U.S. patent application number 17/497380 was filed with the patent office on 2022-04-14 for systems and methods for adjusting friction.
The applicant listed for this patent is The Brigham and Women's Hospital, Inc., Massachusetts Institute of Technology, President and Fellows of Harvard College. Invention is credited to Ahmad Rafsanjani Abbasi, Sahab Babaee, Katia Bertoldi, Robert S. Langer, Simo Pajovic, Carlo Giovanni Traverso.
Application Number | 20220110410 17/497380 |
Document ID | / |
Family ID | |
Filed Date | 2022-04-14 |
United States Patent
Application |
20220110410 |
Kind Code |
A1 |
Langer; Robert S. ; et
al. |
April 14, 2022 |
SYSTEMS AND METHODS FOR ADJUSTING FRICTION
Abstract
A shoe comprises an upper portion, a sole, and a sheet of
material. The upper portion is configured to receive a foot of a
user. The sole is attached to the upper portion. The sheet of
material is coupled to the sole. The material includes a substrate
and one or more movable projections. The one or more movable
projections are configured to extend from the substrate. The one or
more movable projections are configured to move between a first
orientation and a second orientation relative to the substrate, in
response to the sole of the shoe moving between a generally flat
configuration and a generally flexed configuration. The movable
projections can have a triangular shape, a concave shape, a convex
shape, a rectangular shape, or a barbed shape; and can be arranged
in a one-direction pattern, a three-column pattern, a half pattern,
a 16x2 pattern, or a checkerboard pattern.
Inventors: |
Langer; Robert S.;
(Cambridge, MA) ; Bertoldi; Katia; (Cambridge,
MA) ; Traverso; Carlo Giovanni; (Boston, MA) ;
Babaee; Sahab; (Cambridge, MA) ; Abbasi; Ahmad
Rafsanjani; (Cambridge, MA) ; Pajovic; Simo;
(Cambridge, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
President and Fellows of Harvard College
The Brigham and Women's Hospital, Inc.
Massachusetts Institute of Technology |
Cambridge
Boston
Cambridge |
MA
MA
MA |
US
US
US |
|
|
Appl. No.: |
17/497380 |
Filed: |
October 8, 2021 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
63198325 |
Oct 11, 2020 |
|
|
|
International
Class: |
A43B 13/22 20060101
A43B013/22 |
Claims
1. A material for adjusting an amount of friction between the
material and an object, the material comprising: a substrate; and
one or more movable projections configured to extend from the
substrate, the one or more movable projections being configured to
move between a first orientation relative to the substrate and a
second orientation relative to the substrate, in response to
movement of the substrate.
2. The material of claim 1, wherein when the movable projections
are in in the first orientation, the movable projections are
coplanar with the substrate.
3. The material of claim 1, wherein when the movable projections
are in the second orientation, the movable projections extend from
the substrate at an angle relative to the substrate.
4. The material of claim 3, wherein the angle is greater than 0
degrees and less than or equal to 90 degrees.
5. The material of claim 1, wherein the substrate is movable
between a first configuration and a second configuration, the first
configuration having a first curvature and the second configuration
having a second curvature greater than the first curvature.
6. The material of claim 5, wherein when the substrate is in the
first configuration, the movable projections are in the first
orientation relative to the substrate.
7. The material of claim 5, wherein when the substrate is in the
second configuration, the movable projections are in the second
orientation relative to the substrate.
8. The material of claim 5, wherein the movable projections are
configured to move between the first orientation and the second
orientation in response to the substrate moving between the first
configuration and the second configuration.
9. The material of claim 5, wherein the first curvature is about
zero, such that the first configuration is a generally flat
configuration.
10. The material of claim 9, wherein the second configuration is
greater than zero, such that the second configuration is a
generally flexed configuration.
11. The material of claim 9, wherein when the substrate is in the
first configuration and the movable projections are in the first
orientation, the substrate and the movable projections form a
generally flat contact area between the material and the object,
the generally flat contact area having a first coefficient of
friction.
12. The material of claim 11, wherein when the substrate is in the
second configuration and the movable projections are in the second
orientation, the substrate and the movable projections form a
generally rough contact area between the material and the
objection, the generally rough contact area having a second
coefficient of friction that is greater than the first coefficient
of friction.
13. The material of claim 1, wherein the movable projections are
integrally formed with the substrate.
14. The material of claim 13, wherein the movable projections are
formed from a plurality of cuts in the substrate.
15. The material of claim 14, wherein the plurality of cuts in the
substrate are formed from a periodic array of cuts.
16. The material of claim 1, wherein the movable projections are
coupled to the substrate.
17. The material of claim 1, wherein the movable projections are
formed in a first side of the substrate, and wherein a second
opposing side of the substrate includes an adhesive material.
18. The material of claim 1, wherein the movable projections each
have a concave shape, a triangle shape, a convex shape, a
rectangular shape, a square shape, a barbed shape, or any
combination thereof.
19. The material of claim 1, wherein the movable projections are
arranged in a plurality of offset rows, the plurality of rows
including a first row, a second row positioned adjacent to the
first row, and a third row positioned adjacent to the second row,
such that the second row is positioned between the first row and
the third row.
20. The material of claim 19, wherein each movable projection in
the first row is aligned with a corresponding movable projection in
the third row, and wherein each movable projection in the second
row is not aligned with any corresponding movable projections in
the first row or the third row.
21. The material of claim 19, wherein when the movable projections
are in the second orientation relative to the substrate, all of the
movable projections extend away from the substrate and in an
identical direction along the substrate.
22. The material of claim 1, wherein the movable projections are
arranged in a plurality of groups along the substrate.
23. The material of claim 22, wherein the plurality of groups
includes a first group and a second group positioned adjacent to
the first group
24. The material of claim 23, wherein when the movable projections
in the first group are in the second orientation relative to the
substrate, each of the movable projections in the first group
extends away from the substrate and in a first direction along the
substrate.
25. The material of claim 24, wherein when the movable projections
in the second group are in the second orientation relative to the
substrate, each of the movable projections in the second group
extends away from the substrate and in a second direction along the
substrate, the second direction being opposite the first
direction.
26. The material of claim 23, wherein the plurality of groups
includes a third group positioned adjacent to the second group,
such that the second group is positioned between the first group
and the third group.
27. The material of claim 26, wherein when the movable projections
in the third group are in the second orientation relative to the
substrate, each of the movable projections in the third group
extends away from the substrate and in the first direction along
the substrate.
28. The material of claim 22, wherein the movable projections in
each group are arranged in a plurality of offset rows, the
plurality of rows including a first row, a second row positioned
adjacent to the first row, and a third row positioned adjacent to
the second row, such that the second row is positioned between the
first row and the third row.
29. The material of claim 28, wherein each movable projection in
the first row is aligned with a corresponding movable projection in
the third row, and wherein each movable projection in the second
row is not aligned with any corresponding movable projections in
the first row or the third row.
30. The material of claim 21, wherein when the movable projections
are in the second orientation relative to the substrate, each of
the plurality of groups of movable projections is separated from at
least one adjacent group of the plurality of group by a portion of
the substrate with no movable projections.
31. The material of claim 21, wherein when the movable projections
are in the second orientation relative to the substrate, each of
the plurality of groups of movable projections is positioned
directly next to at least one adjacent group of the plurality of
groups, such that there is no portion of the substrate lacking
movable projections that separates each of the plurality of groups
from the at least one adjacent group.
32. The material of claim 1, wherein the movable projections are
arranged in a plurality of offset rows, the plurality of rows
including a first row, a second row positioned adjacent to the
first row, and a third row positioned adjacent to the second row,
such that the second row is positioned between the first row and
the third row.
33. The material of claim 32, wherein when the movable projections
in the first row and the second row are in the second orientation
relative to the substrate, each of the movable projections in the
first row and the second row extends away from the substrate and in
a first direction along the substrate.
34. The material of claim 33, wherein when the movable projections
in the third row are in the second orientation relative to the
substrate, each of the movable projections in the third row extends
away from the substrate and in a second direction along the
substrate, the second direction being opposite the first
direction.
35. The material of claim 32, wherein each movable projection in
the first row is aligned with a corresponding movable projection in
the third row, and wherein each movable projection in the second
row is not aligned with any corresponding movable projection in the
first row or the third row.
36. The material of claim 32, wherein when the movable projections
are in the second orientation relative to the substrate, each of
the plurality of rows of movable projections is positioned directly
next to at least one adjacent row of the plurality of rows, such
that there is no portion of the substrate lacking movable
projections that separates each of the plurality of rows from the
at least one adjacent row.
37. The material of claim 1, wherein the movable projections are
arranged in a first group, a second group, a third group, and a
fourth group, the set of groups forming a generally square or
generally rectangular shape.
38. The material of claim 37, wherein the second group is
positioned adjacent to the first group along a first axis, wherein
the fourth group is positioned adjacent to the first group along a
second axis that is perpendicular to the first axis, and wherein
the third group is positioned diagonal from the first group along
both the first axis and the second axis.
39. The material of claim 38, wherein the movable projections in
the first group and the third group extend away from the substrate
and in a first direction along the substrate when in the second
orientation.
40. The material of claim 39, wherein the movable projections in
the second group and the fourth group extend away from the
substrate and in a second direction along the substrate when in the
second orientation, the second direction being opposite the first
direction.
41. The material of claim 40, wherein the first direction and the
second direction are opposing directions along the first axis.
42. The material of claim 37, wherein the movable projections in
each group are arranged in a plurality of offset rows, the
plurality of rows including a first row, a second row positioned
adjacent to the first row, and a third row positioned adjacent to
the second row, such that the second row is positioned between the
first row and the third row.
43. The material of claim 42, wherein each movable projection in
the first row is aligned with a corresponding movable projection in
the third row, and wherein each movable projection in the second
row is not aligned with any corresponding movable projections in
the first row or the third row.
44. The material of claim 37, wherein when the movable projections
are in the second orientation relative to the substrate, the first
group and the second group are separated from the third group and a
fourth group by a portion of the substrate with no movable
projections that extends along the first axis.
45. The material of claim 37, wherein the movable projections are
formed in a periodic array of movable projections, each period of
the array of movable projections including one of the first group
of movable projections, one of the second group of movable
projections, one of the third group of movable projections, and one
of the fourth group of movable projections.
46. The material of claim 1, wherein the substrate and the movable
projections are formed polyester plastic, spring steel,
polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE),
silicone-based rubber, a plastic, a metal, a polymer, a composite,
or any combination thereof.
47. The material of claim 1, wherein the substrate and each of the
movable projections has a thickness that is between about 0.002
inches and about 0.05 inches.
48. The material of claim 1, wherein the substrate is configured to
be coupled to a sole of a shoe worn by a user, and wherein when the
movable projections are in the second orientation relative to the
substrate, the movable projections are configured to extend away
from sole of the shoe toward a surface on which the user is
walking.
49. The material of claim 48, wherein the movable projections are
configured to move between the first orientation and the second
orientation as the user walks on the surface.
50. The material of claim 49, wherein the movable projections are
configured to move from the first orientation to the second
orientation in response to the shoe flexing as the user walks, and
wherein the movable projections are configured to return to the
first orientation from the second orientation when the shoe
flattens as the user walks.
51. The material of claim 1, wherein the object is a surface that
the material is configured to contact.
52. A shoe comprising: an upper portion configured to receive a
foot of a user; a sole attached to the upper portion; and a sheet
of material coupled to the sole, the material including: a
substrate; and one or more movable projections configured to extend
from the substrate, the one or more movable projections being
configured to move between a first orientation relative to the
substrate and a second orientation relative to the substrate, in
response to the sole of the shoe moving between a generally flat
configuration and a generally flexed configuration.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of, and priority to,
U.S. Provisional Patent Application No. 63/198,325 filed on Oct.
11, 2020, which is hereby incorporated by reference herein in its
entirety.
TECHNICAL FIELD
[0002] The present disclosure relates generally to systems and
devices for adjusting friction. More particularly, aspects of this
disclosure relate to a material for adjusting the amount of
friction between the material and an object.
BACKGROUND
[0003] Accidental slips and falls are a common health problem that
is ranked as the second-leading cause of occupational deaths, and
the leading cause of death for older adults. The direct costs of
fatal and non-fatal fall accidents and the related medical care is
estimated to be more than $64 billion per year in the United
States. In colder countries--such as Nordic countries where snow
and ice are generally present for at least half the year--the total
cost is higher, and is almost equal to the cost of all traffic
injuries. Musculoskeletal injuries due to slip and fall accidents,
such as osteoporotic fractures and hip fractures, are generally the
most-costly injuries, particularly among elderly people, where
one-third of people aged 65 or more fall at least once a year. In
addition, slip, trip and fall incidents associated with ice and
snow can be major causes of injuries and hospitalizations,
particularly for public and outdoor workers such as postal workers
and construction workers. These slip, trip, and fall incidents
result in around 65% of the lost workdays in the US, which is
estimated to cost more than $7 billion per year. Thus, new
techniques for adjusting the friction between a user's shoes and a
slippery surface are needed to prevent or minimize slipping and
falling.
SUMMARY
[0004] According to one aspect of the present disclosure, a
material is directed to adjusting an amount of friction between the
material, and an object includes a substrate and one or more
movable projections. The one or more movable projections are
configured to extend from the substrate. The one or more movable
projections are further configured to move between a first
orientation and a second orientation relative to the substrate, in
response to movement of the substrate.
[0005] According to another aspect of the present disclosure, a
shoe includes an upper portion, a sole, and a sheet of material.
The upper portion is configured to receive a foot of a user. The
sole is attached to the upper portion. The sheet of material is
coupled to the sole. The material includes a substrate and one or
more movable projections. The one or more movable projections are
configured to extend from the substrate. The one or more movable
projections are configured to move between a first orientation and
a second orientation relative to the substrate, in response to the
sole of the shoe moving between a generally flat configuration and
a generally flexed configuration.
[0006] The above summary is not intended to represent each
embodiment or every aspect of the present disclosure. Rather, the
foregoing summary merely provides an example of some of the novel
aspects and features set forth herein. The above features and
advantages, and other features and advantages of the present
disclosure, will be readily apparent from the following detailed
description of representative embodiments and modes for carrying
out the present invention, when taken in connection with the
accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The disclosure will be better understood from the following
description of exemplary embodiments together with reference to the
accompanying drawings.
[0008] FIG. 1A is a perspective view of a shoe contacting a surface
in a flat configuration, according to aspects of the present
disclosure;
[0009] FIG. 1B is a perspective view of a sheet of material on the
underside of the shoe of FIG. 1A when the sheet of material is in a
first orientation, according to aspects of the present
disclosure;
[0010] FIG. 2A is a perspective view of the shoe of FIG. 1A
contacting the surface in a flexed configuration, according to
aspects of the present disclosure;
[0011] FIG. 2B is a perspective view of the sheet of material on
the underside of the shoe of FIG. 2A when the sheet of material is
in a second orientation, according to aspects of the present
disclosure;
[0012] FIG. 3A shows the material of FIG. 1B and FIG. 2B with
movable projections having a triangular shape, according to aspects
of the present disclosure;
[0013] FIG. 3B shows the material of FIG. 1B and FIG. 2B with
movable projections having a concave shape, according to aspects of
the present disclosure;
[0014] FIG. 3C shows the material of FIG. 1B and FIG. 2B with
movable projections having a convex shape, according to aspects of
the present disclosure;
[0015] FIG. 3D shows the material of FIG. 1B and FIG. 2B with
movable projections having a rectangular shape, according to
aspects of the present disclosure;
[0016] FIG. 3E shows the material of FIG. 1B and FIG. 2B with
movable projections having a barbed shape, according to aspects of
the present disclosure;
[0017] FIG. 4A shows the movable projections of FIG. 3C arranged in
a one-direction pattern, according to aspects of the present
disclosure;
[0018] FIG. 4B shows the movable projections of FIG. 3C arranged in
a three-column pattern, according to aspects of the present
disclosure;
[0019] FIG. 4C shows the movable projections of FIG. 3C arranged in
a half pattern, according to aspects of the present disclosure;
[0020] FIG. 4D shows the movable projections of FIG. 3C arranged in
a 16.times.2 pattern, according to aspects of the present
disclosure;
[0021] FIG. 4E shows the movable projections of FIG. 3C arranged in
a checkerboard pattern, according to aspects of the present
disclosure;
[0022] FIG. 5 is a plot measuring imparted force versus
displacement for the sheet of material of FIG. 1B and FIG. 2B,
according to aspects of the present disclosure;
[0023] FIG. 6 is a plot comparing the static and kinetic
coefficients of friction for sheets of material having movable
projections arranged in the patterns of FIGS. 4A-4E, according to
aspects of the present disclosure; and
[0024] FIG. 7 is a plot comparing the static and kinetic
coefficients of friction for sheets of material having movable
projections with the shapes of FIGS. 3A-3E, according to aspects of
the present disclosure.
[0025] The present disclosure is susceptible to various
modifications and alternative forms. Some representative
embodiments have been shown by way of example in the drawings and
will be described in detail herein. It should be understood,
however, that the invention is not intended to be limited to the
particular forms disclosed. Rather, the disclosure is to cover all
modifications, equivalents, and alternatives falling within the
spirit and scope of the invention as defined by the appended
claims.
DETAILED DESCRIPTION
[0026] The present inventions can be embodied in many different
forms. Representative embodiments are shown in the drawings, and
will herein be described in detail. The present disclosure is an
example or illustration of the principles of the present
disclosure, and is not intended to limit the broad aspects of the
disclosure to the embodiments illustrated. To that extent,
elements, and limitations that are disclosed, for example, in the
Abstract, Summary, and Detailed Description sections, but not
explicitly set forth in the claims, should not be incorporated into
the claims, singly or collectively, by implication, inference, or
otherwise. For purposes of the present detailed description, unless
specifically disclaimed, the singular includes the plural and vice
versa; and the word "including" means "including without
limitation." Moreover, words of approximation, such as "about,"
"almost," "substantially," "approximately," and the like, can be
used herein to mean "at," "near," or "nearly at," or "within 3-5%
of," or "within acceptable manufacturing tolerances," or any
logical combination thereof, for example.
[0027] FIG. 1A shows a shoe 12 standing on a surface 10 in a flat
configuration. The surface 10 can be a floor, the ground, or any
other surface that a person wearing a shoe may be standing on. The
shoe 12 has an upper portion 13 and a sole 14 attached to the upper
portion 13. The upper portion 13 is configured to receive a foot of
a user wearing the shoe. In FIG. 1A, the shoe 12 is in a flat
configuration on the surface 10. FIG. 1B shows a material 100
coupled to the sole 14 that can be used to adjust the amount of
friction between the shoe 12 and the surface 10. The material 100
is formed from a substrate 102 and a plurality of movable
projections 104. In the illustrated implementation, the substrate
102 includes a number of cuts or apertures. The material leftover
forms the movable projections 104. Thus, the movable projections
are integrally formed with the substrate 102. However, in other
implementations, the movable projections 104 can be separate
components that are coupled to the substrate 102. In some
implementations, the movable projections 104 are formed on a first
side of the substrate 102, and an opposing second side of the
substrate 102 includes an adhesive material that can be used to
adhere the material 100 to the sole 14 of the shoe 12. The adhesive
material can be covered by a temporary layer. Thus, attaching the
substrate 102 to the sole 14 of the user's shoe 12 can be achieved
by removing the temporary layer to reveal the adhesive material,
and then pressing the side of the substrate 102 with the adhesive
material to the sole 14. In some implementations, the substrate 102
can be shaped to fit the sole 14 (for example, by cutting the
desired shape out of a larger piece of material) before or after
attaching the substrate 102 to the sole 14.
[0028] FIG. 1A shows the shoe 12 in a generally flat configuration
with little to no curvature. As shown in FIG. 1B, because the
material 100 can be attached to the sole 14 of the shoe 12, the
substrate 102 also has a generally flat configuration with little
to no curvature. When the substrate 102 is in the generally flat
configuration, the movable projections 104 are in a first
orientation relative to the substrate 102. In the first
orientation, the movable projections 104 are generally coplanar
with the substrate 102. As can be seen in the zoomed-in inset view
of FIG. 1B, the movable projections 104 can occupy a substantial
portion of the surface area of the material 100, such that the
substrate 102 exists only in the small areas of the material 100
between the movable projections 104.
[0029] When the substrate 102 is in the flat configuration and the
movable projections 104 are in their first orientation where they
are coplanar with the substrate 102, the substrate 102 and the
movable projections 104 form a generally flat contact area between
the surface 10 and the material 100. This flat contact area
provides a certain coefficient of friction between the surface 10
and the shoe 12/the material 100.
[0030] FIG. 2A shows the shoe 12 in a flexed and/or stretched
configuration during the user's stride. Specifically, FIG. 2A
illustrates the position of the shoe 12 during the portion of the
user's stride when the user is pushing forward (e.g., to the right
relative to the plane of FIG. 2A) off of the shoe 12, and thus
exerting a backwards force (e.g., a force directed to the left
relative to the plane of FIG. 2A) on the shoe 12. FIG. 2B shows the
substrate 102 of the material 100 in the flexed and/or stretched
configuration. In their flexed configurations, the shoe 12 and the
substrate 102 have a larger curvature than in their generally flat
configurations. Because the material 100 is coupled to the sole 14
of the shoe 12, the substrate 102 moves to its flexed configuration
as the shoe 12 moves to its flexed configuration as the user
wearing the shoe 12 walks on the surface 10. When the substrate 102
moves to the flexed configuration, the movable projections 104 move
from their first orientation relative to the substrate 102 (FIG.
1B) to a second orientation relative to the substrate 102.
[0031] The zoomed-in inset view of FIG. 2A shows that the movable
projections 104 are formed from a plurality of cuts or openings
defined in the substrate 102. Because of these cuts, as the
substrate 102 flexes and moves to the second configuration, the
movable projections 104 form a series of spikes that pop out of or
buckle up from the substrate 102 to the second orientation, with
gaps 103 separating adjacent ones of the movable projections 104.
Thus, in the illustrated implementations, the material 100 can be
initially formed as a single sheet that forms the substrate 102,
with no cuts or openings defined in the sheet. Then, the cuts or
openings can be formed in the sheet of material 100. The portions
of the sheet of material 100 that pop out or buckle up will form
the movable projections 104, while the remaining portions of the
sheet of material 100 that do not pop out or buckle up will form
the substrate 102.
[0032] As can be seen in the zoomed-in inset views of both FIG. 2A
and FIG. 2B, when the movable projections 104 are in the second
orientation, the movable projections 104 extend from the substrate
102 at an angle relative to the substrate 102. Generally, this
angle can be any angle that is greater than about degrees and less
than or equal to about 90 degrees. Thus, when in the second
orientation, the movable projections 104 extend both away from the
substrate 102 (e.g., normal to the substrate 102), and in a
direction along the substrate 102 itself (e.g., along the sole 14
of the shoe 12). As can be seen in the zoomed-in inset view of FIG.
2B, the movable projections 104 are shown extending leftward
relative to the plane of FIG. 2B, which is backwards along the sole
14 toward the heel of the shoe 12. However, in other
implementations, the movable projections 104 can extend in
different directions or combinations of directions along the
substrate 102 (e.g., different directions along the sole 14 of the
shoe 12).
[0033] When the substrate 102 is in the flexed configuration and
the movable projections 104 have moved to their second orientation
where they extend away from the substrate 102, the substrate 102
and the movable projections 104 form a generally rough contact area
between the surface 10 and the material 100. This rough contact
area provides a coefficient of friction between the surface 10 and
the shoe 12/the material 100 that is greater than the coefficient
present when the movable projections 104 are in their first
orientation.
[0034] Thus, as the user walks in the shoes 12 with the material
100 adhered on the soles 14, the movable projections 104 move
between the first orientation (coplanar with the substrate 102) and
the second orientation (extending away from the substrate 102). As
shown in FIG. 2B, when the movable projections 104 are in the
second orientation, the movable projections 104 can dig in to the
surface 10, thereby increasing the coefficient of friction between
the surface 10 and the shoe 12/the material 100. When the user
pushes off of the shoe 12 and exerts a backward force on the shoe
12, the movable projections 104 being in the second orientation
(e.g., extending both away from the sole 14 and generally backwards
along the sole 14) increases the amount of friction between the
user's shoes 12 and the surface 10 to be increased, which in turn
decreases the chance that the user will slip, trip, fall, etc. The
material 100 can be used on a variety of different surfaces, such
as hardwood floor, vinyl, concrete, asphalt, gravel, oily or wet
surfaces, etc. Because the movable projections 104 are configured
to move to the second orientation as the user is walking and the
user's shoe 12 moves to the flex configuration, no additional
energy source is needed to increase the friction between the user's
shoe 12 and the object or surface on which the user is walking.
[0035] Referring now to FIGS. 3A-3E, the movable projections 104
can be formed in a variety of different shapes. FIG. 3A includes
boxes 302A, 304A, and 306A that show the material 100 when the
movable projections 104 have a triangular shape. The upper box 302A
shows an outline of the cut in the material 100 that forms each of
the movable projections 104. As shown, the cut has a triangular
shape that includes two generally straight edges meeting at a
point. The upper box 302A thus shows the triangular leading edge of
each of the movable projections 104. The middle box 304A shows the
material 100 when the substrate is in the generally flat
configuration, for example when the material 100 is adhered to the
user's shoe and the shoe is flat on the ground while the user
walks. In the generally flat configuration, while the triangular
outline of the cut that forms movable projections 104 is visible,
the movable projections 104 do not extend from the substrate, and
thus the material 100 forms a generally flat contact surface. The
lower box 306A shows the material 100 when the substrate is in the
generally flexed configuration, for example when the material 100
is adhered to the user's shoe and the shoe is flexed while the user
walks. In the generally flexed configuration, the triangular
movable projections 104 begin to fold in half and extend away from
the substrate, thereby increasing the coefficient of friction
between the shoe and the ground, and thus the amount of friction
between the shoe and the ground.
[0036] FIG. 3B includes boxes 302B, 304B, and 306B that show the
material 100 when the movable projections 104 have a concave shape.
The upper box 302B shows an outline of the cut in the material 100
that forms each of the movable projections 104. As shown, the cut
has a generally concave shape. The concave shape is similar to the
triangular shape in box 302A, and includes two edges meeting at a
point. However, the edges are not straight, but instead curve
upward and outward (with respect to the plane of FIG. 3), such that
the shape has a degree of concavity. The upper box 302B thus shows
the concave-shaped leading edge of each of the movable projections
104. The middle box 304B shows the material 100 when the substrate
is in the generally flat configuration, for example when the
material 100 is adhered to the user's shoe and the shoe is flat on
the ground while the user walks. In the generally flat
configuration, while the concave outline of the cut that forms
movable projections 104 is visible, the movable projections 104 do
not extend from the substrate, and thus the material 100 forms a
generally flat contact surface. The lower box 306B shows the
material 100 when the substrate is in the generally flexed
configuration, for example when the material 100 is adhered to the
user's shoe and the shoe is flexed while the user walks. In the
generally flexed configuration, the concave-shaped movable
projections 104 begin to fold in half and extend away from the
substrate, thereby increasing the coefficient of friction between
the shoe and the ground, and thus the amount of friction between
the shoe and the ground.
[0037] FIG. 3C includes boxes 302C, 304C, and 306C that show the
material 100 when the movable projections 104 have a convex shape.
The upper box 302C shows an outline of the cut in the material 100
that forms each of the movable projections 104. As shown, the
convex shape is a generally half-circle shape. The upper box 302C
thus shows the convex-shaped leading edge of each of the movable
projections 104. The middle box 304C shows the material 100 when
the substrate is in the generally flat configuration, for example
when the material 100 is adhered to the user's shoe and the shoe is
flat on the ground while the user walks. In the generally flat
configuration, while the concave outline of the cut that forms
movable projections 104 is visible, the movable projections 104 do
not extend from the substrate, and thus the material 100 forms a
generally flat contact surface. The lower box 306C shows the
material 100 when the substrate is in the generally flexed
configuration, for example when the material 100 is adhered to the
user's shoe and the shoe is flexed while the user walks. In the
generally flexed configuration, the convex-shaped movable
projections 104 begin to fold in half and extend away from the
substrate, thereby increasing the coefficient of friction between
the shoe and the ground, and thus the amount of friction between
the shoe and the ground.
[0038] FIG. 3D includes boxes 302D, 304D, and 306D that show the
material 100 when the movable projections 104 have a rectangular
shape. The upper box 302D shows an outline of the cut in the
material 100 that forms each of the movable projections 104. As
shown, the rectangular shape is formed by a front edge and two side
edges extending generally perpendicularly from the front edge. The
upper box 302D thus shows the rectangular leading edge of each of
the movable projections 104. The middle box 304D shows the material
100 when the substrate is in the generally flat configuration, for
example when the material 100 is adhered to the user's shoe and the
shoe is flat on the ground while the user walks. In the generally
flat configuration, while the rectangular outline of the cut that
forms movable projections 104 is visible, the movable projections
104 do not extend from the substrate, and thus the material 100
forms a generally flat contact surface. The lower box 306D shows
the material 100 when the substrate is in the generally flexed
configuration, for example when the material 100 is adhered to the
user's shoe and the shoe is flexed while the user walks. In the
generally flexed configuration, the rectangular movable projections
104 begin to fold in half and extend away from the substrate,
thereby increasing the coefficient of friction between the shoe and
the ground, and thus the amount of friction between the shoe and
the ground.
[0039] FIG. 3E includes boxes 302E, 304E, and 306E that show the
material 100 when the movable projections 104 have a barbed shape.
The upper box 302E shows an outline of the cut in the material 100
that forms each of the movable projections 104. As shown, the
barbed shape is similar to the triangle shape or the concave shape,
and includes two edges that meet at a point. However, the two edges
include a plurality of barbs or points, such that the movable
projections 104 appear to have a wavy shape. The upper box 302E
thus shows the barb-shaped leading edge of each of the movable
projections 104. The middle box 304E shows the material 100 when
the substrate is in the generally flat configuration, for example
when the material 100 is adhered to the user's shoe and the shoe is
flat on the ground while the user walks. In the generally flat
configuration, while the barb-shaped outline of the cut that forms
movable projections 104 is visible, the movable projections 104 do
not extend from the substrate, and thus the material 100 forms a
generally flat contact surface. The lower box 306E shows the
material 100 when the substrate is in the generally flexed
configuration, for example when the material 100 is adhered to the
user's shoe and the shoe is flexed while the user walks. In the
generally flexed configuration, the barb-shaped movable projections
104 begin to fold in half and extend away from the substrate,
thereby increasing the coefficient of friction between the shoe and
the ground, and thus the amount of friction between the shoe and
the ground.
[0040] Referring now to FIGS. 4A-4E, the movable projections 104
can also be formed in a variety of different patterns. In some
implementations, the movable projections 104 are formed from a
periodic array of cuts. Each period of the array can include a
certain pattern of cuts that is repeated across all of the material
100. In some implementations, the periodic array might include
multiple levels of periodicity. For example, a smaller pattern of
cuts may be repeated across a subset of the material 100, and this
smaller pattern may be part of a larger pattern that is repeated
across all of the material 100.
[0041] FIG. 4A includes boxes 402A and 404A that illustrate the
movable projections 104 being arranged in a pattern referred to as
"1Dir" or "one direction." Box 402A shows the movable projections
104 when the material 100 is in the generally flat configuration,
and box 404A shows the movable projections 104 when the material
100 is in the generally flexed configuration. As can be seen, the
movable projections 104 are arranged into a plurality of offset
rows. The rows are offset from each other, such that a movable
projection 104 in any one row is not directly aligned with any of
the movable projections 104 in both the row above, or the row
below. For explanatory purposes, a first row 106A, a second row
106B, and a third row 106C are identified in box 404A. The second
row 106B is positioned between the first row 106A and the third row
106C. As can be seen, each movable projection 104 in the first row
106A is aligned with a corresponding movable projection 104 in the
third row 106C. However, none of the movable projections 104 in the
second row 106B are aligned with any corresponding movable
projections 104 in either the first row 106A or the third row 106C.
Instead, each movable projection 104 in the second row is aligned
with the movable projections 104 in a fourth row 106D that is
positioned immediately next to the third row 106C.
[0042] In some implementations, each row includes a single line of
movable projections 104 that all extend in an identical direction
along the substrate, when the movable projections 104 are in the
second orientation. For example, box 404A shows all of the movable
projections 104 extending away from the substrate and downward
relative to the plane of FIG. 4A. However, in other
implementations, different movable projections 104 within the same
row could extend in different directions. In further
implementations, the movable projections 104 within the same row
all extend in the same direction relative to the substrate, but
different rows of movable projections 104 could extend in different
directions. And in still further implementations, each row of
movable projections 104 could include multiple lines of movable
projections 104. In these implementations, each row of movable
projections 104 could include smaller sub-rows of movable
projections 104 that are aligned with each other. Moreover, the
rows of movable projections 104 can themselves extend in any
direction relative to the object that the material 100 is adhered
to. For example, when the material 100 is adhered to the sole of a
shoe, the rows of movable projections 104 could extend along the
length of the sole between the heel and the toe; along the width of
the sole between the inner portion of the sole and the outer
portion of the sole; or generally diagonally along both the length
and the width of the sole.
[0043] Referring now to FIG. 4B, the pattern of offset rows
illustrated in FIG. 4B can be part of a larger pattern of movable
projections 104. FIG. 4B includes boxes 402B and 404B that
illustrate the movable projections 104 being arranged in a pattern
referred to as "3Col" or "three column." Box 402B shows the movable
projections 104 when the material 100 is in the generally flat
configuration, and box 404B shows the movable projections 104 when
the material 100 is in the generally flexed configuration. In the
3Col arrangement, the movable projections 104 are arranged in three
different groups 108A, 108B, and 108C. In the illustrated
implementation, the groups 108A, 108B, and 108C extend along the
surface of the material 100 and are generally parallel to each
other. In that manner, the groups 108A, 108B, and 108C form three
columns that are vertical relative to the plane of FIG. 4B. The
movable projections 104 within each of the three groups 108A, 108B,
and 108C are arranged in 1Dir pattern shown in FIG. 4A, where one
row of movable projections 104 is offset from the rows of movable
projections 104 immediately adjacent to the one row on either side.
However, the movable projections 104 within each group 108A, 108B,
108C could be arranged in other patterns as well.
[0044] The movable projections 104 in the first group 108A and the
third group 108C all extend or point in the same direction (shown
as upward relative to the plane of FIG. 4B), while the movable
projections 104 in the second group 108B extend opposite from the
first group 108A and the third group 108C (shown as downward
relative to the plane of FIG. 4B). However, in other
implementations, the movable projections 104 in all three groups
108A, 108B, 108C could extend in the same direction, different
directions (e.g. upward, downward, and sideways relative to the
plane of FIG. 4B), or any combination of directions. If the
material 100 is adhered to the sole of a shoe, the groups 108A,
108B, and 108C could extend along the length of the sole of the
shoe, the width of the sole of the shoe, or generally along both
the length and the width of the sole of the shoe. Moreover, in this
implementation, the movable projections 104 could be arranged into
only two separate groups of movable projections, or four or more
groups of movable projections.
[0045] As can be seen by comparing box 404A and 404B, the cuts in
the material 100 that form the movable projections 104 are such
that when the movable projections 104 extend from the substrate in
the second orientation, gaps 110A and 110B are formed between each
of the groups 108A, 108B, 108C. In some implementations, the gaps
110A, 110B may be formed by portions of the substrate that have no
movable projections. In other implementations, the gaps may be
formed by portions of the object to which the material 100 is
adhered (e.g., a shoe sole).
[0046] Moreover, similar to the pattern in FIG. 4A, the rows of
movable projections 104 can themselves extend in any direction
relative to the object that the material 100 is adhered to. For
example, when the material 100 is adhered to the sole of a shoe,
the groups 108A, 108B, and 108C of movable projections 104 could
extend along the length of the sole between the heel and the toe;
along the width of the sole between the inner portion of the sole
and the outer portion of the sole; or generally diagonally along
both the length and the width of the sole.
[0047] It is further noted that FIG. 4B shows the movable
projections 104 extending generally along the same axis on which
the groups 108A, 108B, and 108C extend (e.g., the movable
projections 104 extend either upward or downward relative to the
plane of FIG. 4B when in the second orientation, and the groups
108A, 108B, and 108C also extend upward and downward relative to
the plane of FIG. 4B). However, in other implementations, the
movable projections 104 could extend in a different direction when
in the second orientation, as compared to the direction along which
the groups 108A, 108B, and 108C extend.
[0048] Referring now to FIG. 4C, boxes 402C and 404C illustrate the
movable projections 104 arranged in a pattern referred to as
"Half." Box 402C shows the movable projections 104 when the
material 100 is in the generally flat configuration, and box 404C
shows the movable projections 104 when the material 100 is in the
generally flexed configuration. In this pattern, the movable
projections 104 are arranged into two separate groups 112A and
112B. Similar to the 3Col pattern, the movable projections 104
within each group 112A, 112B are arranged using the offset row
arrangement of the 1Dir pattern. The movable projections 104 in
group 112A all extend or point upward relative to the plane of FIG.
4C, while the movable projections in group 112B all extend or point
downward relative to the plane of FIG. 4C. In other implementations
however, the movable projections 104 in groups 112A and 112B could
extend in the same direction, or even in directions perpendicular
to each other.
[0049] In the "Half" arrangement, the cuts in the material 100 that
form the movable projections 104 are such that when the movable
projections 104 extend from the substrate in the second
orientation, there are generally no gaps formed between the two
groups 112A and 112B, whether the gaps are formed from portions of
the substrate with no movable projections 104, or from portions of
the sole of the shoe. Instead, the row at the end of group 112A
(the bottom relative to the plane of FIG. 4C) and the row at the
end of group 112B (the top relative to the plane of FIG. 4C)
together form a single row that includes a plurality of pairs of
movable projections 104. Each pair of movable projections 104
includes a first movable projection that extends in the same
direction as the rest of group 112A when in the second orientation,
and a second movable projection that extends in the same direction
as the rest of group 112B when in the second orientation.
[0050] Similar to the patterns in FIGS. 4A-4B, the groups 112A,
112B of movable projections 104 can extend in any direction
relative to the objection that the material 100 is adhered to. For
example, when the material 100 is adhered to the sole of a shoe,
the groups 110A, 110B of movable projections 104 could extend along
the length of the sole between the heel and the toe; along the
width of the sole between the inner portion of the sole and the
outer portion of the sole; or generally diagonally along both the
length and the width of the sole. Moreover, the individual offset
rows of movable projections 104 can also extend in any direction
relative to the object that the material 100 is adhered to, e.g.,
along the length of the sole, along the width of the sole, or along
both the length of the sole and the width of the sole.
[0051] Referring now to FIG. 4D, boxes 402D and 404D illustrate the
movable projections 104 arranged in a pattern referred to as
"16.times.2." Box 402D shows the movable projections 104 when the
material 100 is in the generally flat configuration, and box 404D
shows the movable projections 104 when the material 100 is in the
generally flexed configuration. In this arrangement, the movable
projections 104 are arranged in a plurality of offset rows, similar
to the 1Dir pattern in FIG. 4A. However, instead of every row of
movable projections 104 extending or pointing in the same direction
along the substrate when the movable projections 104 are in the
second orientation, this pattern alternates the direction in which
the movable projections 104 extend or point every two rows. Thus,
for a first row 114A of movable projections 104, the movable
projections 104 in a second adjacent row 114B will extend in the
same direction as the movable projections 104 in the first row
114A, while the movable projections 104 in a third row 114C that is
adjacent to the second row 114B (e.g., the second row 114B is
disposed between the first row 114A and the third row 114C) will
extend in the opposite direction from the movable projections 104
in the first row 114A. This pattern of movable projections 104
maintains the offset row arrangement however. Thus, the movable
projections 104 in the second row 114B (e.g., the middle row) will
not be aligned with any corresponding movable projections 104 in
the first row 114A or the third row 114C, while each movable
projection 104 in the first row 114A will be aligned with a
corresponding movable projection 104 in the third row 114C, even
though the movable projections 104 will be extending in opposite
directions.
[0052] Similar to the patterns in FIGS. 4A-4C, the individual rows
of movable projections 104 can extend in any direction relative to
the objection that the material 100 is adhered to. For example,
when the material 100 is adhered to the sole of a shoe, the groups
110A, 110B of movable projections 104 could extend along the length
of the sole between the heel and the toe; along the width of the
sole between the inner portion of the sole and the outer portion of
the sole; or generally diagonally along both the length and the
width of the sole.
[0053] Referring now to FIG. 4E, boxes 402E and 404E illustrate the
movable projections 104 arranged in a pattern referred to as
"Checker" or "Checkerboard." Box 402E shows the movable projections
104 when the material 100 is in the generally flat configuration,
and box 404E shows the movable projections 104 when the material
100 is in the generally flexed configuration. In this pattern, the
movable projections 104 are generally arranged into four groups: a
first group 116A (upper-left relative to the plane of FIG. 4E), a
second group 116B (lower-left relative to the plane of FIG. 4E), a
third group 116C (lower-right relative to the plane of FIG. 4E),
and a fourth group 116D (upper-right relative to the plane of FIG.
4E). As can be seen in FIG. 4E, these four groups 116A-116D of
movable projections are arranged in a generally square or generally
rectangular shape.
[0054] The second group 116B is positioned adjacent to and spaced
apart from the first group 116A along a first axis 118A that
extends vertically relative to the plane of FIG. 4E. Similarly, the
third group 116C is positioned adjacent to and spaced apart from
the fourth group 116D along the first axis 118A. The fourth group
116D is positioned adjacent to and spaced apart from the first
group 116A along a second axis 118B that extends horizontally
relative to the plane of FIG. 4E. Similarly, the third group 116C
is positioned adjacent to and spaced apart from the second group
116B along the second axis 118B. Thus, the four groups 116A-116D
generally form the four quadrants of a square or rectangle.
[0055] When the movable projections 104 of the first group 116A are
in the second orientation, they extend along the substrate in a
first direction along the first axis 118A. Relative to the plane of
FIG. 4E, the first direction is downward. When the movable
projections 104 of the second group 116B are in the second
orientation, they extend along the substrate in a second direction
along the first axis 118A. Relative to the plane of FIG. 4E, the
second direction is upward. When the movable projections 104 of the
third group 116C are in the second orientation, they extend along
the substrate in the first direction along the first axis 118A.
When the movable projections 104 of the fourth group 116D are in
the second orientation, they extend along the substrate in the
second direction along the first axis 118A. Moreover, within each
group 116A-116D, the movable projections 104 are arranged in the
offset row pattern that is also illustrated in FIGS. 4A-4D.
[0056] As can be seen by comparing box 404E and 404E, the cuts in
the material 100 that form the movable projections 104 are such
that when the movable projections 104 extend from the substrate in
the second orientation, a gap 120 is formed that separates the
first group 116A and the second group 116B from the third group
116C and the fourth group 116D. In some implementations, the gap
120 may be formed from a portion of the substrate that has no
movable projections. In other implementations, the gap 120 may be
formed by portions of the object to which the material 100 is
adhered (e.g., a shoe sole). In some implementations, all of the
material 100 includes only the four groups 116A-116D. Thus, the
entire surface area of the material 100 can comprise only the four
groups 116A-116D. However, in other implementations, the four
groups 116A-116D of movable projections 104 are part of a larger
periodic array of movable projections 104, where each period
includes one of the first group 116A, one of the second group 116B,
one of the third group 116C, and one of the fourth group 116D.
[0057] The material 100 can be formed using a variety of different
materials and techniques. In some implementations, the material 100
is formed from polyester plastic and fabricated using laser cutting
techniques. In some of these implementations using polyester
plastic, the polyester plastic material has a thickness of about
0.005 inches and a tensile strength of about 30,000 pounds per
square inch (PSI). In further implementations, the material 100 is
formed from spring steel (such as blue tempered AISI 1095) and
fabricated using laser cutting techniques. In some of these
implementations using spring streel, the spring steel material has
a thickness of about 0.002 inches, a Rockwell hardness of C50, and
a tensile strength of about 238,000 PSI. In additional
implementations, the material 100 is formed from a polyester film,
such as a film formed from polyethylene terephthalate (PET), and
fabricated using laser cutting techniques. In some of these
implementations using PET, the polyester film has a thickness of
about 0.007 inches, and a tensile strength of about 28,000 PSI. In
other implementations, the material 100 is formed from
polytetrafluoroethylene (PTFE, also referred to as Teflon.RTM.) and
fabricated using laser cutting techniques. In some of these
implementations using PTFE, the PTFE material has a thickness of
about 0.01 inches, a Rockwell hardness of R60, and a tensile
strength of about 4,500 PSI.
[0058] In further implementations, the material 100 is formed from
a silicone-based rubber having a Shore A hardness value of 8, and
fabricated using casting techniques. In some of these
implementations, the silicone-based rubber material has a thickness
of about 0.05 inches and a tensile strength of about 300 PSI. In
additional implementations, the material 100 is formed from a
silicone-based rubber having a Shore A hardness value of 22, and
fabricated using casting techniques. In some of these
implementations, the silicone-based rubber material has a thickness
of about 0.05 inches and a tensile strength of about 400 PSI. In
other implementations, the material 100 is formed from a
silicone-based rubber having a Shore A hardness value of 32, and
fabricated using casting techniques. In some of these
implementations, the silicone-based rubber material has a thickness
of about 0.05 inches and a tensile strength of about 400 PSI. Thus,
the material 100 can have a thickness of between about 0.002 inches
and about 0.05 inches.
[0059] FIG. 5 shows a plot 500 that measures imparted force versus
the displacement of a testing sled containing a sheet of the
material 100. The sheet of the material 100 can be stretched across
the testing sled such that the movable projections move to their
second orientation. The testing sled can be placed onto a surface
such that the material 100 contacts the surface. A known mass (such
as a 5 kg mass) can be placed on top of the testing sled, and the
testing sled can be pulled at a constant velocity (such as 10
millimeters per second). The force imparted on the testing sled is
then measured as a function of the displacement of the testing sled
(e.g., the distance traveled), with the outcome being shown as plot
600.
[0060] Plot 500 thus illustrates the friction response of a sheet
of the material 100 on a surface. Force line 502 on plot 500
illustrates the static friction force, which is the amount of
imparted force required to overcome the static friction between the
sheet of material 100 and the surface onto which it rests. The
coefficient of static friction can then be determined by taking the
ratio of the static friction force to the normal force, which is
equal to the weight of the known mass placed onto the testing sled.
The kinetic friction force can be determined by taking the average
imparted force after the testing sled begins to move. In plot 500,
the kinetic friction force is shown by force line 504. The
coefficient of kinetic friction can then be determined by taking
the ratio of the kinetic friction force to the normal force.
[0061] FIG. 6 shows a plot 600 that compares the static and kinetic
coefficients of friction obtained using the testing scheme
discussed above with respect to FIG. 5, for sheets of the material
100 having different patterns of movable projections. The testing
done to obtain plot 600 used a sheet of material with
concave-shaped movable projections made from polyester plastic. The
sheet of material was tested on an icy surface. Bar 602A shows the
static coefficient of friction for movable projections arranged in
the 1Dir pattern, while bar 602B shows the kinetic coefficient of
friction for movable projections arranged in the 1Dir pattern. Bar
604A shows the static coefficient of friction for movable
projections arranged in the 3Col pattern, while bar 604B shows the
kinetic coefficient of friction for movable projections arranged in
the 3Col pattern. Bar 606A shows the static coefficient of friction
for movable projections arranged in the 16.times.2 pattern, while
bar 606B shows the kinetic coefficient of friction for movable
projections arranged in the 16.times.2 pattern.
[0062] Bar 608A shows the static coefficient of friction for
movable projections arranged in the Half pattern, while bar 608B
shows the kinetic coefficient of friction for movable projections
arranged in the Half pattern. Bar 610A shows the static coefficient
of friction for movable projections arranged in the Checker
pattern, while bar 610B shows the kinetic coefficient of friction
for movable projections arranged in the Checker pattern. Finally,
bar 612A shows the static coefficient of friction for a control
with no movable projections, while bar 612B shows the kinetic
coefficient of friction for a control with no movable
projections.
[0063] Plot 600 illustrates that the presence of the movable
projections in the second orientation increased the friction on the
icy surface relative to the control, regardless of which pattern of
movable projections was used. The 16.times.2 pattern resulted in
the largest static coefficient of friction, while the 3Col pattern
resulted in the largest kinetic coefficient of friction.
[0064] FIG. 7 shows a plot 700 that compares the static and kinetic
coefficients of friction obtained using the scheme discuss above
with respect to FIG. 5, for sheets of the material 100 having
movable projections with different shapes. The testing done to
obtain plot 700 used a sheet of material with movable projections
made from plastic polyester and arranged in the 16.times.2 pattern.
The sheet of material was tested on an icy surface. Bar 702A shows
the static coefficient of friction for concave-shaped movable
projections, while bar 702B shows the kinetic coefficient of
friction for the concave-shaped movable projections. Bar 704A shows
the static coefficient of friction for convex-shaped movable
projections, while bar 704B shows the kinetic coefficient of
friction for the convex-shaped movable projections. Bar 706A shows
the static coefficient of friction for rectangular movable
projections, while bar 706B shows the kinetic coefficient of
friction for the rectangular movable projections.
[0065] Bar 708A shows the static coefficient of friction for
triangular movable projections, while bar 708B shows the kinetic
coefficient of friction for the triangular movable projections. Bar
710A shows the static coefficient of friction for barbed-shape
movable projections, while bar 710B shows the kinetic coefficient
of friction for the barbed-shape movable projections. Finally, bar
712A shows the static coefficient of friction for a control with no
movable projections, while bar 712B shows the kinetic coefficient
of friction for a control with no movable projections.
[0066] Plot 700 illustrates that the presence of the movable
projections in the second orientation increased the friction on the
icy surface relative to the control, regardless of what the shape
of the movable projections is. The triangular movable projections
resulted in the largest static and kinetic coefficients of
friction, thus demonstrating the greatest friction increase
relative to the control. Thus, in some implementations, the
material 100 can have triangular movable projections that are
arranged in the 3Col pattern or the 16.times.2 pattern.
[0067] The terminology used herein is for the purpose of describing
particular embodiments only, and is not intended to be limiting of
the invention. As used herein, the singular forms "a," "an," and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. Furthermore, to the extent
that the terms "including," "includes," "having," "has," "with," or
variants thereof, are used in either the detailed description
and/or the claims, such terms are intended to be inclusive in a
manner similar to the term "comprising."
[0068] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art. Furthermore, terms,
such as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art, and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
[0069] One or more elements or aspects or steps, or any portion(s)
thereof, from one or more of any of claims 1-52 below can be
combined with one or more elements or aspects or steps, or any
portion(s) thereof, from one or more of any of the other claims
1-52 or combinations thereof, to form one or more additional
implementations and/or claims of the present disclosure.
[0070] While various embodiments of the present invention have been
described above, it should be understood that they have been
presented by way of example only, and not limitation. Numerous
changes to the disclosed embodiments can be made in accordance with
the disclosure herein, without departing from the spirit or scope
of the invention. Thus, the breadth and scope of the present
invention should not be limited by any of the above described
embodiments. Rather, the scope of the invention should be defined
in accordance with the following claims and their equivalents.
[0071] Although the invention has been illustrated and described
with respect to one or more implementations, equivalent
alterations, and modifications will occur or be known to others
skilled in the art upon the reading and understanding of this
specification and the annexed drawings. In addition, while a
particular feature of the invention may have been disclosed with
respect to only one of several implementations, such feature may be
combined with one or more other features of the other
implementations as may be desired and advantageous for any given or
particular application.
* * * * *