Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF INVENTION
DRINKING FOUNTAIN FLOW CONTROL
FIELD OF THE INVENTION
This invention relates to water fountains. More particularly, this invention
relates
to drinking water fountains and to a means for controlling the dispensing of
water.
BACKGROUND OF THE INVENTION
It is known to provide a drinking water fountain equipped with a sensor to
commence dispensing a stream of drinking water when a user is within a
predetermined distance of the water outlet. U.S. Patent No. 5,033,508 to
Laverty, Jr. discloses such a system. U.S. Patent No. 7,430,998 to Perlsweig
et
al. discloses the use of a light beam, which when interrupted causes the
dispensing of water for consumption by animals. It is also known to
automatically
dispense water from an appliance, such as a refrigerator, when a glass or
other
container is inserted into a dispensing area.
Ideally, the flow from a drinking fountain is at a sufficiently high pressure
to
create a clean arc of water from which the user may drink. In some cases, the
pressure in the water fountain is too high with the result that the water is
ejected
beyond the basin or it sprays onto the user. Conversely, older public drinking
zo fountains often have an inadequate flow of water at the outlet such that a
person's mouth must touch or come close to touching the outlet in order to
drink
the water. The volume of water available in such cases also often frustrates
drinkers. Indeed, a drinker may be content to sip lightly from the edge of a
modest flow while others might wish for a higher volume directly into the
user's
mouth. Manual controls for fountains are usually not suitable for such fine
adjustments of the water flow.
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It is a further object of the invention to provide a drinking fountain that
provides a
stream of water at a distance that is convenient for drinking. It is a further
object
to accommodate a drinker's preference as to the rate of flow (volume per
second) of the water being dispensed or the distance at which the user prefers
to
drink.
These and other objects of the invention will be better understood by
reference to
the detailed description of the preferred embodiment which follows. Note that
the
objects referred to above are statements of what motivated the invention
rather
than promises and that not all of the objects are necessarily met by all
to embodiments of the invention described below or by the invention defined by
each of the claims.
SUMMARY OF THE INVENTION
According to the invention, there is provided a drinking water fountain with a
mechanism for varying the water pressure that is presented to the outlet of
the
fountain. A sensor detects the distance of a user's face from the outlet or
from
some other reference point as the user's face approaches the reference point
and the sensor communicates with a controller that regulates the water
pressure
as some function of that distance. For example, the pressure at which the
water
is dispensed may increase the closer the face gets to the reference point, it
may
vary with the speed at which the face approaches, or with the rate of change
of
speed of the user's face, i.e. its acceleration.
Preferably, the water pressure has a predetermined range of acceptable
dispensing pressures and the specific pressure within that range is determined
by some function of the distance of the user's face as sensed by the sensor.
The pressure is initially provided at a nominal non-zero starting pressure or
a
pressure at the low end of the predetermined range, and may increase at least
to
the point of producing an arch of water of a height predetermined to be
suitable
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for most drinkers when the user's face reaches the apex of the arch. The apex
of
such arch can be taken as the reference point for the distance of the user's
face.
For example, the pressure may increase in an inverse proportion to the
distance
of the user. Once the user has reached the stream of water and ceases to
approach further, the flow stabilizes. This allows the user to sip from the
stream
of water. However, if the rate of flow of the water is unsatisfactory to the
user,
he/she approaches closer (past the apex or closer to the outlet than the apex)
thereby increasing the pressure and the rate of flow and allowing a higher
volume of water per second.
In another embodiment, the function of distance may be the rate of change of
distance of the user's face from the outlet (or from some other reference
point).
If the user approaches the outlet more rapidly, the pressure at each distance
will
be greater (within a predetermined range). This allows the water to reach
farther
for a given distance of the user's face and enables users to drink at
different
distances, which may be of convenience for taller users.
In another embodiment, the function of distance may be the rate of change of
speed (acceleration) of the user's face toward the outlet or toward some other
reference point.
In one aspect, the invention is therefore a drinking water fountain comprising
a
water outlet, at least one distance sensor, and means for varying the water
pressure that is responsive to the output of the sensor to vary the water
pressure
as a function of the distance of a user's face as measured by the sensor. The
distance may be evaluated between the user's face and the outlet or between
the
user's face and another reference point, which may be a point in space
corresponding to the apex of a predetermined arc of water.
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In a more particular aspect, the function is an inverse proportion to the
distance.
In another more particular aspect, the function is the speed of the user's
face as
it approaches the outlet or the point in space corresponding to the apex. In
an
aspect, the means continues to increase the pressure as the user's face passes
the point in space, corresponding to when the user leans further into the
stream
of water.
In another more particular aspect, the function of distance is acceleration
toward
the outlet or other reference point, such that the means varies the water
pressure
as a function of the acceleration of the user's face.
In another aspect of the invention, the means is calibrated to cause the water
to
meet the user's face at a predetermined convenient height above the outlet.
The invention therefore provides a non-contract and intuitive means to adapt
and
adjust the water output to the distance of the user as the user approaches the
outlet, and that is responsive to the behavior of the user.
The foregoing was intended as a summary only and of only some of the aspects
of the invention. It was not intended to define the limits or requirements of
the
invention. Other aspects of the invention will be appreciated by reference to
the
detailed description of the preferred embodiments. Moreover, this summary
should be read as though the claims were incorporated herein for completeness.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described by reference to the detailed description of
the
preferred embodiment and to the drawings thereof in which:
Fig. 1 is a cross-sectional view of a drinking fountain according to the
preferred embodiment of the invention; and,
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Fig. 2 is a cross-section view of a drinking fountain according to an
embodiment of the invention with a vertical jet of water rather than an arc.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
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Fig. 1 illustrates a drinking fountain 10 according to the preferred
embodiment of
the invention.
Drinking fountain 10 includes a water outlet 12 arranged to project an arched
stream of water 14 at a given operating pressure.
Fountain 10 further comprises a distance sensor 16 capable of outputting a
io signal that corresponds to the distance of the user's face 18. The distance
sensor 16 is preferably located in close proximity to the outlet 12 so as to
effectively determine the distance of a user's face 18 from the outlet 12
while
avoiding undue interference from the stream of water or from the other
components of the fountain.
According to the preferred embodiment, the distance sensor 16 is an optical
triangulation range sensor capable of image capture and of producing outputs
at
a frequency of 200 Hz. During installation, the sensor 16 may be adjusted so
that its field of view avoids encompassing portions of the drinking fountain
or
alternatively, the sensor output might be calibrated to discount the presence
of
such features. In the illustrated embodiment, sensor 16 is mounted slightly
above and behind an apex point 20 of an arch of water of a predetermined
height
considered suitable for most users.
A plurality of sensors may also be used to determine more accurately the
distance of a user's face or to properly assess distances when a user
approaches from different directions or when a user leans downward into the
water stream with the objective of further increasing the flow of water. A
suitable
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calibration and configuration interface (not shown) is provided within the
drinking
fountain housing 22.
A controller 24 receives the output of the sensor 16 and controls a pressure
regulator 26 in water supply line 28.
The output of the sensor 16 is a signal that corresponds to the distance of an
object in the measuring range of the field of view of the sensor. The output
is fed
to the controller 24 which determines the actual distance that the signal
represents. The sensor 16 and the controller 24 are preferably configured to
cause the sensor 16 to determine distances at intervals of approximately 5 ms
once an object enters the field of view. That period allows for effective
tracking
of the distances, of the rate of change of distance and/or of the rate of
change of
speed (for the alternative embodiments described below) as a user's face
approaches the outlet 12 but other sensing periods may be considered suitable.
In an embodiment, the distance of the user's face is measured in relation to
the
outlet 12. As the user approaches the outlet, the controller 24 causes the arc
of
water to gradually increase in height in inverse proportion to the distance of
the
user's face 18 from the outlet 12. The system is calibrated to have the apex
20
of the arch meet the user's face 18 at a convenient, standard height A for the
average user (6 cm in the preferred embodiment). However, if the user's face
18
continues to approach the outlet 12 itself (i.e. the user leans further into
the
stream of water), the flow continues to increase so as to deliver more volume
to
the user.
A distance of 1.0 meter from the outlet 12 is preferred as a triggering
threshold
for the initial activation of the water flow. At that distance, the controller
24
causes the regulator 26 to initialize with a minimal, nominal flow of water
from the
outlet 12. A "nominal" flow can be taken to mean, for the purposes of this
application and the claims, an initialization flow at the low end of a
predetermined
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range of dispensing pressures. The pressure is then further adjusted within
that
range according to the proximity of the user's face. The system is calibrated
such that when the user's face 18 is at a position corresponding to the
standard
height A, the pressure will be such as to produce an arc of water that just
meets
the user.
The controller 24 causes the regulator 26 to increase the flow of water to the
outlet in direct inverse proportion to the distance of the user's face
(between 1.0
and 0.0 meter from the outlet), with a nominal flow at the triggering
threshold of
1.0 meter and a flow sufficient to reach apex A when the user's face is at 0.0
meter from the outlet 12.
As a user comes within the triggering range of a fountain, the flow is
initialized at
a nominal flow. As the user then approaches his or her face to the outlet 12,
the
flow increases in direct inverse proportion to the distance of the user's face
18
from outlet 12. The resulting effect is a smooth transition from an initial
flow and
culminating in a standard flow just as the user's face reaches the apex point
A (of
the standard flow). There is also the pleasing effect of being directly
responsive
to the user.
If the user prefers to sip lightly from the edge of the flow rather than from
its
apex, the user will stop short at which point the flow will be slightly less
than the
standard flow but the user will be able to drink from the downward edge of the
arch. Other users will prefer to drink directly from the apex and will lean in
until
the arc of water rises to meet the user at that point to deliver a moderate
volume
of water per second. When a user prefers to receive a greater volume of water,
the user leans further into the water (closer to the actual outlet) which is
detected
by the sensor 16 and by the controller 24 which then causes the pressure to
increase further to deliver a stronger flow of water to the user. The user
therefore controls the volume of water desired and the height of the arch.
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The invention therefore provides the ability to provide a stream of water that
is
responsive to the distance of the user to the outlet, allowing a weaker flow
for the
user that prefers to drink from the side of the arch, a standard flow for the
drinker
preferring a standard flow of water and a stronger flow for the thirstier
drinker. As
the thirstier drinker backs off from drinking deeply into the water stream,
the
stream decreases to avoid splashing the user's face.
In another embodiment, the distance of the user's face is measured in relation
to
a point in space P that corresponds to a predetermined convenient apex height
A
of the arc of water for the average user. The sensor(s) 16 and controller 24
determine the distance of the user's face 18 from point P. If the distance is
0.0
meter, the pressure is controlled to produce an arc of water corresponding to
the
predetermined standard pressure and apex height A. If the user leans downward
past point P (effectively a negative distance from point P), the controller 24
will
continue to increase the pressure to deliver a greater volume of water.
In a further alternative embodiment, the controller 24 is configured to
receive the
successive distance inputs from the sensor 16 and to determine the rate of
change of distance. The controller 24 then increases the relative flow of
water
from a baseline nominal flow according to the speed at which the user
approaches the outlet 12 or the apex point P as the case may be. As the speed
of approach increases, the rate of water flow at each distance increases as
compared to the water flow at the same distance in a slower approach.
According to this embodiment, the maximum pressure and apex may be adjusted
upward to accommodate the greater flows contemplated for a fast approaching
user. Thus a taller person might lean into the drinking fountain faster and
thereby generate a higher apex and a relatively stronger flow of water than a
more slowly approaching user.
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In yet another embodiment the function of distance is acceleration toward the
outlet or toward apex point A. When the user is within the activation range
(e.g.
1.0 meter), the flow is initialized at a nominal flow. As the user approaches,
the
controller interprets the successive sensor outputs to derive an acceleration
of
the user's face. A greater acceleration triggers a greater water pressure, but
constrained within the acceptable dispensing range of water pressures.
Various modifications to the embodiments and to the invention may be
contemplated. For example, rather than supplying an arc of water, the fountain
may generate a vertical stream of water as illustrated in Fig. 2. In such
case, the
operative direction of approach of the user to be evaluated may be chosen to
be
the vertical direction. The positioning and field of views of any sensors
would be
adjusted accordingly and may be directed upward from a suitable vantage point
toward the approach user's face. The system may be configured for a standard
apex height of the jet of water such that the pressure gradually increases
until the
user's face meets the apex of the stream at a convenient, standard apex
height.
As the user leans farther into the stream, the pressure increases to provide a
greater volume of water. As the user withdraws from the stream, the pressure
immediately decreases to avoid splashing the user's face.
It will be appreciated that various locations and configurations of a sensor
or of a
zo plurality of sensors may be used to achieve accurate readings of the
distance
and pose of a user's face, so as to discount possible sources of error such as
the
presence of the user's forehead, and interference by the stream of water and
the
fountain hardware itself.
Various operational parameters can further be determined for the system. For
example, the controller may be configured to deactivate the fountain entirely
if
the user overshoots the outlet by a predetermined amount. In the alternative
embodiment, an upper limit may be placed on the increase in pressure as a
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function of speed of the user. The system may be configured to allow the
sensor-based invention to be overridden by a manual control. Other variations
to
the described embodiments and their operational parameters may be
contemplated.
5 Indeed, in the foregoing specification, the invention has been described
with
reference to specific embodiments thereof.
However, they are merely
embodiments illustrative of the principles of the invention. The scope of the
invention is not to be limited by the preferred embodiments set forth in the
examples, but should be given the broadest interpretation consistent with the
io description as a whole. The specification and drawings are, accordingly,
to be
regarded in an illustrative rather than a restrictive sense.
