U.S. patent application number 13/947684 was filed with the patent office on 2013-11-14 for mechanical vibration deicing system.
This patent application is currently assigned to Amihay Gornik. The applicant listed for this patent is Amihay Gornik. Invention is credited to Amihay Gornik.
Application Number | 20130299638 13/947684 |
Document ID | / |
Family ID | 40341861 |
Filed Date | 2013-11-14 |
United States Patent
Application |
20130299638 |
Kind Code |
A1 |
Gornik; Amihay |
November 14, 2013 |
MECHANICAL VIBRATION DEICING SYSTEM
Abstract
An aircraft deicing system including at least one motor
operative to drive at least one eccentric mass in rotational motion
and at least one displacer coupled to at least one location on at
least one aircraft surface and coupled to the at least one
eccentric mass such that forces produced by the rotational motion
of the eccentric mass are applied to the at least one displacer,
causing the at least one displacer to displace the at least one
aircraft surface in a plurality of directions at each of the at
least one location, thereby causing disengagement of ice from the
at least one aircraft surface.
Inventors: |
Gornik; Amihay; (Karmei
Yosef, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Gornik; Amihay |
Karmei Yosef |
|
IL |
|
|
Assignee: |
Gornik; Amihay
Karmei Yosef
IL
|
Family ID: |
40341861 |
Appl. No.: |
13/947684 |
Filed: |
July 22, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12672459 |
May 17, 2011 |
8517313 |
|
|
PCT/IL2008/001086 |
Aug 7, 2008 |
|
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13947684 |
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Current U.S.
Class: |
244/134F ;
244/134R |
Current CPC
Class: |
B64D 15/16 20130101;
B64D 15/20 20130101 |
Class at
Publication: |
244/134.F ;
244/134.R |
International
Class: |
B64D 15/16 20060101
B64D015/16; B64D 15/20 20060101 B64D015/20 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 8, 2007 |
IL |
IL185134 |
Claims
1. An aircraft deicing system comprising: at least one motor
operative to drive at least one eccentric mass in rotational
motion; and at least one displacer coupled to at least one location
on at least one aircraft surface and coupled to said at least one
eccentric mass such that forces produced by said rotational motion
of said eccentric mass are applied to said at least one displacer,
causing said at least one displacer to displace said at least one
aircraft surface in a plurality of directions at each of said at
least one location, thereby causing disengagement of ice from said
at least one aircraft surface.
2. An aircraft deicing system according to claim 1 and wherein said
at least one displacer is operative in a cyclic manner, wherein in
each cycle said at least one displacer is operative to displace
said at least one aircraft surface in a plurality of directions at
each of said at least one location.
3. An aircraft deicing system according to claim 1 and also
comprising: at least one ice thickness sensor for sensing an ice
thickness responsive characteristic of said at least one aircraft
surface; and at least one controller responsive to an output of
said at least one ice thickness sensor indicating said ice
thickness responsive characteristic of said at least one aircraft
surface for governing the operation of said at least one motor.
4. An aircraft deicing system according to claim 1 and wherein said
at least one motor drives said at least one eccentric mass in
rotational motion about a first axis and at least a portion of at
least one of said at least one eccentric mass is selectably
displaceable along a second axis generally perpendicular to said
first axis.
5. An aircraft deicing system according to claim 1 and wherein said
at least one motor comprises a plurality of motors, each of which
is operative to drive an eccentric mass in rotational motion; and
said at least one displacer comprises a plurality of displacers,
each of which is coupled to a location on said aircraft surface and
coupled to said eccentric mass such that forces produced by said
rotational motion of said eccentric mass are applied to said
displacer, causing said displacer to displace said aircraft surface
in a plurality of directions at said location.
6. An aircraft deicing system according to claim 5 and wherein each
of said plurality of motors and said eccentric mass and displacer
associated therewith is operated in a predetermined sequence with
respect to others of said plurality of motors, eccentric masses and
displacers associated therewith, thereby causing disengagement of
ice from said at least one aircraft surface.
7. An aircraft deicing system according to claim 6 and wherein said
predetermined sequence produces displacement of said aircraft
surface which proceeds therealong in a wavelike progression.
8. An aircraft deicing system according to claim 1 and wherein said
at least one aircraft surface comprises a leading edge of a
wing.
9. An aircraft comprising: an airframe including at least one
aircraft surface; at least one motor operative to drive at least
one eccentric mass in rotational motion; and at least one displacer
coupled to at least one location on at least one aircraft surface
and coupled to said at least one eccentric mass such that forces
produced by said rotational motion of said eccentric mass are
applied to said at least one displacer, causing said at least one
displacer to displace said at least one aircraft surface in a
plurality of directions at each of said at least one location,
thereby causing disengagement of ice from said at least one
aircraft surface.
10. An aircraft according to claim 9 and wherein said at least one
displacer is operative in a cyclic manner, wherein in each cycle
said at least one displacer is operative to displace said at least
one aircraft surface in a plurality of directions at each of said
at least one location.
11. An aircraft according to claim 9 and also comprising: at least
one ice thickness sensor for sensing an ice thickness responsive
characteristic of said at least one aircraft surface; and at least
one controller responsive to an output of said at least one ice
thickness sensor indicating said ice thickness responsive
characteristic of said at least one aircraft surface for governing
the operation of said at least one motor.
12. An aircraft according to claim 9 and wherein said at least one
motor drives said at least one eccentric mass in rotational motion
about a first axis and at least a portion of at least one of said
at least one eccentric mass is selectably displaceable along a
second axis generally perpendicular to said first axis.
13. An aircraft according to claim 9 and wherein said at least one
motor comprises a plurality of motors, each of which is operative
to drive an eccentric mass in rotational motion; and said at least
one displacer comprises a plurality of displacers, each of which is
coupled to a location on said aircraft surface and coupled to said
eccentric mass such that forces produced by said rotational motion
of said eccentric mass are applied to said displacer, causing said
displacer to displace said aircraft surface in a plurality of
directions at said location.
14. An aircraft according to claim 13 and wherein each of said
plurality of motors and said eccentric mass and displacer
associated therewith is operated in a predetermined sequence with
respect to others of said plurality of motors, eccentric masses and
displacers associated therewith, thereby causing disengagement of
ice from said at least one aircraft surface.
15. An aircraft according to claim 14 and wherein said
predetermined sequence produces displacement of said aircraft
surface which proceeds therealong in a wavelike progression.
16. An aircraft according to claim 9 and wherein said at least one
aircraft surface comprises a leading edge of a wing.
17. An aircraft deicing system comprising: at least one ice
thickness sensor for sensing an ice thickness responsive
characteristic of at least one aircraft surface; at least one
selectably controllable ice disengager operative to cause ice to
disengage from said at least one aircraft surface; and at least one
controller responsive to an output of said ice thickness sensor
indicating said ice thickness responsive characteristic of said at
least one aircraft surface for varying at least frequency of said
selectably controllable ice disengager.
18. An aircraft deicing system according to claim 17 and also
wherein said at least one selectably controllable ice disengager
comprises: at least one motor operative to drive at least one
eccentric mass in rotational motion; and at least one displacer
coupled to at least one location on at least one aircraft surface
and coupled to said at least one eccentric mass such that forces
produced by said rotational motion of said eccentric mass are
applied to said at least one displacer, causing said at least one
displacer to displace said at least one aircraft surface in a
plurality of directions at each of said at least one location,
thereby causing disengagement of ice from said at least one
aircraft surface.
19. An aircraft deicing system according to claim 18 and wherein
said at least one displacer is operative in a cyclic manner,
wherein in each cycle said at least one displacer is operative to
displace said at least one aircraft surface in a plurality of
directions at each of said at least one location.
20. An aircraft deicing system according to claim 18 and wherein
said at least one motor comprises a plurality of motors, each of
which is operative to drive an eccentric mass in rotational motion;
and said at least one displacer comprises a plurality of
displacers, each of which is coupled to a location on said aircraft
surface and coupled to said eccentric mass such that forces
produced by said rotational motion of said eccentric mass are
applied to said displacer, causing said displacer to displace said
aircraft surface in a plurality of directions at said location.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to deicing systems and
methodologies particularly suited for aircraft and to aircraft
employing such deicing systems and methodologies.
BACKGROUND OF THE INVENTION
[0002] The following publications are believed to represent the
current state of the art: U.S. Pat. Nos. 2,037,626; 2,135,119;
2,297,951; 2,201,155; 3,549,964; 3,672,610; 3,779,488; 3,809,341;
4,875,644; 4,399,967; 4,458,865; 4,501,398; 5,206,806 and
7,084,553.
SUMMARY OF THE INVENTION
[0003] The present invention seeks to provide a highly efficient
deicing system and methodology particularly suitable for aircraft
and aircraft employing such deicing systems and methodologies.
There is thus provided in accordance with a preferred embodiment of
the present invention an aircraft deicing system including at least
one motor operative to drive at least one eccentric mass in
rotational motion and at least one displacer coupled to at least
one location on at least one aircraft surface and coupled to the at
least one eccentric mass such that forces produced by the
rotational motion of the eccentric mass are applied to the at least
one displacer, causing the at least one displacer to displace the
at least one aircraft surface in a plurality of directions at each
of the at least one location, thereby causing disengagement of ice
from the at least one aircraft surface.
[0004] There is also provided in accordance with another preferred
embodiment of the present invention an aircraft including an
airframe including at least one aircraft surface, at least one
motor operative to drive at least one eccentric mass in rotational
motion and at least one displacer coupled to at least one location
on at least one aircraft surface and coupled to the at least one
eccentric mass such that forces produced by the rotational motion
of the eccentric mass are applied to the at least one displacer,
causing the at least one displacer to displace the at least one
aircraft surface in a plurality of directions at each of the at
least one location, thereby causing disengagement of ice from the
at least one aircraft surface.
[0005] Preferably, the at least one displacer is operative in a
cyclic manner, wherein in each cycle the at least one displacer is
operative to displace the at least one aircraft surface in a
plurality of directions at each of the at least one location.
Additionally or alternatively, the aircraft deicing system also
includes at least one ice thickness sensor for sensing an ice
thickness responsive characteristic of the at least one aircraft
surface and at least one controller responsive to an output of the
at least one ice thickness sensor indicating the ice thickness
responsive characteristic of the at least one aircraft surface for
selecting a rotational speed of the at least one motor.
[0006] Preferably, the at least one motor drives the at least one
eccentric mass in rotational motion about a first axis and at least
a portion of at least one of the at least one eccentric mass is
selectably displaceable along a second axis generally perpendicular
to the first axis.
[0007] In accordance with a preferred embodiment of the present
invention the at least one motor includes a plurality of motors,
each of which is operative to drive an eccentric mass in rotational
motion, and the at least one displacer includes a plurality of
displacers, each of which is coupled to a location on the aircraft
surface and coupled to the eccentric mass such that forces produced
by the rotational motion of the eccentric mass are applied to the
displacer, causing the displacer to displace the aircraft surface
in a plurality of directions at the location. Preferably, each of
the plurality of motors and the eccentric mass and displacer
associated therewith is operated in a predetermined sequence with
respect to others of the plurality of motors, eccentric masses and
displacers associated therewith, thereby causing disengagement of
ice from the at least one aircraft surface. Additionally, the
predetermined sequence produces displacement of the aircraft
surface which proceeds therealong in a wavelike progression.
[0008] Preferably the at least one aircraft surface includes a
leading edge of a wing. There is further provided in accordance
with yet another preferred embodiment of the present invention an
aircraft deicing system including at least one ice thickness sensor
for sensing an ice thickness responsive characteristic of at least
one aircraft surface, at least one selectably controllable ice
disengager operative to cause ice to disengage from the at least
one aircraft surface and at least one controller responsive to an
output of the ice thickness sensor indicating the ice thickness
responsive characteristic of the at least one aircraft surface for
varying at least frequency of the selectably controllable ice
disengager.
[0009] Preferably, the at least one selectably controllable ice
disengager includes at least one motor operative to drive at least
one eccentric mass in rotational motion and at least one displacer
coupled to at least one location on at least one aircraft surface
and coupled to the at least one eccentric mass such that forces
produced by the rotational motion of the eccentric mass are applied
to the at least one displacer, causing the at least one displacer
to displace the at least one aircraft surface in a plurality of
directions at each of the at least one location, thereby causing
disengagement of ice from the at least one aircraft surface.
Additionally, the at least one displacer is operative in a cyclic
manner, wherein in each cycle the at least one displacer is
operative to displace the at least one aircraft surface in a
plurality of directions at each of the at least one location.
[0010] In accordance with a preferred embodiment of the present
invention the at least one motor includes a plurality of motors,
each of which is operative to drive an eccentric mass in rotational
motion, and the at least one displacer includes a plurality of
displacers, each of which is coupled to a location on the aircraft
surface and coupled to the eccentric mass such that forces produced
by the rotational motion of the eccentric mass are applied to the
displacer, causing the displacer to displace the aircraft surface
in a plurality of directions at the location. Preferably, each of
the plurality of motors and the eccentric mass and displacer
associated therewith is operated in a predetermined sequence with
respect to others of the plurality of motors, eccentric masses and
displacers associated therewith, thereby causing disengagement of
ice from the at least one aircraft surface. Additionally, the
predetermined sequence produces displacement of the aircraft
surface which proceeds therealong in a wavelike progression.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will be understood and appreciated
more fully from the following detailed description, taken in
conjunction with the drawings in which:
[0012] FIG. 1 is a simplified illustration of an aircraft including
a deicing system constructed and operative in accordance with a
preferred embodiment of the present invention;
[0013] FIG. 2 is a simplified exploded view illustration of part of
a preferred embodiment of a deicing system suitable for use in the
aircraft of FIG. 1;
[0014] FIGS. 3A, 3B, 3C and 3D illustrate four typical stages in a
rotation cycle which drives a displaces coupled to an aircraft
surface in a deicing system of the type shown in FIGS. 1 and 2;
[0015] FIGS. 4A, 4B, 4C and 4D illustrate, in exaggerated form,
deformation of an aircraft surface responsive to operation of the
deicing system of FIGS. 1 & 2 at stages corresponding to those
shown in FIGS. 3A, 3B, 3C and 3D, respectively;
[0016] FIG. 5 is a simplified flow chart illustrating one
embodiment of control functionality employed in the deicing system
of FIGS. 1-4D;
[0017] FIGS. 6A and 6B, taken together, are a simplified flow chart
illustrating another embodiment of control functionality employed
in the deicing system of FIGS. 1-4D;
[0018] FIG. 7 is a graphical illustration useful in understanding
the control functionalities of FIGS. 5 and 6A-6B;
[0019] FIG. 8 is a simplified flow chart illustrating a further
embodiment of control functionality employed in the deicing system
of FIGS. 1-4D employing additional acceleration sensors and/or
strain gages;
[0020] FIG. 9 is a simplified illustration of an aircraft including
a deicing system constructed and operative in accordance with
another preferred embodiment of the present invention;
[0021] FIG. 10 is a simplified exploded view illustration of part
of a preferred embodiment of a deicing system suitable for use in
the aircraft of FIG. 9;
[0022] FIGS. 11A, 11B, 11C and 11D illustrate four typical stages
in a rotation cycle which drives a displacer coupled to an aircraft
surface in a deicing system of the type shown in FIGS. 9 and 10;
and
[0023] FIGS. 12A, 12B, 12C and 12D illustrate, in exaggerated form,
deformation of an aircraft surface responsive to synchronized
operation of multiple separate motor driven displacers of the type
illustrated in the deicing system of FIGS. 9-11D in accordance with
another preferred embodiment of the present invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0024] Reference is now made to FIG. 1, which is a simplified
illustration of an aircraft including a deicing system constructed
and operative in accordance with a preferred embodiment of the
present invention and to FIG. 2, which is a simplified exploded
view illustration of part of a preferred embodiment of a deicing
system suitable for use in the aircraft of FIG. 1.
[0025] As seen in FIG. 1, there is provided an aircraft 100
equipped with a deicing system constructed and operative in
accordance with a preferred embodiment of the present invention.
The deicing system is preferably located within the wings 102 of
the aircraft adjacent the leading edges 104 of the wings 102. The
deicing system may alternatively or additionally be located within
the tail or stabilizers of the aircraft.
[0026] It is a particular feature of the present invention that the
deicing system includes at least one motor operative to drive at
least one eccentric mass in rotational motion and at least one
displacer coupled to at least one location on at least one aircraft
surface, preferably the leading edge 104 of a wing 102, and coupled
to the at least one eccentric mass such that forces produced by the
rotational motion of the eccentric mass are applied to the at least
one displacer, causing the at least one displacer to displace the
at least one aircraft surface in a plurality of directions at each
of the at least one location, thereby causing disengagement of ice
106 from the at least one aircraft surface.
[0027] In the illustrated embodiment, a motor 110, preferably an
electric motor and alternatively a fluid driven motor, such as a
pneumatic motor, is disposed interiorly of each wing 102 adjacent
the leading edge 104 thereof and preferably alongside the aircraft
fuselage 112. A drive shaft 114 couples each motor 110, such as a
model 3863012C, manufactured by Faulhaber GmbH of Daimlerstrasse
23, 71101 Schonaich, Germany, to a series of displacer assemblies
116. It is appreciated that alternatively multiple motors 110 and
multiple drive shafts may each be coupled to a series of displacer
assemblies 116 at various locations within each wing.
[0028] Turning now particularly to FIG. 2, it is seen that each
displacer assembly 116 includes an elongate drive shaft portion
120, preferably having flattened portions 122 and 124 at ends
thereof and a flattened portion 126 generally central thereof.
Flattened portions 122 and 124 of elongate drive shaft portion 120
are secured as by respective set screws (not shown) to respective
first ends 128 and 130 of flexible couplings 132 and 134. Flexible
couplings 132 and 134 may be any suitable flexible couplings, such
as model CO76A-5M manufactured by Berg W.M., Inc. of 499 Ocean
Avenue, East Rockaway, N.Y. 11518 USA. Respective second ends 138
and 140 of flexible couplings 132 and 134 are preferably secured as
by respective set screws (not shown) to corresponding flattened
ends of drive shaft elements (not shown) which interconnect the
various displacer assemblies 116 to each other and to motor
110.
[0029] A pair of ball bearings 150 and 152, such as Model 34-5,
commercially available from Schaeffler Group--FAG GmbH of
Industriestrasse 1-3, Herzogenaurach 91074, Germany, are pressure
fit mounted onto drive shaft portion 120 between flattened portion
126 and flattened portions 122 and 124, respectively. A leading
edge attachment element 160 is mounted onto drive shaft portion 120
via ball bearings 150 and 152 which engage respective bearing
receiving apertures 162 and 163 formed in respective arms 164 and
165 and are fixed thereto by respective lock washers 166 and 167
and wave spring washers 168 and 169. Leading edge attachment
element 160 includes a leading edge attachment portion 170,
preferably integrally formed with radially extending pairs of arms
164 and 165 each joined by a radially extending generally planar
portion 171 and having a curved interior leading edge attachment
surface 172 which is fixedly adhered, as by an adhesive, such as
product no. 4132 Structural Adhesive Kit, commercially available
from 3M, St. Paul, Minn. 55144, USA, to a correspondingly curved
interior surface of leading edge 104 of wing 102.
[0030] An eccentric drive mass 180 is preferably fixedly mounted to
elongate drive shaft portion 120 for rotation together with drive
shaft portion 120 about an axis 182. The eccentric drive mass 180
is preferably fixedly mounted to elongate drive shaft portion 120
at flattened portion 126 by means of a pair of suitably configured
bracket elements 184 and 186 having respective facing recesses 188
and 190 having cross sectional configurations which respectively
match the cross sectional configuration of the drive shaft portion
120 at flattened portion 126. Respective ends 192 and 194 of
bracket elements 184 and 186 are retained within a suitable socket
196 of eccentric drive mass 180 by means of a retaining pin
198.
[0031] Preferably bracket elements 184 and 186 are held in place by
a pair of screws 200 and corresponding nuts 202, washers 204 and
lock washers 206.
[0032] An acceleration sensor 210, such as a model NMA 1213D
commercially available from Freescale Semiconductors Inc., 6501
William Cannon Drive West, Austin, Tex. 78735, USA, is preferably
mounted on at least one displacer assembly 116 on each wing of the
aircraft in order to serve as an ice thickness sensor, as is
described hereinbelow. A variable speed motor 212 having a mass 214
eccentrically mounted on an output shaft 216 thereof is mounted on
the same displacer assembly 116. Alternatively, the functionality
of motor 212 may be provided by motor 110, when operated at a
relatively low frequency, typically 20 Hz.
[0033] A deicer controller 220 preferably receives inputs from
acceleration sensors 210 associated with the various displacer
assemblies 116 and provides control inputs to motor 110. The
control logic preferably employed by deicer controller 220 is
described hereinbelow with reference to FIG. 5.
[0034] According to an alternative embodiment of the present
invention, an example of which is illustrated in an enlargement 230
in FIG. 2, some or all of mass 180 may be selectably displaced
along an axis 231, generally perpendicular to axis 182, such that
the effective distance of the mass 180 from axis 182 may be varied.
This provides an additional degree of freedom in controlling the
operation of the deicing system of the present invention. When the
mass 180 is relatively close to axis 182, it applies relatively
little force. As the mass 180 is positioned further from axis 182,
the rotation thereof produces corresponding greater force. Thus by
controlling the propinquity of mass 180 to axis 182, the amount of
force applied to the aircraft surface may be modulated and thus
controlled.
[0035] In the illustrated embodiment shown in enlargement 230, a
part 232 of mass 180 is mounted on a screw drive 234, which may be
driven by a motor 236 to adjust the positioning of part 232 of mass
180 along axis 231.
[0036] It is appreciated that flexible couplings 132 and 134 are
provided so that the force applied by mass 180 during rotation
thereof is applied to leading edge 104 through leading edge
attachment element 160 rather than through drive shaft 114 to other
displacer assemblies 116.
[0037] Preferably, additional acceleration sensors 310, such as
model NMA 1213D acceleration sensors commercially available from
Freescale Semiconductors Inc., 6501 William Cannon Drive West,
Austin, Tex. 78735, USA; are preferably mounted on surfaces 171 of
at least one displacer assembly 116 on each wing of the aircraft in
order to serve as ice presence sensors, as is described
hereinbelow. Acceleration sensors 310 are preferably arranged to
lie perpendicular to the surface of leading edge 104.
[0038] Additionally or alternatively to acceleration sensors 310,
strain gages 320, preferably strain gage 062AP commercially
available from Vishay Intertechnology Inc., 63 Lancaster Ave.,
Malvern Pa. 19355, USA, may be mounted onto the curved interior
surface of leading edge 104 of wing 102 on either side of curved
interior leading edge attachment surface 172. Attachment of the
strain gages 320 to the curved interior surface of leading edge 104
preferably employs an adhesive, such as M-Bond 200 Adhesive
commercially available from Vishay Intertechnology Inc., 63
Lancaster. Ave., Malvern Pa. 19355, USA.
[0039] A deicer controller 330 preferably receives inputs from
acceleration sensors 310 associated with the various displacer
assemblies 116 and strain gages 320 and provides on-off control
inputs to motor 110. The control logic preferably employed by
deicer controller 330 is described hereinbelow with reference to
FIG. 8.
[0040] It is appreciated that controllers 220 and 330 may be
integrated into a single controller. Reference is now made to FIGS.
3A, 3B, 3C and 3D, which illustrate four typical stages in a
rotation cycle which drives a displacer coupled to an aircraft
surface in a deicing system of the type shown in FIGS. 1 and 2, and
to FIGS. 4A, 4B, 4C and 4D, which illustrate, in exaggerated form,
deformation of an aircraft surface responsive to operation of the
deicing system of FIGS. 1 & 2 at stages corresponding to those
shown in FIGS. 3A, 3B, 3C and 3D respectively.
[0041] As seen in FIG. 3A, an eccentric drive mass 380 of displacer
assembly 382 is located along an axis 384 which passes through axis
182 (FIG. 2) and extends generally perpendicular to the plane
defined by the tangent 386 to the curved surface 388 of a leading
edge 390 to which curved interior leading edge attachment surface
392 of displacer assembly 382 is attached. Inasmuch as mass 380
lies beyond axis 182 with respect to surface 388, the displacer
assembly 382 is applying a pull force to the leading edge 390 along
axis 384.
[0042] As also seen in FIG. 3A, eccentric drive mass 400 of
displacer assembly 402 is located along an axis 404 which passes
through axis 182 (FIG. 2) and extends generally parallel to the
plane defined by the tangent 406 to the curved surface 408 of
leading edge 390 to which curved interior leading edge attachment
surface 412 of displacer assembly 402 is attached. Inasmuch as mass
400 lies along an axis which is not perpendicular to surface 408,
the displacer assembly 402 is applying a bending force to the
leading edge 390.
[0043] FIG. 4A shows, in an exaggerated manner the deformation of
the leading edge 390 corresponding to the operational state
illustrated in FIG. 3A. The extent of exaggeration is estimated to
be a factor of 40.
[0044] In FIG. 3B, eccentric masses 380 and 400 have been rotated
from the position seen in FIG. 3A. As seen in FIG. 3B, eccentric
drive mass 380 of displacer assembly 382 is not located along axis
384. Inasmuch as mass 380 lies along an axis which is not
perpendicular to surface 388, the displacer assembly 382 is
applying a bending force to the leading edge 390.
[0045] As also seen in FIG. 3B, eccentric drive mass 400 of
displacer assembly 402 is not located along an axis 404 but is
nearly perpendicular to axis 404. Inasmuch as mass 400 lies between
axis 182 and surface 406, the displacer assembly 402 is applying a
push force to the leading edge 390.
[0046] FIG. 4B shows, in an exaggerated manner the deformation of
the leading edge 390 corresponding to the operational state
illustrated in FIG. 3B. The extent of exaggeration is estimated to
be a factor of 40.
[0047] In FIG. 3C, eccentric masses 380 and 400 have been rotated
approximately 180.degree. from the position seen in FIG. 3A. As
seen in FIG. 3C, eccentric drive mass 380 of displacer assembly 382
is located along axis 384 which passes through axis 182 (FIG. 2)
and extends generally perpendicular to the plane defined by tangent
386 to curved surface 388. Inasmuch as mass 380 lies between axis
182 and surface 388, the displacer assembly 382 is applying a push
force to the leading edge 390 along axis 384.
[0048] As also seen in FIG. 3C, eccentric drive mass 400 of
displacer assembly 402 is located along axis 404 which passes
through axis 182 (FIG. 2) and extends generally parallel to the
plane defined by tangent 406 to curved surface 408. Inasmuch as
mass 400 lies along an axis which is not perpendicular to surface
408, the displacer assembly 402 is applying a bending force to the
leading edge 390.
[0049] FIG. 4C shows, in an exaggerated manner the deformation of
the leading edge 390 corresponding to the operational state
illustrated in FIG. 3C. The extent of exaggeration is estimated to
be a factor of 40.
[0050] In FIG. 3D, eccentric masses 380 and 400 have been rotated
further counterclockwise, as seen from the perspective of the
sectional illustration shown along lines A-A therein, from the
position seen in FIG. 3A. As seen in FIG. 3D, eccentric drive mass
380 of displacer assembly 382 is not located along axis 384.
Inasmuch as mass 380 lies along an axis which is not perpendicular
to surface 388, the displacer assembly 382 is applying a bending
force to the leading edge 390.
[0051] As also seen in FIG. 3D, eccentric drive mass 400 of
displacer assembly 402 is not located along an axis 404 but is
nearly perpendicular to axis 404. Inasmuch as mass 400 lies beyond
axis 182 with respect to surface 406, the displacer assembly 402 is
applying a pull force to the leading edge 390.
[0052] FIG. 4D shows, in an exaggerated manner the deformation of
the leading edge 390 corresponding to the operational state
illustrated in FIG. 3D. The extent of exaggeration is estimated to
be a factor of 40.
[0053] Reference is now made to FIG. 5, which is a simplified flow
chart illustrating control functionality employed in the deicing
system of FIGS. 1-4D, and to FIG. 7. As seen in FIG. 5, a control
signal is preferably supplied by controller 220 to motors 212,
causing the motors 212 to accelerate from rest to 500
revolutions/second. Acceleration sensors 210 measure acceleration
and provide corresponding output indications to controller 220.
Controller 220 calculates vibration amplitude vs. rate of rotation,
which represents the frequency response of the leading edge 104 of
wing 102 at which the sensor 210 is located. FIG. 7 illustrates
examples of empirically derived frequency response curves for
various thicknesses of ice on the leading edge 104 of wing 102.
Alongside each frequency response curve of FIG. 7 is an indication,
as an example, of the ice thickness represented thereby.
[0054] The controller 220 extracts the frequency at which the
leading edge 104 is at resonance and, based on this frequency,
calculates the amount of ice 106 present on the leading edge 104.
Additionally, based on prior calibration, the controller 220 makes
a determination as to whether the ice 106 present on the leading
edge 104 has at least a predetermined minimum thickness, typically
2 mm. If so, the controller 220 then employs a look-up table which
indicates, for the thickness of ice 106 present on the leading edge
104, a desired vibration amplitude that should be applied to the
leading edge 104 to break the ice 106.
[0055] Prior to operating motors 110, the controller 220 calculates
the desired frequency of vibration corresponding to the desired
vibration amplitude and makes a determination of whether, once the
ice 106 is removed, the vibration amplitude will increase or
decrease.
[0056] In accordance with one embodiment of the invention, only if
at the desired frequency of vibration corresponding to the desired
vibration amplitude, the vibration amplitude will decrease once the
ice 106 is removed, are motors 110 operated to drive displacer
assemblies 116 to remove the ice 106 from the leading edges 104 of
wings 102. Otherwise, the thickness of the ice 106 will be allowed
to increase until, at the desired frequency of vibration
corresponding to the desired vibration amplitude, the vibration
amplitude will decrease once the ice 106 is removed. Alternatively
other operational techniques for preventing undesired increase in
vibration amplitude of the aircraft surface following ice
disengagement therefrom may be employed.
[0057] The functionality of FIG. 5 preferably takes place
intermittently at predetermined intervals, typically 10 minutes.
The operation of motors 110 preferably takes place upon each
actuation for a predetermined number of revolutions, typically 100
revolutions. Alternatively, the cycle of operation described
hereinabove is repeated intermittently at intervals which depend on
the altitude and flying conditions of the aircraft. Additionally or
alternatively, the cycle of operation described hereinabove is
repeated intermittently at intervals which depend on the thickness
of the ice 106 present on the leading edge 104.
[0058] If the functionality of FIG. 8, described hereinbelow, is
employed, that part of the functionality of FIG. 5 which calculates
the amount of ice present on the leading edge based on frequency is
not employed. The remainder of the functionality of FIG. 5 operates
when the functionality of FIG. 8 indicates the presence of at least
a predetermined thickness of ice 106 on the leading edge 104.
[0059] Reference is now made to FIGS. 6A and 6B, which, taken
together, are a simplified flow chart illustrating alternative
control functionality which may be employed in the alternative
embodiment of deicing system of FIGS. 1-4D when some or all of mass
180 may be selectably displaced along axis 231 such that effective
distance of the mass 180 from axis 182 may be varied.
[0060] As seen in FIGS. 6A and 6B, and similarly to the
functionality of FIG. 5, a control signal is preferably supplied by
controller 220 to motors 212, causing the motors 212 to accelerate
from rest to 500 revolutions/second. Acceleration sensors 210
measure acceleration and provide corresponding output indications
to controller 220. Controller 220 calculates vibration amplitude
vs. rate of rotation, which represents the frequency response of
the leading edge 104 of wing 102 at which the sensor 210 is
located.
[0061] The controller 220 extracts the frequency at which the
leading edge 104 is at resonance and, based on this frequency,
calculates the amount of ice 106 present on the leading edge 104.
Additionally, based on prior calibration, the controller 220 makes
a determination as to whether the ice 106 present on the leading
edge 104 has at least a predetermined minimum thickness, typically
2 mm. If so, the controller 220 then employs a look-up table which
indicates, for the thickness of ice 106 present on the leading edge
104, a desired vibration amplitude that should be applied to the
leading edge 104 to break the ice 106.
[0062] Prior to operating motors 110, the controller 220 calculates
the desired frequency of vibration corresponding to the desired
vibration amplitude and makes a determination of whether, once the
ice 106 is removed, the vibration amplitude will increase or
decrease. Only if at the desired frequency of vibration
corresponding to the desired vibration amplitude, the vibration
amplitude will decrease once the ice 106 is removed, are motors 110
operated to drive displacer assemblies 116 to remove the ice 106
from the leading edges 104 of wings 102.
[0063] At this stage, as distinguished from the functionality of
FIG. 5, the eccentric mass 180 is positioned along axis 231 so as
to be close to axis 182 such that the force applied by rotation of
mass 180 is minimized until such time as the rotational frequency
of motor 110 reached the desired frequency. Once the rotational
frequency of motor 110 reaches the desired frequency, the eccentric
mass 180 is displaced outwardly along axis 231 so as to increase
the force applied by rotation thereof about axis 182.
[0064] The functionality of FIGS. 6A and 6B preferably takes place
intermittently at predetermined intervals, typically 10 minutes.
Alternatively the cycle of operation described hereinabove is
repeated intermittently at intervals which depend on the altitude
and other flying conditions of the aircraft. Additionally or
alternatively, the cycle of operation described hereinabove is
repeated intermittently at intervals which depend on the thickness
of the ice 106 present on the leading edge 104.
[0065] The operation of motors 110 preferably takes place upon each
actuation for a predetermined number of revolutions, typically 100
revolutions. Furthermore, once motors 110 are deactuated, the
eccentric mass 180 is immediately displaced along axis 231 so as to
be close to axis 182 so as to immediately minimize the force
applied by rotation thereof as motors 110 decelerate to rest.
[0066] Reference is now made to FIG. 8, which is a simplified flow
chart illustrating control functionality employed in the deicing
system of FIGS. 1-4D particularly using acceleration sensors 310
and/or strain gages 320. As seen in FIG. 8, a control signal is
preferably supplied by controller 330 to motors 110, causing the
motors 110 to rotate at 60 revolutions/second. Acceleration sensors
310 measure acceleration of the leading edge in a direction
perpendicular thereto and/or strain gages 320 measure the strain of
the leading edge 390 in the plane illustrated in sections A-A in
FIGS. 3A-3D and provide corresponding output indications to
controller 330. Controller 330 calculates ratio of the applied
radial eccentric force to the displacement of the leading edge 390
and any ice formed thereon, which represents the stiffness of the
leading edge 390 of wing 102 adjacent which acceleration sensors
310 and/or strain gages 320 are is located together with any ice
106 formed thereon. This provides an indication of the presence and
thickness of ice 106 on the leading edge 104.
[0067] Additionally, based on prior calibration, the controller 330
makes a determination as to whether the ice 106 present on the
leading edge 104 has at least a predetermined minimum thickness,
typically 2 mm. If so, controller 220, as described hereinabove
with reference to FIG. 5, then indicates a desired vibration
amplitude that should be applied to the leading edge 104 to remove
the ice 106.
[0068] The functionality of FIG. 8 preferably takes place
intermittently at predetermined intervals, typically 1-10 minutes.
Alternatively, the cycle of operation described hereinabove is
repeated intermittently at intervals which depend on the altitude
and flying conditions of the aircraft. Additionally or
alternatively, the cycle of operation described hereinabove is
repeated intermittently at intervals which depend on the thickness
of the ice 106 present on the leading edge 104.
[0069] Reference is now made to FIG. 9, which is a simplified
illustration of an aircraft including a deicing system constructed
and operative in accordance with another preferred embodiment of
the present invention and to FIG. 10, which is a simplified
exploded view illustration of part of another preferred embodiment
of a deicing system suitable for use in the aircraft of FIG. 9.
[0070] As seen in FIG. 9, there is provided an aircraft 500
equipped with a deicing system constructed and operative in
accordance with a preferred embodiment of the present invention.
The deicing system is preferably located within the wings 502 of
the aircraft adjacent the leading edges 504 of the wings 502. The
deicing system may alternatively or additionally be located within
the tail or stabilizers of the aircraft.
[0071] It is a particular feature of the present invention that the
deicing system includes at least one motor operative to drive at
least one eccentric mass in rotational motion and at least one
displacer coupled to at least one location on at least one aircraft
surface, preferably the leading edge 504 of a wing 502, and coupled
to the at least one eccentric mass such that forces produced by the
rotational motion of the eccentric mass are applied to the at least
one displacer, causing the at least one displacer to displace the
at least one aircraft surface in a plurality of directions at each
of the at least one location, thereby causing disengagement of ice
506 from the at least one aircraft surface.
[0072] In the illustrated embodiment, a motor 510, preferably an
electric motor and alternatively a fluid driven motor, such as a
pneumatic motor, is disposed interiorly of each wing 502 adjacent
the leading edge 504 thereof and preferably alongside the aircraft
fuselage 512. A drive shaft 514 couples each motor 510, such as a
model A30-16M motor, commercially available from Hacker Brushless,
2122 West 5.sup.th Place, Tempe, Ariz. 85281, USA, to a
corresponding displacer assembly 516. It is appreciated that
multiple motors 510 and multiple drive shafts 514 are preferably
each coupled to a corresponding displacer assembly 516 at various
locations within each wing.
[0073] Turning now particularly to FIG. 10, it is seen that each
drive shaft 514 includes a flattened portion 522 generally central
thereof.
[0074] A pair of ball bearings 550 and 552, such as Model 34-5,
commercially available from Schaeffer Group--FAG GmbH of
Industriestrasse 1-3, Herzogenaurach 91074, Germany, are pressure
fit mounted onto drive shaft 514 on respective opposite sides of
flattened portion 522. A leading edge attachment element 560 is
mounted onto drive shaft portion 514 via ball bearings 550 and 552
which engage respective bearing receiving apertures 562 and 563
formed in respective arms 564 and 565 and are fixed thereto by
respective lock washers 566 and 567 and wave spring washers 568 and
569.
[0075] Leading edge attachment element 560 includes a leading edge
attachment portion 570, preferably integrally formed with radially
extending pairs of arms 564 and 565 each joined by a radially
extending generally planar portion 571 and having a curved interior
leading edge attachment surface 572 which is fixedly adhered, as by
an adhesive, such as product no. 4132 Structural Adhesive Kit,
commercially available from 3M, St. Paul, Minn. 55144, USA, to a
correspondingly curved interior surface of leading edge 504 of wing
502.
[0076] An eccentric drive mass 580 is preferably fixedly mounted to
drive shaft 514 for rotation together therewith about an axis 582.
The eccentric drive mass 580 is preferably fixedly mounted to drive
shaft 514 at flattened portion 522 by means of a pair of suitably
configured bracket elements 584 and 586 having respective facing
recesses 588 and 590, having cross sectional configurations which
respectively match the cross sectional configuration of the drive
shaft 514 at flattened portion 522. Respective ends 592 and 594 of
bracket elements 584 and 586 are retained within a suitable socket
596 of eccentric drive mass 580 by means of a retaining pin
598.
[0077] Preferably bracket elements 584 and 586 are held in place by
a pair of screws 600 and corresponding nuts 602, washers 604 and
lock washers 606.
[0078] An acceleration sensor 610, such as a model NMA 1213D
commercially available from Freescale Semiconductors Inc., 6501
William Cannon Drive West, Austin, Tex. 78735, USA, is preferably
mounted on at least one displacer assembly 516 on each wing of the
aircraft in order to serve as an ice thickness sensor, as is
described hereinbelow. A variable speed motor 612, having a mass
614 eccentrically mounted on an output shaft 616 thereof, is
mounted on the same displacer assembly 516. Alternatively, the
functionality of motor 612 may be provided by motor 510, when
operated at a relatively low frequency, typically 20 Hz.
[0079] A deicer controller 620 preferably receives inputs from
acceleration sensors 610 associated with various displacer
assemblies 516 and provides control inputs to motors 510. The
control logic preferably employed by deicer controller 620 is
described hereinabove with reference to FIG. 5 and FIG. 8 as
described hereinabove.
[0080] According to an alternative embodiment of the present
invention, an example of which is illustrated in an enlargement 630
in FIG. 10, some or all of mass 580 may be selectably displaced
along an axis 631, generally perpendicular to axis 582, such that
the effective distance of the mass 580 from axis 582 may be varied.
This provides an additional degree of freedom in controlling the
operation of the deicing system of the present invention. In the
illustrated embodiment shown in enlargement 630, a part 632 of mass
580 is mounted on a screw drive 634, which may be driven by a motor
636 to adjust the positioning of part 632 of mass 580 along axis
631.
[0081] Preferably additional acceleration sensors 710, such as
model NMA 1213D acceleration sensors commercially available from
Freescale Semiconductors Inc., 6501 William Cannon Drive West,
Austin, Tex. 78735, USA, are preferably mounted on portions 571 of
at least one displacer assembly 516 on each wing of the aircraft in
order to serve as ice presence sensors, as is described
hereinbelow. Acceleration sensors 710 are preferably arranged to
lie perpendicular to the surface of leading edge 504.
[0082] Additionally or alternatively to acceleration sensors 710,
strain gages 720, preferably strain gage 062AP commercially
available from Vishay Intertechnology Inc., 63 Lancaster Ave.,
Malvern Pa. 19355, USA, may be mounted onto the curved interior
surface of leading edge 504 of wing 502 on either side of curved
interior leading edge attachment surface 572. Attachment of the
strain gages 720 to the curved interior surface of leading edge 504
preferably employs an adhesive, such as M-Bond 200 Adhesive
commercially available from Vishay Intertechnology Inc., 63
Lancaster Ave., Malvern Pa. 19355, USA.
[0083] A deicer controller 730 preferably receives inputs from
acceleration sensors 710 associated with the various displacer
assemblies 516 and strain gages 720 and provides on-off control
inputs to motors 510. The control logic preferably employed by
deicer controller 730 is described hereinabove with reference to
FIG. 8.
[0084] It is appreciated that controllers 620 and 730 may be
integrated into a single controller. Reference is now made to FIGS.
11A, 11B, 11C and 11D, which illustrate four typical stages in a
rotation cycle which drives a displacer coupled to an aircraft
surface in a deicing system of the type shown in FIGS. 9 and 10,
and to FIGS. 4A, 4B, 4C and 4D, which illustrate, in exaggerated
form, deformation of an aircraft surface responsive to operation of
the deicing system of FIGS. 9 and 10 at stages corresponding to
those shown in FIGS. 11A, 11B, 11C and 11D respectively.
[0085] As seen in FIG. 11A, an eccentric drive mass 780 of
displacer assembly 782 is located along an axis 784 which passes
through axis 582 (FIG. 10) and extends generally perpendicular to
the plane defined by the tangent 786 to the curved surface 788 of a
leading edge 790 to which curved interior leading edge attachment
surface 792 of displacer assembly 782 is attached. Inasmuch as mass
780 lies beyond axis 582 with respect to surface 788, the displacer
assembly 782 is applying a pull force to the leading edge 790 along
axis 784.
[0086] As also seen in FIG. 11A, eccentric drive mass 800 of
displacer assembly 802 is located along an axis 804 which passes
through axis 582 (FIG. 10) and extends generally parallel to the
plane defined by the tangent 806 to the curved surface 808 of
leading edge 790 to which curved interior leading edge attachment
surface 812 of displacer assembly 802 is attached. Inasmuch as mass
800 lies along an axis which is not perpendicular to surface 808,
the displacer assembly 802 is applying a bending force to the
leading edge 790.
[0087] FIG. 4A shows, in an exaggerated manner, the deformation of
the leading edge 790 corresponding to the operational state
illustrated in FIG. 11A. The extent of exaggeration is estimated to
be a factor of 40.
[0088] In FIG. 11B, eccentric masses 780 and 800 have been rotated
from the position seen in FIG. 11A. As seen in FIG. 11B, eccentric
drive mass 780 of displacer assembly 782 is not located along axis
784. Inasmuch as mass 780 lies along an axis which is not
perpendicular to surface 788, the displacer assembly 782 is
applying a bending force to the leading edge 790. As also seen in
FIG. 11B, eccentric drive mass 800 of displacer assembly 802 is not
located along an axis 804 but is nearly perpendicular to axis 804.
Inasmuch as mass 800 lies between axis 582 and surface 806, the
displacer assembly 802 is applying a push force to the leading edge
790.
[0089] FIG. 4B shows, in an exaggerated manner the deformation of
the leading edge 790 corresponding to the operational state
illustrated in FIG. 11B. The extent of exaggeration is estimated to
be a factor of 40.
[0090] In FIG. 11C, eccentric masses 780 and 800 have been rotated
approximately 180.degree. from the position seen in FIG. 11A. As
seen in FIG. 11C, eccentric drive mass 780 of displacer assembly
782 is located along axis 784 which passes through axis 582 (FIG.
10) and extends generally perpendicular to the plane defined by
tangent 786 to curved surface 788. Inasmuch as mass 780 lies
between axis 582 and surface 788, the displacer assembly 782 is
applying a push force to the leading edge 790 along axis 784.
[0091] As also seen in FIG. 11C, eccentric drive mass 800 of
displacer assembly 802 is located along axis 804 which passes
through axis 582 (FIG. 10) and extends generally parallel to the
plane defined by tangent 806 to curved surface 808. Inasmuch as
mass 800 lies along an axis which is not perpendicular to surface
808, the displacer assembly 802 is applying a bending force to the
leading edge 790.
[0092] FIG. 4C shows, in an exaggerated manner the deformation of
the leading edge 790 corresponding to the operational state
illustrated in FIG. 11C. The extent of exaggeration is estimated to
be a factor of 40.
[0093] In FIG. 11D, eccentric masses 780 and 800 have been rotated
further counterclockwise, as seen from the perspective of the
sectional illustration shown along lines A-A therein, from the
position seen in FIG. 11A. As seen in FIG. 11D, eccentric drive
mass 780 of displacer assembly 782 is not located along axis 784.
Inasmuch as mass 780 lies along an axis which is not perpendicular
to surface 788, the displacer assembly 782 is applying a bending
force to the leading edge 790.
[0094] As also seen in FIG. 11D, eccentric drive mass 800 of
displacer assembly 802 is not located along an axis 804 but is
nearly perpendicular to axis 804. Inasmuch as mass 800 lies beyond
axis 582 with respect to surface 806, the displacer assembly 802 is
applying a pull force to the leading edge 790.
[0095] FIG. 4D shows, in an exaggerated manner the deformation of
the leading edge 790 corresponding to the operational state
illustrated in FIG. 11D. The extent of exaggeration is estimated to
be a factor of 40.
[0096] It is appreciated that axis 582 may be oriented at any
suitable orientation with respect to an aircraft surface to be
deiced and need not be generally parallel thereto as illustrated in
the examples.
[0097] Reference is now made to FIGS. 12A, 12B, 12C and 12D, which
are simplified illustrations, in exaggerated form, of deformation
of an aircraft surface responsive to synchronized operation of
multiple separate motor driven displacers of the type illustrated
in the deicing system of FIGS. 9-11D in accordance with another
preferred embodiment of the present invention.
[0098] As seen in FIGS. 12A-12D, multiple motor driven displacers
driven by multiple motors may be operated in a predetermined
sequence, typically at synchronized time intervals, to provide
deformation of an aircraft surface and disengagement of ice from
the aircraft surface. In the illustrated embodiment seen in FIGS.
12A-12D, the predetermined sequence produces displacement of the
aircraft surface which proceeds therealong in a wavelike
progression. It is appreciated that the operation of the multiple
motors may be controlled by a centralized controller to provide the
predetermined sequence. Additionally or alternatively, each of the
multiple motors may have an associated controller, where the
multiple controllers are in communication with one another or in
communication with a centralized controller.
[0099] It will be appreciated by persons skilled in the art that
the present invention is not limited by what has been particularly
shown and described hereinabove. Rather the present invention
includes both combinations and subcombinations of various features
described herein and improvements and variations which would occur
to persons skilled in the art upon reading the foregoing
description and which are not in the prior art.
* * * * *