United States Patent 3670429

A sole for an article of footwear comprises a heel portion composed of resilient material and a toe portion. A cavity is provided in the resilient heel portion and air passages extend interiorly of the sole from the heel portion to the toe portion and opEn at the heel end into the cavity. A series of toe openings are provided in the toe portion of the sole communicating the interior toe area of the footwear article with the air passages and a series of heel openings are provided in the heel portion of the sole communicating the interior heel area of the footwear article with the air passages whereby alternate compression and expansion of the resilient heel portion occurring during normal use of the footwear article alternately forces air out and into the cavity via the toe and heel openings to accomplish ventilization of the footwear article.

Application Number:
Publication Date:
Filing Date:
Primary Class:
International Classes:
A43B7/06; (IPC1-7): A43B7/06
Field of Search:
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US Patent References:
3475836AIR PUMPING INSERT FOR SHOES1969-11-04Brahm

Foreign References:
Primary Examiner:
Lawson, Patrick D.
What is claimed is

1. A sole for footwear having a bottom layer and a top layer extending over the entire area to be occupied by the sole of the foot, a heel composed of resilient material secured to the bottom face of said bottom layer and having means therein defining a central cavity defined by resiliently deformable walls and an opening in the top deformable wall, means defining longitudinal grooves disposed between said top and bottom layers extending from a toe portion of the sole to a heel portion thereof and communicating with said opening, and means defining through apertures both in a heel portion of said top layer communicating with said opening and in a toe portion of said top layer communicating with said longitudinal grooves, whereby alternate deformation and release of said deformable walls causes air to alternately pass out of and into said central cavity through said opening.

2. A sole as claimed in claim 1, in which an inner sole part is provided adjacent said top layer for blocking the through apertures.

3. Footwear having a sole as claimed in claim 1.

4. An article of footwear comprising: an upper; and a sole connected to said upper, said sole having a heel portion composed of resilient material and a toe portion, means defining passages extending interiorly of said sole from said heel portion to said toe portion, means defining heel openings in said sole communicating the interior heel area of said upper with the heel portion of said passages, means defining toe openings in said sole communicating the interior toe area of said upper with the toe portion of said passages, and means defining a cavity in said heel portion in communication with said heel openings and having sufficient size to render said heel portion compressible in response to pressure exerted thereon by the heel of the wearer during use of the footwear article; whereby said heel portion alternately undergoes compression and expansion during use of the footwear article to alternately force air from within said cavity out through said toe openings and draw air into said cavity through said heel openings to effectively ventilate the footwear article.

5. An article according to claim 4 wherein said sole comprises an outer sole, and an intermediate sole connected to said outer sole in opposed relationship therewith; and wherein said passages are located between said outer and intermediate soles; and wherein said toe and heel openings extend through said intermediate sole.

6. An article according to claim 1; including a detachable inner sole configured to detachably fit within said upper and having means thereon for effectively blocking said toe and heel openings when same is fitted within said upper.

7. An article according to claim 1; wherein said passages extend longitudinally through said sole; and including means defining at least one connecting passage extending interiorly of said sole in a direction substantially transverse to that said first-mentioned passages and providing communication therebetween in said toe portion.

8. An article according to claim 7; wherein all of said toe and heel openings communicate with one of said passages and connecting passages.


The invention relates to soles for footwear which can be worn in areas having either warm or cold climates.

It is known that the sole of an article of footwear plays an important part in the well-being and health of a foot, and even has an influence on the general fatigue of an individual wearing the footwear.

A number of studies have been made concerning the material and the shapes of soles, in order to produce a sole having the optimum comfort for the foot of a wearer of footwear to which the sole is fitted. Different materials have been proposed, for example, material such as leather exhibiting the property of allowing the foot to breath properly inside the footwear. Other materials have been proposed which have the property of thermally insulating the foot inside the footwear. Unfortunately, no single material exhibits both of these properties to an adequate degree for practical purposes.

It is difficult to produce a sole having the properties of allowing the foot to breath, which is required for footwear in hot climates, and having the property of thermal insulation, which is a prerequisite of footwear in cold climates, without having a complicated variety of constituent parts which consequently causes production costs to be high.

Soles for footwear are known which are formed from several successive layers of synthetic materials, and of materials having similar characteristics to those of leather in order to permit insulation and respiration of the foot.

Soles utilizing an air cushion to produce a perfect insulation are also known. Nevertheless, the results are often not satisfactory.

Footwear in which a blowing device for producing a current of air in the footwear, fitted in the hollow between the heel and the sole, are also known. Such footwear probably could put the foot at ease if commercialization was possible. In fact, this added blower device not only substantially increases the production cost of the footwear but, in addition, spoils the appearance of footwear and can irritate the foot during walking.

Certain sports footwear includes aeration openings arranged above the sole enabling the air to circulate into the interior or the footwear.

Again, the aeration is not efficient and, moreover, the footwear is subject to the incursion of water.


An object of the present invention is to provide a sole for footwear which permits a controlled ventilation inside the footwear, this ventilation preferably being directed towards the parts of the foot most sensitive to heat, and to a sole which has thermal insulation properties which insulate the foot from external cold conditions.

The ventilation is produced without making use of a supplementary device or insert as previously described and the insulation is produced without the need to change the structure of the sole, so that footwear thus equipped can be sold equally in any season without taking into account the inclemencies of the climate. The advantage is evident, as the manufacture at high production rates can be achieved, resulting in an attractive production price.

A further object of the present invention is to provide a sole having flexibility which softens shocks to the foot during walking and which decreases the amount of energy necessary for the displacement of the body. Another object of the present invention is to provide a sole which reduces wear on the heel of the sole.

Further objects of the invention will be understood when reading the description of the following preferred embodiment.

According to the present invention, a sole for footwear has a cavity defined by resiliently deformable walls and an opening in one wall communicating with the cavity whereby alternate deformation and release of the walls causes air in the cavity to pass out of and into the cavity through the opening.

Preferably, the cavity is arranged in the heel part of the sole.

In a preferred embodiment, an intermediate sole part is provided having with a plurality of through apertures, some arranged adjacent the heel part of the sole and some arranged adjacent the toe part of the sole, the opening interior of the footwear article communicating with the apertures. The through apertures may be positioned in intercommunicating grooves in the intermediate sole part.

An embodiment of the invention will now be described, by way of example, reference being made to the Figures of the accompanying drawings in which:

FIG. 1 is a side view of an article of footwear, the sole of which is shown in section;

FIG. 2 is a schematic underside plan view of the sole of FIG. 1 placed flat;

FIGS. 3 and 4 are perspective views of the footwear of FIG. 1.

As shown, an article of footwear in the form of a shoe 1 includes an upper and a sole 2 interconnected by any known means.

The sole 2 has a heel part 3 the walls of which are made of a resiliently deformable material and define a cavity 4. The cavity 4 may have a depth up to 20 mm and is of sufficient size to render the heel part compressible in response to pressure exerted thereon by the wearer during normal walking. However, the cavity 4 can be extended throughout the length of the sole 2 but, in such a case would be progressively reduced towards the toe of the footwear.

Between the upper and an outer or ground contacting sole part, there is provided an intermediate sole part 5, in which two passages or grooves 6 are formed which run longitudinally and interiorly of the sole 2. The grooves are interconnected at their ends adjacent the heel part 3 by a transversely extending passage or groove and have a depth and width which is no greater than 1 mm to 2 mm. Two groups of through apertures or openings 7, 8 are formed in the grooves 6, which apertures 7, 8 extend between the grooves and the opposite face of the intermediate sole 5. The transverse groove (see FIG. 2) also has through apertures 7.With the intermediate sole 5 adhering to the outer sole, the grooves 6 form closed channels which open out into the interior of the shoe 1, on one side at the height of the heel through the apertures 7, and on the other side, to the height of the metatarsus through the apertures 8 near the toe part of the sole 2. The outer sole has, at the height of the heel 3, a cut-out section which contributes to the formation of the cavity 4 made in the heel 3. This cut-out section is in general alignment with an opening in one of the walls defining cavity 4.

This arrangement ensures communication between an area 9 located above the heel inside the footwear cavity 4 of the said heel 3 and an area 10 located inside the shoe towards the toe of the shoe.

The sole material can comprise any type of material normally used as soles, for example, leather. The sole can be lined by another material having greater insulation properties in the case of highly perfected footwear.

The intermediate sole 5 can also be made of a material currently used in the trade, for example, leather. The intermediate soles can possibly be lined so that the foot rests on a more agreeable material than leather but, it would be necessary in such a case, to also perforate the lining. The grooves 6 are produced by known methods.

Although the material of the outer sole, in the above described embodiment, is not required to have any special properties other than those of insulation and flexibility, the heel 3 material, on the contrary, must be resiliently deformable. This material must enable the heel 3 to undergo a controlled deformation in order to endure the forces to which it is submitted without premature fatigue. Its consistency should be firm in such a way as to offer a certain resistance to pressure, the edges of the hollow space able to bend under the pressure of the force of the body. Furthermore, in submitting to the deforming effect, it should soften the shocks from steps, additionally, the pressure of the foot on the ground should be facilitated without inordinately inducing the ankles own rotation. On the resilient other hand, it is desirable that the energy freed by the sole in expanding back to its original shape helps the leg to lift itself up in order to make a step whereupon the step is thus made lighter. The cavity in the sole 2 because of its aforementioned features, is foreseen as much for footwear intended for use in hot countries as suitable for cold countries.

In order to comply with all the aforementioned requirements, by way of example, rubber is suggested as the material from which the sole 2 should be formed. Plastic materials and even leather are also suitable, but the heel 3 will be less efficient. The heel 3, of preference, is produced by moulding and affixed to the sole 2 by adhesives or vulcanizing. By way of variation, it is possible to produce the heel and the sole in only one piece obtained by moulding.

As far as the fitting of the intermediate sole 5 to the outer sole is concerned, various means of production are possible. Of preference recourse is made to the most known, namely, adhesives or vulcanizing according to the chosen material. The choice of the material presents no difficulty, is it is sufficient to make use of materials already currently used in the trade.

As shown in FIGS. 3 and 4, when the heel 3 presses on the ground (FIG. 3) the two upper surfaces 11 and the lower surface 12 of the cavity 4 come together.

In fact, the edges bend under the weight of the body. At the same time, the metatarsus which rests on the apertures 7 before uncovering these apertures and by leaving an area 13 free, enables the air ejected by the compression of the cavity 4 to escape from the apertures 8 into the interior of the shoe. The air escapes adjacent the toes in order to next find an outlet by the ankles. When the heel 3 is lifted to make a step (FIG. 4) the apertures 7 located near the heel 3 are uncovered, the lifted foot leaving a free area 14 enabling outside air to enter therein and to penetrate into the cavity 4 which again takes up its original shape. This transfer is again effected when the apertures 8 located adjacent the toe are blocked by the metatarsus.

In other words, when the resiliently deformable walls of cavity 4 are alternately deformed and released, air is alternately expelled from and drawn into the cavity 4 via the opening in one of the walls defining the cavity.

The process is repeated at each step and, the foot in this manner is dried by the air which circulates around it.

When the same footwear such as have been described hereto is to be worn as winter footwear, a light supplementary detachable inner sole is fitted inside on the intermediate sole 5, the said light inner sole blocking the apertures 7, 8. When this inner sole is removed, the footwear can be returned to its original state. Advantageously, the removable inner sole could be made from an insulating material.

Under these conditions, the air contained in the cavity 4 is insulated and minimizes losses of heat through the sole.

By way of variation, the footwear can be directly manufactured as winter footwear by providing a non-perforated intermediate sole 5.

Moreover, the grooves 6 can be directly produced in the outer sole.

The invention has been described with regard to one particular embodiment. However, certain modifications to form, particularly with regard to the number of grooves, the number of apertures, and the dimensions of the heel can be made without departing from the scope of the invention as defined by the claims.