Information
-
Patent Grant
-
6334605
-
Patent Number
6,334,605
-
Date Filed
Wednesday, August 30, 200023 years ago
-
Date Issued
Tuesday, January 1, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Hail, III; Joseph J.
- Wilson; Lee
Agents
- Arent Fox Kintner Plotkin & Kahn, PLLC
-
CPC
-
US Classifications
Field of Search
US
- 254 126
- 254 122
- 254 100
- 254 101
- 254 98
- 254 DIG 1
-
International Classifications
-
Abstract
In a pantagraph-type jack, a base comprises an upper base member and a lower base member which are connected to each other relatively movably in the vertical direction, inner ends of a pair of lower arms are swingably connected to the upper base member via a pair of lower pivots arranged in the horizontal direction, lower sector gears are formed on the outer peripheries of the inner ends of the two lower arms, and a lower rack which meshes with the lower sector gears is disposed in the vertical direction and secured on the lower base member, and it is arranged such that at the same time as the two lower arms are erected the lower sector gears ascend the lower rack. Thus, the amount of lift of the load bearing platform can be increased without increasing the lengths of the lower arms, the upper arms and the threaded rod.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pantagraph-type jack and, in particular, an improved pantagraph-type jack, in which outer ends of a pair of lower arms disposed in a V-shaped manner whose inner ends are swingably connected to a base and outer ends of a pair of upper arms disposed in an inverted V-shaped manner whose inner ends are swingably connected to a load bearing platform are connected via first and second connecting shafts, and a threaded rod supported on the first connecting shaft in a rotatable but axially non-movable manner is screwed into a threaded bore provided in the second connecting shaft.
2. Description of the Prior Art
Such a pantagraph-type jack is already known as disclosed in, for example, Japanese Patent Publication No. 3-6120.
In such a pantagraph-type jack of the art, the degree of lift of the load bearing platform is increased by increasing the lengths of the lower arms, the upper arms and the threaded rod. However, when the lengths of the lower arms, the upper arms and the threaded rod are increased, the size of the jack increases and thus it is difficult to store it in a small storage space in an automobile, etc.
SUMMARY OF THE INVENTION
The present invention has been carried out in view of the above-mentioned circumstances, and it is an objective of the present invention to provide a compact pantagraph-type jack in which the degree of lift of the load bearing platform can be increased without increasing the lengths of the lower arms, the upper arms and the threaded rod.
In order to achieve the above-mentioned objective, the present invention provides firstly a pantagraph-type jack in which outer ends of a pair of lower arms disposed in a V-shaped manner whose inner ends are swingably connected to a base and outer ends of a pair of upper arms disposed in an inverted V-shaped manner whose inner ends are swingably connected to a load bearing platform are connected via first and second connecting shafts, and a threaded rod supported on the first connecting shaft in a rotatable but axially non-movable manner is screwed into a threaded bore provided in the second connecting shaft, wherein the base comprises an upper base member and a lower base member which are connected to each other relatively movably in a vertical direction, inner ends of the pair of lower arms are swingably connected to the upper base member via a pair of lower pivots arranged in a horizontal direction, lower sector gears are formed on outer peripheries of the inner ends of the two lower arms, and a lower rack which meshes with the lower sector gears is disposed in the vertical direction and secured on the lower base member.
In accordance with the above-mentioned first feature, when the threaded rod is rotated in a clockwise direction so as to erect each pair of lower arms and upper arms around the lower pivots and the upper pivots respectively in order to erect the collapsed or contracted jack, since the lower sector gears formed on the outer peripheries of the inner ends of the two lower arms rotate at the same time so as to ascend the lower racks, the upper base member having the lower pivots lifts relative to the lower base member having the lower racks. Therefore, the total amount of lift of the jack becomes the sum of the amount of lift of the load bearing platform due to the erection of the lower arms and the upper arms and the amount of lift of the upper base member relative to the lower base member, and thus the amount of lift can be increased in comparison with a jack of the prior art in which the amount of lift of the load bearing platform is determined only by the erection of the lower arms and the upper arms. Moreover, since it is unnecessary to specially increase the lengths of the lower arms, the upper arms and the threaded rod, the size of the jack is not made larger.
The present invention provides secondly a pantagraph-type jack in which the outer ends of a pair of lower arms disposed in a V-shaped manner whose inner ends are swingably connected to a base and outer ends of a pair of upper arms disposed in an inverted V-shaped manner whose inner ends are swingably connected to a load bearing platform are connected via first and second connecting shafts, and a threaded rod supported on the first connecting shaft in a rotatable but axially non-movable manner is screwed into a threaded bore provided in the second connecting shaft, wherein the load bearing platform comprises a lower load bearing platform member and an upper load bearing platform member which are connected to each other relatively movably in a vertical direction, inner ends of the pair of upper arms are swingably connected to the lower load bearing platform member via a pair of upper pivots arranged in the horizontal direction, upper sector gears are formed on the outer peripheries of the inner each of the two upper arms and an upper rack which meshes with the upper sector gears is disposed in the vertical direction and secured on the upper load bearing platform member.
In accordance with the above-mentioned second feature, when the threaded rod is rotated in the clockwise direction so as to erect each pair of lower arms and upper arms around the lower pivots and the upper pivots respectively in order to erect the collapsed jack, since the upper sector gears formed on the outer peripheries of the inner ends of the two upper arms rotate at the same time so as to push up the upper racks, the upper load bearing platform member having the racks lifts relative to the lower load bearing platform member having the upper pivots. Therefore, the total amount of lift of the jack becomes the sum of the amount of lift of the load bearing platform due to the erection of the lower arms and the upper arms and the amount of lift of the upper load bearing platform member relative to the lower load bearing platform member, and thus the amount of lift can be increased in comparison with a jack of the prior art in which the amount of lift of the load bearing platform is determined only by the erection of the lower arms and the upper arms. Moreover, since it is unnecessary to specially increase the lengths of the lower arms, the upper arms and the threaded rod, the size of the jack is not made larger.
The present invention further provides a pantagraph-type jack in which outer ends of a pair of lower arms disposed in a V-shaped manner whose inner ends are swingably connected to a base and outer ends of a pair of upper arms disposed in an inverted V-shaped manner whose inner ends are swingably connected to a load bearing platform are connected via first and second connecting shafts, and a threaded rod supported on the first connecting shaft in a rotatable but axially non-movable manner is screwed into a threaded bore provided in the second connecting shaft, wherein the base comprises an upper base member and a lower base member which are connected to each other relatively movably in a vertical direction, inner ends of the pair of lower arms are swingably connected to the upper base member via a pair of lower pivots arranged in a horizontal direction, lower sector gears are formed on outer peripheries of the inner ends of the two lower arms, and a lower rack which meshes with the lower sector gears is disposed in the vertical direction and secured on the lower base member, and the load bearing platform comprises a lower load bearing platform member and an upper load bearing platform member which are connected to each other relatively movably in a vertical direction, inner ends of the pair of upper arms are swingably connected to the lower load bearing platform member via a pair of upper pivots arranged in the horizontal direction, upper sector gears are formed on the outer peripheries of the inner ends of the two upper arms, and an upper rack which meshes with the upper sector gears is disposed in the vertical direction and secured on the upper load bearing platform member.
In accordance with the above-mentioned third feature, when the threaded rod is rotated in a clockwise direction so as to erect each pair of lower arms and upper arms around the lower pivots and the upper pivots respectively in order to erect the collapsed jack, since the lower sector gears formed on the outer peripheries of the inner ends of the lower arms rotate at the same time so as to ascend the lower racks, the upper base member having the lower pivots lifts relative to the lower base member having the lower racks, and since the upper sector gears formed on the outer peripheries of the inner ends of the upper arms rotate at the same time so as to push up the upper racks, the upper load bearing platform member having the racks lifts relative to the lower load bearing platform member having the upper pivots. Therefore, the total amount of lift of the jack becomes the sum of the amount of lift of the load bearing platform due to the erection of the lower arms and the upper arms, the amount of lift of the upper base member relative to the lower base member and the amount of lift of the upper load bearing platform member relative to the lower load bearing platform member, and thus the amount of lift can be increased to a great extent in comparison with a jack of the prior art in which the amount of lift of the load bearing platform is determined only by the erection of the lower arms and the upper arms. Moreover, since it is unnecessary to specially increase the lengths of the lower arms and the upper arms, the size of the jack is not made larger.
In addition to any one of the first to the third features, the present invention fourthly provides a pantagraph-type jack, wherein the rack comprises a plurality of pins which are inserted in a vertical array on the corresponding one of the lower base member and upper load bearing platform members, and both sides of these pins are made to mesh with a corresponding pair of sector gears.
In accordance with the above-mentioned fourth feature, one rack which is shared by a corresponding pair of sector gears will suffice and thus the arrangement can be simplified.
The above-mentioned objectives, other objectives, characteristics and advantages of the present invention will become apparent from an explanation of a preferable embodiment which will be described in detail below by reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a perspective view of a pantagraph-type jack of an embodiment of the present invention.
FIG. 2
is a partially cut away front view showing a state in which the jack is collapsed.
FIG. 3
is a partially cut away front view showing a state in which the jack is erected.
FIG. 4
is a cross-sectional view taken along a line
4
—
4
in FIG.
2
.
FIG. 5
is a cross-sectional view taken along a line
5
—
5
in FIG.
2
.
FIG. 6
is a cross-sectional view taken along a line
6
—
6
in FIG.
1
.
FIG. 7
is a cross-sectional view taken along a line
7
—
7
in FIG.
1
.
DESCRIPTION OF PREFERRED EMBODIMENTS
A preferred embodiment of the present invention is explained below by reference to the attached drawings.
In
FIG. 1
a jack
10
is of the so-called pantagraph type in which four link arms are connected in a pantagraph state and comprises a base
11
, a load bearing platform
12
provided just above the base
11
, a link mechanism
13
for linking the base
11
and the load bearing platform
12
and a threaded rod
14
for lifting the load bearing platform
12
up and down by driving the link mechanism
13
.
As shown in
FIG. 2
, FIG.
4
and
FIG. 5
, the aforementioned base
11
comprises an upper base member
11
a
and a lower base member
11
b
which are connected to each other relatively movably in the vertical direction. The upper base member
11
a
is formed by bending a sheet of steel into a U shape and comprises a pair of side walls
30
,
30
which oppose to each other in the depth direction, that is to say, in the direction of the width of the jack
10
and a top part
31
which connects upper ends of the side walls
30
,
30
integrally with each other. The lower base member
11
b
is also formed by bending a sheet of steel into a U shape and comprises a pair of side walls
32
,
32
which oppose to each other in the depth direction with a gap wider than that of the two side walls
30
,
30
of the upper base member
11
a
and a bottom part
33
which connects lower ends of the side walls
32
,
32
integrally with each other, and the upper base member
11
a
is provided inside the lower base member
11
b
in a vertically movable manner. Ground supports
33
a
,
33
a
are integrally formed with the bottom part
33
of the lower base member
11
b
so as to extend from the right and left ends of the bottom part
33
.
The aforementioned load bearing platform
12
comprises a lower load bearing member
12
a
and an upper load bearing member
12
b
which are connected to each other relatively movably in the vertical direction. The lower load bearing platform member
12
a
is formed by bending a sheet of steel into a U shape and comprises a pair of side walls
37
,
37
which oppose each other in the depth direction and a bottom part
38
which connects the lower ends of the side walls
37
,
37
integrally with each other. The upper load bearing platform member
12
b
is also formed by bending a sheet of steel into a U shape and comprises a pair of side walls
37
,
37
which oppose to each other in the depth direction with a gap wider than that of the two side walls
35
,
35
of the lower load bearing platform member
12
a
and a top part
38
which links the lower ends of the side walls
37
,
37
integrally with each other, and the lower load bearing platform member
12
a
is provided inside the upper load bearing platform member
12
b
in a vertically movable manner. A load bearing channel
38
a
is formed in the depth direction on the top part
38
of the upper load bearing platform member
12
b
. When an automobile body is jacked up, the sidesill of the body is borne by the load bearing channel
38
a.
The above-mentioned link mechanism
13
comprises a pair of right and left lower arms
17
,
17
which are disposed in a V-shaped manner, the inner ends thereof being swingably connected to the upper base member
11
a
via a pair of right and left lower pivots
15
,
15
, a pair of right and left upper arms
18
,
18
which are disposed in an inverted V-shaped manner, the inner ends thereof being swingably connected to the lower load bearing platform member
12
a
via a pair of right and left upper pivots
16
,
16
, a first connecting shaft
19
a
for swingably connecting the outer ends of lower arm
17
and upper arm
18
on one side and a second connecting shaft
19
b
for swingably connecting the outer ends of lower arm
17
and upper arm
18
on the other side.
Each lower arm
17
is made from a sheet of steel and comprises a pair of side walls
26
,
26
which oppose to each other in the depth direction and a bottom part
27
which connects the lower edges of the side walls
26
,
26
integrally with each other, and the inner ends of the two side walls
26
,
26
are inserted between the side walls
30
,
32
of the upper and lower base members
11
a
,
11
b
and connected to the side walls
30
,
30
of the upper base member
11
a
via the corresponding aforementioned lower pivot
15
.
Each upper arm
18
is also made from a sheet of steel and comprises a pair of side walls
28
,
28
which oppose to each other in the depth direction and a top part
29
which connects the upper edges of the side walls
28
,
28
integrally with each other, and the inner ends of the two side walls
28
,
28
are inserted between the side walls
35
,
37
of the lower and upper load bearing platform members
12
a
,
12
b
and connected to the side walls
35
,
35
of the lower load bearing platform member
12
a
via the corresponding aforementioned upper pivot
16
.
The gap between the side walls
26
,
26
of each of the right and left lower arms
17
,
17
is made so as to be wider than the gap between the side walls
28
,
28
of each of the right and left upper arms
18
,
18
, and the outer ends of the side walls
28
,
28
of each of the two upper arms
18
,
18
are interposed between the outer ends of the side walls
26
,
26
of each of the two lower arms
17
,
17
and these outer ends are connected to each other via the first and second connecting shafts
19
a
,
19
b.
The lower pivots
15
,
15
slidably penetrate two pairs of right and left long bores
40
,
40
which are vertically elongated and are provided on each of the two side walls
32
,
32
of the lower base member
11
b
, and in order to prevent the pivots
15
,
15
from falling out they have expanded ends
15
a
,
15
a
at both ends which are in contact with the outer surfaces of the above-mentioned two side walls
32
,
32
.
The upper pivots
16
,
16
slidably penetrate two pairs of right and left long bores
41
,
41
which are vertically elongated and are provided on each of the two side walls
37
,
37
of the upper load bearing platform member
12
b
, and in order to prevent them from falling out they have expanded ends
16
a
,
16
a
at both ends which are in contact with the outer surfaces of the above-mentioned two side walls
37
,
37
.
Lower sector gears
20
,
20
;
20
,
20
which oppose to each other are formed symmetrically on the outer peripheries of the inner ends of each of the two side walls
26
,
26
;
26
,
26
of the right and left lower arms
17
,
17
, and lower racks
42
which mesh with the lower sector gears
20
,
20
;
20
,
20
are provided in the vertical direction on the lower base member
11
b
. These lower racks
42
comprise a plurality of pins
43
. . . (three pins in the illustrated embodiment) which are provided at vertically identical intervals with both ends supported on the two side walls
32
,
32
of the lower base member
11
b
, and the right and left lower sector gears
20
,
20
;
20
,
20
mesh with both the sides of these pins
43
. . . . Here, elongated hole-shaped notches
46
,
46
are provided on the two side walls
30
,
30
of the upper base member
11
a
in order to avoid interference with each of the pins
43
. . . . Each of the pins
43
. . . has expanded ends
43
a
,
43
a
at both ends which are in contact with the outer surfaces of the lower base member
11
b
in order to prevent them from falling out.
Upper sector gears
21
,
21
;
21
,
21
which oppose to each other are also formed symmetrically on the outer peripheries of the inner ends of each of both the side walls
28
,
28
;
28
,
28
of the right and left upper arms
18
,
18
, and upper racks
44
which mesh with the upper sector gears
21
,
21
;
21
,
21
are provided in the vertical direction on the upper load bearing platform member
12
b
. These upper racks
44
comprise a plurality of pins
45
. . . (three pins in the illustrated embodiment) which are provided at vertically identical intervals with both ends supported on both the side walls
37
,
37
of the upper load bearing platform member
12
b
, and the right and left upper sector gears
21
,
21
;
21
,
21
mesh with both the sides of these pins
45
. . . . Here, elongated hole-shaped notches
47
,
47
are provided on the two side walls
35
,
35
of the lower load bearing platform member
12
a
in order to avoid interference with each of the pins
45
. . . . Each of the pins
45
. . . has expanded ends
45
a
,
45
a
at both ends which are in contact with the outer surfaces of the upper load bearing platform member
12
b
in order to prevent them from falling out.
As shown in FIG.
6
and
FIG. 7
, the first connecting shaft
19
a
is made from a hollow tube and is provided at its centre with a shaft hole
22
which is orthogonal to its axis. The second connecting shaft
19
b
is solid and is provided at its centre with a threaded hole
23
which is orthogonal to its axis, one end of the threaded rod
14
is fitted rotatably into the above-mentioned axis hole
22
, and the other end of the above-mentioned rod
14
is screwed into the threaded hole
23
.
A yoke joint
24
is secured by welding to one end of the threaded rod
14
on the side corresponding to the first connecting shaft
19
a
, a thrust bearing
25
is mounted so as to adjoin the yoke joint
24
, and the threaded rod
14
can be connected to the first connecting shaft
19
a
in an axially non-movable manner by positioning the thrust bearing
25
and an extrusion
50
formed on the outer peripheral surface of the threaded rod
14
so as to be in contact with both the side surfaces of the first connecting shaft
19
a.
As shown in FIG.
4
and
FIG. 5
, recesses
48
,
49
for receiving one portion of the outer peripheral surface of the threaded rod
14
when the jack
10
is collapsed are formed on the upper wall part
31
of the upper base member
11
a
and the bottom wall part
36
of the lower load bearing platform member
12
a
, and thus it is possible to reduce the height of the collapsed jack
10
as much as possible.
Next, the operation of the present embodiment is described.
When the jack
10
is in a collapsed state as shown in
FIG. 1
(the solid line) and
FIG. 2
, by rotating the threaded rod
14
in the clockwise direction by means of a rotation tool (not illustrated) connected to the yoke joint
24
the first and second connecting shafts
19
a
,
19
b
approach each other, thereby resulting in the lower arms
17
,
17
and the upper arms
18
,
18
starting to erect around the lower pivots
15
,
15
and the upper pivots
16
,
16
respectively to lift the load bearing platform
12
.
Simultaneously, while the lower arms
17
,
17
are erecting around the lower pivots
15
,
15
, since the lower sector gears
20
,
20
rotate so as to ascend the lower racks
42
as shown in
FIG. 3
, the upper base member
11
a
having the lower pivots
15
,
15
lifts relative to the lower base member
11
b
having the lower racks
42
. While the upper arms
18
,
18
are erecting around the upper pivots
16
,
16
, since the upper sector gears
21
,
21
rotate so as to push up the upper racks
44
as shown in
FIG. 3
, the upper load bearing platform member
12
b
having the upper racks
44
lifts relative to the lower load bearing platform member
12
a
having the upper pivots
16
,
16
.
As a result, the total amount of lift of the jack
10
becomes the sum of the amount of lift of the load bearing platform
12
due to the erection of the lower arms
17
,
17
and the upper arms
18
,
18
, the amount of lift of the upper base member
11
a
relative to the lower base member
11
b
, and the amount of lift of the upper load bearing platform
12
b
relative to the lower load bearing platform
12
a
, and thus it is possible to increase the amount of lift to a great extent in comparison with that of a lack of the art in which the amount of lift of the load bearing platform
12
is determined only by the erection of the lower arms
17
,
17
and the upper arms
18
,
18
. Moreover, since there is no special need to increase the lengths of the lower arms
17
,
17
, the upper arms
18
,
18
and the threaded rod
14
, the size of the jack
10
can be prevented from increasing.
Since the lower racks
42
comprise a plurality of pins
43
. . . which are provided at vertically identical intervals and whose both ends are supported on the two side walls
32
,
32
of the lower base member
11
b
and the right and left lower sector gears
20
,
20
mesh with both sides of these pins
43
. . . , only one set of lower racks
42
which is shared by the right and left lower sector gears
20
,
20
will suffice. Since the upper racks
44
comprise a plurality of pins
45
. . . which are provided at vertically identical intervals with both ends supported on the two side walls
37
,
37
of the upper load bearing platform member
12
b
and the right and left upper sector gears
21
,
21
mesh with both sides of these pins
45
. . . , only one set of upper racks
44
which is shared by the right and left upper sector gears
21
,
21
will suffice. Thus, the arrangement can be simplified.
When the jack
10
is in an erect state, by rotating the threaded rod
14
in the reverse direction, the lower arms
17
,
17
and the upper arms
18
,
18
collapse around the lower pivots
15
,
15
and the upper pivots
16
,
16
respectively due to an action opposite to the above-mentioned action, the upper base member
11
a
descends relative to the lower base member
11
b
, the upper load bearing platform member
12
b
descends relative to the lower load bearing platform member
12
a
, and thus it is apparent that the jack
10
collapses.
The present invention is not limited to the above-mentioned embodiment and can be modified in a variety of ways without departing from the spirit and scope of the invention.
Claims
- 1. A pantagraph-type jack in which outer ends of a pair of lower arms disposed in a V-shaped manner whose inner ends are swingably connected to a base and outer ends of a pair of upper arms disposed in an inverted V-shaped manner whose inner ends are swingably connected to a load bearing platform are connected via first and second connecting shafts, and a threaded rod supported on the first connecting shaft in a rotatable but axially non-movable manner is screwed into a threaded bore provided in said second connecting shaft, wherein said base comprises an upper base member and a lower base member which are connected to each other relatively movably in a vertical direction, inner ends of said pair of lower arms are swingably connected to the upper base member via a pair of lower pivots arranged in a horizontal direction, lower sector gears are formed on outer peripheries of the inner ends of said two lower arms, and a lower rack which meshes with said lower sector gears is disposed in the vertical direction and secured on said lower base member.
- 2. A pantagraph-type jack in which outer ends of a pair of lower arms disposed in a V-shaped manner whose inner ends are swingably connected to a base and outer ends of a pair of upper arms disposed in an inverted V-shaped manner whose inner ends are swingably connected to a load bearing platform are connected via first and second connecting shafts, and a threaded rod supported on the first connecting shaft in a rotatable but axially non-movable manner is screwed into a threaded bore provided in said second connecting shaft, wherein said load bearing platform comprises a lower load bearing platform member and an upper load bearing platform member which are connected to each other relatively movably in a vertical direction, inner ends of the pair of upper arms are swingably connected to said lower load bearing platform member via a pair of upper pivots arranged in a horizontal direction, upper sector gears are formed on outer peripheries of the inner ends of said two upper arms, and an upper rack which meshes with said upper sector gears is disposed in the vertical direction and secured on said upper load bearing platform member.
- 3. A pantagraph-type jack in which outer ends of a pair of lower arms disposed in a V-shaped manner whose inner ends are swingably connected to a base and outer ends of a pair of upper arms disposed in an inverted V-shaped manner whose inner ends are swingably connected to a load bearing platform are connected via first and second connecting shafts, and a threaded rod supported on the first connecting shaft in a rotatable but axially non-movable manner is screwed into a threaded bore provided in said second connecting shaft, wherein said base comprises an upper base member and a lower base member which are connected to each other relatively movably in a vertical direction, inner ends of said pair of lower arms are swingably connected to the upper base member via a pair of lower pivots arranged in a horizontal direction, lower sector gears are formed on outer peripheries of the inner ends of said two lower arms, and a lower rack which meshes with the lower sector gears is disposed in the vertical direction and secured on said lower base member, and said load bearing platform comprises a lower load bearing platform member and an upper load bearing platform member which are connected to each other relatively movably in a vertical direction, inner ends of the pair of upper arms are swingably connected to said lower load bearing platform member via a pair of upper pivots arranged in a horizontal direction, upper sector gears are formed on outer peripheries of the inner ends of said two upper arms, and an upper rack which meshes with said upper sector gears is disposed in the vertical direction and secured on said upper load bearing platform member.
- 4. A pantagraph-type jack according to any one of claims 1 to 3, wherein said rack comprises a plurality of pins which are inserted in a vertical array on a corresponding one of said lower base member and upper load bearing platform members, and both sides of these pins are made to mesh with a corresponding pair of sector gears.
Priority Claims (1)
Number |
Date |
Country |
Kind |
12-142273 |
May 2000 |
JO |
|
US Referenced Citations (7)
Foreign Referenced Citations (1)
Number |
Date |
Country |
3-6120 |
Jan 1991 |
JP |