1. Technical field
The present invention relates to a shoe, in particular a sports shoe, with a ventilation system.
2. The prior art
The technical development of shoes, in particular sports shoes has advanced considerably in recent years. Sports shoes nowadays comprise sophisticated cushioning systems which meet to a great extent the different requirements during a gait cycle and which selectively support the biomechanical processes during walking or running.
However, a problem which has not been solved until now is a sufficient ventilation of the interior of the shoe and thereby of the foot. The reason is that the foot has a particularly high density of perspiration pores releasing great amounts of humidity in particular during sports activities. This humidity must be quickly removed from the surface of the foot in order to avoid a humid foot climate, which is not only uncomfortable but which may also lead to foot diseases and to blisters.
The solution to this problem is impaired by the plastic materials which are commonly used in modem sports shoes. Plastic materials can be produced with very different mechanical properties and are ideal for providing the above mentioned improvements in the cushioning behavior of the shoe. However, the permeability to air and humidity of these materials is typically reduced compared to natural materials such as leather.
Therefore, there are approaches in the prior art to improve the ventilation of the interior of the shoe by various systems. For example, the applicant of the present invention has already disclosed in the DE 100 36 100 a multilayer sole construction having overlapping openings in different sole layers in order to allow a ventilation of the interior of the shoe from below.
With some shoes the specific field of use of the shoe can be advantageously used for ventilation. The US 4,640,027, for example, discloses a boot for motor cycling wherein the passing airflow is guided into the interior of the shoe via an opening arranged at the shaft of the boot. The US 6,196,556 discloses in a similar manner an inline roller skate having an opening at its front end between the shoe and the rolls, into which the airflow can enter via several holes from below to ventilate the foot sole.
In both constructions the high velocity of the shoe relative to its environment is used to guide the air into the interior of the shoe. However, if these constructions are transferred to ordinary shoes, a considerably reduced ventilation effect is noted. This corresponds to the general observation that the arrangement of openings in the shoe alone is not sufficient for an effective ventilation.
It is therefore the problem of the present invention to provide a shoe, in particular a sports shoe with a ventilation system providing a good ventilation of the interior of the shoe also in the absence of high velocities relative to the surrounding air in order to overcome the above mentioned disadvantages of the prior art.
3. Summary of the invention
According to a first aspect, the present invention relates to a shoe, in particular a sports shoe, with a ventilation system comprising an opening, at least one guiding surface extending over the opening, wherein the guiding surface is arranged such that it guides air into the opening of the ventilation system under a movement of the shoe through the air, in particular under a running movement of the shoe.
The invention is based on the realization that even the low relative velocities of 5 - 10 m/s between a shoe and the passing air for example during walking or running are sufficient to guide the air to the interior of the shoe, if the design of the opening of the ventilation system according to the invention is used. As a result, fresh air is permanently supplied to the foot so that the air around the foot does not become saturated with humidity. Thus, any humidity released from the surface of the foot can quickly evaporate.
In contrast to the arrangement of simple holes, the shoe is actively ventilated when the guiding surface directs the passing air into the opening and thereby into the ventilation system. In addition to the common passive ventilation based on thermal convection the arrangement of the guiding surface according to the first aspect of the present invention uses a flow effect even at low velocities due to the movement of the shoe, which increases in turn convection and evaporation.
Preferably, the guiding surface completely bridges the opening and is in one embodiment substantially vertically orientated with respect to the movement of the shoe. However, presently preferred is an inclined orientation of the guiding surface with respect to the longitudinal axis of the shoe. Particularly preferred is an arrangement, wherein the guiding surface is substantially parallel to the passing air during the phase of the greatest relative velocity of the shoe during a step cycle. Such an orientation is preferably obtained with an angle β of 0° to 60° between the longitudinal axis of the shoe and the guiding surface, more preferably between 0° and 40° and most preferably with approx. 40°.
Particularly preferred is a slight tilting of the outer edge of the guiding surface in forward direction. This has a particularly effective influence on the airflow passing along the surface of the shoe, which is deviated in a funnel-like manner into the opening of the ventilation system.
Preferably, a plurality of guiding surfaces extend over the opening of the ventilation system, wherein the plurality of guiding surfaces are substantially identically shaped and/or parallely with respect to each other. The plurality of guiding surfaces are preferably interconnected by at least one beam. Thus, a stable framework is created which is capable of permanently resisting the substantial mechanical loads within the shoe.
According to one embodiment, the opening of the ventilation system is preferably at least partly closed by a cover on both, the medial and the lateral sides, and the cover is preferably removable. Thus, the ventilation properties of the shoe can be quickly adapted according to the weather conditions, sporting activities being undertaken and the preferences of the wearer. Further, a partial cover of the guiding surfaces forms an effective air channel in the above discussed phase of the greatest relative velocity.
Preferably, the at least one opening is arranged in the midfoot area, wherein the ventilation system preferably comprises a lateral and a medial opening. In addition, at least one opening is preferably arranged in the sole region. The preferred distribution of the openings allows to ventilate a great part of the surface of the foot without impairing the flexibility in the forefoot region as well as the stability in the loaded heel region.
The ventilation system further comprises an outlet so that the air can leave the environment of the foot. This avoids a build-up of air pressure inside the ventilation system and assures a constant exchange of air in the interior of the shoe.
According to a further aspect, the present invention relates to a shoe, in particular a sports shoe, with a ventilation system comprising an inlet, and outlet and a ventilation channel extending along the lateral and/or the medial side of the shoe.
The arrangement of the ventilation channel along the medial or lateral side of the shoe facilitates the guidance of a continuous airflow along the foot which can be directed in suitable places to the interior of the shoe from the side or even from below. The ventilation channel on the side thereby enables the guidance of great volumes of passing air to those areas of the foot where the greatest amount of heat and humidity is produced.
The inlet is preferably arranged on the side of the instep and directed forwardly with an angle of inclination between 0° and 45° with respect to the longitudinal axis of the shoe. In this position the laminar airflow along the surface of the shoe can be effectively guided into the ventilation channel in a similar manner to the ventilation of the engine compartment of powerful motor vehicles. A streamlined covering element of the lacing (not shown) could increase the effectiveness of the system.
In a particularly preferred embodiment, several substantially parallel ventilation channels extend along the medial and the lateral sides of the shoe. Preferably, several inlet openings are arranged on the medial and/or the lateral side of the instep. This maximizes the above mentioned laminar airflows that can be used for ventilation.
Additional advantageous developments of the shoe according to the invention are the subject matter of further dependent claims.
4. Short description of the drawings
In the following detailed description, a presently preferred embodiment of the invention is described with reference to the drawings which show:
- Fig. 1:
- a top view of a preferred embodiment of the present invention;
- Fig. 2:
- a medial side view of the embodiment of Fig. 1;
- Fig. 3:
- a medial side view of the embodiment of Fig. 1 during the phase of the greatest relative velocity of the shoe with respect to the surrounding air;
- Fig. 4:
- a lateral side view of the embodiment of Figs. 1 and 2;
- Fig. 5:
- a bottom view of the preferred embodiment; and
- Fig. 6:
- an exploded representation to illustrate the assembly of the embodiment of Figs. 1 - 5.
5. Detailed description of the preferred embodiment
In the following, a preferred embodiment of the shoe according to the invention is described with reference to a sports shoe. However, it is to be noted that the present invention can also be used to improve the ventilation of other types of shoes.
Fig. 1 shows a top view of the presently preferred embodiment of a shoe 1 according to the invention. As can be seen, an opening 10 is arranged on the medial as well as on the lateral side of the shoe. A plurality of substantially parallel arranged flat ribs 11 bridge the opening 10. The angle α indicates a preferred slight tilting of the outer edge of each rib 11 to the front of the shoe. In the preferred embodiment as shown, the ribs 11 are arranged inside the opening 10. However, they can also be arranged above the opening 10.
On the lateral side of the shoe on the right of Fig. 1, the effect of the ribs 11 is explained. The arrows illustrate the direction of the airflow around the shoe. As in the case of every moving body, the air surrounding the shoe flows around the shoe 1during walking or running. If there are no turbulences, the streamlines are close to the surface of the shoe. As indicated by the arrows in Fig. 1, the flat ribs 11 serve as guiding surfaces deviating the passing air into the opening 10. Thus, fresh air is permanently directed into the interior of the shoe, even if the shoe only moves with a low velocity. The extent of the ventilation effect obtained thereby is determined by the size and angular position of the flat ribs 11. For example, ribs 11 having a greater surface area deviate greater amounts of air into the opening 10. However, they simultaneously increase the width of the shoe 1.
The ribs 11 may be substantially vertically oriented. However, in the preferred embodiment they are inclined by an angle β with respect to the longitudinal axis of the shoe. The angle β is selected such that a substantially parallel orientation of the ribs 11 is obtained with respect to the direction of motion and thereby to the passing air, when the foot is quickly brought forward after push-off during the phase of the greatest velocity relative to the surrounding air. This situation is schematically shown in Fig. 3 (cf. the arrows indicate the airflow into the opening 10 in a direction parallel to the ribs 11).
Due to this specific orientation the ribs 11 serve as an active guiding surface during phases of the step cycle with comparatively low relative velocities, whereas during the phase of the greatest relative velocity they are tilted parallel to the flowing air leading to a reduced resistance for the air entering the opening 10. The opening area is perpendicular to the direction of movement of the shoe during this phase. Depending on the type, the field of use and the design of the shoe the angle β between the longitudinal axis and the ribs 11 may vary. Preferred values are between 0° and 45°. Particularly preferred is an inclination of 40°.
As can be seen in the medial side view of a preferred embodiment in Fig. 2 the opening 10, which is bridged by the flat ribs 11, is bordered by a frame 13. This frame 13 comprises one or more transverse beams 14 for reinforcement which interconnect the parallel ribs 11 to a framework and thereby increase the stability of the arrangement.
Although not shown in the figures, it is conceivable to rotatably suspend the flat ribs 11 in the frame 13 to allow a modification of the angle α and thereby of the obtained ventilation effect. For example, each rib 11 can be suspended by means of two small pins (not shown) on its upper and lower side in the frame 13. If the transverse beam 14 is mounted to the ribs 11 independently of the frame 13, a simple forwardly or backwardly directed movement of the beam will simultaneously rotate all ribs 11 allowing a simple adaptation of the ventilation properties. Such a design is similar to the adaptation of the ventilation of the engine compartment of motor vehicles or the like, wherein substantial amounts of heat are generated due to the high power.
Fig. 4 shows the lateral side of the embodiment of Figs. 1 and 2. As can be seen, the lower part of the frame 13 and the ribs 11 are closed from the outside by a cover 20 . As a result, the ribs 11 form a sequence of ventilation channels 30 extending along the side of the shoe. The cover 20 may be made from a foil, a functional membrane and / or a breathable mesh material.
In a further embodiment (not shown) the inlet openings of these ventilation channels 30 are not open to the side but laterally arranged adjacent to the instep and substantially forwardly directed. In this embodiment, the arrangement of additional guiding surfaces is not necessary, since the substantially forwardly directed inlet openings can immediately focus the airflow into the ventilation channels 30.
The cover 20 may be removably mounted to the shoe 1, for example using a hook and loop fastener such as sold under the name Velcro®. As a result, the ventilation properties of the shoe 1 can be very easily modified. In addition, it is conceivable to provide an alternative or additional cover which completely closes the opening 10 to seal the shoe 1 during the cold season or in bad weather. Although in the discussed figures the cover 20 is only shown on the lateral side of the shoe 1, it is to be understood that the cover may additionally or alternatively also be arranged on the medial side of the shoe.
There are several different ways in which the airflow can be further guided to the interior of the shoe. In the most simple case, the opening 10 already leads directly to the interior of the shoe. This ensures a very effective ventilation of a large surface area of the interior of the shoe. Alternatively, however, the above mentioned ventilation channels 30 can be used to selectively direct the airflow onto certain parts of the sole. It is for example possible to guide the airflow onto the lower side of the foot via suitable openings in the midsole or insole. However, the ventilation channels extending on the lateral and/or on the medial side can also be used to supply the foot with fresh air from the side. In contrast to a single channel extending at the end of the shoe, the ventilation channels on the side allow an easier access to great parts of the foot without a complex additional channel system inside the sole.
If an opening having a large surface area is used, a breathable membrane can be arranged, either in front, within or behind the frame 13 to avoid the unintended penetration of exterior humidity into the interior of the shoe. However, it has to be taken into account that even a breathable membrane will deteriorate the ventilation properties since it presents an additional resistance for the airflow to the foot. Thus, the arrangement of a membrane will depend on the field of use of the respective shoe.
The particularly preferred ventilation of the interior of the shoe is obtained if the airflow is not only guided into the shoe but also out of the shoe. This facilitates the constant exchange of the air surrounding the foot so that the air does not become saturated with humidity. To this end, it is advantageous, if an outlet is provided at least somewhere in the shoe. Fig. 5 shows a bottom view of the preferred embodiment of the shoe. As can be seen several openings 40 are provided between the sole regions of the heel 2 and forefoot 3 allowing the air entering the channels 30 to emerge. As a result, a continuous airflow is created along the midfoot part.
However, this is only one possibility. Alternatively, other outlet openings (not shown) may be arranged in different positions of the shoe, for example in the heel. In this case, also the openings 40 primarily serve as inlet openings of the ventilation system.
Fig. 6 schematically shows the preferred manufacture of the described embodiment:
To this end, at first the ribs 11 are produced together with the surrounding frame 13, for example by an integral manufacture by injection molding. Other manufacturing techniques such as gluing or welding, however, are also conceivable. Preferably, plastic materials such as TPE, TPU or RPU are used which are on the one hand sufficiently stable and on the other hand sufficiently flexible so that they can elastically react to the mechanical loads arising in the shoe.
Simultaneously, additional functions for the shoe can be integrated into the frames 13. Fig. 6 shows for example holes 15 for receiving laces or similar fastening systems of the shoe.
Also the above discussed openings 40 on the lower side of the shoe 1 are preferably pre-manufactured as framed components 41 which are subsequently integrated into the sole of the shoe (cf. Fig. 5). As in the case of the frames 13, the framed components 41 are connected to the sole of the shoe by gluing, welding or any other technique, which is suitable for a permanent interconnection of plastic materials. In the case of the frames 41, it is also possible to insert the finished elements into a mould and to vulcanize the sole around the elements.
Additionally, Fig. 5 schematically shows a torsion bar 50 between the heel part and the forefoot part of the sole. The torsion bar determines the torsional rigidity between the forefoot part 2 and the heel part 2 and thereby controls a rotation of the two sole components with respect to each other. The more elastic the materials used for the frames 13 and 41, the greater the influence of the torsion bar 50.
In the described preferred embodiment, the ventilation openings 10, 40 are exclusively arranged in the midfoot part. This is preferred, since there are lower mechanical loads in this part of the sole than in the heel and forefoot parts. A premature wear due to abrasion on the ground or the like is thereby avoided. However, alternatively or additionally, it is also possible to arrange one or more of the described openings in the forefoot part or the heel part of the shoe.
Shoe (1), in particular a sports shoe, comprising:
a. a ventilation system with an opening (10);
b. at least one guiding surface (11) extending over the opening (10);
c. wherein the guiding surface (11) is arranged such that it directs air into the opening (10) of the ventilation system under a movement of the shoe (1) through the air.
2. Shoe (1) according to claim 1, wherein the guiding surface (11) completely bridges the opening (10).
3. Shoe (1) according to claim 1 or 2, wherein the guiding surface (11) is substantially perpendicularly oriented with respect to the direction of movement of the shoe (1).
4. Shoe (1) according to claim 1 or 2, wherein the guiding surface (11) is inclined with respect to the longitudinal axis of the shoe (1) (β < 90°).
5. Shoe (1) according to claim 4, wherein the guiding surface (11) is oriented such that it is substantially parallel with respect to the passing air during the phase of a step cycle with the greatest relative velocity.
6. Shoe (1) according to claim 5, wherein the guiding surface (11) is oriented with an angle β between 0° and 60°, preferably between 0° and 45° and most preferably approx. 40° with respect to the longitudinal axis of the shoe.
7. Shoe (1) according to any of the claims 1 to 6, wherein the outer edge of the guiding surface (11) is slightly tilted in a forward direction.
8. Shoe (1) according to one of the claims 1 to 7, wherein a plurality of guiding surfaces (11) extend over the opening (10) of the ventilation system.
9. Shoe (1) according to claim 8, wherein the plurality of guiding surfaces (11) are substantially identically shaped and/or parallel with respect to each other.
10. Shoe (1) according to claim 9, wherein the plurality of guiding surfaces (11) are interconnected by at least one beam (14).
11. Shoe (1) according to one of the claims 1 to 10, wherein the opening (10) of the ventilation system is at least partially closed by a cover (20).
12. Shoe (1) according to claim 11, wherein the cover (20) is removable.
13. Shoe (1) according to one of the claims 1 to 12, wherein the opening (10) further comprises a membrane.
14. Shoe (1) according to one of the claims 1 to 13, wherein the opening (10) is arranged in the midfoot region.
15. Shoe (1) according to one of the claims 1 to 14, wherein the ventilation system comprises a lateral and a medial opening. (10).
16. Shoe (1) according to one of the claims 1 to 15, wherein the ventilation system further comprises at least one opening (40) in the sole region.
17. Shoe (1) according to one of the claims 1 to 16, wherein the ventilation system further comprises an outlet (40).
Shoe (1), in particular a sports shoe, with a ventilation system comprising:
a. an inlet (10);
b. an outlet (40);
c. a ventilation channel (30) extending along the side of the shoe (1).
19. Shoe (1) according to claim 18, wherein the inlet is laterally arranged next to the instep and forwardly directed with an angle of inclination between 0° and 45° with respect to the longitudinal axis of the shoe.
20. Shoe (1) according to claim 18 or 19, wherein the outlet (40) of the ventilation system is arranged in the sole region of the shoe (1).
21. Shoe (1) according to claim 20, wherein the outlet (40) is arranged in the central sole region.
22. Shoe (1) according to claim 21, wherein the ventilation channel (30) comprises at least one connection to the interior of the shoe.
23. Shoe (1) according to claim 21 or 22, wherein the ventilation system comprises a lateral and a medial ventilation channel (30).
24. Shoe (1) according to claim 23, wherein several substantially parallel ventilation channels (30) extend along the medial and/or the lateral side of the shoe (1).