Electricity: electrical systems and devices – Electrostatic capacitors – Variable
Reexamination Certificate
2001-03-12
2002-10-08
Reichard, Dean A. (Department: 2831)
Electricity: electrical systems and devices
Electrostatic capacitors
Variable
C361S280000, C361S278000
Reexamination Certificate
active
06462930
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum variable capacitor device that is used for various applications such as an oscillator of a high power transmitter, a high frequency power source of a semiconductor manufacturing device, a tank circuit of an inductive heating device.
FIG.
3
and
FIG. 4
show, respectively, a longitudinal cross section and a partly enlarged section of a vacuum variable capacitor, according to Japanese Patent Unexamined Publication (refereed to as “Kokai Koho” in Japanese) No. 11(1999)273998 which is an equivalent for Japanese Patent Application No. 10(1998)0074755.
There is provided an insulated cylinder
1
made of an insulating material such as ceramic and the like. As is seen in
FIG. 3
, the insulated cylinder
1
has first and second ends, which are respectively, joined with a first cylinder
2
a
and a second cylinder
2
b,
to thereby form a cylindrical shape. The first and second ends of the insulated cylinder
1
are made of copper, and are blocked by means of, respectively, an immovable end plate
3
and a movable end plate
4
, to thereby form a vacuum container
5
. Inside the immovable end plate
3
, there are provided a plurality of first cylindrical electrode plates F than range from F
1
to F
n
having different diameters. The first cylindrical electrode plates F
1
to F
n
stand on the inside of the immovable end plate
3
, and are concentrically disposed at regular radial intervals, to thereby form an immovable electrode
6
.
There is provided a conductor
7
for mounting a movable electrode
8
. The conductor
7
is so disposed in the vacuum container
5
as to oppose the immovable end plate
3
. On a first side of the conductor
7
facing the immovable end plate
3
, there are provided a plurality of second cylindrical electrode plates M that range from M
1
to M
n
having different diameters. The second cylindrical electrode plates M
1
to M
n
stand on the first side of the conductor
7
, and are concentrically disposed at regular radial intervals, to thereby form the movable electrode
8
. Each of the second cylindrical electrode plates ranging from M
2
to M
n
is put and ousted from between adjacent two of the first cylindrical electrode plates F
1
to F
n
(interdigitation), while each of the first cylindrical electrode plates ranging from F
1
to F
n−1
is put and ousted from between adjacent two of the second cylindrical electrode plates M
1
to M
n
(interdigitation). There is provided a center pin
9
standing at an internal center of the immovable end plate
3
. There is provided a movable guide
10
which is cylindrical and functions as a guide. The movable guide
10
also functions as a lead. The movable guide
10
is so disposed as to penetrate through a center of the conductor
7
. The center pin
9
is inserted into the movable guide
10
in a slidable manner.
There is provided a bellows
15
having a first end which is mounted to the movable guide
10
. The bellows
15
is cylindrical and retractable. Moreover, the bellows
15
is used for maintaining a vacuum condition and for energizing. The bellows
15
further has a second end mounted to an internal face of the movable end plate
4
. There is defined an opening
4
a
in the movable end plate
4
. The opening
4
a
is disposed on a radial inner side of the second end of the bellows
15
. There is provided a nut receptacle
11
which is cylindrical, and stands around the entire circumference of the opening
4
a
on the internal face of the movable end plate
4
. There is formed a collar
11
a
at an internal end of the nut receptacle
11
. There is provided a screw shaft
12
having a first end which is connected to the movable guide
10
. The screw shaft
12
also has a second end projecting into the nut receptacle
11
through the collar
11
a.
There is provided an adjuster nut
13
having a first end which is so supported to the collar
11
a
by way of a bearing
16
as to rotate arbitrarily. The first end of the adjuster nut
13
defines a screw shaft opening
13
a
so that the adjuster nut
13
is screwed down on the screw shaft
12
. The second end of the screw shaft
12
defines a coaxial screw opening
12
a.
With the screw opening
12
a,
the screw shaft
12
is screwed down on an adjuster screw
14
having a screw head
14
a.
Moreover, the adjuster nut
13
has a large opening
13
b
adjacent to the screw shaft opening
13
a.
The large diameter opening
13
b
is larger in diameter than the screw shaft opening
13
a.
There is defined a stage
13
c
between the screw shaft opening
13
a
and the large diameter opening
13
b.
Described below is how to assuredly maintain a maximum electrostatic capacity of the vacuum variable capacitor having the constitution as mentioned above, and to facilitate adjustment of the maximum electrostatic capacity: At first, turn the adjuster nut
13
slightly clockwise (for right handed screw) so as to shift the screw shaft
12
slightly lower than a position X (not shown) of the maximum electrostatic capacity (at the position X, a lower end of the center pin
9
abuts on an upper end of the screw shaft
12
), to thereby adjust the maximum electrostatic capacity to its predetermined value. The slight adjustment depends on the variation of the electrostatic capacity of the vacuum variable capacitors. Then, screw the adjuster screw
14
into the screw opening
12
a
to such an extent that the screw head
14
a
abuts on the stage
13
c.
Thereafter, fix the adjuster screw
14
to the screw shaft
12
by means of an adhesive and the like. Thereby, even if the adjuster nut
13
is likely to make a counterclockwise turn at the position X of the maximum electrostatic capacity, the screw head
14
a
of the adjuster screw
14
abuts on the stage
13
c.
Consequently, this can prevent the adjuster nut
13
from making the counterclockwise turn. Therefore, the screw shaft
12
cannot go up beyond the position X of the maximum electrostatic capacity. With this, the maximum electrostatic capacity can be assuredly maintained, and the adjustment of the maximum electrostatic capacity can be facilitated.
On the contrary, described below is how to arbitrarily variably adjust the electrostatic capacity of the vacuum variable capacitor having the constitution as mentioned above:
At first, turn the adjuster nut
13
so as to move the movable electrode
8
upward and downward by way of the screw shaft
12
and the movable guide
10
. With this, a total area of the movable electrode
8
opposed to the immovable electrode
6
is varied, to thereby arbitrarily variably adjust the electrostatic capacity. With the center pin
9
and the movable guide
10
provided for constituting a guide mechanism, the movable electrode
8
can be moved stably, and a withstand voltage as well as the electrostatic capacity can show stabilized characteristics.
In the above mentioned related art, the movable guide
10
is integrated with a movable lead. Contrary to this, however, the movable guide
10
can be separated from the movable lead. Moreover, the movable guide
10
is to be electrically insulated from the center pin
9
. The first end of the bellows
15
can be mounted to the conductor
7
, instead of the movable guide
10
.
When using the above vacuum variable capacitor for matching impedance of the semiconductor thin film manufacturing device, an operator needs to use a constitution shown in
FIG. 5
for the following reason: Since a load changes continuously, it is necessary to carry out the impedance matching of the vacuum variable capacitor following the load change. More specifically, as is seen in
FIG. 5
, a vacuum variable capacitor
19
is mounted horizontally on a mounting base
17
by way of a pair of mounting plates
18
, and a driving portion
21
is also mounted horizontally on the mounting base
17
by way of a mounting plate
20
. A rotational shaft
22
of the driving portion
21
is coupled with the adjuster nut
13
by way of a coupling member
23
. Driving the driving portion
21
allows the adjuster nu
Fukai Toshimasa
Hayashi Naoki
Nemoto Tomofumi
Foley & Lardner
Kabushiki Kaisha Meidensha
Reichard Dean A.
Thomas Eric W.
LandOfFree
Vacuum variable capacitor device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vacuum variable capacitor device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vacuum variable capacitor device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2935310