Abstract
A last for footwear production. The last includes a last main body that has an external surface that at least partly has a shape of a human foot, and a movable last body part. The last main body and the movable last body part are at least partly formed by additive manufacturing. The main body and the movable last body part each include guiding structures configured for guiding at least partly a relational movement of the last main body and the movable last body part.
Claims
1. A last for footwear production, the last comprises comprising: a last main body having an external surface that at least partly has a shape of a human foot, and a movable last body part, wherein said last main body and said movable last body part are at least partly formed by additive manufacturing, wherein said last main body and said movable last body part each comprises guiding structures configured for guiding at least partly a relational movement of said last main body and said movable last body part, and wherein said guiding structures of said last main body and said movable last body part are at least partly formed by additive manufacturing.
2.-3. (canceled)
4. The last according to claim 1, wherein said movable last body part comprises a heel body having at least partly the shape of a human heel.
5. The last according to claim 1, wherein said movable last body part comprises a forefoot body having at least partly a shape of a human forefoot.
6. The last according to claim 5, wherein said movable last body part comprises an upper forefoot body having at least partly a shape of an upper human forefoot.
7. The last according to claim 5, wherein said movable last body part comprises a toe body having at least partly the shape of a human toe part.
8. The last according to claim 1, wherein said guiding structures of said last main body and said movable last body part comprise a separate guiding structure (58), configured to be assembled with said last main body or said movable last body part to form at least part of said guiding structures, and wherein said separate guiding structure is at least partly formed by additive manufacturing.
9. (canceled)
10. The last according to claim 1, wherein said last comprises a locking-unlocking mechanism for locking said last main body and said movable last body part in one or more positions of said relational movement of said last main body and said movable last body part.
11. (canceled)
12. The last according to claim 1, wherein the last further comprises an attachment structure configured to attach the last main body to a footwear manufacturing device.
13. The last according to claim 12, wherein the attachment structure is positioned on a top part of the last main body.
14. The last according to claim 12, wherein the attachment structure comprises one or more openings extending in a vertical direction.
15. The last according to claim 1, wherein the last main body has a side wall having said external surface having at least partly said shape of a human foot and an internal surface defining an inner volume of the last main body.
16. The last according to claim 15, wherein the side wall has a thickness between 2 and 10 mm.
17. (canceled)
18. The last according to claim 1, wherein the last main body and the movable last body part at least partly comprise homogeneous material structures.
19. (canceled)
20. The last according to claim 1, wherein the last main body or the movable last body part comprises a polymer.
21. The last according to claim 1, wherein the last main body or the movable last body part comprises a polymeric material having a Shore D value of between 50 and 100.
22. The last according to claim 1, wherein additive manufacturing materials utilized by said additive manufacturing comprises at least one selected from the list of 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.
23. The last according to claim 1, wherein the last main body comprises a cooperating wall and wherein the movable last body part comprises a cooperating wall.
24. The last according to claim 1, wherein the last main body comprises a cooperating wall of the last main body and wherein the movable last body part comprises a cooperating wall of the movable last body part, wherein further the cooperating wall the last main body comprises two supporting wall parts and wherein the cooperating wall comprises two supporting wall parts.
25. The last according to claim 24, wherein at least part of the supporting wall parts is 3D printed, and wherein the area of the 3D printed supporting wall parts is at least 5% of the total area of the supporting wall parts.
26. The last according to claim 24, wherein at least part of the supporting wall parts is 3D printed, and wherein the area of the 3D printed supporting wall parts is between 5% and 50% of the total area of the supporting wall parts.
Description
THE FIGURES
[0083] The invention will be explained in further details below with reference to the figures of which [0084] FIGS. 1a-1c show a last having a movable heel body, seen in perspective views from different angles, [0085] FIGS. 2a-2c show a last having another embodiment of a movable heel body, seen in perspective views from different angles, [0086] FIGS. 3a-3c show a last having a movable upper forefoot body, seen in perspective views from different angles, [0087] FIGS. 4a-4c show a last having a movable toe body, seen in perspective views from different angles, [0088] FIG. 5 shows in a schematic manner a side sectional view of an exemplary last for footwear production, [0089] FIG. 6 corresponds to FIG. 5 and illustrates that the movable last body part may be moved in relation to the last main body, [0090] FIG. 7 corresponds to FIG. 6 but illustrates that the last main body and/or the movable last body part is made as essentially solid structures, [0091] FIG. 8 illustrates schematically various forms of the movable last body part, [0092] FIG. 9 illustrates schematically various forms of a movable last body part at the forefoot part of the last, [0093] FIGS. 10-11 show an embodiment of a movable heel body and the corresponding last main body, [0094] FIGS. 12-14 illustrate schematically various configurations of a guiding structure, [0095] FIGS. 15-16 show various guiding structures seen in a transverse sectional view, [0096] FIGS. 17a-b show in a schematic manner a last main body, assembled with a movable last body part in a sectional view, [0097] FIG. 18 shows an example of a last main body, seen in a perspective view from the side, and [0098] FIG. 19 shows correspondingly a heel body to be assembled with the last main body of FIG. 18.
DETAILED DESCRIPTION
[0099] With reference to FIGS. 1a-c an exemplary last 1 for footwear production in accordance with the present disclosure will be elucidated. The figures show a last 1 having a movable last body part 40, which in this example is a heel body 42, seen in perspective views from different angles, namely FIG. 1a as seen from the side, FIG. 1b as seen askew from the toe end 2 and the lateral side and FIG. 1c as seen askew from the heel end. The last 1, which comprises a toe end, a heel end, a medial side 4 and a lateral side 5, as well as an upper surface and a lower surface will later be explained in further detail, but it is noted that the last 1 comprises a last main body 10 having an external surface 9 that at least partly has the shape of a human foot. Furthermore, the last 1 comprises a movable last body part generally designated 40. In FIGS. 1a-c the movable last body part 40 is in the form of a heel body 42 that as indicated by the double-arrow generally may be moved between two positions. In one of these it unites with the last main body 10 to function as a tool in footwear production, e.g. for supporting a footwear upper while manufacturing a piece of footwear, e.g. during a direct injection production (DIP) process for moulding a sole part on the footwear upper. In the other position the heel body 42 is opened, whereby the effective length between toe end 2 and heel end 3 is reduced, whereby the job of positioning a footwear upper (not shown) on the last 1 is made easier.
[0100] As shown in FIGS. 1a-c, a last holder 15 is attached to the last 1, e.g. the last main body 10 for facilitating attachment of the last to a footwear manufacturing device. In this connection it is noted that operator means (not shown in FIGS. 1a-c) may be arranged in connection with or via the last holder 15 for operating the movable last body part 40 as indicted by the double-arrow.
[0101] It is also noted that as indicated in FIG. 1c, the last main body 10 and the movable last body part, e.g. the heel body 42, may each have cooperating walls, e.g. the cooperating wall 50 of the last main body and the cooperating wall 52 of the movable last body that may e.g. slide along each other when the movable last body is moved in relation to the last main body 10. Thus, guidance and support is provided, but as it will explained in further detail later on, further guiding structures may be provided.
[0102] It is furthermore noted that as shown in FIGS. 1a and 1c, a top part of the heel body 42 is provided with a relatively flat part that in the upper position will meet with an indentation of the last main body 10 to form a natural stop.
[0103] In a similar manner, FIGS. 2a-cillustrate a last 1 having another embodiment of a movable last body part 40, seen in perspective views from different angles. Thus, the figures show a last 1 having a movable last body part 40, which in this example also is a heel body 42, but with a different form than as shown in FIGS. 1a-c. The last 1 is seen in perspective views from different angles, namely FIG. 2a as seen from the side, FIG. 2b as seen askew from the toe end 2 and the lateral side and FIG. 2c as seen askew from the heel end. The heel body 42 as illustrated in FIGS. 2a-c is not formed with an abrupt top part but has a decreasing thickness towards the top. Thus, it will be understood that the heel body 42 will be controlled in its upwards movement by other means, for example operator means (not shown in FIGS. 2a-c) that may be arranged in connection with or via the last holder 15 for operating the movable last body part 40 as indicted by the double-arrow.
[0104] Also, as described in connection with FIG. 1c, the last main body 10 and the movable last body part, e.g. the heel body 42, as shown in FIGS. 2a-c may each have cooperating walls, e.g. the cooperating wall 50 of the last main body and the cooperating wall 52 of the movable last body that may e.g. slide along each other when the movable last body is moved in relation to the last main body 10, e.g. for providing guidance and support.
[0105] Further, as shown in a similar manner in FIGS. 3a-c, a last 1 may have a further embodiment of a movable last body part 40, seen in perspective views from different angles. Thus, the figures show a last 1 having a movable forefoot body 44, which in this example is an upper forefoot body 46. The last 1 is seen in perspective views from different angles, namely FIG. 3a as seen from the side, FIG. 3b as seen askew from the toe end 2 and the lateral side and FIG. 3c as seen askew from the heel end. The upper forefoot body 46 may be moved as indicated with the double-arrow and where the upper forefoot body 46 in its upper position may facilitate an easier lasting of a footwear upper.
[0106] The heel body 42 as illustrated in FIGS. 3a-c is not formed with an abrupt top part but has a decreasing thickness towards the top. Thus, it will be understood that the heel body 42 will be controlled in its upwards movement by other means, for example operator means (not shown in FIGS. 2a-c) that may be arranged in connection with or via the last holder 15 for operating the movable last body part 40 as indicted by the double-arrow.
[0107] Also here, it is noted that the last main body 10 and the movable last body part, e.g. the upper forefoot body 46 as shown in FIG. 3a may each have cooperating walls, e.g. the cooperating wall 50 of the last main body and the cooperating wall 52 of the upper forefoot body 46 that may e.g. slide along each other when the movable last body is moved in relation to the last main body 10, e.g. for providing guidance and support.
[0108] Even further, as shown in a similar manner in FIGS. 4a-c, a last 1 may have a further embodiment of a movable last body part 40, seen in perspective views from different angles. Thus, the figures show a last 1 having a movable toe body 48. The last 1 is seen in perspective views from different angles, namely FIG. 4a as seen from the side, FIG. 4b as seen askew from the toe end 2 and the lateral side and FIG. 4c as seen askew from the heel end. The toe body 48 may be moved as indicated with the double-arrow and where the toe body 48 in its lower position may facilitate an easier lasting of a footwear upper, e.g. due to a reduction of the length from toe to heel and/or due to the inclination of the toe body leading to an easier lasting for certain types of footwear.
[0109] Also as regards this embodiment, it is noted that the last main body 10 and the movable last body part, e.g. the toe body 48 as shown in FIG. 4a may each have cooperating walls, e.g. the cooperating wall 50 of the last main body and the cooperating wall 52 of the toe body 48 that may e.g. slide along each other when the movable last body is moved in relation to the last main body 10, e.g. for providing guidance and support.
[0110] FIG. 5 shows in a schematic manner a side sectional view of an exemplary last 1 for footwear production, which comprises a movable last body part 40, which in this example is a heel body 42. As shown, the last main body 10 and the movable heel body 42 may be divided along a dividing line D. The dividing line D may be rectilinear, curved or take other forms, but for illustrative purposes it has been shown as being linear in FIG. 5. The dividing line D may represent a dividing plane, surface or the like that extends in the transverse direction of the last main body. It is noted that in case the last is designed with an inner volume, at least a dividing wall 8′ may preferably be located at or near the dividing line as indicated in FIG. 5.
[0111] As it appears from FIG. 5, the last 1, e.g. the last main body 10 together with the movable heel body 42 has the shape of a human foot, where the last 1 has a toe end 2, a heel end 3, a medial side 4 (not shown) and a lateral side 5 (not shown), as well as an upper surface 6 and a lower surface 7. The last 1 may at least partially have been made by additive manufacturing, e.g. 3D printing, and may have a side wall 8, where the side wall has an external surface 9 and an inner surface (not shown), where the inner surface defines an inner volume (not shown) of the last 1. The last has a longitudinal axis A, a vertical axis B and a transverse axis C (not shown in FIG. 5).
[0112] As further shown in FIG. 5, the upper surface 6, which may serve the purpose of supporting or being fixed to a last holder 15 (not shown in FIG. 5), and the last main body 10 may for this reason be configured with an attachment structure 17, which may comprise a number, e.g. one, two as shown or even more openings 18, 19 in the top of the last 1, e.g. the top of the last main body 10. This or these openings 18, 19 may serve for fixing the last holder 15 to the last 1, e.g. by bolts, screws, or other releasable fixing means being led down through e.g. corresponding bores or the like in the last holder and secured in the one or more openings 18, 19 in the last 1. The strength of the attachment structure 17, e.g. the one or more openings 18, 19 in the last 1 may be secured or increased by a number of mounting structures 28 as indicated in FIG. 5.
[0113] As mentioned above, the last 1 may be manufactured by additive manufacturing, where the side wall 8 as well as the mounting structures 28, as well as the attachment structure 17 are produced continuously in a continuous process, where the side wall 8, mounting structures 28 and the attachment structures 17 etc. are integrated with each other, and may provide a continuous structure.
[0114] As further shown in FIG. 6, the movable last body part, e.g. in this example the heel body 42 may be moved in relation to the last body, e.g. the last main body 10. The heel body 42 may be attached to a rear part of the last body, where the heel body may be moveable via e.g. hinge means connecting the parts or the like or the heel body may be moved relative to the last body, guided by any other suitable means as it will be discussed further below. As illustrated in FIG. 6, the heel body 42 may be moved in the vertical direction and may be turned as well. In this way, when a footwear upper is to be attached to the last 1, the heel body 42 may be moved in a direction along a plane which intersect the longitudinal and/or vertical axis of the last body, allowing the heel body to reduce the length of the last body, and to make it easier to mount as well as to remove footwear uppers from the last 1. It is noted that in case the last is designed with an inner volume, at least a dividing wall 8′ may preferably be located at or near the dividing line as indicated in FIG. 6.
[0115] It is noted that the movable last body part, e.g. in this example the heel body 42 may be locked in the position, where it together with the last body defines a last having the shape of a human foot. Locking means may be arranged to lock the e.g. heel body and the last body together in this position, means may be arranged at the top part of the last to secure the position, top lock means may be arranged, etc.
[0116] In FIGS. 5 and 6 it has been indicated and it has been mentioned that the last 1, e.g. the last main body 10 and possibly the movable last body part 40 may have been made with a wall 8 defining an external surface, and where an inner volume may be present. However, it is noted that the last 1, e.g. the last main body 10 and/or the movable last body part 40 may be made as solid structures, which is illustrated in FIG. 7. Here, it is shown that thus, the attachment structure 17 in the upper surface 6 may be the first and the second opening 18, 19 within the solid material of the last 1. It is noted that the last 1, the last main body as well as the movable last body parts may also in such embodiments be made by additive manufacturing.
[0117] FIG. 8 corresponds to FIG. 6, but in FIG. 8 it is illustrated schematically that the movable last body part 40, e.g. in this example the heel body 42 may take various forms as illustrated with the various dividing lines D, e.g. rectilinear, curved, vertical, etc. Thus, as it will be seen, the heel body 42 may comprise the rear part of the last 1 with the dividing line D passing at the last top between the first opening 18 and the second opening 19, which entails the possibility of controlling the relative movement and/or locking of the parts via the last holder arrangement or the like.
[0118] FIG. 9 corresponds to FIGS. 6 and 8, but in FIG. 9 it is illustrated schematically that the movable last body part 40 may be another part of the last body than the heel, e.g. in this example a part of the upper front of the last 1, e.g. an upper part stretching from or near the toe part and to the top part of the last 1 as illustrated by the dividing line D. By such a movable last body part 40 attaching and/or removing a footwear upper or a completed piece of footwear may be facilitated as well. Other options for providing a movable last body part 40 may be available. Further, the movable last body part 40 may be a toe body as also illustrated by the dividing line D and as it has been shown in FIGS. 4a-c.
[0119] As noted above in connection with FIGS. 5 and 6, it is also noted for FIGS. 8 and 9 that in case the last 1 is designed with an inner volume, at least a dividing wall may preferably be located at or near the dividing line D to facilitate the arrangement of guiding structures, hinge arrangements or similar means.
[0120] With reference to FIGS. 10 and 11 an embodiment of a movable heel body 42 and the corresponding last main body will be described, wherein the heel body 42 is configured to move by sliding along the corresponding part of the last main body. The dividing line D is illustrated as having a curved form. Furthermore, it is illustrated that a guiding structure 54 may be arranged in dividing wall parts 56, e.g. arranged along the dividing line D, such that these dividing wall parts may slide along each other. These dividing wall parts 46 may be made, e.g. by additive manufacturing, simultaneously with the manufacturing of the last body, e.g. the last main body, and the movable last body part. Optionally, the dividing wall parts 56 may be made to close off the inner volume/volumes of the last body and/or the movable last body part partly or totally. The guiding structure 54, which will be further exemplified with reference to FIGS. 12, 13 and 14, may thus be integrated with these dividing wall parts 56, e.g. by additive manufacturing.
[0121] Other possible embodiments may involve that the guiding structure/structures 54 may be made as separate elements, for example of metal, polymers, composites, etc, and assembled with e.g. the last main body and/or the movable last body part.
[0122] Also, it should be noted that the last main body and/or the movable last body part may be in the form of essentially solid elements and not in form of elements having a wall, which encompasses an inner volume. Such essentially solid elements may for example be elements made by additive manufacturing. It will be understood, though, that such solid elements may comprise smaller voids within the structure and may even comprise e.g. honeycomb structures or the like.
[0123] Possible configurations of the guiding structure 54 are illustrated in a schematic manner in FIGS. 12, 13 and 14, which are transverse sectional views as indicated by E in FIG. 10. Thus, it is shown in FIG. 12 that an exemplary guiding structure 54, which is provided by the dividing wall parts 56 of the heel body and the last main body may be e.g. cooperating structures such as tongue and groove structures, which allow a sliding action to be performed while simultaneously controlling the e.g. transverse relative position of the last main body and the movable heel body.
[0124] FIG. 13 shows a corresponding transverse sectional view as indicated by E in FIG. 10, where it is shown that an exemplary guiding structure 54 provided by the dividing wall parts 56 of e.g. the heel body and the last main body may be cooperating dovetail structures or the like, which allow a sliding action to be performed while simultaneously controlling the e.g. transverse relative position of the last main body and the movable heel body. Other options for such guiding structures are possible, which will be apparent to a skilled person.
[0125] FIG. 14, which is a corresponding transverse sectional view as indicated by E in FIG. 10, shows a further option for such guiding structures 54 having a tongue and groove structure. Here, the tongue part 62, which may stretch essentially along a major part of the cooperating wall parts (e.g. 50 and 52 as shown in FIG. 1c), and the tongue part 62 may have a T form as shown in FIG. 14, which T formed tongue part 62 will cooperate with a correspondingly shaped groove 60, such that a sliding action or movement is allowed to be performed while simultaneously controlling the e.g. transverse relative position of the last main body and the movable heel body.
[0126] FIG. 15 shows a further transverse sectional view of a guiding structure 54 for movement between a last main body 10 and a movable last body part 40, e.g. a movable heel, toe body, etc. It is noted that the last main body 10 and the movable last body part 40 are not formed with an outer wall surrounding an inner volume, but are formed to be essentially solid, at least where the section is taken. The guiding structure 54 is of the type as illustrated in FIG. 14, e.g. with a tongue part 62 having a T form, which T formed tongue part 62 will cooperate with a correspondingly shaped groove 60. The guiding structure 54 may be located in or near the transverse centre (e.g. the longitudinal centre LC) of the last main body 10 and the movable last body part 40 and it is noted that on one or preferably both sides there may be supporting wall parts 64 and 66, e.g. parts of the cooperating wall parts 50 and 52 that have been shown in e.g. FIG. 1c. These supporting wall parts may serve to increase the guidance of the moving last parts. The last main body 10 and the movable last body part 40 are primarily guided by the guiding structure 54, but during load, e.g. when a upper is being pulled onto a last, when the last is gripped by a mould, when an upper, to which a sole has been moulded, is being delasted, etc, the stability of the construction will be increased by the supporting wall parts 64 and 66 that will be in contact with each other (In FIG. 15 a small distance between wall parts is shown for clarity only) and prevent e.g. rocking of the movable last body part 40 in relation to the last main body 10 and in relation to a longitudinal axis of the last.
[0127] It should be noted that in an advantageous embodiment, supporting wall parts 64 and 66 are formed by a 3D printed structure. In this way, very cost-consuming parts of the last may be formed in a relatively cost-effective and time effective manner, even in spite of the fact that these supporting wall parts 64 and 66 are critical for the purpose of obtaining a mechanically stable assembly, both when the movable last body is fixed or moving relative to the last main body.
[0128] It should be noted that the meaning or definition of supporting wall parts 64 and 66 is meant to designate cooperating surfaces pointed towards each other and located in the transverse direction between the longitudinal centre LC of the last main body and outer circumference of the last OC and the such cooperating surfaces are present and 3D printed on both sides of the longitudinal centre LC as illustrated in FIG. 15 as supporting wall parts 64′ and 66′ and supporting wall parts 64″ and 66″. Together, these surfaces provide the desired stability and the stability may be provided by 3D printing of these surface.
[0129] The area of the 3D printed supporting wall parts 64′ and 66′ and supporting wall parts 64″ and 66″ is at least 5% of the total area of the supporting wall parts 64 and 66, such as at least 10%, such as at least 20%, such as a least 30%, such as at least 40%, such as at least 50%, such as at least 60%, such as at least 70%, such as at least 80%.
[0130] In an embodiment of the invention the area of the 3D printed supporting wall parts 64′ and 66′ and supporting wall parts 64″ and 66″ is between 5% and 50% of the total area of the supporting wall parts 64 and 66, such as between 5% and 40%, such as between 7 and 35%.
[0131] FIG. 15a highlights the meaning of supporting wall parts and the extent and function of these. The arrows A1, A2, A3, A4 illustrate the extent in cross-section of the respective supporting wall part 66′, 64′, 66″ and 64″. This area may vary in size as explained above, but in a preferred embodiment a very large part to the contacting shape defining surface between the last main body 10 and the movable last body part 40 is provided by additive manufacturing, e.g. 3D printing, as this is an extremely cost efficient way of providing crucial shapes and parts of the last and it is also noted that even such critical surfaces, the supporting wall part 66′, 64′, 66″ and 64″, may be provided in sufficient precision and as resistant to stress during use.
[0132] It should of course be noted that the size of the surface of the illustrated and mentioned supporting wall parts 66′, 64′, 66″ and 64″ is referred to as a minimum area requirement as starting from the sides of the last and illustrated by the arrows A1, A2, A3, A4. When an area size is at least 30% for the supporting wall parts 66′, 64′, 66″ and 64″ when compared to the total area of the supporting wall parts 64 and 66, this may of course include that even 60% of the total area is manufactured by additive manufacturing. The important part is to ensure that the desired precision in shape between the moving part and the last main body is obtained while at the same time obtaining a durable stress resistant assembly both during lasting, de-lasting, optional molding, surface treatment of the upper, etc.
[0133] FIG. 16 shows a further transverse sectional view of a guiding structure 54 for movement between a last main body 10 and a movable last body part 40, essentially corresponding to FIG. 15, but where it is illustrated that a separate guiding structure 58 is attached to the movable last body part 40. This separate guiding structure 58 comprises e.g. the tongue 62 of the guiding structure 54 and the supporting wall parts 64. Instead, it may have comprised the groove part 60 and/or it may be configured to be attached to the last main body 10, as it will be apparent to a skilled person. It is noted that such a separate guiding structure 58 may be manufactured by additive manufacturing or in any other suitable manner. Similar reasonings as regards e.g. the area of the 3D printed supporting wall parts 64′ and 66′ and supporting wall parts 64″ and 66″ as discussed in connection with FIG. 15 apply also in regard to the embodiment shown in FIG. 16.
[0134] FIG. 16a illustrates a general variant of the above illustrated embodiment of FIG. 16, where the separate guiding structure 58 illustrated is now formed by a separate tongue 62, which may be e.g. 3D printed, formed by extrusion, milling or other suitable manufacturing, thereby providing a connection between the movable body part and the main body, which is made by a durable material having a strength which is higher that the 3D printed material of main part of the movable last body part 40.
[0135] Likewise, and optionally, the embodiment may further include a separate tongue counterpart 58′ attached to the last main body 10. The separate tongue counterpart 58′ may likewise, if applied, preferably be made in a material which is durable and strong enough to ensure that the assembly of the movable body part 40 and the last main body can endure during use-invoked stress. The two separate tongue parts 58 and 58′ may e.g. be produced in standard sizes or in sets of sizes of conventionally produced metal or nylon material, whereas the last body parts defining the customized shapes may be formed by additive manufacturing, e.g. 3D printing, thereby ensuring that the complex, individually varying and expensive part of the last may be made by a relative cost efficient technique.
[0136] FIGS. 17a and 17b show in a schematic manner horizontal or inclined sectional views of a last main body 10, which is assembled with a movable last body part 40 such as e.g. a heel body, a toe body, etc. The two parts are assembled with a guiding structure 54 and as shown in FIGS. 17a and 17b, the guiding structure 54 involves a separate guiding structure 58 that is attached to the last main body 10, e.g. by bolts, screws, etc. (not shown). The separate guiding structure 58 comprises the tongue 62 of the guiding structure 54 and the corresponding groove 60 is formed in the movable last body part 40. The form of the tongue 62 of FIG. 17a differs from the form of the tongue 62 of FIG. 17b. As it has been mentioned above, the guiding structure 54 may instead comprise the groove part 60 and/or it may be configured to be attached to the movable last body part 40, as it will be apparent to a skilled person. It is noted that such a separate guiding structure 58 may be manufactured by additive manufacturing or in any other suitable manner.
[0137] Further, it is noted that the separate guiding structure 58 for one or both of the last main body 10 and the movable last body part 40 may possibly be made as standard elements, e.g. with standard dimensions and/or standard curvature, etc. that may be incorporated into last assemblies having e.g. different sizes, forms, etc. Such standard elements may for example be cut off to length to match a particular size last main body and/or movable last body part. It is also noted that such a separate guiding structure 58 may conform in width to e.g. a last main body 10 as shown in FIGS. 17a and 17b. Alternatively, a separate guiding structure 58 may be e.g. slimmer and be assembled with the last main body 10 as a part that may be positioned and fixed into a groove or the like. Hereby, separate guiding structures may be made as standard elements, e.g. profiles of polymer, metal, etc. that can be cut to length and incorporated in a wide variety of last sizes. Alternatively, separate guiding structures may be made by 3D printing.
[0138] FIG. 18 shows an example of a last main body 10, seen in a perspective view from the side, which last main body 10 is configured to operate with a movable heel body, e.g. a heel body as shown in FIG. 19. The last main body 10 is shown having a toe end 2, a lower surface 7 and an upper surface 6, where the latter is configured to be attached to a last holder (not shown) as it has been described above. Furthermore, it is indicated with dash lines that the last main body 10 at the upper rear part, at a position above the intended position for the heel body, may comprise an operator rod 70 or may be designed for accommodating an operator rod or the like to facilitate the movements of the movable heel body 42. Furthermore, it is shown in FIG. 18 that the cooperating wall 50 (as shown in e.g. FIG. 1c) of the last main body has a tongue 62 that stretches along a substantial part of the curved cooperating wall 50. The tongue 62 actually shown in FIG. 18 is T-formed, corresponding to FIGS. 14-17b, but it is apparent that another suitable form may be utilized, depending on the actual requirements.
[0139] The heel body 42 shown in FIG. 19 has a cooperating wall 52 (as shown in e.g. FIG. 1c), corresponding to the cooperating wall 50 of the last main body 10. Furthermore, it has been configured with a groove 60, which has a T-form corresponding to the form of the tongue 62. It will be understood that when assembling the last main body 10 as shown in FIG. 18 with the heel body 42, the heel body will be entered from below the last main body 10 in such a manner that the tongue 62 is being introduced into the upper part of the groove 60. Also, it is indicated that the heel body has an operator connection 72, which for example may be connected to an operator rod 70 or the like that via the last main body 10 and/or via a last holder (not shown) may effect that the heel body 42 can be moved up and down in relation to the last main body 10, as it has been described above in connection with e.g. FIGS. 1a-c.
[0140] In FIG. 18 and FIG. 19 the surface of the last parts made by additive manufacturing is made to have a low-friction smooth last defining surface.
[0141] It should generally be noted that the last parts provided according to the provisions of the invention may be additively manufactured to final shape or they may be additively manufacturing to a shape for subsequent smoothing post processing such as polishing or sanding.
[0142] This includes the movable last body part(s). This is important to obtain low friction movement between last main body part(s) and movable body part(s), but also to obtain a low friction between a footwear upper and the last during lasting and de-lasting.
LIST OF REFERENCES
[0143] 1 Last [0144] 2 Toe end [0145] 3 Heel end [0146] 4 Medial side [0147] 5 Lateral side [0148] 6 Upper surface [0149] 7 Lower surface [0150] 8 Wall [0151] 8′ Dividing wall [0152] 9 External surface [0153] 10 Last main body [0154] 15 Last holder [0155] 17 Attachment structure [0156] 18 First opening [0157] 19 Second opening [0158] 28 Mounting structure [0159] 40 Movable last body part [0160] 42 Heel body [0161] 44 Forefoot body [0162] 46 Upper forefoot body [0163] 48 Toe body [0164] 50 Cooperating wall of last main body [0165] 52 Cooperating wall of movable last body part [0166] 54 Guiding structure [0167] 56 Dividing wall part [0168] 58 Separate guiding structure [0169] 60 Groove [0170] 62 Tongue [0171] 64, 66 Supporting wall parts [0172] 64′, 64″ Supporting wall parts [0173] 66′, 66″ Supporting wall parts [0174] 70 Operator rod [0175] 72 Operator connection [0176] D Dividing line [0177] E Transverse sectional view [0178] LC longitudinal centre [0179] OC Outer circumference of the last
