SYSTEMS AND METHODS FOR ADJUSTING FRICTION
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.
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 FIELDThe 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.
BACKGROUNDAccidental 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.
SUMMARYAccording 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.
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.
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.
The disclosure will be better understood from the following description of exemplary embodiments together with reference to the accompanying drawings.
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 DESCRIPTIONThe 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.
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.
The zoomed-in inset view of
As can be seen in the zoomed-in inset views of both
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.
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
Referring now to
Referring now to
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
Referring now to
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
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).
Moreover, similar to the pattern in
It is further noted that
Referring now to
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
Similar to the patterns in
Referring now to
Similar to the patterns in
Referring now to
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
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
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.
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®) 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.
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.
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.
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.
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 16×2 pattern resulted in the largest static coefficient of friction, while the 3Col pattern resulted in the largest kinetic coefficient of friction.
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.
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 16×2 pattern.
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.”
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.
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.
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.
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.
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.
Type: Application
Filed: Oct 8, 2021
Publication Date: Apr 14, 2022
Inventors: Robert S. Langer (Cambridge, MA), Katia Bertoldi (Cambridge, MA), Carlo Giovanni Traverso (Boston, MA), Sahab Babaee (Cambridge, MA), Ahmad Rafsanjani Abbasi (Cambridge), Simo Pajovic (Cambridge, MA)
Application Number: 17/497,380