Patent Application
20240324728
The present invention relates to a last for footwear manufacturing and a method for manufacturing a footwear.
The manufacturing of footwear is often a mass production process still involving manually performed tasks by footwear manufacturers.
This is especially the case in relation to a manufacturing process where the footwear upper is put on a last for the manufacturing of a sole e.g. by direct injection molding, where a molten material is injected into a mould and the molten material expands inside the mould in order so that the cured molten material provides a sole assembly which is bonded to the upper.
Thus, there is a need for cheaper and more flexible alternatives for footwear manufacturing, e.g. where the manual tasks such as in relation to lasting may be facilitated and/or made easier to perform.
In the prior, art examples of lasts have been disclosed, wherein a heel body part may be movable in order to ease the lasting of an upper. Such an example is disclosed in DE 10319593 A1, wherein a heel body part is configured to be moved a distance down along a curved path, whereby the lower part of the heel body part is below the lower part of the last body and slightly towards a forefoot of the last. By this prior art last the positioning of the upper may be facilitated, as the distance from toe to heel of the last is slightly reduced, when the heel body part has been moved.
Further, U.S. Pat. No. 3,203,050 A discloses a shoe last for manual manufacture of soles upon uppers, where the last has a last block, a pivotal toe block that is hinged to the last block by a hinge and a heel block that is movably connected to the last block. The movement of the toe block and the heel block is effected with a leverage mechanism comprising a lever that via a link can move the heel block along a path and where the heel block and the toe block are connected with a further link. Thus, with the last positioned upside down, a movement of the lever upwards, from a closed position to an opened position, will effect that the heel block slides upwards and closer to the toe end, while the toe block pivots downwards and vice versa. Thus, the movement of the lever upwards will effect a pivoting movement of the heel block and the toe block in the same direction.
Even further, U.S. Pat. No. 1,071,901 A relates to a collapsible last having a heel part, a fore part and an instep block. The heel part comprises a socket for supporting the last and the instep block is connected to the two other blocks via a hinge strip, a link and respective pins. The instep block may, when a plunger is released, be slid up and the toe or heel may be raised to shorten the last longitudinally.
The invention relates to a last for footwear production, wherein the last comprises:
The inventive last has several advantages over prior art involving an efficient lasting- and delasting process by moving and opening of the front body part and the heel body part that improves the fitting of the upper to the last.
Hereby, the manufacturing of e.g. boots and slip-ons, that during conventionally lasting and delasting may be manually challenging and time consuming especially in relation to minimise or avoid wrinkles of the upper materiel on the upper front or vamp on the forefoot, may be improved.
Thus, in addition to providing a more efficient production process due to saving of manual labour time, improvements in the finished product may be achieved, e.g. due to better fitting of the upper of the footwear.
By having said heel body part and/or said forefoot body part being configured to be movable in relation to the last body by at least one coupling arrangement, numerous configurations may be achievable, whereby the heel body part and/or the forefoot body part may be moved, e.g. including that both may be moved simultaneously, whereby the last may quickly and easily be brought to a lasting mode and subsequently brought to a mode, wherein a footwear upper has been lasted, ready to take part in the subsequent footwear production process, possibly after some minor manual adjustment.
Further, by the coupling arrangement, a wide variety of applications are possible, e.g. with the heel body part being moved first, followed by the forefoot body part being moved next or vice versa. Also, it is a possibility that the heel body part may be moved a relatively small angle, which is transferred to the forefoot body part as a relatively large angle or vice versa.
Further options will be available, depending on the actual configuration of the coupling arrangement.
In an embodiment of the invention, the last comprises an open position and an operational position.
It is noted that the open position denotes the position, wherein a footwear upper may be arranged on the last, and that the operational position denotes the position, wherein the last, which now may carry the upper, has both movable parts positioned such that the last essentially has the form corresponding to a human foot.
The last may open by applying upwards force on the heel body part, which will also cause the front part to open, e.g. due to the action of the coupling arrangement. Hereby, both the front body part and heel body part may be in an open position at the same time. Thus, lasting and delasting of a footwear upper on a last is made easier to handle and an easier manual operation may be effected.
In an embodiment of the invention, the heel body part may in said open position of the last have been moved at least partly towards a toe end of the last and said forefoot body part may have been moved at least partly towards a heel end of the last.
Hereby, the movement of both the heel body part and the forefoot body part will contribute in reducing the distance between e.g. heel and toe of the last, since both parts will move towards each other in the longitudinal direction of the last, while possibly also moving in a vertical direction as well, e.g. along a curved path, e.g. from an outer boundary towards a centre of the last/last body.
Thus, an increased distance reduction, e.g. reduction of the longitudinal direction of the last can be achieved, for example when comparing the inventive last with the last as disclosed in U.S. Pat. No. 3,203,050 A, where, when opening the last (in an upside-down position), the heel block slides upwards and closer to the toe end, but where at the same time the toe block pivots downwards and moves away from the last block.
In an embodiment of the invention, the last further comprises a lower surface, wherein the lower surface has a toe end and a heel end, wherein the lower surface has a length TL between the toe end and the heel end, and wherein the length TL2 of the lower surface in open position is shorter than the length TL of the lower surface in operational position.
In an embodiment of the invention, the length TL2 of the lower surface in open position is between 2-10%, such as between 4-8%, such as between 5-7% shorter than the length TL of the lower surface in operational position.
In an embodiment of the invention, the length TL2 of the lower surface in open position is at least 4% shorter than the length TL of the lower surface in operational position.
In an embodiment of the invention, said forefoot body part in an open position of the last is inclined by an angle (a) in relation to said lower surface, wherein said angle is at least 5°.
In an embodiment of the invention, said angle (a) formed by said forefoot body part in relation to said lower surface is at least 10°, such as at least 15°, such as at least 200 or such as at least 25°.
In an embodiment of the invention, said forefoot body part has a length TLF from the toe end and in a direction along the lower surface, which is at least 10%, alternatively at least 20% or alternatively at least 30% of the length of the lower surface in operational position.
In an embodiment of the invention, said last has a girth measurement at a high instep position D that in an open position is less than or equal to the girth measurement at the high instep position D in closed position of the last.
Hereby, it is achieved that the volume of the last at the D point has not been increased when moving from closed, e.g. operational position, to open position as is the case in connection with a prior art last with only a movable heel body. Thus, compared with this prior art last, it may be achieved that a lasting of an upper on a last may be made with less effort and with gentler treatment of the upper.
In an embodiment of the invention, said last has a girth measurement from back of heel to instep H that in an open position is less than the girth measurement from back of heel to instep H in closed position, e.g. operational position, of the last.
Hereby, it is achieved that the volume of the last at the H point has been reduced when moving from closed, e.g. operational position, to open position. It may thus be achieved that a lasting of an upper on a last according to this embodiment may be made with less effort and with gentler treatment of the upper.
In an embodiment of the invention, the coupling arrangement is made of metal, e.g. steel.
In an embodiment of the invention, the coupling arrangement comprises a linked bar mechanism.
In an embodiment of the invention, the coupling arrangement comprises a heel bar and a forefoot bar, which are each pivotably attached to the last body at an intermediate position and mutually linked at one end of the heel bar and the forefoot bar, respectively, and where the other end of the heel bar and the forefoot bar, respectively, is linked to the heel body part and the forefoot body part, respectively.
In an embodiment of the invention, the coupling arrangement is held together by pins for rotation.
In an embodiment of the invention, said forefoot bar is arranged in an open position of the last to be inclined in an angle (b) in relation to said lower surface, wherein said angle is at least 10°, such as least 20°, such as at least 30°, such as at least 400 or such as at least 45°.
In an embodiment of the invention, the last is configured for ballerina, pumps, slip-on shoes and/or boots.
In an embodiment of the invention, said last is configured for independent movement of said forefoot body part.
Hereby, it may be possible to manually move said forefoot body part, if desired.
In an embodiment of the invention, said last is configured for independent movement of said heel body part.
Hereby, it may be possible to manually move said heel body part, if desired
In an embodiment of the invention, said last comprises a decoupling arrangement for decoupling movements of said heel body part and said forefoot body part.
In an embodiment of the invention, said decoupling arrangement for decoupling movements of said heel body part and said forefoot body part is at least partly integrated with said coupling arrangement.
The invention further relates to a method for manufacturing a footwear, comprising the steps of
In an embodiment of the invention, said method comprises the step of
In an embodiment of the invention, said method comprises the step of
In an embodiment of the invention, said activation and/or said deactivation of the at least one coupling arrangement is mediated via operation of an operator rod.
In an embodiment of the invention, said activation and/or said deactivation of the at least one coupling arrangement, mediated via said operation of a said operator rod, comprises moving said heel body part by said operator rod.
In an embodiment of the invention, the method further comprises applying a footwear sole to the footwear upper.
In an embodiment of the invention, the method comprises applying a sole to the upper by direct injection process.
In an embodiment of the invention, the direct injection process comprises direct injection process material.
In an embodiment of the invention, the direct injection process material is TPR, PVC, EVA, TPU and/or PU.
In an embodiment of the invention, the direct injection material is PU.
In an embodiment of the invention, the sole comprises TPR, PVC, EVA, TPU and/or PU.
In an embodiment of the invention, the footwear upper comprises leather.
In an embodiment of the invention, the footwear upper comprises textile.
The last body according to embodiments of the invention, may be manufactured from a polymeric material or a material comprising a polymer. The polymeric material of the last body may have a hardness that allows the last body to resist indentation during the use of the last body. The last body may comprise a polymeric material having a Shore D value of between 50 and 100 and the polymeric material of the last may be constructed of a polymeric composition comprising a polymeric material having reinforcement materials such as e.g. carbon fibers, glass fibers or other types of material that may reinforce the last body.
The last body may comprise a thermoset material such as a thermoset polymer and the last may be produced by providing a polymeric material or a molten material in a molten state where the curing or hardening of the material ensures that the material maintains its shape after the material has cured. Further, the last body may comprise photocurable polymers and/or resin material causing the polymers and/or resin to solidify. The thermoset polymer may be irreversible hardened by curing from a solid or viscous liquid prepolymer or resin. Curing may be induced by heat or suitable radiation and may be promoted by high pressure or mixing with a catalyst.
The last body may also comprise at least one support structure extending in the internal of the last e.g. from an internal surface of the last body to an opposing internal surface of the last body. The support structure may be positioned in such a way that a certain area of the last body may be reinforced to prevent damage to the last body. A support structure may be in the form of a girder, crossbar, brace or any type of rigid and/or semi rigid structure which is capable of transferring force from one region of the inner surface of the last body to another region of the inner surface of the last body. The side walls of the last body and/or the last body may be formed by additive manufacturing. The additive manufacturing may be a process where a material is joined or solidified under computer control to create the last body where material is added together layer by layer or where liquid molecules or powder grains are being fused together or where a layer of material is added on top of another layer of material in a sequence. The additive manufacturing may be done by 3D printing the last for footwear production and/or the last body and/or any part of the last that can be manufactured along with the last body. Additive manufacturing materials may comprise polymers, resin photopolymers, ABS, PLA, ASA, nylon/nylon powder, PETG, metal/metal powder, plaster powder, HIPS, PET, PEEK, PVA, ULTEM, polyjet resin and/or ceramics and any combination thereof.
Similar applies as regards parts of the last, e.g. a heel body part, a forefoot body part, etc.
The footwear according to embodiments of the invention, may be any type of footwear such as e.g. a sneaker, sport's shoe, formal shoe, boot, lace up shoe, slip-on, ballerina, pump, loafer, sandal or any other type of footwear.
The upper according to embodiments of the invention, may be of any material such as e.g. leather, natural leather, textile, reinforcing fabric, reconstructed fibers, woven or non-woven material based on natural or synthetic fibers or any other type of material.
Leather may be any type of leather such as e.g. full grain or top leather, corrected or embossed grain, split suede, nubuck sueded grain, reconstructed, reconstituted, bonded or fiber leather or any other type of leather. In principle, the leather can derive from any source, including bovine hide, horse hide, goat skin, sheep skin, camel skin, kangaroo hide or the like.
“Bovine” as used herein means, with referral to the traditional taxonomic grouping, a group of animals including e.g. cattle, ox, yak etc.
The term “staple fiber” refers to fibers of discrete length and may be of any composition. Staple fiber may e.g. be provided by division of a keratin-based filament into discrete staple fibers of a certain length. The length may vary dependent on the application.
The term “reconstructed” fiber refers to staple fibers produced on the basis of a number of mechanically sub-divided protein fibrils. The reconstructed fiber may be formed from a protein suspension directed through a nozzle onto a surface for drying. The suspension is dried to remove water and solvent from the suspension and thereby the reconstrued fiber is formed e.g. on a belt or a cylinder surface. Such a manufacturing method of reconstructing fibers on the basis of protein fibrils is e.g. illustrated in WO 2018/149950 or WO 2018/149949 for the use in relation to collagen.
“Reinforcing” as used herein should be understood as a reinforcing fabric comprising high strength fiber that can be woven or nonwoven. To benefit from the strength properties of the fibers, typically at least one layer will contain the high strength fibers in an oriented fashion, such as woven (including uniweave), monodirectional or multidirectional fabrics.
Tanning is used as the conventional ways of treating leather and may be applied to the invention. The technical definition of tanning is well known in the art, but briefly, according to Anthony D. Covington “Tanning Chemistry” chapter 10, the only strict definition of tanning is the conversion of a putrescible organic material into a stable material capable of resisting biochemical attack. Tanning involves a number of steps and reactions depending on the initial material and the final product.
Direct injection process should be understood as the process of introducing a molten material into a cavity of a mold to achieve a desired shape. The process can be used for the production of outsole or decorative details. During the process, a molten material, normally a polymer, is forced into the cavity of a mold.
The process may be known as DIP or direct injection process and they may be used interchangeably.
Unless otherwise noted in the present application, the meaning of DIP is to be understood as the process of integrating a sole with an upper or at least a part of an upper by and during a DIP process.
Thus, single elements, e.g. pressure absorbers or sole parts may be DIP'ed in separate processes (without being attached to the sole) and then subsequently be inserted into the mold by means of which the sole or a part of the sole is to be molded and integrated with the upper or at least a part of the upper.
The sole may also be manufactured by a casting process where sole material is added (and not injected via an injection channel) to the mould.
It should be noted that the process of attaching the sole to the upper is not limited to DIP and may also be by a cementing sole process with a pre-made sole adhered to the upper.
It should be noted that the process of attaching the sole to the upper implies that the sole is pre-made. The process may e.g. also be referred to as a cementing within the art.
The sole can be manufactured from any materiel such as e.g. thermoplastic Rubber Injection Molding Resin (TPR), Polyvinyl chloride (PVC), polyurethane (PU), Ethylene Vinyl Acetate (EVA) and/or the like suitable for a direct injection process.
The sole can also comprise several parts possibly manufactured from different materials. Such parts may be molded into the sole or may be attached to the sole by e.g. an adhesive or the like.
The manufacturing process according to embodiments of the invention may be a manual process or may be an at least partly automatic process.
It should be noted that in general when describing embodiments of the invention herein, the last will be positioned in the normally used lasting position, e.g. with the sole facing surface of the last facing in general upwards and thus directions mentioned, e.g. upwards, downwards, etc. may be understood in view of such a position, for example as regards moving the heel body part and/or the forefoot body part upwards and/or downwards.
Various exemplary embodiments and details are described hereinafter with reference to the figures when relevant. It should be noted that the figures may or may not be drawn to scale and the figures are only intended to facilitate the description of the embodiments.
The invention will be explained in further detail below with reference to the figures of which
With reference to
A footbed in the present context, unless otherwise noted, may thus e.g. include both insole (if present), different sole members and/or layers. In particular embodiments of the invention further layers or members may be attached to the footbed or the layers may be included within the footbed. Hereby, several variations of the order of the material of the footbed are possible either as a single material or as sandwich constructions of materials.
With reference to
An embodiment of a last 10 according to the invention for footwear production is illustrated in
In
In
Even further, the heel bar 42 and the forefoot bar 44 are at their other ends designed for being connected with the heel body part 18 and the forefoot body part 20, respectively. Thus, the heel bar 42 is configured with a heel bar slot 56, which cooperates with a heel body pin 52 that is fixed to the heel body part 18. In a corresponding manner, the forefoot bar 44 is configured with a forefoot bar slot 58, which cooperates with a forefoot body pin 54 that is fixed to the forefoot body part 20. Thus, in case the heel body part 18 is moved upwards in the scenario shown in
The heel bar 42 and the forefoot bar 44 are furthermore shown in
It should be noted that this linked bar mechanism 40 may be configured in various manners in order to achieve specific movements of the heel body part 18 and the forefoot body part 20. For example, the length of the heel bar 42 and the forefoot bar 44 may be varied and the position of the pin bores of each of the heel bar 42 and the forefoot bar 44 may be varied, e.g. to achieve different lengths of the bar arms from the pivot point (last body pin 46) meeting each other at the linkage pin 48. Thus, a “gearing” of the movements may be achieved, e.g. with a relatively small angular movement of the heel bar 42 resulting in a relatively large angular movement of the forefoot bar 44 and thus also the forefoot body part 20 or vice versa. Also, it will be understood that the arrangement may be such that the heel bar 42 and the forefoot bar 44 may move essentially identical angles.
It should be noted that other linkages or mechanisms than a linked bar mechanism may be utilized for transforming movement between the heel body part and the forefoot body part. For example, toothed mechanisms may be used, mechanisms using gear wheel or gear segments, where e.g. a gear segment is coupled to an axle with an operating arm or coupled directly to an operating arm may be utilized. When using such mechanisms, gearings between the movements of the heel body part and the forefoot body part may be arranged, similar to what was explained above in connection with the linked bar mechanism 40.
Other mechanisms may be arranged for performing the function of the coupling arrangement 22, e.g. moving the heel body part 18 and the forefoot body part 20 simultaneously or possibly staggered, when one of these is being moved upwards and subsequently downwards again, for example actuated by an operator rod.
It is noted that the heel body part 18 and the forefoot body part 20 may be further guided in relation to the last body 16, e.g. by guiding structures 60 on the last body and corresponding guiding structures arranged in connection with heel body part 18 and the forefoot body part 20, which serve to guide the parts in a desired manner to achieve the function that the heel body part 18 and the forefoot body part 20 move upwards (as seen when the last is positioned as shown in e.g.
It is further noted that the linkage mechanisms, pins, gears, etc. and other parts used in connection with the coupling arrangement 22 due to the strain and wear induced may be made from metal, e.g. steel. However, other materials may be used instead, such as synthetic materials, polymers, etc.
As regards parts such as the last body 16, the heel body part 18 and/or the forefoot body part 20, it is noted that these may be made from metal, e.g. aluminium, but that other materials may be used as well, such as synthetic materials, polymers, 3D printed materials, etc.
Thus,
It will be understood that the heel bar 42 and the forefoot bar 44 may be fixed within the last body 16, e.g. with the last body pins as described above, ready for being coupled to a heel body part and a forefoot body part.
In
According to an example, the distance from toe to heel may have been reduced by around e.g. 3.7%, e.g. the reduction from TL to TL1.
However, when utilizing the last 10 as illustrated in
Furthermore, it is illustrated in
The angle a formed by said forefoot body part 18 in relation to said lower surface 24 may be at least 10°, such as at least 15°, such as at least 20° or such as at least 25°.
Further, it is illustrated that the forefoot bar 44 may in an embodiment be arranged such that in an open position of the last it may be inclined in an angle b in relation to said lower surface 24, wherein said angle is at least 10°, such as least 20°, such as at least 30°, such as at least 40° or such as at least 45°. Hereby, suitable inclination angles a of the forefoot body part 20 may be achieved.
Thus, the D point measurement is the girth at “high instep” of the last and the H point measurement is the girth from back of heel to instep of the last 10 as illustrated in the figures. As it will be understood, these measurements are indicative of the volume of the last at the respective points. The respective measurements may for example be made using e.g. a flexible measuring tape in order to measure the girth at the respective points, along the surface of the last and following the lines as indicated in
It will be clear that the D point measurements and the H point measurements will depend on the modes of the last, e.g. whether the last is in the operational position (closed last) as shown in
In Table 1 below, measurements have been made on a last designed for a US size 4% (European size 37).
As it will be seen, both D point measurements and H point measurements increase, when the heel is opened, e.g. as is the case with the above-mentioned prior art last, thereby indicating that the job of lasting a footwear upper on such a last with opened heel will be more difficult due to the increased girth (or volume) of the last at the D point and the H point.
However, as it furthermore will be seen from the measurements of Table 1, when the heel as well as the forefoot body part have been opened, bringing the last according to the present invention to its open position, the D point measurement will in this position be the same as in the closed position, meaning that the volume at the D point has not been increased. Furthermore, it is noted that H point measurement in the open position has actually been reduced as compared to the closed position, meaning that the volume at the H point has been reduced, which will make it easier to perform a lasting of an upper on a last according to the present invention. All in all, since the D point measurement is not increased and since the H point measurement is reduced as compared with a closed last, it will be understood that the lasting of a footwear upper will be made less complicated and may be made with less effort, e.g. if performed manually. Furthermore, it will be understood that even further advantages may be achieved when compared to the above-mentioned prior art last with movable heel, for which the D point measurement as well as the H point measurement are increased.
Hence, it will be seen that by the invention length reductions as well as volume reductions may be achieved, whereby lasting may be performed easier and with less effort.
As shown in
It will be understood that the heel body part 18 may also be moved independently as indicated by the short dash double-arrow in
As mentioned above, the last 10 may comprise a linked bar mechanism 40, which may be decoupled in case it is desired to move e.g. the forefoot body part 20 manually. A decoupling may be done in various manners, e.g. by disconnecting the heel bar 42 and the forefoot bar 44 (
In the above description, various aspects and embodiments of the invention have been described with reference to the drawings, but it is apparent for a person skilled within the art that the invention can be carried out in an infinite number of ways, using e.g. the examples disclosed in the description in various combinations, and within a wide range of variations within the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| PA 2021 70381 | Jul 2021 | DK | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DK2022/050160 | 7/15/2022 | WO |
