Note: Descriptions are shown in the official language in which they were submitted.
WIRELESS VARIABLE PRESSURE SPRAYER AND METHOD
PRIORITY CLAIM
This application claims priority from Provisional Patent Application Serial
No.
63/019,608, filed May 4, 2020, the contents of which are incorporated by
reference into this
utility application.
TECHNICAL FIELD AND BACKGROUND OF INVENTION
This invention relates to a variable pressure sprayer that uses a wireless
signal from the
spray gun to vary the pressure and/or flow rate with which a liquid is
dispensed from the sprayer.
Prior art sprayers work on the principle that when the user opens the sprayer
nozzle
through the trigger mechanism, the pressure in the system drops and a pressure
switch built into
the pump senses the pressure drop and closes a switch turning the pump motor
on and thus the
sprayer to start spraying. When the user closes the spray nozzle by releasing
the trigger
mechanism the pressure switch senses the pressure increase and opens a set of
contacts causing
the pump motor to turn off.
Conventional electric sprayers use a pressure switch to turn on and off the
electric pump.
When the user of the sprayer opens the valve on the spray gun the pressure in
the system drops
causing the pressure switch to turn on the pump and supply liquid. When the
user closes the
valve on the gun, the pressure increases causing the pressure switch to turn
off the pump. A
problem arises when a user utilizes a nozzle that does not allow enough flow
and causes the
pressure to increase enough in the system so that the pressure switch turns
off the pump even
though the user has the valve open on the gun. Since the valve is open, the
pressure immediately
drops below the pressure switch threshold causing the pump to restart. As soon
as the pump turns
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back on, the pressure rises past the threshold and the pump turns off again.
This on/off cycle
occurs rapidly and causes excessive wear on the pressure switch and the pump,
reducing the life
of the system or even causing complete failure.
As a separate matter, an electrical switch mounted in the spray gun may be
used to
control the operation of the motor operated liquid pump. Wires are then
necessary to control the
operation of the sprayer and may be damaged during normal use, rendering the
sprayer
inoperable. One such example is U.S. Patent Publication No. 2019/0263363. When
the user
opens the gun valve the switch also actuates a microswitch turning on the
pump. The pump runs
continuously until the user closes the valve, causing the microswitch to open
and shut off the
pump. This design requires control wires to be run from the sprayer unit to
the gun via the
system's hose. The control wires then must be protected from the environment
by re-wrapping
the hose with a protective coating. The control wires are still susceptible to
damage from field
conditions that can nick or cut the wires.
Therefore, in accordance with the invention of this application, the pump in
the sprayer is
controlled wirelessly by putting a module in the spray gun that sends a
wireless signal to a
receiver in the spray gun directing the pump to start. This eliminates the
need for a pressure
switch on the pump, a microswitch in the spray gun, and control wires wrapped
on the hose.
This wireless signal can then be used not only to turn the unit on and off,
but also to let the user
control the speed of the pump, thus controlling the output pressure and/or
flow rate. The signal
can also be used for feedback such that the user can "set" the desired
pressure and/or flow rate
and let the pump speed change according to flow such that the desired pressure
and/or flow rate
is constant.
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SUMMARY OF THE INVENTION
According to one aspect of the invention a wireless power sprayer is provided
that is
capable of dispensing a liquid from the supply tank at varying pressures
and/or flow rates.
According to one aspect of the invention a wireless power sprayer is provided
that is
controlled wirelessly by providing a transmitter in a spray gun that sends a
wireless signal to a
receiver activating a pump that delivers liquid from a storage tank to the
spray gun.
According to another aspect of the invention a wireless power sprayer is
provided that
uses a speed control to vary the pressure and/or flow with which a liquid is
dispensed from the
pump.
According to another aspect of the invention a wireless power sprayer is
provided with a
trigger on the spray gun of the applicator wand that is actuated with an
electrical switch, or other
electrical circuit capable of sensing trigger actuation and a module that
sends the wireless signal
to the receiver for activating the pump.
According to another aspect of the invention a method of operating a wireless
variable
pressure sprayer is provided that uses a speed controller to vary the pressure
and/or flow rate
with which a liquid is dispensed from the sprayer.
These and other aspects of the invention are accomplished by providing a
wireless
variable pressure sprayer that includes a housing in which is mounted a
battery, a battery-
operated motor, a motor-operated liquid pump, and a speed controller module
capable of
receiving a wireless signal. A tank is provided and communicates with the pump
for holding a
supply of liquid. A user operable spray gun is connected for liquid flow
communication from
the tank. A wireless transmitter is positioned in the spray gun and adapted to
transmit a wireless
signal to a receiver/controller positioned proximate to the battery and motor-
operated liquid
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pump, adapted for supplying current from the battery to the motor sufficient
to cause the motor
operated liquid pump to deliver liquid through the spray gun and into an
applicator wand.
According to another embodiment of the invention, a liquid outlet from the
pump
includes a connector adapted to receive a hose.
According to another embodiment of the invention, an applicator wand is
provided
and is adapted for connection to the spray gun and hose for directing fluid
under pressure to a
desired target.
According to another embodiment of the invention, the spray gun, including a
trigger,
is positioned on the applicator wand and adapted to wirelessly transmit a
signal indicating the
pressure and/or flow rate of the liquid to be delivered from the pump to the
spray gun.
According to another embodiment of the invention, a variable pressure and/or
flow
rate controller is positioned on the housing and connected to the motor for
varying an output
pressure and/or flow percentage of the pump.
According to another embodiment of the invention, the battery supplies a
suitable
voltage, for example, 18 V direct current, to the motor that powers the pump,
the pump is
adapted to draw liquid from the tank through a pump input conduit, the pump
pressurizes the
liquid, and discharges the liquid into an output conduit that is connected
through a sidewall
of the housing to the hose.
According to another embodiment of the invention, the wireless variable
pressure
sprayer is adapted to supply liquid at a manually selectable high or low
pressure.
According to another embodiment of the invention, the wireless variable
pressure
sprayer is adapted to supply liquid at a manually selectable high or low flow
rate.
According to another embodiment of the invention, the pump is controlled
wirelessly
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via a signal transmitted from the spray gun to a signal receiver operatively
associated with
the motor indicative of an instruction to the pump to turn on.
According to another embodiment of the invention, the spray gun is adapted for
manual operation by a user wirelessly controlling the output pressure and/or
flow rate of the
liquid by operation of the spray gun.
According to another embodiment of the invention, a pressure transducer or
flow
meter is placed at the output of the motor operated liquid pump, the signal is
adapted for
being fed back to the electronic control module whereby the user can manually
set a desired
pressure and/or flow rate and the pump speed changes according to pressure
and/or flow rate
as determined by the pressure transducer or flow meter such that the desired
pressure and/or
flow rate is constant.
According to another embodiment of the invention, the trigger is provided with
two
positions correlated to the desired pressure, and a demand for high or low
pressure causes a
wireless signal to be transmitted from the electronic control module to a
receiver/controller
on the motor to transmit current from the battery to the motor sufficient to
cause the pump to
deliver the desired pressure and/or flow of liquid through the hose, the spray
gun and into the
applicator wand.
According to another embodiment of the invention, the trigger includes a
switch that
when switched on, causes the transmitter in the spray gun to transmit a signal
correlated to a
specific desired pressure within a predetermined range of pressures and/or
flow rate.
According to another embodiment of the invention, a method of providing a
liquid at
a variable pressure to an applicator wand includes the steps of providing a
housing on which
is mounted a battery, a battery-operated motor, and a motor-operated liquid
pump, a tank
Date Recue/Date Received 2021-05-04
communicating with the pump for holding a supply of liquid and a spray gun
connected for
liquid flow communication from the tank. A wireless transmitter is positioned
in the spray
gun and adapted to transmit a wireless signal to a receiver/controller,
signaling the battery to
transmit current from the battery to the motor operated pump sufficient to
cause the pump to
deliver liquid through the spray gun and into the applicator wand to
wirelessly control the
output pressure of the liquid by operation of the spray gun.
According to another embodiment of the invention, the method includes the step
of
supplying liquid at a manually selectable high or low pressure.
According to another embodiment of the invention, the method includes the step
of
supplying liquid at a manually selectable high or low flow rate.
According to another embodiment of the invention, the method includes the step
of
feeding back a pressure and/or flow rate signal to the electronic control
module whereby the
user can manually set a desired pressure and/or flow rate and the pump speed
changes such
that the desired pressure and/or flow rate is constant.
According to another embodiment of the invention, the method includes the step
of
transmitting a wireless signal correlated to a specific desired pressure
and/or flow within a
predetermined range of pressures and/or flows to the pump, determined by a
position of the
trigger that is correlated to predetermined range of pressures.
According to another embodiment of the invention, a method of providing a
liquid at
a variable pressure to an applicator wand includes the steps of providing a
housing on which
is mounted a battery, a battery-operated motor, and a motor-operated liquid
pump. A tank
communicates with the pump for holding a supply of liquid and a spray gun is
connected for
liquid flow communication with the tank. A wireless transmitter is positioned
in the spray
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gun and adapted to transmit a wireless signal to a receiver/controller,
signaling the battery to
transmit current from the battery to the motor sufficient to operate the motor
operated pump
to cause the pump to deliver liquid through the spray gun and into a manually-
directed
applicator wand at a manually selectable high or low pressure. The spray gun
is manually
operated to wirelessly control the output of the liquid by operation of the
spray gun. The
wireless signal is fed back to an electronic control module whereby the user
can manually set
a desired pressure that changes according to flow such that the desired
pressure is constant.
The wireless signal is correlated to a specific desired pressure and/or flow
rate within a
predetermined range of pressures and/or flow rates to the pump.
BRIEF DESCRIPTION OF THE FIGURES
The present invention is best understood when the following detailed
description of the
invention is read with reference to the accompanying drawings, in which:
Figure 1 is a top view of the wireless sprayer, including hose and applicator
wand;
Figure 2 is a front elevation of the wireless sprayer housing, with cover
removed,
including hose and applicator wand;
Figure 3 is a schematic flow chart of a two-speed wireless sprayer;
Figure 4 is a schematic flow chart of a variable speed wireless sprayer;
Figure 5 is a circuit diagram of a spray gun of a wireless sprayer according
to one
embodiment of the invention with two speed control;
Figure 6 is a circuit diagram of a tank unit of a wireless sprayer according
to an
embodiment of the invention with two speed control;
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Figure 7 is a circuit diagram of a spray gun of a wireless sprayer according
to another
embodiment of the invention with variable speed control; and
Figure 8 is a circuit diagram of a tank unit of a wireless sprayer according
to an
embodiment of the invention with variable speed control.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE
Referring now to Figures 1 and 2, wireless variable pressure sprayer 10
includes a
housing 12 that encloses the operating elements of the sprayer 10. The sprayer
10 may be
carried on the back of the user by a shoulder strap assembly, not shown, that
is mounted to the
back of the housing 12. The sprayer 10 may also be mounted on wheels so that
it can be rolled
instead of carried. The housing 12 encloses a tank 16 which will typically
hold approximately
15 liters of liquid. The tank 16 is accessed through a threaded cap 18.
A battery 30, such as a lithium ion battery, is mounted on the housing 12.
Liquid under
pressure is dispensed from the sprayer 10 through a hose 40 that connects to
an applicator wand
44. The applicator wand 44 includes a spray gun 46 with a trigger 48 that is
manually grasped by
the user, and which operates a valve, not shown, in the spray gun 46 that
permits the pressure of
the liquid to be controlled.
A variable pressure controller 50 is mounted externally to the side of the
housing 12 and
communicates with a controller housing 52 in the lower part of the housing 12.
The battery 30
supplies nominal 18 V current to a motor 54 that drives a pump 56. The pump 56
draws liquid
from the tank 16 through a pump input conduit that pressurizes the liquid and
discharges it into
an output conduit 60 that is connected through the sidewall of the housing 12
to the discharge
hose 40.
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Referring now to Figure 3, a two-speed version of the sprayer 10 is explained.
The
sprayer is manually set to ether a high or low pressure and/or flow rate. The
pump 56 in the
sprayer 10 is controlled wirelessly by a module in the spray gun 46 that sends
a wireless signal to
a receiver in the spray gun 46 signaling it to turn on. This eliminates the
need for a pressure
switch on the pump 56, and control wires wrapped on the hose 40. This wireless
signal can then
be used not only to turn the unit on and off, but also to let the user control
the speed of the pump,
thus controlling the output pressure and/or flow rate.
Referred to broadly as "Demand Signal", this may be depressing the trigger 48.
¨As
shown, a demand for high pressure or flow rate causes a wireless signal to be
transmitted from a
transmitter to a receiver/controller, signaling the motor 54 to operate at a
set high speed
determined by the current and voltage supplied by the controller. The high
motor speed causes
the pump 56 to deliver liquid at a high pressure and/or flow rate of liquid
through the hose 40,
through the spray gun 46 and into the wand 44.
Conversely, as shown, a demand for low pressure or flow rate causes a wireless
signal to
be transmitted from a transmitter to a receiver/controller, signaling the
motor 54 to operate at a
set low speed determined by the current and voltage supplied by the
controller. The low motor
speed causes the pump 56 to deliver liquid at a low pressure and/or flow rate
through the hose
40, through the spray gun 46 and into the wand 44.
A further demand signal from the transmitter either signals the
receiver/controller to
continue pumping at either high or low pressure or flow rate, or to turn off
power to the pump
56.
Referring now to Figure 4, a system is illustrated schematically that permits
variable
pressure and/or flow rate between a high and low range to be delivered.
Preferably, the sprayer
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has a master ON/OFF switch. When switched on, the trigger 48 of the spray gun
46, when
depressed, causes the transmitter in spray gun 46 to transmit a signal
correlated to a specific
pressure and/or flow rate within the permitted range of pressures. Upon
receipt of a demand
signal from the user depressing the trigger 48 a wireless signal is to be
transmitted from the
transmitter to a receiver/controller, signaling the motor 54 to operate the
pump 56 sufficient to
cause the pump 56 to deliver liquid at the specified pressure and/or flow rate
liquid through the
hose 40, through the spray gun 46 and into the wand 44.
Alternatively, a variable speed controller, such as a rotatable dial or user
operable
display, may be positioned on the spray gun 46 to allow the user to change the
signal the
transmitter emits and thus changing the pressure and/or flow rate of the
liquid to be delivered to
the wand 44.
As also shown in Figure 4, the user may increment or decrement the pump speed.
With a
demand signal from the user a signal is sent to check system pressure and/or
flow. With no
demand signal from the user, the power to the pump 56 is turned off.
Referring to Figures 5-8, circuit diagrams are provided for two iterations of
a wireless
sprayer, one having two-speed operation and one with variable speed operation.
As shown in Figure 5, the spray gun 46 includes a circuit 70 with a two-speed
on/off
function. The circuit 70 operates in a standby mode until a permanent magnet
operated by the
trigger 48 is moved by the trigger 48 into proximity of a Hall effect sensor.
A microcontroller
unit ("MCU") detects the Hall effect sensor signal and transmits via an
antenna a wireless signal
to command the motor 54 to operate the pump 56 to deliver liquid from the tank
16. The liquid
pressure and/or flow rate is user selectable with pump speed switches SW1 and
SWII. The
circuit 70 is powered by a coin battery, for example, a CR2032 battery. If the
battery power falls
Date Recue/Date Received 2021-05-04
below a threshold value the MCU triggers the LED flash display to indicate
that the battery
requires replacement.
Tank operation is shown in Figure 6. Delivery of liquid from the tank 16 is
initiated by a
wireless signal from the spray gun 46 containing trigger state and selected
pressure and/or flow
rate. A wireless receiver decodes the signal and sends a data protocol to the
MCU to initiate
operation of the tank 16. The lithium battery 30 delivers direct current to
the DC motor 54 and
provides MCU stable power via a linear regulator. The MCU delivers a pulse
wave modulated
("PWM") signal to drive a MOSFET according to the selected pressure and/or
flow rate
determined by the wireless command signal. The current sensing resistor
monitors the status of
the motor 54 to protect against an unwanted stall event. The MCU continually
detects the
voltage of the battery 30 and automatically shuts down the machine when the
voltage drops
below a threshold value.
Referring to Figure 7, a circuit 90 with an ON/OFF function with variable
speed control
is shown and explained. The circuit operates in a standby mode until a
permanent magnet
operated by the trigger 48 is moved by the trigger 48 into proximity of a Hall
effect sensor. The
MCU in the spray gun detects the Hall effect sensor signal and sends a
wireless signal via the
antenna. The signal contains trigger state and desired pressure and/or flow
rate. The signal is
received by another MCU located on the housing that produces a signal to
command the motor
54 to operate the pump 56 to deliver liquid from the tank 16. The user
controls the spray gun 46
by operation of an UP/DOWN switch that changes the wireless command signal-to
increase or
decrease power delivered to the motor 54 as needed to control output of the
pump 56 as desired.
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The circuit 90 is powered by a coin battery, for example, a CR2032 battery. If
the battery
power falls below a threshold value the MCU, which includes a built-in LCD
driver, triggers the
LCD display to indicate that the battery requires replacement.
Referring now to Figure 8, a circuit 100 operates the delivery of the liquid
from the tank
16. Delivery of liquid from the tank 16 is initiated by a wireless signal from
the spray gun 46
which activates operation of the motor 54. A wireless receiver decodes the
wireless signal and
sends a data protocol to the MCU to execute operation of the pump. The lithium
battery 30
delivers direct current to the motor 54 and provides MCU stable power via a
linear regulator.
The MCU delivers a PWM signal to drive a MOSFET according to the wireless
command signal. . A pressure and/or flow rate sensor is connected to the pump
output and there
is a feedback loop within the MCU that automatically adjusts the PWM duty
cycle in the motor
circuit to achieve the selected pressure and/or flow rate communicated through
the wireless
command signal from the spray gun. The current sensing resistor monitors the
status of the motor
54 to protect against an unwanted stall event. The MCU continually detects the
voltage of the
battery 30 and automatically shuts down the machine when the voltage drops
below a threshold
value. In order to save battery power, the pressure sensor and/or flow rate
sensor turns on via an
MCU command only if the motor 54 is running.
A wireless variable pressure sprayer according to the invention has been
described with
reference to specific embodiments and examples. Various details of the
invention may be
changed without departing from the scope of the invention. Furthermore, the
foregoing
description of the preferred embodiments of the invention and best mode for
practicing the
invention are provided for the purpose of illustration only and not for the
purpose of limitation,
the invention being defined by the claims.
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