Information
-
Patent Grant
-
6758761
-
Patent Number
6,758,761
-
Date Filed
Monday, July 8, 200222 years ago
-
Date Issued
Tuesday, July 6, 200420 years ago
-
Inventors
-
-
Examiners
- Garbe; Stephen P.
- Legesse; Nini F.
Agents
-
CPC
-
US Classifications
Field of Search
US
- 473 326
- 473 333
- 473 463
- 473 457
- 473 226
- 473 437
- 446 419
- 446 227
- 446 404
- 446 26
- 446 267
- 446 400
- 446 402
-
International Classifications
-
Abstract
A sports swing training device comprising a grip, a shaft and a head used in practice of swing form of golf club or baseball or softball bat, wherein a hollow space is formed in the head and is partially filled with a liquid such as water or a solid material such as sand or small pellets.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sports swing training device used for training in golf swing and/or baseball bat swing.
2. Description of the Related Art
U.S. Pat. No. 4,614,343 discloses a golf swing training device comprising a grip and a shaft constructed similarly to those parts of a real golf club, and a head made in a unique construction different from that of a real golf club. This training device has a metal bar called click finger provided in a locked state in the head, so that the click finger is unlocked so as to fall and make a click sound when the centrifugal force of a swinging motion is higher than a predetermined level.
With the golf swing training device disclosed in the U.S. Pat. No. 4,614,343, however, the click finger is unlocked and makes a click sound whenever the centrifugal force generated by the swinging motion of a golf club is higher than a predetermined level even in an unsatisfactory form, it is not effective in correcting the swing form.
U.S. Pat. No. 5,634,856 discloses a sports swing training method and apparatus that has a weight housed freely movably in a tubular body. This training apparatus is designed so that the weight moves and strikes a distal end of the tubular body when the head portion reaches an impact point on a ball in a satisfactory swing form.
The sports swing training apparatus disclosed in the U.S. Pat. No. 5,634,856 employs a bar-shaped weight, however, and there has been such a problem that the sports swing training apparatus cannot be made in a shape similar to a real golf club or a baseball bat.
SUMMARY OF THE INVENTION
The present invention aims at solving the drawbacks of the golf swing training devices of the prior art, and provides a swing training device that enables it to reliably and easily acquire a good swing form of not only golf club but also baseball or softball bat.
The present invention also aims at providing a sports swing training device that can be made in a shape substantially similar to that of a real golf club or a baseball bat.
In order to achieve the object described above, as a first feature, the invention provides a sports swing training device that has a grip, a shaft and a head and can be used in the practice of golf club swing or bat swing of baseball or softball, wherein the head has a hollow space therein with the hollow space being partially filled with a liquid such as water or a solid material such as sand or pellets.
According to the first feature, the user can master the proper swing form of golf club or baseball or softball bat, while listening to the sound generated by the liquid or pellets that partially fill the hollow space and checking the position where the sound is produced.
The user can also correct the swing form by checking the sound generated during the swing and the position where the sound is produced.
In addition to the first feature described above, the sports swing training device of the invention has such a second feature that the device is formed similarly to a golf club as a whole, wherein the head of the club has a hollow space therein with the hollow space being partially filled with a liquid such as water or a solid material such as sand or small pellets.
According to the second feature, the invention enables it, in addition to the operation and effect of the first feature, to correct one's golf swing form by checking the sound generated by the liquid or pellets that partially fill the hollow space generated during the swing and the position where the sound is produced, while operating the sports swing training device in a similar way to that of a real golf club.
Although the sports swing training device cannot be used in an official game, one can use the sports swing training device as a golf club when playing on a golf course and correct one's swing form.
When used as a golf club, the sports swing training device can also provide secondary impact due to the liquid or solid material contained in the hollow space, in addition to the impact generated by the face of the club head.
In addition to the first feature described above, the sports swing training device of the invention has such a third feature that the device is formed like a baseball or softball bat as a whole, wherein the head portion of the bat has a hollow space therein with the hollow space being partially filled with a liquid such as water or a solid material such as sand or small pellets.
According to the third feature, the invention enables it, in addition to the operation and effect of the first feature, to correct one's bat swing by checking the sound generated during the swing and the position where the sound is produced, while operating the sports swing training device in a similar way to that of a real baseball or softball bat.
Although the sports swing training device cannot be used in an official game, one can use the sports swing training device as a real bat when playing in a practice game and correct one's batting form. When used as a bat, the sports swing training device also provides secondary impact due to the liquid or solid material contained in the hollow space when hitting a ball.
As a fourth feature of the invention, the sports swing training device is formed in a cylindrical or ring shape as a whole so as accommodate a baseball bat or a golf club fitted detachably in the central hole, while the cylindrical or ring-shaped body has a hollow inner space hollow space therein with the hollow space being partially filled with a liquid such as water or a solid material such as sand or small pellets.
According to the forth feature of the invention, with the sports swing training device attached to a baseball bat or a golf club freely detachably, the user can master the proper swing form of golf club or baseball or softball bat, while listening to the sound generated during the swing motion and checking the position where the sound is produced.
As a fifth feature, the invention provides a sports swing training device that has a grip, a shaft and a head and can be used in the practice of golf club swing or bat swing of baseball or softball, wherein whistles that sound when air flows therein are provided in the grip and the head, so that the whistle provided in the grip is caused to sound by air flow generated therein when the grip is moved down swiftly in down swing, and the whistle provided in the head is caused to sound by air flow generated therein when the head moves swiftly.
According to the fifth feature, the user can master the proper swing form of golf club or baseball or softball bat, by checking to see whether the whistles installed in the grip and in the head make sound or not and whether the sound is proper or not. The user can also check his or her swing form by listening to the sounds of the two whistles during the swing motion.
As a sixth feature of the invention, in addition to the fifth feature described above, the sports swing training device has the whistles installed in the grip and in the head that make different sounds.
According to the sixth feature, in addition to the operation and effect of the fifth feature, the user can check to see whether his or her down swing form and the trajectory of the head before impact are good or not by listening to the different sounds.
As a seventh feature of the invention, the sports swing training device is formed in a cylindrical or ring shape as a whole so as to accommodate a baseball bat or a golf club fitted detachably in the central hole, while the cylindrical or ring-shaped body has whistle that sounds when air flows therethrough.
According to the seventh feature, with the sports swing training device attached to a baseball bat or a golf club freely detachably, the user can easily master the proper swing form of golf club or baseball or softball bat, while listening to the different sounds of the whistle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
shows a first embodiment of the sports swing training device of the invention; FIG.
1
(A) in a perspective overview and FIG.
1
(B) in a sectional view of a key portion.
FIG. 2
shows a preferable trajectory of golf swing.
FIG. 3
explains a swing motion when the sports swing training device according to the first embodiment of the invention is used for training in golf swing.
FIG. 4
shows variations of the first embodiment of the invention, FIG.
4
(A), FIG.
4
(B) and FIG.
4
(C) showing partially cutaway views of key portions of the sports swing training devices.
FIG. 5
shows a second embodiment of the sports swing training device of the invention, FIG.
5
(A) showing an overview and FIG.
5
(B) showing a sectional view of a key portion.
FIG. 6
shows a third embodiment of the sports swing training device of the invention, FIG.
6
(A) showing an outside appearance and FIG.
6
(B) showing a sectional view.
FIG. 7
shows a variation of the third embodiment of the invention in an overview of the sports swing training device being attached to a golf club.
FIG. 8
is a detailed drawing of the sports swing training device shown in FIG.
7
.
FIG. 9
shows a fourth embodiment of the sports swing training device of the invention, FIG.
9
(A) showing an overview of a golf swing training device and FIG.
9
(B) showing an overview of a sports swing training device for baseball or softball.
FIG. 10
shows an outside appearance of a fifth embodiment of the sports swing training device of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first embodiment shown in
FIG. 1
will first be described below. Numeral
10
denotes a grip of the sports swing training device,
20
denotes a shaft and
30
denotes a head.
The head
30
has a hollow space
31
formed therein, with the hollow space
31
being partially filled with a content
32
comprising a solid material in the form of small pellets. The content
32
may be also a solid material such as sand or a liquid such as water.
The state of partial filling refers to the state of the content
32
filling the hollow space
31
not to the capacity thereof. Specifically, the content preferably occupies a half the capacity or a slightly smaller portion of the hollow space. This is because the spirit of the invention rests in that the head
30
work like the percussion instrument maraca through the combination of the hollow space
31
and the content
32
.
In the first embodiment, the grip
10
and the shaft
20
have shapes and dimensions similar to those of a real golf club, and the head
30
also has a shape similar to that of the head of a golf club, so that the sports swing training device is similar to a golf club in shape, dimensions, weight and balance.
It is not necessary to make the head
30
in the same shape as the head of a real golf club, and the head
30
may simply be the distal end of the shaft
20
being expanded or have other shape, as long as the head has the hollow space that contains the content.
Taking reference also to FIG.
2
and
FIG. 3
, operation of the sports swing training device used in training of golf swing will be described below. The motion of golf swing generally consists of a sequence of addressing (A), back swing (B), top swing (T), down swing (D), impact (I) and follow through (F).
The back swing (B) forms a relatively large arc, as the shoulder, arms and the club move in coordination.
During the down swing (D) that follows the top swing (T), it is said to be a good practice to pull down the shaft
20
while keeping the shaft in a vertical attitude as show in FIG.
3
. When moving from the down swing (D) to the impact (I), the grip
10
is returned to the position of addressing (A), so that the head
30
is turned rapidly to impart a strong impact to the golf ball.
Positions of the sports swing training device in a desirable swing form are shown in FIG.
3
.
In the path from the top swing (T) position to the down swing (D) position, the head
30
is directed vertically upward, and the shaft
20
is pulled down while keeping the shaft
20
in the vertical attitude, and therefore no centrifugal force is applied to the golf club till the down swing (D) position is reached. Thus during the desirable down swing motion, the content
32
provided in the hollow space
31
of the head
30
rests on the shaft
20
side due to the gravity that is predominant over the centrifugal force.
As the grip
10
is turned at a transitory position (E) between the down swing (D) and the impact (I), the head
30
moves swiftly resulting in a strong centrifugal force. Thus the content
32
moves quickly in the hollow space
31
from the shaft
20
side to the distal end so as to hit the inner surface on the distal end and make a sound. This action is similar to that of a maraca. That is, clear sound is produced only when the content
32
moves swiftly.
In case the user is a beginner incapable of swinging a golf club satisfactorily, he or she is likely to make a bad motion in the down swing (D) from the top swing (T) while keeping the shaft in vertical attitude, in a form called the hammer swing without keeping his or her arms tight on the body. In such a motion, the content
32
in the hollow space
31
of the head
30
begins, at the start of the swing, to move slowly due to the centrifugal force of the hammer swing that follows the top swing, until the content reaches the distal end of the hollow space
31
without making a clear sound. Thus the swing motion would be finished at the impact (I) without making a clear sound.
Therefore, the sports swing training device of the invention does not make a sound unless the sports swing training device is swung down in a correct motion of the down swing (D) from the top swing (T) to the impact (I) in a proper form.
Thus the user can acquire the proper swing form by correcting the motion until the sound is heard when the sports swing training device is swung down properly.
FIG.
4
(A), FIG.
4
(B) and FIG.
4
(C) show variations of the first embodiment of the invention, where the head
30
as well as the grip
10
and the shaft
20
of the sports swing training device are made in appearances not distinguishable from those of a real golf club.
FIG.
4
(A) shows the head
30
of the sports swing training device made similarly to the iron head of an ordinary golf club, while the hollow space
31
is formed in the head
30
, with the hollow space being partially filled with the content
32
so that the sports swing training device can be used for training in the swing of iron club.
FIG.
4
(B) shows the head
30
of the sports swing training device made similarly to the wood head of an ordinary driver club, while the hollow space
31
is formed in the head
30
, with the hollow space being partially filled with the content
32
so that the sports swing training device can be used for training in the swing of wood club.
In case the head
30
as well as the grip
10
and the shaft
20
are made similarly to those of a real golf club, as described above, swing motion can be practiced by using the sports swing training device just in the same way as a real golf club. Although the sports swing training device cannot be used in an official game, one can enjoy playing on a golf course using the sports swing training device. In this case, the sports swing training device may well be called a golf club. The present invention includes the sports swing training device that can be used as a golf club, in the scope of the invention.
In case the sports swing training device is used as a golf club when playing on a course, the impact of the head
30
generated when hitting a ball can be enhanced by the content
32
provided in the hollow space
31
. That is, when the head
30
hits the ball on the face thereof, the content
32
provided in the hollow space
31
hits the inner wall of the hollow space
31
on the face side by inertia, thereby imparting a secondary impact to the golf ball. This results in an increased flying distance of the golf ball.
The secondary impact can be increased by increasing the weight of the content, for example by using metal balls of higher specific gravity as the content
32
.
FIG.
4
(C) shows the head
30
of the sports swing training device made similarly to the wood head of an ordinary driver club similarly to FIG.
4
(B), except for the hollow space
31
in the head
30
located higher than in the case of FIG.
4
(B). By varying the vertical position of the hollow space
31
in this way, it is made possible to change the position of imparting the secondary impact to the golf ball when the content
32
hits the inner wall of the hollow space
31
. Thus the take-off angle of the golf ball can be adjusted.
FIG. 5
shows the second embodiment of the sports swing training device of the invention. The sports swing training device according to this embodiment comprises a grip
100
similar to the grip of a bat, a shaft
200
similar to the middle portion of a bat and a head
300
similar to the head portion of a bat, in a constitution similar to that of a baseball or softball bat as a whole.
The head
300
has a hollow space
310
formed therein, with the hollow space
310
being partially filled with a content
320
comprising small pellets. The content
320
may be either a solid material such as sand or a liquid such as water.
Swing motion of a bat has a common factor with the golf swing, and it is said that good practice is to pull down the bat (shaft
200
) from the top position (waiting position of the bat ready for swing) while being directed vertically upward, followed by turning of the grip so as to move the head
300
, thereby imparting a strong impact to the ball.
Thus during the desirable down swing motion and the turning of the grip, the head
300
of the bat moves swiftly resulting in a strong centrifugal force at a transitory position between the down swing and the impact. At this time, the content
320
moves swiftly from the shaft
200
side to the distal end in the hollow space
310
, and hits the inner wall at the distal end so as to make sound.
In the case of a swing form called the hammer swing carried out without with keeping his or her arms tight on the body, the content
320
moves slowly within the hollow space
310
from the start of swing toward the distal end, without with making a clear sound when the impact position is reached.
Thus the user can acquire the proper form of bat swing by correcting the motion until a clear sound is heard when the impact position is reached.
The training device for bat swing may also have a slender grip and a slender shaft similar to those of a golf club, although the head must be concentric with the shaft at the distal end of the shaft. The head must not be eccentrically connected with the shaft as in a golf club.
FIG.
6
(A) and FIG.
6
(B) show the third embodiment of the sports swing training device of the invention. This embodiment provides a simplified sports swing training device, that is fitted detachably on a bat for use in a waiting circle or other places for the purpose of training in bat swing.
The sports swing training device is formed in a cylindrical or ring shape as a whole and the body
40
has a central hole
43
that accommodates a bat near the head portion
300
of the bat, with a hollow space
41
formed in the body
40
. The hollow space
41
is partially filled with a liquid such as water. The content
42
may also be a solid material such as sand or small pellets. The body
40
may have a capped charging port
44
through which the hollow space
41
can be filled with the content
42
or emptied. The charging port
44
enables it to fill the hollow space
41
with the content
42
such as water when necessary, and empty the content
42
when unnecessary. Weight of the bat can also be changed by adjusting the quantity of the content
42
.
When the simplified sports swing training device of this embodiment is fitted near the head
300
of a bat and used in the practice of bat swing, a sound is generated at the position of impact in a good swing, similarly to the case of the second embodiment described in conjunction with FIG.
5
. Thus the user can correct his or her swing form into a proper form, and verify the swing form.
FIG.
7
and
FIG. 8
show variations of the simplified sports swing training device according to the third embodiment of the invention described in conjunction with FIG.
6
. This embodiment is a simplified sports swing training device that can be attached on a golf club, at the distal end of the shaft
20
near the base of the head
20
as shown in
FIG. 7
, and used for training in golf swing.
Similarly to that shown in
FIG. 6
, the body
40
formed in cylindrical or ring shape has a hollow space, that is not shown, with the hollow space being partially filled with a liquid such as water not shown, and the central hole
43
to accommodate a golf club.
The body
40
has clamp pieces
44
and clamp rings
45
shown in
FIG. 8
, for example, as means for fastening the body on the shaft
20
of the golf club. The clamp pieces
44
are provided in plurality (four in the drawing) in such a constitution as can be moved in the radial direction (X direction) toward and away from the shaft
20
that is fitted in the central hole
43
. Clamping effect can be made more reliable by making the bearing portions
44
a
of the clamp pieces
44
, that contact with the shaft
20
, from rubber. Numeral
46
denotes stoppers for the clamp pieces
44
.
With the clamp pieces
44
being pressed against the shaft
20
from around, the clamp rings
45
are moved in the axial direction (Y direction) thereby to fasten the clamp pieces
44
on the body
40
.
The means for fastening the body
40
on the shaft
20
is not limited to the clamp pieces
44
and the clamp rings
45
.
Such a constitution may also be employed as hollow space (
31
,
310
) and content (
32
,
320
) are provided also in the grip (
10
,
100
) as well as in the head (
30
,
300
). This constitution makes such an effect as a sound is made by the content (
32
,
320
) hitting in the grip (
10
,
100
) during the down swing and another sound is generated by the content (
32
,
320
) in the head (
30
,
300
) near the impact point, when the golf club or bat is swung in a proper form.
FIG. 9
shows a fourth embodiment of the sports swing training device of the invention, (A) showing the sports swing training device furnished as a sports swing training device for golf, comprising a main body made in the shape of a golf club as a whole that has a grip
10
, a shaft
20
and a head
30
, wherein whistles
51
,
52
are provided in the grip
10
and the head
30
. FIG.
9
(B) shows the sports swing training device furnished as a bat swing training device for baseball or softball, comprising a main body made in the shape of a bat as a whole that has a grip
100
, a shaft
200
and a head
300
, wherein whistles
51
,
52
are provided in the grip
100
and in the head
300
.
The whistles
51
,
52
are made so as to sound when air flows therethrough. The whistles
51
,
52
can be provided in the grip
10
and the head
30
, and in the grip
100
and the head
300
, respectively.
When the sports swing training device having the shape of golf club or baseball bat having the whistle
51
provided in the grip
10
,
100
is swung, a sound is generated by air introduced through the end of grip
10
a
,
10
a
and flowing through the whistle
51
, as the grip
10
,
100
is moved swiftly downward with the end of the grip
10
a
,
100
a
directed downward. For example, such a constitution may be employed as an aperture
61
a
is formed in the grip
10
a
,
100
a
so as to form an air passage
61
in the grip
10
,
100
, while the whistle
51
is installed amid the air passage, so that the air that has passed through the whistle
51
flows through the aperture
61
b
to the outside. The whistle
51
is adjusted in advance so as to make sound only when the grip
10
,
100
is moved swiftly downward with the end of the grip
10
a
,
100
a
directed downward.
When the sports swing training device having the shape of golf club or baseball bat having the whistle
52
provided in the head
30
,
300
is swung, a sound is generated by air flow generated as the head
30
,
300
is moved swiftly.
In the case of the sports swing training device having the shape of golf club, such a constitution may be employed as apertures
62
a
,
62
b
are formed in the head
30
so as to form an air passage
62
that penetrates the head in the direction of swing, while a whistle
52
is installed in the air passage
62
. The whistle
52
may also be fixed on the outside of the head
30
so as to allow the air to pass in the direction of swing.
In the case of the sports swing training device having the shape of baseball bat, such a constitution may be employed as the aperture
62
a
is formed in the side face of the head
300
so as to form the air passage
62
in the head
300
, while the whistle
52
is installed in the air passage
62
. The air that has passed through the whistle
52
is caused to flow out of the bat through another side face
62
b
of the head
300
or the distal end of the head
300
. The aperture
62
a
provided on the side face of the head
300
may also be provided in plurality around the head
300
as air inlet holes. The whistle
52
attached on the head
300
of the bat may be provided in plurality around the head
300
so that the bat can be held at any angular position around the axis.
With the whistles
51
,
52
provided in the grip
10
,
100
and the head
30
,
300
as described above, the whistle
51
sounds as proper air flow passes through the whistle
51
when proper down swing is made. When the head
30
,
300
is moved swiftly following the proper down swing, the whistle
52
sounds due to air flow therethrough. The whistle
51
does not sound when the down swing is not made properly. The whistle
52
does not sound also when the head
30
,
300
is not moved swiftly.
The sound of the whistle
51
provided in the grip
10
,
100
and the sound of the whistle
52
provided in the head
30
,
300
may be made different from each other, such as sounds of different tones. With the different sounds, wrong portion of the swing form can be identified.
FIG. 10
shows a fifth embodiment of the sports swing training device of the invention. This embodiment provides a simplified sports swing training device similar to that described in conjunction with
FIG. 6
, that is fitted detachably on a baseball bat for use in a waiting circle or other places for the purpose of training in bat swing.
The sports swing training device of this embodiment comprises a body
40
that is formed in a cylindrical or ring shape as a whole and has a central hole
43
that accommodates a bat near the head portion
300
of the bat fitted therein, while a whistle
53
is provided in the body
40
. By providing apertures
63
a
,
63
b
in the body
40
, one or more air passage
63
is formed so as to penetrate the body
40
horizontally, with the whistle
53
being installed in the air passage
63
. One or more whistle
53
may also be attached on the outside of the head
40
, so that air passes through the whistle
53
horizontally.
When the simplified sports swing training device constituted as described above attached to a bat is used in practicing bat swing, an effect similar to that of the fixed whistle
52
shown in FIG.
9
(B) can be expected from the whistle
53
of this simplified sports swing training device.
It needs not to say that the simplified sports swing training device shown in
FIG. 10
can also be used while being attached to the grip
100
of the bat, by varying the dimensions and shape. In this case, such a constitution may be employed as the body
40
is made in a shape that allows it to be freely detachably attached to the grip
100
, and the whistle
53
is attached to the body
40
so that the air flows through the whistle in the axial direction of the grip
100
(so as to operate similarly to the whistle
51
shown in FIG.
9
(B)).
The simplified sports swing training device may also be adapted for golf club. In this case, such a constitution may be employed as the shape of the body
40
shown in
FIG. 10
is changed to a shape and mechanism that allow it to be freely detachably attached near the head
30
of a golf club, and the whistle
53
is attached to the body
40
so that the air flows through the whistle in the direction of golf swing (so as to operate similarly to the whistle
52
shown in FIG.
9
(A)). When the sports swing training device is used while being attached to the grip
10
of a golf club, such a constitution may be employed as the body
40
is made in a shape and mechanism that allow it to be freely detachably attached to the grip
10
of the golf club, and the whistle
53
is attached to the body
40
so that the air flows through the whistle in the axial direction of the grip
10
(so as to operate similarly to the whistle
51
shown in FIG.
9
(A)).
Claims
- 1. A sports swing training device formed in a cylindrical shape with a central hole to accommodate a baseball bat or a golf club, said central hole being suitable for detachably engaging the shaft portion of an associated baseball bat or golf club wherein the cylindrical-shaped body is self-supporting and has a hollow space formed therein that is partially filled with a liquid or a solid material, whereby a distinct sound is generated at a position of impact when said material moves quickly in the hollow space from a proximal end to a distal end and hits an inner surface on the distal end and thereby achieves audible support for operation of the swing training device.
- 2. A sports swing training device suitable for use with a baseball bat or a golf club, said device comprises;a cylindrical or ring shaped body with a central hole, said central hole being suitable for detachably engaging the shaft portion of an associated baseball bat or golf club, said cylindrical or ring shaped body includes a hollowed out internal enclosure, said enclosure being suitable for retaining a liquid, or alternatively, a solid material, said device further comprises plural clamp pieces, with each of said clamp pieces contoured to matingly contact an external segment of said body as well as a portion of the shaft of an associated baseball bat or golf club, said clamp pieces include means for controlled radial movement along the cylindrical or ring shaped body and thereby provides a clamping effect to insure integral contact between the sports swing training device and an associated baseball bat or golf club.
- 3. A sports training device according to claim 2, wherein the cylindrical or ring shaped body further comprises at least one distinct clamping ring adapted for controlled axial rotation and thereby provide an added clamping effect between the sports swing training device and an associated baseball bat or glove.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2001-232330 |
Jul 2001 |
JP |
|
US Referenced Citations (24)