U.S. patent application number 14/220461 was filed with the patent office on 2015-02-19 for buoyant target with laser reflectivity.
The applicant listed for this patent is American Pacific Plastic Fabricators, Inc.. Invention is credited to Arthur Anton Hochschild, III, Arthur Anton Hochschild, IV, Roman Horeczko.
Application Number | 20150048572 14/220461 |
Document ID | / |
Family ID | 52466293 |
Filed Date | 2015-02-19 |
United States Patent
Application |
20150048572 |
Kind Code |
A1 |
Hochschild, III; Arthur Anton ;
et al. |
February 19, 2015 |
BUOYANT TARGET WITH LASER REFLECTIVITY
Abstract
A buoyant target or ship decoy comprises an inflatable structure
with a drogue chute attached to the periphery of the bottom of the
inflatable structure. The drogue chute is an open flexible
structure with a bottom end weighted with ballast to deploy it, and
with ports through its side to permit water to flow into and out of
it. A laser reflector member is attached to an exterior surface of
the inflatable structure. The laser reflector member comprises a
body having one or more laser reflective surfaces.
Inventors: |
Hochschild, III; Arthur Anton;
(Huntington Beach, CA) ; Horeczko; Roman;
(Huntington Beach, CA) ; Hochschild, IV; Arthur
Anton; (Anaheim, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
American Pacific Plastic Fabricators, Inc. |
Garden Grove |
CA |
US |
|
|
Family ID: |
52466293 |
Appl. No.: |
14/220461 |
Filed: |
March 20, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61806794 |
Mar 29, 2013 |
|
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|
Current U.S.
Class: |
273/350 |
Current CPC
Class: |
F41J 2/00 20130101 |
Class at
Publication: |
273/350 |
International
Class: |
F41J 2/00 20060101
F41J002/00 |
Claims
1. A buoyant target comprising: an inflatable structure formed of a
flexible material that allows the inflatable structure to expand
from a collapsed state to an inflated state; and a laser reflector
member disposed on an exterior surface of the inflatable structure,
the laser reflector member comprising at least one laser reflective
surface.
2. The buoyant target of claim 1, wherein the laser reflector
member is a laser reflective tape.
3. The buoyant target of claim 2, wherein the laser reflective tape
is disposed on a top panel or along an upper portion of a sidewall
panel of the inflatable structure.
4. The buoyant target of claim 1, wherein the laser reflector
member is a body attached to the inflatable structure, the body
having at least one laser reflective surface.
5. The buoyant target of claim 4, wherein the body is disposed on a
top panel or along an upper portion of a sidewall panel of the
inflatable structure.
6. The buoyant target of claim 4, wherein the body comprises a
prism or body having a plurality of planar, laser reflecting
surfaces.
7. The buoyant target of claim 5, wherein the body is one of an
octagonal, hexagonal, cubic or pyramidal body.
8. The buoyant target of claim 1, wherein the member has a
plurality of laser reflective surfaces, each surface reflecting in
a direction different from that of the other laser reflective
surfaces.
9. The buoyant target of claim 1, wherein the member is disposed on
a top panel, or one or more upper portions of a sidewall panel of
the inflatable structure.
10. The buoyant target of claim 9, wherein the inflatable structure
has at least four sidewall panels and the member is disposed on
upper portions of all the sidewall panels.
11. The buoyant target of claim 1, further comprising a stabilizing
structure connected to a bottom end of the inflatable structure,
the stabilizing structure enclosing a chamber and including an
aperture that allows water to fill the chamber when the target is
placed on water.
12. The buoyant target of claim 1, further comprising a radar
reflector device disposed inside the inflatable structure, the
radar reflector device comprising a plurality of 3-surface
orthogonal reflectors configured to reflect a radar signal.
13. The buoyant target of claim 12, wherein the radar reflector
device comprises three flat sheets that are substantially
perpendicular to each other, and the three flat sheets form the
plurality of 3-surface orthogonal reflectors.
14. The buoyant target of claim 12, wherein each of the 3-surface
orthogonal reflectors has a central reflection vector oriented at
substantially equal angles from each radar reflective surface of
the 3-surface orthogonal reflector, and the central reflection
vectors point radially outward, in plan view, from the inflatable
structure.
15. The buoyant target of claim 14, wherein the central reflection
vectors are spaced apart from each other, in plan view, at
substantially equal angles.
16. The buoyant target of claim 14, wherein the radar reflector
device comprises six 3-surface orthogonal reflectors, and the
corresponding six central reflection vectors are spaced apart from
each other, in plan view, at angles from about 50 degrees to about
70 degrees.
17. The buoyant target of claim 1, further including a radar
reflector device disposed within the inflatable structure, the
radar reflector device comprising three mutually orthogonal and
intersecting planes, the planes configured to reflect a radar
signal, the planes forming a plurality of orthogonal
reflectors.
18. The buoyant target of claim 17, wherein each plane is bounded
by an edge that forms a circle, and the edge of each plane abuts an
interior surface of the inflatable structure, the interior surface
being substantially horizontal when the inflatable structure is in
the inflated state.
19. The buoyant target of claim 17, wherein the planes form eight
3-surface orthogonal reflectors each having a central reflection
vector, and wherein when the inflatable structure is in the
inflated state, a first three of the central reflector vectors are
tilted above horizontal at substantially equal angles of at least
10 degrees and a second three of the central reflector vectors are
tilted below horizontal at substantially equal angles of at least
10 degrees.
20. The buoyant target of claim 17, wherein the radar reflector
device comprises a plurality of reflective leaves configured to
pivot or bend relative to each other, the reflective leaves forming
at least one of the three mutually orthogonal and intersecting
planes.
21. The buoyant target of claim 4, wherein the body comprises at
least 12 laser reflective surfaces.
22. The buoyant target of claim 21, wherein the body comprises a
12-sided prism.
23. The buoyant target of claim 4, wherein the body is positioned
on the buoyant target such that the buoyant target is capable of
reflecting laser light incident from angles separated by 30 degrees
relative to a center of the buoyant target.
24. The buoyant target of claim 22, further comprising a plurality
of the 12-sided prisms, wherein each is oriented about its main
axis relative to the others so that the buoyant target is capable
of reflecting laser light incident from angles separated by less
than 30 degrees.
25. A ship decoy comprising: an inflatable structure formed of a
flexible material that allows the inflatable structure to expand
from a collapsed state to an inflated state; and a laser reflector
member disposed on an exterior surface of the inflatable structure,
the laser reflector member comprising at least one laser reflective
surface.
26. The ship decoy of claim 25, further comprising means for
automatically deploying the decoy.
27. The ship decoy of claim 25, wherein the decoy is in a stowed
configuration, further including an inflation source sealed via a
closed valve, the inflation source comprising a compressed fluid
and being coupled to a valve of the decoy for inflating the decoy,
and at least one lanyard for opening the closed valve to thereby
cause rapid inflation of the decoy via the inflation source.
28. A ship decoy system further comprising a plurality of stowed
decoys according to claim 25, further including an inflation source
sealed via a closed valve, the inflation source comprising a
compressed fluid and being coupled via a fluid conduit or tubing to
valves of each of the decoys for inflating each of the decoys via
the inflation source, and at least one lanyard for remotely opening
the closed valve to thereby cause rapid inflation of the decoys via
the inflation source.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/806,794, filed Mar. 29, 2013, which is
incorporated herein by reference it its entirety.
FIELD OF THE INVENTION
[0002] This invention relates generally to a target for gunfire
training and, more particularly, to a buoyant, inflatable target
with laser reflectivity. The invention is optionally used for "man
overboard" training exercises.
BACKGROUND OF THE INVENTION
[0003] Naval battle exercises involve shipborne weapons and
floating targets to be hit by gunfire. It is often desired that the
targets simulate the size and/or movement of boats and other
floating objects. A problem associated with such targets is that
they must often be large in size, which makes providing a large
number of "hard targets" impractical. To address this, it is common
practice to provide buoyant, inflatable and collapsible structures
for targets. Such targets can be folded to a relatively small size
so that many can be stored and quickly inflated to full size on the
water.
[0004] Buoyant and inflatable targets, however, are susceptible
water currents and waves, and more particularly to the wind, also
known as set and drift, which cause the targets to move in a manner
that does not properly simulate movements of a true battle target.
Anchors or drogue chutes are often added to the targets to prevent
or inhibit excessive movement. Many conventional drogue chutes
cannot be emptied to permit convenient target recovery. Proper sea
anchors take time and experience to rig and launch, and the anchor
line and commercial sea anchors cost money. Many times a makeshift
sea anchor is improperly rigged using a weighted ammunition shell
casing or ammunition box full of scrap metal. These types of sea
anchors drop directly below the target balloon and exert too much
resistance in heavy seas, resulting in damage to the target balloon
before it can serve its intended purpose.
[0005] Increasingly, gunnery exercises involve the use of laser
and/or radar to sight in gunnery and missile guidance systems,
thereby raising the need for an inflatable target with enhanced
laser and/or radar reflectivity. With regard to radar reflectivity,
prior attempts to increase radar reflectivity included mixing metal
shavings with a viscous liquid, such as oil, and pouring the
mixture inside the inflated target. A problem with this approach is
that the metal shavings can provide insufficient reflectivity,
especially when the shavings settle to the bottom of the target
over time. Metallic sheet materials have also been attached on the
exterior of an inflatable target to increase radar reflectivity. A
problem with this approach is that the metallic material, due to
its electrical conductive properties, could present an electrical
hazard during deployment and/or retrieval of the target on the deck
of a ship. Other approaches involving metal plates have the
disadvantage of puncturing the inflatable target and making the
target top heavy or unwieldy during deployment and retrieval of the
target.
[0006] Laser reflective targets can be used to sight in and
reconcile the accuracy of a ship's missile and gunfire laser
guidance systems. Accuracy must be validated to insure that
calibration is correct. To do this, one needs to fire weapons using
the laser guidance system.
[0007] Accordingly, there is a continuing need for an inflatable
floating target that closely simulates the movement of a body of
substantial mass and stability so as to establish a more accurate
test of a trainee's gunnery skills, maintains a generally upright
orientation, and which has enhanced laser and/or radar
reflectivity.
SUMMARY OF THE INVENTION
[0008] Briefly and in general terms, the present invention is
directed to a buoyant target with laser reflectivity.
[0009] In aspects of the present invention, a target comprises an
inflatable structure formed of a flexible material that allows the
inflatable structure to expand from a collapsed state to an
inflated state.
[0010] The target further comprises one or more laser reflector
members disposed on one or more exterior surfaces of the inflatable
structure, each one of the one or more laser reflector members
comprising one or more laser-reflective surface configured to
reflect laser light, e.g., infrared laser light.
[0011] In other aspects, a target comprises an inflatable structure
formed of a flexible material that allows the inflatable structure
to expand from a collapsed state to an inflated state. The target
further comprises, in combination, a radar reflector device
disposed inside the inflatable structure, the radar reflector
device comprising a plurality of 3-surface orthogonal reflectors
configured to reflect a radar signal, and one or more laser
reflector members disposed on one or more exterior surfaces of the
inflatable structure, each one of the one or more laser reflector
members comprising one or more laser-reflective surfaces configured
to reflect laser light, e.g., infrared laser light.
[0012] In other aspects, a target comprises an inflatable structure
configured to expand from a collapsed state to an inflated state
when filled with gas. The target further comprises, in combination,
a radar reflector device disposed within the inflatable structure,
the radar reflector device comprising three mutually orthogonal and
intersecting planes, the planes configured to reflect a radar
signal, the planes forming a plurality of orthogonal reflectors.
And one or more laser reflector members disposed on one or more
exterior surface of the inflatable structure, each one of the one
or more laser reflector members comprising one or more
laser-reflective surface configured to reflect laser light, e.g.,
infrared laser light.
[0013] The features and advantages of the invention will be more
readily understood from the following detailed description which
should be read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a front elevation of a buoyant target in its
deployed configuration, showing a partial cutaway view near the
bottom and the top of the target, wherein the side and rear
elevations are identical;
[0015] FIG. 2 is a bottom view taken at line 2-2 in FIG. 1, showing
four apertures for allowing water to fill a drogue chute attached
to a bottom end of the buoyant target;
[0016] FIG. 3 is a top view taken at line 3-3 in FIG. 1, showing a
top panel connected above front, rear, left and right panels;
[0017] FIG. 4 is a front elevation view of the inflatable target of
FIG. 1, showing a partial cutaway revealing a radar reflector
device attached by securement lines to interior surfaces of the
buoyant target;
[0018] FIG. 5 is a perspective view of the radar reflector device
of FIG. 4, showing eight 3-surface orthogonal reflectors formed by
three mutually orthogonal and intersecting planes;
[0019] FIG. 6 is a perspective view of the radar reflector device
of FIG. 4, showing three substantially planar surfaces, illustrated
in solid line, of one of the eight 3-surface orthogonal
reflectors;
[0020] FIG. 7 is a cutaway, perspective view of a top panel of a
buoyant target, showing a means for attaching a spherical radar
reflector device to the target, the radar reflector being loosely
connected to an interior surface of the buoyant target;
[0021] FIG. 8 is an elevation view of the top panel and buoyant
target of FIG. 7, showing the means for attaching in a tightened
state so that edges of the spherical radar reflector device are
pulled into contact with the interior surface of the buoyant
target;
[0022] FIG. 9 is a top view of the spherical radar reflector device
of FIG. 8, showing central reflection vectors, in plan view, spaced
apart from each other at substantially equal angles;
[0023] FIG. 10 is a perspective view of a folding radar reflector
device in a partially unfolded state, showing movable flat
reflective leaves attached to a flat reflective base;
[0024] FIG. 11 is a perspective view of the folding radar reflector
device of FIG. 10 in a further unfolded state, showing increased
tension placed on securement lines attached to the reflective
leaves;
[0025] FIG. 12 is a cutaway, elevation view of a buoyant target,
showing the folding radar reflector device of FIGS. 10 and 11 with
the reflective leaves and the reflective base forming three
mutually orthogonal planes;
[0026] FIG. 13 is an elevation view of a buoyant target, showing an
electronic device configured to transmit signals;
[0027] FIG. 14 is a front elevation of the buoyant target of FIG.
1, showing the placement of one or more laser reflector members on
one or more exterior surfaces of the target; and
[0028] FIGS. 15A-15D illustrate four embodiments of the laser
reflector member in FIG. 14.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Referring now in more detail to the exemplary drawings for
purposes of illustrating embodiments of the invention, wherein like
reference numerals designate corresponding or like elements among
the several views, there is shown in FIGS. 1-4 a buoyant target 10
made of a flexible membrane material so it can be collapsed and
folded to a small bulk. Part of the buoyant target 10 can be
inflated for deployment on water. The membrane material is
impermeable to the inflating gas. Suitable materials include
without limitation polyvinyl chloride and polyethylene sheeting,
which are preferable because structural seams can be heat sealed,
solvent sealed, or cemented as desired.
[0030] The buoyant target 10 has an inflatable structure 11 that
comprises a top panel 12, a bottom panel 13 and a sidewall 14 which
enclose an air-filled chamber 16 upon deployment. The inflatable
structure is substantially airtight. The sidewall 14 is rectangular
and has a front panel 14a, a right panel 14b, a rear panel 14c, and
a left panel 14d. Instead of being rectangular, the sidewall can be
circular in other embodiments.
[0031] As shown in FIG. 1, a valve 15 in one of the sidewall panels
is provided to enable the inflatable structure 11 to be inflated or
deflated as needed. A drogue chute 20 is attached to the bottom
panel 13 of the inflatable structure 11, which stabilizes the
inflatable structure and prevents the it from tipping over of
tilting excessively due to wave motion and wind. An upper edge 21
of the drogue chute preferably conforms to and is attached to the
perimeter of the sidewall 14 and bottom panel 13. The drogue chute
20 is a flexible structure formed from material identical to or
similar to that of the inflatable structure to allow the drogue
chute to be folded for storage, and unfolded when the buoyant
target is deployed.
[0032] Still referring to FIG. 1, the deployed drogue chute 20 is
preferably tapered. The deployed drogue chute 20 comprises a
tapered sidewall 22 that converges toward a lower end 23. The lower
end 23 is aligned with the central axis 40 of the inflatable
structure 11. The central axis 40 is located at substantially equal
distances from the front panel 14a, the right panel 14b, the rear
panel 14c, and the left panel 14d of the sidewall. The tapered
sidewall 22 of the drogue chute 20 is pyramidal. Other tapered
shapes for the sidewall 22 are possible, including without
limitation a conical shape.
[0033] The tapered sidewall 22 and the bottom panel 13 of the
inflatable structure 11 enclose a chamber 25 which fills with water
upon deployment of the buoyant target 10. A plurality of apertures
or ports 24 are formed through the tapered sidewall 22 of the
drogue chute 20. The ports 24 are of sufficient diameter to permit
some flow of water into and out of the chamber 25, but small enough
to leave a sufficient area of material of the tapered sidewall 22
to engage water within the drogue chute chamber 25. The water
within the drogue chute chamber 25 serves to stabilize the
inflatable structure 11 above.
[0034] A weight 30 is fixed to the lower end 23 of the drogue chute
20. When the inflatable structure 11 is inflated and placed on
water, the weight 30 will pull the drogue chute down to the pyramid
shape. The chute will fill with water quickly, will stabilize the
buoyant target so it rests upright in the water, and will resist
movement by the wind and water current.
[0035] The drogue chute 20 functions as an anchor against drift
caused by wind on the inflatable structure 11 while simultaneously
allowing water current to pass through and/or around the drogue
chute. Unlike conventional sea anchors, which have a parachute-like
structure submerged in the water and connected by a line to a
buoyant target, the drogue chute 20 inhibits movement of the
buoyant target due to water current and wind. Another problem with
conventional sea anchors is that they can drop downwardly and
become a deadweight on the buoyant target, which might submerge the
buoyant target and/or make recovery of the buoyant target
difficult.
[0036] To facilitate recovery of the buoyant target 10, a flexible,
nylon rope or tow line 35 is optionally attached to the lower end
23 of the drogue chute 20 to allow a person to pull the lower end
upward, tilting the buoyant target, and spilling the water that was
in the drogue chute chamber 25 when the buoyant target is to be
removed from the water. The inflatable structure 11 can then be
deflated by opening the valve 15, and the fully collapsed target
can readily be pulled aboard a ship. An optional float 36 is
attached to the other end of the tow line 35. The float 36 keeps
the other end of the tow line 35 near the water surface 37 to allow
ready access to the tow line to start the process of recovering the
buoyant target.
[0037] In some embodiments, the inflatable structure 11 is a
10-foot cube, the drogue chute 20 is a 3-foot high inverted pyramid
extending upward from the lower end 23 to the bottom panel 13 of
the inflatable structure 11, and the water flow-through ports 24
are about 6 inches in diameter and located on all four sides of the
drogue chute pyramid. It will be appreciated that other dimensions
may be implemented as desired to simulate a variety of battle
targets.
[0038] In a preferred embodiment, the buoyant target 10 when
inflated has a height of about 14feet. On a calm lake the horizon
is 15 miles away viewed from a height of 6 feet. Placement of the
laser and/or radar reflectors high off the water is desirable
because in addition to the curvature of the earth, rough sea states
reduce visibility, making a reflector height critical.
[0039] As shown in FIG. 14, a laser reflector member 200 is
disposed on the top panel 12 of the buoyant target 10.
Alternatively, a laser reflective member 201 can be disposed on one
or more exterior surfaces of the sidewall panels 14a, 14b, 14c or
14d. For example, the laser reflector member 201 may be disposed on
all four sidewall panels 14a-14d as well as member 200 on the top
panel 12, or on one, two or three of sidewalls 14. The member 200
and/or member 201 can be the same or different from each other,
e.g., laser reflective tape on upper portion(s) of sidewalls 14 and
a multi-sided body with laser reflective surfaces on top panel 12.
Or member 201 can be disposed on the four sidewalls 14a-14d but not
the top panel 12. For embodiments where a laser reflector member
200/201 is disposed on a sidewall 14, the reflector 200/201 is
located on an upper sidewall or nearest the top panel 12 so that
the reflector member 200/201 is visible over greater distances,
especially in rough seas. The same positioning relative to the
upper panel 12 may apply for the radar reflector, described
below.
[0040] The laser reflector member 200 may correspond to a laser
reflective material, covering, or laminate directly attached to, or
formed integrally with material that forms the buoyant target
panels. The reflective material may be a laser reflective tape
secured to the exterior surface of the panels 12 and/or 14 or a
laser reflective strip of material attached to, or covering a rigid
foam shape, e.g., hexagonal or octagonal block, or other durable,
light weight body. The body is attached or adhered to exterior
surfaces of the panel 12 and/or upper portion of sidewall panels 14
using hook and loop fasteners, snaps, wire ties, adhesive, or
straps. The laser reflective member 200 or 201 can be in the form
of a prism with reflective exterior surfaces, such as any of prisms
220, 222, 224, and 226 described below.
[0041] FIGS. 15A-15C illustrate three possible shapes for a body
attachable to top or sidewall panel and having a laser reflective
surface. The bodies are formed of a light weight and durable
material and can be easily attached to exterior surfaces of the
buoyant target 10. FIG. 15A shows an octagonal prism 220 having one
or more laser reflective surfaces 220a. FIGS. 15B and 15C show a
square or rectangular pyramidal block 222 and a rectangular or
cubic block 224, each having one or more laser reflective surface
222a and 224a, respectively. In other embodiments the laser
reflector member 200 may take the shape of a rectangular prism,
triangular prism, hexagonal prism, square pyramid (FIG. 15C),
triangular pyramid, hexagonal pyramid. In some embodiments, every
surface of the prism 220, 222, 224, or 226 is laser reflective.
[0042] Referring to FIG. 15D, according to another embodiment a
laser reflector member is a 12-sided prism 226 having a laser
reflective surface 226a on each of the 12 sides. The prism has a
diameter d that can be up to the length or width of the top panel
12 of the buoyant target 10. The 12-sided body illustrated in FIG.
15D reflects laser light from up to a 30 degree angle, which
corresponds to the angle theta subtended (as shown in FIG.
15D).
[0043] In some embodiments a plurality of multiple-sided bodies,
e.g., the bodies shown in FIGS. 15A-15D or listed above, are
disposed on the top panel 12 and rotationally oriented relative to
each-other such that the buoyant target becomes capable of
increasing its laser reflectivity for light incident from different
directions. For example, for the 12-sided body, if two bodies 226
are placed on the top panel 12 and positioned relative to each
other so that one is rotated 15 degrees about axis 228 (FIG. 15D)
relative to the other, then the combined bodies 226 can reflect
laser light incident from twice the number of directions as when
only prism is used, i.e., 24 different directions with two 12-sided
prisms, verses 12 directions with only one 12-sided prism. Axis 228
is parallel to the laser reflective surfaces 226a on the side of
body 226.
[0044] The laser reflector member 200 may embody one or more
reflective surfaces. A laser reflective tape has a single
reflective surface when disposed on only one panel, e.g., extending
across the upper surface of the top panel 12 or a single sidewall
panel 14, four reflective surfaces when it is disposed around the
perimeter and along the upper portions of sidewalls 14a-14d, etc.
The octagonal body 220 can have from 1 to 9 laser reflective
surfaces when attached to a panel surface, the cubic body 224 from
1-5 reflective surfaces, etc.
[0045] As shown in FIG. 4, a radar reflector device 50 is secured
within the air-filled chamber 16 of the inflatable structure 11.
The radar reflector device is secured with a plurality securement
lines 51, which can be a rope, cable, or other flexible cord. The
other ends of the securement lines are fixed to the interior
surfaces of the inflatable structure 11. When the inflatable
structure 11 is fully inflated with gas, as shown in FIG. 4, the
securement lines are taught and align the radar reflector device
with the central axis 40 of the inflatable structure 11.
[0046] As shown in FIG. 5, the radar reflector device 50 comprises
three mutually orthogonal sheets 52 of reflective material. As used
herein, the phrase "mutually orthogonal" means that the referenced
structures are substantially perpendicular to each other. It is to
be understood that a condition modified by the word "substantially"
or "substantial" is present in absolute or perfect form, as well as
not necessarily absolute or perfect form but would be considered
close enough to those of ordinary skill in the art to warrant
designating the condition as still being present.
[0047] The sheets 52 of reflective material are substantially
planar. One of the sheets 52a is illustrated horizontal and the
other two sheets 52b, 52c are illustrated as vertical. The sheets
52 can have other orientations to facilitate reflection of a radar
signal or other electromagnetic radiation transmitted from a
particular direction relative to the buoyant target 10. The sheets
can be rigid, radar-reflective metal plates, or plates of
non-reflective material such as a plastic material or corrugated
cardboard.
[0048] Each of the sheets 52 are squares, which give the radar
reflector device 50 a cubic outline, though it will be appreciated
that the sheets 52 can have other shapes. The cubic radar reflector
device 50 comprises a total of eight groups 54a-54f of reflective
surfaces 56. Each of the eight groups 54a-54f is a quadrant that
comprises three radar reflective surfaces 56 that face each other
and are mutually orthogonal, so as to form what is referred to
herein as a 3-surface orthogonal reflector. The individual
reflective surfaces 56 can be a metallic foil, metallic paint, or
other radar reflective material that is laminated on, coated on,
bonded on, imbedded in, or covered on the sheets 52. Mylar (R) can
be used as a foil material. Optionally, the radar reflective
surfaces 56 can be covered by a fabric or layer of soft material to
prevent the radar reflector device 50 from cutting, puncturing, or
otherwise damaging the inflatable structure 11
[0049] As used herein, the phrase "3-surface orthogonal reflector"
is defined as three radar reflective surfaces that face each other
and are mutually orthogonal. For each group 54a-54f, the three
surfaces 56 are mutually orthogonal in that each surface is
substantially perpendicular to the other two surfaces of the group.
For clarity, a first of the 3-surface orthogonal reflectors 54a is
illustrated in solid line and the other 3-surface orthogonal
reflectors are illustrated in broken line in FIG. 6. In each
3-surface orthogonal reflector, the three mutually orthogonal
surfaces 56 converge or intersect at a common central point 58.
[0050] As shown in FIG. 5, each of the 3-surface orthogonal
reflectors 54a-54h has a central reflection vector 60a-60h. As used
herein, the "central reflection vector" is defined as a straight
line pointing in a particular direction. Each central reflection
vector originates from the central point 58 of the respective
3-surface orthogonal reflector. The center points of the eight
3-surface orthogonal reflectors are mutually coincident or coincide
at the overall center of the radar reflector 50. Thus, the central
reflection vectors 60a-60h point radially outward at different
directions from the center of the radar reflector device 50.
[0051] The following description in connection with FIG. 6 for the
central reflection vector 60a of the first 3-surface orthogonal
reflector 54a also applies to the respective central reflection
vectors of the other seven 3-surface orthogonal reflectors of the
radar reflector device 50.
[0052] FIG. 6 shows the three mutually orthogonal surfaces 56aa,
56ba, 56ca of one of the 3-surface orthogonal reflectors 54a. The
first planar surface 56aa is substantially perpendicular to the
other two planar surfaces 56ba, 56ca. The central reflection vector
60a is oriented at substantially equal angles a relative to each of
the three mutually orthogonal surfaces 56aa, 56ba, 56ca. That is,
the central reflection vector 60a is oriented at or about
forty-five degrees from the first planar surface 56aa, at or about
forty-five degrees from the second planar surface 56ba, and at or
about forty-five degrees from the third planar surface 56bc.
[0053] In some embodiments, some of the central reflection vectors
60 of the radar reflector device 50 are substantially horizontal
when the inflatable target 10 is fully inflated and deployed, as
shown in FIG. 5. Having at least some of the central reflection
vectors 60 substantially horizontal allows for better reflection of
electromagnetic radiation originating from ships on the water as
compared to having none of the central reflection vectors 60
substantially horizontal.
[0054] FIG. 7 shows another radar reflector device 50' for use in
the inflatable target 10. The radar reflector device 50' comprises
three mutually orthogonal sheets 52' of reflective material. The
sheets 50' are substantially planar. The radar reflector device 50'
has a spherical outline because the sheets 52' are circles.
Suitable materials and construction of the sheets 52' can be the
same as previously described above in connection with FIG. 5. The
spherical radar reflector device 50' comprises a total of eight
groups 54a'-54f of reflective surfaces 56'. Each group comprises
three mutually orthogonal surfaces that face each other so as to
form a 3-surface orthogonal reflector. In each 3-surface orthogonal
reflector, the three mutually orthogonal surfaces 56' converge or
meet at a common central point 58.'
[0055] The spherical radar reflector device 50' is attached to the
inner surface of the top panel 12 of the inflatable structure 11
and is disposed inside the air-filled chamber 16 when the buoyant
target 10 is deployed for use. The area of attachment 70 is
centered on the central axis 40 of the inflatable structure 11.
There is a circular piece of reinforcement material 72 at the area
of attachment 70. The reinforcement material 72 is bonded, welded
or adhered to the inner surface of the top panel 12. Opposite ends
of a strap 74 are bonded, welded or adhered to the bottom surface
of the reinforcement material 72. The strap 74 attaches a D-ring 76
to the inflatable structure 11. A middle segment of the strap 74
forms a loop under the reinforcement material 72 and carries the
D-ring.
[0056] An adjustable, flexible loop 78, such as thin rope, cord, or
plastic wire tie, is strung through a hole at the center of the
spherical radar reflector device 50' and through the D-ring 76. The
flexible loop 78 is fed through the center hole of the radar
reflector device in such a way that a loop segment 78a, which is
looped around the D-ring 76, extends out from a first 3-surface
orthogonal reflector 54a', and the free ends 78b, 78c extend out
from another 3-surface orthogonal reflector 54g'. A one-way device
78d at one end 78b allows the other end 78c to move in only one
direction, downward. Examples for the one-way device 78d include
without limitation a slip knot that engages the other end 78c or a
flexible ratchet device that engages rigid bumps arranged in series
on the other end 78c. When the other end 78c is pulled through the
one-way device 78d, the size of the flexible loop is reduced which
moves the spherical radar reflector device 50' upward to the D-ring
76. The flexible loop 78 passes through the central holes of a pair
of washers 80 made of rubber or elastomeric material. One washer is
above and the other is below the radar reflector device 50'. The
washers 80 prevent the flexible loop 78 from inadvertently pulling
out of engagement with the radar reflector device 50'.
[0057] In some embodiments, as shown in FIG. 8, the flexible loop
78 is tightened so that the first orthogonal reflector 54a' is
covered by the top panel 12 of the inflatable structure 11. The top
panel 12 abuts the edges of each of the three mutually orthogonal
surfaces 56aa', 56ba', 56ca' of the first orthogonal reflector
54a'. The risk of damage to the top panel 12 is minimized because
the edges of the orthogonal surfaces are rounded with no sharp
corners, unlike the cubic radar reflector device 50. Also, since
the three mutually orthogonal surfaces 56aa', 56ba', 56ca' are
substantially the same size and shape, the central reflection
vector 60a' of the first orthogonal reflector is substantially
vertical and pointed upward and is substantially coincident with
the central axis 40 of the inflatable structure 11. This ensures
that the six surrounding 3-surface orthogonal reflectors 54b',
54c', 54d', 54e', 54f', 54h' have central reflection vectors 60b',
60c', 60d', 60e', 60f', 60h' that radiate outward toward potential
radar transmitters and receivers so as to improve radar
reflectivity of the buoyant target.
[0058] FIG. 9 shows a plan view, i.e., top view, of the spherical
radar reflector device 50' of FIG. 8 which has been tightly secured
so as to abut the top, interior surface of the inflatable structure
11. In FIG. 9, the top panel 12, the flexible loop 78, and washers
80 are not shown for the sake of clarity. Six of the central
reflection vectors 60b', 60c', 60d', 60h', 60e', 60f' point outward
from the center 58' of the radar reflector device 50'. In plan
view, as shown in FIG. 9, the six central reflection vectors 60b',
60c', 60d', 60h', 60e', 60f' are separated from each other by
substantially equal angles .beta. of about sixty degrees. The
remaining two central reflection vectors 60a', 60g' are oriented
vertically and aligned with the central axis 40 of the inflatable
structure 11. In other embodiments, the angles 0 range from about
fifty degrees to about seventy degrees.
[0059] In elevation view, as shown in FIG. 8, the non-vertical
reflection vectors 60b', 60c', 60d', 60h', 60e', 60f' are tilted
from a horizontal plane H at substantially equal angles y of about
20 degrees. Three of the six non-vertical reflection vectors 60b',
60d', 60e' are tilted above the horizontal plane H. The other three
non-vertical reflection vectors 60c', 60f', 60h' are tilted below
the horizontal plane H. In some embodiments, the angles y range
from about ten degrees to about thirty degrees, and more narrowly
about fifteen degrees to about twenty-five degrees. Although none
of the central reflection vectors 60b', 60c', 60d', 60h', 60e',
60f' are substantially horizontal, Applicant has found that this
configuration of central reflection vectors--tilted from horizontal
from about twenty to thirty degrees, and more preferably about 20
degrees--provides outstanding radar reflection even when the
buoyant target 10 is bobbing and tilting side to side on the
water.
[0060] In some embodiments, the means and method for attachment
shown in FIG. 7 and described in connection with FIG. 8 are
duplicated on multiple interior surfaces of the sidewall 14 of the
inflatable structure 11, and a corresponding number of radar
reflector devices are secured thereto to provide additional radar
reflectivity to the buoyant target 10. For example, two or more of
the radar reflector devices 50' can be attached to the top panel 12
within the inflatable chamber 16 of the inflatable structure 11. In
another non-limiting example, radar reflector devices can be
secured in contact with interior surfaces of the front, rear, right
and left panels 14a, 14b, 14c, 14d of the sidewall.
[0061] In some embodiments, the means and method for attachment
shown in FIG. 7 and described in connection with FIG. 8 are
duplicated on multiple exterior surfaces of the sidewall 14 and/or
the top panel 12. For example, radar reflector devices can be
detachably secured in contact with exterior surfaces of one or any
combination of the top panel 12 and the front, rear, right and left
panels 14a, 14b, 14c, 14d of the sidewall.
[0062] FIGS. 10-12 show a folding radar reflector device 100 having
reflective surfaces 102 configured to move relative to each other.
The radar reflector device comprises a reflective base 102a, which
is illustrated as horizontal in FIGS. 10 and 11, and eight
reflective leaves 102b that attached to the reflective base 102a.
Both sides of the base 102a and each leaf 102b are radar
reflective.
[0063] Each reflective leaf 102b has a fixed edge 104 that is
hingedly connected to the reflective base. The fixed edges 104 are
substantially straight to allow the reflective leaf to easily pivot
between a face-down orientation, substantially parallel to the
reflective base, and an upright orientation, substantially
perpendicular to the plate. There are four reflective leaves 102b
on one side of the reflective base, and another four reflective
leaves on the other side of the reflective base. For each group of
four reflective leaves, the fixed edges are substantially
perpendicular to each other so as to form a cross pattern on the
reflective base.
[0064] Each reflective leaf 102b has an outer edge 106 and an inner
edge 108, both of which are free to move relative to the reflective
base. The inner edge 108 connects the outer edge 106 to the fixed
edge 104. A cord 110 is attached to each reflective leaf at or near
where the outer and inner edges meet. The individual cords for the
four reflective leaves above the reflective base meet at the end of
a first securement line 51a. The individual cords for the four
reflective leaves above the reflective base meet at the end of a
second securement line 51b. With no tension placed on the
securement lines 51a, 51b, the reflective leaves 102b are free to
collapsed to the face-down orientation onto the reflective base
102a. Tension on the securement lines 51a, 51b is produced by
pulling the two securement lines apart and away from the radar
reflector device 100. FIGS. 10 and 11 show the reflective leaves
102b pivoting relative to each other, and relative to the base
102a, as a result of different amounts of tension in the securement
lines 51a, 51b, with FIG. 10 having less tension than in FIG.
11.
[0065] As tension is increased beyond that of FIG. 11, the
reflective leaves 102b reach their fully upright orientation shown
in FIG. 12 in which they are substantially perpendicular to the
reflective base 102a. With all the reflective leaves 102b in their
fully upright orientation, the folding radar reflector device 100
has the same structural configuration as the radar reflector device
50' of FIG. 7-9. It will be appreciated that the reflective leaves
102b are capable of moving independently of each other and that
tension on the securement lines 51a, 51b causes the reflective
leaves 102b to move simultaneously to their upright
orientations.
[0066] As shown in FIG. 12, the folding radar reflector device 100
can be mounted within the air-filled chamber 16 of the inflatable
structure 11 of the buoyant target 10. The securement lines 51a,
52b are secured to inner surfaces of the inflatable structure 11 so
that inflation of the inflatable structure 11 increases tension on
the securement lines. The means and method of attachment can be the
same as that described in connection with FIG. 7.
[0067] The securement lines 51a, 52b can be sized so that when the
inflatable structure 11 is fully inflated, the reflective leaves
102b are at their fully upright orientation relative to the
reflective base 102a. In FIG. 12, the reflective base 102a is not
horizontal. The ends of the securement lines 51a, 51b are attached
to predetermined positions on the inflatable structure 11 so that
when the inflatable structure is fully inflated, the radar
reflector device 100 and its central reflection vectors have the
same orientation as described in connection with FIGS. 8 and 9. It
should also be apparent from FIG. 12 that the securement lines 51a,
51b maintain the orientation of the radar reflector device 100
while the inflatable structure 100 remains filled with gas.
[0068] Any number of the reflective leaves 102b and the reflective
base 102a can have the same construction as that described above
for the orthogonal sheets 52, 52' and the reflective surfaces 56,
56' in connection with FIGS. 4-9. In further embodiments, the
reflective base 102a and leaves 102b are constructed of a
light-weight corrugated plastic or cardboard that is laminated on
both sides with metal foil, then covered with a protective
material, such as flexible fabric. The protective material near the
fixed edges of the reflective leaves 102b are attached, such as by
stitching or bonding, onto the base plate 102a or onto protective
material covering the base plate 102a. The stitching or bonding
forms a flexible seam, which functions as a hinge device about
which the reflective leaves 102a may pivot between face-down and
upright positions.
[0069] In some embodiments, the reflective base 102a and leaves
102b are constructed of a flexible material, such as the membrane
material used for the sidewall 14, top panel 12, or bottom panel
13. A metallic foil can then be laminated or bonded onto the
membrane material of the leaves and base. Changes in the amount of
tension in the securement lines 51a, 51b causes all the flexible,
reflective base 102a and leaves 102b to bend or flex relative to
each other. When the inflatable structure 11 is fully inflated,
tension in the securement lines 51a, 51b is at a level that causes
all the flexible, reflective leaves 102b to unfurl and stretch out
so that they become substantially planar and form eight 3-surface
orthogonal reflectors such as shown for the reflector devices of
FIG. 5-9.
[0070] It is to be understood that radar reflector devices
described above are passive devices in the sense that they do not
generate and/or transmit an electromagnetic signal. The radar
reflector devices 50, 50', 100 require no power source, which
enables the buoyant target 10 to operate indefinitely. The radar
reflector devices 50, 50', 100 are configured to reflect
non-visible electromagnetic radiation, such as a radar signal. The
radar reflector devices 50, 50', 100 are configured to reflect
radar signals having frequencies, known in the art, used for
aircraft and maritime navigation and for gunnery exercises.
[0071] In FIG. 13, an electronic device 150 is attached to the
interior surface of the top panel 12 and is disposed within the
chamber 16 of the inflatable structure 11. The electronic device
150 is an active device that comprises a power source and
electronic circuitry. Instead of reflecting an electromagnetic
signal, the electronic device 150 is configured to transmit an
electromagnetic signal. The electronic device 150 can be remotely
controlled to selectively transmit the electromagnetic signal at a
desired time. The electromagnetic signal can be transmitted by the
electronic device 150 continuously and/or periodically. The
electronic device 150 can be configured to monitor and receive a
radar signal from an aircraft or a ship, and transmit an
electromagnetic signal in response to the received signal. The
transmitted electromagnetic signal can be at a frequency selected
based on the received signal.
[0072] In some embodiments, the buoyant target includes no drogue
chute and no tow line. No anchor device or a different type of
anchor device may be attached to the inflatable structure of the
buoyant target, as desired. Instead of a drogue chute, another
stabilizing device can be attached to the bottom end of the
inflatable structure to prevent the buoyant target from tipping
over of tilting excessively due to wave motion and wind.
[0073] According to another aspect the buoyant target 10 is a
floating ship decoy designed to confuse missile and gunfire laser
and radar targeting systems. For ship decoys, deployment speed is
critical, there is no time to rig a sea anchor or even manually
inflate 2 dozen decoys. There are minutes at best, seconds at the
worst. The criteria for a successful decoy is short deployment
reaction time and a very large laser image relative to the image of
the ship that is trying to evade incoming missiles armed with
multiple self-directed warheads.
[0074] It is desirable to have a rapid deployment for decoys. In
one embodiment a decoy taking the form of buoyant target 10
includes, in combination, an automatic self-inflation system such
as the system described in U.S. Pat. No. 4,280,239 when the decoy
is in a stowed configuration. For example, one or more of the
decoys 10, when in a stowed configuration, may be held within a
container having upper and lower halves 32 and 34, and wrapped
within straps 36. A canister or bottle of compressed fluid, e.g.,
carbon dioxide, having a valve coupled to the valve 15 of the decoy
10 (or several decoys each coupled to the compressed fluid) may be
opened by one or more lanyards 24 in a manner similar to the
lanyard 24 described in U.S. Pat. No. 4,280,239. Alternatively the
decoy may be deployed as the life raft is deployed using a lanyard
and pressurized fluid as described in U.S. Pat. No. 4,457,730. In
this manner several ship decoys may be deployed very rapidly when
needed. In another embodiment the automatic inflation and as set
forth in U.S. Pat. Nos. 4,280,239 and 4,457,730 may be used to
inflate several decoys simultaneously, or in succession. For
example, a tube may connect the valve of the compressed fluid to
each of the valves 15 of the decoys 10. In this manner, several
decoys 10 may be first positioned out in the water then a lanyard
used to remotely inflate the decoys. Alternatively, a remotely set
charge, e.g., explosive bolt or flange, may be used to open a valve
of the inflation source, thereby rapidly inflating one or more
decoys.
[0075] U.S. Pat. Nos. 4,280,239 and 4,457,730 are incorporated
herein by reference in their entirety. To the extent there are any
inconsistent usages of words and/or phrases between an incorporated
publication or patent and the present specification, these words
and/or phrases will have a meaning that is consistent with the
manner in which they are used in the present specification.
[0076] The laser-reflective surfaces discussed above can be
retroreflective surfaces. A retroreflective surface is capable of
reflecting light back to its source with minimal scattering of
light. A laser can be reflected back to its source even when the
laser beam is not perpendicular to the retroreflective surface. The
laser-reflective surface can be in the form of a laser-reflective
tape having retroreflective material, such as 3M (R) reflective
tape #3150A or similar reflective sheet material. A
laser-reflective tape can be flexible and have a front side that is
silver in color during daytime and configured to reflect a bright
white. Other colors can be implemented. Optionally, the
laser-reflective tape can have a pressure sensitive adhesive layer
on the back side. The laser-reflective tape can be used to cover
the reflector members, bodies, and prisms discussed above.
[0077] While several particular forms of the invention have been
illustrated and described, it will also be apparent that various
modifications can be made without departing from the scope of the
invention. It is also contemplated that various combinations or
subcombinations of the specific features and aspects of the
disclosed embodiments can be combined with or substituted for one
another in order to form varying modes of the invention.
Accordingly, it is not intended that the invention be limited,
except as by the appended claims.
* * * * *