U.S. patent application number 13/021761 was filed with the patent office on 2012-03-08 for deployable collapsible engineered material systems for runway safety.
Invention is credited to Jahangir S. Rastegar, Thomas Spinelli.
Application Number | 20120057930 13/021761 |
Document ID | / |
Family ID | 40583040 |
Filed Date | 2012-03-08 |
United States Patent
Application |
20120057930 |
Kind Code |
A1 |
Rastegar; Jahangir S. ; et
al. |
March 8, 2012 |
Deployable Collapsible Engineered Material Systems For Runway
Safety
Abstract
A collapsible material system for slowing a vehicle. The system
including: a predetermined thickness of collapsible material
disposed over a base; a covering disposed over a top surface of the
collapsible material over which the vehicle travels; and a
transition portion that further includes: a predetermined thickness
of collapsible transition material disposed over a base; and a
transition covering disposed over a top surface of the collapsible
material over which the vehicle travels. Where one of the
collapsible transition material and the transition covering have a
different characteristic from the collapsible material and the
covering, respectively.
Inventors: |
Rastegar; Jahangir S.;
(Stony Brook, NY) ; Spinelli; Thomas; (East
Northport, NY) |
Family ID: |
40583040 |
Appl. No.: |
13/021761 |
Filed: |
February 6, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11980285 |
Oct 30, 2007 |
7905678 |
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13021761 |
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Current U.S.
Class: |
404/6 |
Current CPC
Class: |
E01F 13/123 20130101;
B64F 1/025 20130101 |
Class at
Publication: |
404/6 |
International
Class: |
E01F 15/00 20060101
E01F015/00; E01F 13/00 20060101 E01F013/00 |
Claims
1. A collapsible material system for slowing a vehicle, the system
comprising: a predetermined thickness of collapsible material
disposed over a base; a covering disposed over a top surface of the
collapsible material over which the vehicle travels; and a
transition portion comprising: a predetermined thickness of
collapsible transition material disposed over a base; and a
transition covering disposed over a top surface of the collapsible
material over which the vehicle travels; and wherein one of the
collapsible transition material and the transition covering have a
different characteristic from the collapsible material and the
covering, respectively.
2. The collapsible material system of claim 1, wherein the
different characteristic is a different orientation of the
transition covering.
3. The collapsible material system of claim 1, wherein the
different characteristic is a different resistance to compression
of the transition material.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Divisional Application of U.S.
application Ser. No. 11/980,285, filed on Oct. 30, 2007, the entire
contents of which is incorporated herein by its reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates generally to emergency
apparatus for use with aircraft runways, and more particularly, to
collapsible concrete systems for runways.
[0004] 2. Prior Art
[0005] Runway segments are sometimes added to the end of runways
that are constructed with a special type of "concrete" that
collapses in a more or less controlled manner under the load of an
airplane tire, generally referred to as Engineered Material
Arresting System (EMAS). Such runway segments have the problem of
lack of control because the collapsed EMAS tends to constrain the
tire to travel, more or less, in the generated "groove", making it
difficult for the plane to maneuver (turn) sideways due to the
resistance that the uncrushed "EMAS wall" provides against the tire
as it attempts to turn sideways.
[0006] In addition, the EMAS material cannot be formed such that it
is sufficiently homogeneous to prevent bumpy rides.
[0007] In addition, the collapsible EMAS runway breaks up into
smaller pieces that can be projected out towards the aircraft, thus
creating a safety hazard.
[0008] In addition, the collapsible EMAS runway cannot support the
weight of the vehicle that is intended to use it in emergency
situation. As a result, the collapsible EMAS runway sections cannot
be used for regular landing and take-off of aircraft.
[0009] In addition, once used by an aircraft to slow its speed and
bring it to a stop, the collapsible EMAS runway section becomes
essentially unusable. As a result, the related runway may have to
be closed for a relatively long periods to allow the repair crew to
repair the damaged section of the collapsible EMAS runway
section.
SUMMARY
[0010] Therefore, there exists a need in the art to overcome the
deficiencies of the collapsible EMAS systems of the prior art.
[0011] Accordingly, a collapsible material system for slowing a
vehicle is provided. The system comprising: a predetermined
thickness of collapsible material disposed over a base; a plurality
of panels disposed over a top surface of the collapsible material
over which the vehicle travels; and a support structure for
supporting one or more of the plurality of panels in a first
position and for allowing the collapsible material to be compressed
under the weight of the vehicle in a second position.
[0012] The collapsible material system can further comprise a hinge
disposed between adjacent panels of the plurality of panels. The
hinge can be disposed to pivot about an axis parallel to a
direction of travel of the vehicle. The hinge can be disposed to
pivot about an axis perpendicular to a direction of travel of the
vehicle. The hinge can further comprises a seal.
[0013] The collapsible material system can further comprise a seal
disposed between adjacent panels of the plurality of panels.
[0014] The collapsible material system can further comprise a
transition portion comprising: a predetermined thickness of
collapsible transition material disposed over a base; one or more
transition panels disposed over a top surface of the collapsible
material over which the vehicle travels; and a transition support
structure for supporting the one or more panels in a first position
and for allowing the collapsible material to be compressed under
the weight of the vehicle in a second position; wherein one of the
collapsible transition material and the one or more transition
panels have a different characteristic from the collapsible
material and the plurality of panels, respectively. The different
characteristic can be a different orientation of the one or more
transition panels. The different characteristic can be a different
resistance to compression of the transition material.
[0015] The support structure can comprise: a linkage having two or
more links, one of the two or more links being connected to the
base and the other of the two or more links being connected one or
more of the plurality of panels; and one or more locking elements
for selectively locking and unlocking the linkage between a locked
state corresponding to the first position and an unlocked state
corresponding to the second position.
[0016] The support structure can comprise: a tubular member
connected to one of the base and one or more of the plurality of
panels; and one or more members slidingly disposed with the tubular
member connected to the other of the base and one or more of the
plurality of panels; wherein the one or more member are actuatable
between a locked state corresponding to the first position and an
unlocked state corresponding to the second position.
[0017] Also provided is a collapsible material system for slowing a
vehicle. The system comprising: a predetermined thickness of
collapsible material disposed over a base; a covering disposed over
a top surface of the collapsible material over which the vehicle
travels; and a transition portion comprising: a predetermined
thickness of collapsible transition material disposed over a base;
and a transition covering disposed over a top surface of the
collapsible material over which the vehicle travels; and wherein
one of the collapsible transition material and the transition
covering have a different characteristic from the collapsible
material and the covering, respectively.
[0018] The different characteristic can be a different orientation
of the transition covering. The different characteristic can be a
different resistance to compression of the transition material.
[0019] Still further provided is a method for slowing a vehicle.
The method comprising: disposing a predetermined thickness of
collapsible material over a base; disposing a plurality of panels
over a top surface of the collapsible material over which the
vehicle travels; and selectively either supporting one or more of
the plurality of panels or allowing the collapsible material to be
compressed under the weight of the vehicle.
[0020] The method can further comprise pivoting adjacent panels of
the plurality of panels with respect to each other.
[0021] The method can further comprise sealing between adjacent
panels of the plurality of panels.
[0022] The method can further comprise: providing a transition
portion comprising: a predetermined thickness of collapsible
transition material disposed over a base; one or more transition
panels disposed over a top surface of the collapsible material over
which the vehicle travels; and a transition support structure for
supporting the one or more panels in a first position and for
allowing the collapsible material to be compressed under the weight
of the vehicle in a second position; and providing one of the
collapsible transition material and the one or more transition
panels have a different characteristic from the collapsible
material and the plurality of panels, respectively.
[0023] The providing of the one of the collapsible transition
material and the one or more transition panels to have a different
characteristic from the collapsible material and the plurality of
panels can comprises differing an orientation of the one or more
transition panels.
[0024] The providing of the one of the collapsible transition
material and the one or more transition panels to have a different
characteristic from the collapsible material and the plurality of
panels can comprises differing a resistance to compression of the
transition material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] These and other features, aspects, and advantages of the
apparatus and methods of the present invention will become better
understood with regard to the following description, appended
claims, and accompanying drawings where:
[0026] FIG. 1 illustrates an embodiment of a deployable collapsible
EMAS materials based system having substantially rigid structures
deployed.
[0027] FIG. 2 illustrates the deployable collapsible EMAS materials
based system of FIG. 1 in which a wheeled vehicle travels over the
same.
[0028] FIG. 3 illustrates the deployable collapsible EMAS materials
based system of FIG. 1 with the substantially rigid structures in a
retracted (un-deployed state).
[0029] FIG. 4 illustrates the deployable collapsible EMAS materials
based system of FIG. 3 where a wheeled vehicle has collapsed a
portion thereof.
[0030] FIG. 5 illustrates a variation of the deployable collapsible
EMAS materials based system of FIG. 4 having a transition
region.
[0031] FIG. 6 illustrates another embodiment of a deployable
collapsible EMAS materials based system with the substantially
rigid structures in a retracted (un-deployed state).
[0032] FIG. 7 illustrates the deployable collapsible EMAS materials
based system of FIG. 7 having a transition region.
[0033] FIG. 8 illustrates an embodiment of a substantially rigid
structure.
[0034] FIG. 9 illustrates another embodiment of a substantially
rigid structure.
[0035] FIG. 10 illustrates yet another embodiment of a
substantially rigid structure.
[0036] FIG. 11 illustrates a top view of another embodiment of a
deployable collapsible EMAS materials based system.
DETAILED DESCRIPTION
[0037] Although this invention is applicable to numerous and
various types of roadways and surfaces, it has been found
particularly useful in the environment of runways for aircraft.
Therefore, without limiting the applicability of the invention to
runways for aircraft, the invention will be described in such
environment. Those skilled in the art will appreciate that the
collapsible EMAS materials based systems of the present invention
can be used on roadways for automobiles and trucks and for other
wheeled vehicles.
[0038] Referring now to FIG. 1, there is shown a first embodiment
of a deployable collapsible EMAS materials based (hereinafter
referred to as collapsible material based) system, generally
referred to by reference numeral 100. The collapsible material
based system 100 has a predetermined thickness t of collapsible
material 102 over a base 104. The fabrication of collapsible
material and the proper thickness for the same for different
applications is well known in the art. Generally, the collapsible
material can be provided in blocks and stacked along the base 104
to cover an appropriate portion of the base. The collapsible
material system 102 further has relatively rigid panels 105, which
can be separate from each other or preferably interconnected, such
as by a hinge 106 to allow relative rotation about axes lateral to
the direction of travel 107.
[0039] The hinges 106 that connect the panels 105 may be
constructed as a narrow "strip" of relatively flexible material
(not shown) to join the panels as well as seal the collapsible
material 102 and protect it from elements such as rain, snow, etc.,
and essentially act as living joints. Alternatively, even when
mechanical hinges 106 are used, the panels may still be joined
together on the top surface with similar narrow strip of relatively
flexible material to protect the underlying collapsible material
102. The provision of such narrow strip of relatively flexible
material would have the added advantage of providing the
collapsible materials based system 100 with a smooth surface.
[0040] The panels 105 are supported by substantially rigid
structures 108, such that under the load transmitted by the wheel
110 of a typical vehicle 111 that will use the system 100, as shown
in FIG. 2, it would not cause the collapsible material system 102
to be crushed.
[0041] The support structures 108 are, however, deployable, i.e.,
in its deployed state they are substantially rigid structures and
would support the load exerted by the wheel 110 of the passing
vehicle 111 over the supported panels 105. In their un-deployed
(retracted) state 113, the supports provide minimal to no
resistance to the load exerted by the wheel 110 of the passing
vehicle 111 over the "un-supported" panels 105, thereby allowing
the said load to press the panels 105 against the collapsible
material system 102, FIG. 3. This would then cause the collapsible
materials 102 to be crushed as shown in FIG. 4 to certain depth 115
(the fully crushed region is indicated as 114) depending on the
load exerted by the wheel 110 of the passing vehicle 111, thereby
absorbing the kinetic energy of the passing vehicle and eventually
bringing it to a stop or slowing it down as intended by the system
user and/or designer. Hereinafter, the aforementioned support
structures 108 are referred to as "deployable support
structures".
[0042] The different methods of providing the aforementioned
deployable support structures and their various embodiments are
described below.
[0043] The length (L), FIG. 1, of the panels 105 is chosen
depending on the size of the typical wheel that will use the system
(or a range of wheel sizes). The width of the panels 105
(perpendicular to the direction of travel 107) can vary from the
width of the typical wheel that will use the system (and perhaps
even smaller) to the width of the runway, however, in general, the
larger the surface area of the panel 105, the less crushing force
is exerted on the collapsible material covered by the panel
105.
[0044] The hinges 106 may be provided with certain amount of
flexibility and/or play to allow certain amount of relative
displacement between the panels 105 in the vertical plane of the
schematic cross-sections of FIGS. 1-2. Such relative displacements
would accommodate certain amount of rotation and downward motion of
one panel 105 relative to the next panel as a typical wheel 110
rolls over panels 105 as shown in FIG. 3. Thus, the hinges 106
would allow the panels 105 to assume a sloped configuration as the
vehicle 111 wheel 110 rolls over a panel and to push the leading
edge 112 down as shown in FIG. 3.
[0045] In general, the side by side panels 105, i.e., the panels
positioned side by side in the direction perpendicular to the
direction of the travel 107 of the vehicle 111 are preferably
connected by flexible elements (not shown) so that the depression
of one panel 105 under the weight of the vehicle 111 transmitted by
the wheel 110 to the said panel would also exert a force on the
sides of the adjacent panels to avoid the creation of abrupt
discontinuities.
[0046] In the FIGS. 1-4, all the like features are denoted by
identical reference numerals.
[0047] To make the transition from the regular section of a runway
119 commonly constructed with concrete 117, FIG. 5, to the
deployable collapsible materials based system section 100, a
slightly sloped transition section 118 is constructed with similar
panels 105 that are hinged together with similar hinges 106, and
supported by appropriately sized support structures 108. Similar
collapsible material 102 that are appropriately sized 116 are
similarly used to fill the space between the panels 105 of the
transition section 118 and the base 104 as shown in FIG. 5. The
transition section 118 would allow the vehicle 111 to begin to
decelerate slowly and smoothly to its final deceleration rate as
the wheel 110 of the vehicle 111 travels from the regular section
of the runway 119 over to the transition section 118 and from there
to the deployable collapsible materials based system section
100.
[0048] The resulting runway section having the collapsible concrete
system 100 will then act very similar to the runway system
described in U.S. Pat. No. 6,969,213 entitled "Roadway for
Decelerating a vehicle Including an Aircraft," the entire contents
of which is incorporated herein by reference. In the present
collapsible concrete system, 100, the collapsible concrete 102 and
116 (FIGS. 1-5) is used in place of the support and control
elements disclosed in U.S. Pat. No. 6,969,213. The difference is
that when substantially rigid support structures 108 (FIGS. 1, 2
and 5) are in their retracted state 113 (FIGS. 3-4), the kinetic
energy of the vehicle is used to crush the collapsible concrete
(collapsible EMAS materials) rather than being stored in springs or
absorbed by dampers or brake elements. Thus, as shown in FIG. 5, as
a wheel 110 of the vehicle 111 enters the collapsible EMAS
materials system 100, the wheel 110 first enters the transition
section 118 from the regular runway section 119 as shown in FIG. 5.
The load transmitted by the wheel 110 will then begin to press the
panels 105 of the transition section 118, forcing the panels to
crush the collapsible materials 116 under the transition section
118. The wheel will then reach the level section of the collapsible
EMAS materials system 100, and keep on depressing the panels 105
down and crush the collapsible materials 102 to certain height 115,
FIG. 4, which is dependent on the level of load transmitted by the
wheel 110 of the vehicle 111.
[0049] In addition to the panels 105 preventing debris from being
thrown, another advantage of using such panels 105 over collapsible
EMAS materials 102 (116) is that the vehicle travels much smoother
since it would average out the strength of the collapsible EMAS
materials system 102 (116), the homogeneity of which is hard to
control.
[0050] Still another advantage of the collapsible EMAS materials
system 100 is that there is no resulting loss of control of the
vehicle 111 as it travels over the panels 105 rather than in
grooves generated by the sinking wheel 110 in the collapsible EMAS
materials 102 (116) in the absence of the panels 105.
[0051] Still another advantage of the collapsible materials system
100 is that with the substantially rigid support structures 108
deployed (FIGS. 1, 2 and 5), the system 100 is substantially rigid
and the load transmitted by the wheel 110 of the vehicle 111 will
be carried substantially by the substantially rigid support
structure 108. The section 100 would therefore function as a
regular section of a runway and add to the total length of the
regular runway, a feature which is highly desirable for all
runways. However, when an emergency situation is encountered, the
substantially rigid support structures 108 are retracted to their
un-deployed (retracted) state, FIGS. 2-3, and the vehicle 110
traveling in the direction 107 is decelerated safely to a stop.
[0052] Still another advantage of the collapsible EMAS materials
system 100 is that following an emergency use of the section of the
runway to decelerate a vehicle, for example a runaway aircraft, the
substantially rigid support structures 108 may again be deployed
and the section of the runway used for ordinary landing while the
damaged collapsible EMAS materials (102 and 116, FIG. 5) sections
are ready to be replaced. As a result, the runway does not have to
be closed while the collapsible EMAS materials (102 and 116, FIG.
5) sections are being made. In addition, the collapsible EMAS
materials system 100 is still mostly effective since the chances of
a second runaway vehicle to follow exactly the path of a previous
runaway vehicle is very small.
[0053] In another embodiment, the schematics of which is shown in
FIG. 6, a collapsible materials based system 120 is constructed
such that the panels 121 connected together with hinges 132 are
flush with the regular runway section 122, both for the transition
section 123 panels and the main section 124 panels. In their
deployed state, the aforementioned substantially rigid support
structures 133 support the panels 121, such that under the load
transmitted by the wheel 125 of a typical vehicle 126 that will use
the system 120, as shown in FIG. 6, it would not cause the
collapsible materials 128 and 130 to be crushed. The collapsible
EMAS materials 128 and 130 of both sections 123 and 123 and the
substantially rigid support structures 133 are supported by a
similar base (foundation) structure 134.
[0054] However, the transition from the regular runway section 122
to the collapsible materials based system 120 is highly desirable
to be smooth for the wheel 125 of the vehicle 126, i.e., the wheel
125 of the vehicle 126 is desired to slowly increase its vertical
(downward) travel (i.e., crushing depth of 127 of the collapsible
EMAS materials 128) as it moves from the regular runway section 122
to over the panels 121 to its nominal depth 129, FIG. 7. To this
end, the collapsible EMAS materials 128 following the regular
runway section 122 in the transition section 123 is made out of
stronger collapsible EMAS materials, i.e., collapsible EMAS
materials that crush less under the same load, and then become
progressively weaker to the nominal strength of the collapsible
EMAS materials 130 of the remaining section 124 of the collapsible
EMAS materials system 120. As a result, as the wheel 125 of the
vehicle 126 traveling in the direction 131 enters the section of
the runway constructed with the collapsible materials based system
120, the first few panels 121 positioned along the aforementioned
transition section 123 are depressed due to the crushing of the
stronger collapsible EMAS materials 128 continuously more to bring
the wheel 125 smoothly to its nominal depth 129 over the remaining
section 124 of the collapsible materials system 120 as shown in
FIG. 7.
[0055] The support structures (108 in FIGS. 1-2 and 5 and 133 in
FIGS. 6-7), while supporting the vehicle load over the
substantially rigid panels (105 in FIGS. 1-5 and 121 in FIGS. 6 and
7), are constructed to prevent the collapsible materials (102 in
FIGS. 1-5 and 128 and 130 in FIGS. 6 and 7) from being crushed
under the weight of the vehicle (111 in FIGS. 2-5 and 126 in FIGS.
6 and 7) as transmitted by the vehicle tires (110 in FIGS. 2-5 and
125 in FIGS. 6 and 7). The support structures 108 and 133, however,
are capable of being released, i.e., being made incapable of
supporting the aforementioned vehicle load, thereby allowing
crushing of the collapsible materials (102, 128 and 130) under the
vehicle load.
[0056] The support structure releasing action may be initiated
manually, for example by the flight control personnel or by the
aircraft crew, or may be initiated automatically when sensors
measuring the speed of the landing aircraft determine that the
aircraft is moving too fast and may run past the runway. The
automatic means of release mechanism initiation may also be onboard
the aircraft and initiate the release directly or by communicating
with a runway station. The support structures 108 and 133 and their
release mechanisms may be constructed in a varieties of ways, some
of which are described in the following embodiments.
[0057] In general, the mechanisms for the support structures 108
and 133 can be configured to either retract out of the direction of
collapsible material (102, 128 and 130) crushing, or can be
configured to move with the panels (105 and 121) with minimal
resistance. Alternatively, while moving with the panels 105 and
121, the support structures may also provide certain amount of
(braking-like) resistance, thereby absorbing a portion of the
kinetic energy of the vehicle.
[0058] In one embodiment, the support structures 108 and 133 are
designed as linkage mechanisms with a releasable locking element,
which when locked, would transform the mechanism to a
(substantially rigid) structure (no degree-of-freedom for motion),
supporting the vehicle load on the panels 105 and 121 as previously
described. However, once the locking mechanism is released, the
linkage mechanism is essentially free to "collapse", thereby
allowing the panels 105 and 121 to crush the underlying collapsible
materials (102, 128 and 130).
[0059] In one embodiment, the linkage mechanism types used for the
construction of the present support structures 108 and/or 133 have
at least two degrees-of-freedom in motion to allow arbitrary motion
of the panels 105 and 121 relative to the base foundation (104 in
FIGS. 1-5 and 134 in FIGS. 6-7). In general, fewer
degrees-of-freedom in motion is preferable since it would require
fewer locking elements to transform the mechanism into a
substantially rigid structure (in general, one such locking
mechanism is required for each degree-of-freedom of the linkage
mechanism to transform the mechanism into a substantially rigid
structure).
[0060] One such degree-of-freedom linkage mechanism embodiment for
the construction of the present support structures 108 and/or 133
is shown in the schematic drawing of FIG. 8. This mechanism is
constructed with two links 142 and 143, which are connected
together with a hinge 146. The link 142 is hinged to the panel 141
through the attachment support 144. The link 143 is in turn
attached to the runway foundation 151 through the support 145. The
panels 141 are shown to be attached to each other by hinges 140.
The locking elements 147 and 149 are provided to prevent rotary
motion of the links 143 and 142, respectively, relative to the
runway foundation, portions of which are shown as 148. It is noted
that in the schematic of FIG. 8 and for the sake of simplicity the
locking elements 147 and 149 are shown only on one side the links
143 and 142, but in an actual device the locking elements are
intended to provide locking elements positioned on both sides of
the links (e.g., by providing U shaped elements instead of blocks
147 and 149 as shown in FIG. 8) to restrict the links 143 and 142
from undergoing any rotational motions. When the locking elements
147 and 149 are preventing the links 143 and 142 from rotating, the
two links function as a structure, i.e., function as substantially
rigid support structures 108 and 133, thereby supporting the load
150 exerted by the vehicle wheel (110 and 125 in FIGS. 1-7) on the
panels 141, thereby preventing the panel to be pushed down and
crush the collapsible materials 102 or 128 and/or 130 (not shown in
FIG. 8). When a vehicle traveling over the runway section needs to
be slowed down, the locking elements 147 and 149 are withdrawn,
thereby preventing the links 143 and 142 (the linkage mechanism) to
provide a substantial resistance to the applied load 150, thereby
allowing the panels 141 to crush the collapsible materials 102 or
128 and/or 130, absorbing part of the kinetic energy of the vehicle
and therefore slowing the vehicle down.
[0061] The links 149 and 147 (linkage mechanism) may be provided
with spring elements (not shown) to bias them into their collapsed
position. The linkage mechanism may also be provided with braking
elements (frictional or viscous damping type) to absorb parts of
the kinetic energy of the passing vehicle as the weight of vehicle
pushes the panels 141 down to crush the collapsible materials 102
or 128 and/or 130.
[0062] In another embodiment of the present invention, the linkage
mechanism type used for the construction of the present support
structures 108 and/or 133 has only one degrees-of-freedom in
motion; thereby would only allow the panels 105 and 121 to undergo
a prescribed motion relative to the runway foundation (104 and
134). The prescribed motion is preferably the actual motion pattern
of the panels 105 and 121 as the vehicle load is applied to the
surface of the panels and travel along its length, causing the
collapsible materials 102 or 128 and/or 130 to crush. However,
since this pattern of motion for the panels 105 and 121 is
different for different vehicles and their speed, one compromise
would be to provide linkage mechanisms that allow only vertical
motion, and attach them to the panels by a, preferably, spherical
joint that would allow for rotational motion of the panels 105 and
121 about axes parallel to the plane of the foundation, i.e.,
usually the horizontal plane. The rotation of the panels 105 and
121 about the vertical axis is prevented since more than one
support structure 108 and/or 133 is used for each said panels.
[0063] One such an embodiment is designed as a "scissor" type of
linkage mechanism 160 shown in the schematic drawing of FIG. 9. The
scissor mechanism is constructed with a series of pairs of links
171 that are joined together as shown in FIG. 9 with hinges 172. On
the foundation 170 side, one of the links 171 is hinged to the
support 165, which is in turn fixed to the foundation 170. The
other link 171 of the scissor mechanism 160 is hinged to the
support 166. The support 166 rests over the surface of the
foundation 170 and is free to translate along the line connecting
the supports 165 and 166. Similarly on the panel 161 side, one of
the links 171 is hinged to the support 164, which is fixed to the
plate 173. The other link 171 is then hinged to the support 175,
which is free to translate along the line connecting the supports
164 and 175. The panel 161 is then supported by the scissor type
mechanism via the ball joint 174. The panels 161 are attached
together as previously described by the hinge joints 162. The ball
joint 174 may be a living joint.
[0064] In the schematic drawing of FIG. 9, the translation of the
support 166 over the surface of the foundation 170 away from the
fixed support 165 is prevented by the locking element 168 which is
positioned between the support 166 and the stop 167, which is fixed
to the foundation 170. When the locking element 168 is positioned
as shown in FIG. 9 between the support 166 and the stop 167, then
the scissor mechanism 160 is substantially rigid and the top plate
173 can support the vehicle load 169 that is applied to the panel
161 as the vehicle travels over the said panel. However, when the
locking element 168 is pulled away from its aforementioned locking
position shown in FIG. 1, then the support 166 is free to translate
away from the fixed support 165, thereby allowing the scissor
mechanism to collapse, thereby allowing the panel 161 to crush the
collapsible materials 102 or 128 and/or 130 as the vehicle travels
over the panel 161 and applies the load 169 to the said panel.
[0065] As described for the mechanism of FIG. 8, the links 171
(linkage mechanism) may be provided with spring elements (not
shown) to bias them into their collapsed position. The linkage
mechanism may also be provided with braking elements (frictional or
viscous damping type) to absorb a portion of the kinetic energy of
the passing vehicle as the weight of the vehicle pushes the panels
161 down to crush the collapsible materials 102 or 128 and/or 130
(not shown).
[0066] In yet another embodiment, the support structures 108 and/or
133 is constructed as a one degree-of-freedom telescopic column
type of mechanism 180 shown in the schematic drawing of FIG. 10.
Here, the mechanism 180 is shown to consist of a moving section 185
(can be cylindrical or other shapes), which could travel down
inside the second tubular section 186. The section 186 is fixed to
the foundation 183, and is preferably buried substantially inside
the foundation for increased support and to allow the section 185
to move down a sufficient amount for the proper operation of the
present system. The locking element 188 provides the means to lock
the section 185 of the telescopic mechanism 180 up in the position
shown in FIG. 10. In this position, the telescopic mechanism
functions as a support structure support structures 108 and/or 133,
and support the load 184 applied by the tire of the vehicle passing
over the panel 181 via the ball joint 187. The panels 181 are
attached together as previously described by the hinge joints 182.
The ball joint 187 may be a living joint.
[0067] When the locking element 187 is pulled out of the telescopic
(column) mechanism 180, the section 185 is free to retract into the
section 186, thereby allowing the panel 181 to crush the
collapsible materials 102 or 128 and/or 130 (not shown) as the
vehicle travels over the panel 181 and applies the load 184 to the
said panel.
[0068] As described for the mechanisms of FIGS. 8 and 9, spring
elements (not shown) may be used to bias the translation of the
section 185 inside the section 186 of the telescopic mechanism 180
to bias the mechanism into its collapsed position. The telescopic
mechanism may also be provided with braking elements (frictional or
viscous damping type) to absorb parts of the kinetic energy of the
passing vehicle as the weight of vehicle pushes the panels 181 down
to crush the collapsible materials 102 or 128 and/or 130 (not
shown).
[0069] Such telescopic column type mechanisms may also be
constructed with more than one telescopic section to minimize the
length of the buried section 186. However, since each section has
to be provided with a separate locking element 188, the resulting
support structure will have more components and more locking
elements to be removed when the runway section is intended to be
used to slow the passing vehicle.
[0070] Referring now to FIG. 1, there is shown a top view of
another embodiment of a collapsible material based system 200. In
the embodiment of FIG. 11, in addition to the panels 105 being
pivotal about hinges (or flexures) 106 which pivot about an axis
perpendicular to the direction of travel 107, the panels 105 can
also be pivotal about hinges (or flexures 202) which pivot about an
axis parallel to the direction of travel so as to arrest any
component of motion of the aircraft in the sideways direction which
would otherwise cause the aircraft to leave the side of the runway.
In such an embodiment, an appropriate number of support structures
108 are needed to support each panel 105, such as three or more of
such support structures 108 per panel 105. The side-to-side
(perpendicular to the direction of travel 107) spacing of the
hinges 202 can be more, less or the same as the lengthwise spacing
between hinges 106. However, it is preferred that the side-to-side
spacing between hinges 202 is greater than the lengthwise spacing
between hinges 106 such that the panels are wider in the
side-to-side direction than they are in the lengthwise (direction
of travel 107) direction.
[0071] While there has been shown and described what is considered
to be preferred embodiments of the invention, it will, of course,
be understood that various modifications and changes in form or
detail could readily be made without departing from the spirit of
the invention. It is therefore intended that the invention be not
limited to the exact forms described and illustrated, but should be
constructed to cover all modifications that may fall within the
scope of the appended claims.
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