Patent Publication Number: US-2020281324-A1

Title: Method for producing a shoe with an air pump device, comprising a bellows which is formed in a midsole

Description:
The invention relates to a method for producing a shoe with an air pump device arranged in the heel region comprising at least one bellows, into which at least one air intake duct opens and to which at least one air-guiding duct which opens into the interior of the shoe is connected, an upper having an upper material section and a sole section having a lower face, a midsole having an upper face and a lower face, and an outsole having an upper face being provided, wherein the midsole comprises a recess for forming at least one cavity for the at least one bellows of the air pump device, wherein the upper, the midsole, and the outsole being interconnected by first either the lower face of the sole section of the upper being connected to the upper face of the midsole and then the combination of the upper and midsole being connected to the outsole or first by the lower face of the midsole being connected to the upper face of the outsole and then the combination of the midsole and outsole being connected to the upper. 
     From the earlier applications EP 2 218 348 A1, WO 2012/126489 A1 and EP 3 078 288 A1, various designs of shoes are known which comprise an air pump device comprising at least one bellows arranged in the heel region of the shoe and in which an air intake duct opens into the bellows and at least one air duct opening into the interior of the shoe is connected to the bellows. In an embodiment described in EP 2 218 348 A1, a midsole made of a compressible material is arranged between a hard outsole and a harder sock, it being possible for a cavity for receiving a bellows of the air pump device to be embedded in the midsole in the heel region. WO 2012/126489 A1 discloses a shoe comprising an air pump device in a sole construction, in which the sole construction comprises a lower outsole part and an upper sole part, the bellows of the air pump device substantially being formed in the upper sole part in a cavity that is delimited at the top and sides by the upper sole part and at the bottom by the outsole part. The sole construction described is intended to be produced from a resilient material by plastics injection molding, for example. 
     EP 3 078 288 A1 discloses a method for producing a shoe comprising an air pump device, in which a pre-assembled upper having a perforated insole, various components of an air pump device (namely bellows, air intake duct and air ducts comprising one-way valves) and a one-piece sole construction are provided and the upper is then connected to the one-piece sole construction such that (for example by bonding) the components of the air pump device are positioned in cut-outs in the one-piece sole construction between this sole construction and the insole. In one described embodiment, the one-piece sole construction is intended to be injection molded onto the lower face of the insole, to which the components of the air pump device have previously been attached. A drawback here is the manufacturing complexity, in particular the complexity required in order to avoid compression of the cavities receiving the components of the air pump device on account of the injection pressure. 
     Proceeding from this prior art, the problem addressed by the invention is to provide a cost-effective production method which, on one hand, utilizes the advantages of connecting the sole construction to the upper by means of injection molding technology, but on the other hand enables the air pump device to be inserted without considerable additional complexity. 
     This problem is solved according to the invention by a method having the features of claim  1 . In this method for producing a shoe comprising an air pump device arranged in the heel region comprising at least one bellows, into which at least one air intake duct opens and to which at least one air-guiding duct which opens into the interior of the shoe is connected, an upper having an upper material section and a sole section having a lower face, a midsole having an upper face and a lower face, and an outsole having an upper face are provided, wherein
         either the lower face of the midsole has a surface having a first surface profile and at least one recess adjacent to this surface for forming at least one cavity for the at least one bellows of the air pump device, and the upper face of the outsole has a surface having a second surface profile which is complementary to the first surface profile at least in part such that the complementary surface regions of the second surface profile of the outsole and the first surface profile of the midsole surround the at least one recess on all sides,   or the upper face of the midsole has a surface having a first surface profile and at least one recess adjacent to this surface for forming at least one cavity for the at least one bellows of the air pump device, and the lower face of the sole section of the upper has a surface having a second surface profile which is complementary to the first surface profile at least in part such that the complementary surface regions of the second surface profile of the sole section and the first surface profile of the midsole surround the at least one recess on all sides, wherein the horizontal extension of the upper face of the outsole and the horizontal extension of the sole section of the upper are greater than the horizontal extension of the midsole such that the midsole can be positioned so as to be centered between the outsole and the upper such that the outsole and the upper protrude beyond the outer edge of the midsole on all sides. To connect the upper, the midsole and the outsole, first either the midsole is applied in a centered manner to the lower face of the sole section of the upper and the upper having the applied midsole is pressed onto the upper face of the outsole, the outsole previously being provided in a base element of an injection mold, or the midsole is applied in a centered manner to the upper face of the outsole and the outsole having the applied midsole is applied to the lower face of the upper. Here, the complementary surface regions of the first surface profile of the upper face or the lower face of the midsole and the second surface profile of the lower face of the sole section or the upper face of the outsole are adhered such that the at least one cavity of the at least one recess is completely enclosed. Then, the upper, the midsole and the outsole are enclosed by an injection mold and the surface regions of the upper face of the outsole not covered by the midsole, the lateral outer surfaces of the midsole and the lower face and adjacent lateral surface regions of the upper are overmolded with an edge sole region plastic in order to interconnect the outsole, the midsole and the upper by forming an edge sole region.       

     A “bellows” is to be understood here to mean an air-admitting, resiliently compressible cavity enclosed by walls, which, when compressed, ejects air via a coupled air-guiding duct and which, when subsequently expanded, suctions in air via an air intake duct. The walls surrounding the cavity of the bellows could be formed by the walls of a plastics bubble inserted in the recess, but are preferably formed by the walls of the recess in the midsole delimiting the cavity and either the lower face of the sole section of the upper covering the recess or the upper face of the outsole itself covering the recess. The “sole section” of the upper represents the part of the upper facing the outsole, which preferably comprises an insole or consists of the insole. The terms upper face and lower face refer to the position of the sides described as such in the normal wearing position of the shoe. If it is said that the first surface profile and the second surface profile are complementary at least “in part,” this means that the two surface profiles are complementary at least in portions of their total surface arranged opposite one another, such that they lie against one another over the entire surface in these portions. If, based on this understanding, it is further specified that the complementary surface regions “surround the at least one recess on all sides,” this means that the portions lying against one another surround this recess or recesses such that the cavity of the recess or recesses is completely enclosed by the walls of the components of the shoe having the complementary surface regions (either midsole and outsole or midsole and sole section of the upper). One exception to this is the openings in the bellows to the air intake duct and air-guiding duct. 
     The method according to the invention, in which the shoe is produced from three prefabricated sole components which are overmolded for connection to a fourth component, has several advantages. The formation of the bellows cavity in the air pump device by means of a recess in a prefabricated midsole that is open on one side simplifies the production of the air pump device. Closing the cavity formed by the recess by means of a second sole component adhered to complementary surfaces before the overmolding enables the cavity in the air pump device to be protected in an easy-to-produce manner against undesired compression by the injection pressure during the overmolding and against penetration of the plastics material, which is still liquid. The method according to the invention provides a simple design of the components of the air pump device and prefabrication and pre-assembly of these components in the sole components. It also allows suitable sole materials to be selected for the sole components depending on their respective functions. 
     The injection pressure in step b) is preferably selected depending on the material of the midsole such that the at least one cavity of the at least one recess is not compressed or only slightly compressed. 
     In a preferred embodiment, in step a1-1) or in step a2-2), the upper is positioned on a last such that the lower face of the sole section points upwards. This simplifies an operator&#39;s control of the correct positioning of the midsole on the lower face of the sole section. 
     In a preferred development of the method, in step a1-1) or in step a2-1), the midsole is applied in a centered manner by it being positioned using markings or projections on the lower face of the sole section of the upper or on the upper face of the outsole. This serves to facilitate the correct positioning of the midsole. 
     A preferred variant of the method is characterized in that an upper is provided which has a first air intake duct extending from the sole section along its upper material section comprising an air intake opening spaced apart from the sole section and a first connecting element arranged on the sole section; a midsole is provided which has, on its upper face, a second connecting element connected to a second air intake duct of the air pump device; and steps a1-1) and a1-2) are carried out, wherein, in step a1-1), the first and the second connecting element are interconnected in order to connect the second air intake duct of the midsole to the first air intake duct of the upper. This separation of the components of the air intake duct and their pre-assembly on the upper and the midsole allows for simplified handling and more rapid assembly when connecting the components of the shoe. In this case, an upper is preferably provided which has a first air intake duct extending along its heel region. 
     A first embodiment of the method is characterized in that the upper face of the midsole comprises the surface having the first surface profile and the lower face of the sole section of the upper comprises the surface having the second surface profile, such that the complementary surface regions of the first surface profile of the upper face of the midsole and the second surface profile of the lower face of the sole section are adhered in step a1-1). In this embodiment, the at least one recess in the midsole is thus open towards the sole section of the upper, i.e. open on the upper face of the midsole. 
     In this first embodiment of the method, the sole section of the upper may preferably comprise an insole which is reinforced in the heel region above the at least one recess containing the at least one bellows of the air pump device and is designed as a rigid pressure plate which covers the at least one recess. This improves the compression of the cavity formed by the recess. 
     A second embodiment of the method is characterized in that the lower face of the midsole comprises the surface having the first surface profile and the upper face of the outsole comprises the surface having the second surface profile, such that the complementary surface regions of the first surface profile of the lower face of the midsole and the second surface profile of the upper face of the outsole are adhered in step a1-2) when the upper having the applied midsole is pressed onto the upper face of the outsole. In this embodiment, the at least one recess in the midsole is thus open towards the outsole, i.e. open on the lower face of the midsole. 
     In this second embodiment of the method, in step a1-1), the midsole may be adhered to the lower face of the sole section of the upper. Since, in this embodiment, the recess is open towards the outsole, when adhering the midsole to the lower face of the sole section of the upper, it is not important that the entire surface is adhered or that the surfaces adhered to one another have complementary profiles. This adhesion only serves to fix the midsole to the upper before overmolding. However, it is important here to ensure that the midsole is correctly positioned on the lower face of the sole section of the upper, so that, in step a1-2), the midsole fastened to the upper can then be correctly positioned on the outsole with the at least one downwardly open recess such that the complementary surface regions of the second surface profile of the outsole and the first surface profile of the midsole lie on one another. 
     The outsole is preferably provided in the base element of the injection mold by the outsole being produced in the base element by injection molding or casting. Part of the same device can thus be used in prefabricating the outsole. 
     In a preferred embodiment of the method, an outsole is provided which projects beyond the outer edge of the midsole on all sides such that the distance between the outer edge of the outsole and the outer edge of the midsole is between 5% and 20% of the length of the shoe. This range is optimal when contradicting requirements are to be met, namely both the requirement for a maximum horizontal expansion of the recess and thus the midsole, which allows for a maximum pump volume, and the requirement for the widest possible edge sole region to achieve a stable and permanent connection between the outsole and the upper. 
     A preferred development of the method is characterized in that a midsole is provided which consists of a plastics foam having a Shore A hardness of between 40 and 60 Shore. It has been shown that, when adhering to this hardness range, sufficient compressibility can be achieved both to obtain the most complete possible compression of the pump volume each time the user takes a step, and to obtain sufficient dimensional stability when the injection pressure is applied during the overmolding with the edge sole region plastic. 
     In a preferred embodiment, a midsole is provided comprising a recess arranged in the heel region for receiving a bellows of the air pump device, wherein the recess extends horizontally laterally and extends, at the back of the shoe, by a distance of approximately 1-5% of the length of the shoe from the edge of the midsole, wherein the bellows is formed by the recess that is covered by the lower face of the sole section or the upper face of the outsole and wherein a section of the at least one air intake duct and a section of the at least one air-guiding duct opening into the interior of the shoe are formed in the midsole. In this preferred embodiment, a maximum pump volume is achieved with sufficient resilience when pressure is relieved by lifting up the shoe after each step is taken. 
     Advantageous and/or preferred embodiments of the invention are found in the dependent claims. 
    
    
     
       The invention is explained in greater detail in the following on the basis of preferred embodiments shown in the drawings, in which: 
         FIG. 1  is a side view of the upper, midsole and outsole components of a shoe to be produced according to a first preferred embodiment of the method according to the invention; 
         FIG. 2  is a view of the midsole according to  FIG. 1 , in which the inner boundary lines which are not visible from the outside are made visible; 
         FIG. 3A to 3E  are side views of the components and the shoe according to  FIG. 1  in the various phases of production according to the first preferred method; 
         FIG. 4A  is a longitudinal sectional view and  FIG. 4B  is a cross-sectional view of a shoe produced according to the first preferred method shown in  FIG. 3A to 3E ; 
         FIG. 5  shows a side view of the upper, midsole and outsole components in the production phase after the midsole and outsole have been connected and before the midsole has been connected to the upper of a shoe produced according to an alternative variant of the first preferred method; 
         FIG. 6  is a side view of the upper, midsole and outsole components of a shoe to be produced according to a second preferred embodiment of the method according to the invention; 
         FIG. 7  is a view of the midsole according to  FIG. 6 , in which the inner boundary lines which are not visible from the outside are made visible; 
         FIG. 8A to 8E  are side views of the components and the shoe according to  FIG. 6  in the various phases of production according to the second preferred method; 
         FIG. 9A  is a longitudinal sectional view and  FIG. 9B  is a cross-sectional view of a shoe produced according to the second preferred method shown in  FIG. 8A to 8E ; 
         FIG. 10  shows a side view of the upper, midsole and outsole components in the production phase after the midsole and outsole have been connected and before the midsole has been connected to the upper of a shoe produced according to an alternative variant of the second preferred method; 
         FIG. 11A to 11F  are perspective views of the components of a shoe in the various phases of its production according to a third embodiment of the method according to the invention; and 
         FIG. 12  is a view from below of the midsole as used in the production method shown in  FIG. 11A to 11F . 
     
    
    
     A first embodiment of the method according to the invention for producing a shoe comprising an air pump device arranged in the heel region is to be described with reference to  FIGS. 1 to 4B . 
       FIG. 1  is a schematic side view of three basic components from which a shoe  1  is manufactured, namely an upper  2 , a midsole  3  and an outsole  4 . 
     The upper  2  comprises an upper material section  21  and a sole section  22 . The sole section  22  is to be understood here to mean the part of the upper which faces the ground and to which the sole construction described below is attached. The upper material section  21  is then the remaining part of the upper  2 . The sole section  22  usually comprises an insole and can also include further sole layers, for example soles inserted in the interior. In some embodiments, a separate insole can also be omitted and, for example, the leather of the upper can be guided around the foot from the upper material section downwards, as is the case with a moccasin, for example. 
     The midsole  3  is preferably produced in one piece from a compressible plastics material and contains, on its lower face  32 , a recess  36  which can be seen in a separate view of the midsole  3  in  FIG. 2 , in which the inner edges which are not visible from the outside are made visible. The midsole  3  shown in  FIGS. 1 and 2  also contains air-guiding ducts  38  which lead from the recess  36  to openings  33  on the upper face  31  of the midsole  3 . These air-guiding ducts  38  are connected to the cavity of the recess  36  via a one-way valve  37  such that when the cavity is compressed, the air contained therein can only escape through the one-way valve  37  in the direction of the air-guiding ducts  38 . Furthermore, the midsole  3  contains an air intake duct which is adjacent to the recess  36  at the rear of the shoe and which is likewise connected to the cavity of the recess  36  via a one-way valve  35 . This one-way valve  35  is designed such that it only lets the air through in the direction into the cavity of the recess  36 . The other end of the air intake duct comprises a connecting element  34 . 
     The sole section  22  (not shown in detail here) contains openings in the forefoot region which extend from its lower face as far as the interior of the shoe  1  and are arranged such that they are aligned with the openings  33  on the upper face  31  of the midsole  3 . Air which is pressed from the recess  36  into the air-guiding ducts  38  and then through the openings  33  thereof via the one-way valve  37  thus enters the interior of the shoe  1  through the openings in the sole section  22  of the upper. The upper also contains an air intake duct  24  comprising a connecting element  25  which is connected to the connecting element  34  of the air intake duct of the midsole  3  when the midsole  3  is attached to the upper  2 . At its upper end, the air intake duct  24  contains an air intake opening (not shown in detail here), which is preferably covered with a grid or a coarse-mesh fabric. The air intake duct  24 , on the back of the upper  2 , may also be designed (for example in a meandering shape) such that the air is deflected into its flow direction when it is suctioned in before it is guided downwards into the midsole. This deflection of the suctioned-in air flow can be used to separate water droplets and/or dirt particles contained in the air. The air intake duct  24  can also comprise a plurality of air intake ducts that are guided in parallel. In the embodiment shown in  FIG. 1 , the air intake duct  24  is formed on the back of the upper  2 . In alternative embodiments, it can also be formed on the inside or outside of the upper  2 . 
     A third shoe component shown in  FIG. 1  is the outsole  4 , which, on its upper face  41 , has an indentation, shown here by the edge  42 , into which the midsole  3  can be fitted. Here, the indentation makes it easier to position the midsole  3  relative to the outsole  4 . The material of the outsole  4  is preferably also a plastics or rubber material which is adapted to the requirements of an outsole  4 , in particular has high abrasion resistance. 
       FIG. 3A to 3E  show a first preferred embodiment of a method for producing the shoe  1  from the three shoe components, the upper  2 , midsole  3  and outsole  4 . In the preferred procedure according to  FIG. 3A , the upper  2  is positioned on a last (not shown here) such that its lower face, i.e. the sole section  22 , points upwards. Then the midsole  3  is placed from above onto the sole section  22  of the upper  2  and positioned in the process, the connecting elements  34  and  25  of the air intake duct being interconnected. The result is shown in  FIG. 3B . The lower face  32  of the midsole  3  points upwards here, such that, here, both the recess  36  and recesses of the air-guiding ducts  38  can be seen. The upper face  31  of the midsole  3  is preferably adhered to the sole section  22 . A full-surface adhesive connection is not necessary here; during adhesion, it is merely necessary both to ensure correct positioning of the midsole and to keep the connecting ducts between the openings  33  and the interior of the shoe  1  free. Either before the midsole is attached to the upper  2  or thereafter, the outsole  4  is placed, in the orientation shown in  FIG. 3B , into a base element (not shown here) of an injection mold, in which the outsole  4  is supported on its lower face over the entire surface thereof. 
     As can be seen in  FIG. 3C , the upper  2  having the midsole  3  attached thereto is rotated such that the lower face  32  of the midsole  3  faces the upper face  41  of the outsole  4 . The upper  2  having the midsole  3  is then moved downwards such that the midsole  3  is positioned in the indentation by means of the edge  42  and is pressed against the upper face  41  of the outsole  4 . The upper face  41  of the outsole  4  closes the recess  36  and the recesses in the air-guiding ducts  38 . For this purpose, at least the region of the surface of the lower face  32  of the midsole  3 , which surrounds the recess  36  and the recesses of the air-guiding ducts  38 , is complementary to the opposite surface of the upper face  41  of the outsole  4 , such that the cavity of the recess  36  and the cavities of the recesses of the air-guiding ducts  38  are sealed on all sides when the lower face  32  of the midsole  3  is pressed onto the upper face  41  of the outsole  4 . Before the lower face  32  of the midsole  3  is pressed onto the upper face  41  of the outsole  4 , the lower face  32  and/or the upper face  41  is coated with adhesive within the indentation. The adhesive bond between the lower face  32  of the midsole  3  and the upper face  41  of the outsole  4  completely surrounds the recess  36  and the recesses of the air-guiding ducts  38 , such that no gap remains between the midsole  3  and the outsole  4  which connects the recess  36  or the air-guiding ducts  38  to the environment. 
     The result after connecting the midsole  3  to the outsole  4  is shown in  FIG. 3D . Both the outer edge of the outsole  4  and the sole section of the upper  2  protrude beyond the outer edge of the midsole  3  such that the distance between the outer edge of the outsole and the outer edge of the midsole is between approximately 5% and 20% of the length of the shoe, for example approximately 10 to 20 mm. The arrangement shown in  FIG. 3D  is then enclosed by an injection mold and the surface regions of the upper face  41  of the outsole  4  that are not covered by the midsole  3 , the lateral outer surfaces of the midsole  3  and the surfaces of the sole region  22  that are not covered by the midsole  3  and adjacent lateral surface regions of the upper  2  are overmolded with an edge sole region plastic such that the outsole  4 , the midsole  3  and the upper  2  are firmly interconnected. The result is shown in  FIG. 3E . 
       FIGS. 4A and 4B  are schematic sectional views through the shoe  1  produced in the manner described above.  FIG. 4A  is a longitudinal sectional view which extends approximately centrally through the shoe. It shows the upper  2  having the upper material section  21  and the sole section  22  and the midsole  3  having the downwardly open recess  36 , the downwardly open recesses for the air-guiding ducts  38 , the openings  33 , the one-way valve  35  connecting the recess  36  to the air-guiding ducts  38 , and the air intake duct that comprises the connecting element  34  and is also connected to the recess  36  via a one-way valve  37 . The intake duct  24  together with its connecting element  25 , which are part of the upper  2 , are also visible. At the front and the back of the shoe  1 , parts of the edge sole region  5 , which connects the outsole  4  to the midsole  3  and the upper  2 , are visible in horizontal hatching.  FIG. 4B  is a sectional view through the heel region of the shoe  1  transversely to the direction of movement, the midsole  3  having the recess  36 , which is closed by the outsole  4 , the upper  2  having the upper material section  21  and the sole section  22 , and the edge sole region  5  also being shown here. 
     With reference to  FIG. 4A , the operating principle of the air pump device, which is known as such, will be briefly discussed. The downwardly open recess  36  in the midsole  3 , which is closed at the bottom by the outsole  4 , forms a cavity in the compressible midsole  3 . If the weight of the wearer of the shoe  1  presses on the heel region while walking, the cavity of the recess  36  is compressed by the midsole  3  being pressed together. The air contained in the cavity of the recess  36  is pressed through the one-way valve  35  while the one-way valve  37  closes. The air pressed through the one-way valve  35  passes into the interior of the shoe  1  in its toe or ball region via the air-guiding ducts  38  through the openings  33  and the corresponding openings in the sole section  22 . When the wearer of the shoe  1  then relieves the pressure of the foot and lifts the shoe  1  off the ground, the resilient restoring forces of the material of the compressed midsole  3  and the material of the compressed edge sole region  5  cause the cavity of the recess  36  to expand. Owing to the resulting negative pressure in the cavity of the recess  36 , the one-way valve  35  closes while the one-way valve  37  opens. Fresh air is thereby suctioned in via the air intake duct  24  from an intake opening (not shown in  FIG. 4A ) at the upper end of the air intake duct  24  and is conducted into the cavity of the recess  36 . When the wearer of the shoe  1  takes the next step, in which the wearer of the shoe  1  loads the heel again, the described process begins again. In each step, fresh air is suctioned in and then pumped into the interior of the shoe. 
     The plastics material of the edge sole region  5  is selected such that it adheres well to the surfaces of the upper  2 , the midsole  3  and the upper face of the outsole  4 . Furthermore, the edge sole region plastic has good compressibility in the hardened state, the compressibility being selected in conjunction with the compressibility of the midsole  3  such that when the wearer of the shoe  1  takes normal steps during the walking process, the cavity of the recess  36  is compressed as completely as possible. In addition, the plastics material of the edge sole region  5  is selected such that the resilience is sufficient to restore the shape of the midsole  3  as completely as possible, i.e. to expand the cavity of the recess  36  as completely as possible, within the short period of pressure relief of the foot during a step. 
       FIG. 5  shows a phase of the production of a shoe according to a modification of the production method shown in  FIG. 3A to 3E . It can be seen in  FIG. 5  that a midsole  3  that is already applied to the upper face of the outsole  4  is arranged above an upper  2 , the lower face of the sole section  22  of the upper  2  pointing upwards. In this embodiment of the method according to the invention, first the outsole  4  is provided in a mold, then the midsole  3  is adhered to the upper face  41  of the outsole  4  by its recess  36  which is open towards the outsole, such that the cavity of the recess  36  is enclosed on all sides. This combination of outsole  4  and midsole  3  is then attached to the lower face of the sole section  22 , an arrangement preferably being selected in which, as shown in  FIG. 5 , the upper  2  clamped to a last points upwards with its lower face, in order to facilitate the application of the combination of midsole  3  and outsole  4  to the upper  2 . While fastening this combination of midsole  3  and outsole  4  to the upper  2 , a connection is also made between the connecting element  34  and the connecting element  25  of the air intake duct. 
     An alternative embodiment of the method according to the invention for producing a shoe comprising an air pump device arranged in the heel region is to be described with reference to  FIGS. 6 to 9B . In this embodiment, a midsole  3 ′ is used in which the recess  36 ′ is arranged on the upper face of the midsole  3 ′ and is thus open towards the sole section  22  of the upper  2 . 
       FIG. 6  is a schematic side view of the three shoe components upper  2 , midsole  3 ′ and outsole  4  that are to be connected.  FIG. 7  is a view of the midsole  3 ′ according to  FIG. 6 , in which the inner edges and boundary lines not visible from the outside are made visible. The views in  FIGS. 6 and 7  correspond to the views in  FIGS. 1 and 2  of the first-mentioned, preferred embodiment of the method according to the invention, the same elements being provided with the same reference signs. With these same elements, reference can be made to the description of  FIGS. 1 and 2 . Differences arise in particular on account of the differing design of the midsole  3 ′. This midsole  3 ′ has a recess  36 ′ adjacent to the upper face  31 ′ for receiving a bellows of the air pump device. This bellows of the air pump device is preferably not a separate component, but rather is formed by the cavity of the recess  36 ′ itself. In a less preferred embodiment, a separate component, in particular a plastics bubble enclosing a cavity, can also be introduced into the recess  36 ′ as a bellows. Further recesses adjacent to the upper face  31 ′ of the midsole  3 ′ form air-guiding ducts  38 ′. The sole section  22  of the upper  2  in turn has openings which connect the interior of the shoe  1  to the air-guiding ducts  38 ′ after the midsole  3 ′ has been attached to the lower face of the upper  2 . 
     Individual phases of the production method are again shown in  FIG. 8A to 8E . As shown in  FIG. 8A , the outsole  4  is provided, preferably in a base element (not shown here) of an injection mold. Furthermore, the upper  2  is provided and arranged on a last (not shown here) such that the sole section  22  thereof points upwards. As shown in  FIGS. 8A and 8B , the midsole  3 ′ is first positioned on and adhered to the sole section  22  of the upper  2 . The upper face  31 ′ of the midsole  3 ′ has a surface having a first surface profile and the recess  36 ′ adjacent to this surface for receiving the at least one bellows of the air pump device as well as recesses for receiving the air-guiding ducts  38 ′. The lower face of the sole section  22  of the upper  2  has a surface having a second surface profile which is complementary to the first surface profile at least in part such that the complementary surface regions of the second surface profile of the sole section  22  and the first surface profile of the midsole  3 ′ surround the at least one recess  36 ′ and the recesses of the air-guiding ducts  38 ′ on all sides, such that the recesses are closed on all sides after adhering the midsole  3 ′ to the sole section  22  of the upper  2 , i.e. no gap remains between the upper face  31 ′ of the midsole  3 ′ and the sole section  22 . 
     When the midsole  3 ′ is adhered to the sole section  22 , a connection is simultaneously made between the connecting element  34 ′ and the connecting element  25  of the upper-side part of the air intake duct  24 . It is made easier to mount the midsole  3 ′ on the upper  2 , including connecting the connecting elements of the air intake duct, in that, as already mentioned, the lower face of the upper is arranged upwards. 
     After the midsole  3 ′ has been adhered to the sole section  22  of the upper  2 , the last having the clamped upper  2  is rotated such that the lower face  32 ′ of the midsole  3 ′ faces the upper face  41  of the outsole  4 . This is shown in  FIG. 8C . Subsequently, the lower face  32 ′ of the midsole  3 ′ is placed onto the upper face  41  of the outsole  4  such that it is positioned in the indentation by means of the edge  42 . The result is shown in  FIG. 8D . Preferably, the connection between the midsole  3 ′ and the outsole  4  is also an adhesive bond, which, however, does not need to be provided over the entire surface. It merely serves to fix the outsole  4  to the midsole  3 ′. After the upper  2 , the midsole  3 ′ and the outsole  4  have been interconnected, as shown in  FIG. 8D , an injection mold is closed around the shoe and the plastics material of the edge sole region  5  is then injected such that the surface regions of the upper face  41  of the outsole  4  not covered by the midsole  3 ′, the lateral outer surfaces of the midsole  3 ′ and the regions of the sole section  22  not covered by the midsole  3 ′ and adjacent lateral surface regions of the upper  2  are overmolded with the edge sole region plastic. The result is shown in  FIG. 8E . 
       FIGS. 9A and 9B  are again schematic sectional views through a shoe  1  produced according to the production method shown on the basis of  FIG. 8A to 8E . The views in  FIGS. 9A and 9B  correspond to those in  FIGS. 4A and 4B , with the following differences. The recess  36 ′ for forming the bellows of the air pump device and the recesses for the air-guiding ducts  38 ′ are open towards the upper face of the midsole  3 ′ here such that they are closed by the sole section  22  of the upper  2 . Here, the air-guiding ducts  38 ′ of the midsole  3 ′ directly adjoin the openings in the sole section  22  of the upper  2 . In this embodiment, it is preferably provided that the sole section  22  comprises an insole which is reinforced in the heel region above the cavity of the recess  36 ′ which forms the at least one bellows of the air pump device and is designed as a rigid pressure plate which completely covers the recess  36 ′. For example, the insole of the sole section  22  is covered in this region by a strong cardboard or a rigid plastics plate. 
       FIG. 10  shows a phase in the production process of a shoe which is produced according to a modification of the method described with reference to  FIG. 8A to 8E . While the midsole  3 ′ has first been attached to the sole section  22  of the upper  2  in the production according to  FIG. 8A to 8E  in order to subsequently attach this combination to the outsole  4 , in the embodiment according to  FIG. 10  the midsole  3 ′ is first connected to the outsole  4  in order to then fasten this combination to the sole section  22  of the upper  2 .  FIG. 10  shows the phase in which the midsole  3 ′ is already connected to the outsole  4  and this combination is arranged above an upper  2  pointing upwards together with the sole section  22 . Here, the connection between the midsole  3 ′ and the outsole  4  does not need to be a full-surface adhesive bond; it is sufficient to fix the midsole  3 ′ to the outsole  4 . After the phase shown in  FIG. 10 , the adhesive bond is then made between the upper face  31 ′ of the midsole  3 ′ and the upwardly pointing lower face of the sole section  22 , with either the upper face  31 ′ of the midsole  3 ′ or the lower face of the sole section  22  or both surfaces having previously been coated with adhesive. The upper face  31 ′ of the midsole  3 ′ and the lower face of the sole section  22  again have complementary surface profiles in the regions to be connected, such that, during adhesion, there is no gap between the upper face  31 ′ of the midsole  3 ′ and the lower face of the sole section  22  that connects the recesses in the midsole  3 ′ to the environment. 
       FIG. 11A to 11F  are schematic perspective views of the components of a shoe in the various phases of its production following a modification of the first embodiment of the method according to the invention described with reference to  FIGS. 1 to 4B , but first, in the method according to  FIG. 11A to 11F , the midsole  3 ″, the lower face of which comprises recesses, is applied to the outsole  4 ″ provided in a base element  6  of an injection mold and then the upper  2 ″ is mounted on this combination. 
       FIG. 11A  first shows the provision of the outsole  4 ″ by inserting the prefabricated outsole into the base element  6  of an injection mold. In an embodiment that is not shown here, the outsole  4 ″ can also be provided by injection molding in the base element  6  of the injection mold, by the base element  6  being closed at the top during this injection molding by a mold half which corresponds to the profile of the upper face of the outsole  4 ″ to be produced.  FIG. 11A  also shows that the outsole  4 ″ provided comprises two positioning elements  43  on its upper face. After the outsole  4 ″ is provided in the base element of the injection mold, a prefabricated midsole  3 ″ is placed thereon. The lower face of the midsole  3 ″ comprises positioning elements which are complementary to the positioning elements  43  of the outsole  4 ″, such that it is possible to precisely position the midsole  3 ″ which it is placed on. 
       FIG. 12  is a view from below of the midsole  3 ″ shown in  FIG. 11B , the recess  36 ″ for forming the cavity of the bellows of the air pump device and the recesses for the air-guiding ducts  38 ″ being visible in particular in  FIG. 12 . The midsole  3 ″ is also equipped with an air intake duct  39 . 
       FIG. 11C  shows the phase of the production process after positioning the midsole  3 ″ on the midsole  4 ″ lying in the base element  6  of the injection mold. After the midsole  3 ″ has been positioned, as shown in  FIG. 11 , the pre-assembled upper  2 ″ is placed thereon, the lower face of its sole section  22 ″ being placed on the upper face  31 ″ of the midsole  3 ″. According to  FIG. 11E , the injection mold, which is schematically shown here, is then closed by the side parts  7 , such that then the surface regions of the upper face of the outsole  4 ″ that are not covered by the midsole  3 ″, the lateral outer surfaces of the midsole  3 ″ having the intake duct  39 , and the regions of the lower face of the sole section  22 ″ that are not covered by the midsole  3 ″ and comprise the adjacent lateral surface regions of the upper  2 ″ are overmolded with an edge sole region plastic, in order to interconnect the upper  2 ″, the midsole  3 ″, and the outsole  4 ″. The result of this connection is shown in  FIG. 11F . 
     As already mentioned, the use of the shoe components upper  2 , midsole  3 , outsole  4  and edge sole region  5  allows the materials used for the components to be adapted to their respective functions. A compressible material (i.e. that can be easily pressed together) having sufficient resilience, for example a PUR foam, is used for the midsole  3 . A compressible and resilient PUR foam material is also preferably used for the edge sole region. The materials of the midsole  3  and the edge sole region  5  preferably have a Shore A hardness of between 40 and 60 Shore, preferably of between 45 and 55 Shore. In the embodiments described above, the bellows of the air pump device is preferably formed by the cavity of the recess  36 , covered by the lower face of the sole section  22  or the upper face  41  of the outsole  4 , without an additional plastics bubble needing to be used. Of course, it is conceivable in alternative embodiments for such a plastics bubble to be inserted into the cavity, which is usually carried out during the pre-assembly of the midsole.