U.S. patent application number 12/468175 was filed with the patent office on 2009-11-19 for footwear with independent suspension and protection.
Invention is credited to Alexander Dardinski, Peter Dillon, David L. Vattes.
Application Number | 20090282700 12/468175 |
Document ID | / |
Family ID | 38197828 |
Filed Date | 2009-11-19 |
United States Patent
Application |
20090282700 |
Kind Code |
A1 |
Dillon; Peter ; et
al. |
November 19, 2009 |
FOOTWEAR WITH INDEPENDENT SUSPENSION AND PROTECTION
Abstract
An article of footwear having an upper and a sole is disclosed.
The sole of the article of footwear includes a midsole having a
support portion and a plurality of projections extending from the
support portion. The sole of the article of footwear also includes
a plate contacting the support portion having a body positioned in
an area between the plurality of projections. The plate further
includes a plurality of openings which correspond to the plurality
of projections and allow the projections to extend below the body
of the plate. The plate further includes a plurality of cantilever
elements extending on at least one side and on the bottom of each
of the plurality of projections. The projections and the
corresponding cantilever elements interact with one another to form
a plurality of lugs located on the sole of the article of
footwear.
Inventors: |
Dillon; Peter; (Topsfield,
MA) ; Dardinski; Alexander; (Newburyport, MA)
; Vattes; David L.; (Londonderry, NH) |
Correspondence
Address: |
STRATEGIC PATENTS P.C..
C/O PORTFOLIOIP, P.O. BOX 52050
MINNEAPOLIS
MN
55402
US
|
Family ID: |
38197828 |
Appl. No.: |
12/468175 |
Filed: |
May 19, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
11433036 |
May 12, 2006 |
7549236 |
|
|
12468175 |
|
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|
|
60781126 |
Mar 9, 2006 |
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Current U.S.
Class: |
36/88 ; 36/102;
36/28 |
Current CPC
Class: |
A43B 5/06 20130101; A43B
13/24 20130101; A43B 13/183 20130101; A43B 13/184 20130101 |
Class at
Publication: |
36/88 ; 36/102;
36/28 |
International
Class: |
A43B 7/14 20060101
A43B007/14; A43B 1/00 20060101 A43B001/00; A43B 13/18 20060101
A43B013/18 |
Claims
1. An article of footwear comprising an upper and a sole, the sole
including: a plate having a body with a first surface, a second
surface, and a plurality of spaced apart cantilever elements
extending from the first surface of the plate in a direction away
from the second surface and having ground contacting portions
spaced apart from the body of the plate.
2. The article of claim 1 further including a midsole having a
support portion with a first and second surface, the first surface
thereof substantially contacting the second surface of the body of
the plate.
3. An article of footwear comprising: an upper for securing a foot
of a wearer; and a sole including: a support portion having a first
surface and a second surface, at least a portion of the first
surface being attached to the upper; and suspension means attached
to the support portion for providing portions of the sole which
engage a ground surface and which react independently to forces
applied to the sole.
4. The article of claim 3 wherein the suspension means includes a
plurality of lugs, each of the lugs including cantilever means for
providing directional motion to the suspension means and projection
means for providing support for the cantilever means.
5. The article of claim 4 wherein the projection means are
integrally formed with the support portion.
6. An article of footwear for use by a wearer comprising: an upper
member operable to engage a foot of the wearer; and a sole
connected to the upper member, the sole comprising a plurality of
stability members operable to engage a ground surface and to
cantilever independently in response to ground forces so as to
provide stability for the wearer.
7. The article of claim 6 wherein a first one of the plurality of
stability members cantilevers in response to a first object, and
wherein a second one of the plurality of stability members
cantilevers in response to a second object.
8. An article of footwear for use by a wearer comprising a sole
having a plurality of discreet, resilient stability members for
contacting a ground surface, the stability members being operable
to absorb forces and attenuate instability caused by irregularities
in the ground surface.
9. The article of footwear of claim 8 wherein each of the stability
members defines a ground contacting portion, wherein said stability
members have a predetermined maximum depth of compression, and
wherein said stability members attenuate instability by
independently compressing such that the ground contacting portions
thereof contour to the ground surface.
10. The article of footwear of claim 8 wherein the stability
members reduce instability by attenuating inversion and eversion of
the ankle joint of the wearer.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of the following
application, each of which is hereby incorporated by reference in
its entirety: U.S. patent application Ser. No. 11/433,036 filed May
12, 2006 which claims the benefit U.S. Prov. Patent Application
60/781,126 filed Mar. 9, 2006.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to articles of
footwear, and in particular to articles of footwear having an
outsole having improved force distribution and stability on uneven
surfaces or terrain.
[0003] Most conventional footwear is designed to deflect ground
forces by using hard, rigid bottoms. This causes the wearer to
absorb much of the force and impact of any uneven terrain
underfoot, leading to instability, bruising and risk of injury,
including for example, the turning of an ankle. Typical shoe
construction, particularly with respect to athletic shoe
construction such as sneakers and hiking boots, includes an upper
and a sole unit. The sole unit can include multiple layers of
material such as foam and/or rubber. Typically these shoes have a
hard outsole to withstand abrasion and a soft midsole layer to
provide absorption of ground forces. A common problem in footwear,
in particular athletic footwear, is that although a softer midsole
is desirable for absorption of ground forces, too soft of a midsole
allows the heel to displace into the midsole under load conditions.
Excessive displacement of the heel often leads to overpronation,
causing instability and motion control issues. Such soles typically
have a ground contacting portion in the form of an outsole with a
number of traction elements thereon, which may project outwardly
from the midsole portion of the shoe but, nevertheless, add only
minimal force attenuation or cushioning, the bulk of which are
dealt with by the midsole of the shoe. In this arrangement, when an
object is stepped on or when uneven terrain is encountered, the
hard outsole causes the bottom portion of the shoe to react as a
unitary structure and often leads to instability when in contact
with uneven surfaces. This also reduces the amount of ground
contact for the shoe, which can cause traction problems.
Furthermore, such a design leads to problematic levels of point
loading when objects are encountered. Point loading occurs when
force from an object is transferred to the foot of the wearer of
the shoe such that the force is concentrated in a small area. Point
loading can cause the portion of the sole with which the foot makes
contact (typically an insole) to deflect upwardly into the foot,
which can cause pain and discomfort for the wearer. This can also
cause bruising under foot and can adversely affect whole body
stability of the wearer.
[0004] Problems with stability and point loading are particularly
prevalent in what is generally known as trail running. Trail
running is a type of running that differs markedly from road
running and track running. Road running and track running often
take place on flat or smoothly inclined surfaces. In contrast,
trail running generally takes place on hiking trails, most commonly
on single track trails, although fire roads are not uncommon. A
distinguishing characteristic of such trails is that they are often
inaccessible by road except at the trail heads. The trails tend to
traverse varying terrain, hills, mountains, deserts, forests, etc.
Narrow traverses are common. Likewise, steep inclines or rough
terrain sometimes may require hiking or "scrambling." Runners
participating in trail runs must often descend these same steep
grades. It is typical for trail runs to ascend and descend
thousands of feet. Trail running often takes place in both
organized trail races, and as a recreational activity. Common
distances in races are 10 km, 20 km, 30 km, marathon (42 km), 50
km, and 50 miles. Anything over marathon distance is considered an
Ultramarathon or "Ultra," which may range up to the 100 mile mark
(and beyond). Trail running has become increasingly popular around
the world.
[0005] With regard to footwear, trail runners have specific and
unique needs as opposed to other kinds of runners such as road
runners and track runners. By way of example only, road and track
runners may prioritize shock attenuation and pronation control in
their footwear to deal with terrain like tracks and road surfaces.
Trail runners, by contrast, are often challenged to stay upright
while running on unpredictable terrain. They are looking for
balance of the entire body, not just pronation control. During
locomotion, the foot naturally moves through various amounts of
what is known in the art as pronation and supination. Such movement
is described in general in the article entitled "Standard Test
Method For Comparison of Rearfoot Motion Control Properties of
Running Shoes," published by ASTM International in August, 1998,
the entirety of which is incorporated by reference herein. Although
unique to each individual, many people have an average maximum
pronation angle of between 7 and 11 degrees during locomotion on a
flat surface. Rear foot angle .THETA. (as shown in FIG. 31) is
generally proportional to pronation angle and is typically on the
order of approximately 3 degrees. The amount of pronation and/or
supination experienced during trail running tends to vary among a
wider range than during road or track running due to the uneven
surface of the trails and the frequency with which objects are
encountered underfoot, both of which influence the angle of the
foot relative to the lower leg. When an object or uneven terrain
causes pronation or supination to increase beyond the average
maximum range for a given subject, instability begins to occur. If,
for example, rear foot angle begins to approach a pronation angle
of above about 20 degrees, medial motion of the knee will occur. By
further example, if the rear foot angle begins to approach a
pronation angle of about 30 degrees, excess motion of the hip can
occur, which results in movement of the pelvis. Excess movement of
the ankle, knee and hip joints may result in upper body
instability. Instability contributes to loss of control or balance.
In trail running, there is also a concern regarding protection from
bruising under foot which may be caused by repeated impacts with
rocks, roots and other irregularities with uneven terrain.
[0006] Of additional concern for trail runners is the need for
moisture management, lightweight design, in-shoe security that
minimizes anterior-posterior movement when running either uphill or
downhill and medial-lateral movement while traversing a slope, and
traction for a variety of surfaces including irregular surfaces and
wet and dry terrain. Current footwear does not adequately address
such trail running requirements.
[0007] It is therefore desired to provide articles of footwear that
can minimize instability and that have soles which can provide the
desired force attenuation and traction properties for trail
running. These structures may also be beneficial for other forms of
conventional running or hiking and in other situations, where
objects may also be encountered and inclement conditions can cause
problems relating to stability, traction and comfort. Such
configurations should further provide lightweight sole designs and
should be compatible with various footwear uppers.
SUMMARY OF THE INVENTION
[0008] This invention replaces a conventional midsole/outsole with
an integrated support portion that has multiple independent
cantilevered elements. This integrated bottom supports the foot and
body during compression thereof and better distributes ground
forces by adapting to uneven terrain, therefore greatly increasing
stability and motion control, and acting as a return spring. The
present invention relates to an article of footwear including an
upper for securing a foot of a wearer and a sole. The sole includes
a midsole with a support portion having a first surface coupled to
the upper and a second surface. The second surface further has a
plurality of projections extending therefrom in a direction away
from the first surface, each projection having a side and a bottom.
The sole further includes a plate having a body portion contacting
the at least a portion of the second surface of the support portion
and having a plurality of cantilever elements contacting at least
the side and the bottom of corresponding ones of the plurality of
projections. Preferably, the projections and the corresponding
cantilever elements interact with one another to form a plurality
of lugs located on the bottom of the article of footwear. In a
preferred embodiment, the article of footwear further includes an
outsole affixed to at least a portion of the lug, preferably on the
cantilever element so as to form a ground-engaging surface.
[0009] In a preferred embodiment of the present invention, each of
the plurality of projections extends below the support portion of
the midsole at a distance of at least 5 mm. Further the projections
preferably extend below the support portion of the midsole at a
distance of less than about 21 mm. More preferably, the projections
extend below the support portion of the midsole at a distance of
about 13 mm. Further, the lugs preferably extend below the support
portion of the midsole by at least 7 mm. It is also preferred that
the lugs extend below the support portion of the midsole by less
than 23 mm. Preferably, the lugs extend below the support portion
of the midsole by about 15 mm. However, the desired distance by
which the lugs extend below the support portion may vary by the
location of the individual lugs on the sole of the shoe. For
example, some lugs may be located near the toe region of the sole
and may project at a lesser distance below the support portion than
do those located near the midfoot portion of the sole. Throughout
this disclosure, the distance below the support portion by which a
lug (or lugs) project may be referred to as the "height" of the
lug. Further, it is preferred that at least one of the plurality of
lugs has a width of between 12 mm and 32 mm in the medial-lateral
direction and a length of between 5 mm and 15 mm in the
anterior-posterior direction. Both the length and width of the lugs
in both the medial-lateral and anterior-posterior directions may
vary depending on the location and orientation of the lugs within
the shoe sole. Although it may be preferred to have the
above-referenced height and width measurements, it is understood by
those skilled in the art that measurements lesser or greater than
those referenced may be applied to achieve a shoe sole as described
above and is within the scope of this invention.
[0010] Preferably, the midsole is formed from a foam such as a
thermoformable foam, which may be polyurethane (PU). Alternatively,
the midsole may be formed from ethyl vinyl acetate (EVA), polyester
or other suitable foams. The midsole is preferably made from a
material having a hardness, or durometer, of about 52 C on what is
known in the art as an Asker C scale. In one alternative, the
midsole has a hardness of at least about 45 C. In another
alternative, the midsole has a hardness of less than about 60
C.
[0011] Preferably, the plate is made from a plastic such as a
thermoformable plastic. The thermoformable plastic is preferably a
nylon and polyether blend, such as PEBAX.RTM. brand thermoplastic
elastomers. Alternatively, the plate may be formed from
thermoplastic polyurethane (TPU), nylon, polyether and/or polyester
blends, a composite material containing carbon fiber or fiberglass,
plastics such as PVC or other thermoplastic engineering materials.
Desirably, the plate is made from a material having a hardness of
between 50 D and 70 D on what is known in the art as a shore D
scale, and more preferably from a material having a hardness on the
order of 60 D.
[0012] Preferably, the outsole is formed from a rubber material,
which can include traction rubber, PU, EVA, TPU, thermoplastic
rubber (TPR), or a rubberized textile material. Furthermore, the
outsole may contain different materials in different areas thereof,
such as the heel, toe or other ground-contacting surfaces.
Optionally, portions of the outsole may have multiple layers and/or
regions of the same or different materials. The material used to
form the outsole may vary in hardness throughout the various
sections of the outsole. Preferably, the hardness of the material
used for the outsole is between 45 A and 75 A on what is known in
the art as a Shore A scale. Variation in the hardness of the
outsole material will be understood by those having reasonable
skill in the art upon reading this disclosure. Preferably, the
outsole has a thickness of at least about 1 mm. Further, it is
preferred that the outsole has a thickness of less than 6 mm.
Preferably, the thickness of outsole is about 4 mm. The cantilever
elements of the present invention may include a side portion and a
bottom portion. In one embodiment of the present invention, the
outsole is affixed to at least the bottom portion of respective
cantilever elements. In a further embodiment, the outsole is
affixed to at least the bottom and side portions of respective
cantilever elements. The outsole may be further affixed to the body
portion of the plate. In a further embodiment, the outsole is
further affixed to at least a portion of one of the plurality of
projections which is exposed between the cantilever element and the
body portion of the plate.
[0013] In a preferred embodiment of the present invention, at least
one of the plurality of projections includes a surface which is
oriented in the anterior direction. In such an arrangement it is
preferable that the plate extends to cover at least a portion of
this face to form a lug therebetween. Preferably such a lug is
located in the forefoot region of the bottom of the article of
footwear, but such a lug can be located in or near the heel region.
Further, others of the plurality of projections may include a
surface which is oriented in the posterior direction. The plate
preferably extends to cover at least a portion of this face to form
a lug therebetween. Preferably, such a lug is located toward the
heel region of the bottom of the article of footwear, but such a
lug may be located in the forefoot region.
[0014] It is possible to employ one or more projections in any
configuration, orientation or pattern. Preferably, the midsole
includes at least two projections spaced apart relative to each
other in an anterior-posterior alignment. It is further preferable
for midsole to include at least two projections spaced apart
relative to each other in a medial-lateral arrangement. More
preferably, the midsole can include at least two groups of
projections spaced apart from each other in an anterior-posterior
alignment. Each group of lugs preferably includes at least two
projections spaced apart relative to each other in a medial-lateral
arrangement. Preferably, a portion of the plate extends to cover a
side portion and a bottom portion of each of the lugs used in such
an arrangement. Even more preferably, the midsole can include at
least three groups of projections spaced apart from each other in
an anterior-posterior direction. Each group of lugs preferably
includes at least three projections spaced apart relative to each
other in a medial-lateral direction.
[0015] In an alternative embodiment of the present invention, at
least one projection extends across substantially the entire sole
in a medial-lateral direction. Preferably, the sole includes at
least three of these projections. Such a projection can be either
substantially straight in a medial lateral direction or can have a
medial portion, a lateral portion and a middle portion, the middle
portion being located toward an anterior portion of the shoe
relative to the medial and lateral portions thereof.
[0016] An alternative embodiment of the present invention relates
to an article of footwear including an upper and a sole. The sole
includes a plate having a body portion with a plurality of
spaced-apart openings, each of the openings having an edge
therealong, and a plurality of cantilever elements, each of the
cantilever elements corresponding to one of the openings and
extending from the edge thereof below the body portion. The sole
further includes a midsole having a support portion substantially
contacting an upper surface of the body portion of the plate and a
plurality of projections corresponding to the openings of the plate
and extending therethrough, each of the projections contacting a
respective one of the cantilever elements so as to form a plurality
of lugs. Further, each of the plurality of lugs forms a ground
contacting portion, the body portion of the plate being spaced
apart from the ground contacting portions of the plurality of
lugs.
[0017] A further embodiment of the present invention relates to an
article of footwear having an upper and a sole. The sole includes a
plate having a body with a first surface, a second surface, and a
plurality of spaced apart cantilever elements extending from the
first surface of the plate in a direction away from the second
surface and forming a ground contacting portion spaced apart from
the body of the plate. The sole further includes a midsole having a
support portion with a first surface and a second surface, the
first surface thereof substantially contacting an upper surface of
the body of the plate.
[0018] A still further embodiment of the present invention relates
to an article of footwear including an upper for securing a foot of
a wearer and a sole. The sole includes a support portion having a
first surface and a second surface, at least a portion of the first
surface being attached to the upper. The sole further includes
suspension means attached to the support portion for providing
portions of the sole which engage a ground surface and which react
independently to forces applied to the sole. The suspension means
may include a plurality of lugs, each of the lugs having cantilever
means for providing directional motion to the suspension means and
cushioning means for providing support for the cantilever means.
Further the cushioning means may be integrally formed with the
support portion.
[0019] A further embodiment of the present invention relates to an
article of footwear for use by a wearer having an upper member
operable to engage a foot of the wearer and a sole connected to the
upper member. The sole includes a plurality of stability members
operable to engage a ground surface and to cantilever independently
in response to ground forces so as to provide stability for the
wearer. A first one of the plurality of stability members may
cantilever in response to a first object, and a second one of the
plurality of stability members may cantilever in response to a
second object.
[0020] A still further embodiment of the present invention relates
to an article of footwear for use by a wearer including a sole
having a plurality of discreet, resilient stability members for
contacting a ground surface. The stability members are operable to
absorb forces and attenuate instability caused by irregularities in
the ground surface. Each of the stability members may define a
ground contacting portion, wherein the stability members each have
a predetermined maximum depth of compression, and wherein the
stability members attenuate instability by independently
compressing up to the maximum depth of compression such that the
ground contacting portions thereof contour to the ground surface.
The stability members may reduce instability by attenuating
inversion and eversion of the ankle joint of the wearer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The present invention will be better understood on reading
the following detailed description of non-limiting embodiments
thereof, and on examining the accompanying drawings, in which:
[0022] FIG. 1 is an elevation view of an article of footwear
according to an embodiment of the present invention;
[0023] FIG. 2 is an elevation view of an article of footwear
according to an embodiment of the present invention;
[0024] FIG. 3 is an elevation view of a sole for an article of
footwear according to an embodiment of the present invention;
[0025] FIG. 4 is a bottom view of an article of footwear according
to an embodiment of the present invention;
[0026] FIG. 5 is an elevation view of a sole for an article of
footwear according to an embodiment of the present invention;
[0027] FIG. 6 is a cross-section view of a sole for an article of
footwear according to an embodiment of the present invention;
[0028] FIG. 7 is a cross-section view of a sole for an article of
footwear according to an embodiment of the present invention;
[0029] FIG. 8 is a cross-section view of a sole for an article of
footwear according to an embodiment of the present invention;
[0030] FIG. 9 is a cross-section view of a sole for an article of
footwear according to an embodiment of the present invention;
[0031] FIG. 10 is a cross-section view of a sole for an article of
footwear according to an embodiment of the present invention;
[0032] FIG. 11 is an elevation view of a sole for an article of
footwear according to an embodiment of the present invention;
[0033] FIG. 12 is a bottom view of an article of footwear according
to an embodiment of the present invention;
[0034] FIGS. 13a-d are cross-section views of a sole for an article
of footwear according to an embodiment of the present
invention;
[0035] FIGS. 14a-b are cross-section views of a sole for an article
of footwear according to an embodiment of the present
invention;
[0036] FIG. 15 is a cross-section view of a sole for an article of
footwear according to an embodiment of the present invention;
[0037] FIG. 16 is a cross-section view of a sole for an article of
footwear according to an embodiment of the present invention;
[0038] FIG. 17 is an assembly view of sole for an article of
footwear according to an embodiment of the present invention;
[0039] FIG. 18 is a top view of a plate for a sole for an article
of footwear according to an embodiment of the present
invention;
[0040] FIG. 19 is an elevation view of a sole for an article of
footwear according to an embodiment of the present invention;
[0041] FIG. 20 is a bottom view of a sole for an article of
footwear according to an embodiment of the present invention;
[0042] FIG. 21 is a cross-section view of a sole for an article of
footwear according to an embodiment of the present invention;
[0043] FIG. 22 is a bottom view of a sole for an article of
footwear according to an embodiment of the present invention;
[0044] FIG. 23 is a flowchart showing a process of making a sole
for an article of footwear according to an embodiment of the
present invention;
[0045] FIG. 24 is a top view of a midsole for an article of
footwear according to an embodiment of the present invention;
[0046] FIG. 25 is a bottom view of a suspension plate for an
article of footwear according to an embodiment of the present
invention;
[0047] FIG. 26 is an elevation view of an article of footwear
according to an embodiment of the present invention;
[0048] FIG. 27 is a bottom view of an article of footwear according
to an embodiment of the present invention;
[0049] FIG. 28 is an elevation view of an article of footwear
according to an embodiment of the present invention;
[0050] FIG. 29 is a bottom view of an article of footwear according
to an embodiment of the present invention;
[0051] FIGS. 30(a)-(c) illustrate supination (inversion), pronation
(eversion) and a neutral position of a wearer's leg and foot;
and
[0052] FIG. 31 is an elevation view of an exemplary lower leg, as
viewed from the posterior direction.
DETAILED DESCRIPTION
[0053] Referring now to the drawings, wherein like reference
numerals represent like elements, there is shown in FIG. 1 an
article of footwear according to an embodiment of the present
invention. The particular article of footwear shown in FIG. 1 is in
the form of an athletic shoe having an upper 12 and a sole 14.
However, it is to be understood that the present invention could be
implemented with any type of footwear, including sandals, boots,
dress shoes, etc. Upper 12 is designed to receive the foot of a
wearer by defining a portion of foot receiving cavity 13 therein.
Upper 12 is structured to securely hold the wearer's foot and, to
the extent possible, maintain the foot in contact with sole 14.
Upper 12 is also preferably designed to provide support for the
foot and to protect the foot from injury. Preferably, upper 12
covers the metatarsal and toe region of the foot as well as the
instep portion and the heel portion of the foot.
[0054] While upper 12 may be of any configuration or style, in a
preferred example upper 12 may comprise a compression molded upper
having a pair of thermoformable foam layers separated by a layer of
another material such as a mesh, leather, non-woven fabric, rubber,
PTFE, etc. Such compression molded uppers are more fully described
in co-pending U.S. patent application Ser. No. 11/362,348, filed
Feb. 24, 2006, entitled "Compression Molded Footwear and Methods of
Manufacture," the entire disclosure of which is hereby incorporated
by reference herein.
[0055] The bottom portion of foot receiving cavity 13 is defined by
insole 15, which is generally structured to support and comfort the
foot of the wearer of shoe 10. Sole 14 is structured to provide
further support as well as protection and traction for the foot of
the wearer and makes contact with the ground underneath shoe 10.
Sole 14 according to an embodiment of the present invention
includes midsole 16, outsole 18 and suspension plate 20. As best
shown in FIG. 17, midsole 16 includes support portion 22, which
contacts and substantially covers the bottom surface of the insole
15 (or the foot, if no insole is present) and provides support and
cushioning for the foot of a wearer. Returning to FIG. 1, midsole
16 further includes toe section 26, heel section 28 and a plurality
of spaced-apart projections 30 which extend away from support
portion 22. Suspension plate 20 includes a body 25 which makes
contact with and substantially covers the bottom surface of support
portion 22. As best shown in FIGS. 17 and 18, suspension plate 20
desirably includes a plurality of openings 27, through which
projections 30 pass and extend below body 25. Cantilever elements
24 are formed in suspension plate 20 and extend therefrom so as to
mate with projections 30 to form a plurality of lugs 17 (see FIG.
1) providing additional support and cushioning for the foot of the
wearer. Outsole 18 is affixed at least to the lowermost portion of
lugs 17 and makes contact with the ground below the shoe 10.
Outsole 18 is adapted to provide cushioning and/or traction for the
wearer of shoe 10, as will be described in detail below.
[0056] Midsole 16 is generally formed from a thermoformable foam,
which is preferably PU. Additional materials which can be used to
form midsole 16 include EVA or other materials known in the art for
such a purpose. The material from which midsole 16 is made should
be selected to provide both cushioning and support for the shoe.
Furthermore, the material used to form midsole 16 is desirably
thermoformable so that the material can be molded into the desired
shape using known molding methods. Midsole 16 can be formed, for
example, either by injection molding or by compression molding,
both of which are known methods for making a foam midsole. With
respect to the particular midsole design of the present invention,
midsole 16 can be compression molded from die-cut blockers made
from PU foam or other suitable materials. In such formation, a
single blocker is cut into the general shape for midsole 16, which
is then compression molded into the desired shape. When such a
process is used, the blocker used to make midsole 16 can be made of
different types of material in different areas corresponding to
specific regions of midsole 16, each possessing different
characteristics such as material hardness or color. This allows
different cushioning, support, force attenuation, or other
properties to be used in different parts of midsole 16.
Additionally, different properties for the midsole material can be
selected to provide desired characteristics for the footwear
depending on the weight of a wearer.
[0057] Suspension plate 20 is preferably made from a thermoformable
plastic material, and more preferably from a nylon and polyether
blend known as PEBAX.RTM. brand thermoplastic elastomers. Such a
material is preferred due to durability, with respect to both its
resistance to abrasion and with respect to its ability to
repeatedly bend or flex within a range acceptable for purposes of
the present disclosure without undergoing significant permanent
deformation or cracking, while being generally lightweight.
Alternatively, suspension plate 20 can be made from TPU, nylon,
polyether or polyester blends such as HYTREL.RTM. brand polyester
elastomers, composite materials containing carbon fiber or
fiberglass in combination with plastics such as polyvinyl chloride
("PVC"). As shown in FIGS. 17 and 18, suspension plate 20 includes
body portion 25, which is structured to mate with and substantially
cover bottom surface 19 (shown in FIG. 17) of midsole 16, including
the areas of support portion 22 between heel portion 28, toe
portion 26 and projections 30. Additionally, support plate 20 forms
cantilever elements 24 which extend along a face of lugs between
the main body of support plate and the lowermost portions thereof,
as well as the lowermost surfaces 19 of heel and toe portions 26,
28 and projections 30. A plurality of openings 27 in suspension
plate 20 allows projections 30 to extend through body portion 25 of
suspension plate 20 and into contact with corresponding cantilever
elements 24 thereof.
[0058] Returning now to FIG. 1, outsole 18 may either be unitary in
structure, or may be made up of separate pieces of material affixed
to support plate 20 in strategic locations thereof. Further,
outsole can have additional layers of material 18a affixed thereto
to provide additional properties, such as traction, for specific
areas of outsole 18. Preferably, outsole is made from what is known
in the art as "traction rubber." Alternative materials for outsole
18 include PU, EVA, TPU, TPR, and rubberized textile materials, or
any combinations therein. Further alternatives for outsole 18
include those known in the art for typical outsole formation. The
material used for outsole should have a hardness of more than 45 A,
but less than 75 A. Preferably, the material hardness for outsole
18 is on the order of 50 A to 60 A. Outsole 18 preferably covers at
least the areas of sole 14 which make contact with the ground, but
can cover additional portions of sole 14 and may cover the entire
bottom surface of sole 14. Further, different areas of outsole 18
can be made from different materials in order to provide desired
traction and/or cushioning properties to various areas of outsole
18. Preferably, outsole 18 covers the ground contacting portions of
lugs 17 as well as heel 28 and toe 26 portions of sole 14.
Additionally, the material for outsole 18 can cover cantilevered
element 24, can extend upwardly around the toe of the shoe, and/or
may cover a portion of the upper 12 in order to provide traction
and protection.
[0059] Projections 30 of midsole 14 mate and interact with
cantilever elements 24 of suspension plate 20 to form lugs 17. Lugs
17 are structured to react independently to the forces applied to
sole 14, particularly forces from objects which may be encountered
while running on a trail having irregularities in the ground
surface thereof. Such irregularities of the ground surface may
include uneven surfaces or terrain, as well as objects such as
rocks, branches, roots, debris, etc. With a conventional sole the
sole absorbs some of the force, transferring the remainder to the
foot of the wearer.
[0060] In the present embodiment the independent compression or
flexion of the individual lugs 17 allows for both increased
traction and stability for the footwear wearer. When traditional
footwear, with an outsole formed from a single layer of rubber,
encounters objects or uneven terrain, the footwear reacts as a
monolithic structure, wherein the encountered ground force is only
partially absorbed by deflection of the footwear sole, the
remainder of the force being transferred to the foot and lower
extremity of the wearer. As large ground reaction forces are caused
by the footwear sole contacting an object or uneven terrain, which
does not measurably compress underfoot, the force applied to the
sole creates deflection of the footwear sole substantially equal to
the height of either the object or other irregularity or variation
in terrain. If the sole is unable to compress the required
distance, then the sole is forced into uneven contact with the
ground to compensate for the remaining distance. If the force is
applied either medially or laterally of the centerline of the foot,
the sole may be forced into an angle relative to the ground in the
medial-lateral direction, as shown in FIGS. 30a-c. This may cause
either excessive pronation (eversion) (FIG. 30b) or excessive
supination (inversion) (FIG. 30a) of the foot (as compared to a
neutral stance as shown in FIG. 30c), which may extend beyond a
desirable range for a stable stance phase.
[0061] The monolithic sole structure found in many traditional
articles of footwear that are designed for running or jogging is
not designed to deform by an appreciable amount in response to the
impact of ground reaction forces or point loading and, therefore,
can lead to instability when reacting thereto. The present
embodiment of this invention, which allows for the independent
deflection of the lugs 17, keeps the footwear wearer's ankle and
therefore the whole body in better alignment because it is better
able to maximize attenuation of reaction forces during foot strike
with the independent lug and plate configuration of the bottom
portion of the shoe. Ground reaction forces created by objects or
uneven terrain underfoot are independently absorbed by the lugs 17,
which minimizes or eliminates the transference of such forces to
the wearer's foot and, therefore, the lower body. This increases
stability, reduces risk of turning an ankle and reduces the
transference of instability through the sole 14 and up the body to
the knee, hip and upper body as compared to monolithic sole
structures. Therefore, reduction of the propagation of the effects
of uneven terrain keeps the foot in a more neutral position, keeps
the rear foot angle .theta. (FIG. 31) within a more acceptable
range and, therefore, increases stability throughout the entire the
body. There is also an increase in protection for the foot from
excessive penetration of portions of sole 14 on uneven surfaces or
point loading.
[0062] As shown in FIGS. 13a-d, lugs 17 allow for improved
absorption of forces applied to sole 14 due to objects 100
encountered during use of shoe 10 by reacting independently to the
application of such forces to prevent or reduce pronation or
supination of the foot in reaction to such forces. This independent
reaction to forces also helps promote better force distribution
throughout the sole 14 as compared to monolithic sole structures.
In particular, when one lug 17a contacts an object 100 which
extends above the adjacent ground surface 102, that lug 17a
compresses, while the remaining lugs 17b, 17c do not compress, or
compress at a lesser distance than lug 17a, and, preferably,
continue to make contact with the ground 102. This function of sole
14 is further illustrated in FIGS. 14a-b, where lug 17h reacts
independently to the force caused by object 100, while lugs 17g and
171 make substantial contact with ground 102. It is to be
understood, however, that the ability of the lugs 17 to maintain
contact with the ground when one or more of the lugs (17a in FIGS.
13a-d and 17h in FIGS. 14a-b, for example) encounter an object is
determined by the configuration of lugs 17. For example, the height
of the lugs 17 may limit such an ability when the object
encountered has a height that is greater than that of lugs 17. Such
"bottoming out" of lugs 17, may cause other lugs 17 to loose
contact with the ground. Nevertheless, the compression of lugs 17
may continue to provide for increased stability over typical
footwear structures because the distance of compression of the
individual lugs 17 reduces the rear foot angle .theta. (FIG. 31) as
compared to a typical monolithic sole structure when encountering
an object of the same size. Additionally, a single object may cause
multiple lugs 17 to compress at least partially, depending on, for
example, the size of the object. In this case, some or all of the
lugs 17 may contour to the ground surface by "giving" in response
to impact with the object, which maintains substantial contact with
the ground surface to further promote stability.
[0063] The design and structure of both support plate 20 and
midsole 14 allow lugs 17 to effectively attenuate forces and
increase stability of the shoe. Specifically, the generally
compliant midsole composition allows for compression of one or more
of lugs 17 depending on the nature, size, and/or shape of the
compression-inducing object 100, or other ground surface
irregularity, allowing lugs 17 to cushion the foot and contribute
to force attenuation. With respect to support plate 20, the more
rigid structure thereof provides stability for sole 14, allowing
sole 14 to resist torsional movement and flexing. Further, support
plate 20 gives additional support to the areas of sole 14 between
lugs 17, which prevents compression of one lug 17 from causing
deformation of the adjacent portions of sole 14. Still further, the
structure of cantilevered elements 24 of suspension plate 20 give
directional properties to lugs 17. For example, the cantilevered
elements 24 are preferably positioned to cover a single side of a
particular lug 17 and the ground contacting portion thereof. This
allows for such a lug 17 to deflect generally upwardly in a
compressive motion wherein cantilever element 24 rotates or pivots
about an axis lying along the portion of suspension plate 20 where
cantilevered element 24 meets body 25 of plate 20. In such an
arrangement, projection 30 compresses to accommodate and support
the rotation or pivoting of cantilevered element 24. Preferably
cantilever elements 24 of lugs 17 located on the forefoot section
of sole 14 extend on the anterior surface of projections 30, and
cantilever elements 24 of lugs 17 located on heel portion 28 of
sole 14 are positioned on the anterior surface of projections 30.
This arrangement for the directional orientation of lugs 17 creates
a spring effect which aids in propulsion, braking, and
stability.
[0064] Furthermore, as shown in FIG. 17, cantilevered elements
include two angles, namely angles .beta. and .phi.. The values for
angles .beta. and .phi. should be selected to provide appropriate
height and anterior-posterior width characteristics for lugs 17, as
well as to properly align the ground-contacting portions thereof.
Additionally, angles .beta. and .phi. should be selected so as to
appropriately contribute to the directional properties of lugs 17
discussed above. For example, while both angles may be about
90.degree., such an arrangement would tend to favor vertical
compression of lugs 17 as opposed to rotation of cantilevered
element 24, which is preferred. Thus, angle .beta. is desirably an
obtuse angle and angle .phi. is desirably an acute angle. In one
embodiment angle .beta. is at least about 110.degree.. In another
embodiment angle .beta. is no greater than about 150.degree..
Preferably, angle .beta. is about 135.degree., for instance between
about 125.degree. and 145.degree., more preferably between about
130.degree. and 140.degree.. In a further embodiment angle .phi. is
at least about 20.degree.. In an alternative embodiment angle .phi.
is no more than about 60.degree.. Preferably, angle .phi. is about
45.degree., for instance between about 35.degree. and 55.degree.,
more preferably between about 40.degree. and 50.degree.. In one
example, the angles are selected so that the bottom of the lug 17
is substantially parallel to the ground or other terrain during
normal use conditions. Of course, it should be understood that
these angles are merely exemplary and may vary above or below these
ranges. It is also possible for different lugs 17 to have different
angles .beta. and/or .phi., for instance depending upon the size,
shape, placement, and/or orientation of a given lug 17.
[0065] As discussed above, the structure of suspension plate 20 may
include openings 27 above the portions of suspension plate 20 where
cantilever elements 24 project downwardly from body portion 25. The
openings 27 provide additional force attenuation by allowing
absorption of force applied to lug 17 not only in projection 30,
but also in the adjacent area of support portion 22. Further, the
incorporation of opening 27 into the structure of suspension plate
20 allows lugs 17 to be designed such that cantilever element 24
can be forced upward through opening 27, for instance during
extreme impact conditions for increased stability and force
attenuation.
[0066] Sole 14 may be structured so as to provide lugs 17 having
varying hardness among the different areas of sole 14. For example,
lugs 17 located near the perimeter of sole 14 can have a greater
hardness than those located near the center of sole 14. Such an
arrangement provides stability around the perimeter of sole 14,
while providing increased compression toward the center of sole 14.
Also, different lugs may have cantilevered elements 24 with
different properties, for instance different materials, thickness,
orientation, spacing, depth, etc. Additionally, lugs 17 can be
formed of cantilever elements 24, without having mating projections
30 formed in midsole 16. Such a structure for lugs 17 can be used
alone or in combination with lugs 17 having cantilever elements 24
and mating projections 30 formed in midsole 16 to provide desired
stability and force attenuation characteristics in various areas of
sole 14. In an alternative embodiment of the present invention,
cantilever elements 24 can be formed of alternative materials such
as carbon fiber or spring steel, which can be attached to a main
body 25 for suspension plate 20 that is made of the materials
discussed above. Cantilever elements 24 made of such materials may
have a hardness adequate to form lug 17 from cantilever element 24
having no mating projection 30 formed in midsole 16 (as shown in
FIGS. 26-29), or having mating projections 30 of a composition
different than the mating projections 30 of other lugs 17.
[0067] The hardness of lugs 17 can also be made so as to correspond
to various weights of various wearers of the footwear. For example,
a greater weight of the wearer will cause greater ground forces to
be applied underfoot due to objects or uneven terrain. This can
lead to diminished effectiveness of lugs with respect to both
stability and blunt force attenuation and can increase the
likelihood of bottoming out of lugs 17 during use. Accordingly,
lugs 17 may be structured so as to have a hardness that is greater
in similar footwear designed to be worn by a more lightweight
wearer. This increased hardness can counteract the increased ground
forces caused by the weight of the wearer. Conversely, a wearer
with a lower weight can reduce ground forces underfoot to a point
where the ground forces are no longer adequate to cause operative
movement of the individual lugs 17. This condition may be remedied
by reducing the hardness of lugs 17, thereby reducing the amount of
ground force necessary to cause deflection of lugs 17. In one
embodiment, an article of footwear of the present invention can be
designed to provide a desired hardness for lugs 17 so as to
correspond with a predetermined weight range for the wearer
thereof. In this embodiment of the present invention, the hardness
of lugs 17 can be varied by using different materials for midsole
16 or for cantilever elements 24, as well as by varying the size
and/or shape of projections 30 or cantilevered elements 24. As
different wearers of a shoe of the same size may be of varying
weights, footwear according to the present invention may be
provided that differ in both hardness levels, as well as size, for
lugs 17 throughout ranges which would be reasonably understood by
one having skill in the art.
[0068] Additionally, the structure of lugs 17 improves ground
contact for sole 14 when the shoe makes contact unevenly with the
ground, particularly when cornering or cutting. As shown in FIG.
13d, when shoe 10 contacts the ground unevenly, such as at angle
.alpha. in FIG. 13d, some or all of the individual lugs 17 may
compress so that substantially all lugs 17 make contact with the
ground surface 102. This improves traction, which is particularly
useful in such situations, as well as even support for the foot,
reducing the angle formed between the foot and lower leg, which
reduces problematic over-pronation or over-supination of the foot
compared to traditional footwear, and thus reduces ligament stress
at the ankle and enhances stability for the whole body.
[0069] Sole 14 can include any number of lugs 17, but preferably
includes more than one lug 17. In one preferred example, sole 14
preferably includes fewer than twenty lugs 17 and more preferably
includes about fourteen lugs 17. In another preferred example, sole
14 includes two lugs 17 in the heel region thereof, which extend
toward the forefoot portion and are formed so as to extend from
heel portion 28. Similarly, the toe region of sole 14 preferably
includes three lugs 17 which extend from toe portion 26 in a
generally posterior direction. In this example, sole 14 preferably
includes nine independent lugs located in the forefoot region.
These lugs 17 are preferably arranged in three rows of three lugs
each. The lugs are preferably between 5 mm and 15 mm long in the
anterior-posterior direction and are preferably between 12 mm and
32 mm long in the medial-lateral direction. Lugs 17 may be evenly
distributed throughout the forefoot portion of sole 14 in both the
medial and lateral directions. In one example, lugs 17 have a
height of at least 2 mm. In another example, lugs 17 have a height
of no more than 10 mm. In a further example lugs 17 preferably have
a height of between 7 mm and 23 mm and, more preferably, about 15
mm. Lugs 17 may be oriented in a generally grid-like pattern, or
may be in a staggered or other arrangement relative to each other.
While the size, spacing, orientation and arrangement of the lugs 17
may vary depending upon the type of shoe, environmental conditions,
fashion, etc., it is desired that different lugs 17 be able to
function, e.g. operate in a cantilever manner independently from
one another. In a further preferred example, a single lug 17 having
multiple zones which act generally independently from one another
is included in heel 28 and toe 26 portions of sole 14. Such
generally independent movement can be provided by separating the
zones into distinct portions (as shown in FIG. 4). In one example
of such an arrangement, a particular lug 17 may have a first zone
which when subjected to force from an object will deflect to absorb
such force, and the lug may have a second zone which, by virtue of
being a part of the same lug, may deflect in response to the force,
but by somewhat less than the first zone.
[0070] Further arrangements for lugs 17 are contemplated, and can
include elongated outer toe lugs 19, as shown in FIGS. 3 and 4.
Additionally, lugs 17 can extend across the entire sole in the
medial-lateral direction, as shown in FIGS. 19-21. A further
variation of lugs 17 shown in FIG. 22 extends across sole in the
medial-lateral direction in a zig-zag or "V"-shape. Further,
various combinations of the aforementioned lug 17 shapes and
arrangements are possible. Such variations are designed to provide
the desired force attenuation and stability properties to various
areas of sole 14 as would be understood by one having reasonable
skill in the art upon reading this disclosure. Specifically,
multiple lug configurations can be used and can be combined with a
variety of traction elements in order to provide desirable traction
for a range of surfaces and conditions. For example, a heel of the
type typically found on athletic footwear can be used in
combination with lugs or spring elements located in the forefoot
region of the shoe.
[0071] Additionally, lugs 17 can vary in height within the design
of sole 14. Specifically, it may be desired to have specific lugs
17 that are shorter than adjacent lugs 17. For instance, some of
the lugs may have a height of about 15 mm and other lugs may have
heights between about 2 and 10 mm. As shown in FIG. 16, middle lug
17d can be shorter than outside lugs 17e, 17f In such an
arrangement, middle lug 17d may have a height that is between 0 and
10 mm less than the heights of outside lugs 17e, 17f. In such an
arrangement, outside lugs 17e, 17f contact the ground before middle
lug 17d. Such arrangements can be useful for cushioning or for
foot-strike control, such as pronation control. Additionally, lugs
17 may be shorter, for example in the toe region, as compared to
the forefoot region as this enables the shoe to provide a smoother
gait from heel strike to toe-off. Further, the structure of
cantilever element 24 is such that it prevents lugs 17 from bending
or flexing in the medial-lateral direction, which makes the shoe
more stable, particularly when cornering. Furthermore, additional
traction elements 40 (shown in FIGS. 6 and 7) preferably having a
height shorter than at least one of lugs 17 may be included in the
outsole 18 of the shoe. Such additional traction elements 40 may be
in the form of protrusions, including spikes. Such protrusions may
be resilient and be made from rubber or another suitable outsole
material, or may be rigid and be made from plastic, metal or other
such material. These additional traction elements 40 may be of a
sufficient height such that they engage the ground surface when
lugs 17 deflect in response to uneven terrain or the like.
[0072] As shown in FIG. 24, projections 30 can be formed with
hollow inside recesses 31 therein. Recesses 31 preferably extend
from the upper surface of support portion 22 and into at least a
portion of the interior of projection 30. This not only aids in
formation of projections 30, but can also be used to vary the
hardness or compressibility of lugs 17. For example, a larger
recess 31 will increase the compressibility of the corresponding
lug 17. Further, the shape of recesses 31 can vary within the
corresponding projection 31 in order to control the compression of
corresponding lugs 17. For example, recesses 31 of varying sizes
can be incorporated into lugs 17 to provide different levels of
compressibility from lugs formed from the same material. In an
example of such an embodiment, lugs 17 in or near the toe 26 or
heel 28 regions of sole 14 may be more or less compressible than
lugs in the remainder of sole 14. In one variation of this example,
lugs 17 in heel region 28 may be more compressible than the
remaining lugs 17, particularly those in the toe region 26. This
can be done in order to provide additional foot strike cushioning
for runners who make initial contact with the ground with their
heel. In another example of this embodiment, lugs 17 on the medial
side of sole 17 may be more or less compressible than lugs 17 on
the lateral side of sole 14. In one variation of this example, lugs
17 on the medial side of sole 14 are less compressible than lugs 17
on the lateral side of sole 14. This variation may be used, for
example, to control pronation of the foot during running. Further
variations of the foregoing examples are possible, and may include
various combinations thereof. As discussed above, it may be
desirable to vary the hardness of lugs 17 to accommodate for
varying weights of wearers of footwear. This variation can be
further accomplished by varying the size of the recess 31 within
lugs 17.
[0073] Referring now to FIG. 23 a process for making sole 14
according to an embodiment of the present invention is shown with
optional steps indicated by a broken line. In this process sole 14
according to an embodiment of the present invention is preferably
formed by providing a die-cut EVA foam blocker in step S110. The
general design and structure of blockers are generally known in the
art. The blocker is then compression molded in step S120 into the
desired shape, as discussed with reference to the various figures
herein. Outsole 18 is then compression molded in step S130 (which
can be completed contemporaneously with the compression molding of
midsole) from stock rubber. As discussed above, this can be done so
as to form individual sections of outsole 18, which correspond to
specific areas of sole 14 or so as to form an outsole 18 that
substantially covers the entire bottom surface of sole 14.
Suspension plate 20 is then co-molded with outsole 18 in step S150
(which can also be completed contemporaneously with the compression
molding of midsole). In such a co-molding process, outsole 18 is
inserted into appropriate cavities in a mold at step S140, and then
suspension plate 20 is formed within the mold by injection molding.
Once the combination suspension plate and outsole has cooled, it is
removed from the mold in step S160 and attached to midsole 16 using
an adhesive. Preferably, such an adhesive is heat-activated, and is
applied to suspension plate 20 and allowed to dry in step S170. The
adhesive is then heated so that it becomes activated in step S180.
Midsole 16 is then assembled with suspension plate 20 and then
placed in a press in step S200 to ensure proper adhesion of the
parts to form sole 14.
[0074] Alternative processes for forming sole 14 according to an
embodiment of the present invention include injection molding
midsole 16 with projections 30 formed therein. If midsole 16 is
formed by injection molding, it can nonetheless be compression
molded thereafter to add additional shape or features as would be
reasonably understood in the art. A further alternative includes
open pouring midsole 16 using PU. Both of the aforementioned
variations of midsole 16 may then be subjected to the remaining
process steps in order to form sole 14.
[0075] Alternatively, as illustrated in FIGS. 26-29, lugs 117, 217
may be formed by spring element 124, 224 affixed to suspension
plate 120, 220 and further having a portion of outsole 118, 218
affixed thereto. As shown in FIGS. 26 and 27, spring elements 124
may be formed separately from body 122 of suspension plate 120, and
may include attachment portion 123, and spring portion 125. In the
current embodiment, spring portion 125 projects away from
attachment portion 123. In this arrangement for lugs 117, spring
elements 124 may be formed from a material that is more rigid than
body 122. This is useful because it compensates for the support of
lug 117 which, in alternative embodiments of the present invention,
is provided by projections 17 (an example of which is shown in FIG.
1). Suitable materials for spring elements 124 include carbon fiber
composite and spring steel. Further, spring element 124 of the type
shown in FIGS. 26 and 27 could be integrally formed with body
122.
[0076] An alternative embodiment of a shoe 210 having lugs 217
formed from spring elements 224 is shown in FIGS. 28 and 29. In
this particular embodiment, spring element 224 is formed separately
from body 222 of plate 220 and includes attachment portion 223 and
spring portion 225. In this embodiment spring portion 225 extends
generally in the same direction as attachment portion 223. Further,
spring portion 225 may have a portion thereof which extends at
least partially under attachment portion 225. As with respect to
the embodiments discussed with reference to FIGS. 26 and 26, it may
be desirable to form spring elements 224 of a more rigid material
than body 222.
[0077] Although the invention herein has been described with
reference to particular embodiments, it is to be understood that
these embodiments are merely illustrative of the principles and
applications of the present invention. It is therefore to be
understood that numerous modifications may be made to the
illustrative embodiments and that other arrangements may be devised
without departing from the spirit and scope of the present
invention as defined by the appended claims.
* * * * *