Metal working – Method of mechanical manufacture – Electrical device making
Reexamination Certificate
1999-11-19
2001-12-25
Hall, Carl E. (Department: 3729)
Metal working
Method of mechanical manufacture
Electrical device making
C029S609100
Reexamination Certificate
active
06332262
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a loudspeaker suspension device and a fabricating method thereof, and more particularly to a loudspeaker suspension device and a fabricating method thereof, capable of providing an improved connection state of signal input ends of voice coil connection conductors.
2. Related Background Art
In order to reduce the number of wiring steps of a loudspeaker, various types of dampers with conductors
2
(hereinafter called “conductive damper ID) have been proposed heretofore, in which the conductors
2
are provided along corrugations
11
c
of a suspension
1
generally called spiders or dampers. However, these conductive dampers
1
D are not satisfactory in terms of practical use. As described in EP 0 369 434 A2 and EP 0 479 317 A2, the inventors have proposed practically usable conductive dampers (hereinafter called “sewn conductive dampers
1
D
s
) which are already under mass production. This sewn conductive damper uses as the conductors
2
conductive wires (hereinafter called “flat knitted tinsel wires
2
h
) made of a desired number of flat knitted conductive wires each formed by winding a copper foil around fibers. This flat knitted tinsel wire is sewn on a base cloth B made of woven cloth and constituting a suspension
1
. The base cloth B with the sewn flat knitted tinsel wires is thermally molded to attache the conductors
2
along corrugations
11
c.
An edge (hereinafter called a “conductive edge
1
E”) utilizing the technology proposed by the inventors has also been proposed.
A loudspeaker suspension
1
such as a sewn conductive damper
1
D
s
and a conductive edge
1
E, having conductor
2
along corrugations
11
c
or roll
11
r
of the suspension
1
, is called a “conductive suspension
1
”.
The structure of the conductive suspension
1
having the conductors
2
mounted along the corrugations
11
c
or roll
11
r
of a conventional general loudspeaker suspension will be described by taking as an example the conductive damper
1
D and the conductive edge
1
E. In manufacturing the conductive damper
1
D, for example, in manufacturing the sewn conductive damper
1
D
s
proposed by the present inventors, phenol resin raw liquid generally sold in markets is diluted with methanol to obtain phenol resin solution having a desired specific gravity. Woven cloth made of cotton or chemical fibers is dipped in this solution to impregnate or coat it with the phenol resin. After the methanol solvent is evaporated to remove resin tucking, the woven cloth is cut to have a predetermined width. In this manner, the base cloth B used for damper molding is prepared.
Two flat knitted tinsel wires
2
h
as the conductors
2
are sewn to the base cloth B with sewing threads
3
called cornex, in parallel along the center line and at a predetermined space relative to the center line, as shown in FIG.
8
. After the flat knitted tinsel wires
2
h
are sewn, the base cloth B is thermally pressed, similar to general dampers, to integrally mold the corrugations
11
c
concentrically to the center line of the base cloth B, as shown in FIG.
9
. Thereafter, unnecessary portions indicated by broken lines in
FIG. 10
are trimmed through punching press. In this manner the sewn conductive damper
1
D with the flat knitted tinsel wires
2
h
being mounted along the corrugations
11
c
can be obtained as shown in
FIGS. 11A and 11B
.
The manufacture of the conductive edge
1
E, for example, the sewn conductive edge
1
E
s
(refer to
FIG. 3
of an embodiment of the invention) the present inventors have proposed in practical use, is basically the same as the manufacture of the sewn conductive damper
1
D
s
. Specifically, a predetermined woven cloth is impregnated with phenol resin or the like having a predetermined concentration and coated with a predetermined damping material such as synthetic rubber to prepare the edge material. This edge material is cut to have a predetermined width to prepare the base cloth B to be used for edge molding. Two flat knitted tinsel wires
2
h
similar to the above-described wires
2
h
as the conductors
2
are sewn to the base cloth B with sewing threads
3
called cornex, in parallel along the center line and at a predetermined space relative to the center line.
After the flat knitted tinsel wires
2
h
are sewn, the base cloth B is thermally pressed, similar to general edge molding, to integrally mold the roll
11
r
relative to the center line of the base cloth B. Thereafter, unnecessary portions are trimmed. Generally, if the unnecessary portions are cut through punching press, the sewn conductive edge
1
E
s
with the flat knitted tinsel wires
2
h
being mounted along the roll
11
r
can be obtained.
The structure of the conductive suspension
1
of a conventional loudspeaker is fabricated in the above method. It is therefore obvious that the conductor
2
made of the flat knitted tinsel wire
2
h
is disposed on the front surface of the suspension base cloth B made of a woven cloth impregnated or coated with resin. Therefore, exposed is only one side of the conductor
2
, i.e., the flat knitted tinsel wire
2
h
, and the other side is hidden in contact with the suspension base cloth B.
Next, a means for electrically interconnecting the conductor
2
and an input terminal lug
4
will be described by taking as an example the sewn conductive damper
1
D
s
. As shown in
FIGS. 11A and 11B
, tongue-shaped projections (hereinafter called tongue portions
13
a
and
13
b
) are provided extending outward from an adhesion portion
12
at the circumferential area of the sewn conductive damper where the conductors
2
or sewn flat knitted tinsel wires
2
h
reach. The ends
2
ha
and
2
hb
of the flat knitted tinsel wires
2
h
extend on the tongue portions
13
a
and
13
b.
In order to perform electrical connection under the conditions that the sewn conductive damper
1
D
s
is mounted on a speaker frame F, as shown in
FIG. 12
, the tongue portions
13
a
and
13
b
are disposed on input terminals mounted on the speaker frame F. The surfaces of the ends
2
ha
and
2
hb
of the flat knitted tinsel wires
2
h
at the tongue portions
13
a
and
13
b
are made in contact with, or pressed against, partial areas of terminal lugs
4
a
and
4
b
, and the contact areas or pressed areas of the lugs
4
a
and
4
b
are soldered. Therefore, partial areas of the terminal lugs
4
a
and
4
b
are made always in contact with the front surfaces of the conductors
2
(flat knitted tinsel wire ends
2
ha
and
2
hb
).
Another approach is to separate the ends of conductors
2
or flat knitted tinsel wire ends of the sewn conductive damper
1
D
s
from the damper base cloth B to expose both the front and back surfaces of the flat knitted tinsel wire ends
2
ha
and
2
hb
and jump the ends
2
ha
and
2
hb
directly to the input terminal lugs
4
. This connection structure of the sewn conductive damper
1
D
s
has been proposed by the present inventors, as described in Japanese Patent Laid-Open Gazette No. HEI 2-134100 and Utility Model Laid-Open Gazette No. HEI 2-13398.
In this electrical connection process, as shown in
FIGS. 13A and 13B
, the tongue portions
13
a
and
13
b
at the damper circumferential area are required to be separated from the flat knitted tinsel wire ends
2
ha
and
2
hb
on the tongue portions
13
a
and
13
b
, by loosening the sewing thread
3
in the range from the outermost ends of the tongue portions
13
a
and
13
b
to the outermost circumference of the adhesive area
12
. It is also necessary to peel off the flat knitted tinsel wire ends
2
ha
and
2
hb
from the tongue portions
13
a
and
13
b
to cut the loosened threads
3
. Thereafter, both the front and back surfaces of the flat knitted tinsel wire ends
2
ha
and
2
hb
are exposed to separate them from the damper base cloth B (tongue portions
13
a
and
13
b
). This process, however, has the problems of (1) high cost and (2) unstable product quality.
The reason of the high cost (1) is as follows. The
Hall Carl E.
Kabushiki Kaisha Kenwood
Nixon & Peabody LLP
Robinson Eric J.
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