U.S. patent application number 12/675860 was filed with the patent office on 2010-09-02 for apparatus and method for controlling the hitting accuracy in the case of a golf club.
Invention is credited to Arnold Herp, Richard Jaekel.
Application Number | 20100222152 12/675860 |
Document ID | / |
Family ID | 39301812 |
Filed Date | 2010-09-02 |
United States Patent
Application |
20100222152 |
Kind Code |
A1 |
Jaekel; Richard ; et
al. |
September 2, 2010 |
APPARATUS AND METHOD FOR CONTROLLING THE HITTING ACCURACY IN THE
CASE OF A GOLF CLUB
Abstract
A device is used for controlling the accuracy with which the
striking face (16) of a golf club strikes a golf ball. It has a
plate-shaped sensor (18), which can be fastened on the striking
face (16) and by means of which the point of impact can be
localized. The sensor (18) is connected via signal lines (26) with
a measuring and computing circuit (30), which can be releasably
fastened on the shaft (12) or on the back of the head of the golf
club, is mounted, together with an electrical voltage source, in a
housing (28) and which, in the course of every hit, performs a
measuring process for determining the coordinates of the impact
point relative to the position of a predetermined reference point
(22). A radio module (34), connected with the measuring and
computing circuit (30), transmits the results of the measurements
to an evaluating device (36), like a cell phone or the such, for
the program-controlled evaluation and display of the results of the
measurements on a display screen (40).
Inventors: |
Jaekel; Richard;
(Frankfurt/M, DE) ; Herp; Arnold; (Mohrendorf,
DE) |
Correspondence
Address: |
STITES & HARBISON PLLC
1199 NORTH FAIRFAX STREET, SUITE 900
ALEXANDRIA
VA
22314
US
|
Family ID: |
39301812 |
Appl. No.: |
12/675860 |
Filed: |
September 1, 2007 |
PCT Filed: |
September 1, 2007 |
PCT NO: |
PCT/EP2007/007646 |
371 Date: |
March 1, 2010 |
Current U.S.
Class: |
473/223 ;
473/409 |
Current CPC
Class: |
A63B 69/3617 20130101;
A63B 69/362 20200801; A63B 2225/50 20130101 |
Class at
Publication: |
473/223 ;
473/409 |
International
Class: |
A63B 69/36 20060101
A63B069/36 |
Claims
1. A device for controlling the accuracy with which the striking
face of a club head of a golf club strikes a golf ball,
characterized by a plate-shaped sensor, which can be releasably
fastened on the striking face in a defined position, by means of
which in the course of striking a golf ball the exact point of the
position of the impact point in a coordinate system can be
localized by measuring an electrical voltage, which changes
proportionally to the change of the distance from the coordinates,
a housing, which can be releasably fastened on the shaft or on the
back of the head of the golf club, containing an electrical voltage
source and an electronic measuring and computing circuit, which
acts together with the sensor via signal lines, by means of which a
measuring process for determining the coordinates of the impact
point in relation to the position of a predetermined reference
point can be performed in the course of each impact on a golf ball,
and a radio module, connected with the measuring and computing
circuit, for the wireless transmission of the results of the
measurements to an evaluation device in the nature of a cell phone,
smart phone or PDA for the program-controlled evaluation and
display of the results of the measurements on its display
screen.
2. The device in accordance with claim 1, characterized in that the
plate-shaped sensor is a touchpad, with a rectangular support plate
having a first electrically conductive layer applied to its front,
which is connected along two oppositely located edge areas with
respective printed strip conductors connected to a signal line, and
with a flexible protective plate arranged in front of the support
plate, to whose back a second electrically conductive layer has
been applied which is connected along two oppositely located edge
areas with respective printed strip conductors, which are connected
to a signal line and extend transversely in respect to the strip
conductors connected with the first conductive layer, wherein the
conductive layers are separated by elastic spacers, whose restoring
force has been selected in such a way that there is a temporary
contact between the conductive layers only when a golf ball strikes
an impact point.
3. The device in accordance with claim 2, characterized in that the
protective plate is fixedly connected in a material-to-material
manner with the support plate in the edge area, except for at least
one air inlet and outlet opening.
4. The device in accordance with claim 2, characterized in that the
support plate is maximally 1 mm thick and is flexible.
5. The device in accordance with claim 2, characterized in that the
active sensor face of the sensor is approximately 45 to 55 mm wide,
and for putters approximately 20 mm high, and for clubs for
pitching and chipping 20 to 30 mm high.
6. The device in accordance with claim 1, characterized in that the
plate-shaped sensor can be releasably attached to the striking face
by means of a foil, which is adhesive on both sides.
7. The device in accordance with claim 1, characterized in that the
signal lines have a plug connection, which can be released, between
the sensor and the measuring and computing circuit.
8. The device in accordance with claim 1, characterized in that the
housing of the measuring and computing circuit can be fastened in a
frictionally connected manner to the shaft 12 via a rubber-like
contact face by means of a clamping strip.
9. A method for determining the position of the impact point of a
golf ball on the striking face of a golf club by means of a device
in accordance with claim 2, characterized in that during the time
of the contact between the conductive layers at the impact point an
electrical voltage is alternatingly applied between respective
oppositely located edge areas of one of the conductive layers, and
a voltage measurement is performed at least at one of the edge
areas of the respectively other conductive layer, and that the
voltage values are converted into coordinates of the impact point
by means of a proportionality factor.
Description
[0001] The invention relates to a device and a method for
controlling the accuracy with which the striking face of a club
head of a golf club strikes a golf ball.
[0002] In putting in particular it is important that the putter
used for this is accurately guided, so that it strikes the golf
ball with the ideal spot on the striking face, the so-called sweet
spot, taking into consideration the center of gravity. The
situation is similar in chipping and pitching.
[0003] Normally, it is only possible to detect from the result of a
multitude of putts, whether a golfer has mastered the putting
techniques and regularly strikes the sweet spot. Occasionally a
camera is used as an aid in order to optimize the sequence of
movements, but taking pictures and evaluating the film is
time-consuming and entails great costs, so that this can only be
considered to be a temporary step. Prior to each putt it is also
possible to apply a foil, which becomes discolored under pressure,
to the face of the putter, and thereafter to evaluate the sequence
of foils. This method is also much too cumbersome for being
practiced over an extended period of time.
[0004] Finally, a golf club is sold by Alan Electronics GmbH, 63303
Dreieich, internet address www.dixxgolf.de, designated "DiXX
Digital Instruction Putter", which offers the possibility of
selectively fastening a housing on the back of the club head, which
contains acceleration sensors, an electronic measuring and
evaluation device and a flat image screen, or a weight, which is as
heavy as this unit, in an exchangeable manner. The acceleration
sensors are suitable to detect several parameters of the movement
of the golf club in the course of a club swing, inter alia also the
position of the impact point on the one or the other side of the
sweet spot. However, an exact determination of the actual point on
the striking face with which the ball was struck is not possible
with such a measuring method.
[0005] It is therefore the object of the invention to provide a
device of the type mentioned at the outset, which can be attached
to a customary golf club without substantially changing its
properties, does not require interfering actions during play only
for purposes of measurement, registers the impact point on the golf
ball more exactly than up to now, and represents the recorded
results of the measurement, after having been evaluated in
accordance with a program, in a form in which they are available at
any time.
[0006] The above object is attained by the invention by means of a
device comprising [0007] a plate-shaped sensor, which can be
releasably fastened on the striking face in a defined position, by
means of which the exact point of the position of the impact point
in the course of striking a golf ball can be localized, [0008] a
housing, which can be releasably fastened on the shaft or on the
back of the head of the golf club, containing an electrical voltage
source and an electronic measuring and computing circuit, which
acts together with the sensor via signal lines, by means of which a
measuring process for determining the coordinates of the impact
point in relation to the position of a predetermined reference
point can be performed in the course of each impact on a golf ball,
and [0009] a radio module, connected with the measuring and
computing circuit, for the wireless transmission of the results of
the measurements to an evaluation device in the nature of a cell
phone, smart phone or PDA for the program-controlled evaluation and
display of the results of the measurements on its display
screen.
[0010] The plate-shaped sensor is so light and thin that it can
practically not be felt when a stroke is performed. Because of the
application to the striking face of the golf club, and not to its
back, each impact point is being registered very precisely. The
measuring and computing circuit, which can preferably be fastened
to the shaft of the golf club, increases its weight only minimally,
because it needs to perform only the functions required for
controlling the measuring processes and for determining the
coordinates of the impact point and to transmit the results of the
measurements by radio to a cell phone or smart phone, for example.
They can be stored there and evaluated by means of suitable
programs. In most cases, a cell phone, smart phone or the like, is
available anyway and is regularly taken to the golf course.
Suitable programs for evaluating the results of the measurements
can be made available via the internet for downloading to the cell
phone or smart phone. Directly following a stroke it is thus
possible to read on the display of the cell phone which point on
the striking face had connected with the ball. Then the player can
already attempt in the course of the next stroke to correct a
possible error in holding and guiding the club. Furthermore, he can
pick up the cell phone at any time, for example during train travel
or in a restaurant, and, alone or together with other golfers, can
examine the grades of accuracy of the hits collected over an
extended period of time, evaluated and represented in diagrams, for
example, compare them with other players and discuss them.
[0011] The plate-shaped sensor is preferably constructed in the
manner of a computer touchpad, with a rectangular support plate
having a first electrically conductive layer applied to its front
which is connected along two oppositely located edge areas with
respective printed strip conductors, which are connected to a
signal line, and with a flexible protective plate, to whose back a
second electrically conductive layer has been applied which is
connected along two oppositely located edge areas with respective
printed strip conductors, which are connected to a signal line and
extend transversely in respect to the strip conductors connected
with the first conductive layer, wherein the conductive layers are
separated by means of elastic spacers, whose restoring force has
been selected in such a way that there is a temporary contact
between the conductive layers only when a golf ball strikes an
impact point.
[0012] Such a touchpad has been described in U.S. Pat. No.
6,238,790 B1, for example, to which, for the sake of simplicity,
reference is made regarding the explanation of the functioning of
the above characterized sensor. However, it should be noted here
that a computer touchpad, for example on a laptop, is intended to
be fixedly mounted in the housing of the computer and is touched by
fingers relatively lightly and slowly. In contrast thereto, the
sensor of the measuring device in accordance with the invention is
mechanically stressed to a much greater degree when striking a hard
golf ball. Moreover, other demands are made on the sensor because,
in contrast to a computer touchpad, it is intended to be easily
releasable from the support surface.
[0013] It has been surprisingly shown that, in spite of the
greater, shock-like stress in comparison to a touchpad, when the
same materials are used, the solution of problems resulting from
the different conditions does not lie in a thicker, or respectively
stronger design of the sensor, but just the opposite, in a
reduction of the plate thickness. While in a touchpad of the type
mentioned, the support plate normally has a thickness of
approximately 1.6 mm, the support plate of the novel sensor can be
about half as thick, because it is supported over the entire
surface on the striking face of the golf club, so that a greater
thickness is not required.
[0014] Simultaneously with the reduction of the thickness of the
support plate, the advantage is attained that it, and with it the
plate-shaped sensor, becomes more flexible, so that it can be more
easily removed if it is fixed on the striking face of the golf club
by means of a foil, which is adhesive on both sides.
[0015] A further difference between the sensor of the proposed
measuring device and a computer touchpad consists in that the
support plate of the touchpad is provided with strip conductors on
its back, or respectively underside, and supports electronic
components. In contrast thereto, the sensor electronics of the
proposed sensor are located in the housing of the measuring and
computing circuit, which is preferably attached to the shaft of the
golf club. The thinner support plate and the transfer of the sensor
electronics to the club shaft have the further advantageous result
that the entire plate-shaped sensor only needs to have a thickness
of approximately 1 to 2 mm, so that therefore the striking face of
the golf club is only minimally displaced forward.
[0016] More than a computer touchpad, the sensor of the novel
device is exposed to changing temperatures and to moisture. It is
therefore useful that the protective plate is solidly and sealingly
connected in a material-to-material manner in the edge area with
the support plate, for example glued together with it, except for
an air inlet and outlet opening. The air inlet and outlet opening
can be covered by means of a water-tight, but air-permeable foil,
or sealed by a cover, such as in a labyrinth seal, for example, in
such a way that the sensor is at least protected against dust and
splashed water in accordance with IP54.
[0017] Tests have shown that the active sensor surface only needs
to be approximately 45 to 55 mm wide, and for putters approximately
16 to 20 mm high, for clubs for pitching and chipping 20 to 30 mm
high. Preferably the sweet spot is located in the center.
[0018] It furthermore appears to be useful that the signal lines
between the sensor and the measuring and computing circuit have a
plug connection which can be released. This permits the separate
application and replacement of the respective two units on the golf
club. Preferably, the one half of the plug connection is fixedly
attached to the housing of the measuring and computing circuit or
fixed on the support plate, while the other half of the plug
connection is located at the free end of a cable. A multitude of
embodiment variations are available for fastening this housing on
the shaft of the golf club. It may already be sufficient to fix the
housing in a frictionally connected manner by means of at least one
clamp or one clamping strap, wherein a rubber-like contact face or
intermediate layer is advantageous.
[0019] An exemplary embodiment of the invention will be described
in greater detail in what follows by means of the drawings. Shown
are in:
[0020] FIG. 1, a schematic representation of the total
configuration of the proposed device,
[0021] FIG. 2, a simplified cross section through a sensor,
[0022] FIG. 3, an equivalent circuit diagram of the sensor,
[0023] FIG. 4, the essential elements of the sensor electronics
attached to the club shaft, and
[0024] FIG. 5, a simplified cross section of the housing of the
sensor electronics and the club shaft at an attachment
location.
[0025] A golf club is represented in FIG. 1, whose club head is
identified by 10, the shaft by 12 and the grip by 14. A sensor 18,
which will be explained in greater detail in what follows, is
fastened on the striking face 16 of the club head, and its actively
sensitive surface is identified by 20. Here, the directions of the
subsequently employed coordinates x, y and have also been drawn in.
Their common point of origin is located in the sweet spot 22 of the
striking face 16.
[0026] The sensor 18 is connected via a plug connection 24 and
signal lines 26, combined to form a cable, with sensor electronics,
identified as a whole by 30, having a measuring and computing
circuit and being mounted in a protective housing 28, which is
attached to the shaft 12 by means of an easily releasable fastening
mechanism 32, and is in contact via a radio module 34, preferably
Bluetooth, with a mobile evaluating device 36 in the nature of a
cell phone, smart phone or PDA, whose corresponding radio module is
identified by 38, a flat display screen with 40 and a keyboard by
42. If desired, a laptop can also be employed as the evaluating
device 36.
[0027] The x- and y-coordinates of the impact point of a golf ball
in relation to the sweet spot 22, determined by the measuring and
computing circuit 30 and registered accurately to a point by the
sensor 18, together with the coordinates of the impact points of
further ball strikes, are evaluated in the evaluating device 36
under program control and are graphically displayed.
[0028] The sensor 18 is of the structure represented in FIG. 2.
[0029] It consists of a support plate 48, which can be fastened by
means of a foil 46, adhesive on both sides, on the striking face
16, as well as a protective plate 50, arranged on the outside in
front of the support plate 48. For example, the support plate 48
can be made of fiberglass-reinforced epoxy resin (preferably FR4 or
FR5). The protective plate 50 can be made of a plastic material
(preferably polyester). Foils, commercially available under the
marks Tesa, Herma or Scotch, can be considered for the foil 46 with
adhesive on both sides, in which case the adhesive force is
preferably slightly greater on the side connected with the support
plate 48 than on the side to be connected with the striking face
16.
[0030] On their facing insides, the support plate 48 and the
protective plate 50 are each provided with an electrically
conductive layer 52, or respectively 54. These can be semiconductor
layers in accordance with U.S. Pat. No. 6,239,790 B1, which have a
defined linear resistance. Spacers 56 of sufficient size and
sufficiently distributed are arranged between the two electrically
conductive layers 52 and 54, which see to it that the conductive
layers 52, 54 only touch each other if a sufficient pressure is
regionally, or at points, exerted on the flexible protective plate
50, for example when struck by a golf ball. As indicated at 58, the
protective plate 50 is fixedly glued together with the support
plate 48 along the edge areas, but wherein at least one air inlet
and outlet opening, not represented, remains open and is designed
in the manner of a labyrinth seal, so that the sensor is protected
against dust and splashed water in accordance with IP54.
[0031] Also not represented are two printed strip conductors, which
extend along oppositely located edge areas of the support plate 48
and are electrically connected over their length with the
conductive layer 52. On its interior, the support plate 48 is
provided with two further printed strip conductors, which extend
along oppositely located edge areas at right angles in respect to
the first mentioned strip conductors and which, in the assembled
state, contact the electrically conductive layer 54 on the
protective plate 50 over their length.
Alternatively, the strip conductors which are electrically
connected with the conductive layer 54 can also be printed on the
protective plate 50. Each one of the four strip conductors is
connected with the measuring and computing circuit 30 via a signal
line, which continues in the cable 26.
[0032] If the flexible protective plate 50 is sufficiently far
indented at one location, so that the conductive layer 54 touches
the other conductive layer 52 on the support plate 48, it is
possible, following the application of a defined reference voltage
to the strip conductors connected to one of the two layers, to
measure a voltage between the strip conductors connected with the
respective other layer, which rises, or respectively falls,
proportionally to a change in the distance of the impact point from
the strip conductors charged with the reference voltage, so that,
following a calibration, it is also possible to determine the x-
and y-coordinates.
[0033] In connection with the computer touchpad of U.S. Pat. No.
6,239,790 B1, the distances of a pressure point from the strip
conductors, which are arranged at right angles in respect to each
other, are calculated on the basis of the length of time required
by the current for charging defined capacitors connected to the
strip conductors. An increased path of the current through one of
the conductive layers is equivalent to an increased resistance,
i.e. a reduced current strength, and therefore a longer period of
time needed for charging the respective capacitor.
[0034] In contrast thereto, for working with the novel sensor a
different, more rapid measuring method is provided because of the
shock-like loads. For this purpose, reference is made to the
equivalent circuit diagram in FIG. 3, in which the strip conductors
identified by Yl and Yr are arranged at the left, or respectively
right, edge of the conductive layer 52, for example, the strip
conductors identified by Zo and Zu are arranged at the upper, or
respectively lower edge of the conductive layer 54, the fixed
resistors assigned to the respective strip conductors are
identified by Ryr, Ryl, Rzo and Rzu, and the resistors in the
k.OMEGA.-range of the conductive layer 52, or respectively the
layer 54, respectively between the impact point and the four strip
conductors, are identified by Rya, Ryb, as well as Rza and Rzb.
[0035] Without contact between the two layers 52, 54 at the impact
point, the resistance between a strip conductor of the layer 52 and
a strip conductor of the layer 54 is infinite because of the
spacers 56. If a sufficiently large pressure is exerted on the
protective plate 50 at a point, the two layers 52, 54 constitute
the resistance network represented in FIG. 3. For the determination
of the coordinates of the impact point of a golf ball, a defined
reference voltage Vref is alternatingly applied during the strike
between Yl and Yr, as well as between Zo and Zu, and the voltage
drop is simultaneously measured with high-impedance at one end of
the other layer. As can be seen, the measured voltages between Zu
and Yr
Vz=Vref.times.(Rzb+Rzu)/(Rzo+Rza+Rzb+Rzu) and
respectively between Yl and Zo
Vy=Vref.times.(Rya+Ryl)/(Ryl+Rya+Ryb+Ryr)
are proportional to the position of the impact point in the Z- and
Y-directions on the sensor face. By measuring the voltages in case
of pressure on, for example four, registration markers 44, arranged
symmetrically around the zero point 22 of the coordinate system,
which have been imprinted on the support plate 50 at defined
spacings in the area of the active sensor face, it is possible to
determine the relationship between voltage and spacing, and the
sensor can be calibrated in this way, so that from the voltage
values a conversion into mm of the position relative to the zero
point 22 of the coordinate system placed on the sweet spot is
possible.
[0036] The measurements are continuously performed at a suitable
scanning frequency between 1 kH and 4 kH, preferably at 2 kH, in
order to be able to definitely determine the position of an impact
point in both coordinate directions during the length of the
pressure. Furthermore, the time of the striking of the golf ball
and the length of pressure can be determined in that valid
measurement values can be differentiated from 0 Volt by means of
the constant end resistors Ryl, Ryr, Rzo and Rzu. For the z-axis,
the voltages which can be measured when pressure is exerted are
between
Vref.times.(Rzo+Rza+Rzb)/(Rzo+Rza+Rzb+Rzu) Volt, and
Vref.times.Rzu/(Rzo+Rza+Rzb+Rzu) Volt, and for the y-axis
between
Vref.times.(Ryl+Rya+Ryb)/(Ryl+Rya+Ryb+Ryr) Volt, and
Vref.times.Ryr/(Ryl+Rya+Ryb+Ryr) Volt.
Scanning is performed at 8 bit to 12 bit, preferably at 10 bit.
[0037] In FIG. 4, the essential parts of the measuring and
computing circuit 30 are represented. They are attached to a board
60 in the housing 28 and are interconnected in the customary
manner.
[0038] Most important is a micro-computer, identified by 62, having
RAM, a FLASH memory, A/D converters, inputs and outputs (GPIOs) and
a serial interface, preferably UART and SPI. The micro-computer 62
controls the application of the reference voltage to the signal
lines, which are connected with the electrically conductive layers
52, 54, registers the voltages measured in the course of the
measuring process and the associated times, and calculates the
coordinates of the impact points. These are intermediately stored
and are passed on to the evaluating device 36 via the radio module
34 with an aerial, preferably a ceramic aerial 35. A battery 64 is
used for the electrical current supply, whose charging regulator is
represented at 66. Charging takes place through a jack 68,
preferably an USB jack of the type Mini-B, or a 2.5 mm jack bush.
The micro-computer 62 can also be reprogrammed via this jack.
[0039] A quick-fastening mechanism for the releasable fastening of
the housing 28 of the measuring and computing circuit 30 on the
shaft 12 of the golf club is represented in FIG. 5 which, in
accordance with FIG. 1, is preferably located on the side of the
shaft 12 opposite the club head 10, or on the side opposite the
striking face 16. As represented, on the side resting against the
shaft 12 the housing 28 is cut out in a channel-like manner with a
diameter slightly larger than the shaft diameter. A rubber insert
70 has been placed between the housing 28 and the shaft 12, which
can also be glued to the housing 28 and can aid in protecting the
housing against dust and splashing water in accordance with IP54.
The connection of the housing with the shaft 12 takes place by
means of a flexible plastic shackle or a clamping strip 72, for
example a textile strip, each of which can be rubberized on the
inside. The one end of the clamping strip 72 is fixed on a
deflection pin 74 connected with the housing 28. On the side of the
housing 28 located opposite the deflection pin, the clamping strip
placed around the shaft 12 is connected with a clamping or
arresting lever 76, which engages a cutout 78 of the housing 28 and
clamps the clamping strip 72 in the course of its closing movement.
It is understood that a multitude of other mechanisms for fastening
the housing 28 on the shaft 12 exists, for example hooks on at
least one side of the housing 28, into which the rubber clamping
strips, which have been passed around the opposite side of the
shaft 12, are hooked.
[0040] The evaluating device operates in the master mode in order
to receive, when required, the measurement data from several
measuring and computer circuits 30 which, for example, are each
transmitted via Bluetooth, or a suitable transmission protocol,
preferably SPP or HDI, to the evaluating device 30, to store them,
evaluate them and to display them. It is possible in this way for
two or four players, for example, to directly compare their
evaluated data with each other on a common curve diagram.
* * * * *
References