Note: Descriptions are shown in the official language in which they were submitted.
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Golf swim practice device
FIELD OF THE INVENTION
This invention relates to a golf swing practice device which preferably can be
removably attached to a conventional golf club and which enables a golfer who
is
practising a golf swing, to visually determine if the club face of the club
head of a golf
club is maintained in a "square" position in the backswing of the golfer,
and/or in the
initial stage of the downswing of the golfer.
BACKGROUND OF INVENTION
The use of light sources, light reflectors and light beams which are either
built
into a golf club or attached to a golf club, usually along the shaft of the
club, are well
known in the art and most commonly are employed for visually informing a
golfer if the
impact face of the club head is square to the target line at the point of
actual or imagined
golf ball impact.
One such attachment device is disclosed in US Pat. No. 5,467,991 issued Nov.
21, 1995, White, which discloses a base mounting plate which is removably
attached to
a club shaft and which supports a pair of light emitting diodes (LED's) aimed
in opposite
directions parallel to the shaft of the club.
As the beam of light emitted from the lowermost LED is offset relative to the
axis of the club shaft, the light trace which the beam makes when it impinges
the ground
is behind the head of the club head. Because of this offset, the light trace
on the ground
is not representative of the actual location of the impact face of the club
head, and
further, does not produce a straight line ground light trace in the ball
impact area due to
the rotation of the hands and club in this area.
The second LED on the White device also emits a beam of light which is offset
and parallel to the axis of the shaft, but which in this instance extends in a
direction
opposite to the first or lowermost beam. This second or upper beam, during the
latter
part of the back swing, the early part of the down swing and during follow
through, is
intended to produce a light trace on the ground which is parallel to the
desired target
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line. While White's golf swing training device is useful in assisting a golfer
in
determining if the golfer's swing is following the correct swing plane by the
two light
tracings on the ground, it is not possible through the use of the single and
offset
downwardly projecting light beam to determine if the face of the club head at
the point
of actual or imaginary ball impact is on line to the ball, "square" to the
ball or if it is
open or closed to the ball and which is commonly described as a toe-in or toe-
out
condition. Toe-in or toe-out of the face of a club head normally imparts to an
impacted
ball unwanted side spin which results in either a hook or slice.
Cunningham in L1S Pat. No. 5,470,072 issued Nov. 28, 1995, provides for two
spaced apart light sources positioned on the crown or top surface of a club
head and
which are also positioned in a plane perpendicular to the ball impact face of
the club
head. If the light tracings from the light sources (which are directed or
reflected towards
the golfer swinging the club and not the ground) appear superimposed at the
point of
actual or imaginary ball impact, it indicates to the person swinging the golf
club that the
face of the club head is square to the ball. 1-Iowever, if the two light
tracings in the
proximity of ball impact are offset one relative to the other, it is
indicative that the club
face is not square, and is either in a toe-in or toe-out condition.
Cunningham also discloses the attachment of a bar to a lower portion of the
shaft
of the club with the bar carrying light sources or light reflectors thereon,
and which
provides the golfer with the same interpretative information as given when the
light
sources are positioned on the crown of the golf head.
While Cunningham assists one in determining if the club face is square to the
ball at the point of impact, no interpretative visual information is given the
golfer about
the golfer's swing being in the correct swing plane or if the imaginary ball
which appears
to be hit square, is in fact being hit square but in an "in-to-out" or an "out-
to-in" swing
arc relative to the desired target line; thereby creating what is termed a
"push" or a
"pull". Further, no information is provided to the golfer regarding the
position of the
club during the backswing or initial periods of the down swing.
In US Patent No. 5897441 (Apthorp), an improved device is described wherein
two lasers are pointed down the club shaft towards the club head in a line
which bisects
the club face at right angles. During the down swing, the points of light
"trace" two lines
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on the ground which should appear to cross one another at the point of impact,
thus
indicating to the golfer that the club face is square to the target at the
point of impact.
Additionally, Apthorp describes a device having a third laser which emits a
beam
of light in a direction substantially coaxial with the axis of the club shaft,
but in a
direction away from the club head. During the later part of the backswing and
the initial
stages of the downswing, this third laser traces a line on the ground, and is
representative of the true plane in which the shaft of the club is located.
While
determining that the club is on the correct swing plane is of some importance
and utility,
the third laser of Apthorp does not provide any indication on the position of
the club
face during the later stages of the backswing, or the initial stages of the
downswing.
Accordingly, at or near the top of the backswing, the device of Apthorp will
indicate to the golfer whether the golf club is in the correct plane, but does
not provide
any indication to the golfer whether the club face is in an open, closed or
square
position. This can be of importance to the golfer since a open or closed club
face in the
initial portions of the downswing must be manipulated back to a square
position prior to
impact with the ball. Having the club in a square position during the later
stages of the
backswing and/or the initial stages of the downswing can minimize the amount
of
manipulation required to have the club face in a square position at the point
of impact
with the ball.
SUMMARY OF THE INVENTION
It is an object of the present invention, therefore, to provide a golf swing
practice
device which can provide feedback to the golfer to indicate whether the golf
club is in
an open, square, or closed position during the later stages of the backswing
or the initial
stages of the downswing.
Accordingly, the present invention provides a golf swing practice device which
can be preferably removably attached to the shaft or to the grip on the shaft
of
conventional golf club (either "woods" or "irons"), and which enables a
golfer, through
light tracings on the ground, to determine if the face of the club head is in
a square
position during the later stages of the backswing or the initial stages of the
downswing.
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As discussed above, the light tracings generated by the White, Cunningham or
Apthorp practice devices, does not provide this type of interpretative
information.
In order to achieve the foregoing, and in accordance with one embodiment of
the
present invention, a golf swing practice device is provided for use with a
golf club
having a club head and a club shaft, comprising: a carrier member having at
least one
light source which is mounted so as to project a beam of light in a direction
away from
the club head so that said light source projects a beam of light on the ground
during the
later stages of the backswing and during the initial stage of the downswing,
and wherein,
said light source projects a relational image on the ground, which relational
image
provides an indication of the position of the club face of the club head.
Preferably, the light source is mounted in a position which is essentially
parallel
to, and preferably, essentially coaxially with, the club shaft.
DESCRIPTION OF THE INVENTION
The relational image projected on the ground may be any of a series of shapes
and sizes, such as an image of the club head, a triangle, an oval, or the
like, but most
preferably is a line of light projected from a single light source. A circular
pattern would
not be usable since it would not provide feedback regarding the position of
the club face,
unless some other markings were included. Thus, the term "relational" is used
to
describe an image which can be used to provide information on the orientation
of the
light source, and thus, the position of the club head.
Alternatively, two or more light sources could be used to project two or more
points of light in a distinctive pattern so as to create a relational image
which would also
provide an indication of the position of the club face during the later
portions of the
backswing or the initial portions of the downswing.
Preferably, the light source projects an image of a line. At address, it has
been
found that a preferred arrangement has a line of light which projects a line
of light which
extends up the chest of the user, and which is essentially parallel to the
spine of the user.
As the club rotates around the user in a golf swing (when the golf club is
kept on plane,
and square to the target), the relational image from the light source will
project an image
on the ground during the later stages of the backswing, or during the initial
stages of the
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downswing. For example, when the lead arm (i.e. the arm of the user closest to
the
target) of the user is essentially parallel to the ground on the backswing or
downswing,
the light source will, when the club is on the correct plane, project an image
on the
ground, which will fall at or near the ball, or the target line of the
intended line of flight
of the ball (which includes an extension of the line of flight, behind the
ball).
With the preferred light source arrangement wherein the light source projects
a
line of light essentially parallel to the spine of the user at address, the
light source will
project a line of light which is essentially parallel to the target line when
the lead arm of
the user is parallel to the ground. Thus, when a golf swing has been executed
wherein
the club face is kept square to the target, and the club is kept on line, the
light source
will project a line on the ground which is parallel to, and preferably on, the
intended
target line, or extension thereof, of the ball flight.
Should the club face be open or closed during the backswing or the downswing,
the line of light will not be parallel to the intended target line.
Any suitable sources of light can be employed as the light source or sources.
This includes devices such as, for example, light emitting diodes (LED's) or
lasers
provided they emit sufficiently strong discrete beams of light to illuminate
the ground.
Preferably, however, the light sources are laser light sources, and preferably
are laser
diodes which have a wave length of 635-688 mm and maximum output of 5 mW, such
as those used in known laser pointers used for instructional purposes. These
devices
have been found to be ideally suited for use in the present invention since
the visual
beam is red and is not generally affected by ambient light.
The golf swing practice device of the present invention is preferably adapted
to
be releasably attached to any standard golf club, which can include golf clubs
generally
described by golfers as putters, irons or woods. However, the golf swing
practice device
of the present invention can be permanently attached to a golf club in order
to provide a
practice club which would generally be unsuitable for use during a game of
golf (since
its use would violate the current rules of the game). Alternatively, the golf
swing
practice device could be attached to a foreshortened golf club, or even to a
foreshortened
golf shaft with grip without a club head (in which case the club head would be
imaginary). In this fashion, a practice device is provided which could be used
in height
restricted locations while still providing feedback on the position of the
(imaginary) club
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face. Thus, the term golf club is used to include these options of a dedicated
golf swing
training device, and a foreshortened club, with or without a club head.
The device of the present invention can be used in combination with other
known devices used for indicating the position of the club face at impact,
such as the
devices of White, Cunningham, or most preferably, the device of Apthorp,
described
hereinabove. Thus, the device of the present invention can be used in
combination with
a device having a carrier member which can be removably attached to a shaft of
a golf
clubs and which is preferably attached to the lower portion of the hand grip
which is
itself mounted on the free end of the shaft. First and second lower light
sources,
preferably lasers, are mounted on the carrier and so positioned thereon to
emit therefrom
two spaced apart and parallel discrete beams of light in a direction towards
the head of
the club. The two light sources on the carrier are located on either side of
the shaft when
the carrier is attached to the shaft or grip, and are so positioned that the
two light beams
emitted therefrom together lie in a plane which bisects a club face of the
club head at a
right angle.
Again, the golf club of this combined golf swing practice device could be a
dedicated golf swing training device with all light sources permanently or
releasably
attached, or could be a foreshortened club with or without a club head. In the
embodiment where a club head is not present, an additional light source might
be used
to project an image such as a club head, or a line, which would represent the
position of
the club face.
Further, an alignment light source could be added to the device of the present
invention which would provide a light beam projected onto the ground, at
address, that
would provide an indication of whether the club face was square at address,
and provide
an indication of whether the device of the present invention was properly
mounted on
the golf club. This additional alignment light source would also project an
image onto
the ground such as, for example, a line or the image of a club face, or the
like.
Additionally, the device of the present invention can be used in combination
with a mat or other device which provides one and preferably two spaced apart
parallel
lines on the ground, which represent the desired target line a hit ball should
follow.
These lines can be usefully employed in interpreting the image projected onto
the
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ground, in order to determine whether the club face is open, square, or closed
during the
later stages of the backswing, or the initial portions of the downswing.
Due to mounting considerations, the carrier member of the device of the
present
invention is preferably attached to the golf club so as to minimize any
interference with
the golfer's grip on the club. For example, the carrier member might simply
"clamp" on
to the free or proximal end of the grip, or an extension thereof, or may be
clamped onto
the lower end of the grip, or the upper part of the exposed shaft, and also
connected to
the free or proximal end of the shaft by elongated connection means which
connects the
carrier member to a hole which is invariably located in the free end of the
hand grip
attached to the shaft.
Other features of the present invention, as well as other objects and
advantages
attendant thereto, are set forth in the following description and the
accompanying
drawings in which like reference numerals depict like elements.
DESCR1PTION OF DRAWINGS
In the accompanying drawings, an embodiment of the golf swing practice device
of the present invention and its use are described, together with comments on
how the
light tracings on the ground can be used for interpretative purposes, wherein:
FIG. 1 is a perspective view of a preferred embodiment of the practice device
of
the present invention, including the positioning of the three light sources
when the
device is attached at two locations to a hand grip of a golf club;
FIG. 2 is a top plan view of the upper light source of the device of Fig. 1;
and
FIG. 3 is a rear illustrative view of a golfer's swing arc and the ground
tracing of
the upper light source relative to the desired target line; and
DETAILED DESCRIPTION OF DRAWINGS
The golf swing practice device of the present invention is preferably used in
combination with a practice device which provides an additional indication of
the club
head position at impact, such as the device of Apthorp described in US Patent
No.
5897441. Accordingly, the golf swing practice device 1 shown in FIG. 1 is
essentially
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identical to the practice device described by Apthorp, with the exception of
the upper
light source.
Practice device 1 is illustrated relative to its mounting location on the hand
grip
42 of golf club 40; the golf club 40, golf club shaft 41 and hand grip 42
being shown in
broken line.
In accordance with the device of Apthorp, practice device 1 consists of a
carrier
member 2 having two spaced apart light sources mounted thereon and which are
also
illustrated in broken line at 3 and 4, and which respectively direct parallel
beams of light
indicated by lines 5 and 6 towards the distal end of shaft 41.
Carrier member 2 is made up from a C-shaped section 7 and limb elements 8 and
9 which are each respectively attached to a free end of C-shaped section 7.
The opposed
and inwardly directed limbs of elements 8 and 9 at their respective free ends
are
provided with curved clasping elements 10 and 1 1 which serve to removably
attach
carrier member 7 to shaft 4. The spatial distance between the clasping
elements can be
varied so that the carrier can be readily attached and removed from hand grip
42. To this
end, curved clasping element 11 can remain fixed to the limb of element 8
while
clasping element 10 is permitted to move inwardly and outwardly by simply
rotating
tubular sleeve 12 which is threadedly connected to element 8 in a manner which
is well
understood in the art.
As illustrated, limbs 8 and 9 at the end of C-shaped section 7 also each
extend
downwardly and have internally located therein, light sources 3 and 4
illustrated in
broken line which emit discrete beams of light depicted by lines 5 and 6.
Carrier member 2 is also attached to the upper or proximal end of the golf
club
employing a second elongate connector 13 which at one end is fixed to carrier
member 2
as shown in FIG. 1 and which at its other end, terminates at projecting pin 14
which can
be inserted in a hole 15 which is located in the top end of the hand grip 42
as illustrated.
Connector 13 along its major length is spaced from grip 42 a sufficient
distance to
enable the clasping of hand grip 42 without interference.
Second connector 13 at its end which attaches to grip 42 also preferably is
used
to support an upper light source 16 which is oriented so as to be coaxial with
shaft 41,
and which projects direct a discrete line of light away from the club head in
a direction
opposite to parallel light beams 5 and 6. In Fig. 2, the light source 16 is
shown in detail
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so as to indicate that it contains a slot 21 which would provide for a line of
light to be
emitted from the light source. As described earlier, other images could be
used, and the
images could be rotated, and/or replaced with other images which would provide
a
relational image to be projected.
As shown in Fig. 1, the light projected from upper light source 16 is
projected
through slot 21 to provide for the projection of light generally shown by
broken lines 22
and 23, to produce a line of light 24 which is projected from the upper light
source. In
the embodiment shown, the line of light 24, would be projected on the chest of
the user,
when the device was at address, in a line essentially parallel to the spine of
the user.
The power supply for light sources 3, 4 and 16 can comprise battery power with
two such batteries being illustrated in series and located internally of the
second
connector 13 as illustrated in broken line at 18. Switch 19 is used to turn
the power
supply for the light sources on and off in a well known manner.
Use of the parallel beams of light 5 and 6, emitted from light sources 3 and
4, is
described in detail in US 5897441, the contents of which are hereby
incorporated by
reference. No further discussion of their use is necessary for the purposes of
the present
invention.
In Fig. 3, the ground tracking of the line of light 24, is illustrated. A
golfer 30
using the practice device 1 of the present invention is shown in a position
near the top of
the backswing (which is essentially identical to the position of the golfer at
the initial
stages of the downswing). The preferred plane of the swing is generally
depicted as 31.
Although some variation from this ideal plane is likely, particularly at the
initial stages
of the swing, it is a good visual concept to follow this plane 31 as closely
as possible
throughout the swing.
When the golfer reaches the position of the swing shown in Fig. 3, light
depicted
as 22 to 23 is emitted from the upper light source 16 so as to produce a line
of light 24
on the ground. If the club head is square to the target, line 24 will be
essentially parallel
to the line of the target. As the golfer completes the backswing, the line of
light will
move further back behind the golfer, but will remain on a line parallel to the
line of the
target.
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It should be noted that this line of light 24 can be observed by the golfer,
or by a
second party, who can use the information to determine the position of the
club face
during the backswing.
As the golfer starts the downswing, the light of light 24 will move from
behind
the golfer, and will pass through the golf ball 25, and then move in front of
ball 25. At
all times, however, the line of light should remain essentially parallel to
the target line,
and preferably will remain on the target line.
The tracings of upper light source 16 (and light beams 5 and 6) may be merely
projected on to the ground. However, it is preferred that the light be
projected on to a
thin practice strip or runway such as a length of plastic sheet material 20 or
the like
having spaced apart parallel markings thereon (86 and 90), and which can be
orientated
so as to represent the desired target line. With the use of this practice
strip 20, it is easier
for the golfer or an observer to confirm that the line of light 24 remains
between and
parallel to, lines 86 and 90.
Thus, it is apparent that there has been provided, in accordance with the
present
invention, a golf swing practice device, which fully satisfies the means,
objects, and
advantages set forth hereinbefore. Therefore, having described specific
embodiments of
the present invention, it will be understood that alternatives, modifications
and
variations thereof may be suggested to those skilled in the art, and that it
is intended that
the present specification embrace all such alternatives, modifications and
variations as
fall within the scope of the appended claims.
Further, it will also be appreciated that while I have advanced a particular
form
of construction which is intended to achieve the end objects of my invention,
various
alterations and changes can be made to it which do not depart from the spirit
or scope of
my invention.
Additionally, for clarity and unless otherwise stated, the word "comprise" and
variations of the word such as "comprising" and ''comprises", when used in the
description and claims of the present specification, is not intended to
exclude other
additives, components, integers or steps.
