Patent Application
20130233477
The present invention is related to a method for manufacturing at least one part of a sole assembly of a shoe, and to a sole assembly for a shoe.
Products like shoes are typically mass produced in a way that leaves only little room for customization or fine tuning of details in the mass produced shoe. In order to obtain good economy and scale when manufacturing the shoe, the soles of the shoes are mass produced in high numbers and are almost looking the same. For manufacturing a sole of a shoe or the shoe as a whole, typically an aluminium block is milled to become a mould for a sole. Such moulds are expensive in material and work, and have to be made for the left and right foot respectively and for each shoe size. Thus, a considerable number of moulds have to be made for each sole design, which number of moulds in practice makes customization or fine tuning of a single shoe sole unrealistic. On the other hand, customization and fine tuning of single shoe soles may be desirable for the manufacturer to meet particular or changing customer demands.
It is therefore an object of the invention to provide a method for manufacturing a sole assembly of a shoe or parts thereof which is suitable of making customization or fine tuning of mass produced soles economically viable.
According to an aspect of the invention, there is provided a method for manufacturing at least one part of a sole assembly of a shoe according to the features of claim 1, and a sole assembly for a shoe according to the features of claim 21.
In particular, in an aspect of the invention there is provided a method for manufacturing at least one part of a sole assembly of a shoe comprising the steps of directing a laser beam towards the at least one part of the sole assembly comprising a polymer material and creating at least one of an opening, passage, cavity or engraved pattern in the at least one part of the sole assembly by means of the laser beam, or removing material from the at least one part of the sole assembly by means of the laser beam.
In a further aspect, there is provided a sole assembly for a shoe comprising at least one part which is manufactured from a polymer material, wherein the at least one part of the sole assembly comprises at least one of an opening, passage, cavity or engraved pattern created by means of a laser beam.
According to the invention, a laser beam generated by a laser apparatus may be used in the manufacturing of at least one part of a sole assembly of a shoe, for example for customizing the sole to particular needs or for working on particular parts of the sole assembly for creating one or more openings, passages, cavities or engraved patterns, or for removing left-overs of sole material from the sole casting or injection process. Advantageously, it is not necessary that a number of different moulds are made for manufacturing various sole designs, or that special moulds are manufactured which are provided with a number of pins or other projecting members for creating openings or passages. Rather, a single laser apparatus is sufficient for customization of different sole assemblies or parts thereof, which laser apparatus can be used not only for one type of sole design, but for various types of soles. By means of controlling the laser apparatus in a particular way, variable customization of mass produced shoe soles over various shoe types depending on the current needs may be performed in an economically viable way.
The use of laser in relation to shoes is essentially known in connection with roughing or engraving of the shoe upper, as well as for purposes of cutting leather. Laser is also used for measurement of foot size in order to manufacture custom made shoes. However, laser in connection with manufacturing of shoe soles which comprise polymer material has not been applied. As compared to an upper of a shoe, a polymer based sole is a different element which requires that the polymer material be manufactured and treated in a way that it is still able to withstand a wide variety of environmental influences which are particular for the shoe sole being the part of the shoe which carries the whole weight of the wearer and contacts the ground. The inventors of the present invention found that a polymer based sole of a shoe may be manufactured by use of a laser beam appropriately without compromising the properties of the sole with respect to these environmental influences.
As an example for creating an engraved pattern in the sole for customizing the same, the (mirrored) name of the human wearer may be engraved into the sole in the tread or on the side of the sole. According to another example, the letters of the manufacturer may be engraved, e.g., in the tread of the outsole. Also the shoe size could be engraved. Further, e.g. the country of origin, i.e. the country where the shoe was manufactured, could be engraved. Complex patterns or images such as a digitized photo of the wearer are also possible implementations for using a laser beam in the manufacturing of shoe soles.
A further advantage of using a laser in the manufacturing of a sole is that steps in the manufacturing process of the sole can be automated or improved in different ways. Thus, for example, the laser can be used for fine tuning or trimming the sole if left-overs from the sole casting or injection process are still adhered to the sole. E.g., the sprue extending from the heel of the sole and resulting from the injection of polyurethane can be cut away with the laser. This process is typically a manual operation, wherein by means of the present invention this process can also be automated and improved, such as the accuracy of removing left-over material. Further, for obtaining fast and simplified manufacturing steps, the laser can be used for creating openings, passages or through-holes, or cavities in the sole. For example, openings or passages can be used for ventilation purposes whereby the interior of the shoe is in air communication with the exterior for gaining breathability of the sole assembly.
According to an aspect of the invention, to increase the life time of the shoe sole, the at least one part of the sole assembly comprises a polymer material which is resistant to hydrolysis or contains material which is resistant to hydrolysis. The inventors found that the heat generating laser beam may destroy a potential protecting surface layer of the polymer material and hereby opens the material for entry of water. If the polymer material is not resistant to hydrolysis, the hydrogen atoms of water may react with the carbon atoms and any radicals of the polymer, if any, and may cause breakage of the chemical connections to the radicals over time hereby finally causing hydrolysis. As a result, the sole becomes pulverized over time and prone to mechanical damage at external impacts. After a certain period of time, it may be that the shoe cannot be used anymore. This problem is solved by using sole material that is resistant to chemical hydrolysis, or a sole material that contains material resistant to chemical hydrolysis.
According to an embodiment of the invention, the at least one part of the sole assembly comprises a polyurethane material based on a mixture of an isocyanate and a polyether.
According to another embodiment of the invention, the at least one part of the sole assembly comprises a polyurethane material based on a mixture of an isocyanate and a polyester based polyol, wherein one or more of hydrolysis preventing additives are added to the polyol. For example, one or more of the following hydrolysis preventing additives are added to the polyol: calcium and magnesium carbonate, or calcium and magnesium stearate, preferably in the range of 1% to 10% of the weight of the polyol including process additives, if any.
The inventors found that chemical hydrolysis may happen over the life time particularly in polyester based polyurethane sole material but not in polyether based sole material. The heat generating laser beam may destroy any protecting surface layer of the polyester based polyurethane and hereby opens the material for entry of water. The hydrogen atoms of water then react with the carbon atoms and the radicals of the polyester, which may cause breakage of the chemical connections to the radicals hereby finally causing hydrolysis.
Thus, according to an aspect of the invention, a polyurethane sole material based on a polyether polyol can be used to increase the life time of the shoe. Alternatively, a polyurethane material based on a polyester polyol can be used if hydrolysis preventing additives are added to the composition. Such additives can be calcium and magnesium carbonate totaling a weight percentage in the range of 1%-10% of the weight of the polyester polyol including process additives. Or it can be calcium and magnesium stearate with a total weight percentage of 1%-10% of the weight of the polyester polyol including process additives. This mixture will create a kind of pH-buffer which makes the sole more alkaline and prevents the eroding effect of an acidic hydrolysis attack on polyester based polyurethanes with no hydrolysis preventing additives.
In general the concentration of any hydrolysis preventing additives in the mixture should be low, because they may otherwise damage the reaction. A preferred method used for manufacturing a polyurethane based part of a sole makes use of, in a known way, two tanks, designated for example as tanks A and B. Tank A comprises the polyol, e.g. polyester or polyether, and process additives. According to the invention hydrolysis preventing additives may be added if the tank contains polyester. Tank B comprises the isocyanate. The materials of tanks A and B are typically mixed in the ratio A/B of 100 kg to 121 kg when injected into the sole mould. Alternatively, the materials of tanks A and B can be mixed as a pre-polymer prior to injection into the sole mould.
According to an embodiment, the at least one part of the sole assembly comprises a thermoplastic polyurethane, or a mixture of cork and polyurethane. The invention can be used on soles consisting only of polyurethane, or soles consisting of a mixture of polyurethane and cork. Particularly, a sole consisting of a thermoplastic polyurethane (TPU) can be used because the chemical properties are not changed by the laser process. This is due to the chemical crosslinks in the TPU.
The sole assembly can be adhered directly to the shoe upper in a direct injection process where the polyurethane is injected into a mould where the upper is placed, or the sole assembly can be pre-manufactured and in a later step adhered to the upper by means of gluing. The at least one part of the sole assembly manufactured with the aid of a laser beam can be the whole sole assembly attached below e.g. an insole of an upper assembly, i.e. comprising a tread or outsole engaging with the ground, or it can be the tread or outsole itself, or it can be a midsole which has an outsole attached to it or any other part of the sole. Possible outsoles can be made of TPU, Styrene Butadiene Rubber (SBR rubber), latex, pure cork, or cork pieces mixed with polyurethane.
According to a further embodiment of the invention, the method comprises the step of creating at least one opening or passage by means of the laser beam such that the opening or passage is connecting an interior of the shoe with an outside of the shoe e.g. for air ventilation of the shoe. Thus, such passages can be manufactured custom-made and in a precise way without requiring special moulds. For example, the laser beam creates said passage in a lateral side of the at least one part of the sole assembly, particularly in a lateral side of a midsole of the sole assembly.
For example, the opening or passage has a diameter in the range of 0.1 to 5 millimeters.
According to an embodiment, the point of laser beam focus is placed on a side wall of the at least one part of the sole assembly.
In a further embodiment of the invention, the method further comprises the steps of providing a ventilating sole element having a structure or material allowing for air flow through it, and creating at least one opening in a side wall of the ventilating sole element by means of the laser beam such that the opening is enabling air ventilation from an interior of the ventilating sole element to an outside of the shoe. According to an embodiment, the point of laser beam focus is placed on the side wall of the ventilating sole element.
The method may also comprise the step of creating at least one opening or passage in a side wall of a ventilating sole element, which has a structure or material allowing for air flow through it, by means of directing the laser beam through at least one opening or passage in the outsole or midsole (e.g., a surrounding sole element).
Furthermore, the method comprises the steps of creating a ventilating structure in a ventilating sole element, e.g. channels or passages.
Accordingly, the method of the invention is suitable for manufacturing a sole assembly for a wide variety of usage scenarios. The different components such as midsole, ventilating sole element, surrounding sole element and/or outsole etc., may be manufactured for a wide variety of usage scenarios in a way that they fulfill the particular demands. The interconnection between the structure or material of a ventilating sole element or a midsole and any passages in a surrounding sole element or in an outsole is made in a manufacturing step in which openings or apertures are made in a wall of the ventilating sole element or midsole by directing the laser beam through the passages. In this way, air and water vapour may effectively be transferred out of the shoe via the ventilating sole element or midsole and the passages in the outsole or surrounding sole element, since the laser formed openings in the ventilating sole element or midsole are then exactly aligned with the passages in the outsole or surrounding sole element.
The method of the invention may further comprise the step of creating at least one opening or passage in an outsole, midsole or surrounding sole element of the sole assembly. For example, the opening or passage has a diameter in the range of 0.1 to 5 millimeters.
According to an embodiment, the at least one part of the sole assembly comprises TPU, styrene butadiene rubber, latex or cork material, or any combination thereof.
The at least one of an opening, passage, cavity or engraved pattern may be formed in a lateral, medial, front or back side of the at least one part of the sole assembly.
According to an embodiment, the method may further comprise the step of creating at least one opening or passage in a side wall of a ventilating sole element, which has a structure or material allowing for air flow through it and which is at least partially surrounded by at least a portion of the sole assembly with at least one passage in it, by means of the laser beam directed through the at least one passage in the portion of the sole assembly surrounding the ventilating sole element, in particular the outsole, the midsole or the surrounding sole element.
In a possible implementation of the invention, the laser beam is controlled to generate a power output in a range between 50 W and 500 W at a speed in the range of 20 mm/s to 2000 mm/s.
For example, the laser beam is applied in a laser beam cycle which repeatedly scans over a portion of the at least one part of the sole assembly, wherein the laser beam cycle is repeated within the range of 5 to 30 times.
The method may include, in an embodiment of the invention, providing a controllable robot which is adapted to place the at least one part of the sole assembly in front of the laser beam, wherein the laser beam through a series of repeated laser cycles on the at least one part of the sole assembly creates the at least one of an opening, passage, cavity or engraved pattern, or removes material from the at least one part of the sole assembly.
For example, a point of focus of the laser beam is changed in steps in the following way: a) placing the target of the at least one part of the sole assembly in a point of focus, b) performing a first series of laser cycles which generate a channel with a first penetration depth, c) moving by means of the robot said at least one part of the sole assembly towards the point of focus so that the bottom of the channel is placed in the focus point of the laser beam, and d) performing a second series of laser cycles which deepens the channel in the sole.
According to a further embodiment, a first laser workstation may be used for roughing an upper of the shoe, whereafter the upper is placed in a mould and sole material is injected onto parts of the upper and hereby adhered to the upper, and whereafter the first laser workstation or a second laser workstation is used for creating the at least one of an opening, passage, cavity or engraved pattern, or removing material from the sole material.
For example, a robot is adapted to hold the element comprising at least one part of the sole, in front of a laser apparatus and the laser apparatus through a series of repetitive shots at the element burns away material of the element for making at least one opening, cavity, passage or a design in the element. The at least one opening, cavity or passage may have a length of between approx. 0.5 to 50 mm. The opening, cavity or passage may be formed as an air channel or guide for supporting an air flow therein from one end of the opening to the other.
For such use, different types of lasers can be used as, e.g., diode lasers, infrared lasers and CO2 lasers. In the following an embodiment of the invention will be described which makes use of a CO2 laser. CO2 lasers work with a wave length in the range of 9.4-10.6 micrometers. Usually, a laser is controlled by way of three parameters, such as speed (of the beam), quantity of energy and wavelength.
Making openings or patterns with a laser, particularly a CO2 laser, is possible in elastomeric, i.e. meltable materials such as polyurethane (PU), thermoplastic polyurethane (TPU), ethylene vinyl chloride (EVA), polyvinyl chloride (PVC) or rubber. In these materials the laser will, using a sufficient amount of energy, burn away the targeted sole material which will disappear without leaving debris.
Use of a laser for roughening of a shoe upper is described in DE 10 2009 049 776 A1.
When roughing shoe uppers of leather, techniques exist according to which the laser beam is swept across the surface of the upper in a predetermined time and with a predetermined amount of energy. The beam is swept by a mirror in the laser apparatus that deflect the laser beam in order to reach the surface of the shoe to be roughened while the robot holds the shoe upper in a fixed position during sweeping of the beam. The robot places the shoe in front of the laser and then the mirrors move the beam through the leather. During this process the robot is stopped. If the curvature of the shoe upper becomes too great, i.e. if the focus point of the laser beam is removed too much from the targeted spot, the shoe upper is repositioned anew by the robot. After repositioning, the new target spot is again in focus, and the laser sweeps across one or more spots.
A problem occurs, however, when deep openings in a (elastomeric) sole or part thereof shall be made. Such openings have a depth which is by far larger than the relatively shallow roughing made on leather uppers by the laser. For example, a lasered channel in a leather upper has a depth of 0.5 mm, whereas an opening in the sole may extend from the medial side of the sole to the lateral side, i.e. has a length of 50 mm. If the mirror-solution, which is used for roughing of the upper, with deflecting the laser beam is used for making openings in an element of a shoe, a problem may occur in opening any borders, such as the side wall of the ventilating sole element which may need to be provided with deep and narrow channels.
When using the mirror-solution the deflection of the beam may create an acute angle between the beam itself and the surface of the element. When applied for connecting narrow and elongated channels of lateral passages of a surrounding sole element to the structure or material of a ventilating sole element, such acute angle drives the beam sideways into the channel side wall of the lateral passages and it does not reach the bottom thereof facing the ventilating sole element.
On the other hand, according to an embodiment of the invention, the opening is made in an element of the sole, such as in the side wall of the ventilating sole element, by keeping the beam of the laser in a fixed direction (i.e. no sweeping of the laser beam) and letting the robot position the target spot of the element aligned with the center of the laser lens. This means that the laser beam will not be swept as when roughening a shoe upper. Instead only the robot arm holding the sole is moved. However, there may be applications in which a mirror may be used when making openings or making patterns in an element of a sole.
This method is thus especially useful if the laser beam is shot through a cylindrical passage already present in the sole as is the case if, e.g., the end of a passage in a sole, such as in a surrounding sole element, has to be opened.
According to an example a number of openings are made in a polyurethane sole. The sole material is polyurethane from manufacturer BASF GmbH. The polyurethane used has a relatively low density (0.35 g/cm3) and is often used for shoe midsoles. The following steps may be applied in various ways, in combination or individually depending on the particular implementation and needs. The terms “first, second . . . ” are used only for designation purposes and shall not impose any limitations as to sequence or numbers of steps.
(1) In a first step a sole is placed in front of the laser by a robot. (2) In a second step the target spot on the sole or element thereof is placed orthogonally to the laser beam by the robot. (3) In a third step the laser beam hits the sole material at an angle to the sole (element) surface of approximately 90 degrees. (4) In a fourth step the focus of the laser is kept constant, i.e. unchanged. (5) In a fifth step a series of laser shots towards the target spot is performed (e.g., multiple shots in the same place). The number of shots may be between 1 and 10 depending on the power of the laser and material and depth of entry. Duration per shot may be approx. 1 ms.
When applied for connecting the lateral passages of a surrounding sole element to the structure or material of a ventilating sole element, the laser shots may result in a diameter of the openings in the side wall of the ventilating sole element which equals the diameter of the passages made by pins of an injection mould in the surrounding sole element during injection. In order to get the desired diameter the number of shots can be varied as can the relative position of the shots. During a shot cycle the target can be moved a few millimeters (e.g., the robot moves), and the diameter will increase. In a further step, the robot moves the sole to the next target spot, i.e. the process goes to the second step (2) above.
In relation to the ventilating sole element, the opening of the side wall of the ventilating sole element with laser leaves no debris. Everything is burned away. Hereby any clogging of the air channels caused during manufacturing of the openings is prevented. The method further has the advantage that it is very fast compared e.g. to drilling out the openings.
In the following, particular embodiments and/or variations of the process making use of a laser for creating openings, passages cavities or patterns in a shoe sole are described:
In order to get a cylindrical opening, passage, cavity or pattern with a clean edge the amount of energy per shot may be increased. The focus point may be kept constant. The first laser shots start with a low energy for making a first opening or similar with a diameter of say 2 mm. The next series of shots has an energy increase of 50% per shot. The opening now has a diameter of 4 mm. The third series of shots has again an increase of energy by 50%, increasing the diameter at the beginning of the opening to 6 mm.
Alternatively, or simultaneously, the point of focus of the laser beam can be amended per shot or per series of shots. After a first series of shots the depth of the opening or similar—may be 3 mm. Now the focus has to be changed and moved 3 mm further inwards in the sole. Change of focus is made via software which controls the movement of the lenses in the laser apparatus.
Further, in order to ensure a well defined opening with a well defined edge, the laser beam can be moved in a spiral shape. Such spiral shape can be elliptical or circular. This functions the following way:
Ideally, in order to create a clean cut in a polyurethane sole, the diameter of the point of focus (spot size) may be between 0.5 mm and 2 mm and the power between 150 watt and 250 watt. It should be noted that these values are to be understood as pure examples without imposing any limitations in connection with the invention.
The robot may serve to position precisely any channels of a ventilating sole element in front of a laser. The robot is one of the preferred solutions because the openings are always in different positions—for instance, the position of a shoe with size 40 is different to the same shoe in size 41. A shoe sole is characterized by 3D-curvatures. It is not only a 2D surface, and therefore the focus point of the laser beam is changed along the 3D surface of the sole.
Aspects of the invention and further embodiments thereof are disclosed in the following description with reference to the drawings, in which:
In the following, exemplary embodiments of a method according to the invention applied in the manufacturing of an exemplary shoe will be described. The skilled person will be aware that various changes or adaptations may be made as far as appropriate and depending on the particular needs of the respective shoe or sole construction.
As described in the following in more detail, the principles of manufacturing of at least parts of a sole assembly of a shoe by means of a laser beam in accordance with the invention may be applied basically to any kind of shoe. In an aspect of the invention, the method may be applied to a kind of sole assembly of a shoe as shown in
The position of a vertical plane including horizontal line Y-Y corresponds to the position of the cross-sectional plane depicted in
The outsole 90 comprises a tread or corrugated structure on its lower surface for improving the grip characteristics of the shoe during walking. The shank 172 is provided in the shoe 300 to give it additional stability. The shank 172 is optional and may be made of metal or any other suitable material. Due to the illustrative nature of
The ventilating sole element 60 comprises a channel structure, in particular a channel grid, at its upper side. The channel structure comprises transverse channels, generally designated with reference numeral 181. Channels 184 cross the transverse channels 181.
A distinction is made between at least one peripheral channel being formed in a peripheral region of the channel structure and longitudinal channels. For the sake of simplicity in describing different shoe constructions, the channels 184 are generally referred to as longitudinal channels, although one or more of the channel cross-sections shown may belong to one or more peripheral channels.
The ventilating sole element 60 has an upper surface 606, a lower surface 604 and a lateral surface 602. In an assembled state of the shoe 300, the lower surface 604 of the ventilating sole element 60 is partly adjacent the shank 172 and partly adjacent the outsole 90, the upper surface 606 of the ventilating sole element 60 is adjacent the comfort layer 40, and the lateral surface 602 of the ventilating sole element 60 is adjacent a lateral inner surface 802 of the surrounding sole element 80. Regarding the engagement/connection of the individual components, more details are given below.
The channel structure, in particular the transverse channels 181, is in air communication with a plurality of openings 55. The openings 55 extend through a side wall of the ventilating sole element 60, particularly they extend from the channel structure of the ventilating sole element 60 to lateral passages 50 of the surrounding sole element 80.
The surrounding sole element 80 has a varying height across its circumference, with the lateral passages being arranged at different heights. In this way, the positions of the lateral passages account for the uneven surface structure of the ventilating sole element 60, which takes into account the wearer's foot and its positioning during walking. Exemplary embodiments of the components are described in greater detail below.
The shoe 301a comprises an upper assembly 8 and a sole assembly 7. The upper assembly 8 has an upper portion 10 and a bottom portion 20. The upper portion 10 comprises, from outside to inside, a breathable outer material 11, also referred to as upper material, a mesh 12, an upper membrane 13, and a textile lining 14. The mesh 12, the upper membrane 13 and the textile lining 14 are provided as a laminate, also referred to as upper functional layer laminate 17. The upper membrane 13 is breathable and waterproof. With all of the upper material 11, the mesh 12 and the textile lining 14 being breathable, i.e. water vapour permeable, the upper portion 10 as a whole is breathable and waterproof.
The upper material 11 may be any breathable material suitable for forming the outside of a shoe, such as leather, suede, textile or man made fabrics, etc.
The upper functional layer laminate (i.e. mesh 12, upper membrane 13 and textile lining 14) may be any suitable waterproof and breathable laminate, such as commercially available GORE-TEX® laminate from W.L. Gore & Associates.
A lower portion of the outer material 11 is comprised of a netband 15. The netband 15 may be attached to the remainder of the outer material 11 through any suitable way of connection, for example stitching or gluing. In the exemplary embodiment of
The bottom portion 20 comprises, from bottom to top, a lower membrane 21 and a supporting textile 22. The textile may be a woven, non-woven or knitted textile, for example Cambrelle®. The lower membrane 21 and the supporting textile 22 are provided as a laminate, also referred to as bottom functional layer laminate 24. The lower membrane 21 is waterproof and breathable. With the supporting textile 22 being breathable, an overall breathable and waterproof bottom functional layer laminate 24 is provided. The bottom functional layer laminate 24 may be any suitable laminate, for example commercially available GORE-TEX® laminate from W.L. Gore & Associates.
The upper portion 10 and the bottom portion 20 are connected to each other at their respective end areas. Particularly, a lower end area of the upper functional layer laminate 17 is connected to a side end area of the bottom functional layer laminate 24. In the embodiment of
The upper functional layer laminate 17 and the bottom functional layer laminate 24 may be positioned end-to-end before being connected and sealed together, as shown in
In the embodiment of
The sole or sole assembly 7 of the shoe 301a, i.e. the portion of the shoe 301a below the upper assembly 8, which consists of the upper portion 10 and the bottom portion 20, is comprised of a ventilating sole element 61, a comfort layer 40 and a surrounding sole element 81.
The ventilating sole element 61 comprises a channel structure 160 that allows for air communication between the upper side of the ventilating sole element 61 and openings 55. Lateral passages 50 extend through a side wall 702 of the surrounding sole element 81 and the openings 55 extend through a side wall 608 of the ventilating sole element 61. For an easier reading of
The cross-sectional view of
In the cross-sectional view of
The u-shape of the longitudinal and transverse channels allows for a good compromise between providing sufficient channel volume for fluid communication and providing a strong ventilating sole element structure for supporting the wearer's foot and transferring the wearer's weight to the ground and/or the surrounding sole element 81. Also, the u-shaped channels can be manufactured easily and quickly, particularly in the case of an injection-moulded ventilating sole element 61, because the rounded channel side walls allow for an easy parting of the ventilating sole element 61 and the mould after the moulding operation. Of course the channels may also be manufactured using a laser beam.
It is pointed out that the channels of the ventilating sole element 61 may have any suitable cross-section that allows for an efficient transfer of water vapour from the upper side of the ventilating sole element 61 to the lateral passages 50 in the surrounding sole element 81. At the same time, the ventilating sole element 61 should provide a stable structure for the sole of the shoe. It is also pointed out that the channels may have varying cross-sections along their length in order to form a channel system having desired properties.
The exemplary embodiment of
The transverse channel 181 connects the longitudinal channels 184 to each other and to the openings 55 and lateral passages 50 in the surrounding sole element 81. At its lateral ends, the transverse channel is equipped with air and moisture discharging ports 182. The air and moisture discharging ports 182 are arranged laterally outside from the laterally outmost longitudinal channel. In particular, the air and moisture discharging ports 182 are arranged directly adjacent the side wall 608 of the ventilating sole element 61. The air and moisture discharging ports 182 are formed by recesses in the floor of the transverse channels 181. In other words, the floor of the transverse channels 181 extends deeper down into the ventilating sole element 61 in the region of the air and moisture discharging ports 182 than throughout the remainder of the transverse channels 181. The air and moisture discharging ports 182 allow for an efficient collection of moisture/water vapour from the inside of the shoe, from where the water vapour can be carried away effectively through the openings 55 and lateral passages 50. All or only a subset of the transverse channels may 181 have air and moisture discharging ports. The ports too may be manufactured by the use of a laser beam.
All or only a subset of the transverse channels 181 may provide for the connection with openings 55 and lateral passages 50. There may also be transverse channels 181 that are not in air communication with openings 55 and lateral passages 50, but end in dead ends. The transverse channels of the ventilating sole element 61, one of which is being shown in
It is pointed out that the transverse channels 181 may have the same, a smaller or greater height than the longitudinal channels 184. They may be channels that reach from the top of the ventilating sole element towards the inside of the ventilating sole element, such that they can also be seen as grooves or tranches. It is also possible that the transverse channels lie below a portion of the ventilating sole element 61 and are therefore not readily visible from the top of the ventilating sole element 61. Also, the longitudinal channels may be grooves, as shown, or channels concealed from the upper surface of the ventilating sole element 61.
In the present embodiment, the channel system 160 of the ventilating sole element 61 is a channel grid. The channels of the channel grid extend from the top of the ventilating sole element 61 to the inside thereof. The channels may be longitudinal channels 184 and transverse channels 181, which intersect for allowing air communication therebetween. The channels may also be diagonal channels, when seen from the top of the ventilating sole element. In general, such a channel grid may have any combination of longitudinal, transverse and diagonal channels.
It is pointed out that any channel structure may be embodied in all other constructions of the remainder of the shoe, in particular in combination with all other upper assembly constructions and all other constructions relating to the remainder of the sole 7.
The lateral passages 50 extend through the side wall 702 of the surrounding sole element 81 and the openings 55 extend through a side wall 608 of the ventilating sole element 61 of the shoe 301a, allowing for air communication between the channel structure of the ventilating sole element 61 and the lateral outside of the shoe 301a. In the exemplary embodiment of
The ventilating sole element 61 of the shoe 301a also comprises a circular lip 101. The circular lip 101 is arranged at the upper lateral edge of the ventilating sole element 61. As the ventilating sole element 61 is a three-dimensional structure, the circular lip 101 surrounds the perimetric upper edge of the remainder of the ventilating sole element 61. In other words, the circular lip 101 is arranged at the periphery of the upper lateral portion of the ventilating sole element 61. Accordingly, the term circular is not intended to be understood as referring to the shape of a circle. Instead, it is understood as referring to a structure surrounding an inner space or as referring to a loop structure. However, the term is also not intended to require a closed lip or collar structure. The lip may be continuous around the perimeter of the ventilating sole element 61, but is may also be made of a plurality of spaced apart lip sections distributed around the perimeter of the ventilating sole element 61. The lip also does not need to be arranged right at the upper lateral edge of the ventilating sole element 61. It may also be attached to the lateral surface 602 or the upper surface 606 thereof. However, a positioning in the vicinity of an upper circumferential edge of the ventilating sole element may be beneficial, as will be discussed below.
The circular lip 101 may perform one or more of the functions described as follows. As shown in
It is also possible that the ventilating sole element 61, comprising the circular lip 101, is attached to the upper assembly by gluing the circular lip 101 onto the upper assembly 8 or by effecting an attachment between the circular lip 101 and the upper assembly 8 through a local injection-moulding operation in the region of the circular lip 101, particularly only in the region of the circular lip 101.
The upper portion of the surrounding sole element 81 is located above the circular lip 101 of the ventilating sole element 61, i.e. below a part of the bottom functional layer laminate 24, as well as underneath the circular lip 101 and underneath a part of the upper portion 10 of the upper assembly 8 as well as adjacent a part of the upper portion 10 of the upper assembly 8 that is arranged in a substantially vertical direction. In other words, the surrounding sole element 81 wraps around the corner of the upper assembly 8 where the inside of the shoe is patterned to match a wearer's foot. In yet other words, the surrounding sole element 81 covers a part of the underside of the upper assembly 8 as well as parts of the lower lateral sides of the upper assembly 8. Sole material of the surrounding sole element 81 is penetrated through the netband 15, through the strobel stitch 30, through the mesh 12, onto the upper material 11, onto the upper membrane 13, around at least a portion of the circular lip 101 and onto the bottom membrane 21. This penetrated sole material seals the strobel stitch 30 in a waterproof manner on the one hand and attaches the ventilating sole element to the upper assembly 8 on the other hand. The sealing provides a completely waterproof upper assembly 8 made up of the upper functional layer laminate 17 and the lower functional layer laminate 24 surrounding the interior of the shoe and being sealed in a waterproof manner to each other. The sealed upper functional layer laminate 17 and bottom functional layer laminate 24 form a waterproof, breathable functional layer arrangement. Thus the upper assembly 8 is waterproof, which allows the sole assembly to be non-waterproof. The surrounding sole material also penetrates through the connection 30 to the upper sides of the bottom functional layer laminate 24 and the upper functional layer laminate 17, which is illustrated by the circle sector covering the upper side of the strobel stitch 30 and extending onto the bottom functional layer laminate 24 and the upper functional layer laminate 17 in
Above the ventilating sole element 61, a comfort layer 40 is provided in the shoe 301a. The comfort layer 40 is positioned on top of the ventilating sole element 61. The comfort layer 40 may be loosely positioned there or may be attached before further manufacturing of the shoe. Such attachment may be achieved by a spot-gluing or circumferential gluing or by gluing making use of breathable glue, such that the flow of water-vapour from the inside of the shoe to the ventilating sole element 61 is not prevented. Also, the full surface of the ventilating sole element 61 can be glued, and in order to prevent glue to enter the channels a highly thixotropic glue should be used. The comfort layer 40 is inserted for increasing the soft walking feel for the wearer, particularly for ensuring that the wearer does not feel bothered by the channel system 160 of the ventilating sole element 61. In the exemplary embodiment of the shoe 301a, the comfort layer 40 has a greater lateral extension than the channel system 160 of the ventilating sole element 61 and extends somewhat above the region of the circular lip 101. However, the comfort layer does not extend to the lateral edges of the circular lip 101 where it is attached to the upper assembly 8. In general, the comfort layer may have the same or smaller or larger lateral dimensions as/than the ventilating sole element.
The ventilating and surrounding sole elements are produced and attached to the upper assembly 8 in a several stage process. As a first step, the ventilating sole element 61 is produced, for example through injection-moulding of a polyurethane (PU) into a mould with the channels being produced either by the mould being shaped accordingly or by the use of a laser beam. Polyurethane is one of a plurality of suitable materials that can be used in order to form a ventilating sole element 61 that has high stability to support at least a portion of the weight of the wearer during use, such as during walking, while having some flexibility in order to enhance the wearer's comfort during walking. Depending on the preferred use of the shoe, a suitable material can be chosen. Examples of such materials besides polyurethane is EVA (Ethylene Vinyl Acetate). etc.
As a next step, the comfort layer 40 is placed on top of the ventilating sole element 61 and attached to it using an adhesive. The ventilating sole element 61 and the comfort layer 40 are then placed in the desired position with respect to the upper assembly 8 in a mould, wherein the surrounding sole element material is injection-moulded onto the upper assembly 8 and the ventilating sole element 61. In this way, the surrounding sole element 81 adheres to the upper assembly 8 as well as to the sole ventilating element 61, such that a lasting, integral joint of these elements is achieved through the sole material of the surrounding sole element 81. Suitable materials for the surrounding sole element are polyurethane, EVA, PVC or rubber, etc.
In the embodiment of
In the exemplary embodiment of
Even though, according to the exemplary embodiment of
In the following, an exemplary method for manufacturing a shoe in accordance with principles of the invention will be described. The skilled person will be aware that various changes or adaptations may be made in manufacturing the shoe as far as appropriate and depending on the particular needs of the respective shoe construction.
In a process of forming an upper assembly, a bottom portion 20 of the upper assembly is attached to an upper portion 10 thereof. This can be done in any suitable way, for example using commonly known methods such as gluing, stitching etc. For example, the bottom portion may comprise a breathable insole or a waterproof, breathable functional layer laminate with a membrane being waterproof and water vapour permeable. The bottom portion may extend between lower end areas of the upper portion such as shown in the examples of
In the examples of
In the process of forming a sole assembly, an outsole, e.g. of rubber, is made in a respective manufacturing step as commonly known. The rubber is vulcanized and shaped into an outsole. Afterwards, the outsole may optionally be chemically primed by brushing “TFL Primer” (commercially available from the company Forbo Adhesives) on the surface facing the foot. Priming is carried out on open rubber cells in a well known manner to improve the connection to the polyurethane of the ventilating sole element which is later injected. After such priming, glue (for example, Helmipur® GPU from Forbo Adhesives) is applied to that area of the outsole where the ventilating sole element is to be placed later. The outsole is dried for a particular period of time as necessary, for example half an hour at 25-40° C.
In a further step, the outsole is then placed on a piston of a mould, which is in the present embodiment a first injection form or mould and is shaped to mould the ventilating sole element. An exemplary injection mould 210 is shown in
Afterwards, the material forming the ventilating sole element, such as polyurethane, is injected into the mould 210. In an embodiment of the invention, this may be the same polyurethane which is used for a surrounding sole element (which may also be seen as a midsole) later on. In another embodiment the polyurethane of the ventilating sole element is softer (Shore A value of e.g. 30-45) than a polyurethane used for the surrounding sole element (Shore A value of e.g. 45-65). This increases comfort for the wearer. During injection the formed ventilating sole element is bonded to the outsole. After completion of the injection process, these two components now form a monolithic entity, as can be seen in
The manufacturing steps as described above may be performed and finished in a particular manufacturing site independently from other parts of the shoe, for example by a sub-supplier, who will deliver to the shoe manufacturer, for instance, a finished semimanufactured product comprising the ventilating sole element attached to an outsole. An embodiment of a ventilating sole element 161 attached to an outsole 191 is shown in
As illustrated in
The ventilating sole element with the outsole and the comfort layer is then placed in an injection mould, such as a second injection mould 220 as shown in
At the beginning of the moulding process, the last with the upper portion 10 of the shoe is lowered into the second injection mould 220. The bottom piston 222 is then raised until the ventilating sole element has firm contact with the bottom portion 20 of the shoe upper assembly placed on the last. The contact between ventilating sole element with comfort layer and the bottom portion 20 must be so tight that polyurethane from the upcoming injection does not enter between bottom portion 20 and comfort layer. In order to achieve a tight sealing a lip extends vertically from the surface of the ventilating sole element. The lip could be arranged around the full upper circumferential edge of the sole element, but preferably a U-shaped lip of approx 2 mm height is made in the heel area, and a 1 mm high lip is made in the forefoot area. When raising bottom piston 222 against bottom portion 20 an extra mechanical pressure is exerted on the lip in order to deform it a bit. Due to the force impact the lip will bend outside and away from the ventilating sole element, and with the aid of the comfort layer make a tight seal which prevents entry of polyurethane. After raising the bottom piston the side frames with pins 221 close the mould 220, as shown in
Thereafter, an injection with surrounding sole material, particularly PU, is made, hereby creating a surrounding sole element. After a certain curing time (e.g. 3.5 minutes) the side frames are opened and last with the shoe is lifted. Any remaining sprue is manually removed from the surrounding sole element with a knife or automatically with a laser beam.
In a subsequent step, openings 55 are made in the side wall of the ventilating sole element, e.g. with a laser beam as outlined in more detail below with reference to
According to another embodiment, if no pins 221 are provided in the second injection mould 220, the lateral passages 50 in the surrounding sole element and the openings 55 in the side wall of the ventilating sole element may be made with a laser beam which removes wall material appropriately, for example in a process as described in more detail below.
The creation of openings 55 in the side wall of the ventilating sole element connects the lateral passages 50 of the surrounding sole element to the structure or material of the ventilating sole element, so that water vapour can flow and/or diffuse through the bottom portion of the upper assembly and then flow through the structure or material of the ventilating sole element together with the air flowing therethrough and then through the lateral passages in the surrounding sole element to the outside of the shoe, that is the ambient air. The structure or material of the ventilating sole element and the lateral passages in the surrounding sole element are interconnected by making apertures or openings in the ventilating sole element through the lateral passages, so that thereafter there is a reliable path for air to communicate between the structure or material of the ventilating sole element and an outside of the surrounding sole element, that is the ambient air.
In the following, a possible implementation for making openings, passages or cavities in a part of a sole assembly of a shoe, or for removing material from a sole assembly is described by way of examples.
For example, in the manufacturing of at least one part of a sole assembly the following two embodiments of laser work stations may be used. First as shown in
For example, both laser workstations use a CO2 laser manufactured by the company Synrad, which is of the Firestar series, model FSF201SB (dual tube laser). It is able to give a maximum of 700 W at wavelength 10200-1060 nm (EN 60825-1), but tests were made in the range up to 300 W. The scan heads 72 and 94 used are manufactured by the company Raylase AG. The laser can be run in either continuous wave power output mode (CW) with a lower maximum output, or in a pulsed wave power output mode (PW) with close to maximum power output. In PW mode the modulation frequency is up to 25 kHz and the duty cycle variable, but typically set to 50%. The programming language used for the laser work station 70 is Visual Basic, and after compiling the program, the software is downloaded to the laser machine. The laser work station 90 uses a programming software developed by the company Raylase AG. If images are to be engraved in a sole, different data formats can be used, e.g. the well known formats jpeg or dxf which can be loaded into the programming software of both laser work stations.
The polyurethane used in the tests below is based on polyester. Similar tests have been made with polyether based polyurethane with the same or nearly the same results. All tests were made in PW mode.
Generally, a laser beam of a laser apparatus for being used in accordance with aspects of the invention can be controlled with several parameters input to the laser apparatus, namely continuous wave (CW) mode or pulsating wave (PW) mode, power (W), speed (mm/s), number of cycles and focus control. Controlling the point of focus, i.e. of maximum power, can be made via the laser apparatus itself; the apparatus typically has a scan head with mirrors for moving the laser beam, and by adding an extra lens the point of focus can be moved along a z-axis. Alternatively, focus control can be made by moving the target into and out of focus, e.g. through use of a controllable robot arm. Both continuous wave and pulsating wave mode can be used; the pulsating wave modus mainly creating dots, whereas the CW mode is preferred for creating lines without showing the dot effect. The power of the laser is varied in the range of 5% to 100%. In the examples given below the power range was chosen up to 300 W, but higher power can also be used. The speed of the laser beam is the speed with which the beam moves across the surface of the respective part of the sole. In our experiments we worked in the range of 50 mm/s to 16000 mm/s. The number of cycles denotes how many times a predetermined route of the laser beam is repeated, or how many shots are made in the same place. For example, for making a cylindrical through-hole, opening or passage the laser beam will describe in the respective part of the sole a circle in a first cycle, then repeat the circle in a second cycle and so on until the hole, opening or passage has been created. In our experiments the number of cycles has been in the range 5 to 30. For controlling the width of a line when engraving letters or a drawing, the predetermined route of the laser beam can be offset, e.g. 0.5 mm, to one side after finishing the first series of cycles. Then a second series of cycles is executed. In this way a wider line is created.
When lasing in a respective part of the sole, however, some unwanted effects may occur. If lasing is done with too high energy, with too many cycles or too slowly, melting of the sole material in the area of lasing can occur. The result of this melting is an unwanted shining of the areas lasered, and especially the PU also sometimes gets sticky. The shining effect in letters or images can be alleviated by afterwards filling or covering the bottom of the lasered channel with paint. This enhances also the visibility of the lasered letters or image. Alternatively, the shining can be avoided by finding through experiments the best settings of speed, power and number of cycles. Another side effect is in relation to creating cylindrical through-holes or passages in the sole. The circular area next to the edge of the hole or passage where the laser beam enters shows in some situations melting effects; the sole material is in these areas slightly deformed and shiny. This is especially the case if holes with a large diameter (>5 mm) are to be made, because a high amount of energy is needed.
In the following, a number of examples and results thereof are described:
A PU sole with a polyurethane based on polyester contains hydrolysis preventing additives calcium and magnesium in a concentration of 5% of the weight of the polyol of a tank A. The polyol contains both process additives and hydrolysis preventing additives. In a tank B the isocyanate (MDI 4.4 (Methyl Di Isocyanate)) is contained, and a mixture of A and B in the ratio of 100 to 121 is injected into a sole mould. The polyurethane has a density of 0.5 g/cm3, a shore A hardness of approximately 41, and free density rise of 300 gram/liter.
In order to engrave the letter “A” with lines five points of the A were defined, see
From point 200 to 210: laser on
From point 210 to 220: laser on
From point 220 to 230: laser off
From point 230 to 240: laser on
In another test, the letter “A” was then engraved through lasing into a smooth surface of the PU sole. Laser workstation of
In another test, the edge 250 was sharp and acceptable, but the bottom 251 of the channel was rough showing peeks and valleys in the surface and clear melting effects, see
In this case too much heat was generated in target area of the PU sole. In a further test an A in outline was generated, see
A logo “ECCO with a stripe” (
A lion image 430 (
A grey outsole of styrene butadiene rubber (SBR), intended to be adhered to a polyurethane midsole and having a profiled tread, was used. The thickness of the outsole varied between five and two millimeters. A circle with a diameter of four centimeter was lasered in the tread—by the variable speed laser workstation of
A black latex outsole with a thickness of 2 millimeters is intended to be adhered to a PU midsole as the tread. The latex outsole was lasered by the workstation of
A sole consisting of a mixture of small pieces of cork and PU was lasered by the
The laser workstation of
This trial concerns making a through-hole or passage in a PU sole which PU has the same characteristics as described under example 1. The approx. 12 mm thick PU sole was subjected by the laser workstation of
Further trials for making through-holes in a PU sole were made. A 1 mm hole was made in a 15 mm PU sole in the vertical direction of the sole. The through-hole had a sharp edge and there was no debris left. The entry of the hole was circular with a 1 mm diameter, whereas the exit hole was a bit smaller, approx. 0.8 mm. Thus the laser beam basically creates a conical channel or passage when creating a hole. The laser power was set to 100%, laser speed 500 mm/s and the number of cycles was 5. This size of holes is well-suited for a sole which has to have ventilating characteristics.
Several small through-holes or passages can thus be distributed across the surface of the tread of a sole or across the bottom or side surface of a midsole. Through these holes, which can number between e.g. 25 to 200, the sweat and moisture from the interior of the shoe can be guided to the exterior of the shoe, hereby improving the climate comfort of the foot.
In a further trial with the same parameters as above, but with only one cycle, the result was a hole or cavity of 1 mm diameter and 12 mm deep, i.e. not a through-hole. In an even further trial a 4 mm through-hole was made with power set to 100%, speed 50 mm/s and number of cycles 5. The through-hole showed the same conical characteristic as described above.
A laser workstation according to
A laser workstation according to
For example, the opening was made in the side wall of the ventilating sole element by keeping the beam of the laser in a fixed direction (i.e. no sweeping of the laser beam) and letting the robot position the target spot of the element aligned with the center of the laser lens. This means that the laser beam was not swept. Instead only the robot arm holding the sole was moved. However, there may be applications in which a mirror may be used when making such openings in an element of a sole.
In
According to an example a number of openings can be made in a polyurethane sole. The sole material used may be Elastollan™ from manufacturer Elastogran GmbH. Elastollan has a relatively low density (0.35 g/cm3) and is often used for shoe midsoles. The following steps may be applied in various ways, in combination or individually depending on the particular implementation and needs.
(1) In a first step the sole target is placed in front of the laser by the robot. (2) In a second step the target spot on the sole or element thereof is placed orthogonally to the laser beam by the robot. (3) In a third step the laser beam hits the sole material at an angle to the sole (element) surface of approximately 90 degrees. (4) In a fourth step the focus of the laser is kept constant, i.e. unchanged. (5) In a fifth step a series of laser shots towards the target spot is performed (e.g., multiple shots in the same place). The number of cycles may be between 1 and 10 depending on the power of the laser and material and depth of entry. Duration per cycle may be approx. 1 ms.
When applied for connecting the lateral passages of the surrounding sole element to the structure or material of the ventilating sole element, the laser shots may result in a diameter of the openings in the side wall of the ventilating sole element which equals the diameter of the passages made by the pins in the surrounding sole element during injection. In order to get the desired diameter the number of cycles can be varied as can the relative position of the shots. During a shot cycle the target can be moved a few millimeters (e.g., the robot moves), and the diameter will increase. In a further step, the robot moves the sole to the next target spot, i.e. the process goes to the second step (2) above.
In relation to the ventilating sole element, the opening of the side wall of the ventilating sole element with laser leaves no debris. Everything is burned away. Hereby any clogging of the air channels caused during manufacturing of the openings is prevented. The method further has the advantage that it is very fast compared to drilling out the openings.
In the present example, the diameter of the opening 55 in the wall 602 should be a bit smaller than the diameter of the passages 50 already present in the surrounding sole element; otherwise the laser beam would aesthetically damage the visible edge of the passage.
example, the ventilating sole element is made of a polyurethane based on polyether. The laser beam was applied with 70% power, and the number of cycles was 5. A 2 mm diameter opening was made in the wall of the ventilating sole element. No damage of the walls or side of the midsole occurred.
| Number | Date | Country | Kind |
|---|---|---|---|
| PCT/EP2010/062976 | Sep 2010 | EP | regional |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP11/60036 | 6/16/2011 | WO | 00 | 5/29/2013 |
