
10
,
11
, and
12
are connected to each of the terminals
19
,
20
,
24
, and
25
.
(c) Thereafter, each of the covers
15
,
16
is attached to the base body
14
.
The thermal fuses
22
,
23
can be inserted from the opposite side of the light-emitting tube
1
with respect to the base body
14
and connected to each of the lead plates
18
a
,
24
a
,
21
a
, and
25
a.
Second Embodiment
Abase
26
of a fluorescent lamp of a second embodiment of the present invention will be described with reference to
FIGS. 6 and 7
.
The base
26
has a partly modified structure of the base
13
of the first embodiment. Therefore, the identical elements to those of the first embodiment are denoted by the same reference numerals, and repetition of the description will be omitted. In addition to first power-conducting members
17
, second power-conducting members
34
are incorporated in a base body
27
. The second power-conducting members
34
include connecting terminals
28
,
29
to which electrode lead wires
10
,
11
are connected. The connecting terminal
28
or
29
and the base contact pin terminal
30
or
31
are integrally formed via lead plate
32
or
33
.
Other base structure and assembly process are basically the same as in the first embodiment.
Third Embodiment
A base
35
of a fluorescent lamp of a third embodiment of the present invention will be described with reference to
FIGS. 8
to
10
.
In the base
35
, four base contact pin terminals
36
,
37
,
38
, and
39
are arranged linearly. With the linear arrangement of the base contact pin terminals
36
,
37
,
38
, and
39
, the shapes or the positions of installation or the like of connecting terminals
40
,
41
, the base contact pin terminals
37
,
38
, lead plates
37
a
,
38
a
, covers
15
,
16
, or the like are modified appropriately. The electrode lead wires
9
,
12
and
10
,
11
are inserted into and connected to the connecting terminals
40
,
41
and the base contact pin terminals
36
,
39
, respectively.
Fourth Embodiment
FIG. 11
shows a one-base-type fluorescent lamp of the six straight tubes type of a fourth embodiment of the present invention. In a light-emitting tube
47
of this embodiment, six straight glass tubes
48
,
49
,
50
,
51
,
52
, and
53
are joined with bridge junctions. Thus, a discharge path is formed inside the light-emitting tube
47
between electrode filament coils
54
and
55
provided on the both ends of the tube. Four electrode lead wires
56
,
57
,
58
, and
59
are drawn out of the light-emitting tube
47
. Like each of the above embodiments, the light-emitting tube
47
is fixed in a base
60
with an adhesive (not shown) of a silicone resin or the like.
FIGS. 12
to
14
show the base
60
in detail. The base
60
includes a light-emitting tube holding member
61
and a base body
62
. The light-emitting tube holding member
61
is made of a resin material of PET or the like and holds the light-emitting tube
47
fixed with an adhesive or the like. The base body
62
is made of a resin material of PET or the like, to which first power-conducting members
63
are fixed as an integral part.
As shown in
FIG. 13A
, the first power-conducting members
63
include, like each of the above embodiments, four base contact pin terminals
64
,
65
,
66
, and
67
, thermal fuses
68
,
69
, and pin-shaped connecting terminals
70
,
71
to which the electrode lead wires
56
,
59
are connected. The connecting terminals
70
,
71
are provided so as to extend to the light-emitting tube
47
side.
In the first power-conducting members
63
, as shown in
FIG. 13B
, the base contact pin terminals
64
(
67
) and the connecting terminals
70
(
71
) are connected via the thermal fuses
68
(
69
). In order easily to establish the connections between the base contact pin terminals
64
,
67
and the connecting terminals
70
,
71
, lead plates
64
a
,
67
a
,
70
a
, and
71
a
are attached to the base contact pin terminals
64
,
67
and the connecting terminals
70
,
71
, respectively, as an integral part. The electrical connections between the thermal fuse
68
and the lead plates
64
a
,
70
a
, and between the thermal fuse
69
and the lead plates
71
a
,
67
a
are established easily by soldering.
As an example of the manufacturing processes of forming the base body
62
, the following processes, which are the same as in the first embodiment, can be used. First, at the same time as resin molding of the base body
62
, the base contact pin terminals
64
,
65
,
66
, and
67
and the connecting terminals
70
,
71
are installed to form an integral part of the base body
62
. Then, the thermal fuses
68
,
69
are soldered to one end of each of the lead plates
64
a
,
70
a
,
67
a
, and
71
a.
As the manufacturing processes of another example, the following processes can be used. First, the base body
62
is formed by resin molding. Then, the base contact pin terminals
64
,
65
,
66
, and
67
and the connecting terminals
70
,
71
that constitute the first power-conducting members
63
are forced into the predetermined positions of the base body
62
to be attached thereto, and thus the base body
62
is completed. Then, the thermal fuses
68
,
69
are soldered to one end of each of the lead plates
64
a
,
70
a
,
67
a
, and
71
a
, respectively. The thermal fuses
68
,
69
may be fixed previously inside the base
60
by soldering. Alternatively, the thermal fuses
68
,
69
may be soldered after the fluorescent lamp manufacturing process (a) or (b), which will be described below.
The manufacturing processes of a fluorescent lamp of this embodiment may include the following:
(a) First, the end of the light-emitting tube
47
is installed in the light-emitting tube holding member
61
, and then fixed with an adhesive of a silicone resin or the like.
(b) Then, the electrode lead wires
56
,
59
are inserted into the connecting terminals
70
,
71
, respectively. At the same time, the electrode lead wires
57
,
58
are inserted into the base contact pin terminals
65
,
66
, respectively. By caulking each of the terminals
70
,
71
,
65
, and
66
, the electrode lead wires
56
,
57
,
58
, and
59
are connected to each of the terminals
70
,
71
,
65
, and
66
.
(c) Finally, the light-emitting tube holding member
61
is attached to the base body
62
.
Fifth Embodiment
A base
72
of a fluorescent lamp of a fifth embodiment of the present invention will be described with reference to
FIGS. 15
to
17
.
The base
72
includes a light-emitting tube holding member
61
, a base body
62
, and a cover
73
made of a resin material of PET or the like. The base
72
has a slightly modified structure of the base
60
of the fourth embodiment. In other words, as shown in
FIGS. 16A and 17
, it differs from the fourth embodiment in the shapes and the positions of installation of first power-conducting members
81
, i.e., base contact pin terminals
74
,
75
,
76
, and
77
, connecting terminals
78
,
79
, lead plates
74
a
,
78
a
,
77
a
, and
79
a
, and thermal fuses
80
. The connecting terminals
77
,
78
are provided so as to extend downward, as shown in
FIGS. 16B and 17
.
The manufacturing processes of a fluorescent lamp of this embodiment can be performed as follows: First, while the electrode lead wires
56
,
59
of the light-emitting tube
47
held by the light-emitting tube holding member
61
are inserted into the connecting terminals
78
,
79
and the electrode lead wires
57
,
58
are inserted into the base contact pin terminals
75
,
76
, respectively, the base body
62
is attached to the light-emitting tube holding member
61
. Thereafter, the four electrode lead wires
56
,
57
,
58
, and
59
are connected to each of the corresponding terminals by caulking. Then, the cover
73
is attached to the base body
62
to cover the connecting terminals
78
,
79
or the like so that they cannot be seen.
Sixth Embodiment
A base
82
of a fluorescent lamp of a sixth embodiment of the present invention will be described with reference to FIG.
18
.
The base
82
has a slightly modified structure of the base body
62
of the fifth embodiment. In other words, connecting terminals
83
,
84
are provided, and the connecting terminals
83
,
84
and the base contact pin terminals
75
,
76
are connected via lead plates
85
,
86
to form second power-conducting members
34
.
Seventh Embodiment
A base
87
of a fluorescent lamp of a seventh embodiment of the present invention will be described with reference to
FIGS. 19
to
25
.
The base
87
includes a base body
88
and a cover
89
. First power-conducting members
90
and second power-conducting members
91
are fixed to the base
87
. As shown in
FIG. 22A
, the first power-conducting members
90
include three major metal parts, i.e., base contact pin terminals
92
(
95
), thermal fuses
22
(
23
), and slit-forming connecting terminals
96
(
99
). As shown in
FIG. 22B
, the second power-conducting members
91
include two major metal parts, i.e., base contact pin terminals
93
(
94
), and slit-forming connecting terminals
97
(
98
). The base contact pin terminals
92
,
93
,
94
, and
95
are drawn out of the base
87
and connected to the lead wires of an outer electronic lighting circuit or the like. The electrode lead wires
9
,
10
,
11
, and
12
drawn from the light-emitting tube
1
are connected to the connecting terminals
96
,
97
,
98
, and
99
.
In the first power-conducting members
90
, the base contact pin terminals
92
,
95
and the connecting terminals
96
,
99
are connected via the thermal fuses
22
,
23
. The base contact pin terminals
92
,
95
are attached to one end of each of lead plates
92
a
,
95
a
, respectively, by caulking. The connecting terminals
96
,
99
are integrally formed at one end of each of the lead plates
96
a
,
99
a
, respectively. Both ends of the thermal fuse
22
are connected to the connecting terminals
92
b and
96
b
, respectively. The connecting terminals
92
b
,
96
b are provided on the other end of each of the lead plates
92
a
,
96
a
and have a slit or a groove or the like. Similarly, both ends of the thermal fuse
23
also are connected to the connecting terminals on the other end of each of the lead plates
95
a
,
99
a
. The electrical connections between the thermal fuse
22
and the lead plates
92
a
,
96
a
, and between the thermal fuse
23
and the lead plates
95
a
,
99
a
easily are established in such a manner that the ends of the thermal fuse
22
or
23
are inserted into the connecting terminals
92
b
and
96
b
, or the like of the corresponding lead plates to be caulked and soldered.
On the other hand, in the second power-conducting members
91
, the base contact pin terminal
93
or
94
and the connecting terminal
97
or
98
are connected by lead plate
97
a
or
98
a
. The connecting terminals
97
,
98
are formed integrally at one end of each of the lead plates
97
a
,
98
a
, respectively. The base contact pin terminals
93
,
94
are attached to the other end of each of the lead plates
97
a
,
98
a
by caulking.
Accommodating holes
100
,
101
in which the thermal fuses
22
,
23
are accommodated are formed in the base body
88
. The lead plates
92
a
,
95
a
and the lead plates
96
a
,
99
a
(along with the base contact pin terminals
92
,
95
and the connecting terminals
96
,
99
) are embedded in the base body
88
so that the ends of the lead plates to which the thermal fuses
22
,
23
are connected are positioned inside the accommodating holes
100
,
101
. The thermal fuses
22
,
23
are accommodated in the accommodating holes
100
,
101
and connected to the end of each of the lead plates
92
a
,
95
a
and
96
a
,
99
a
, respectively. In the plan view of
FIG. 20
, the portion of each lead plate embedded into the base body is shown in broken lines.
As shown in
FIG. 24
, a cover
89
is provided to cover the thermal fuses
22
,
23
or the connecting terminals
96
,
97
,
98
, and
99
or the like inside the base body
88
so that they cannot be seen from the outside, and thus the commercial value of the appearance is not reduced. The cover
89
is engaged with the base body
88
by engagement pieces (not shown), and easily can be attached thereto. Furthermore, recesses
102
,
103
,
104
, and
105
for receiving the slit-forming end portions of the connecting terminals
96
,
97
,
98
, and
99
are formed on the inner surface of the cover
89
. This can prevent the lead wires
9
,
10
,
11
, and
12
from slipping off the connecting terminals
96
,
97
,
98
, and
99
during the transportation of lamps or the like (see FIG.
23
). The cover
89
can be attached to the base body simply by fitting therein, which makes it easy to achieve a lamp assembly process by automatic manufacturing equipment.
As shown in
FIG. 23
, the accommodating holes
100
(
101
) are substantially sealed with accommodating covers
100
a
(
101
a
) made of the same resin material as the base body
88
, using ultrasonic welding or the like. This structure is used for preventing oxidation of the surfaces of the thermal fuses
22
,
23
that are exposed to an atmosphere of relatively high temperature (about 120° C.) during the lamp life, so that the thermal fuses
22
,
23
can be melted and cut off when the temperature rises excessively in the last period of lamp life, and thus function as a protection element. The results of studies by the present inventors indicated that when the thermal fuses
22
,
23
were placed merely in an open atmosphere of the base
13
, the surfaces of the thermal fuses were oxidized to form a metal oxide layer of PbO or SnO or the like during the lamp life, and the thermal fuses might not function because when the temperature rose excessively, the oxide layer on the surface was not melted while the metal itself inside the thermal fuses was melted. Furthermore, it was also confirmed that filling the accommodating holes
100
,
101
with reducing substances (not shown), such as pine resin or the like was effective in preventing the oxidation of the thermal fuses
22
,
23
more reliably.
The use of the slit-forming terminals as the connecting terminals
96
,
97
,
98
, and
99
facilitates the respective connections between the electrode lead wires
9
,
10
,
11
, and
12
and the connecting terminals
96
,
97
,
98
, and
99
by automatic manufacturing equipment. As described above, the ends of the connecting terminals
92
b
,
96
b
or the like, by which the thermal fuses
22
,
23
and the lead plates
92
a
,
96
a
,
99
a
, and
95
a
are connected, have a slit or the like, so that establishing these connections by automatic manufacturing equipment is easy. In this case, of the elements that constitute the second power-conducting members
91
and the first power-conducting members
90
, the metal parts, i.e., the connecting terminals
96
(
99
) and
97
(
98
), the lead plates
92
a
(
95
a
),
96
a
(
99
a
), and
97
a
(
98
a
), and the connecting terminals
92
b
,
96
b
(or the like), can be manufactured by punching and forming a metal plate, as shown in FIG.
25
. Thus, at the same time as the resin molding of the base body
88
, which will be described later, these metal parts are fixed easily as an integral part of the base body
88
. In that case, the base body
88
is completed by cutting the unnecessary portions of the embedded metal parts.
FIG. 25
shows one of the metal parts; the other has the same structure.
An example of the processes of manufacturing the base
87
is as follows: First, at the same time as resin molding of the base body
88
, the base contact pin terminals
92
,
93
,
94
, and
95
and the connecting terminals
96
,
97
,
98
, and
99
, the lead plates
92
a
,
96
a
,
99
a
, and
95
a
and the connecting terminals
92
b
,
96
b
or the like on the end of each of the lead plates, which constitute the first power-conducting members
90
and the second power-conducting members
91
, are fixed to form an integral part of the base body
88
. Then, the thermal fuses
22
,
23
are caulked and soldered to the connecting terminals
92
b
,
96
b
or the like on the end of each of the lead plates
92
a
,
96
a
,
95
a
, and
99
a.
As other manufacturing processes of the base
87
, the following processes can be used. First, at the same time as resin molding of the base body
88
, the connecting terminals
96
,
97
,
98
, and
99
, the lead plates
92
a
,
96
a
,
95
a
, and
99
a
, and the connecting terminals
92
b
,
96
b
or the like on the end of each of the lead plates are fixed to form an integral part of the base body
88
. Then, the base contact pin terminals
92
,
93
,
94
, and
95
are forced into the predetermined positions of the base body
88
to be attached thereto, and connected to one end of each of the lead plates
92
a
,
93
a
,
94
a
, and
95
a
, respectively, by caulking. Then, the thermal fuses
22
,
23
are caulked and soldered to the connecting terminals
92
b
,
96
b
or the like on the end of each of the lead plates
92
a
,
96
a
,
95
a
, and
99
a
, respectively. However, the thermal fuses
22
,
23
can be fixed previously inside the base body
88
by caulking and soldering. Alternatively, the thermal fuses
22
,
23
can be caulked and soldered after the fluorescent lamp manufacturing process (a), which will be described below.
An example of the manufacturing processes of a fluorescent lamp of this embodiment includes the following processes:
(a) First, the end of the light-emitting tube
1
is installed in the base body
88
, and then fixed with an adhesive (not shown) of a silicone resin or the like. In this installation, the four electrode lead wires
9
,
10
,
11
, and
12
are connected to the slit-forming connecting terminals
96
,
97
,
98
and
99
, respectively.
(b) Then, the cover
89
is attached to the base body
88
.
As described above, according to this embodiment, the first power-conducting members
90
and the second power-conducting members
91
that include the base contact pin terminals
92
,
93
,
94
, and
95
, the thermal fuses
22
,
23
, and the slit-forming connecting terminals
96
,
97
,
98
, and
99
, or the like are wired inside the base body
88
beforehand. The use of such a base allows a fluorescent lamp with the thermal fuse to be produced by the same processes as in the conventional fluorescent lamp without the thermal fuse. Therefore, in the manufacturing processes of a fluorescent lamp, the process performed by manual operation can be reduced and the process conventionally performed by manual operation can be facilitated by automation in comparison with the manufacturing processes of the conventional fluorescent lamp with the thermal fuse. In addition, it is possible easily to achieve the mass production of lamps by automation and to reduce significantly the manufacturing cost required for producing fluorescent lamps. Furthermore, since the thermal fuses
22
,
23
are provided so as to be substantially sealed in the closed accommodating holes
100
,
101
, the oxidation of the thermal fuses
22
,
23
during lamp life is prevented. Thus, the thermal fuses
22
,
23
are melted and cut off reliably when the temperature rises excessively in the last period of lamp life, so that fluorescent lamps with excellent safety can be obtained.
Eighth Embodiment
A base
106
of a fluorescent lamp of an eighth embodiment of the present invention will be described with reference to
FIGS. 26
to
28
.
The base
106
includes a base body
107
and a cover
107
a
. In the base body
107
, four base contact pin terminals
110
,
111
,
112
, and
113
that constitute first power-conducting members
108
and second power-conducting members
109
are arranged linearly. With the linear arrangement of the base contact pin terminals
110
,
111
,
112
, and
113
, the shapes or the positions of installation or the like of the base contact pin terminals
110
,
111
,
112
, and
113
, thermal fuses
114
,
115
, the slit-forming connecting terminals
116
,
117
,
118
, and
119
, lead plates
110
a
,
113
a
,
116
a
,
117
a
,
118
a
, and
119
a
, and the cover
107
a
or the like are properly adjusted. The electrode lead wires
9
,
10
,
11
, and
12
are connected to the connecting terminals
116
,
117
,
118
, and
119
. The thermal fuses
114
,
115
are provided in the closed accommodating holes
120
,
121
, respectively. As shown in
FIG. 26
, the accommodating hole
120
is substantially sealed with an accommodating cover
122
(similarly, the accommodating hole
121
is also substantially sealed). Furthermore, the thermal fuses
114
,
115
are caulked and soldered to the connecting terminals provided on the end of each of the lead plates
110
a
,
116
a
,
113
a
, and
119
a
in the same manner as in the seventh embodiment.
Other base structures and the processes of formation and assembly are basically the same as those of the seventh embodiment.
Ninth Embodiment
A one-base-type fluorescent lamp of the six straight tubes type of a ninth embodiment will be described with reference to
FIGS. 29
to
31
. The basic structure is the same as that of the fourth embodiment.
As shown in
FIG. 30
, a base body
135
includes first power-conducting members
123
and second power-conducting members
124
. The first power-conducting members
123
and the second power-conducting members
124
include, like each of the above embodiments, at least four base contact pin terminals
125
,
126
,
127
, and
128
, thermal fuses
129
,
130
, and the slit-forming connecting terminals
131
,
132
,
133
, and
134
to which the electrode lead wires are connected.
In the first power-conducting members
123
, the base contact pin terminals
125
,
128
and the connecting terminals
131
,
134
are connected via the thermal fuses
129
,
130
, respectively. In order easily to establish the connections between the base contact pin terminals
125
,
128
and the connecting terminals
131
,
134
, the base contact pin terminals
125
,
128
and the connecting terminals
131
,
134
are provided with lead plates
125
a
,
128
a
and
131
a
,
134
a
, respectively, like each of the above embodiments. As shown in
FIG. 31
, the thermal fuse
129
is caulked and soldered to connecting terminals
125
b
,
131
b
on the end of each of the lead plates
125
a
,
131
a
, having a slit or a groove or the like (similarly, the thermal fuse
130
also is caulked and soldered to the end of each of the lead plates
128
a
,
134
a
).
On the other hand, in the second power-conducting members
124
, the base contact pin terminals
126
,
127
and the connecting terminals
132
,
133
are connected by lead plates
132
a
,
133
a
. The connecting terminals
132
,
133
and the lead plates
132
a
,
133
a
are formed as an integral part, respectively. The base contact pin terminals
126
,
127
are attached to one end of each of the lead plates
132
a
,
133
a
by caulking.
Being connected in the manner described above, the thermal fuses
129
,
130
of the first power-conducting members
123
are accommodated in accommodating holes
100
,
101
provided in the base body
135
. Furthermore, the accommodating holes
100
,
101
are substantially sealed with accommodating covers
136
made of the same resin material as the base body
135
by ultrasonic welding.
Like each of the above embodiments, in forming the base body
135
, part of the first power-conducting members
123
and the second power-conducting members
124
, i.e., the portion in the area that does not cause interference with the connection to an outer electronic lighting circuit or the electrode lead wires or the like, is embedded in the base, so that the first power-conducting members
123
and the second power-conducting members
124
are formed to be integral with the base.
In each of the above embodiments, the number of thermal fuses to be used is preferably at least two. However, it is not necessarily two; one, three, or four may be used. The reason that the use of at least two thermal fuses is preferable is as follows. A one-base-type fluorescent lamp is generally lit by an electronic lighting circuit system shown in FIG.
32
. In
FIG. 32
, among four electrode lead wires of a lamp
42
, two are connected to a high-frequency electronic circuit
43
and the remaining two are connected to a capacitor
44
. Therefore, in the last period of lamp life, it is preferred to interrupt application of a voltage from the high-frequency electronic circuit
43
to the lamp
42
. This requires that at least one thermal fuse is inserted between the lamp
42
and the high-frequency electronic circuit
43
. On the other hand, if only one thermal fuse is used, the thermal fuse may be inserted between the capacitor
44
and the lamp
42
, depending on the polarity of the socket attachment of a lamp base. Thus, when a lamp has two thermal fuses
45
,
46
as shown in
FIG. 32
, application of a voltage from the high-frequency electronic circuit
43
always can be interrupted in the last period of lamp life, regardless of the polarity of the socket insertion of a lamp base.
In each of the above embodiments, one-base-type fluorescent lamps of the two and six straight tubes types have been described. However, the present invention can also be applied to other one-base-type fluorescent lamps of the two, four, and eight straight tubes types.
The result of life tests of the one-base-type fluorescent lamp of each of the above embodiments and studies of the condition in the last period of lamp life confirmed that the thermal fuse provided in the lamp was melted and cut off reliably when the temperature rose excessively in the last period of lamp life. Therefore, it is clear that the fluorescent lamp of each of the embodiments can provide excellent safety.
As described above, by including the configuration shown in each of the above embodiments, the manufacturing processes of a fluorescent lamp can be simpler and easier than those of the conventional lamps. In addition, the mass production of lamps by a series of automatic manufacturing equipment easily can be achieved. Thus, the manufacturing cost required for producing fluorescent lamps can be significantly reduced. Furthermore, a fluorescent lamp with excellent safety can be obtained that ensures that the thermal fuse provided in the lamp is melted and cut off as the temperature rises excessively in the last period of lamp life.
The invention may be embodied in other forms without departing from the spirit or essential characteristics thereof. The embodiments disclosed in this application are to be considered in all respects as illustrative and not limiting. The scope of the invention is indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.
Claims
- 1. A fluorescent lamp comprising:a light-emitting tube having a pair of electrodes therein; a base for fixing the light-emitting tube; and a base contact pin terminal supported by the base with one end thereof projecting from the base, the base contact pin terminal being electrically connected to an electrode lead wire drawn from the light-emitting tube, wherein the base is provided with a first power-conducting member including the base contact pin terminal having a lead plate, a connecting terminal having a lead plate and connected to the electrode lead wire, and a thermal protection element connected to an end of the lead plate of the base contact pin terminal and an end of the lead plate of the connecting terminal.
- 2. The fluorescent lamp according to claim 1, wherein the base is provided with, in addition to the first power-conducting member, a second power-conducting member including the base contact pin terminal, a connecting terminal connected to the electrode lead wire, and a lead plate connecting the base contact pin terminal and the connecting terminal.
- 3. The fluorescent lamp according to claim 1, wherein the base is provided with a cover for covering the thermal protection element and the lead plates of the base contact pin terminal and the connecting terminal.
- 4. The fluorescent lamp according to claim 1, wherein at least part of the base contact pin terminal and the connecting terminal, or at least part of each of the lead plates provided on the base contact pin terminal and the connecting terminal is embedded in the base.
- 5. The fluorescent lamp according to claim 4, wherein the base has a accommodating hole in which the thermal protection element is accommodated, and the base contact pin terminal and the connecting terminal are embedded in the base so that an end of each of the lead plates of the base contact pin terminal and the connecting terminal, to which the thermal protection element is connected, is positioned in the accommodating hole.
- 6. The fluorescent lamp according to claim 5, wherein the accommodating hole is covered with an accommodating cover.
- 7. The fluorescent lamp according to claim 5, wherein the accommodating hole in which the thermal protection element is accommodated is filled with a reducing substance.
- 8. The fluorescent lamp according to claim 1, wherein a connected portion between the electrode lead wire and the connecting terminal is a slit-forming terminal.
- 9. The fluorescent lamp according to claim 2, wherein the second power-conducting member includes a structure in which the lead plate to be attached to the base contact pin terminal and the lead plate to be attached to the connecting terminal are composed of an integral member made of a metal plate.
- 10. The fluorescent lamp according to claim 3, wherein a connected portion between the electrode lead wire and the connecting terminal is a slit-forming terminal, and a recess for receiving the slit-forming connecting terminal is provided on an inner side of the cover.
- 11. The fluorescent lamp according to claim 7, wherein the reducing substance is pine resin.
Priority Claims (2)
Number |
Date |
Country |
Kind |
11-309332 |
Oct 1999 |
JP |
|
2000-171551 |
Jun 2000 |
JP |
|
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
4703227 |
Takeda et al. |
Oct 1987 |
A |
4767965 |
Yamano et al. |
Aug 1988 |
A |
5161884 |
Siminovitch |
Nov 1992 |
A |
6297585 |
Tashiro et al. |
Oct 2001 |
B1 |
Foreign Referenced Citations (6)
Number |
Date |
Country |
0 869 541 |
Oct 1998 |
EP |
0 971 389 |
Jan 2000 |
EP |
02-192650 |
Jul 1990 |
JP |
04-061740 |
Feb 1992 |
JP |
10-188906 |
Jul 1998 |
JP |
11-111231 |
Apr 1999 |
JP |
Non-Patent Literature Citations (1)
Entry |
European Search Report. |