Modular Insert System for Shoe Soles
A support customising system is described for a sole 1 of a shoe. The sole 1 comprises a relatively soft, resilient midsole 3 and an a harder outsole 4. Hard insert elements 5 are provided for inserting into vertical cavities 2 in the midsole 3. By varying the hardnesses of different inserts 5 in different vertical cavities, a precisely-tunable pronation control effect on the wearer's gait can be effected. First-order, second-order and third-order pronation control effects are described.
The present invention relates to soles for articles of footwear, in particular footwear for correcting, supporting or accommodating the gait of the wearer.
BACKGROUND ARTIn addition to providing general support for the wearer's feet while walking or running, shoe soles can be manufactured such that the degree of support for the foot differs between different regions of the sole. Thus the material of the heel region, for example, which experiences the greatest impact forces, is often manufactured to provide greatest impact cushioning effect. The desired variation in support may be achieved for example by varying mechanical properties of the material of the sole, such as the shape, thickness, density, hardness and flexural characteristics. In this way, the sole may be manufactured so as to provide optimum support for the typical wearer's feet. Since gait characteristics vary significantly from person to person, footwear manufacturers design the soles of their products to cater for a broad range of gait types, based around a putative norm. Soles may also be configured to suit different types of use. For example, soles may be configured for sprinting, long-distance running, playing particular sports such as golf or tennis or cross-country skiing, or for casual wear. Running shoes require different sole configurations for different distances, and for different types of terrain.
The wearer is therefore obliged either to settle for a sole which will cover a wide range of uses, but will not be well configured for any of those uses, or he may purchase different footwear for different uses; different shoes for road-running and for cross-country running, for example, or different shoes for different distances.
Specialist soles are also available which are configured to accommodate or correct particular types of gait, such as over-pronation or supination. Shoes are also available with soles which are customised to a particular combination of gait-type, or sport, or use. It is possible to have soles customised for a particular person, or even for a particular foot. However, bespoke soles are expensive, and the present invention is concerned primarily with soles for footwear which can be manufactured and distributed in significant numbers as a commercial retail product.
It has been suggested to provide a certain customisability of the support provided to a wearer's foot by means of an orthotic insole, laid on top of the integral sole of a shoe. Such insoles may incorporate regions of different support, which are arranged to suit the particular use or gait-type. The hardness of the regions may be customised by exchanging portions of the orthotic, for example. Such a customisable orthotic is known from EP2383952, in which a shaped piece of the orthotic can be exchanged for a similarly-shaped piece having a different hardness. The orthotic described in this document thus provides a limited customisability of the support which is provided by the insole.
EP1352579 describes a midsole comprising regions of different hardnesses, so that the midsole can be customised for a particular wearer. The assembled portions of the midsole may be formed into a continuous moulding, in which case the customised sole is no longer customisable. Alternatively, the assembled portions can remain as discrete components of the sole, in which case the mechanical integrity of the sole as a whole is greatly reduced.
DE20320091 describes an adaptable insert which affords a limited customisability of the support provided at a particular region of the sole. The insert is introduced from the medial side of the sole (ie left-hand side of a right shoe or right-hand side of a left shoe) or the lateral side of the sole (ie right-hand side of a right shoe or left-hand side of a left shoe), and is held in place using a clip. The insert also includes vertical hexagonal-shaped holes into which can be inserted hexagonal pegs of a particular hardness. In this way, the effective hardness of the insert can be varied by inserting pegs which are harder than the material of the insert, which gives the wearer some control over the degree of support provided at that particular region of the sole when the insert is located in position. The midsole is provided with a wide horizontal cavity, open to one side, into which the insert can be pushed. The presence of a wide cavity reduces the overall mechanical integrity of the sole, even with the insert in place, and provides a path for water and dirt to enter the sole, and to work their way deep within the sole. The presence of the midsole material above and below the cavity means that the effectiveness of the lateral insert is reduced, in that the amount of vertical support it provides is reduced, and the total amount of vertical support provided may the sole in the region of the insert can be less accurately defined. Over time, the material of the midsole above and below the cavity, and the material of the insert element surrounding the pegs, will lose elasticity and resilience due to the repeated compression during the gait cycle. Such insert elements are typically positioned in regions of the sole where greater support is required, which means that the repeated compression, and the consequent crushing of the insert material and the midsole material above and below the insert, will be particularly susceptible to degradation, and thereby shorten the wearable life of the shoe.
In view of the limited customisability of prior art soles such as those described above, there is a need for a sole which is suitable for mass production, yet which can afford a high degree of individual customisability without significantly compromising the mechanical integrity of the sole as a whole. A further need exists for a customisable, mass-producable sole in which the rate at which the midsole material becomes irreversibly crushed through repeated gait cycles is reduced.
DISCLOSURE OF INVENTION Brief Description of the InventionThe invention described in this application seeks to overcome at least some of the above and other disadvantages inherent in the prior art. In particular, the invention aims to provide a customisable sole system according to claim 1, a sole according to claim 17, a plurality of support adjustment elements according to claim 18 and a method according to claim 19.
A support customising system is described below for the sole of a shoe or other article of footwear. The sole comprises a relatively soft, resilient midsole and (optionally) a harder outsole. Hard insert elements are provided for inserting into vertical cavities in the midsole. By varying the hardnesses of different inserts in different vertical cavities, a precisely-tunable pronation control effect on the wearer's gait can be effected. First-order, second-order and third-order pronation control effects are described. The invention and its advantages will further be explained in the following detailed description, together with illustrations of example embodiments and implementations given in the accompanying drawings. Note that the drawings are intended merely as illustrations of embodiments of the invention, and are not to be construed as limiting the scope of the invention. Where the same reference numerals are used in different drawings, these reference numerals are intended to refer to the same or corresponding features. However, the use of different reference numerals should not in itself be taken as an indication of any particular difference between the referenced features. In this description the terms hardness and durometer are used interchangeably, and numerical hardness values refer to the Shore A hardness scale.
An example of a support customising system according to the invention is illustrated in
The example sole 1 illustrated in
The inserts 5 may also be made of an elastomeric material, for example, and they may have different hardnesses from the midsole 3 and/or from one another. Some of the inserts 5 may have substantially the same hardness as the material of the midsole 3, in order to provide a null support adjustment at a particular cavity 2. It is also possible to provide inserts 5 with lower hardnesses than the midsole 3; this may for example be useful for providing a negative support adjustment in a particular region of the sole 1 by reducing the average hardness of the region by inserting one or more inserts 5 which are softer than the material of the surrounding midsole 3.
The hardnesses of the inserts 5 may be selected from a set of predetermined hardnesses. For example, a pair of shoes having soles such as that illustrated in
When the wearer puts weight on the sole, for example while walking, the inserts 5 which are harder than the surrounding midsole material serve to transfer a force from between the ground and the wearer's foot which is greater than that transferred by the surrounding midsole material. Each of these harder inserts thereby provides increased support for the wearer's foot at the location in the sole at which it is inserted. Because the inserts 5 each have one of a predetermined set of hardnesses, at least in the vertical direction, and because they extend along substantially the whole vertical depth 11 of the sole 1, or at least substantially the whole depth 11 of the midsole 3, the net vertical hardness of the sole 1 at the location of each cavity 2 is determined exclusively, or in a great majority, by the hardness of the particular insert 5. The hardness of the outsole 4, if it is different from the hardness of the insert 5, may also contribute an effect to the net vertical hardness of the sole 1 at that location, but the contribution may be small, particularly if the outsole 4 is thin and/or the hardness difference between the outsole 4 and the insert 5 is small. Similarly, the contribution of the insole 6 or any minor part of the midsole which extends above or below the insert 5 when the insert 5 is inserted, will also have only a small effect on the net vertical hardness of the sole 1 at the particular cavity. The term net vertical hardness is used here to indicate a measure of the compressibility and resilience of the sole in an approximately vertical direction (ie as measured along the vertical axis 8).
The vertical cavities 2 and the inserts 5 shown in the example of
Because the inserts 5 are oriented substantially vertically in the midsole 3, and because they have relatively small lateral dimensions, multiple inserts 5 and cavities 2 can be located in a particular region of the sole 1 in order to adjust the net vertical hardness of sole with a fine resolution. Thus, a pronation control zone in the forefoot area 12 of the sole 1 may incorporate multiple (eg three to ten inserts), for example, each with a hardness suitable for the pronation control requirement of the wearer. The hardnesses of the three to ten inserts 5 may be the same, or they may be graded. For example, the hardnesses of the inserts may be increased from the rear-most insert 5 to the foremost insert 5.
The discussion above has related primarily to the inserts 5 and cavities 2 of a single shoe. In a pair of shoes, the inserts 5 and cavities 2 may similarly be made so that the same inserts 5 can be used in the cavities 2 of either shoe. The support customising system may be arranged such that, multiple pairs of shoes can share the same set of support adjustment inserts 5.
The use of multiple, interchangeable inserts 5 having different hardnesses means that the support provided by the sole 1 can be finely tuned to the needs of the wearer. The support may be differently tuned between the left shoe and right shoe, between different regions 12, 13, 14 of one sole 1, or even within the same region of the sole 1.
In the example configuration of
Left and right feet naturally have slightly different pronation styles, due to the natural asymmetry in the person's posture and due to neurological effects which gives rise to asymmetries in gross motor control, reflected in the person's posture and gait.
Because the inserts 5 of a particular region, or of multiple regions of the sole, may have the same cross-sectional shape, the inserts 5 may be made interchangeable between all cavities 2 of a particular region or between all cavities 2 of the sole. In this case many different configurations of the support offered by the sole can be achieved with a relatively modest number of inserts 5.
Each insert 5 may be formed as a single contiguous piece of material, or it may be formed from two or more constituent pieces. It may be solid, for example to assure its rigidity, or it may be hollow, for example to cut down on shoe weight and material costs. It may be open at one or both ends, and it may have openings in its side wall(s).
Also illustrated in
The multiple cavities 2 may advantageously have the same size and shape, as illustrated in
Medial and lateral control regions 21 and 22 can be used to control the amount of pronation during the initial phase of the gait cycle (ie following initial heel impact). By judicious choice of the hardnesses of the inserts 51 of the medial region 21 and the hardnesses of the inserts 51 and 52 of the medial 21 and lateral 22 control regions, it is possible to influence the degree of pronation of the foot around the stability ‘S-line’ 20. Furthermore, the use of inserts 5 of graded hardnesses in a particular region permits a second-order control, in which not only the amount of pronation can be controlled, but also the rate of change of pronation with respect to the forward motion of the foot during the sole's contact with the ground when walking or running. Taking the six medial control inserts 51 illustrated in
The lateral and medial inserts 51 and 52 can further be used to achieve a third-order control effect, in that inserts can be selected to vary the rate of pronation. If the lateral control region 22 is provided with more cavities and inserts 52, (say five inserts in a line running parallel to the heel-toe axis, for example), then the hardnesses of the five lateral inserts 52 can be chosen so as to vary the rate pronation along the heel-to axis. Thus, by being able to select the hardnesses of the lateral inserts 52 it is possible not only to vary the amount of pronation (first-order effect), but also to vary the rate at which pronation occurs (second order effect) and the axial variation in the rate of pronation (third-order effect).
By using many cavities/inserts, it is possible to vary the pronation/supination control with a fine resolution, and in many different ways. For example, it is possible to take set the hardness of the inserts 5 to take account of individual bones or bone groups in the foot. Excessive calcaneal/talal tilt can be compensated for, for example, while minimising the effect on the metatarsal or forefoot regions.
The control effects described above in relation to the interchangeable inserts 52 of the lateral region 22 also apply to the other illustrated regions in
As a consequence of such finely-adjustable and adaptable gait control, it is possible to improve the wearer's gait and straighten the wearer's axial skeleton, which not only has beneficial effects for the wearer, but also promotes even wear on the outsoles 4 and therefore extends the life of the shoes.
Furthermore, if the individual inserts are replaceable, then the soles can be ‘tuned’ for different uses, or for different wearers, or as the shoes age, or as the wearer's gait changes.
The following examples illustrate the insert hardnesses which could be chosen for different gait control purposes. The examples are based on a sole configuration similar to that shown in
Lateral control region 22: 50 Shore, 60 Shore, 60 Shore
Medial control region 21: all 50 Shore or less
Forefoot lateral control region 23: all 60 Shore
Example 2: For Correcting a Delayed OverpronationLateral control region 22: all 50 Shore (no correction)
Medial control region 21: 50, 60, 70, 80, 80, 60 Shore
Forefoot lateral control region 23: all 60 Shore
Example 3: For Correcting Severe General OverpronationLateral control region 22: 50, 50, 60 Shore
Medial control region 21: 70, 80, 90, 80, 70, 60 Shore
Forefoot lateral control region 23: all 60 Shore
Example 4: For Correcting Early, Slight OverpronationLateral control region 22: 50, 50, 60 Shore
Medial control region 21: 70, 60, 50, 50, 50, 50 Shore
Forefoot lateral control region 23: 70, 60, 50, 50, 50 Shore
Example 5: For Correcting Delayed, Slight OverpronationLateral control region 22: all 50 Shore (no correction)
Medial control region 21: 50, 50, 60, 60, 70, 70 Shore
Forefoot lateral control region 23: all 50 Shore (no correction)
A second example sole layout is shown in
The inserts 5 may be secured in the cavities 2 by any suitable means. If an insert is intended to remain in its cavity permanently, then it may be glued or bonded or welded in place in the cavity 2. The insert 5 may even be supplied as a liquid which can be introduced into the cavity 2 and which then sets with a predetermined hardness.
The cavities 2 may also be angled in a longitudinal direction, as shown in
Inserts 5 may be made so that they can be pushed into the midsole 3 by hand, for example.
In order to insert and/or remove the inserts 5 into or out of the cavities 2, the inserts 5 may be provided with pulling engagement means for withdrawing the insert by pulling, or rotational driving engagement means for screwing the insert 5 into or unscrewing the insert out of the cavity 2. Two example arrangements are illustrated in
If an insert is made from two or more insert sub-pieces, then the individual sub-pieces may each form a portion of the cross-section of the insert, for example, each extending over the vertical length 11 of the insert 5, or they may each form a portion of the vertical length 11 of the insert, such that the insert 5 is formed from two or more insert sections arranged along the vertical axis. An example of such an insert 5 is shown in
The compound insert 5 of
Claims
1. Pronation control customising system for an article of footwear, the system comprising:
- a sole comprising a midsole of a first material having a first durometer, the midsole having an upper, foot-facing surface and a lower, ground-facing surface,
- a plurality of vertical cavities in a first region of the midsole, each vertical cavity extending along a vertical axis substantially orthogonally to the upper surface, between the lower and the upper surfaces of the midsole, and
- a plurality of support adjustment elements, for each being substantially wholly inserted into one of the vertical cavities so as to adjust a vertical support hardness of the sole at the location of said each vertical cavity;
- wherein each vertical cavity comprises a insertion opening in the upper surface and/or in the lower surface for receiving one of the support adjustment elements, and
- wherein the plurality of support adjustment elements comprises a first support adjustment element having a second durometer and a second support adjustment element having a third durometer, different from the second durometer, wherein at least one of the second and third durometers is greater than the first durometer,
- wherein the cavities and support adjustment elements are each configured such that the net vertical hardness of the sole at the location of each cavity is determined in a great majority by the hardness of the particular insert in the cavity, and
- wherein the cavities and support adjustment elements are arranged for pronation control such that a first plurality of the vertical cavities is arranged in a first pronation control region of the sole, and a second plurality of the vertical cavities is arranged in a second pronation control region of the sole, the first and second pronation control regions being on medial and lateral sides, respectively, of the ideal gait line of the sole.
2. System according to claim 1, wherein each of the first and second support adjustment elements, when inserted into a first one of the vertical cavities, and the plurality of vertical cavities have substantially the same cross-section as the first vertical cavity in a horizontal plane parallel to the upper and or lower surface, such that the first and second support adjustment elements are interchangeably insertable into the first vertical cavity through the insertion opening of the first vertical cavity.
3. System according to claim 1, wherein the first support adjustment element, the second support adjustment element and a first one of the plurality of vertical cavities have substantially the same vertical length along the vertical axis.
4. System according to claim 1, wherein the first and second support adjustment elements and the plurality of vertical cavities each has a substantially constant cross-section along at least a majority of its vertical length.
5. System according to claim 1, wherein:
- the first and second support adjustment elements each comprises a first protrusion arranged on a lateral outer wall of said first or second support adjustment element;
- and/or
- the first vertical cavity comprises a second protrusion arranged on a lateral inner wall of the first vertical cavity;
- wherein the first and/or second protrusions are configured to provide a positive-fit or friction grip between the lateral outer wall of said first or second support adjustment element and the inner wall of the first vertical cavity, for resisting a movement of said first or second support adjustment element in the first vertical cavity along the vertical axis in a withdrawal direction of the first and/or second support adjustment elements from the first vertical cavity.
6. System according to claim 5, wherein the first and/or second protrusion is formed as a screw thread.
7. System according to claim 1, wherein one or more of the support adjustment elements (5) comprises engagement purchase means formed at an end of said each support adjustment element, wherein:
- the engagement purchase means is configured for providing a pulling purchase for withdrawing the support adjustment element from within one of the vertical cavities along the vertical axis of the vertical cavity,
- and/or
- the engagement purchase means is configured for providing rotational driving purchase for driving a rotation of the support adjustment element about the vertical axis of the vertical cavity when the support adjustment element is inserted into the vertical cavity or when the support adjustment element is being withdrawn from the vertical cavity.
8. System according to claim 1, wherein the first and/or second support adjustment elements comprise a sensory-motoric stimulus protrusion configured to protrude proud of the upper surface when said first and/or second support adjustment element is fully inserted in one of the vertical cavities, the proudness of the sensory-motoric stimulus protrusion being configured to provide a sensory-motoric load-response stimulus to a wearer's foot at the location of the said first or second support adjustment element.
9. System according to claim 1, wherein each support adjustment element, when fully inserted into a corresponding one of the vertical cavities, extends along substantially the whole vertical depth of the midsole.
10. System according to claim 9, wherein the first and second pluralities of vertical cavities and the plurality of support adjustment elements have substantially the same cross-section, such that the first plurality of support adjustment elements can be fittedly inserted into the vertical cavities of the first and second pluralities.
11. System according to claim 1, in which the second durometer is at least 5 Shore greater than the first durometer.
12. System according to claim 1, in which the third durometer is at least 5 Shore greater than the second durometer.
13. System according to claim 1, in which the second durometer is less than or equal to the first durometer.
14. System according to claim 1, in which the sole comprises an outsole, below the lower surface of the midsole, the outsole having a fourth durometer greater than the first durometer.
15. System according to claim 14, wherein at least one of the vertical cavities is closed at its lower end by the outsole.
16. System according to claim 14, wherein at least one of the vertical cavities comprises a lower insertion opening, extending through the outsole, for receiving one of the support adjustment elements.
17. An article of footwear comprising the sole of claim 1.
18. The plurality of support adjustment elements of claim 1.
19. A method of using the system of claim 1, the footwear of claim 17 or the support adjustment elements of claim 18 to customise the pronation control provided to a wearer's foot by the sole, the method comprising the steps of:
- determining a pronation control requirement of the wearer's foot,
- based on the pronation control requirement, selecting said first and second support adjustment elements from said plurality of support adjustment elements,
- based on the pronation control requirement, selecting said first vertical cavity, wherein the first vertical cavity is located in a third gait control region for adjusting the pronation control provided by the sole to the wearer's foot for meeting the pronation control requirement,
- inserting one of the first and second support adjustment elements into said first vertical cavity.
20. Method according to claim 19, further comprising the step of inserting the other of the first and second support adjustment elements into a second vertical cavity in said third gait control region or in a fourth gait control region, different from the third gait control region.
Type: Application
Filed: Dec 12, 2014
Publication Date: Nov 23, 2017
Inventors: Harald Beck (Uster), Tobias Schumacher (Langenthal)
Application Number: 15/535,406