[0001] The invention relates to a swimming starting block comprising a push-off plate for
supporting at least feet of a swimmer during a start, as well as a sensor device which
is connected to the push-off plate and which serves to detect at least changes in
pressure on the push-off plate induced by the swimmer.
[0002] Such a swimming starting block is generally known and is used at swimming competitions
to detect the moment at which the feet of the swimmer leave the starting block. The
starting block comprises pressure-sensitive sensors. The sensors detect the moment
at which the swimmer leaves the starting block, and this information is used to detect
reaction times, push-off times and push- off delay time. It is a drawback of the known
device that it is relatively inaccurate.
[0003] It is an object of the present invention to provide a swimming starting block having
improved accuracy. A further object of the present invention is to provide a swimming
starting block which can be used by the swimmer, for example during training, to improve
his starting technique.
[0004] To achieve this, the invention provides a swimming starting block of the type mentioned
in the opening paragraph, wherein the sensor device comprises a substantially elongated
conductor for electromagnetic signals, which is connected with a first circumferential
side (circumferential part) to the push-off plate and with a second circumferential
side, situated substantially opposite the first circumferential side (circumferential
part), to a sensor-support plate arranged at a distance from the push-off plate and
extending substantially parallel thereto, wherein the push-off plate, in operation,
is movable with respect to the sensor-support plate, under the influence of pressure
changes induced by the swimmer, to induce a disturbance into electromagnetic signals
sent through the conductor, wherein the elongated conductor can be connected, at an
end thereof, to a signal source for transmitting the electromagnetic signals through
the conductor, and wherein the conductor can be connected, with a second end situated
opposite the first end, to a signal detector, wherein the signal detector is arranged
to detect disturbances in the electromagnetic signal. The signal may consist of electromagnetic
radiation in the visible spectrum, but also of signals with radiation of other wavelengths.
An above described conductor with signal source and signal detector is available,
for example, under the name of Lightspeed Optical Detection System, OSP.01.03, from
the firm of Lightspeed Systems, Asten, The Netherlands. The conductor may be a synthetic
resin optical cable through which light can be sent. Such a conductor is also described
in
NL 1024456, which publication is incorporated by reference. The push-off plate is movable relative
to the sensor support plate to induce, for example, a micro bend or micro stretch
into the conductor. A micro bend or micro stretch is a very small deformation which
leads to a noticeable disturbance of the signal sent through the conductor. When pressure
is exerted on the cable, mechanical kink points are responsible for deformations in
the cable. The signal detector is arranged to detect these disturbances in the electromagnetic
signal caused by the micro bend. The light changes caused by mechanical kink points,
when pressure is exerted, eventually lead to a noticeable change. In other words,
a relative movement of the push-off plate and the sensor support plate leads to a
noticeable deformation in the electromagnetic signal sent through the conductor. The
signal detector is further capable of detecting the degree of micro bending or micro
stretch. These deformations in the cable result in a change of the spectral distribution
of light, leading to a change in values. If these new values fall outside the set
detection limits, then a signal will be produced. The swimming starting block according
to the invention enables the push-off time, the reaction time and the push-off delay
time to be measured very accurately. It is additionally possible to determine the
push-off force, thus enabling the swimming starting block according to the invention
to be used also for improving the start technique of the swimmer.
[0005] The conductor is preferably direction-sensitive. The conductor such as, for example,
the one forming part of the above-described detection system OSP.01.03, is sensitive
to micro bends and or micro stretches in different directions, and the detector is
capable of detecting said micro bends or micro stretches in the different directions.
Consequently, the conductor is capable of distinguishing between relative changes
in pressure in different directions, and therefore can be used to calculate and determine
push-off force, push-off direction, time, reaction time, weight, etc. The swimming
starting block according to the present invention thus enables the swimmer to develop
an optimum start technique. In order to protect the conductor from external influences,
the sensor device preferably comprises a mat, which is provided between the push-off
plate and the sensor support plate. The conductor is arranged in the mat. The mat
is preferably a flexible mat such as, for example, a rubber mat. By virtue thereof,
micro bends in different directions are permitted.
[0006] The direction-sensitivity of the sensor device can be set by using a rigid construction
or mechanical boundary, so that micro bending or micro stretch can take place only
in one direction. The rigid construction should preferably counteract twisting of
the conductor. The rigid construction may comprise a pressure plate and a support
plate. The pressure plate is arranged on a first side of the conductor. The support
plate is arranged on the opposite side. The conductor is arranged such that micro
bends and stretch can take place only in the direction between the support plate and
the pressure plate. In this manner, the sensor device is rendered direction-sensitive.
By means of a number of sensor devices, each being direction-sensitive in a different
direction, the forces occurring can be divided, for example, into orthogonal components.
[0007] In order to further increase the accuracy of the swimming starting block, the sensor
device comprises a plurality of individual, elongated conductors for electromagnetic
signals, which are each connected to a signal source and a signal detector. By virtue
thereof, different parts of the push-off plate can be provided with different conductors,
enabling said different parts to be separately monitored. This enables a distinction
to be made in push-off time, push off force, push-off direction and the like between
a left foot and a right foot of the swimmer. It is also possible to make a distinction
between push-off force of a front part of the foot and a heel of the foot.
[0008] A further improvement of the accuracy is achieved when, in total, four individual,
elongated conductors are arranged according to a regular pattern between the sensor
support plate and the push-off plate. Said four elongated conductors can subdivide
the push-off plate into, for example, four surfaces, thus enabling a distinction to
be made, for example, between pressure influences of the front part of the foot and
the heel of the foot for both the left foot and the right foot.
[0009] In a further embodiment, the swimming starting block is provided with at least one
additional push-off plate and one additional sensor support plate, wherein the device
also comprises an additional elongated conductor, with additional signal source and
additional signal detector, arranged between the additional push-off plate and the
additional sensor support plate. The additional push-off plate can be arranged at
an angle with respect to the push-off plate. The additional push-off plate is, for
example, a comparatively frontmost part of the swimming starting block. This push-off
plate is used to detect and determine the push-off force and the push-off direction,
etc, of the hands of the swimmer. A subdivision into different surfaces, as described
hereinabove, is conceivable of course.
[0010] A further improvement of the accuracy is achieved when the swimming starting block
comprises a support block on which the sensor support plate is provided, said support
block being manufactured substantially from a composite material. The support block
provides the swimming starting block with the necessary height. By manufacturing the
support block from a composite material, a comparatively rigid support block is achieved,
which adds to the accuracy of the conductors. In addition, the composite material
is comparatively insensitive to the influences of the water-rich environment and possible
chlorine vapours.
[0011] The swimming starting block is preferably provided with a display screen for displaying
images, such as images giving information. The display screen can be used, for example,
to show video recordings of an element of swimming. For example, the swimmer can watch
his latest start and analyse it together with his coach. Additionally, or alternatively,
the various information acquired by the sensor device and/or specific information
can be displayed on the display screen. Thus, the swimmer immediately gets feedback
on his start, thereby better enabling the swimmer to improve his start procedure during
a training session. Additionally, the display screen can be used to display advertisements,
for example during races.
[0012] It is also conceivable that a number of display screens are provided on the swimming
starting block. These display screens can be arranged in different positions, such
that the information can be viewed from different directions. It is also conceivable
that a display device is connected to the sensor device, but not to the starting block
itself, for example because the display screen is arranged at a distance from the
starting block.
[0013] The invention will now be explained with reference to some figures. In the figures:
Figure 1 is a perspective view of a swimming starting block according to the present
invention;
Figure 2 is a sectional view, in perspective, of a swimming starting block according
to the present invention;
Figures 3A and 3B show diagrammatically, in outline, embodiments of the sensor device
and the starting block.
[0014] Figure 1 is a perspective view of a swimming starting block 1 according to an embodiment
of the present invention. The swimming starting block comprises a frame 48. On an
upper side of the frame 48, there is provided a push-off platform 5. The swimming
starting block 1 comprises two push of plates 6, 26 arranged on the upper side to
support at least feet of a swimmer during a start. The frontmost push-off plate 6
is intended for the front part of the foot, the rearmost push-off plate is intended
to support the heel of the foot. In a certain start position, the frontmost push-off
plate 6 may be intended for the frontmost foot, and the rearmost push-off plate 26
may be intended for the rearmost foot. A front side of the frame 48 is provided with
a handgrab for starts in the water. A housing 30 for, for example, a processing unit
of the sensor device, or other parts thereof, such as a signal source and/ or signal
detector, is connected to the frame 48. In addition, a display screen 9 is provided
in between the push-off platform 5 and the handgrab 2. Information can be displayed
on the display screen 9, as will be explained hereinbelow.
[0015] Figure 2 shows the swimming starting block 1 of figure 1 in greater detail. Underneath
push-off plate 6, there is arranged a sensor device, which is not shown in greater
detail, for detecting at least pressure changes on the push-off plate 6, 26 induced
by the swimmer. The sensor device comprises a substantially elongated conductor 4,
4', 24 for electromagnetic signals, which conductor is connected with a first circumferential
side (or part of the circumference) to the push-off plate 6, 26. The conductor is
connected with a second circumferential side (or part of the circumference), opposite
the first circumferential side, to a sensor support plate 7, 27 arranged at a distance
from the push-off plate. The sensor support plate extends substantially parallel to
the push-off plate. The conductor 4, 24' is provided in an elastic, flexible layer
of a material such as, for example, a rubber mat. For this purpose, apertures are
provided in the mat, through which apertures the conductor is passed. The conductor
can describe a zigzag-like pattern through the mat. The push-off plate 6, 26 is movable
relative to the sensor support plate 7, 27 to induce a micro bend or micro stretch
in the conductor 4, 24'. The movement may comprise a component in the normal of the
plane formed by the push-off plate 6, 26. The elongated conductor can be connected,
at an and thereof, to a signal source, not shown here, to transmit electromagnetic
signals through the conductor. The conductor can be connected, with a second end situated
opposite the first end, to a signal detector, which is not shown here. Said signal
detector is arranged to detect disturbances in the electromagnetic signal caused by
micro bending, as already described hereinabove.
[0016] Figures 1 and 2 show that the swimming starting block 1 is provided with, in total,
three push-off surfaces 6, 16, 26, each having associated conductors 4, 14, 24 and
sensor support surfaces 7, 17, 27. Each conductor is provided with a signal source
of its own and a signal detector of its own, but combined embodiments are also conceivable.
An additional push-off surface 16 is provided on the front side of the starting block
1. This push-off surface is also provided with a conductor 14 in a mat 13, and a sensor
support surface 17 situated at a distance from the push-off surface 16. By virtue
thereof, it is possible to determine also push-off times etc, and push-off forces
of hands of the swimmer. It is also possible to provide a plurality of conductors
underneath each push-off surface, such that each push-off surface is pressure-sensitive
in several parts. For this purpose, preferably use is made of a regular pattern.
[0017] In order to further improve the rigidity of the starting block and hence the accuracy
thereof, the swimming starting block can be manufactured substantially of a composite
material.
[0018] Figure 1 and figure 2 also show that the swimming starting block is provided with
a display device 9. Said display device 9 enables images to be shown. The display
device 9 may be connected to the sensor device, such that also information acquired
by means of the sensor device can be shown on the display screen 9.
[0019] Figures 3a and 3b diagrammatically show embodiments of the swimming starting block
101, 201 comprising the sensor device 102, 202, in which, in particular, the configuration
of the sensor device is elucidated.
[0020] Figure 3A shows an embodiment comprising a signal source 111 for transmitting the
electromagnetic signals through a conductor 104. The conductor is connected with a
first end to the signal source 111. The conductor 104 is connected with the other
end to a signal detector 113. By virtue thereof, disturbances in the electromagnetic
signal can be detected. The signal detector is connected to a processing unit 115,
such that the signal can be converted or processed. In the embodiment shown, the processing
unit is further connected to a display device 109, which, as described hereinabove,
may be connected to the swimming starting block 101. The swimming starting block 101
is diagrammatically shown. It comprises, inter alia, the pushoff plate 106 to which
the conductor 104 of the sensor device is connected, as has been described in greater
detail with reference to figure 2. The push-off action from the push-off plate 106
will cause a disturbance in the electric signal, which can be measured and determined
by the signal detector 113. By means of the processing unit, the signal can be converted
or recalculated into useful data, such as, for example, push-off force, start time,
etc.
[0021] Figure 3B shows an alternative embodiment in which the swimming starting block 201
is provided with two individual push-off plate portions 206a and 206b. An individual
conductor 204a and 204b extends through each push-off plate portion 206a and 206b,
respectively. The conductors are each connected to a signal source 211. A number of
signal sources may be provided. The conductors 206a and 206b are additionally each
connected to an associated signal detector 213a and 213b, respectively. Said signal
detectors are connected to a signal processing unit 215. By means of this embodiment,
data of two different parts 206a and 206b of the starting block 201 can be determined.
By virtue thereof, the push-off force, reaction time etc, for the various parts can
be determined, thus enabling an even more accurate result to be achieved. Of course,
a plurality of conductors may be arranged in the starting block 201. In addition,
it is conceivable that additional signal sources 211 and/or additional signal detectors
213 and/or additional processing units 215 are present. In addition, a display screen
may also have been provided.
[0022] The figures shown and the description given above relate only to a few embodiments
of the present invention. However, it will be obvious to those skilled in the art
that many variants, whether obvious or not, are possible within the protective scope
of the present invention as defined by the appended claims.
1. A swimming starting block comprising a push-off plate for supporting at least feet
of a swimmer during a start, as well as a sensor device which is connected to the
push-off plate and which serves to detect at least changes in pressure on the push-off
plate induced by the swimmer, wherein the sensor device comprises a substantially
elongated conductor for electromagnetic signals, which is connected with a first circumferential
side to the push-off plate and with a second circumferential side, situated substantially
opposite the first circumferential side, to a sensor-support plate arranged at a distance
from the push-off plate and extending substantially parallel thereto, wherein the
push-off plate, in operation, is movable with respect to the sensor-support plate,
under the influence of pressure changes induced by the swimmer, to induce a disturbance
into electromagnetic signals sent through the conductor, wherein the elongated conductor
can be connected, at an and thereof, to a signal source for transmitting the electromagnetic
signals through the conductor, and wherein the conductor can be connected, with a
second end situated opposite the first end, to a signal detector, wherein the signal
detector is arranged to detect disturbances in the electromagnetic signal.
2. A swimming starting block according to claim 1, wherein the conductor is direction-sensitive.
3. A swimming starting block according to claim 1 or 2, wherein the sensor device is
provided in a mat, preferably a rubber mat, which is arranged between the push-off
plate and the sensor support plate.
4. A swimming starting block according to one or more of the preceding claims, wherein
the sensor device comprises a plurality of individual, elongated conductors for electromagnetic
signals, which are each connected to a signal source and a signal detector.
5. A swimming starting block according to claim 4, comprising a number, preferably four,
individual, elongated conductors, which are provided between the sensor support plate
and the push-off plate according to a regular pattern.
6. A swimming starting block according to one or more of the preceding claims, comprising
at least one additional push-off plate and one additional sensor support plate, wherein
the device also comprises an additional elongated conductor, with additional signal
source and additional signal detector, arranged between the additional push-off plate
and the additional sensor support plate.
7. A swimming starting block according to one or more of the preceding claims, comprising
a support block on which the sensor support plate is provided, said support block
being manufactured substantially from a composite material.
8. A swimming starting block according to one or more of the preceding claims, comprising
a display device which is connected to the swimming starting block.
9. A swimming starting block according to claim 8, wherein the display device is connected
to the signal detector.