U.S. patent application number 17/324272 was filed with the patent office on 2021-09-02 for electronic showerhead device.
This patent application is currently assigned to OASENSE. The applicant listed for this patent is OASENSE. Invention is credited to RAVI BILLA, KUAN-TEH LI, NATALIE ROWAN, EVAN SCHNEIDER, CHIH-WEI TANG.
Application Number | 20210270019 17/324272 |
Document ID | / |
Family ID | 1000005614084 |
Filed Date | 2021-09-02 |
United States Patent
Application |
20210270019 |
Kind Code |
A1 |
LI; KUAN-TEH ; et
al. |
September 2, 2021 |
ELECTRONIC SHOWERHEAD DEVICE
Abstract
An electronic showerhead device for automatically controlling
water flow includes a body configured to be connected to a main
water channel via a main water valve, a presence detector located
within the body, and a first water channel providing a primary
water stream exiting the body. The primary water stream remains off
when the main water valve is turned on. Subsequent interruption of
the presence interrogation beam area by a person or an object turns
on the first water channel. The presence detector includes an
infra-red (IR) proximity sensor and a visible light sensor
(VLS).
Inventors: |
LI; KUAN-TEH; (Fremont,
CA) ; TANG; CHIH-WEI; (Mountain View, CA) ;
SCHNEIDER; EVAN; (Piedmont, CA) ; BILLA; RAVI;
(Mountain View, CA) ; ROWAN; NATALIE; (SAN JOSE,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
OASENSE |
Mountain View |
CA |
US |
|
|
Assignee: |
OASENSE
Mountain View
CA
|
Family ID: |
1000005614084 |
Appl. No.: |
17/324272 |
Filed: |
May 19, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/US2019/062914 |
Nov 25, 2019 |
|
|
|
17324272 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B05B 1/18 20130101; B05B
1/3026 20130101; E03C 1/057 20130101; B05B 12/122 20130101 |
International
Class: |
E03C 1/05 20060101
E03C001/05; B05B 1/30 20060101 B05B001/30; B05B 1/18 20060101
B05B001/18; B05B 12/12 20060101 B05B012/12 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 25, 2019 |
US |
PCT/US2019/062914 |
Claims
1. An electronic showerhead device for automatically controlling
water flow comprising: a body configured to be connected to a main
water channel via a main water valve; a presence detector located
within the body; a first water channel providing a primary water
stream exiting the body, wherein the first water channel is
connected to the main water channel, and wherein the primary water
stream remains off when the main water valve is turned on; wherein
subsequent interruption of a presence interrogation beam area by a
person or an object turns on the primary water stream; and wherein
the presence detector comprises an infra-red (IR) proximity sensor
and a visible light sensor (VLS).
2. The electronic showerhead device of claim 1, wherein the IR
proximity sensor comprises at least one IR emitter and at least one
IR receiver and wherein the IR emitter emits a conically shaped IR
presence interrogation light beam and the IR receiver detects IR
light reflected by a person or an object interrupting the IR light
beam and generates an IR receiver signal, and wherein presence of a
person or an object is determined as a result of a variation of the
IR receiver signal.
3. The electronic showerhead device of claim 2, wherein the visible
light sensor detects ambient visible light and generates a VLS
signal and wherein presence of a person or an object is determined
as a result of a variation of the VLS signal.
4. The electronic showerhead device of claim 3, further comprising
a computing processing unit (CPU) and an application comprising
computer executable instructions configured to receive and compare
the IR receiver signal and the VLS signal in order to determine
presence of a person or an object within the presence interrogation
beam area with high accuracy and reduced false negatives.
5. The electronic showerhead device of claim 2, wherein the IR
emitter is separated by the IR receiver by a distance of at least
1.5 cm.
6. The electronic showerhead device of claim 2, wherein the IR
proximity sensor and the VLS sensor are integrated in a sensor
housing comprising light absorbing material.
7. The electronic showerhead device of claim 6, wherein the sensor
housing comprises a cover transparent to visible light.
8. The electronic showerhead device of claim 1, further comprising
an electronically controlled valve and wherein the electronically
controlled valve is in-line with the first water channel and is
activated by the presence detector.
9. The electronic showerhead device of claim 1, further comprising
a second water channel providing a secondary water stream exiting
the body, wherein the second water channel is connected to the main
water channel and wherein turning on the main water valve turns on
only the secondary water stream, while the primary water stream
remains off.
10. The electronic showerhead device of claim 1, wherein the
conically shaped IR presence interrogation beam comprises a cone
angle in the range of 10 degrees to 45 degrees.
11. A water delivering device for automatically controlling water
flow comprising: a main body configured to be connected to a main
water channel via a main water valve; a presence detector located
within the main body; a first water channel providing a primary
water stream exiting the main body, wherein the first water channel
is connected to the main water channel, and wherein the primary
water stream remains off when the main water valve is turned on;
wherein subsequent interruption of a presence interrogation beam
area by a person or an object turns on the primary water stream;
and wherein the presence detector comprises an infra-red (IR)
proximity sensor and a visible light sensor (VLS).
12. A method for automatically controlling water flow in an
electronic showerhead device comprising: providing a body
configured to be connected to a main water channel via a main water
valve; providing a presence detector located within the body;
providing a first water channel providing a primary water stream
exiting the body, wherein the first water channel is connected to
the main water channel, and wherein the primary water stream
remains off when the main water valve is turned on; subsequently
interrupting a presence interrogation beam area by a person or an
object turns on the primary water stream; and wherein the presence
detector comprises an infra-red (IR) proximity sensor and a visible
light sensor (VLS).
13. The method of claim 12, wherein the IR proximity sensor
comprises at least one IR emitter and at least one IR receiver and
wherein the IR emitter emits a conically shaped IR presence
interrogation light beam and the IR receiver detects IR light
reflected by a person or an object interrupting the IR light beam
and generates an IR receiver signal, and wherein presence of a
person or an object is determined as a result of a variation of the
IR receiver signal.
14. The method of claim 13, wherein the visible light sensor
detects ambient visible light and generates a VLS signal and
wherein presence of a person or an object is determined as a result
of a reduction of the VLS signal.
15. The method of claim 14, further comprising providing a
computing processing unit (CPU) and an application comprising
computer executable instructions configured to receive and compare
the IR receiver signal and the VLS signal in order to determine
presence of a person or an object within the presence interrogation
beam area with high accuracy and reduced false negatives.
16. The method of claim 13, wherein the IR emitter is separated by
the IR receiver by a distance of at least 1.5 cm.
17. The method of claim 13, wherein the IR proximity sensor and the
VLS sensor are integrated in a sensor housing comprising light
absorbing material.
18. The method of claim 17, wherein the sensor housing comprises a
cover transparent to visible light.
19. The method of claim 12, further comprising providing an
electronically controlled valve and wherein the electronically
controlled valve is in-line with the first water channel and is
activated by the presence detector.
20. The method of claim 12, further comprising providing a second
water channel providing a secondary water stream exiting the body,
wherein the second water channel is connected to the main water
channel and wherein turning on the main water valve turns on only
the secondary water stream, while the primary water stream remains
off.
21. The method of claim 13, wherein the conically shaped IR
presence interrogation beam comprises a cone angle in the range of
10 degrees to 45 degrees.
22. A method for automatically controlling water flow in a water
delivering device comprising: providing a main body configured to
be connected to a main water channel via a main water valve;
providing a presence detector; providing a first water channel
providing a primary water stream exiting the main body, wherein the
first water channel is connected to the main water channel, and
wherein the primary water stream remains off when the main water
valve is turned on; subsequently interrupting a presence
interrogation beam area by a person or an object turns on the
primary water stream; and wherein the presence detector comprises a
combination of an infra-red (IR) proximity sensor and a visible
light sensor (VLS).
Description
CROSS REFERENCE TO RELATED CO-PENDING APPLICATIONS
[0001] This application is a continuation-in-part and claims the
benefit of PCT application Serial No. PCT/US2019/062914 filed on
Nov. 25, 2019 and entitled ELECTRONIC SHOWERHEAD DEVICE, the
contents of which are expressly incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an electronic showerhead
device and a method for automatically controlling water flow in an
electronic showerhead device and in particular to an electronic
showerhead device that includes an integrated power source and a
sensor for automatically regulating the water flow.
BACKGROUND OF THE INVENTION
[0003] Automatic flow control for a showerhead usually involves
detection of a user by a presence detector followed by activation
of a valve that controls the water flow by the presence detector.
The presence detector may be located near a faucet handle of a
shower or within the showerhead. Most of the prior art electronic
showerheads with automatic flow control require external electrical
power and sensor placement by qualified technicians, which makes
them difficult to install and expensive for retro-fitting existing
showerheads.
[0004] Furthermore, the location of the presence detector is
critical in order to avoid self-triggering of the showerhead or
getting the showerhead valve locked in the ON position. Also, the
presence detector is sensitive to the distance and the angle
between the showerhead and the user and their performance is
affected by the height and perimeter of the user.
[0005] Accordingly, there is a need for a water saving showerhead
device that reliably and consistently turns the water automatically
on when a user enters the sensing area and turns the water
automatically off when the user is not in the sensing area for
users with different heights and perimeters. There is also a need
for an electronic showerhead that does not present the problems of
self-triggering or locking the showerhead valve in the ON or OFF
positions. There is also a need for an electronic showerhead that
allows for a user to retrofit a conventional showerhead and attach
the electronic showerhead without the need of special tools,
special plumbing or electrical connections or an electrician or a
plumber.
SUMMARY OF THE INVENTION
[0006] In general, in one aspect, the invention features an
electronic showerhead device for automatically controlling water
flow including a body configured to be connected to a main water
channel via a main water valve, a presence detector located within
the body, and a first water channel providing a primary water
stream exiting the body. The primary water stream remains off when
the main water valve is turned on. Subsequent interruption of the
presence interrogation beam area by a person or an object turns on
the first water channel. The presence detector includes an
infra-red (IR) proximity sensor and a visible light sensor
(VLS).
[0007] Implementations of this aspect of the invention include one
or more of the following. The IR proximity sensor includes at least
one IR emitter and at least one IR receiver. The IR emitter emits
at least one conically shaped IR presence interrogation light beam
and the IR receiver detects IR light reflected by a person or an
object interrupting the IR light beam and generates an IR receiver
signal. Presence of a person or an object is determined as a result
of a variation of the IR receiver signal. The visible light sensor
detects ambient visible light. Presence of a person or an object is
determined as a result of a variation of the detected visible
light. The electronic showerhead device further includes a
computing processing unit (CPU) and an application comprising
computer executable instructions configured to receive and compare
the IR receiver signal and the VLS signal in order to determine
presence of a person or an object within the presence interrogation
beam area with high accuracy and reduced false negatives. The IR
emitter is separated by the IR receiver by a distance of at least
1.5 cm. The IR proximity sensor and the VLS sensor are integrated
in a sensor housing comprising light absorbing material. The sensor
housing comprises a cover transparent to visible light. The
electronic showerhead device further includes an electronically
controlled valve and the electronically controlled valve is in-line
with the first water channel and is activated by the presence
detector. The electronic showerhead device further includes a
second water channel providing a secondary water stream exiting the
body, and the second water channel is connected to the main water
channel. Turning on the main water valve turns on only the
secondary water stream, while the primary water stream remains off.
The conically shaped IR presence interrogation beam comprises a
cone angle in the range of 10 degrees to 45 degrees.
[0008] In general, in another aspect, the invention features a
water delivering device for automatically controlling water flow
including a main body configured to be connected to a main water
channel via a main water valve, a presence detector located within
the main body, and a first water channel providing a primary water
stream exiting the main body. The first water channel is connected
to the main water channel, and the primary water stream remains off
when the main water valve is turned on. Subsequent interruption of
a presence interrogation beam area by a person or an object turns
on the primary water stream. The presence detector comprises an
infra-red (IR) proximity sensor and a visible light sensor
(VLS).
[0009] In general, in another aspect, the invention features a
method for automatically controlling water flow in an electronic
showerhead device including providing a body configured to be
connected to a main water channel via a main water valve. Next,
providing a presence detector located within the body. Next,
providing a first water channel providing a primary water stream
exiting the body. The first water channel is connected to the main
water channel, and the primary water stream remains off when the
main water valve is turned on. Subsequently interrupting a presence
interrogation beam area by a person or an object turns on the
primary water stream. The presence detector includes an infra-red
(IR) proximity sensor and a visible light sensor (VLS).
[0010] The details of one or more embodiments of the invention are
set forth in the accompanying drawings and description below. Other
features, objects and advantages of the invention will be apparent
from the following description of the preferred embodiments, the
drawings and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 depicts an electronic showerhead device of this
invention;
[0012] FIG. 2 is a perspective view of the electronic showerhead
device of FIG. 1;
[0013] FIG. 3 is a side view of the electronic showerhead device of
FIG. 2;
[0014] FIG. 4 is a top view of the electronic showerhead device of
FIG. 2;
[0015] FIG. 5 is a bottom view of the electronic showerhead device
of FIG. 2;
[0016] FIG. 6 is a transparent side view of the electronic
showerhead device of FIG. 2;
[0017] FIG. 7 is an exploded front view of the electronic
showerhead device of FIG. 2;
[0018] FIG. 8 is a perspective view of the solenoid of FIG. 7;
[0019] FIG. 9 is a perspective view of the battery pack of FIG.
7;
[0020] FIG. 10A is a bottom view of the bottom component of FIG.
7;
[0021] FIG. 10B is a top view of the bottom component of FIG.
7;
[0022] FIG. 11A is a top view of the top component of FIG. 7;
[0023] FIG. 11B is a bottom view of the top component of FIG.
7;
[0024] FIG. 12 is a perspective view of the sensor of FIG. 7;
[0025] FIG. 13 is a schematic side view of the operating showerhead
device of FIG. 1;
[0026] FIG. 14 is a perspective view of another embodiment of the
showerhead device;
[0027] FIG. 15 is an exploded view of the embodiment of the
showerhead device of FIG. 14;
[0028] FIG. 16 is bottom view of the embodiment of the showerhead
device of FIG. 14;
[0029] FIG. 17 is a top view of the embodiment of the showerhead
device of FIG. 14;
[0030] FIG. 18 is a side view of the embodiment of the showerhead
device of FIG. 14;
[0031] FIG. 19-FIG. 23 depict schematic diagrams of the operation
steps of the showerhead device of FIG. 14;
[0032] FIG. 24 depicts a block diagram of the temperature sensor
control system of the showerhead device of FIG. 14;
[0033] FIG. 25-FIG. 27 depict schematic diagrams of the main water
flow and the secondary water flow (signal stream) of the showerhead
device of FIG. 14;
[0034] FIG. 28 depicts a block diagram of the generator and the
energy storage system of the showerhead device of FIG. 14;
[0035] FIG. 29 depicts a block diagram of the electronics system
diagram of the showerhead device of FIG. 14;
[0036] FIG. 30 depicts a logic diagram of the ON/OFF valve, sensors
and user positions of the showerhead device of FIG. 14;
[0037] FIG. 31 depicts another embodiment of an electronic
showerhead device of this invention;
[0038] FIG. 32 is an exploded view of the electronic showerhead
device of FIG. 31;
[0039] FIG. 33 is a schematic diagram of a prior art proximity
sensor;
[0040] FIG. 34 is a schematic diagram of an improved proximity
sensor used in the showerhead device of FIG. 31;
[0041] FIG. 35 is an enlarged view of area A in the showerhead
device of FIG. 31 and depicts the components of the proximity
sensor;
[0042] FIG. 36 depicts a schematic diagram of the operation of the
VLS sensor;
[0043] FIG. 37 depicts the IR sensor signal and the VLS signal;
[0044] FIG. 38 depicts the IR sensor signal and the VLS signal for
a person with dark hair;
[0045] FIG. 39 depicts the use of the combination of the IR sensor
signal and the VLS signal to determine the presence of a person
with dark hair;
[0046] FIG. 40 depicts the algorithmic logic of using the
combination of the IR sensor signal and the VLS signal to determine
the presence of a person within the presence interrogation area and
to turn on and off the water;
[0047] FIG. 41 is a schematic diagram of the housing of the
improved proximity sensor used in the showerhead device of FIG.
31;
[0048] FIG. 42 is a front cross-sectional view of the showerhead
device of FIG. 31;
[0049] FIG. 43 is another cross-sectional view of the showerhead
device of FIG. 31;
[0050] FIG. 44 is another cross-sectional view of the showerhead
device of FIG. 31;
[0051] FIG. 45 is a cross-sectional view of the in-line generator
of the showerhead device of FIG. 31;
[0052] FIG. 46 is a cross-sectional view of the space for the
in-line generator of the showerhead device of FIG. 31;
[0053] FIG. 47 is a perspective view of the bottom surface of the
showerhead device of FIG. 31;
[0054] FIG. 48 is a front view of the bottom surface of the
showerhead device of FIG. 31;
[0055] FIG. 49A is a top perspective view of the generator cap;
[0056] FIG. 49B is a bottom perspective view of the generator
cap;
[0057] FIG. 49C is a cross-sectional view of the generator cap;
[0058] FIG. 50A is a front perspective view of the generator;
[0059] FIG. 50B is a top perspective view of the generator;
[0060] FIG. 50C is a cross-sectional view of the generator;
[0061] FIG. 51A is a front perspective view of the midframe;
[0062] FIG. 51B is a top view of the midframe;
[0063] FIG. 51C is a cross-sectional view of the midframe; and
[0064] FIG. 51D is a bottom view of the midframe.
DETAILED DESCRIPTION OF THE INVENTION
[0065] The present invention provides an electronic showerhead
device that includes an integrated power source and a sensor for
automatically regulating the water flow.
[0066] Referring to FIG. 1, electronic showerhead device 100
according to this invention includes a hollow dome-shaped top cover
102 and a two-component bottom portion 101. Bottom portion 101
includes a top component 104 and a bottom component 106. The
showerhead device is attached to an inlet water pipe 92 at the top.
The bottom surface 106a of bottom component 106 includes an area A
with openings 110 arranged so that they form a spray nozzle. In
operation, water 90 enters the showerhead 100 through the inlet
pipe 92 and exits through openings 110 and forms a parabolic water
stream 180, as shown in FIG. 13. Bottom surface 106a of the bottom
component 106 also includes a sensor 108 protruding from an opening
in area B of the bottom surface adjacent to area A. Sensor 108 is
an Infrared (IR) sensor that emits a conical shaped IR beam 150
that extends above and adjacent to the water stream 180. In some
embodiments, the conical shaped IR beam 150 is tangential to the
water stream 180. Sensor 108 looks for reflected beam signals, and
turns "ON" when a certain threshold of reflected IR energy is met
or exceeded. Sensor 108 controls an ON/OFF valve for the water
stream, as will be described below. In other embodiments, sensor
108 is a radar sensor or a capacitor sensor. Bottom surface 106a of
the bottom component 106 also includes a power ON/OFF switch 112
that controls the flow of electrical power to the showerhead device
100, as shown in FIG. 2.
[0067] Referring to FIG. 6 and FIG. 7, the electronic showerhead
device 100 also includes an electronically controlled valve 120 and
a battery pack 130 that are located within the hollow dome-shaped
top cover 102 above the two-component bottom portion 101. In one
example, the electronically controlled valve is an electromagnetic
solenoid 120 that is in-line with the inlet water pipe 92 and is
configured to receive an electrical signal from the IR sensor 108
and to turn ON or OFF the flow of water 90 in the water stream 180.
Electromagnetic solenoid 120 is a "latching" solenoid that utilizes
a permanent magnet to maintain a set position without the constant
application of an external electrical current. The latching
solenoid 120 requires energy only for transitioning between the ON
and OFF states and thus it is suitable for low power applications.
Battery pack 130 is waterproof sealed and includes batteries that
provide power to the electronic showerhead 100. Battery pack 130 is
located above the bottom component 101 within the area 190 that is
normally dry. In one example, the battery pack is sealed closed
with an O-ring and this prevents exposure of the battery to
humidity or accidental splash back.
[0068] Referring to FIG. 7, FIG. 10A-FIG. 11B, the two-component
bottom portion 101 includes the top component 104 that is stacked
above the bottom component 106 and an O-ring 115 arranged between
the top and bottom components 104, 106. The two components 104 and
106 are held together with screws 107 that are threaded through
recessed through-openings 107a formed in the perimeters of the top
and bottom components 104, 106. Screws 107 are not visible from the
top or the side of the showerhead and are accessible from the
bottom surface 106a of the bottom component 106. The bottom surface
104b of the top component 104 includes a recessed area 105 and the
top surface 106b of the bottom component 106 includes a recessed
area 109. Recessed areas 105 and 109 are arranged opposite to each
other and are sealed closed together with the O-ring 115 that is
placed within a groove 115a surrounding the recessed area 109. A
closed sealed space 200 is formed between the recessed areas 105
and 109 and water exiting the inlet pipe 92 from the bottom 121 of
the solenoid 120 enters the closed sealed space 200 and exits
through the openings 110 in the bottom component 106. This
arrangement of the top and bottom components 104, 106 keeps the
water flow within the small volume of the closed and sealed space
200 between the recessed areas 105 and 109, while the remaining
components remain dry on top of the bottom portion 101. The volume
in space 200 is constrained in size such that it best meets the
following two requirements: [0069] a) Large enough to serve as a
constant-pressure reservoir for all nozzles (in the limit where it
becomes smaller and smaller, the downstream nozzles get less flow
than upstream ones) [0070] b) Small enough to keep the device
compact and preserve dry space for other components within the
showerhead. Keeping it small also helps to decrease the thermal
mass of the showerhead, resulting in quicker warm-up times for the
shower when it is first started at the beginning of a shower
session. Additionally, a smaller space results in the reduction of
hydrostatic pressure forces on the system, enabling further weight
reduction and ease of manufacture.
[0071] The top component 104 includes a through-opening 116 that is
configured to receive the exiting pipe 121 from the solenoid 120.
Top component 104 also includes through openings 118a and 119a that
are shaped and dimensioned to receive the ON/OFF power switch 112
and the sensor 108, respectively. Bottom component 106 also
includes through openings 118b and 119b that are concentric and
coaxially arranged with openings 118a, 119a and are also shaped and
dimensioned to receive the ON/OFF switch 112 and the sensor 108. In
one example, the two-component bottom portion 101 is made of metal
and the top cover 102 is made of plastic that may be colored.
[0072] Referring to FIG. 13, in operation, when a person or an
object steps under the showerhead device 100, the IR beam 150 is
interrupted and the sensor 108 sends a signal to the solenoid 120
that turns the flow of the water in the water stream 180 on. When
the person or the object steps away from the showerhead device 100,
the IR beam 150 reverts to an uninterrupted state and the sensor
108 sends another signal to the solenoid 120 that turns the flow of
the water in the water stream 180 off. In order to ensure reliable
and repeatable operation of the ON/OFF function, the sensor 108 is
positioned in area B, that is not within but away and above the
openings 110 that form the spray nozzle in area A. In this
arrangement the water starts to flow below the sensor 108 and
continues to fall away from the sensor 108 and forms the parabolic
water stream 180 that curves away from the sensing IR beam 150.
This geometric configuration is critical for the reliable operation
of the sensor 108, because it prevents auto-triggering and any
unintended persistence of the sensor 108 in the ON-position. This
design also provides adequate water flow in the water stream 180
for providing satisfactory shower coverage and experience. In the
example of FIG. 13, the showerhead 100 is arranged at an angle a2
relative to the horizontal axis X and the sensor 108 is positioned
at a distance d1 away and above the openings 110 in area A, and is
oriented so that it is parallel to the bottom surface of bottom
component 106. In some embodiments distance d1 is adjustable. In
other embodiments, sensor 108 is mounted on a pivoting gimbal so
that the angle between the sensor 108 and the bottom surface of the
bottom component 106 is also adjustable. The IR sensing zone 150 is
arranged so that it forms a conical beam having an internal cone
angle a1. The ON/OFF power switch 112 for the electrical power is
co-located within the IR sensing zone 150 and is set so that when a
user powers the showerhead device OFF, the solenoid 120 is first
latched into the "open" state. In this "open"/OFF state, the
electronic showerhead 100 functions like a typical showerhead that
is controlled by manual valves. Sensor 108 may also be programmed
to switch the solenoid 120 into the "open" state prior to powering
off.
[0073] Furthermore, in order for the showerhead 100 to work as an
intermittent showerhead that is responsive to people of average
size, the shower sensor 108 needs to have a suitable detection
range 160. In one example, the target sense distance 160 is in the
range of 12'' to 24'' inches. In order for the shower stream 180 to
be pleasant to the user and for the sensor to be inexpensive, the
detection area 150 must not be a line but rather a region of space.
This is accomplished by selecting a sensor 108 with an adequate
cone angle a1. Introducing a wide detection area 150, however,
opens up the possibility of sensor self-triggering events in which
the water emanating from the showerhead 100 triggers the sensor 108
to remain activated temporarily or indefinitely, whether or not a
person is in fact in the detection area 150. In order to avoid such
a problem, the detection area beam 150 must not (or only minimally)
intersect the flow path of water 180. There are many variables that
govern this relationship, which are described in more detail below.
The key variables that determine the "sweet spot" area 170 include
the sensor placement distance d1, the sensing beam cone angle a1,
the angle a2 of the showerhead relative to axis X (i.e., the
floor), the angle of the sensor 108 relative to the bottom surface
of 106 and the water nozzle size (i.e., diameter of openings 110)
and number. [0074] i) Sensor placement relative to water exit,
distance d1. The farther the sensor 108 is away from the water
exit, the less likely self-detection is. However for aesthetic and
usability purposes, this distance d1 should be kept to a minimum.
For example, if the sensor 108 is too far away from the water
stream 180, the trigger zone won't be in a flow area--the user will
turn on the shower but not get wet. In one example, this distance
d1 is in the range of 0.5'' to 2'' inches. In another example,
distance d1 is 1.375'' inches. In other examples, d1 is adjustable.
[0075] ii) Sensor internal cone angle (a1). Decreasing this angle
a1 minimizes the probability of self-detection, but also shrinks
the trigger zone. In one example this angle a1 is in the range of
10 to 45 degrees. In another example, a1 is 15 degrees. [0076] iii)
Angle of the showerhead relative to floor (a2). In one example,
this angle is user-adjustable, ranging from about 35 degrees to
about 60 degrees. This angle affects the trajectory of the water
exiting from the shower, which is additionally influenced by
gravity. The shower must work as intended throughout this range.
[0077] iv) Angle (a3) of the sensor 108 relative to the bottom
surface of the bottom component 106 of the showerhead. In one
example, this angle is 90 degrees (the sensing beam emanates the
shower at the same slope as the water). Decreasing this angle, so
that the beam points away from the water, increases the maximum
sensing distance, at the expense of an increased disparity between
the sense area and flow area. [0078] v) Water nozzle size and
number. The smaller the diameter of the nozzles/openings 110 is
(and the fewer nozzles there are), the faster the water will exit
the shower and the straighter (less curved) its parabolic
trajectory 160 will be. It is possible to tune the nozzle diameter
and shape so that the tangency point between the water path 180 and
the sensor cone 150 (either coincident to or offset from the sensor
cone) is as close as possible to the target range (.about.12-24''
in one example). This tangency allows for the watered area to be as
close as possible to the sensor area without a self-trigger event,
over the greatest vertical delta (to accommodate users of different
heights). This defines the "sweet spot" area 170. Tuning water
nozzle size also affects how much the nozzles "mist," which can in
turn affect the likelihood of self-trigger events. Lastly, tuning
water nozzle size and number also affects the feel of the shower
(in pressure and volume of water) and therefore should maintain
comfortable shower conditions throughout realistic shower flow
rates. In one example, the nozzle diameter is 0.040'' inch and
there are a total of 50 nozzles.
[0079] Among the advantages of this invention may be one or more of
the following. The electronic showerhead device of this invention
is a water (and by extension energy) saving device because it turns
the water automatically on when the user enters the sensing area
and turns the water automatically off when the user is not in the
sensing area, thereby reducing overall water consumption along with
the energy that would be required to heat and pump that water. The
electronic showerhead of this invention reliably and consistently
turns the water automatically on when a user enters the sensing
area and turns the water automatically off when the user is not in
the sensing area for users with different heights and perimeters.
The electronic showerhead device of this invention does not present
the problems of self-triggering or locking the showerhead valve in
the ON or OFF positions. The self-contained power source allows for
a user to retrofit a conventional showerhead and attach the
electronic showerhead without the need for special tools, special
plumbing or electrical connections or an electrician or a
plumber.
[0080] Referring to FIG. 14-FIG. 18, another embodiment of an
electronic showerhead device 200 according to this invention
includes a showerhead 201, a solenoid valve 220, a main flow stream
91 and a secondary flow stream 94. Showerhead 201 includes a flat
top component 202 and a flat bottom component 206. A cavity 203 is
formed within the inner side 206b of the bottom component 206 as
shown in FIG. 15. The showerhead 201 is attached to an inlet water
pipe 92 (also shown in FIG. 1) at the top via a swivel joint 260.
The solenoid valve 220 is positioned inline with the incoming water
stream 90 between the swivel joint 260 and the top component 202 of
the showerhead 201. Water exiting the solenoid valve 220 forms the
main flow stream 91. The secondary flow stream 94 is provided by a
pipe 223 extending from the main inlet pipe 92 and leading to the
top component 202.
[0081] Referring to FIG. 16, the bottom surface 206a of the bottom
component 206 includes an area A with openings 210 arranged so that
they form a spray nozzle. In operation, water 90 enters the
showerhead 201 through the inlet pipe 92 and exits through openings
210 and forms a parabolic water stream 180, as shown in FIG. 13 and
FIG. 19. Bottom surface 206a of the bottom component 206 also
includes a proximity sensor 208 located in area B of the bottom
surface adjacent to area A. In one example, proximity sensor 208 is
an Infrared (IR) sensor that emits a conical shaped IR beam 150
that extends above and adjacent to the exiting water stream 180. In
some embodiments, the conical shaped IR beam 150 is tangential to
the water stream 180. Sensor 208 looks for reflected beam signals,
and turns "ON" the solenoid valve 220 when a certain threshold of
reflected IR energy is met or exceeded, thereby allowing water
stream 180 to flow. When the certain threshold of reflected IR
energy is not met, sensor 208 turns "OFF" the solenoid valve 220
and the water stream 180 is interrupted. Bottom surface 206a of the
bottom component 206 also includes a temperature sensor 235 that
measures the temperature of water 90 (either directly or indirectly
via temperature measurement of surrounding enclosure(s)) and also
controls the ON/OFF function of the solenoid valve 220 via a
micro-controller unit (MCU) 250, as shown in FIG. 24. Temperature
sensor 235, proximity sensor 208 and MCU 250 are assembled onto a
printed circuit board (PCB) 238, which is located in area B of the
bottom surface 206a. A sensor lens 239 covers the PCB 238 and
protects the electronic components.
[0082] Referring to FIG. 29, the overall electronic system diagram
280 of the showerhead device 200 includes an inline generator 240,
an energy storage system 244, a power regulator 245, a
microcontroller 250, the solenoid 220, the temperature sensor 235,
switch 236, and the proximity sensor 208. The switch 236 is
configured with the MCU 250 so that when a user powers the
showerhead device "OFF" ("manual mode"), the solenoid 220 is
latched into the "open" state. In this "open"/OFF state, the
electronic showerhead 200 functions like a typical showerhead that
is controlled by manual valves. In this embodiment, switch 236 is
connected to the MCU 250 and is also used to adjust the
sensitivity/threshold of sensors 208 and 235.
[0083] Typically, a user turns on a showerhead handle to activate
the water flow through the showerhead. In the first initial
minutes, the remnant cold water from the pipes is purged and then
warmer water starts to flow through the showerhead. This cold water
purging process of turning on the showerhead and waiting for it to
get hot is a common nuisance problem for many people, and also
represents a big source of wasted water and energy, as the users
often overestimate the warm-up period and send hot water down the
drain that could have been used to shower with. The purpose of the
temperature sensor 235 is to automate this initial cold water
purging process. As shown in FIG. 24, the output of the temperature
sensor 235 is sent to the microcontroller 250 and the
microcontroller 250 sends a control output signal to the solenoid
valve 220 based on the water temperature reading. The control
output signal that the MCU 250 sends to the solenoid 220 controls
the ON/OFF operation of the solenoid and thereby the flow of the
water stream 180.
[0084] Referring to FIG. 25, this embodiment of the showerhead
device 200 also includes a secondary flow stream 94 provided by
pipe 223 (shown in FIG. 14 and FIG. 15). The secondary flow stream
94 provides a reduced flow exiting water stream 182 (shown in FIG.
20) that resolves a number of issues that may occur including the
following: [0085] Users forget to turn the main water-handle valve
to the off position after finishing their shower. [0086] Unintended
changes in water temperature can result from prolonged pause
periods.
[0087] Unintended changes in water temperature usually happen when
the shower is hooked up to a tankless water heater which shuts down
once load is removed. Unintended water temperature changes may also
occur when the plumbing system lacks check-valves, and is prone to
"back-flow," which primes the system with hot or cold water during
the shower pause periods. Maintaining a reduced flow exiting water
stream 182 during the shower pause periods reduces or eliminates
these problems for the vast majority of users. In one example, the
reduced flow water stream 182 has a flow rate between 0.1 and 1.0
gallons per minute. The secondary flow stream 94 is implemented as
having a fixed flow rate, as shown in FIG. 25. In the embodiment of
FIG. 26, the secondary flow stream 94 is implemented as having an
adjustable flow rate. An adjustable flow rate valve 275 is placed
in line with the secondary flow stream 94. In yet another
embodiment, the secondary flow stream 94 has a flow rate that can
be step-wise adjusted by using nozzles 270 of different sizes that
lead to different flow rates, as shown in FIG. 27. In yet other
embodiments, the secondary flow stream 94 is implemented via a
3-way valve.
[0088] This embodiment of the showerhead device 200 also includes
an internal generator 240 and an energy storage system 244.
Generator 240 is located within cavity 203, as shown in FIG. 15 and
is covered with a generator cap 242. Energy storage system 244 is
located on top of the top cavity cover 202. Generator 240 is
powered by the water flow through the main flow 91 and stores
energy in the energy storage system 244. The stored energy is used
to power the electronic components 238 of the showerhead device
200, as shown schematically in FIG. 28. In one example, generator
240 is a turbine system. Including a water-powered generator 240 in
the showerhead device eliminates the need for users to replace
batteries, which adds to the convenience of the device and also
makes it more eco-friendly, by reducing the waste associated with
depleted battery disposal. The generator output may also be used as
a signal to indicate when the main flow 91 is activated. This
process generates data which can be used to enable an accurate
calculation of overall water usage and water savings. The
water-powered generator 240 is designed to provide ample power to
enable the showerhead device operation. Excess power generated by
the generator 240 is diverted to the energy storage system 244.
Usable energy is generated when the main flow path 91 is open. In
other embodiments, the generator 240 is designed to create useable
voltages/current from the secondary signal stream 94, as well. The
energy storage system 244 is charged by the generator 240, and when
the water is paused or partially restricted, the sensors 235, 208
continue to function via the energy in the energy storage system
244, as shown in FIG. 28. In one example, the energy storage system
244 includes a battery and/or a capacitor.
[0089] The operation of the showerhead device 200 is described with
reference to FIG. 19-FIG. 23. Initially the user turns on the
showerhead handle and water flows through the inlet pipe 92 into
the showerhead 201, as shown in FIG. 19 (302). The valve 220 starts
in the "open" position such that water flows through the main flow
steam 91 and through the secondary flow stream 94 and forms the
main exiting water stream 180 and the secondary exiting water
stream 182, respectively, while remnant cold water from the pipes
is being purged. The in-line generator 240 generates power from
that cold water flow, and the power is used to power the device as
well as to charge the internal energy storage system 244. In this
phase, the temperature sensor 235 registers a "cold" temperature
235c, which is a temperature below a predetermined threshold value.
Once the cold water has been purged and the water reaches a
predetermined `hot" temperature 235h, the solenoid valve 220 is
turned off by the MCU 250 and the main water flow stream 91 is
paused, while the secondary reduced flow "signal stream" 94 remains
flowing resulting in having only the exiting water stream 182, as
shown in FIG. 20 (304). In one example, the predetermined threshold
temperature is 37.degree. C. At this point the proximity sensor
208, and the temperature sensor 235 are powered by the energy
storage system 244, and the device 200 is waiting for the user 80
to enter the shower. Next, the user 80 enters the shower area and
is detected by the proximity sensor 208. The proximity sensor 208
then turns on solenoid 220 and the main water stream 91 opens up
resulting in having the main exiting water stream 180 back on in
order to provide a full-slow shower experience, as shown in FIG. 21
(306). If the user 80 steps away from the showerhead 201, water
through the main flow 91 is temporarily paused while the "signal
stream" through the secondary flow 94 remains open, as shown in
FIG. 22 (308). This again results in turning the main exiting water
stream 180 off, while the secondary existing water stream 182 is
unaffected. Full water flow including both main exiting water
stream 180 and secondary exiting water stream 182 resumes again
when the user 80 steps back underneath the showerhead 200 and is
detected by the sensor 208, as shown in FIG. 23 (310). The logic
diagram of the valve, sensors and user positions is also depicted
in FIG. 30.
[0090] Referring to FIG. 31-FIG. 51D, another embodiment of an
electronic showerhead device 400 according to this invention
includes a showerhead 401, connecting to an inlet water pipe 92.
Showerhead 401 includes a flat top component 402, a midframe 404
and a flat bottom component 406. Midframe 404 is located in the
space formed between the top side 406b of the bottom component 406
and the bottom side 402b of the top component 402, as shown in FIG.
32. The showerhead 401 is attached to the inlet water pipe 92 at
the top via a swivel joint 462. Bottom component 406 includes
openings 410 arranged so that they form a spray nozzle. Bottom
surface 406a of the bottom component 406 also includes proximity
sensors 422 including emitter sensors 408 and receiver sensors 409
located in the low perimeter area A of the bottom surface 406a. In
one example, emitter sensors 408 are IR sensors that emit IR beams
that extend below and adjacent to the exiting water stream.
Receiver sensors 409 receive reflected IR and visible light
signals, and turn "ON" the solenoid valve 420 when a certain
threshold of reflected IR and visible light is met or exceeded,
thereby allowing water stream to flow. When the certain threshold
of reflected IR and visible light is not met, sensor 409 turns
"OFF" a solenoid valve 420 and the water stream is interrupted.
Bottom surface 406a of the bottom component 406 also includes a
temperature sensor 235 that measures the temperature of water 90
(either directly or indirectly via temperature measurement of
surrounding enclosure(s)) and also controls the ON/OFF function of
the solenoid valve 420 via a micro-controller unit (MCU) 250, as
shown in FIG. 24. Temperature sensor 235, and proximity sensors
408, 409 connect to the MCU 250 which is assembled onto a printed
circuit board (PCB) 238, as shown in FIG. 16. PCB 238 is located in
a watertight space 405 formed on the midframe 404. The top of space
405 is covered with the PCB cap 405a and the bottom of space 405 is
covered by a transparent cover 406c that protects the electronic
components, as shown in FIG. 42. Top component 402 also includes a
manual switch 465 for manual operation of the showerhead 400. This
embodiment of the showerhead device 400 also includes an internal
generator 440 that includes a rotor 444, shown in FIG. 50A-FIG.
50C. Generator rotor 444 is located within cavity 443 formed on the
midframe 404. Cavity 443 is covered with a generator cap 442 and
sealed with an O-ring. Generator rotor 444 is powered by the water
flow 90, as will be described below.
[0091] Referring to FIG. 33, a typical IR proximity sensor 480
includes an IR emitter 482 and an IR receiver 484 that are usually
located close to each other and are integrated into a single sensor
module. The IR proximity sensor 480 determines the distance of an
object 80, via a time-of-flight (TOF) measurement, whereby IR light
emitted by emitter 482 is reflected back by the object 80 and is
detected by the receiver 482. The difference in time between the
emitted IR light photons and the photons that are reflected by the
object 80 and are detected by the receiver 484 is used to determine
the distance separating the sensor 480 and the object 80. One of
the major challenges for using such distance sensors in foggy or
high humidity conditions is the high signal noise generated due to
light scattering and reflecting off the water molecules 485 in the
air. An example of this case is observed in a foggy shower room
after a hot shower on a cold day, which easily fools traditional
proximity sensors 480 into thinking that the target 80 is closer to
the sensor than it is in reality due to light scattering and
reflecting off of the fog/water molecules 485. A solution to this
problem is to maintain an optimal distance d between the sensor
receiver 409 and emitter 408, as shown in the improved sensor 422
of FIG. 34. If dense fog molecules 485 exist between the emitter
sensor 408 and the target object 80, separating the emitter 408 and
receiver 409 by a distance d enables a wider range of pathways for
light to reflect from the target object 80 and make its way back to
the receiver 409, thereby avoiding the more densely fogged area
directly above the target 80, as shown in FIG. 34. Doing so reduces
the chances of the light signal being affected twice (to and from)
by the same group of water molecules 485, and produces a stronger
signal for data processing. Furthermore, separating the emitter 408
and receiver 409 has the added benefit of reducing the chances of
crosstalk between these sensing modules, despite the existence of a
"fog bridge" between the two sensing modules that could pose a
problem with lower separation distances. However, when the distance
d between the emitter 408 and receiver 409 is too large, a stronger
IR emitter 408 and a wider viewing angle is needed, which limits
the practicality of the sensor 422. Higher power requirements pose
problems for battery-powered electronics in particular, where long
run-times require low power consumption. Furthermore,
emitter/receiver distances d which are too large produce blind
spots for objects in close proximity, since most of the energy from
the IR emitter 408 is focused in a cone with an included angle of
roughly 45.degree. degrees. Alternatively, a specialty lenses is
used to focus the IR emitter beam.
[0092] Referring to FIG. 35 and FIG. 51B, in one example, the
improved sensor system 422 of the present invention includes a
group of three IR sensor emitters 408a, a group of three IR sensor
emitters 408b and a sensor receiver 409 located in the middle
between sensor emitters 408a, and sensor emitters 408b at a
distance d of 2.5 cm. In other examples distance d is in the range
of 1 cm to 8 cm. Sensor receiver 409 includes an IR sensor receiver
409a and a visible light sensor (VLS) receiver 409b or a
combination IR/visible sensor. Traditional IR sensors are dependent
on the target IR reflectivity, which is a function of color,
texture, and other chemical, structural and surface material
properties that govern the reflection from the target surface. For
the case of human presence detection, that means that there is
often drastic performance variability between people of different
skin tones or hair color and texture. One solution to this problem
is to add a visible light sensor (VLS) into the design of the
presence detection system. This second VLS sensor 409b is capable
of detecting visible light reflected off target surfaces and having
wavelengths ranging from 400 nm to 800 nm. The VLS sensor 409b may
be a single color or multi-color detector, potentially enabled by
color filters. The VLS sensor 409b can be pixelated or just a
single area sensor. The secondary VLS 409b sensor can be a
standalone module or an integrated sub-system as part of a distance
measurement sensor. In order to successfully use visible light
sensor values as a proxy for distance (close proximity presence
detection), we take advantage of the fact that the amount of
visible light received by the sensor 409b changes as the user 80
moves toward or away from the sensor, as shown in FIG. 36. The VLS
sensor 409b picks up a summary of ambient light "brightness". The
VLS sensor 409b emits no visible light, and relies entirely on
ambient conditions for distance measurement. In normal cases,
shower surroundings, such as bathtubs, tiles, stone walls, glass
walls, white walls, among others, reflect more light than the human
body which has irregular surfaces, and varying skin tones. For this
reason, humans are normally "dimmer" than the background setting,
and result in lower VLS signal values as they approach the sensor
409b. As shown in FIG. 36, when the user 80 gets closer to the VLS
sensor 409b, distance A 421 decreases, resulting in less lighted
being reflect by the user's body and more light being reflected by
the surroundings, and therefore more "contrast" is detected. This
dynamic does not always hold true, as is in the case of a
light-toned human skin in a dark bathroom. However such scenarios
are overcome by using adaptive algorithms which effectively "learn"
their surroundings and the specific human skin colors and adjust
thresholds accordingly. In these cases, the additional data
gathered from a VLS sensor 409b are used to resolve issues when the
target object 80 has low IR reflectivity, and would otherwise be
difficult to reliably detect using traditional IR distance sensing
techniques.
[0093] FIG. 37 depicts signal data 429, 428 from a VLS sensor 409b
and an IR receiver sensor 409a, respectively. In general, higher IR
signals 428 indicate that the target 80 is closer to the sensor, as
more light is reflected. Accordingly, as a user steps back/away
from the showerhead the IR receiver signal 428 decreases, whereas
the VLS sensor signal 429 increases. As the user steps in/close to
the showerhead, the VLS sensor signal 429 decreases, and the IR
receiver signal 428 simultaneously increases.
[0094] FIG. 38 and FIG. 39 show how the combination of sensors can
be used to successfully eliminate false negatives that could
otherwise result from users with dark hair. When a user 80 has
darker hair, IR light is readily absorbed and the intensity of
reflected IR light decreases. The intensity of the dark hair signal
427 is similar to the decrease in the signal level 428a when the
user steps out of the shower. If one were relying only on one IR
receiver sensor to detect proximity, it would be difficult to
distinguish the decrease due to the dark hair absorption from the
case of the user stepping away. However, from the VLS sensor data
output 429b (low intensity), we can deduce that the user is still
in close proximity to the showerhead, and thereby avoid triggering
a false negative. Using complementary IR and VLS sensors as
described above enables a higher-accuracy proximity sensor in
challenging environments.
[0095] Referring to FIG. 40, a simple algorithmic logic 500 used in
combination with the IR and VLS sensors, to eliminate the risk of
false negatives includes the following steps. If the water is ON,
check if the IR sensor value is lower than an IR threshold (502).
If No, keep the water ON (504). If Yes, check if the VLS sensor
value is lower than a VLS threshold (506). If Yes, keep the water
ON (504). If No, turn off the water (508).
[0096] Because the sensor suite 408a, 408b, 409a, 409b includes
multiple sensor types (IR sensor and VLS sensors), we have designed
the supporting sensor enclosure 422a to enable the best performance
for both sensors. The sensors 408a, 408b, 409a, 409b are integrated
onto a custom designed printed circuit board (PCB) 238, that is
mounted in cavity 405 of the midframe structure 404. To minimize
crosstalk between the sensors, namely light leakage transmitted
either through the housing of the sensor or reflected by the
interfaces of sensor housing and the front plastic cover, the
sensor housing 422a material is selected to be light absorbing, as
shown in FIG. 41 and FIG. 42. This is implemented either by
selecting an inherently light-absorbing material for the sensor
housing, or by coating the housing with a paint or pigment that
absorbs light. While most IR sensors have a red-tinted front cover,
which is IR transmissive, but blocks most visible light, the front
cover 406c in this embodiment is completely transparent, as shown
in FIG. 42. This ensures that light can be efficiently received by
the VLS sensor 409b. In order to prevent unwanted noise caused by
visible light affecting the IR receiver as a result of this fully
transparent cover, a narrow-band IR receiver is used that doesn't
require a heavily tinted front cover to function normally.
[0097] In order to reduce the maintenance requirements, the
showerhead device 400 is powered by a built-in generator 440, shown
in FIG. 50A-FIG. 50B. Once again, the unique midframe 404 design is
critical in enabling the integration of the generator 440 into the
showerhead device in a functional, compact, and injection-moldable
fashion. Referring to FIG. 43, the primary pathway of water 90
going through the showerhead starts at the swivel ball 462, and
then is gated by the latching solenoid valve 420. If the valve is
open, water continues from the central orifice of the valve, headed
straight into the generator chamber 443, where it spins the turbine
444 and interior magnet 446. Coils 446s on a stator 445 which is
positioned inside of the circular magnet on the rotor generate a
current as a result of the changing magnetic flux. After spinning
the rotor blade 444a, the water becomes frothy and turbulent,
expanding in volume. Near the exit of the generator chamber 443,
there is an extra pocket of free volume 447, shown in FIG. 51A-FIG.
51B. As the water spins the micro-turbine 444, turbulent and
"frothy" liquid ends up in the turbulence pocket 447, where it has
space to settle without directly and negatively impacting the
established rotation of the turbine. Finally, water exits the
midframe 404, flowing downward from the turbulence pocket 447,
where it ultimately fills the nozzle-head cavity 403 and exits from
the shower nozzles 410.
[0098] The majority of plastic components throughout the system 400
are designed to be injection-moldable. The design for the
hydro-electric generation system 440 is tolerant of typical
variances in the size and fit of molded parts, which are generally
of looser tolerances than machined components. Instead of using a
positive-displacement based approach to spin the turbine (i.e. one
in which incoming water volume requires that the blades spin to
release an equal amount of water on the exiting side), a
momentum-based approach is used. In the momentum-based approach,
high-pressure water from the tap (typically .about.60 PSI) is
accelerated through a narrow orifice (typically .about.0.1''
diameter). The exact size of this orifice is based on the target
flowrate of the shower, as this orifice serves as the primary
flow-restriction device for the shower. High-velocity water then
hits the turbine blades 444a, which are spaced such that the active
blade never shadows an approaching blade from the high-velocity
water stream. The turbine blades 444a are also canted forming an
angle theta 449 with the vertical axis 449a, such that exiting
water is deflected downward, toward the floor of the midframe,
where it will ultimately exit to feed the showerhead nozzles
410.
[0099] As discussed above, the water pathway design is built around
providing the largest change in pressure at the generator orifice
and this is where energy is harvested from the pressurized water.
The nozzles 410, on the other hand, are designed to enable a
satisfactory shower experience with a minimal amount of
back-pressure. The details of this energy breakdown can be shown
via analysis of the flow coefficient (Cv) numbers, which are
designed as follows:
[0100] The total Cv of the system is about 0.178, in order to
provide about 1.55 GPM flow @ 80 PSI. The flow-range of interest
falls between 1.5 GPM to 4.0 GPM. [0101] 1. Swivel ball (assuming
0.312'' diameter). Cv on this comes to about 2.02 [0102] 2.
Solenoid valve: ideally use a low-resistance valve. Cv around 5.
[0103] 3. Nozzles (assuming 0.035'' diameter*50 nozzles in
parallel). Cv on this comes to approximately 1.14 after all
calculations. [0104] 4. Generator orifice: using the above numbers
as given, along with target system Cv, we back-solve for this and
the result is .about.0.18. This shows numerically that the
generator orifice is the biggest restriction in our overall system,
which means that the generator is the point at which the flow loses
most of its energy. If we use the 0.18 Cv for the generator to
solve for generator orifice diameter, we get about 0.093''.
[0105] To ensure the manufacturability of the device, it is
critical that the water pathway from the solenoid valve 420 to the
generator 440 is straight and smooth. In injection molding, this is
done with an extended metal pin that defines the interior of the
valve chamber and the pathway leading up to the generator. It is
critical that these structures exist on the same axis to enable
such a manufacturing technique.
[0106] As discussed above, the turbine blades 444a are not
completely perpendicular to the inline orifice 450. The angle theta
449 on the blade 444a helps to ensure the water flow exits the
generator without creating excessive turbulent flow inside the
generator chamber. The angle 449 also ensures that the turbine
blade 444a itself remains pushed upward during use, against the
bushing face which acts as a low-friction thrust bearing.
[0107] Both factors help to enhance generator performance, as extra
turbulent flow or friction from non-lubricious surfaces would
otherwise provide resistance to spinning and reduce power
output.
[0108] The generator system 440 is built around a stationary stator
445 which is actually exterior to the water pathway. The generator
cap 442 encapsulates and serves multiple purposes. Referring to
FIG. 46, generator cap 442 provides an axial space 453 for
receiving the rotor blade pin for the rotation of the turbine blade
around the axis of rotation 455. Bushing 452 fits inside the axial
space 453. Generator cap 442 also provides an exterior cavity 451
for the stator 445 to reside in. Cavity 451 is axially aligned with
the axis of rotation 455. Generator cap 442 also provides a mating
surface 456 which can be glued or ultrasonic welded to the plastic
midframe 404 to create a high-pressure seal (IPX7 water tight
performance).
[0109] As was described above, midframe 404 has a unique structure
that enables the reliable and inexpensive integration of all of the
key components that make the smart showerhead work. It combines all
of these sub-systems (generator, sensors, valve) with a minimal
number of O-rings, fasteners, and seals needed, and as a single
plastic part that is injection-moldable, it is ready for large
scale production.
[0110] As was mentioned above, the sensor suite 408a, 408b, 409a,
409b is designed to be located at the bottom of the showerhead
during use. This ensures that, as much as possible, the viewing
angle of the sensor is aligned with the user's body as opposed to
only their heads. Bodies provide a greater volume for detection and
a surface (user's skin) which is generally more reflective of IR
than hair, which is why they are a superior detection target. The
challenge with this design is that the sensors have to look through
an active water stream, and could potentially have drops of water
roll onto the sensor cover plate, thereby blocking its view. This
could result in significant false positives, and generally hinders
sensor performance. The solution to this problem involves extending
the rubber nozzles 410 further out of plane 406a by 2 mm or more,
as shown in FIG. 47. The solution also involves using a hydrophobic
material to form the nozzles 410. In one example, the nozzles 410
are made of thermoplastic elastomer (TPE). Both factors, along with
sharp nozzle edges, promote the formation of drops of water which
fall directly off of the nozzles as opposed to rolling off of them,
and down to the sensor cover.
[0111] In addition to the drip-formation strategy outlined above,
the nozzle pattern design is constructed such that, despite being
evenly spaced, there is a minimal number of nozzles directly
in-line with the IR and VLS receivers of the sensor module 422, as
shown in FIG. 48. In one example, the number of nozzles directly
in-line with the sensors is one or two, as shown in area 460. This
helps to limit the interference which can be caused by viewing a
water stream, and furthermore reduces the chances of a water drop
forming on the sensor cover in a position that would hinder
performance. A scratch resistant and anti-condensation coating is
also applied to the sensor cover, which further minimizes the noise
from water dripping down, and ensures that the sensor cover is
always clean and dry.
[0112] Several embodiments of the present invention have been
described. Nevertheless, it will be understood that various
modifications may be made without departing from the spirit and
scope of the invention. Accordingly, other embodiments are within
the scope of the following claims.
* * * * *