Swimmer's training apparatus with a visual display

A training apparatus with a visual display for a swimmer. In a first aspect of the invention, an impeller mounted in a module worn by a swimmer is driven by a forward motion of the swimmer. A pair of permanent magnets mounted on opposite vanes of the impeller act on a magnetic field type transducer to produce a pulsating voltage which varies directly in frequency with the speed of the swimmer. The output of the sensor is processed and transmitted to a visual display worn by the swimmer. Changes in the visual display enable the swimmer to identify the effect of changes in the swimmer's form and/or movement on his performance. In a second aspect of the invention, a revolving magnet produces a pulsating voltage in a coil of wire. The output of the coil is processed and transmitted to a visual display worn by the swimmer.

FIELD OF THE INVENTION 
This invention relates to training devices and more particularly to a 
training apparatus for a swimmer. 
BACKGROUND OF THE INVENTION 
Lap counters and timing devices are widely used for training swimmers. The 
devices are unable to detect the effects of small changes in performance. 
Consequently, the effects of small changes in a swimmer's technique are 
overlooked. In competitive swimming, winners and losers are often decided 
by as little as a small fraction of an arm length. Small changes in a 
swimmer's performance can result in either a gold medal or a last place 
finish. 
In my pending U.S. application Ser. No. 08/629,026, a training apparatus is 
disclosed which instantly informs a swimmer of the effects of changes in 
his form and/or movements on his performance. Not only is he able to 
instantly detect small changes in his performance, but also to improve his 
performance more quickly, because he can evaluate multiple changes in his 
technique during a single lap of a pool. 
In the referenced pending application, a module is mounted on a swimmer and 
generates audio signals that vary in frequency with the swimmer's speed. 
The audio signals are transmitted to an earphone worn by the swimmer to 
permit him to evaluate whether his performance has improved. 
SUMMARY OF THE INVENTION 
This invention is a development of the referenced U.S. patent application 
Ser. No. 08/629,026 which is incorporated herein by reference. A primary 
object of this invention is to employ visual signals in lieu of audible 
signals for improving a swimmer's performance. Another object is to 
provide a training apparatus which is substantially "service free". 
In keeping with the above objectives, a substantially "service free" module 
is attached to the waist of a swimmer which transmits visual signals to 
the swimmer that enable the swimmer to evaluate small changes in his form 
and/or movements. 
In a first aspect of the invention, an impeller is mounted in a battery 
powered module worn by a swimmer and is driven by a forward motion of the 
swimmer. The impeller revolves about an axis which is normal to the path 
of the swimmer and has a pair of permanent magnets mounted at the ends of 
opposite vanes of the impeller. The magnetic fields of the revolving 
magnets act on a magnetic field type transducer to produce a pulsating 
voltage signal which varies directly in frequency with the speed of the 
swimmer. 
The output of the magnetic field sensor is electronically processed and 
transmitted to a flashing visual display worn by the swimmer. Changes in 
the frequency of the flashing visual display inform the swimmer of whether 
changes in his form and/or movement have improved or otherwise altered his 
performance. A sensitivity control is provided to compensate for 
differences between beginning swimmers and accomplished swimmers. 
At a high level of the sensitivity control, changes in the frequency of the 
visual display are greater with small changes in the swimmer's speed. A 
water actuated switch is provided to activate the module when it is 
immersed in water and to de-activate the module when it is removed from 
the water. The water actuated switch extends the life of the battery by 
preventing the module from inadvertently being left operational when it is 
removed from the water. 
In a second aspect of the invention, a pulsating voltage is induced in a 
coil of wire by revolving magnets. The voltage which is induced in the 
coil is processed and transmitted to the visual display worn by the 
swimmer. A battery is not a necessity in the second aspect and is 
optional. 
Several types and patterns of visual displays are disclosed which apply to 
either aspect of the disclosed swimmer's training apparatus In one of the 
embodiments, an audio system is incorporated as an option for evaluating 
changes in a swimmer's performance. 
Further objects, benefits and features of the invention will become 
apparent from the ensuing detailed description and drawings which disclose 
the invention. The property in which exclusive rights are claimed is set 
forth in each of the numbered claims at the conclusion of the detailed 
description.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings wherein like numerals designate like and 
corresponding parts throughout the several views, in FIGS. 1-12, 
inclusive, a swimmer's training apparatus is illustrated which embodies 
the present invention. A distinguishing feature of the invention is that a 
visual display 46 informs a swimmer whether changes in his technique have 
improved or reduced his performance. The visual display 46 may be in 
various patterns and forms, hereinafter sometimes referred to as "the 
information", it not being my intention to limit the scope of my invention 
to a particular pattern or form. 
The invention can be generally understood by referring to FIGS. 1 through 
15, inclusive, taken in conjunction with the following description. A 
generally rectangular compact module 31 is attached to the underside of a 
swimmer 32 with a belt 33 that surrounds the swimmer's waist. The position 
of the module 31 is preferable because it provides a relatively 
unobstructed path for water to enter an aperture 34 in a lower housing 35 
of the module 31 when the swimmer 32 advances in the water. Moreover, it 
places the module 31 at a distance from turbulence due to the swinging 
arms and feet of the swimmer 32. 
When the swimmer 32 advances in the water, water enters the aperture 34 in 
the direction of arrow "A" and rotates an impeller 36 about an axis which 
is perpendicular to the path of the swimmer 32. At the entrance to the 
module 31, ahead of the impeller 36, are a series of straightening vanes 
37 for reducing turbulence which may be present in the water entering the 
module 31. 
A pair of permanent magnets 40 and 41 are mounted on end portions of 
opposite blades 39 of the impeller 36 and revolve with the impeller 36 
when the swimmer 32 moves through the water. One of the magnets 40 has an 
outward facing north pole and the other magnet 41 has an outward facing 
south pole. The revolving magnets 40 and 41 produce a pair of revolving 
magnetic fields which act on a sensor 42, such as a Hall effect or 
magneto-resistive magnetic field transducer. The sensor 42 is mounted in 
an upper housing 43. The effect of the magnets 40 and 41 on the sensor 42 
is a pulsating output signal whose frequency varies directly with the 
speed of the swimmer 32. As will be later understood in the present 
invention, a coil of wire 44 may also be used in lieu of a magnetic field 
sensor, to produce a pulsating signal. 
By way of example of a magnetic field sensor, one type of Hall sensor 42, 
commonly referred to as a Hall switch, has two output voltage states, 
namely, an "ON" ("high") state and an "OFF" ("low") state. Each time the 
outward facing north pole passes the sensor 42, the output goes low and 
remains low until the outward facing south pole passes the sensor 42, 
causing the output to go high. With a single pair of magnets 40 and 41, 
the sensor 42 produces one pulse during each rotation of the impeller 36. 
The number of pulses per each rotation can be increased by increasing the 
number of magnets on the impeller and/or providing multiple sensors. 
Since the rotational speed of the impeller 36 varies directly with the 
speed of the swimmer 32, changes in the frequency of the output signal of 
the sensor 42 are indicative of changes in the swimmer's speed. It will be 
understood from the referenced pending application Ser. No. 08/629,026, 
that a single output pulse can also be obtained with single ring and bar 
permanent magnets. 
The output of the sensor 42 is fed to a signal processing unit 45 wherein 
the signal is processed prior to being transmitted to a visual display 46 
worn by the swimmer 32. After processing, the signal is transmitted to the 
visual display 46 worn by the swimmer 32. The sensor 42 and signal 
processing unit 45 are comprised of linear and digital circuits and 
components which are known in the art. 
In the embodiment depicted in FIGS. 2-4, the visual display 46 is comprised 
of a flashing single light emitting diode (LED) 48 mounted on a lens 49 of 
a conventional pair of swimmer's goggles 50. The LED 46 is connected to 
the module 31 by a wire 51. It will be appreciated that the LED 48 may 
also be mounted on slender arms attached to such devices as a swimmer's 
cap. 
Increases in the swimmer's speed causes the LED 48 to flash at a higher 
frequency, informing the swimmer 32 his speed has increased. Conversely, a 
decreased frequency informs the swimmer 32 his speed has decreased. 
Changes in color can also be used to indicate changes in speed. An LED 
which changes in color with changes in voltage is manufactured by 
Electronics Limited, and called an MVI (see Tracton, K, Display Devices, 
Tab Books, 1977). The Electronics Limited MVI diode changes from red to 
orange to yellow to chartreuse to green with increasing voltage. For this 
type of LED, the output of the signal processing unit 45 is a voltage 
which varies in magnitude directly with the frequency of the output of the 
sensor 42. 
LED's are particularly well suited for the present invention because they 
are sealed units, low in cost, draw only small amounts of current, are 
resistant to shock, and turn "on" and "off" at great speeds with short 
rise and fall times. Moreover, because light emission is by means of PN 
junctions rather than incandescence, they have exceptionally long service 
lives of about 100,000 hours. A further benefit is that they are available 
in several colors. 
In lieu of the single LED 48, LED arrays may be used for informing the 
swimmer 32 of changes in his performance. In FIGS. 3 and 13 a linear LED 
array 52 of single color light emitting diodes 53 is shown mounted on a 
pair of goggles 54. The linear array 52 is a component of an embodiment 
which is depicted in block diagram form in FIG. 13. For this array 52, the 
output of the sensor 42 is processed in the signal processing unit 45 to 
sequentially illuminate LED's 53 at a frequency which varies directly with 
the swimmer's speed in a repeating pattern. 
In FIGS. 6 and 14 a linear array 55 of yellow 56, green 57 and red 58 light 
emitting diodes is shown mounted on a pair of goggles 59. The linear array 
55 is a component of an embodiment which is depicted in block diagram form 
in FIG. 14. For this array 55, the output of the sensor 42 is processed in 
the signal processing unit 45 to sequentially illuminate the yellow 56, 
green 57 and red 58 LED's at a frequency which varies directly with the 
swimmer's speed in a repeating pattern. 
A sensitivity control 60 is provided to compensate for differences between 
the speeds of beginning swimmers and experienced swimmers wherein the 
degrees of improvements will substantially vary. The control provides 
three levels of sensitivity, namely a low ("LO") level 61, a medium 
("MED") level 62, and a high (HI") level 63. At the high level 63, which 
is intended to be used by experienced swimmers, small changes in a 
swimmer's speed will produce greater changes in the visual display 46 than 
at the low level 61. A brightness control 64 is also provided to adjust 
the brightness of the visual display 46. 
Referring now to FIGS. 7 through 11, the upper housing 43 of the module 31 
is comprised of a top half 65 and a bottom half 66. Between the top half 
65 and the bottom half 66 is a gasket 67. At the sides of the top half 65 
are integral loop shaped brackets 68 which attach the belt 33 to the 
module 31. The belt 33 passes through the brackets 68 and over the top 
half 65. 
The earphone which is shown in FIGS. 1 and 8 is part of the optional audio 
mode which is shown in the block diagram of FIG. 15 wherein the audio mode 
is optional with a visual mode. The audio mode is more fully described in 
the referenced pending application Ser. No. 08/629,026. The embodiment of 
FIG. 15 also includes a mode switch 70 and a volume control 71. A 
frequency multiplier and amplifier for use in the audio mode are disclosed 
in the referenced pending application and are incorporated in the signal 
processing unit 45 of FIG. 15 by reference. 
Referring now to FIG. 11, inside of the module 31 is a circuit board 72 
which carries the components of the signal processing unit 45. Also inside 
the module 31 are a brightness control 64, a water actuated switch 74, and 
a pair of batteries 75. 
The water activated water switch 74 and its associated circuitry are shown 
in block diagram form in FIG. 20. The switch 74 is normally open and 
automatically closes when the module 31 is immersed in water. When the 
module 31 is removed from water it opens. When the module 31 is immersed 
in water, two exposed contacts 76 on the module 31 are shorted together by 
the water to activate an "On-Off" circuit. The switch 74 is connected to 
the batteries 75 and a circuit which remains active when the switch 74 is 
removed from the water and power is interrupted to the other circuits. 
When the training apparatus is not in use, the active circuit draws a 
negligible current, commonly referred to as "quiescent current" in a 
microamp range. When the module 31 is immersed in water and the contacts 
76 are shorted, a transistor 77 is turned on thereby energizing a relay 
coil 78. The relay's contacts 79 close, supplying power to the other 
circuits. 
Adjacent the water switch 74 on the bottom half 66 of the upper housing 43 
are a knob 80 for adjusting sensitivity and a knob 81 for adjusting the 
brightness of the visual display 46. 
Referring now to FIGS. 16 through 19, an embodiment is shown wherein a 
pulsating voltage is generated by a coil 82 in a rotating magnetic field 
of a single ring magnet 83 which is driven by a propeller 84. The ring 
magnet 83 is mounted on a common shaft 85 with the propeller 84. The 
propeller 84 is driven by the motion of the swimmer 32 and revolves about 
an axis which is aligned with the path of the swimmer 32. The magnetic 
field of the rotating ring magnet 83 induces a pulsating voltage during 
each revolution of the magnet 83. The pulsating output of the coil 82 is 
processed in a signal processing unit 45 and transmitted to a visual 
display 46 worn by the swimmer 32. 
The use of the battery for this embodiment is optional and will depend on 
the current requirements of the visual display. An optional battery 75 is 
shown in phantom. 
From the foregoing, it will be appreciated that my invention provides a 
swimmer's training apparatus having benefits heretofore unavailable. My 
invention not only provides a means for optimizing a swimmer's 
performance, but also a means for reducing the time for optimizing his 
performance. Moreover, the invention is easy to operate and is 
substantially "service free". 
Although only several embodiments have been illustrated and described, it 
is not my intention to limit my invention to these embodiments, since 
after having the benefit of this disclosure, obvious changes in material, 
shape, arrangement of components and substitution of components can be 
made by ordinary persons skilled in the art without departing from the 
spirit thereof.