Custom insert with a reinforced heel portion

A midsole (12 and 24) for an activewear shoe (10) comprises a removable insert (12) and a peripheral member (24). The peripheral member (24) is joined to the perimeter of an upper surface (20) of an outsole (16). A plurality of independent cushioning elements (40) depend from a base member (38) of insert (12), and are sized in order to conform to the depth of peripheral member (24). A window (14) is formed through the peripheral member (24) and/or the outsole (16) to allow observation of the insert (12) from exterior the shoe (10). To reinforce the peripheral member (24) proximate the window (14), a row of stiffened cushioning elements (62) is formed on the insert (12). The stiffened elements (62) have a higher durometer reading than the remaining elements (40) and are formed during an injection molding process. A transverse reinforcing segment (31) may be provided to inhibit movement of the insert (12) within the shoe (10). If desired, the segment (31) and the elements (40) may be formed with cavities therein to lighten the weight of the shoe (10).

TECHNICAL FIELD OF THE INVENTION 
This invention relates in general to athletic or other activewear shoes, 
and more particularly to shoes having custom midsoles with a removable 
insert that has a reinforced heel portion to provide added support to the 
wearer. 
BACKGROUND OF THE INVENTION 
Athletic or other activewear shoes of a conventional construction generally 
have three or four separate parts. First, such shoes are generally 
provided with an outsole made of a durable material and which extends 
across the lower surface of the shoe. A midsole is joined to the outside 
to provide a cushioning layer to the wearer's foot. Usually, an upper 
formed of leather, synthetics or other materials is joined to the midsole. 
In many conventional structures, an insole is further positioned between 
the midsole and the wearer's foot for additional cushioning. 
The midsoles of these conventional constructions have two undesirable 
characteristics. First, they have the property of deforming over a large 
area of surface when a downward force is impressed on them. Second, the 
midsoles are affixed to the shoes and therefore customers can make no 
choice in the midsole's cushionability without selecting another shoe. 
Thus, conventional midsoles do not offer independent suspension or 
deformation of various selected areas thereof, and further are suited to 
only a particular weight class or cushionability preference of wearers. 
The need for a midsole having a plurality of cushioning elements, each 
demonstrating an individual suspension and deforming independently from 
the remaining elements has generally been met by the custom midsole as 
disclosed in U.S. Pat. No. 4,733,483, Mar. 29, 1988, to Lin, and assigned 
to the present assignee. However, a need has arisen for a midsole which 
can be better tailored for specific support. Moreover, it is desirable to 
provide a see-through window that allows observation of the midsole. 
Unfortunately, a window in the sole of a shoe may result in weakening of 
that portion of the sole. Thus there is a need for a custom midsole that 
may reinforce the weakened window portion of a sole, while also 
counteracting the tendency of a wearer to pronate or supinate. 
SUMMARY OF THE INVENTION 
The present invention disclosed herein comprises a method and apparatus for 
an improved midsole insert having a reinforced heel portion which 
substantially eliminates or reduces problems associated with prior midsole 
inserts. The present invention reinforces the heel portion of an insert to 
counteract and reinforce the weakening of an area of the shoe caused by 
the insertion of an observation window therethrough. The present inventin 
also helps in counteracting pronation or supination by the wearer. 
In accordance with one aspect of the invention, a bottom surface of a shoe 
insert is provided with a plurality of individual cushioning elements. A 
row or area of the elements is stiffened along one edge of the insert to 
provide additional edge support. 
In another aspect of the present invention, a shoe having an edge weakened 
by the insertion therein of a see-through observation widow is reinforced 
by the stiffened row of elements. Alternatively, the stiffened row of 
elements may be positioned to counteract the effects of pronation or 
supination. 
It is a technical advantage of the present invention that a shoe having a 
weakened area therein by the addition of an observation window may be 
strengthened. It is a further technical advantage that a tendency of the 
wearer to pronate or supinate may be counteracted.

DETAILED DESCRIPTION OF THE INVENTION 
Referring first to FIG. 1, an isometric view of a shoe constructed in 
accordance with the preferred embodiment of the present invention is 
generally indicated by the reference numeral 10. A custom midsole insert 
12 is shown fitted into an active wear shoe with an observation or 
see-through window 14 for viewing the insert 12 from external the shoe 10. 
While the illustrated shoe 10 is designed for walking, the invention can 
also be employed in other types of athletic shoes, such as running, 
aerobics, or court shoes. 
The shoe 10 comprises an outsole 16 that forms the wearing surface of the 
shoe. The outsole 16 is preferably constructed of a relatively durable, 
resilient material such as natural rubber. The outsole 16 has an exterior 
surface that is provided with a suitable tread surface 18 and an interior 
or upper surface 20. The upper surface 20 may be smooth and featureless 
throughout, or may have a central area 22 that is reticulated or webbed in 
order to save weight. A peripheral area (not shown) of the upper surface 
20 presents a smooth surface for gluing or other means of attachment. 
A peripheral midsole member 24 is formed to be glued or otherwise attached 
to the peripheral area of outsole upper surface 20. Peripheral member 24 
is more cushionable and yielded than outside 16, and can be conveniently 
molded of polyurethane foam or ethylene vinyl acetate copolymer (EVA). 
Peripheral member 24 has an interior sidewall 26 and an upper surface 28. 
Peripheral member 24 in the illustrated embodiment, extends around the 
periphery of outsole 16 and is interrupted only by the see-through window 
14 which is constructed in accordance with the disclosure in co-pending 
U.S. application Ser. No. 245,758 which is incorporated herein by 
reference. The peripheral member 24 is weakened by removal of a portion 
thereof necessary to insert the window 14. Thus, in an important aspect of 
the present invention, it is desirable to provide added support to the 
shoe 10 proximate the window 14 as will be subsequently described in 
greater detail. It may also be desirable to extend a portion 29 of the 
outsole 16 over a portion of the window 14 to help strengthen the shoe 10. 
Preferably, a footbed reinforcing layer 30 is affixed as by gluing to the 
outsole upper surface 20. The layer 30 is preferably thinner than the 
height of the peripheral member 24 to allow room for the insert 12. The 
reinforcing layer 30 is sized to substantially coincide with the exposed 
portion of the outsole upper surface 20. 
The layer 30 is fabricated of a relatively resilient, firm and less 
flexible material than the EVA forming the peripheral member 24, for 
example, a leatherized paper or cardboard. The purpose of the layer 30 is 
to replace torsional strength lost by the creation of the peripheral 
midsole member 24. Thus, a midsole/outsole configuration having 
satisfactory torsional strength is formed for proper lateral support of 
the wearer's foot while at the same time providing for a central insert 12 
having selectable cushionability. 
A transverse reinforcing segment 31 may be formed in accordance with the 
disclosure in co-pending U.S. application Ser. No. 245,758. The segment 31 
may have a plurality of cavities 33 (only one of which is shown) formed 
therein to lighten the overall weight of the shoe 10 without detracting 
from the stability and support function of the segment 31. 
The peripheral member 24 forms a receptacle 32 (divided by segment 31) that 
is diemnsioned to receive the insert 12. The shoe 10 further comprises an 
upper 34 that can be fashioned of leather, cloth, synthetic materials or a 
combination of these, and is attached to the upper surface 28 of the 
peripheral member 24. 
The insert 12 comrpises an upper base member 38 and a plurality of 
supporting elements 40 that are preferably formed integrally with base 
member 38 to depend therefrom, as further shown and described in 
co-pending application Ser. No. 245,758. As shown, the elements 40 occupy 
the receptacle 32 when the insert 12 is installed into the shoe 10. The 
elements 40 are dimensioned such that their depth matches the depth of the 
sidewall 26 minus the thickness of the layer 30, and are formed to occupy 
substantially all of the receptacle 32 from one sidewall 26 to the other. 
The peripheral member 24 and the removable insert 12 are apportioned such 
that most of the weight of the wearer will be borne by the insert 12. Of 
primary importance to the present invention, certain ones of the elements 
40 are formed from a material that has a higher durometer reading (i.e., 
they are stiffer) than the rest of the elements 40, as will be 
subsequently described in greater detail. 
The insert 12 has a transverse slot 41, formed by eliminating certain ones 
of the elements 40, corresponding to the transverse reinforcing segment 
31. The base member 38 has an upper surface 44 onto which a flocking 
material 46, which is preferably formed of a polyester/nylon material but 
can be formed of any suitable fabric, is joined as by gluing. When 
finished out by the flocking material 46, the insert 12 does not require 
any insole or liner on top of it to be suitable for wearing. 
As shown, base member 38 has a central member 48, and a lip member 50 
extending beyond the central area 48 with the cushioning elements 40 
depending therefrom. The lip member 50 is formed to be coextensive with 
the top surface 28 of the peripheral member 24 to present a cushional 
upper surface 44 to the wearer's foot. 
Referrig now to FIG. 2, a bottom isometric view of insert 12 is shown. In 
the illustrated embodiment, insert 12 is integrally formed with an insole 
portion 52. In the embodiment shown in FIG. 2, the upper surface 44 
comprises the upper surface of the insole portion 52, and the flocking 
material 46 (FIG. 1) is joined to this surface. 
The elements 40 each take the form of a pillar with a rounded free end, 
although it will be understood that the elements could have different 
configurations. The elements 40 are formed in the central area 48 in a 
close packing arrangement in order to provide cushionable support 
throughout the central area 48. The elements 40 are formed independently 
of each other, and are joined only to the base 38. In this manner, the 
elements 40 provide a multiple-point independent suspension. This is 
because the elements 40 will be compressed and will yield independently of 
each other. This is an advantage over midsoles or insoles of solid 
construction, which have a tendency to yield and compress continuously and 
uniformly over large areas. The discrete elements 40 on the other hand 
give an independent, discontinuous support to different portions of the 
foot that is not obtainable by a midsole or insole of uniform 
construction. 
The elements 40 are graduated in size in order to conform to the depth of 
the the sidewall 26 (FIG. 1) and to provide different cushioning 
characteristics. In a front area 54 of the area 48, a plurality of 
relatively small elements 56 conform to the relatively thin depth of the 
peripheral member 24. In a heel region 58, a relatively small number of 
large heel cushioning elements 60 are formed. The larger size of the 
elements 60 adapts them to the larger depth of the peripheral member 24 in 
the heel region 58. Further, since there is a larger cushioning depth of 
material, the larger size of the elements 60 prevents undue bending or 
nonradial deformation, as might otherwise occur if a greater member of 
long, thin elements were used. 
Of primary importance to the present invention, as previously mentioned 
above, is that certain ones of the elements 40 are made stiffer than the 
remaining elements 40. In the embodiment shown in FIG. 2, a row of stiffer 
elements 62 is formed along an outside edge 64 corresponding to the window 
14 formed in the peripheral member 24 (FIG. 1). Since it was necessary to 
remove a portion of the peripheral midsole member 24 to install the window 
14, the strength of the midsole member 24 is correspondingly reduced. Thus 
it is preferable to provide stiffer elements 62 as a substitute for the 
removed midsole portion. 
The stiffer elements 62 comprise, for example, polyurethane having a higher 
durometer than any of the other elements 40. The elements 62 are 
preferably formed integrally with the elements 40 in an injection molding 
process. Alternatively, the insert 12 may be constructed of two parts, 
each part formed from different materials of different stiffness, and the 
two parts being glued together to form an integral insert. If desired, it 
is possible to lighten the overall weight of the shoe 10 and the insert 12 
by forming generally cylindrical cavities 63 in each of the elements 40. 
Although not shown, it is to be understood that the cavities 63 may have 
other shapes such as conical or spherical. 
Referring to FIG. 3, an alternative embodiment of the custom midsole 12 is 
illustrated. The midsole 12 is constructed and arranged to place the 
stiffer elements 62 along an inside edge 66 of the shoe 10 rather than 
along the outside edge 64. Such an arrangement could be used in any shoe 
having an insert to counteract the tendency to pronate. It will be 
understood that other configurations could be formed with stiffer elements 
oriented in a variety of designs. 
In operation, shoes 10 and inserts 12 may be distributed to retailers as 
separate items. Each insert 12 has a specific durometer reading that 
measures the relative yieldability or resiliency of the elements 40. If 
the insert 12 is to be used with a window 14 (or any other weakened 
peripheral midsole member 24) a row of stiffer elements 62 having a higher 
durometer than the elements 40 is provided to strengthen the area around 
the window 14. If no window is used but a customer wants to counteract 
supination, a row of stiffer elements 62 may be positioned along the outer 
edge 64 of the insert 12. If the wearer wants to counteract the effects of 
pronation, a row of stiffer elements 62 may be placed along the inner edge 
66 of the insert 12. 
In summary, a novel midsole with a custom insert has been provided in order 
to vary the resiliency and cushionability of the midsole according to the 
wearer's needs and to support the inner or outer edge of the shoe. A 
stiffer row of elements is properly positioned in the heel region of the 
insert to reinforce the weakened area around an observation window. 
Additionally, stiffer elements may be positioned to counteract pronation 
or supination. 
While preferred embodiment of the invention and their advantages have been 
described above, the invention is not limited thereto but only by the 
spirit and scope of the claims which follow.