BACKGROUND OF THE INVENTION
[0001] This invention relates in general to impact absorbing underlayment panels. In particular,
this invention relates to underlayment panels having deformable elements that compress
in a plurality of stages such that a load absorbing gradient is provided in response
to an applied force.
[0002] Surfaces such as playground and athletic mats, for example, are scrutinized for their
effect on impact forces that cause related injuries to users. Attempts have been made
to minimize the force or energy transferred to a user's body in the event of a fall.
Various surface designs that rely on ground materials or layered fabric materials
may help reduce the transfer of impact forces. These surface designs, however, are
limited by the ability of the materials to spread the impact load over a large area.
Thus, it would be desirable to provide a surface having improved impact force absorption
and dissipation characteristics.
SUMMARY OF THE INVENTION
[0003] This invention relates to an impact absorption panel having a top side and a bottom
side. The top side includes a plurality of drainage channels that are in fluid communication
with a plurality of drain holes. The plurality of drain holes connect the top side
drainage channels with a plurality of bottom side channels. The bottom side channels
are defined by sides of adjacent projections that are disposed across the bottom side.
[0004] This invention also relates to an impact absorption panel having a top side and a
bottom side where the bottom side has a plurality of projections disposed across at
least a portion of the bottom surface. The projections have a first spring rate characteristic
and a second spring rate characteristic. The first spring rate characteristic provides
for more deflection under load than the second spring rate characteristic.
[0005] In one embodiment, an impact absorption panel comprises a top surface and a bottom
surface. The top surface has a three dimensional textured surface and a plurality
of intersecting drainage channels. The bottom surface is spaced apart from the top
surface and defines a panel section therebetween. A plurality of projections is disposed
across at least a portion of the bottom surface. The projections have a first stage
that defines a first spring rate characteristic and a second stage defining a second
spring rate characteristic. The first spring rate characteristic provides for more
deflection under load than the second spring rate characteristic. The plurality of
projections also cooperate during deflection under load such that the adjacent projections
provide a load absorption gradient over a larger area than the area directly loaded.
In another embodiment, the first stage has a smaller volume of material than the second
stage. Additionally, the adjacent projections define a bottom surface channel to form
a plurality of intersecting bottom surface channels and a plurality of drain holes
connect the top surface drainage channels with the plurality of bottom surface channels
at the drainage channel intersections.
[0006] In another embodiment, an impact absorption panel includes a top surface and a bottom
surface that define a panel section. A plurality of projections are supported from
the bottom surface, where the projections include a first stage having a first spring
rate and a second stage having a second spring rate. The first stage is configured
to collapse initially when subjected to an impact load, the second stage is configured
to provide greater resistance to the impact load than the first stage, and the panel
section is configured to provide greater resistance to the impact load than the first
and second stages. The first stage is also configured to compress and telescopically
deflect, at least partially, into the second stage. A portion of the bottom surface
is generally coplanar with the truncated ends of adjacent projections such that the
coplanar bottom surface portion is configured to provide a substantial resistance
to deflection under load compared with the first and second stages. This coplanar
configuration of the bottom surface provides a structural panel section having a thickness
that is generally equal to the thickness of the panel section plus the length of the
projections.
[0007] In yet another embodiment, an impact absorption panel system comprises a first panel
and at least a second panel. The first panel has a top surface, a bottom surface,
a first edge having a flange that is offset from the top surface and a second edge
having a flange that is offset from the bottom surface, A plurality of projections
are disposed across the bottom surface. The projections have a first spring rate characteristic
and a second spring rate characteristic. The second panel has a top surface, a bottom
surface, a first edge having a flange that is offset from the top surface and a second
edge having a flange that is offset from the bottom surface. A plurality of projections
are disposed across the bottom surface of the second panel and have a first spring
rate characteristic and a second spring rate characteristic. One of the second panel
first edge flange and the second edge flange engages one of first panel second edge
flange and the first panel first edge flange to form a generally continuously flat
top surface across both panels.
[0008] In one embodiment, the impact absorption panel is a playground base layer panel.
[0009] Various aspects of this invention will become apparent to those skilled in the art
from the following detailed description of the preferred embodiment, when read in
light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010]
Fig. 1A is an elevational view of a top side of an embodiment of an impact absorption
panel suitable as a playground base;
Fig. 1B is an enlarged elevational top view of an edge of the impact absorption panel
of Fig. 1A;
Fig. 1C is an enlarged elevational top view of a corner of the impact absorption panel
of Fig. 1A;
Fig. 2A is an elevational view of a bottom side of an embodiment of an impact absorption
panel;
Fig. 2B is an enlarged elevational bottom view of a corner of the impact absorption
panel of Fig. 2A;
Fig. 3 is a perspective view of an embodiment of a panel interlocking feature of an
impact absorption panel;
Fig. 4 is a perspective view of a panel interlocking feature configured to mate with
the panel locking feature of Fig. 3;
Fig. 5 is an elevational view, in cross section, of the assembled panel interlocking
features of Figs. 3 and 4.
Fig. 6 is an enlarged elevational view of an embodiment of a shock absorbing projection
of an impact absorption panel;
Fig. 7 is a perspective view of the bottom side of the impact absorption panel of
Fig. 6;
Fig. 8A is an enlarged elevational view of an embodiment of a deformed projection
reacting to an impact load; and
Fig. 8B is an enlarged elevational view of another embodiment of a deformed projection
reacting to an impact load.
Fig. 9 is an enlarged elevational view of another embodiment of a deformed projection
reacting to an impact load.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] Referring now to the drawings, there is illustrated in Figs. 1A, 1B, and 1C a load
supporting panel having an impact absorbing structure configured to underlie a playground
area. The various embodiments of the impact absorbing panel described herein may also
be used in indoor and outdoor impact environments other than playgrounds and with
other types of equipment such as, for example, wrestling mats, gymnastic floor pads,
carpeting, paving elements, loose infill material, and other covering materials. In
certain embodiments, the panel is described as a single panel and is also configured
to cooperate with other similar panels to form a base or impact absorbing panel system
that is structured as an assemblage of panels. The panel, shown generally at 10, has
a top surface 12 that is illustrated having a grid of drainage channels 14. Though
shown as a grid of intersecting drainage channels 14, the drainage channels may be
provided in a non-intersecting orientation, such as generally parallel drainage channels.
In the illustrated embodiment, a drain hole 16 is formed through the panel 10 at the
intersection points of the drainage channels 14. However, not every intersection point
is required to include a drain hole 16. The drain holes 16 may extend through all
or only a portion of the intersecting drainage channels 14 as may be needed to provide
for adequate water dispersion. Though illustrated as a square grid pattern, the grid
of drainage channels 14 may be any shape, such as, for example, rectangular, triangular,
and hexagon.
[0012] A first edge flange 18 extends along one side of the panel 10 and is offset from
the top surface 12 of the panel 10. A second edge flange 20 extends along an adjacent
side of the panel 10 and is also offset from the top surface 12. A third edge flange
22 and a fourth edge flange 24 are illustrated as being oriented across from the flanges
18 and 20, respectively. The third and fourth flanges 22 and 24 extend from the top
surface 12 and are offset from a bottom surface 26 of the base 12, as shown in Fig.
2A. The first and second flanges 18 and 20 are configured to mate with corresponding
flanges, similar to third and fourth flanges 22 and 24 that are part of another cooperating
panel. Thus, the third and fourth flanges 22 and 24 are configured to overlap flanges
similar to first and second flanges 18 and 20 to produce a generally continuous surface
of top surfaces 12 of adjoining panels 10. A panel section 27, as shown in Fig. 5,
is defined by the thickness of the panel between the top surface 12 and the bottom
surface 26.
[0013] In an alternative embodiment, the panel 10 may be configured without the first through
fourth flanges 18, 20, 22, and 24. In such a configuration, the resulting edges of
the panel 10 may be generally flat and straight edges. In another embodiment, the
generally straight edge may include projections (not shown) to create a gap between
adjoining panels, as will be explained below. In yet another embodiment, the edges
may be formed with an interlocking geometric shape similar to a jigsaw puzzle. Referring
now to Figs. 2A and 2B, there is illustrated the bottom surface 26 of the panel 10.
The illustrated bottom surface 26 includes a plurality of projecting shock absorbing
structures 28 disposed across the bottom surface 26. Only some of the projections
28 are shown on the bottom surface 26 so that the drain holes 16 may be clearly visible.
Thus, in one embodiment, the projections 28 extend across the entire bottom surface
26. In another embodiment, the projections 28 may be arranged in a pattern where portions
of the bottom surface have no projections 28. The portion having no projections 28
may have the same overall dimension as the thickness of the panel 10 including the
projections 28. Such a section may be configured to support a structure, such as a
table and chairs. This portion of the bottom surface 26 is configured to provide a
structural support surface having a substantial resistance to deflection under load
compared with the first and second stages 40 and 42.
[0014] Referring now to Figs. 3, 4, and 5, the flange 24 is shown to include a locking aperture
30 as part of an interlocking connection to secure adjacent panels 10 together. A
flange 20' of an adjacent panel 10' includes a locking projection 32. As shown in
Fig. 5, the locking projection 32 is disposed within the locking aperture 30. The
diameter of the locking projection is shown as "P", which is smaller than the diameter
of the locking aperture, "A". This size difference permits slight relative movement
between adjoining panels 10 and 10' to allow, for example, 1) panel shifting during
installation, 2) thermal expansion and contraction, and 3) manufacturing tolerance
allowance. In the illustrated embodiment, flange 18 does not include a locking projection
or aperture 30, 32. However, in some embodiments all flanges 18, 20, 22, and 24 may
include locking apertures and/or projections. In other embodiments, none of the flanges
may have locking apertures and projections.
[0015] Some of the flanges include a standout spacer 34, such as are shown in Figs. 4 and
5 as part of flanges 20, and 20'. The standout spacer 34 is positioned along portions
of the transition between the flange 20' and at least one of the top surface 12 and
the bottom surface 26. The standout spacer 34 establishes a gap 36 between adjacent
panels to permit water to flow from the top surface 12 and exit the panel 10. The
standout spacer 34 and the resulting gap also permit thermal expansion and contraction
between adjacent panels while maintaining a consistent top surface plane. Alternatively,
any or all flanges may include standout spacers 34 disposed along the adjoining edges
of panels 10 and 10', if desired. The flanges may have standout spacers 34 positioned
at transition areas along the offset between any of the flanges and the top or bottom
surfaces 12 and 26.
[0016] Referring now to Figs. 6 and 7 there is illustrated an enlarged view of the projections
28, configured as shock absorbing projections. The sides of adjacent projections 28
define a bottom channel 38. The bottom channels 38 are connected to the top drainage
channels 14 by the drain holes 16. The bottom channels 38 permit water to flow from
the top surface 12 through the drain holes 16 and into the ground or other substrate
below the panel 10. In one embodiment, the bottom channels 38 may also store water,
such as at least 25mm of water, for a controlled release into the supporting substrate
below. This slower water release prevents erosion and potential sink holes and depressions
from an over-saturated support substrate. The channels 38 also provide room for the
projections to deflect and absorb impact energy, as will be explained below. Additionally,
the bottom channels 38 also provide an insulating effect from the trapped air to inhibit
or minimize frost penetration under certain ambient conditions.
[0017] The shock absorbing projections 28 are illustrated as having trapezoidal sides and
generally square cross sections. However, any geometric cross sectional shape may
be used, such as round, oval, triangular, rectangular, and hexagonal. Additionally,
the sides may be tapered in any manner, such as a frusto-conical shape, and to any
degree suitable to provide a proper resilient characteristic for impact absorption.
The projections 28 are shown having two absorption stages or zones 40 and 42. A first
stage 40 includes a truncated surface 44 that is configured to support the panel 10
on the substrate or ground. The end of the first stage 40 may alternatively be rounded
rather than a flat, truncated surface. In another alternative embodiment, the end
of the first stage 40 may be pointed in order to be partially embedded in the substrate
layer. A second stage or zone 42 is disposed between the bottom side 26 and the first
stage 40. The second stage 42 is larger in cross section and volume than the first
stage 40. Thus, the second stage 42 has a stiffer spring rate and response characteristic
than that of the first stage 40. This is due to the larger area over which the applied
load is spread. In another embodiment, the first stage 40 may be formed with an internal
void, a dispersed porosity, or a reduced density (not shown) to provide a softer spring
rate characteristic. In yet another embodiment, the first stage 40 may be formed from
a different material having a different spring rate characteristic by virtue of the
different material properties. The first stage 40 may be bonded, integrally molded,
or otherwise attached to the second stage 42. Though the first and second stages 40
and 42 are illustrated as two distinct zones where the first stage 40 is located on
a larger area side of the second stage 42, such is not required. The first and second
stages 40 and 42 may be two zones having constant or smooth wall sides where the two
zones are defined by a volume difference that establishes the differing spring rates.
Alternatively, the projections 28 may have a general spring rate gradient over the
entire projection length between the truncated end 44 and the bottom surface 26.
[0018] Referring to Figs. 8A and 8B, the deflection reaction of the projection 28 is illustrated
schematically. As shown in Fig. 8A, a load "f' is applied onto the top surface 12
representing a lightly applied impact load. The first stage 40 is compressed by an
amount L1 under the load f and deflects outwardly into the channel 38, as shown by
a deflected first stage schematic 40'. The second stage 42 may deflect somewhat under
the load f but such a deflection would be substantially less than the first stage
deflection 40'. As shown in Fig. 8B, a larger impact load "F" is applied to the top
surface 12. The first and second stages 40 and 42 are compressed by an amount L2 under
the load F, where the first stage 40 is compressed more than the second stage 42.
The first stage 40 deflects outwardly to a deflected shape 40". The second stage 42
is also deflected outwardly to a deflected shape 42". Thus, the first and second stages
40 and 42 progressively deflect as springs in series that exhibit different relative
spring rates. These deflected shapes 40', 40", and 42" are generally the shapes exhibited
when an axial compressive load is applied to the top surface. The first and second
stages 40 and 42 may also bend by different amounts in response to a glancing blow
or shearing force applied at an angle relative to the top surface 12.
[0019] The projections 28 are also arranged and configured to distribute the impact load
over a larger surface area of the panel 10. As the panel 10 is subjected to an impact
load, either from the small load f or the larger load F, the projections deflect in
a gradient over a larger area than the area over which the load is applied. For example,
as the panel reacts to the large impact load F, the projections immediately under
the applied load may behave as shown in Fig. 8B. As the distance increases away from
the applied load F, the projections 28 will exhibit deflections resembling those of
Fig. 8A. Thus, the projections 28 form a deflection gradient over a larger area than
the area of the applied load. This larger area includes areas having deflections of
both first and second stages 40 and 42 and areas having deflections of substantially
only the first stage 40. Thus, under a severe impact, for example, in addition to
the compression of the material in the area of the load, the first stage 40 (i.e.,
the smaller portions) of the projections compress over a wider area than the are of
the point of impact. This load distribution creates an area elastic system capable
of distributing energy absorption over a wide area. This produces significant critical
fall heights, as explained below. This mechanical behavior of the projections 28 may
also occur with tapered projections of other geometries that are wider at the top
than at the bottom (i.e., upside down cones).
[0020] Referring now to Fig. 9 there is illustrated another embodiment of a panel 100 having
projections 128 that exhibit a telescopic deflection characteristic. A first stage
140 of the projection 128 is deflected linearly into the second stage 142. During
an initial portion of an impact load, the first stage 140 compresses such that the
material density increases from an original state to a compressed state. A dense zone
140a may progress from a portion of the first stage 140 to the entire first stage.
As the impact load increases, the first stage pushes against and collapses into the
second stage 142. The second stage 142 compresses and permits the first stage to linearly
compress into the second stage 142 similarly to the action of a piston within a cylinder.
A second stage dense zone 142a may likewise progress from a portion of the second
stage to the entire second stage. Alternatively, the dense zones 140a and 142a may
compress proportionally across the entire projection 128.
[0021] The softness for impact absorption of the panel 100 to protect the users, such as
children, during falls or other impacts is a design consideration. Impact energy absorption
for fall mitigation structures, for example children's playground surfaces, is measured
using HIC (head injury criterion). The head injury criterion (HIC) is used internationally
and provides a relatively comparable numerical indicator based on testing. HIC test
result scores of 1000 or less are generally considered to be in a safe range. The
value of critical fall height, expressed in meters, is a test drop height that generates
an HIC value of 1000. For example, to be within the safe zone, playground equipment
heights should kept at or lower than the critical fall height of the base surface
composition. The requirement for critical fall height based on HIC test values in
playground applications may be different from the requirement for critical fall heights
in athletic fields and similar facilities. Also, the HIC/critical fall height will
vary based on the supporting substrate characteristics. In one embodiment, the panel
10 or the panel 100 may be configured to provide a 2.5m critical fall height over
concrete, when tested as a component of a playground surface, and a 2.7m critical
fall height over concrete in combination with a low pile (22mm) artificial turf partially
filled with sand. In another embodiment, the panel 10 or the panel 100 may provide
a 3.0m critical fall height over a compacted sand base in combination with a low pile
(22mm) artificial turf partially filled with sand. By comparison, conventional athletic
field underlayment layers are configured to provide only half of these critical fall
height values.
[0022] These HIC/critical fall height characteristic and figures are provided for comparison
purposes only. The panel 10 or the panel 100 may be configured to absorb more or less
energy depending on the application, such as swings, monkey bars, parallel bars, vertical
and horizontal ladders, along with the ages of the intended users. In one embodiment,
the projections 28 or 128 may have a first stage height range of 10-15mm and a second
stage height range of 15-25mm. In another embodiment, the projections 28 or 128 may
be configured to be in a range of approximately 12- 13mm in height for the first stage
and 19-20mm in height for the second stage in order to achieve the above referenced
HIC figures. The panel 10 or the panel 100 may be made of any suitable material, such
as for example, a polymer material. In one embodiment, the panel 10 or 100 is a molded
polypropylene panel. However, the panel may be formed from other polyolefin materials.
[0023] The panels 10 or 100 may be assembled and covered with any suitable covering, such
as for example, artificial turf, rubber or polymer mats, short pile carpeting, particulate
infill, or chips such as wood chips or ground rubber chips.
[0024] The principle and mode of operation of this invention have been explained and illustrated
in its preferred embodiment. However, it must be understood that this invention may
be practiced otherwise than as specifically explained and illustrated without departing
from its spirit or scope.
[0025] Further embodiments of the claimed subject-matter are explained with the help of
the following examples:
Examples
[0026]
- 1. An impact absorption panel having a top side and a bottom surface, the top surface
including a plurality of drainage channels that are in fluid communication with a
plurality of drain holes, the plurality of drain holes connecting the top surface
drainage channels with a plurality of bottom surface channels, the bottom surface
channels being defined by sides of a plurality of adjacent projections disposed across
the bottom surface.
- 2. The impact absorption panel of example 1 wherein the adjacent projections each
have a first spring rate characteristic and a second spring rate characteristic wherein
the first spring rate characteristic provides for more deflection under load than
the second spring rate characteristic.
- 3. The impact absorption panel of example 2 wherein the first spring rate characteristic
of the projections is part of a first stage and the second spring rate characteristic
is part of a second stage.
- 4. The impact absorption panel of example 3 wherein the first stage has a smaller
volume of material than the second stage.
- 5. The impact absorption panel of example 3 wherein the first stage is formed from
a different material than the second stage.
- 6. The impact absorption panel of example 3 wherein the first and second stages of
the projections deflect as springs in series.
- 7. The impact absorption panel of example 3 wherein the first stage is configured
to collapse initially when subjected to an impact load, the second stage is configured
to provide greater resistance to the impact load than the first stage, and a panel
section is defined between the top surface and the bottom surface, the panel section
being configured to provide greater resistance to the impact load than the first and
second stages, the projections further including truncated ends.
- 8. The impact absorption panel of example 7 wherein the second stage is configured
to be dimensionally larger than the first stage.
- 9. The impact absorption panel of example 7 wherein the top surface includes a three
dimensional surface texture that creates friction to retain a covering layer and wherein
a portion of the bottom surface is generally coplanar with the truncated ends of adjacent
projections forming a coplanar bottom surface portion such that the coplanar bottom
surface portion is configured to provide a structural support surface having a substantial
resistance to deflection under load compared with the first and second stages.
- 10. The impact absorption panel of example 7 wherein the top surface includes a molded
topography configured to facilitate drainage.
- 11. The impact absorption panel of example 7 wherein at least one flange extends from
the panel section, the flange being configured to overlap with a mating panel flange
such that the top surface and the bottom surface of one panel are generally continuous
with the top surface and bottom surface of the adjacent panels.
- 12. The impact absorption panel of example 7 wherein at least one flange extends from
the panel section, the flange being configured to overlap with a mating panel flange
and further configured to compensate for thermal expansion.
- 13. The impact absorption panel of example 7 wherein the plurality of projections
include an open bottom area between projections configured to store water in a rain
event.
- 14. The impact absorption panel of example 13 wherein the open bottom area between
projections can store up to at least 25mm of water.
- 15. The impact absorption panel of example 13 wherein the open bottom area between
projections is configured to create a dead insulating airspace to inhibit frost penetration.
- 16. An impact absorption panel system comprising:
a first panel having a top surface, a bottom surface, a first edge having a flange
that is offset from the top surface and a second edge having a flange that is offset
from the bottom surface, a plurality of projections are disposed across the bottom
surface, the projections having a first spring rate characteristic and a second spring
rate characteristic; and
a second panel having a top surface, a bottom surface, a first edge having a flange
that is offset from the top surface and a second edge having a flange that is offset
from the bottom surface, a plurality of projections are disposed across the bottom
surface, the projections having a first spring rate characteristic and a second spring
rate characteristic, wherein one of the second panel first edge flange and second
edge flange engages one of the first panel second edge flange and the first panel
first edge flange to form a base layer configured to have a generally continuously
flat top surface.
- 17. The impact absorption panel system of example 16 wherein the first edge flange
of the first and second panels has one of a locking aperture and a locking projection
and the second edge flange of the first and second panels has the other of a locking
aperture and a locking projection.
- 18. The impact absorption panel system of claim 16 wherein one of an artificial turf,
an athletic mat, a carpet, and a particulate layer is disposed over the cooperating
first and second panels.
- 19. An impact absorption panel comprising:
a top surface having a three dimensional textured surface and a plurality of intersecting
drainage channels;
a bottom surface spaced apart from the top surface and defining a panel section therebetween;
a plurality of projections disposed across at least a portion of the bottom surface,
the projections having a first stage that defines a first spring rate characteristic
and a second stage defining a second spring rate characteristic wherein the first
spring rate characteristic provides for more deflection under load than the second
spring rate characteristic, the plurality of projections cooperating during deflection
under load such that the adjacent projections provide a load absorption gradient over
a larger area than the area directly loaded, the first stage having a smaller volume
of material than the second stage, and wherein adjacent projections define a bottom
surface channel to form a plurality of intersecting bottom surface channels; and
a plurality of drain holes connecting the top surface drainage channels with the plurality
of bottom surface channels at the drainage channel intersections.
- 20. The impact absorption panel of example 19 wherein the first stage is configured
to collapse initially when subjected to an impact load, the second stage is configured
to provide greater resistance to the impact load than the first stage, and the panel
section is configured to provide greater resistance to the impact load than the first
and second stages, the first stage being further configured to compress and telescopically
deflect into the second stage, and wherein a portion of the bottom surface is generally
coplanar with the truncated ends of adjacent projections such that the coplanar bottom
surface portion is configured to provide a substantial resistance to deflection under
load compared with the first and second stages.
1. An impact absorption panel (10, 100) having a top surface (12) and a bottom surface
(26), especially for use with paving elements, the top surface (12) including a plurality
of drainage channels (14) and a three dimensional textured surface, wherein the drainage
channels (14)are in fluid communication with a plurality of drain holes (16), the
plurality of drain holes (16) connecting the drainage channels (14) with a plurality
of bottom surface channels (38), the channels (14, 38)being defined by sides of a
plurality of adjacent projections , the projections forming a shock absorbing structure
providing a load distribution that creates an area elastic system capable of distributing
energy absorption over a wide area.
2. The impact absorption panel of claim 1, wherein the adjacent projections (28, 128)
each have a first spring rate characteristic (40, 140) and a second spring rate characteristic
(42, 142) wherein the first spring rate characteristic (40, 140) provides for more
deflection under load than the second spring rate characteristic (42, 142).
3. The impact absorption panel of claim 2 wherein the first spring rate characteristic
of the projections (28, 128) is part of a first stage (40, 140) and the second spring
rate characteristic is part of a second stage (42, 142).
4. The impact absorption panel of claim 3 wherein the first stage (40, 140) has a smaller
volume of material than the second stage (42, 142).
5. The impact absorption panel of claim 3 wherein the first stage (40, 140) is formed
from a different material than the second stage (42, 142).
6. The impact absorption panel of claim 3 wherein the first (40, 140) and second (42,
142) stages of the projections (28, 128) deflect as springs in series.
7. The impact absorption panel of claim 3 wherein the first stage (40) is configured
to collapse initially when subjected to an impact load, the second stage (42) is configured
to provide greater resistance to the impact load than the first stage (40), and a
panel section (27) is defined between the top surface (12) and the bottom surface
(26), the panel section (27) being configured to provide greater resistance to the
impact load than the first (40) and second (42) stages, the projections (28) further
including truncated ends (44).
8. The impact absorption panel of claim 7 wherein the second stage (42) is configured
to be dimensionally larger than the first stage (40).
9. The impact absorption panel of claim 7 wherein the three dimensional surface texture
creates friction to retain a covering layer and wherein a portion of the bottom surface
(26) is generally coplanar with the truncated ends (44) of adjacent projections (28)
forming a coplanar bottom surface portion such that the coplanar bottom surface portion
is configured to provide a structural support surface having a substantial resistance
to deflection under load compared with the first (40) and second (42) stages.
10. The impact absorption panel of claim 7 wherein the top surface (12) includes a molded
topography configured to facilitate drainage.
11. The impact absorption panel of claim 7 wherein at least one flange (18, 20, 22, 24)
extends from the panel section (27), the flange (18, 20, 22, 24) being configured
to overlap with a mating panel flange (18, 20, 22, 24) such that the top surface (12)
and the bottom surface (26) of one panel (10) are generally continuous with the top
surface (12) and bottom surface (26) of the adjacent panels (10).
12. The impact absorption panel of claim 7 wherein at least one flange (18, 20, 22, 24)
extends from the panel section (27), the flange (18, 20, 22, 24) being configured
to overlap with a mating panel flange (18, 20, 22, 24) and further configured to compensate
for thermal expansion.
13. The impact absorption panel of claim 7 wherein the plurality of projections (28) include
an open bottom area (38) between projections (28) configured to store water in a rain
event.
14. The impact absorption panel of claim 13 wherein the open bottom area between projections
(28) can store up to at least 25mm of water.
15. The impact absorption panel of claim 13 wherein the open bottom area between projections
(28) is configured to create a dead insulating airspace to inhibit frost penetration.