Liquid atomizing apparatus for aerial spraying
"You take the blue pill and the story ends. You wake in your bed and you believe whatever you want to believe."
"You take the red pill and
you stay in Wonderland and I'll show you how deep the
rabbit-hole goes."
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United States Patent |
4,948,050 |
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Picot |
August 14, 1990 |
http://164.195.100.11/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL
&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=4,948,050.WKU.&OS
=PN/4,948,050&RS=PN/4,948,050
Abstract
A rotary liquid spray atomizer for aerial spraying is driven by a variable speed motor, driven in turn by power from a variable speed AC generator. The generator is driven from a power take-off from the engine of the spraying aircraft, a drive assembly includes a device for controlling the speed of the generator relative to the speed of the engine. The particularly convenient drive assembly between the generator and the power take-off is a hydraulic motor, which drives the generator, driven by a hydraulic pump driven from the power take-off. The speed of the hydraulic motor can be controllably varied. Conveniently the AC motor is a synchronous motor.
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Inventors: |
Picot; Jules J. C. (Simcoe Court, Fredericton, N.B. E3B 2W9, CA) |
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Appl. No.: |
306425 |
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Filed: |
February 6, 1989 |
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Current U.S. Class: |
239/171; 239/162; 244/136 |
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Intern'l Class: |
B64D 001/18 |
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Field of Search: |
239/171,155,162,670 244/136 |
References Cited [Referenced By]
U.S. Patent Documents
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Nov., 1950 |
Adams |
239/171. |
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Oct., 1955 |
Nissen |
244/136. |
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Feb., 1969 |
Taylor |
244/136. |
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Jul., 1969 |
Knowles |
239/171. |
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Mar., 1975 |
Sousek |
239/670. |
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Jul., 1976 |
Waldrum |
239/171. |
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Foreign Patent Documents |
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141689 |
Jun., 1951 |
AU |
239/162. |
Primary Examiner: Kashnikow; Andres
Assistant Examiner: Forman; Michael J.
Attorney, Agent or Firm: McFadden, Fincham, Marcus & Allen
Claims
I claim:
1. A liquid atomizing apparatus for aerial spraying comprising:
a rotatable atomizer;
a variable speed AC electric motor for driving said atomizer;
an AC generator for producing electric power to drive said electric
motor at a speed related to the speed of said generator; and
variable speed drive means for connection between said generator and a
power take-off of an engine of an aircraft used for aerial spraying,
said drive means including means for controllably varying the speed of
a motor means, said motor means controllably varying the speed of said
generator relative to the speed of said engine.
2. A liquid atomizing apparatus for aerial spraying comprising:
a rotatable atomizer;
a variable speed AC electric motor for driving said atomizer;
an AC generator for producing electric power to drive said electric
motor at a speed related to the speed of said generator; and
variable speed drive means for connection between said generator and a
power take-off of an engine of an aircraft used for aerial spraying,
said drive means including means for controllably varying the speed of
said generator relative to the speed of said engine, said variable
speed drive means includes a variable speed hydraulic motor, pump
means connected to said variable speed hydraulic motor, and control
means positioned between said pump means and said variable speed
hydraulic motor for controlling the flow of liquid from the pump means
to the hydraulic motor to vary the speed thereof.
3. An apparatus as claimed in claim 2, including means for feeding an
output from said variable speed AC electric motor, indicative of the
speed of said variable speed AC electric motor, to said control means.
4. An apparatus as claimed in claim 2, comprising a plurality of
atomizers each driven by a variable speed synchronous AC motor, and
means for connecting each AC motor to said generator.
5. An apparatus as claimed in claim 2, said pump means comprising an
hydraulic pump, and including:
a hydraulic liquid reservoir;
means connecting an outlet of said reservoir to an inlet of said
hydraulic pump;
a pipe connecting an outlet of said hydraulic pump to an inlet of said
control means;
a pipe connecting an outlet of said control system to an inlet of said
hydraulic motor;
and a pipe connecting an outlet of said hydraulic pump to an inlet of
said reservoir.
6. An apparatus as claimed in claim 5, including by-pass means
extending between said control means and said reservoir.
7. An apparatus as claimed in claim 5, wherein said reservoir, said
hydraulic pump, said control means, said variable speed hydraulic
motor and said generator are in the form of a unitary assembly.
Description
FIELD OF THE INVENTION
This invention relates to a liquid atomizing apparatus for aerial
spraying, and in particular relates to the provision of apparatus
which will give a liquid or solid-in-liquid suspension spray having
predetermined characteristics independent of the speed of the aircraft
carrying out the spraying.
SUMMARY OF THE INVENTION
In a conventional spray system, a series of rotatable baskets are
assembled on a wing of the aircraft. In this system, each basket is
rotated by a propeller which is rotated by the passage of the aircraft
through the air. The liquid to be sprayed is fed into the baskets. The
baskets are perforated and the fluid is emitted centrifugally through
the perforations. The droplet size is very dependent on the speed of
rotation of the basket.
With the speed of rotation of the basket being determined by plane
speed, the droplet size is determined. When the plane varies speed,
for example slowing down to turn round or other manoeuvre, the droplet
size increases. This is inefficient in that more liquid is required to
cover an area with large drops rather than with small drops, since it
has been determined that a range of drop sizes between 15 microns and
55 microns is most desirable for aerial spraying of coniferous tree
foliage.
A further disadvantage is the drag occasioned by the propellers for
the atomizing devices, increasing fuel consumption.
PREFERRED FEATURES OF THE INVENTION
The present invention provides for the atomizers to be driven by an
electrical motor. DC motors have been used but require heavy current
supply not readily available on many aircraft. In the present
invention, the atomizers are driven by relatively high voltage AC
motors, preferably synchronous motors, the power for which is supplied
from an AC generator which is driven from a power take-off on an
aircraft engine by a variable speed system. Preferably, the generator
driven by a hydraulic motor which is driven by a hydraulic pump,
driven by a power take-off, on an engine of the aircraft. A fluid
control system is provided for controlling the speed of the hydraulic
motor with the input of a frequency signal from a tachometer
associated with at least one of the spraying units. This is then
universally applicable to any aircraft with a power take-off
attachment point.
In its broadest concept, a liquid atomizing apparatus for aerial
spraying comprises a rotatable atomizer, a variable speed AC motor
driving the atomizer, an AC generator for producing electric power to
drive the motor at a speed relating to the power generator, and a
drive means for connection between the generator and a power take-off
of an engine of an aircraft used for aerial spraying, drive means
including means for controlling the speed of the generator relative to
the speed of the engine.
In accordance with a particularly preferred embodiment of the present
invention, a fluid atomizing apparatus for aerial spraying comprises:
at least one rotatable liquid atomizer driven by a synchronous AC
electric motor; an AC generator for producing electrical power for
driving electric motor; a variable speed hydraulic motor for driving
said AC generator; a hydraulic pump connected to said hydraulic motor
and control means between said pump and said motor for variably
controlling the flow of liquid from the pump to the motor; and means
for connecting the hydraulic pump to a power take-off on an engine of
an aircraft.
A preferred embodiment of the invention discloses a method of aerial
spraying comprising providing an aerial spraying aircraft with a
liquid atomizing apparatus, said apparatus including a rotatable
atomizer; a variable speed AC electric motor for driving said
atomizer; an AC generator for producing electric power to drive said
electric motor at a speed related to the speed of said generator; and
drive means for connection between said generator and a power take-off
of an engine of an aircraft used for aerial spraying, said drive means
including means for controlling the speed of said generator relative
to the speed of said engine, connecting said drive means to said power
take-off of said aircraft engine, to actuate said pump means when the
aircraft engine is operating to drive said motor means, and
controlling the speed of said motor means by controlling the output of
said AC generator while controlling the output of said pump means to
thereby drive said rotatable liquid atomizer and dispense atomizer
spray.
DESCRIPTION OF THE VIEW OF THE DRAWING:
The invention will be readily understood by the following description
in conjunction with the accompanying drawing which is a diagrammatic
illustration of one system, or form of apparatus.
DETAILED DESCRIPTION WITH RESPECT TO THE DRAWINGS:
In the drawing, an engine is indicated at 10 with a power take-off at
11. A hydraulic pump 12 is connected to the power take-off 11 by a
connector 13. Liquid, typically oil, is fed to the pump 12 from a
reservoir 14, oil from the pump going via a hydraulic fluid control
system 15 to hydraulic motor 16. Oil returns to the reservoir 14 from
the motor 16. A bypass 17 extends between the control system 15 and
the reservoir 14. The fluid control system 15 can be manually
controlled, auto-controlled, or both.
The hydraulic motor 16 drives an AC generator 18. A plurality of
rotating screen atomizers 19 are shown attached at a wing, depicted
generally at 20. Each atomizer is driven by a variable speed AC motor
21.
Liquid is fed to each atomizer through a pipe 22 and flexible tubes
23. Electrical connections 26 extend between generator 18 and motors
21. Exitation is provided at 27. Typically the generator produces
power at 208 V, 400 H.sub.z, three phase at 4000 R.P.M.
In the example illustrated, a tachometer connection 28 is provided on
at least one of the motors 21, and is connected to the control system
15.
The hydraulic pump provides a controlled, variable oil flow to the
hydraulic motor, to drive the generator 18 at a controlled, variable
speed to produce the desired voltage and frequency for operation of
the atomizers at a required speed of rotation.
The power required is easily generated, and there is reduced drag on
the aircraft. It is possible to maintain the speed of the atomizers
constant, and therefor the droplet size is also constant. The
invention is very suitable for small fields and similar areas, where a
constant aircraft speed is not readily achieved during the spray
application. The invention can be applied to helicopters, where other
aircraft could not be conveniently used.
The number of atomizers used can vary according to requirements.
Where, for any reason, it is desired to alter the droplet size, this
can very readily be provided by adjustment of the control system 15.
It is not necessary to change the atomizer. The speed of the electric
motors, and atomizers, is independent of the speed of the engine 10
and of the forward speed of the aircraft.
The hydraulic pump 12, control system 15, hydraulic motor 16 and
reservoir 14 can be made into a unitary assembly for mounting on the
aircraft, and conceivably could be mounted on the engine which is
driving the pump 12. Existing structure on an aircraft for holding
conventional atomizer sprays can be used for mounting the electrically
driven atomizers used with the present invention. The existing spray
liquid containers and feed mechanism can be utilized, enabling the
invention to be used on existing spraying aircraft.