U.S. patent application number 12/156494 was filed with the patent office on 2009-12-03 for apparatus and system for automatic activation and de-activation of water flow.
Invention is credited to Carlos Pons.
Application Number | 20090293192 12/156494 |
Document ID | / |
Family ID | 41377923 |
Filed Date | 2009-12-03 |
United States Patent
Application |
20090293192 |
Kind Code |
A1 |
Pons; Carlos |
December 3, 2009 |
Apparatus and system for automatic activation and de-activation of
water flow
Abstract
The present invention comprises an apparatus and system for
automatic activation and de-activation of water flow to a sink,
bathtub, shower, or similar plumbing fixture. It can be readily
installed and operated safely using AC or DC power of varying
voltage, even in locations in which electrical power sources are
unreliable, inconsistent, or unstable. One or more normally closed
solenoid valves, activated by way of a capacitance-sensitive
electronic switch, control water flow. The switch functions in
response to contact by a part of the human body with one or more
touch-sensitive pads, which are designed to be resistant to
malfunctions associated with the buildup of soap and scum. A
programmable microprocessor periodically re-calibrates and resets
the system to ensure accurate function and longevity. The manner
and timing of water flow can be adjusted, and a by-pass is included
to allow continued access to water in the event of power
failure.
Inventors: |
Pons; Carlos; (Tampa,
FL) |
Correspondence
Address: |
SIDNEY WALLIS KILGORE
PENNINGTON, MOORE, WILKINSON, BELL & DUNBAR, PA, 2701 NORTH ROCKY POINT
DRIVE- SUITE 900
TAMPA
FL
33607-5975
US
|
Family ID: |
41377923 |
Appl. No.: |
12/156494 |
Filed: |
June 2, 2008 |
Current U.S.
Class: |
4/623 |
Current CPC
Class: |
E03C 1/05 20130101 |
Class at
Publication: |
4/623 |
International
Class: |
E03C 1/05 20060101
E03C001/05 |
Claims
1. An apparatus and system for automatic activation and
de-activation of water flow, comprising: One or more electrically
operated, normally closed solenoid valves, each connectably
interposed between a water inlet port and a water outlet port, and
each of which, when energized, will open to activate the flow of
water from its water inlet port to its water outlet port, and when
de-energized, will close to de-activate the flow of water from said
water inlet port to said water outlet port; One or more control
circuits for actuating the one or more electrically operated,
normally closed solenoid valves, said control circuits capable of
being open and closed by means of one or more capacitance-sensitive
electronic switches; One or more capacitance-sensitive electronic
switches, each embedded on a circuit board, for opening and closing
a control circuit, comprising one or more programmable
microcontrollers each with at least two memory registers, one or
more high-frequency, free-running, stable oscillators, one or more
dip switches or similar timing control devices, and one or more
low-signal dry-contact relays and associated relay contacts; One or
more touch-sensitive pads that, upon coming in contact with a part
of the human body, cause one or more of the one or more of the
capacitance-sensitive electronic switches to open or close;
Insulation for each of the one or more touch-sensitive pads to
separate the one or more touch-sensitive pads from any mounting
surfaces to which the one or more touch-sensitive pads may be
affixed; and A means of regulating the voltage to the components of
each of the capacitance-sensitive electronic switches that includes
one or more split winding step-down transformers and one or more
linear regulators.
2. The apparatus and system of claim 1 in which one or more of the
normally closed solenoid valves operate on AC current.
3. The apparatus and system of claim 1 in which one or more of the
normally closed solenoid valves operate on DC current.
4. The apparatus and system of claim 1 in which one or more of the
one or more programmable microcontrollers is programmed to reset
and recalibrate the measured capacitance of the system
periodically.
5. The apparatus and system of claim 4 in which one or more of the
one or more programmable microcontrollers is programmed to reset
and recalibrate the measured capacitance of the system
approximately once per hour.
6. The apparatus and system of claim 1 in which there are at least
four dip switches and at least one microcontroller is programmed
open one or more normally closed solenoid valves for so long as a
touch-sensitive pad is in contact with a part of the human body
when the first dip switch is the open position, irrespective of the
positions of the remaining three dip switches, and when the first
dip switch is in the closed position and the remaining three dip
switches are in the open position, to open one or more normally
closed solenoid valves from the time the touch-sensitive pad first
comes into contact with a part of the human body until, and only
until, the touch-sensitive pad comes into contact with a part of
the human body again.
7. The apparatus and system of claim 6 in which at least one
microcontroller is programmed to assign a water flow time interval
to one or more of the second and higher-numbered dip switches when
said switches are in the closed position, such that when the first
dip switch is in the closed position, and any other dip switches
are in the closed position, the assigned time intervals of the
closed second and higher-numbered dip switches will be summed and
the one or more normally closed solenoid valves will remain open
for the sum of those time intervals, or otherwise until such time
as the touch-sensitive switch again comes into contact with a part
of the human body.
8. The apparatus and system of claim 7 in which at least one
microcontroller is programmed to assign a water flow time interval
of 1 minute to the second dip switch, a time interval of 5 minutes
to the third dip switch, and a time interval of 10 minutes to the
fourth dip switch.
9. The apparatus and system of claim 1 in which one or more of the
one or more touch-sensitive pads is made of stainless steel.
10. The apparatus and system of claim 1 in which the insulation for
one or more of the one or more touch-sensitive pads is made of
rubber.
11. The apparatus and system of claim 1 in which the insulation for
one or more of the one or more touch-sensitive pads results in a
1/8 inch or greater separation between the touch-sensitive pad and
the mounting surface for said pad.
12. The apparatus and system of claim 1 in which one or more of the
one or more the split winding step-down transformers is capable of
accepting AC current of either 120 or 240 volts and reducing said
AC current to 6 volts.
13. The apparatus and system of claim 1 in which one or more of the
one or more linear regulators converts incoming voltage between 6
volts and 30 volts to 5 DC positive volts.
14. The apparatus and system of claim 1, further comprising a means
by which water from a water inlet port may be made to bypass the
one or more normally closed solenoid valves, said means to include
one or more pipes through which the water may flow, T-connectors to
divert water from a water inlet port into said one or more pipes
and then into a water outlet port, and one or more 1/4-turn ball
valves to activate or de-activate the flow of water through the
pipe to bypass the one or more normally closed solenoid valves.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
MICROFICHE APPENDIX
[0003] Not applicable.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] This invention relates to the field of fluid handling,
particularly with respect to the control of water flow for sinks,
baths, and showers.
[0006] 2. Description of Related Art
[0007] Traditional faucets for sinks, baths, and showers rely on
manually operated handles or knobs to activate and deactivate water
flow. The drawbacks associated with such manual means of
controlling the flow of water--the increased potential for
transmission of disease associated with multiple users, the
difficulty of use by persons with physical impairments, and the
waste of water when valves are not properly and timely shut
off--are well established.
[0008] Various devices allowing for the hands-free operation of
water faucets have been developed in an attempt to address these
issues. Many of these devices typically employ electrically
operated, normally closed solenoid valves that are interposed
between hot-water and cold-water inlets and outlets, often leading
to a single mixing faucet.
[0009] Ordinarily, some sort of switch means is employed to allow
hands-free activation and de-activation of the solenoids, thereby
allowing a user to control the flow of water through the faucet or
faucets. Among the various switch means employed are
touch-sensitive switches that take advantage of the biological
property of the human body to act as a good capacitor by storing
electrical charge. In contrast to electromechanical switches that
provide tactile feedback, such touch-sensitive switches have no
moving mechanical parts. When a part of the human body touches a
capacitance-triggered switch, the capacitance of an electrical
circuit is increased and the circuit, detecting this difference,
causes the switch to operate.
[0010] Existing devices utilizing capacitance-based touch-sensitive
switches are prone to failure or diminished function more often
than is desirable for a number of reasons. First, because their
capacitance-based switches must be placed in and around the outlets
through which the water flows for the convenience of the
user--e.g., near sink faucets, shower heads, bath tub faucets--soap
and scum accumulation can cause the switch to be triggered
unintentionally at arbitrary times. Second, capacitance-based
switches currently employed in these devices simply allow the
capacitance of the circuit to dissipate over time, which can
shorten the useful life of the switch and result in impaired
performance due to continual changes in electrical resistance
caused by variations in temperature, ambient humidity levels,
corrosion, and other factors.
[0011] The placement of existing devices are generally limited
because they are designed to function only in locations in which
electrical power sources are reliable, consistent, stable, and
safe. Most touch circuits require a 60-cycle power line to operate.
Users in locations in which such power sources are unavailable are
unable to take ready advantage of such devices. Moreover, these
devices normally provide only a pre-established, static way of
turning water flow on and off, i.e., touching the switch turns the
water on and touching the switch again turns the water off.
Frequently, however, those who would potentially benefit from such
devices have special requirements that would militate in favor of
controlling the way in which water flow was to be activated and
de-activated, and how long that water flow would last.
BRIEF SUMMARY OF THE INVENTION
[0012] The present invention comprises a new, improved, and
long-lasting apparatus and system for hands-free activation and
de-activation of water flow to a sink, bathtub, shower, or similar
plumbing fixture that can be readily installed and operated safely
even in locations in which electrical power sources are unreliable,
inconsistent, or unstable.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0013] FIG. 1 presents a lateral view of one embodiment of the
apparatus and system reflecting the interconnection of a
touch-sensitive pad and switch circuit board to solenoid valves(s)
and water ports.
[0014] FIG. 2 is an overhead perspective of the switch circuit
board illustrating one possible configuration of various elements
thereon.
[0015] FIG. 3 is an electric diagram of one possible arrangement of
various components regulating voltage for the switch components on
the switch circuit board.
[0016] FIG. 4 is an electric diagram of one possible arrangement of
various components for the switch on the switch circuit board.
[0017] FIG. 5 presents an overhead lateral view of an enclosure box
housing the switch circuit board and the solenoid valve(s).
[0018] FIG. 6 presents a lower lateral perspective of an enclosure
box, highlighting drainage outlets.
[0019] FIG. 7 is an overhead lateral perspective of the apparatus
and system as it might be installed for use with a sink.
[0020] FIG. 8 illustrates in a lateral view one possible
arrangement of the components of a touch-sensitive switch pad as
mounted.
[0021] FIG. 9 is an illustration of a water by-pass.
REFERENCE NUMERALS IN THE DRAWINGS
[0022] 1 120/240 volt AC lead
[0023] 2 Ground for 120/240 volt AC lead
[0024] 3 9-30 volt negative DC lead
[0025] 4 9-30 volt positive DC lead
[0026] 5 Switch circuit board
[0027] 6 Touch-sensitive pad
[0028] 7 Voltage input lead for first solenoid valve
[0029] 8 Voltage input lead for second solenoid valve
[0030] 9 Voltage output lead to first solenoid valve
[0031] 10 Voltage output lead to second solenoid valve
[0032] 11 Ground(DC)/Neutral(AC) lead from first solenoid valve
[0033] 12 Ground(DC)/Neutral(AC) lead from second solenoid
valve
[0034] 13 First solenoid valve
[0035] 14 Second solenoid valve
[0036] 15 Threaded male connector(s)
[0037] 16 Threaded female connector(s)
[0038] 17 First water inlet port
[0039] 18 Second water inlet port
[0040] 19 First water outlet port
[0041] 20 Second water outlet port
[0042] 21 Split-winding step-down transformer
[0043] 22 Linear regulator (IC1)
[0044] 23 Dip switches (SW1) or similar timing control
device(s)
[0045] 24 Microcontroller (IC3)
[0046] 25 Oscillator (IC2)
[0047] 26 First low-signal dry-contact relay (K2)
[0048] 27 Second low-signal dry-contact relay (K1)
[0049] 28 Cable (RG-174 or similar)
[0050] 29 Transistor (Q1)
[0051] 30 First capacitor (C1)
[0052] 31 Second capacitor (C2)
[0053] 32 Third capacitor (C3)
[0054] 33 Fourth capacitor (C4)
[0055] 34 First diode (D1)
[0056] 35 Second diode (D2)
[0057] 36 Third diode (D3)
[0058] 37 Fourth diode (D4)
[0059] 38 Fifth diode (D5)
[0060] 39 First resistor (R1)
[0061] 40 Second resistor (R2)
[0062] 41 Third resistor (R3)
[0063] 42 Fourth resistor (R4)
[0064] 43 5 DC positive volts
[0065] 44 First COM (common) relay contact
[0066] 45 Second COM (common) relay contact
[0067] 46 First NO (normally open) relay contact
[0068] 47 Second NO (normally open) relay contact
[0069] 48 Enclosure box
[0070] 49 Mounting surface for touch-sensitive pad
[0071] 50 Insulation
[0072] 51 Flat metal washer
[0073] 52 Electric connector
[0074] 53 Pressure metal washer
[0075] 54 Holding nut
[0076] 55 Threaded bolt
[0077] 56 Drainage outlet(s)
[0078] 57 Pipe(s)
[0079] 58 T-connector(s)
[0080] 50 1/4-turn ball valve(s)
DETAILED DESCRIPTION OF THE INVENTION
[0081] This invention utilizes one or more electronic switches, the
components of each of which are embedded on a circuit board, to
open and close one or more control circuits capable of actuating
one or more electrically operated, normally closed solenoid valves
to activate and de-activate the flow of water from water inlet
ports to water outlet ports. Each capacitance-sensitive switch
functions in response to contact by a part of the human body with
one or more touch-sensitive pads.
[0082] A lateral overall view of a preferred embodiment of the
apparatus and system reflecting the interconnection of a
touch-sensitive pad 6 and switch circuit board 5 to two solenoid
valves 13, 14, each of which is interposed between water inlet
ports 17, 18 and water outlet ports 19, 20 is presented in FIG. 1.
While the solenoid valve(s) may be joined to the water ports 17,
18, 19, 20 using various forms of connectors, in the embodiment
illustrated in FIG. 1, the solenoid valve(s) have threaded male
connectors 15 that are joined to companion threaded female
connectors 16 attached to the various water ports 17, 18, 19, 20.
Typically, but not always, the first solenoid valve 13 would
control a source of hot water, while the second solenoid valve 14
would control a source of cold water.
[0083] Power to the switch may be supplied by a grounded
alternating current (AC) of either 120 or 240 volts through the
120/240 volt AC lead 1 and ground lead 2 for the same.
Additionally, the switch is designed to operate on direct current
(DC) between 9 and 30 volts supplied by way of a positive DC lead 3
and a negative DC lead 4.
[0084] The one or more touch-sensitive pads 6 may be made of any
number of good-conducting, corrosive-resistant metals, such as
stainless steel. In one embodiment, a touch-sensitive pad 6 is
wired to the switch circuit board 5 by means of an RG-174 or
similar cable 28. When a part of the human body comes into contact
with the touch-sensitive pad 6, this causes the switch to be
activated, the accompanying capacitance-sensitive circuit closed,
and thus, each solenoid valve 13, 14 to be energized. A
touch-sensitive pad 6 can be positioned away from the switch
circuit board 5 itself in a location convenient to a user, e.g.,
adjacent to, or, or within a sink or other plumbing fixture. One or
more touch-sensitive pads 6 may be employed for the convenience of
the user, e.g., one to control the flow of hot water and one to
control the flow of cold water.
[0085] The system will accommodate the use of either AC- or
DC-powered solenoid valves 13, 14. The power source for the
solenoid valve(s) 13, 14 therefore may, but need not be, the same
power source used for the components of the switch. The voltage for
the solenoid valve(s) 13, 14 is first carried from input leads 7, 8
to the switch circuit board 6 via the COM contact(s) 44, 45 (see
FIG. 4), then is output from the NO contact(s) 46, 47 (see FIG. 4)
to the solenoid valve(s) 13, 14 by way of output leads 9, 10,
allowing each solenoid valve 13, 14 to be energized when the switch
is activated and the accompanying circuit closed. When energized,
each normally closed solenoid valve 13, 14 opens to activate the
flow of water. When de-energized, each solenoid valve 13, 14
closes.
[0086] One possible arrangement of various components of a switch
circuit board 5 is illustrated in the overhead view presented by
FIG. 2. As previously noted, the switch can be powered either by a
120 or 240 AC voltage source through a AC lead 1 and ground lead 2,
or by a DC source operating at between 9 and 30 volts through
separate positive and negative leads 3, 4. The incorporation of a
split-winding step-down transformer 21 acts as a safety feature to
avoid high-voltage AC current from migrating through the system and
causing potential harm to the user. A linear regulator 22, such as
an IC1 linear regulator, is employed to regulate the voltage to
ensure a positive output of 5 volts 43 to the components of the
switch.
[0087] It order to expand the range of power environments in which
the apparatus and system will work, and take advantage of DC
sources of power, a separate high-frequency, free-running, stable
oscillator 25, such as an NE555 oscillator IC2, is employed in the
capacitance-sensitive circuit. Normal oscillation, in one
embodiment, typically runs about 270 KHz, but drops to about 100
KHz when a part of the human body comes into contact with the
touch-sensitive pad 6, lowering the capacitance of the circuit.
[0088] When power is supplied to the system, a programmable
microcontroller 24 with at least two memory storage registers, such
as a microcontroller IC3, initializes and proceeds to determine the
frequency of the oscillator 25 by taking two measurements to
determine its period across a few microseconds. These values are
placed into separate memory storage registers within the
microcontroller 24 that, in the case of the IC3, would typically be
registers SAMP1 and SAMP2. The values of these two measurements,
taken milliseconds apart, are expected to be relatively close to
one another. A pre-determined range of "allowable drift" values--in
one embodiment, between 80 and 120 pulses--are incorporated within
the computer code of the microprocessor 24 to enable it to evaluate
its measurement of the frequency of the oscillator 25. If either of
the two measurements of the oscillator 25 exceeds the range of
acceptable drift values, the microcontroller 24 will presume an
unacceptable level of instability is present and will reset the
system.
[0089] As long as the measured frequency of the oscillator 25 does
not exceed these pre-established values, the microprocessor 24 will
take no action, other than to reset and recalibrate the system
periodically. In one embodiment, this resetting and recalibration
occurs approximately once every hour. Rather than simply allowing
the capacitance of the apparatus and system to dissipate over time,
and to compensate for changes in resistance due to temperature,
humidity, corrosion, etc., by performing this periodic resetting
and recalibration, the microprocessor 24 minimizes malfunctions
that might cause the switch to engage at arbitrary times, and
improves the longevity of the apparatus and system. When a part of
the human body comes into contact with the touch-sensitive pad 6,
however, the measured frequency of the oscillator 25 drops. If the
net change in measurement of frequency exceeds a pre-established
minimum (`LO`) value--in one embodiment, this might be 15
pulses--then the microcontroller will proceed to take action based
on the settings of the dip switches or similar timing control
device(s) 23. Changes in the sensitivity of the touch-sensitive pad
6 can be made by adjusting the applicable range of acceptable drift
values in the computer code of the microprocessor 24.
[0090] Dip switches 23 allow the apparatus and system to be
flexibly adjusted with respect to the manner and timing of
activation and de-activation of water flow. In one preferred
embodiment, four side-actuated dip switches in a single unit, such
as a C&K BP04K, may be employed. If the first dip switch is
open (i.e., ungrounded) and the remaining three dip switches are
open as well, then the microprocessor 24 will cause the low-signal
dry-contact relay(s) 26, 27 to be activated and the solenoid
valve(s) 13, 14 open, i.e., water is allowed to flow, only while a
part of the human body is in contact with the touch-sensitive pad
6. As soon as the touch-sensitive pad 6 is no longer being touched,
the water flow ceases. By contrast, when the first dip switch is
closed and the remaining three dip switches are open, then the
microprocessor 24 will cause the low-signal dry-contact relay(s)
26, 27 to be activated and the solenoid valve(s) 13, 14 open, i.e.,
water is allowed to flow, until such time as the touch-sensitive
pad 6 again comes into contact with a part of the human body. Water
flow alternately will start and stop with each touch of the
touch-sensitive pad 6.
[0091] The second, third, and fourth dip switches can be used to
adjust the timing of the water flow, and can be programmed to
accommodate different time intervals to meet user requirements. For
example, the second dip switch could be programmed for one minute,
the third for five minutes, and the fourth for ten minutes. The
pre-programmed time interval for each of these three dip switches
is activated by closing the applicable dip switch. For example, if
the first dip switch is open and the second dip switch is closed,
the water will remain running for at least 1 minute after the user
contacts the touch-sensitive pad 6, regardless of whether the user
touches the touch-sensitive pad 6 again. Similarly, if the first
dip switch is open and the third dip switch is closed, the water
will remain running for at least five minutes.
[0092] By different combinations of open and closed settings, the
second, third, and fourth dip switches, in this example, would
allow the time of water flow to be adjusted in intervals of 1, 5,
6, 10, 11, 15, and 16 minutes to suit the requirements of the user.
The total time interval is the sum of the programmed times for each
of the closed dip switches. For example, closing the second and
third dip switch, but leaving the fourth open, will result in a
six-minute interval.
[0093] If the first dip switch is closed while any of the other dip
switches are closed, the user can cut off the flow of water by
touching the touch-sensitive pad 6 a second time, thus shortening
the time interval for the water flow established by the settings of
the second, third, and fourth dip switches. Touching the
touch-sensitive pad 6 again will initiate another full time
interval for the water flow.
[0094] FIG. 3 presents electric diagram of one possible arrangement
of a set of components regulating the voltage for the system,
located on the switch circuit board 6. It illustrates how voltage
from a 120-volt AC power source, by way of the split-winding
step-down transformer 21, is reduced to six volts. It further
reflects how a DC power source, which bypasses the split-winding
transformer 21, may be used in lieu of AC power. Finally, it
illustrates how the power from either source passes through the
linear regulator 22 to ensure uniform output of 5 DC positive volts
43 to power the switch components.
[0095] An electric diagram of one embodiment of the switch and its
components, as integrated with a touch-sensitive pad 6, appears as
FIG. 4. This shows how a touch-sensitive pad 6 may be attached to
the switch via a cable 28, such as an RG-174. In one embodiment,
the components determining the frequency of the oscillator 25
comprise two resistors 40, 41 (R2 and R3), a capacitor 32 (C3), and
the capacitance from the cable 23 and the touch-sensitive pad 6
itself. The diagram further illustrates the inter-relationship of
the oscillator 25, the microprocessor 24, the dip switches 23, and
two low-signal dry-contact relays 26, 27, one for each of two
solenoid valves 13, 14 (not pictured in FIG. 4), and the contacts
for the relays 44, 45, 46, 47 to which the voltage input leads 6, 7
and voltage output leads 8, 9 for the solenoid valves 13, 14 are
connected. The use of low-signal dry-contact relays 26, 27 allows
the system to handle any exterior voltage to power the solenoid
valves 13, 14 and ensures longer life for the relay contacts 44,
45, 46, 47.
[0096] FIG. 5 illustrates the incorporation of the one or more
solenoid valves 13, 14 and the switch circuit board 5 into an
enclosure box 48. This feature facilitates the installation of the
apparatus and system and protects the components inside it. By
dividing the sensitive electronic components on the switch circuit
board 5 and any high-voltage electric current from the components
through which the water passes, the enclosure box 48 provides an
added measure of safety, system integrity, and long life for the
apparatus and system. The inclusion of one or more drainage outlets
56 in the form of holes, slots, or other suitable apertures
provides a way for water to drain from the enclosure box 48 in the
event of a leak and prevent water from a leak from seeping into the
compartment of the enclosure box 48 housing the sensitive
electronic components on the switch circuit board 5 and any high
voltage AC current.
[0097] In FIG. 6, a lower lateral perspective of the enclosure box
48 is presented, highlighting drainage outlets 56. FIG. 7 is an
overhead lateral perspective of the apparatus and system as it
might be installed for use with a sink, showing how the
touch-sensitive pad 6 might be positioned relative to the sink for
the convenience of a user. Optionally, the apparatus and system may
incorporate a water by-pass valve, reflected in FIG. 9, to allow
water to circumvent the apparatus and system in the event the
available sources of power for the system fail and the solenoid
valves 13, 14 remain closed.
[0098] A lateral view of one possible arrangement of the components
of the touch-sensitive pad 6 as mounted is illustrated in FIG. 8.
The touch-sensitive pad 6 passes through a mounting surface 49. The
touch-sensitive pad 6 is separated from the mounting surface 49,
which could be one or more of any number of materials, such as
ceramic, metal, or title, by suitable insulation 50, such as
rubber. A flat metal washer 51 abuts the insulation 50 on the side
of the mounting surface 49 opposite the touch-sensitive pad 6. A
pressure metal washer 53 and holding nut 54 secure an electric
connector 52 against the flat metal washer 51 and about a threaded
bolt 55. The cable 28 is attached to the electric connector 52. The
insulation 50 prevents the low voltage current of the apparatus and
system from making contact with the mounting surface 49, and in
addition, prevents the accumulation of soap, scum, residues, etc.
between the touch-sensitive pad 6 and the mounting surface 49,
which aids in preventing malfunctioning of the switch and
foreshortened apparatus and system life.
* * * * *