WO2018092011A1

WO2018092011A1 - Method and printer for large scale production of customized footwear

Info

Publication number: WO2018092011A1
Application number: PCT/IB2017/057064
Authority: WO
Inventors: Rosalia FILIPPONE
Original assignee: Tradinnovazione S.R.L.
Priority date: 2016-11-15
Filing date: 2017-11-13
Publication date: 2018-05-24
Also published as: EP3541607A1; IT201600115360A1

Abstract

A method is described for making customized footwear, comprising the steps of acquiring at least one image of a foot of a user; making a three- dimensional model of the foot, constructed from said image; acquiring at least one image of a shoe selected by the client; acquiring standard sizes of the lasts provided for making the selected shoe; recognizing the standard size of the last closest to the features of the client's foot according to the three-dimensional model of the foot constructed; modifying the standard size of the closest last in order to obtain a "customized last" of the user's foot; producing, by means of 3D printer, at least one "customized last" for making the shoe; making the shoe according to said "customized last".

Description

"Method and printer for large scale production of customized footwear"

* * * *

The present invention relates to a method and a printer for large scale production of customized footwear.

Making footwear begins with the drawing of a stylist who creates a new model and designs the details of the new shoe. The second step is the one of integrating the stylist with a designer who should combine the ideas of the stylist with the practical application, that is the production of footwear. This means that a die is to be made, that is the so-called "last" about which the shoe is then constructed. Generally, all footwear are manufactured due to predesigned standard lasts which may be adapted to the majority of the population.

The footwear market therefore has a low level of customization. Only over the last years have certain companies started a true production of customized footwear, but in most cases, these involve small adjustments and modifications made on standard lasts; it is unlikely for a new last to be made for each client.

The customized service is also very limited in the luxury field, it relates to niche craft products, for the most part classic men's products, and uses traditional manual measuring methods and requires the physical presence of the client at a store; the lasts used are standard and are adapted to the client's foot with manual adjustments. With regards to women's footwear, the customized product follows the above method and traditionally meets the needs of comfort, with classic lines and moderate heights, generally not exceeding 50 mm.

For example, US 6741728 describes a method for selecting the shoe the most suitable for the client's foot. Said method provides acquiring a 3D image of the foot through photos taken at various angles. The system provides the creation of a 3D reference image on the device to help correctly frame the foot. JP05791812B2 describes a method for acquiring an image of the foot to assess the wearability of a shoe. The method provides acquiring several images of the foot through an acquisition assistance unit which allows a correct positioning of the foot during the photography.

Disadvantageously, said methods allow only images without particular inclinations of the foot to be acquired.

Moreover, there is no true customization of the shoe; indeed for reasons of costs, time and rejects, customized lasts are not manufactured, rather they are only adapted to standard lasts.

Technology and customized product meet in the medical/orthopedic/health field for making/providing orthopedic insoles, shoes and services.

Digital technologies are used by large companies in the sports field for designing soles for performing and competitive footwear. Recently, some of these companies have started making more commercial sports footwear components or parts, in any case we are talking about standardized industrial products and not customized shoes.

Said digital technologies provide using scans of the foot and making lasts by means of 3D printers.

EP1592558B 1 describes a 3D printer capable of simultaneously printing several layers of various materials of an object. Said 3D printer comprises several printer heads which move along a predefined surface.

Disadvantageously, said 3D printer prints with a method which provides depositing multiple layers over one another to define the object to be printed. For example, more than 14 hours with more than 2200 layers deposited which height cannot exceed 0.1-0.3 mm to obtain a good print, are required to print a structure that requires a use of 175 g of printer filament.

Another disadvantage is given by the fact that the print of any object requires a thickness of the walls and of the inner part defined by the print density, otherwise the external walls collapse and the print is not successful. The inner density is given by a mesh formed by overlapping, layer by layer, thread over thread, and may be more or less dense, with subsequent impact on the process times.

If an object with low density is printed to speed up the process, the external walls collapse or the object does not have the consistency required for the final use.

A further disadvantage lies in the fact that the 3D printer consists of several operating units of the same type which form a production line in which the individual units simultaneously perform the same operation to simultaneously produce, each in its own printing area, parts of a same object or of various objects, also using different materials.

WO 2015/171312 discloses a method for making three-dimensional structures for the permanent fastening to a base component, by means of a 3D printer. This base component is always required and may be depicted by various types of objects, for example an upper for shoes, a T-shirt or a shoe. Said printer provides a single extrusion head mounting two nozzles. A first nozzle provides making of the shell of the structure, a second nozzle is adapted to fill the cavity defined by the shell.

US 2010/0106061 describes a method for acquiring the image of a foot by means of an material means/external object with a plurality of supports at various heights to make a shoe with the heel.

It is a first object of the invention to obtain a method for making lasts for constructing customized footwear on a large scale, which allows the industrialization of the production process of the customized footwear by expanding the group of users of such goods/services with a savings in terms of time, reject materials and energy used.

It is a second object of the present invention for the aforesaid method to allow the acquisition of images of a foot through an instrument which is easy to use by people who do not have particular technical skills, by helping with the correct positioning of the foot during the acquisition of the images for making the footwear with various types of heels.

According to the invention, such objects are achieved with a method as described in claim 1.

It is a third object of the present invention therefore to obtain a 3D printer which allows the production of customized lasts to be industrialized with a savings in terms of time, production costs and rejects in the production of footwear lasts.

According to the invention, such an object is achieved with a 3D printer as described in claim 4.

Advantageously, an automatic three-dimensional modeling system of customized footwear lasts may be made through a system of algorithms which cross references the data of the client's feet with the three- dimensional data of the one which we call "master last" corresponding to the model of shoe purchased by the client.

These and other features of the present invention will become more apparent from the following detailed description of a practical example embodiment thereof, shown by way of non-limitative example in the accompanying drawings, in which:

Figure 1 shows a perspective view of a 3D printer;

Figure 2 shows a front view of the 3D printer;

Figure 3 shows a top plan view of the 3D printer.

After several experiments, the Applicant has obtained a method for making customized footwear comprising making footwear lasts with a 3D printer 1.

As shown in figure 1, said printer 1 comprises at least two extrusion heads 2 and 3 on which there is at least one nozzle, arranged laterally with respect to a printing area 4. Said extrusion heads 2 and 3 are connected to a support structure 10 through support arms 11.

Each extrusion head is formed by a body 30 and by a nozzle 300. At least one nozzle 300 may have a heating function. Said support structure 10 comprises at least one work area, a first stop area 101 and a second stop area 102. The work area comprises vertical support elements 105 and horizontal support elements 104. The printing area 4 is between the two stop areas 101 and 102.

At least one pair of suspension elastics 17 connects each arm 11 to the extrusion heads 2 and 3. Said support arms 11 are connected to horizontal sliding tracks 12 by means of sliding blocks 16. Said sliding blocks 16 are adapted to move along the horizontal tracks 12 which extend for the whole length of support 10. Once they have reached the printing area 4, the sliding blocks 16 are adapted to slide in vertical sliding tracks 14 which extend for the whole height of support 10. Thereby, the extrusion heads 2 and 3 are adapted to move horizontally to reach the printing area 4 and to move in a vertical manner within the printing area 4. The extrusion heads 2, 3 are therefore adapted to move along the axes X, Y and Z.

The extrusion heads 2, 3 define two separate printing elements and mount at least one nozzle each, which diameter may be different and variable.

The first extrusion head 2 is movable in space independently from the second extrusion head 3 being supported by different support arms 11.

The two extrusion heads 2, 3 define two separate printing elements which are independently movable in space.

Advantageously, the extrusion heads 2, 3 may operate simultaneously in the same printing area 4 or in at least one other printing area, external to the part depicted in the attachments, thus realizing different portions of different "footwear lasts" with a significant savings in time.

It is worth noting that "shoe last" means the solid object (volume) that replicates the volume (shape) of a foot adapted to be inserted into a shoe. Each user has a "typical" last of his/her foot which the present method intends making to allow quickly and efficiently making a customized shoe.

The movement of the sliding blocks 16 may be actuated mechanically by means of the use of hydraulic fluid, or electrically through the use of electric motors.

At least one element for supplying the extrusion heads with printing material is above the extrusion heads 2 and 3, above support 10, for example a tank 6, (preferably) conical in shape with a portion 61 arranged upwards. A narrowing 62 of tank 6 is positioned towards the bottom and provides an opening 63. A connection tube 13 adapted to connect tank 6 with at least one of the extrusion heads 2 and 3 is inserted in said opening 63. Said tank 6 may contain liquid material or material with various densities or again, solid filling material.

Inside tank 6, there may be accommodated one or more devices, for example magnetic and electric devices for increasing or decreasing the internal and external temperature of tank 6; moreover, there may be one or more sensors for detecting and controlling parameters, for example of the temperature inside and outside tank 6. Inside tank 6, there may be a tool or device for mixing the material arranged therein.

Said tank 6 is adapted to fill the extrusion heads 2 and 3 with the material contained. Said tank 6 preferably contains filling material.

A bobbin 5, preferably circular in shape and adapted to contain a rolled filament 17 of plastic or metal material, is positioned on a same surface as tank 6. Said filament 17 is adapted to supply the extrusion heads 2 and 3.

With regards to the operation, printer 1 may receive pieces of information from at least one software installed on an electronic device; said pieces of information contain the coordinates adapted to allow the correct operation of printer 1 and the movements, the temperature of nozzle 300, the quantity of material and the layers of material which the nozzles of the extrusion heads 2 and 3 must deposit in the printing area 4 to obtain the object desired, for example a shoe last.

The printing process provides for the two extrusion heads 2 and 3, both connected to a single software item or to several integrated software items, to perform at least two different operations and/or alternating steps, that is:

a first step of printing the "shell", that is the outer structure of the last, with printing technique which provides one of the extrusion heads 2 and 3 depositing layer over layer, thread over thread, of printing material, up to reaching a collapsing end point of the shell; once this collapsing end point is reached, one of the two extrusion heads 2 and 3 stops and returns to one of the stop areas 101 and 102; collapsing end point means a point in which a wall of the shell tends to collapse on itself due to the weight thereof; the identification of the collapsing point is predicted by simulation and analysis tools of the printing process in consideration of the conditions and materials provided in the process itself; once this end point is reached, the software interrupts this first printing step and goes to

a second filling step which provides for one of the two extrusion heads 2 and 3 to deposit filling material, by means of nozzle 300, by pouring it into the shell printed in the first step; there may be provided, inside the printing area 4, at least one device or sensor for detecting printing parameters and the environmental conditions and any other useful piece of information for monitoring, predicting, performing simulations and checking the progress of the printing process and the actions to be implemented to manage and resolve any problems due to the integration of artificial intelligence systems in the software; for example, they allow the step of pouring the filling material into the shell to be monitored and managed with automated systems while considering unexpected environmental and/or physical factors which may cause deviations of the "real values" with respect to the "optimal values" set for the printing. The system detects and analyzes the value deviation data and each time is capable of assessing if said deviations are suitable for compromising the outcome of the printing process; if they are, the system intervenes with actions suitable for re-establishing the "optimal values" of the parameters involved; by mere way of non-limiting example, considering the outdoor temperature as unexpected environmental factor which could cause "unexpected variations" on the "optimal value" set for the temperature within the printing area; assuming that from the analysis of the data, the system assesses the deviation as "suitable for altering" for example, the "optimal values" of the expected physical status provided for the printing material, it intervenes by modifying for example, the temperature inside the tank or printing area in order to ensure the normalization of the parameters and the positive results of the printing process. Once pouring of the filling material is complete, the extrusion head 2 or 3 returns to one of the stop areas 101 and 102.

There is a continual succession of the two printing steps up to the completion of the last desired.

The described printing method may be associated with various printing techniques, including FDM, FFF, any other additive technology

(involving depositing material) which is compatible with three-dimensional printing.

Printing and/or filling materials are selected from a group comprising photopolymers in the liquid state, paper, laminated metal, plastic, materials made of powder such as polystyrene or nylon (pure or combined with glass or carbon fibers), metals, including steel, titanium and various alloys, compounds and sandstone powders, metal powders, atomized metals, titanium alloys and chrome cobalt, mixtures of thermoplastic polymers and of thermoplastic polymers with organic materials of other kind, polycarbonate, polyvinyl alcohol, polyethylene terephthalate, high impact polystyrene, nylon, laybrick, laywood, ninjaFlex, and other materials compatible with 3D printers.

At least one of the extrusion heads 2 and 3 may receive the material from bobbin 5 in the shape of filament 17, which passes through body 30 of the extrusion head 2, 3, is heated in specific combustion chamber and is transferred to nozzle 300, and is deposited in the printing area 4.

At least one of the extrusion heads 2 and 3 also receives material from tank 6, which crosses a tube 13, passes through body 30 of one of the extrusion heads 2 and 3 and, by means of nozzle 300, is deposited in the printing area 4.

In certain versions, the machine may have one or more extrusion heads positioned on one or more automatic units or mechanical or robotic arms with the possibility of serving several printing areas, over several simultaneous printing processes coordinated by artificial intelligence systems capable of managing the process in order to optimize times and resources.

The materials of bobbin 5 and of tank 6 may be different from one another or they may be the same material with different density.

Moreover, both the extrusion heads 2 and 3 may receive the same printing material or they may receive various printing materials. Both extrusion heads 2 and 3 may receive the material from a same bobbin, or from two different bobbins, or again from a single tank 6 or from two different tanks 6.

Moreover, one last alone, or two different lasts simultaneously, may be made in the same printing area; indeed the extrusion heads 2 and 3 may move independently and receive different pieces of information from the software.

The extrusion heads 2 and 3 may also process at alternating steps; while one is in the printing area 4, the other one remains in one of the two stop areas 101 and 102.

In a first embodiment (as shown in figure 1), the extrusion head 2 is supplied by bobbin 5 and is assigned to deposit the printing material in the printing area 4, that is to print the shell of the last. The extrusion head 3 is supplied by tank 6 and is assigned to pour the filling material into the shell.

Indeed, the software may send pieces of information for making one or more different lasts in the same printing area 4, printer 1 may be loaded with the same printing material, that is filling material or liquid, or having various densities, directly in tank 6, or with plastic or metal material by means of bobbin 5, or again with two different complementary materials.

When at least one last is completed, the extrusion heads 2 and 3 return to their initial positions, leaving the printing area 4.

The footwear lasts made with this printer 1 will have well-defined features, with very small margins of error. The deposit of multiple layers of material by the extrusion heads is indeed quite accurate due to the control software.

The last has thousands of layers of material or of various materials deposited on top of one another to make the form made.

The software may also receive pieces of information acquired by means of a camera or any other device for acquiring images.

The acquisition of photo images may be performed by means of cellular phones, smartphones, PCs, tablets or other electronic equipment.

The acquisition of images may be performed directly by a client who wants to purchase customized footwear.

To acquire the images, an application for formalizing the purchase through a code assigned to the order may be made available to the client.

The purchase of the footwear may occur physically at a direct company store and/or at third-party premises; here, the registration and measuring operations may be performed by company personnel. The purchase may be made on line, at on-line shops and company and/or third- party platforms on which the client views the catalogue.

The client may then select the suitable model from among the footwear models proposed. Once the selection of model to be purchased has been made, the client registers him/herself by entering all personal and purchase data, and makes the payment.

After the payment, the client receives an order code by email and/or SMS, the order code being associated with his/her order, and a link which brings the client back to the company website or website of authorized third parties, from which the client may download the application by entering the order code.

In said first step, among the various options, the client may select the shoe selected, and then all the pieces of information of said shoe are loaded, that is "the footwear last" characterized by the specific style lines, for example the pointed or rounded or square toe, the measuring data such as the height of the heel, heel girth, length, instep, instep girth, toes, etc.

The goal of acquiring images is to have a three-dimensional file which replicates the morphology of the client's foot to design a customized last made by modifying a "master last" using automated three-dimensional modelling digital and software tools which adapt the standard measurements of the master last to the particular needs of the client' s foot according to the features of the foot by making the specific variations on the last to be printed (merely by way of example, the instep, instep girth, length).

Pieces of information are provided adapted to help the correct positioning of the foot. Said pieces of information may be for example a trace, that is a template of a support for the foot or a target displayed on a screen and which indicate to the client the exact position his/her foot should take on during the image acquisition for positive results; the instructions, coordinates and references required to correctly focus the foot are also provided to the device by means of automated transmission systems.

A trace or template for supporting the foot may be predesigned and appear on a screen with augmented reality instruments. Various template images are pre-loaded according to the various footwear and the various heel heights available.

When the foot is framed with a camera, the image of the foot should overlap the preformed trace on the screen so that the heel height desired coincides with the correct inclination of the of the foot.

If the image of the foot and the trace coincide, the application can emit a sound signal or a light signal, or again it may automatically take the picture and acquire an image.

The image is only acquired if the predesigned trace on the screen perfectly matches with the image of the foot and is focused. The application contains multiple traces of feet; a different trace is loaded on the display according to the type of shoe selected and the perspective of the foot.

If devices used are not provided with suitable instruments, a sheet may be provided, for example a paper sheet, to be positioned on the floor to allow the application to have space references to allow a correct parameterization of the images acquired.

Said sheet, or generically an external support surface, may easily be made available to the client, for example in the form of a PDF file sent by email or downloadable from the company site, and preferably provides coded markers (QRcode or target) for rendering the acquisition of the parametric image of the foot. Said markers also help to avoid signal disturbances, help to define the scale of the foot. Said sheet preferably is opaque.

This allows optimal quality scans and accordingly, optimal quality digital data which are easy to process, to be obtained with a limited number of pictures.

Preferably, the pictures are taken by a different person than the one to whom the foot to be photographed belongs.

Once the images have been acquired, the software installed on the device sends them, also automatically, to the company computer system which automatically processes them due to a dedicated program, and reconstructs a three-dimensional model of the foot.

Once the "three-dimensional model of the client's foot" is reconstructed, it is then also automatically input into another "automatic modeling system" of his/her "customized footwear last".

Said "automatic modeling system" of the customized footwear last provides the various types of "master lasts" used to make the footwear models in the catalog for the public, to be loaded therein each time in three- dimensional digital format. Said digital formats of master lasts are entered with the development of the sizes provided.

Once said system also automatically identifies the last which is to be used for making the model purchased by the client, it cross references the data of the "three-dimensional model of the client's foot" with the ones of the "corresponding master last", thus extracting the standard size which is the closest to the reference measurements of the client's foot.

Then, with a series of algorithm calculations set according to modeling techniques for footwear lasts, the system modifies the "master last", thus adapting the volume and the reference measurements according to the morphological features of the client's foot.

The file is translated into machine language and is sent to the 3D printer which proceeds with making the last or lasts required to make the shoe model purchase by the client.

The order code is associated with a unique order being processed and as such, cannot be used for new scans.

The order code can be used by the client to monitor the progress of the order up to the delivery, to view the catalog and to provide all the after-sales services made available by the company.

The application in any case may be activated by the client for future purchases and scans by entering the new order code. The client's data and the "customized" components are stored in the company files for future purchases.

If successive purchases concern items with the same features of heel height of a previous one, new scans will not be required but it in any case is possible and is recommended by the company itself; a new scan will be required in certain cases in the event the subsequent purchase concerns items with different heights than the preceding ones.

Advantageously, printer 1 is a machine which is easy to actuate, has low energy consumption, which allows unique and performing accurate processing, with savings of times, costs, for a large scale production of customized footwear.

Said printer 1 also allows printing and filling operations to be performed in the same process, thus ensuring a significant savings of time; indeed the printing times of said 3D printer are reduced by 80% with respect to the times of a standard printer, thus allowing the industrialization of the production process of customized footwear.

Another advantage is given by the fact that a client may order customized footwear without the need to go to a store, by directly sending images from a device, thus conveniently allowing access to the customized footwear market by a broad range of consumers.

A further advantage is given by the fact that the client has available a professional, easy-to-use measuring instrument which provides support in scanning the foot due to the presence of automatisms and virtual images which provide a trace for the correct positioning of the foot.

The data of the client's feet are acquired by the system with the three- dimensional model reconstructed according to the measuring method described above.

The three-dimensional data of the master last are entered into the system with the three-dimensional model resulting from the design of the last in the collection.

Said digital format of the master last is developed throughout the whole series of "standard sizes" provided for that specific model and type of shoe.

The system of algorithms cross references the data acquired, recognizes the "master last corresponding" to the standard size which is the closest to the features of the client's foot (for example by length), according to "significant data".

Once said "master last" closest to the client's foot is identified, said system executes the operations required to modify the "master last" in order to obtain a "customized last" of the client's foot.

Said system is programmed with a series of algorithms to execute the calculations according to the rules of "modeling technique of footwear lasts" for making a customized last, rules according to the best shoemaking technique, and the features of the client' s foot.

Said operations relate to an automatic method and to all the operations required to modify a "standard master last" according to the features of the feet of a specific client in order to obtain a pair of "customized lasts" of a specific last according to the best modeling technique of footwear lasts.

Said method is very advantageous for example, if one would like to purchase a shoe while reducing or increasing the height of the heel.

Claims

1. A method for making customized footwear, characterized in that it comprises the steps of

acquiring at least one image of a foot of a user;

making a three-dimensional model of the foot, constructed from said image;

acquiring at least one image of a shoe selected by the user;

acquiring standard sizes of the lasts provided for making the selected shoe;

recognizing the standard size of the last closest to the features of the user's foot according to the constructed three-dimensional model of the foot;

modifying the standard size of the closest last in order to obtain a "customized last" of the user's foot;

producing, by means of 3D printer, at least one "customized last" for making the shoe;

making the shoe according to said "customized last".

2. A method according to claim 1, characterized in that the acquisition of at least one image of a foot occurs by means of an electronic device, due to a trace in augmented reality on a screen adapted to allow the correct inclination of the foot according to the type of shoe selected by a client and according to the height of a heel selected, the acquisition providing the use of a flat external support provided with coded markers.

3. A method according to claim 2, characterized in that said flat external support is an opaque sheet.

4. A 3D printer (1) for producing a customized "footwear last", comprising at least two extrusion heads (2, 3) with at least one nozzle (300), at least one tank (6) containing filling material and at least one bobbin (5) with printing material, wherein a first extrusion head (2) is supplied by the bobbin (5) and is adapted to deposit print material for making a shell, and a second extrusion head (3) is supplied by the tank (6) and is adapted to pour filling material into said shell,

characterized in that

the first extrusion head (2) is movable in space independently from the second extrusion head (3), said extrusion heads (2, 3) being supported by different support arms (11) connected to respective sliding blocks (16) sliding on tracks (17) of the 3D printer (1),

said 3D printer (1) providing a support structure (10) adapted to identify separate stop areas (101, 102) for respective extrusion heads (2, 3), and at least one common printing area (4) wherein said extrusion heads (2, 3) may operate simultaneously or independently.

5. A 3D printer (1) according to claim 4, characterized in that at least one pair of suspension elastics (17) connects each support arm (11) to the respective extrusion head (2, 3).

6. A 3D printer (1) according to claim 4 or 5, characterized in that devices for increasing or decreasing the temperature of the tank (6) are accommodated inside the tank (6).

7. A 3D printer (1) according to claim 6, characterized in that it comprises means suitable for detecting deviations of "true print values" with respect to "optimal print values".