Last assembly

Abstract

This invention discloses a shoe last assembly, including a shoe last comprising a front part and a rear part. The front and rear parts of the shoe last form a detachable connection, with the connection point between them defined at a position corresponding to the tarsal bone of the foot. The foremost point along the length direction and the two lateral ends along the width direction of the shoe last are both located at the front part. One of the rear end of the front part and the front end of the rear part of the shoe last has a boss, and the other has a recess. Both the rear end of the front part and the front end of the rear part of the shoe last have contact surfaces. A screw passes between the front and rear parts of the shoe last. This invention's shoe last assembly allows for changing the style and size of the front end of the shoe last by disassembling and replacing the front part. It features a simple connection structure, convenient disassembly and replacement, a small gap at the connection point, and a smoother shoe last surface.

Description

Technical Field

[0001] This invention relates to a shoe last assembly, which is particularly suitable for the injection molding process of shoe manufacturing. Background Technology

[0002] As the molding mold for shoes, the shoe last not only determines the shape and style of the shoe, but also whether it fits the foot and can provide protection. Traditional shoe lasts are designed to mimic the shape of the foot, as shown in the attached image. Figure 1 , 2 As shown in Figure 4, it includes a front end a, a rear end b, a side end c, and a side end d. The front end a corresponds to the toe part, the rear end b corresponds to the heel part, and the side ends c and d correspond to the two farthest parts of the foot along the width direction. Figure 3 The illustration shows a normal human foot bone model, in which a first joint is located between the first metatarsal bone and the first proximal phalanx, and a second joint is located between the fifth metatarsal bone and the fifth proximal phalanx. Lateral ends c and d are respectively positioned at positions corresponding to the first joint and the second joint.

[0003] Depending on the style of the shoe's front end, the shoe last is usually designed with pointed or rounded corners, for example... Figure 1 , 2 The image shows a shoe last with a pointed front design. Figure 4 The image shown is of a shoe last with a rounded front design.

[0004] In addition, different wearers have different foot sizes. The most obvious difference is that there are certain differences in the length and width of the foot. The length of the foot is reflected in the shoe last as the distance between the front end a and the back end b, while the width of the foot is reflected in the shoe last as the distance between the side end c and the side end d.

[0005] For the reasons mentioned above, shoe manufacturers often need to configure many different styles and sizes of shoe lasts in order to produce shoes with different front-end styles and to fit the foot sizes of different wearers, which keeps the cost of shoe manufacturing high.

[0006] Chinese utility model patent discloses an adjustable shoe last that is easy to install and disassemble (CN217851623U). In this patent, the traditional shoe last is decomposed into a fixed body and an adjustment block. The fixed body and the adjustment block are connected by a special connection structure. In addition to enabling the disassembly of the fixed body and the adjustment block, this connection structure also enables the adjustment of the overall length of the shoe last.

[0007] However, the shoe last described in the aforementioned patent employs a relatively complex connection method between its various components, resulting in numerous connecting parts and significant manufacturing difficulties for each component. Furthermore, the precision of adjusting the shoe last length needs improvement. Due to the large gaps between its fixing body and adjusting blocks, the surface smoothness of the shoe last is poor, affecting the precision of shoemaking and making it unsuitable for shoemaking processes such as injection molding.

[0008] Furthermore, a Chinese invention patent application recently filed by the applicant discloses a shoe last assembly (CN115024560A), including a shoe last and a support base that is fixed to the shoe last. The shoe last includes a forefoot portion and a heel portion, which are slidably connected. The support base includes a first support base fixed to the lower end of the forefoot portion and a second support base fixed to the lower end of the heel portion, with the heel portion and the second support base forming a lateral insertion positioning fit. Each side of the forefoot and heel portions includes a wear-resistant portion. The forefoot and heel portions are connected by a slidable fit. After the shoe is manufactured, by sliding the forefoot and heel portions relative to each other, the overall length of the shoe last is reduced, making it easy to remove the shoe from the shoe last.

[0009] To enable relative sliding between the forefoot and heel, the abrasion-resistant part of the forefoot includes a T-shaped guide rail, and the abrasion-resistant part of the heel includes a guide groove. The cooperation of the guide rail and guide groove forms a sliding connection between the forefoot and heel, allowing the heel to move up and down relative to the forefoot. The abrasion-resistant part reduces wear during relative sliding, extending the lifespan of the shoe last. Furthermore, the abrasion-resistant part reduces the manufacturing difficulty of the shoe last. Currently, traditional shoe lasts are formed using CNC milling. Due to technological limitations, directly machining the matching guide rails and guide grooves on the forefoot and heel is not only time-consuming and labor-intensive, but also results in low precision in the fit between the forefoot and heel, failing to meet the demands of high-precision shoe manufacturing. Therefore, currently, abrasion-resistant parts with guide rails or guide grooves are machined separately and then fixed to the forefoot / heel using glue or fasteners. While this traditional processing method has solved the problem of machining accuracy at sliding fits, it still suffers from low production efficiency, numerous process steps, and high production costs.

[0010] Furthermore, in the aforementioned patent documents, the foot portion of the shoe last and the first support base, as well as the heel portion of the shoe last and the second support base, employ a lateral insertion and positioning mechanism. After insertion, the two components are restricted by a first and a second limiting member to prevent separation. Additionally, the first support base has positioning recesses on both sides for engagement with the gripper of a robotic arm. The inner hole of the second limiting member can also engage with a pin on the tooling fixture of the shoemaking workbench for positioning.

[0011] The aforementioned shoe last assembly features a relatively reliable connection between the support base and the shoe last. However, the connection structure is complex, with numerous connection features, and the assembly process is cumbersome. Once assembled, the support base and shoe last are difficult to disassemble and replace. Because the support base frequently needs to coordinate with fixtures, robotic arms, and pallets on the shoe production line for positioning, it is prone to wear and tear after prolonged use, potentially leading to a decrease in shoe manufacturing precision. Often, the entire shoe last assembly needs to be replaced after extended use, increasing shoe manufacturing costs. Furthermore, due to its limited lifespan, the support base is typically made of harder, more wear-resistant materials, such as steel, which also increases the cost of the shoe last assembly and makes it heavier, hindering its transfer and transportation. Summary of the Invention

[0012] To address the shortcomings of existing technologies, this invention provides a shoe last assembly that allows for changes in the front-end style and size of the shoe last through disassembly and replacement of the front part. It features a simple connection structure, convenient disassembly and replacement, a small gap at the connection point, and a smoother surface on the shoe last.

[0013] To achieve the above objectives, the present invention provides a shoe last assembly, including a shoe last comprising a front part and a rear part, wherein the front part and the rear part of the shoe last are detachably connected and fitted together, and when the front part and the rear part of the shoe last are combined and connected together, a complete shoe last can be formed. The connection point between the front part and the rear part of the shoe last is defined at a position on the shoe last corresponding to the tarsal bone of the foot. The foremost point along the length direction and the two lateral ends along the width direction of the entire shoe last are both located at the front part of the shoe last. Since the shape and size of the back of shoe lasts are generally the same for different front-end styles and sizes, by disassembling and replacing the front part of the shoe last, such as replacing the front part with a different length, width, or shape (e.g., rounded corners, pointed corners), the overall width (distance between the two outermost ends along the width direction) and length (distance between the front and rear ends along the length direction) of the shoe last can be adjusted. At the same time, the style of the front end of the shoe last can also be changed. Thus, by combining and changing the style, the shoe last can be made suitable for the manufacture of shoes with different front-end styles and different sizes, thereby reducing the production or purchase cost of shoe lasts.

[0014] One of the rear end of the front part and the front end of the rear part of the shoe last is provided with a boss, and the other is provided with a recess that cooperates with the boss to form a mating fit that prevents relative rotation. The prohibition of relative rotation means that the boss and the recess cannot rotate relative to each other after being mated and positioned. In order to prevent relative rotation between the front and rear parts of the shoe last, the connection between the boss and the recess can adopt a non-circular contour. The rear end of the front part and the front end of the rear part of the shoe last both have annular contact mating surfaces arranged around the boss or recess. A screw is passed between the front and rear parts of the shoe last. The screw is arranged along the mating direction of the front and rear parts of the shoe last and locks the front and rear parts of the shoe last in a mating state, improving the reliability of the connection between the front and rear parts of the shoe last, avoiding relative movement or separation between the front and rear parts during the shoe manufacturing process, and also ensuring that the contact mating surfaces of the front and rear parts of the shoe last are pressed together.

[0015] The shoe last of this invention employs the aforementioned connection and fitting method for its front and rear portions, resulting in a simple structure and convenient assembly and disassembly. Furthermore, because the contact surfaces of the front and rear portions are tightly fitted together, the gap at the connection point is reduced, leading to a tighter connection, ensuring the smoothness of the shoe last surface, and improving shoe manufacturing precision. In particular, this invention makes the shoe last more suitable for continuous injection molding processes, which is beneficial for improving shoe manufacturing precision and quality during the sole injection molding stage of such processes.

[0016] Furthermore, an annular rib is provided on one of the contact surfaces of the rear end of the front part and the front end of the rear part of the shoe last, and an annular groove is provided on the other contact surface to mate with the rib. When the front and rear parts of the shoe last are connected, the rib will be inserted into the groove. In the sole injection molding process of the upper injection molding, this can prevent molten liquid from seeping in and improve the shoe manufacturing effect.

[0017] Furthermore, a gasket adapted to the shape of the contact mating surface is fitted onto the protrusion. The gasket presses against the contact mating surfaces of the rear end of the front part and the front end of the rear part of the shoe last. When the front and rear parts of the shoe last are fixed together by screws, the contact mating surfaces of the front and rear parts are fully pressed against the gasket, which can further reduce the gap at the connection. When the two contact mating surfaces have ribs and grooves respectively, the gasket can deform and press against the insertion joint of the ribs and grooves, which can further improve the effect of preventing molten liquid from seeping in during the injection molding process of the sole. In addition, the overall length of the shoe last after final assembly can be finely adjusted by replacing gaskets of different thicknesses, thereby compensating for errors in processing precision.

[0018] Furthermore, the rear of the shoe last is hollow, and the screw's shank connects and engages with the front of the shoe last. The screw head passes through the rear of the shoe last, which has mounting holes for inserting the screw and for inserting a tightening tool. The hollow rear of the shoe last reduces its overall weight, saves on raw materials, and lowers manufacturing costs. The screw head is inserted into the rear of the shoe last through the mounting holes, and then a tightening tool, such as a screwdriver, is inserted along the mounting holes to tighten the screw. The structure is simple and installation is convenient. The screw being hidden inside the mounting holes makes the shoe last look neater and more aesthetically pleasing.

[0019] Furthermore, the rear part of the shoe last includes a first part and a second part. The rear part of the shoe last is connected to the front part of the shoe last through the first part. The first part and the second part are slidably connected. The deformation of the shoe last is achieved by the relative sliding of the first part and the second part, which facilitates the removal of the last. The first part is hollow, and the head of the screw is placed inside the first part. The mounting hole is set on the sliding mating surface of the first part corresponding to the second part. Setting the mounting hole at this location allows it to be covered by the second part, which helps to maintain the smoothness of the outer surface of the shoe last, reduce gaps, improve the precision of shoemaking, and improve the overall aesthetics of the shoe last.

[0020] Furthermore, the front part and the second part of the rear part of the shoe last are both hollow, which can further reduce the weight of the shoe last, save the use of shoe last raw materials, and reduce the manufacturing cost of the shoe last. The front part, the first part of the rear part, and the second part of the shoe last are all provided with material discharge holes. The material discharge hole of the front part of the shoe last is located at the connection between the front part and the first part of the rear part of the shoe last. The material discharge hole of the first part of the rear part of the shoe last is located at the connection between the front part and the first part of the rear part of the shoe last or at the connection between the first part and the second part of the shoe last. The material discharge hole of the second part of the rear part of the shoe last is located at the connection between the first part and the second part.

[0021] Because debris is generated during the machining of the internal cavities in the front, first, and second parts of the shoe last, the discharge holes can discharge this debris. The discharge holes in the front of the shoe last or in the first part at the rear can be located on its boss or recess. Alternatively, the discharge hole in the first part can be located on its sliding mating surface at the rear end, or the mounting hole in the first part can be used as a discharge hole. The discharge hole in the second part is located on its sliding mating surface. This structural design makes the discharge holes more concealed, improves the overall aesthetics of the shoe last, helps maintain the smoothness of the shoe last's outer surface, and improves the precision of shoe manufacturing.

[0022] Furthermore, the first and second rear portions of the shoe last are each integrally formed with sliding connecting parts that constitute a sliding connection fit. The front, first, and second rear portions of the shoe last are integrally formed using 3D printing technology, and the hollow internal structure of these components is integrally formed using 3D printing technology. By manufacturing shoe lasts using 3D printing technology, the hollow front and rear portions of the shoe last can be directly printed, and the aforementioned sliding connecting parts can be integrally printed directly on the first and second rear portions. This simplifies the manufacturing and assembly process of shoe lasts and overcomes the shortcomings of low processing accuracy and low yield rate of traditional CNC milling processes.

[0023] Furthermore, the shoe last assembly includes a first support seat that laterally inserts into the first rear portion and a second support seat that laterally inserts into the second rear portion. Limiting members are provided between the first portion and the first support seat, and between the second portion and the second support seat. These limiting members restrict lateral relative movement between the first portion and the first support seat, and between the second portion and the second support seat. The limiting members have positioning holes for positioning with clamps, pins, or robotic arms of shoemaking equipment. After the first and first rear portions of the shoe last are laterally inserted into each other, and the second and second rear portions are laterally inserted into each other, the limiting members restrict lateral relative movement, making the connection more reliable. By providing positioning holes for positioning with clamps, pins, or robotic arms of shoemaking equipment on the limiting members, the structure of the shoe last assembly is simplified, facilitating its processing and manufacturing.

[0024] Furthermore, the limiting member includes a smooth section that interlocks with the first / second part of the shoe last and a threaded section that threadedly connects with the first / second support base. The inner end of the positioning hole of the limiting member is provided with a connecting groove for screwing with a screwing tool. The limiting member interlocks with the first / second part of the shoe last via its smooth section and with the first / second support base via its threaded section. Using this connection method, the limiting member and the shoe last only have an interlocking and limiting relationship; no threads are needed on the shoe last. Therefore, when the support base is damaged after long-term use, it can be easily replaced without easily damaging the connection point of the shoe last, thus improving the service life of the shoe last. The connecting groove can be used to connect with a screwing tool; for example, the connecting groove can be a hexagonal groove. The head of the screwing tool is inserted along the positioning hole and engages with the connecting groove, driving the limiting member to rotate, facilitating the installation and fixation of the limiting member.

[0025] Furthermore, there are two limiting members, which are respectively disposed on both sides of the first support / second support along the width direction of the shoe last. One limiting member forms a non-rotating insertion fit with the front / rear part of the shoe last, while the other limiting member forms a rotatable insertion fit with the first / second part of the shoe last. One end of the two limiting members forms a threaded connection. After connection, the two limiting members form a limiting fit with the first / second part of the shoe last along the insertion direction. The inner end of the positioning hole of the other limiting member is provided with a connecting groove for screwing with a screwing tool. When the two limiting members are inserted between the first / second part of the shoe last and the first / second support, a connection is established by threads, so that the two limiting members and the limiting members and the first / second part of the shoe last can be reliably connected together. Furthermore, this connection method eliminates the need for threads on the shoe last. After long-term use and wear, the support seat can be easily replaced without significantly affecting the shoe last's connection point, thus extending its lifespan. It also ensures that the positioning holes on both limiting components are aligned with each other on both sides of the support seat, improving the precision of the fit with shoe production line equipment.

[0026] In this invention, the limiting component not only strengthens the connection reliability between the shoe last and the support base, but its connection and fit with the shoe last and support base also improves the service life of the shoe last and facilitates the disassembly and replacement of the support base. Furthermore, because the limiting component has positioning holes, it eliminates the need for additional positioning holes on the support base or shoe last, simplifying the overall structure of the shoe last assembly and facilitating manufacturing and assembly. In addition, it reduces the rigidity requirement of the support base material, allowing for the replacement with a support base made of a cheaper and lighter material, thus reducing the weight of the shoe last assembly and lowering shoe manufacturing costs.

[0027] The beneficial effects of the present invention are as follows: The shoe last assembly of the present invention includes a front part and a rear part, and the front part and the rear part are connected by a detachable plug-in method. By replacing the front part with different sizes and shapes and combining them with the rear part, it can be used to adapt to the manufacture of shoes with different front end styles and to fit different wearers' foot sizes. It can adjust the overall width (distance between the two outermost ends along the width direction) and length (distance between the front and rear ends along the length direction) of the shoe last. Moreover, this connection method will not produce a large gap at the connection between the front and rear parts of the shoe last, making the outer surface of the shoe last smoother. The connection structure is simple and easy to assemble and disassemble, which can simplify the construction of the shoe last and ensure the precision of shoe manufacturing. It is particularly suitable for the injection molding shoe manufacturing process. Attached Figure Description

[0028] Figure 1 A top view of the first type (pointed toe) shoe last in the prior art;

[0029] Figure 2 This is a design drawing of the first type of shoe last in the prior art;

[0030] Figure 3 A schematic diagram of a three-dimensional model of a normal human foot bone;

[0031] Figure 4 This is a top view of a shoe last of the second style (round toe) according to an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the structure of an embodiment of the present invention;

[0033] Figure 6 This is an exploded view of the structure of an embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the assembly of the rear part of the shoe last according to an embodiment of the present invention;

[0035] Figure 8 This is a schematic diagram of the assembly of the front part and the first part of the shoe last according to an embodiment of the present invention;

[0036] Figure 9 This is a side view of an embodiment of the present invention;

[0037] Figure 10 This is a bottom view of an embodiment of the present invention;

[0038] Figure 11 This is a cross-sectional view at the center along the width direction of the shoe last according to an embodiment of the present invention;

[0039] Figure 12 This is an exploded view of the structure of the first support base and the second support base according to an embodiment of the present invention;

[0040] Figure 13 This is a cross-sectional view of the first support base and the second support base according to an embodiment of the present invention;

[0041] Figure 14 This is a structural diagram of the second part of the rear section of the shoe last according to an embodiment of the present invention. Detailed Implementation

[0042] Examples of embodiments of the shoe last assembly of the present invention Figure 1-14 As shown: The shoe last includes a forefoot portion 11 corresponding to the forefoot and a rear portion corresponding to the heel portion (i.e., a combination of the first part 12 and the second part 13). The rear end of the forefoot portion 11 and the front end of the rear end form a detachable connection. When the forefoot portion 11 and the rear end are combined, a complete shoe last is formed. The rear end of the forefoot portion 11 and the front end of the rear end are both positioned on the shoe last at a location corresponding to the tarsal bones of the foot (see reference). Figure 2The tarsal bone portion of the foot bone model), the foremost point a along the length direction and the two lateral ends c and d along the width direction of the shoe last are both located at the front part 11 of the shoe last (reference). Figure 10 , 13 Since the shape and size of the rear part corresponding to the heel of the foot are basically the same for different front-end styles and sizes of shoe lasts, the front part 11 of the shoe last can be disassembled and replaced, for example, by replacing the front part with a different length, a different width, or a different shape. This allows for adjustment of the overall width (distance between the two outermost ends along the width direction) and length (distance between the front and rear ends along the length direction). At the same time, the style of the front end of the shoe last (such as pointed toe, round toe, or other shapes) can be changed. Thus, by combining and changing the parts, the shoe last can be made suitable for the manufacture of shoes with different front-end styles and different sizes. By combining a small number of parts, shoe lasts of different shapes and sizes can be created, which can reduce the production or purchase cost of shoe lasts.

[0043] The front part 11 of the shoe last has a boss 21 at its rear end and a recess 22 at its front end that engages with the boss 21. A screw passes through the front part 11 and the rear part of the shoe last. The screw is arranged along the insertion direction of the front and rear parts of the shoe last. After the front part 11 and the rear part of the shoe last are inserted, they are locked together by the screw, which can lock them in the inserted state, improve the reliability of the connection between the front part 11 and the rear part of the shoe last, and prevent the relative movement or separation between the front part 11 and the rear part during the shoe manufacturing process.

[0044] In addition, such as Figure 6 , 7 As shown, the rear end of the front part 11 and the front end of the rear part of the shoe last both have annular contact mating surfaces 23 arranged around the boss 21 or the recess 22. When the front part 11 and the rear part are connected together by the boss 21 and the recess 22, the contact mating surfaces 23 of the two are pressed together by screws, which can reduce the gap at the connection and ensure the smoothness of the shoe last surface. This makes the shoe last of the present invention particularly suitable for the injection molding process of the upper. In the injection molding process of the upper, it is beneficial to improve the precision and quality of shoe manufacturing.

[0045] The front part 11 and the back part of the shoe last are connected and fitted in the manner described above, which is simple in structure and easy to assemble and disassemble. In order to prevent relative rotation between the front part 11 and the back part of the shoe last, the connection between the boss 21 and the recess 22 adopts a non-circular contour.

[0046] In other embodiments, the boss 21 can also be located at the front end of the rear part, and the recess 22 can be located at the rear end of the front part 11, which can also achieve the same effect.

[0047] An annular rib 24 is provided on the contact mating surface 23 at the front end of the rear part of the shoe last, and an annular groove 25 is provided on the contact mating surface 23 at the rear end of the front part 11 of the shoe last, which is fitted with the rib 24.

[0048] In other embodiments, the rib 24 can also be provided on the contact mating surface 23 at the rear end of the front part 11 of the shoe last, and the groove 25 can be provided on the contact mating surface 23 at the front end of the rear part of the shoe last, which can also achieve the same effect.

[0049] When the front part 11 and the back part of the shoe last are connected, the rib 24 will be inserted into the groove 25 accordingly. In the sole injection process of the last injection molding process, it can prevent the molten liquid from seeping in and improve the shoe making effect.

[0050] To further enhance the above-mentioned effect, a washer 26 adapted to the shape of the contact mating surface 23 is fitted on the boss 21. Under the tightening action of the screw, the washer 26 presses against the contact mating surface 23 between the rear end of the front part 11 and the front end of the rear part of the shoe last. When the washer 26 presses against the front and rear parts of the shoe last, the gap at the connection can be further reduced. When both contact mating surfaces 23 have ribs 24 and grooves 25 respectively, the washer 26 can deform and press against the ribs 24 and grooves 25, which can further improve the effect of preventing molten liquid from seeping in.

[0051] In addition, by replacing the pads 26 with pads of different thicknesses, the overall length of the final assembled shoe last can be finely adjusted to compensate for errors in processing precision.

[0052] The rear of the shoe last is hollow. The screw's shank connects and engages with the front of the shoe last, with the screw head passing through the rear of the shoe last. The rear of the shoe last has mounting holes 121 for inserting the screw and for inserting a screwdriver or other tightening tool. The hollow rear reduces the weight of the shoe last, saves on raw materials, and lowers manufacturing costs. The screw head is inserted into the rear of the shoe last through the mounting holes 121, and then a tightening tool, such as a screwdriver, is inserted through the mounting holes 121 to tighten the screw. The structure is simple and installation is convenient. The screw being hidden inside the mounting holes 121 makes the shoe last look neater and more aesthetically pleasing.

[0053] like Figure 11As shown, the interior of the front part 11 of the shoe last has a solid structure at the corresponding boss 21 position, which provides a relatively reliable connection when connected with screws. Threaded holes for screw connection can be directly machined by tapping the boss 21, or a fixing metal sleeve can be embedded in the boss 21, with the sleeve providing the threaded holes for screw connection. Inside the rear part of the shoe last, a limiting wall 122 is located at the corresponding recess 22 position. The limiting wall 122 has holes for screws to pass through, and there is a limiting fit between the screw head and the limiting wall 122.

[0054] The rear part of the shoe last includes a first part 12 and a second part 13 distributed sequentially in the front-back direction. The rear part of the shoe last is detachably connected to the front part 11 of the shoe last through the first part 12. The first part 12 and the second part 13 are slidably connected. The first part 12 is provided with a T-shaped slider 123, and the second part 13 is provided with a T-shaped groove 131 that is slidably connected with the slider 123. The slider 123 and the groove 131 form a sliding connection between the first part 12 and the second part 13. The relative sliding of the first part 12 and the second part 13 realizes the overall deformation of the shoe last, thereby realizing the last removal action. The last removal principle is to reduce the overall length of the shoe last, so that the shoe can be easily removed from the shoe last after the shoe is made.

[0055] like Figure 8 , 11 As shown, the first part 12 is hollow, the head of the screw is placed inside the first part 12, and the mounting hole 121 is provided on the sliding mating surface of the first part 12 corresponding to the second part 13 (see reference). Figure 8 The mounting hole 121 is positioned here so that it can be covered by the second part 13, which helps to maintain the smoothness of the outer surface of the shoe last, reduce gaps, improve the precision of shoemaking, and enhance the overall aesthetics of the shoe last.

[0056] The front part 11 and the second part 13 of the shoe last are both hollow, which can further reduce the weight of the shoe last, save on the use of shoe last raw materials, and reduce the manufacturing cost of the shoe last. The front part 11 and the first part 12 and the second part 13 of the shoe last are all provided with discharge holes (211, 124, 132). Since debris is generated when processing the internal cavity of the front part 11, the first part 12, and the second part 13 of the shoe last, the debris can be discharged through the discharge holes. The material discharge hole 211 of the front part 11 of the shoe last is located on the top surface of the boss 21 at its rear end (or on the inner wall of the bottom of the recess 22 if the rear end is a recess 22). The material discharge hole 124 of the first part 12 is located on the sliding mating surface at the rear end. The material discharge hole 124 of the first part 12 can also be located on the inner wall of the bottom of the recess 22 at its front end (or on the boss 21 if the front end is a boss 21). In addition, the mounting hole 121 of the first part 12 can also be used as a material discharge hole. The material discharge hole 132 of the second part 13 is located on the sliding mating surface at the front end. This structural design makes the material discharge holes more concealed, improves the overall aesthetics of the shoe last, and helps maintain the smoothness of the outer surface of the shoe last, thereby improving the precision of shoemaking. After the debris is discharged, the material discharge hole 132 can be sealed with filler to prevent dust and foreign objects from entering the inside of the shoe last.

[0057] The first part 12 and the second part 13 at the rear of the shoe last are each integrally formed with sliding connecting parts, i.e., sliders 123 and grooves 131 are integrally connected to the first part 12 and the second part 13, respectively. The front part 11, the first part 12, and the second part 13 at the rear of the shoe last are integrally formed by 3D printing technology, and the hollow structure inside these parts is integrally formed by 3D printing technology. By manufacturing shoe lasts using 3D printing technology, the hollow front part 11 and the rear part of the shoe last can be directly printed, and the sliding connecting parts can be directly printed on the first part 12 and the second part 13 at the rear. Compared with the separate sliding connecting parts used in the prior art, this simplifies the structure and assembly process of the shoe last and makes up for the defects of low processing accuracy and low yield of traditional CNC milling process.

[0058] In addition, the shoe last assembly also includes a first support seat 31 that is laterally inserted into the first part 12 at the rear, and a second support seat 32 that is laterally inserted into the second part 13 at the rear. Limiting members are provided between the first part 12 and the first support seat 31, and between the second part 13 and the second support seat 32. The limiting members are used to restrict the lateral relative movement between the first part 12 and the first support seat 31, and between the second part 13 and the second support seat 32. The limiting members are provided with positioning holes 41, which can be used to cooperate with the clamps, pins or robotic arms of the shoemaking equipment for positioning.

[0059] After the first part 12 and the first support 31 at the rear of the shoe last are laterally inserted, and the second part 13 and the second support 32 are laterally inserted, the relative lateral movement is restricted by the limiting member 4 to achieve locking after insertion, prevent relative movement or separation, and make the connection more reliable. The positioning hole 41, which cooperates with the clamps, pins or robotic arms of the shoemaking equipment for positioning, is set on the limiting member 4, which simplifies the structure of the shoe last assembly and facilitates the processing and manufacturing of the shoe last assembly.

[0060] like Figures 11 to 13 As shown, the first part 12 and the first support base 31 are connected by a limiting member 4a. The limiting member 4a includes a smooth section that forms an insert fit with the first part 12 of the shoe last and a threaded section that forms a threaded connection fit with the first support base 31. The inner end of the positioning hole 41 of the limiting member 4a is provided with a connecting groove 42 for screwing with a screwing tool. The limiting member 4a forms a movable insert fit with the first part 12 of the shoe last through its smooth section and a threaded connection fit with the first support base 31 through its threaded section. With this connection method, there is only an insert and limiting fit relationship between the limiting member 4a and the shoe last. The shoe last does not need to be equipped with threads. After the first support base 31 wears out after long-term use, it can be easily replaced without easily affecting the connection of the shoe last, thus improving the service life of the shoe last. The connecting groove 42 can be used to connect with a screwing tool. For example, the connecting groove 42 can be a hexagonal groove. The head of the screwing tool is inserted along the positioning hole 41 and engages with the connecting groove 42, which can drive the limiting member 4a to be screwed, making it convenient to install and fix the limiting member 4a.

[0061] In other embodiments, the aforementioned limiting member 4a and its associated connecting structure may also be disposed on the second part 13 of the shoe last and the second support 32.

[0062] When the shoe last assembly is clamped and positioned in conjunction with the fixture of the shoe production line equipment, the pin on the fixture is inserted into the positioning hole 41 of the limiting member 4a to restrict the lateral movement of the shoe last assembly and achieve the positioning of the shoe last assembly.

[0063] The second part 13 and the second support base 32 are connected by two limiting members 4b. The two limiting members 4b are respectively located on both sides of the second support base 32 along the width direction of the shoe last. One of the limiting members 4b and the second part 13 of the shoe last form a plug-in fit that prevents relative rotation. One end of the limiting member 4b is provided with a plug-in post 43 with a non-circular outer contour. The end of the plug-in post 43 has a threaded hole. The second part 13 is provided with a corresponding through hole that plugs into the plug-in post 42. After the through hole is plugged into the plug-in post 42, they cannot be opposite each other. The other limiting member 4b and the second part 13 of the shoe last form a rotatable insertion fit. One end of the other limiting member 4b is provided with a screw 44 that is threadedly connected to the threaded hole of the insertion post 43. The two limiting members 4b form a threaded connection between their ends. After connection, the two limiting members 4b form a limiting fit with the second part 13 of the shoe last along the insertion direction of the limiting member 4b, preventing the limiting member 4b from coming off the second part 13. The inner end of the positioning hole 41 of the other limiting member 4b is provided with a connecting groove 42 that cooperates with a screwing tool for screwing. When the two limiting members 4b are inserted between the second part 13 of the shoe last and the second support 32, since one limiting member 4b is restricted and cannot rotate, the other limiting member 4b can be driven to rotate by a screwing tool, which can easily achieve the threaded fit between the two limiting members 4b. The annular surface between the limiting member 4b and the inner edge of the through hole can restrict its movement along the insertion direction.

[0064] The connection method using the aforementioned limiting member 4b eliminates the need for threads on the second part 13 of the shoe last and the second support 32. After long-term use and wear, the second support 32 can be easily disassembled and replaced without easily affecting the connection point of the shoe last, thus extending its service life. Furthermore, it allows for precise alignment of the positioning holes 41 on both limiting members 4b with the opposite sides of the second support 32, improving the fit accuracy with the shoe production line equipment.

[0065] When the shoe last assembly is transferred in conjunction with the robotic arm of the shoe production line equipment, the robotic arm grasps and moves the entire shoe last assembly through the positioning holes 41 of the limiting parts 4b on both sides of the second support 32.

[0066] In other embodiments, the aforementioned limiting member 4b and its associated connecting structure may also be disposed on the first part 12 of the shoe last and the first support seat 31.

[0067] In this invention, the limiting member 4 not only strengthens the reliability of the connection between the shoe last and the support seat, but also improves the service life of the shoe last and facilitates the disassembly and replacement of the support seat. In addition, since the limiting member is equipped with positioning holes, it is not necessary to open additional positioning holes on the support seat or shoe last, which simplifies the overall structure of the shoe last assembly and facilitates processing, manufacturing and assembly.

[0068] The above embodiments are merely one preferred embodiment of the present invention. Ordinary variations and substitutions made by those skilled in the art within the scope of the technical solution of the present invention are all included within the protection scope of the present invention.

Claims

1. A shoe last assembly, comprising a shoe last, the shoe last including a front part and a rear part, the front part and the rear part of the shoe last forming a detachable connection, characterized in that: The connection between the front and back of the shoe last is defined at a position corresponding to the tarsal bone of the foot. The foremost point along the length direction and the two lateral ends along the width direction of the shoe last are both located at the front. One of the rear end of the front part and the front end of the rear part of the shoe last has a boss, and the other has a recess that mates with the boss to form a mating fit that prevents relative rotation. Both the rear end of the front part and the front end of the rear part of the shoe last have annular contact surfaces surrounding the boss or recess. A screw passes between the front and back parts of the shoe last. The screws are arranged along the insertion direction of the front and rear of the shoe last, locking the front and rear of the shoe last in an inserted state and pressing the contact surfaces of the front and rear of the shoe last together. One of the contact surfaces of the rear end of the front of the shoe last and the front end of the rear of the shoe last has an annular rib, and the other contact surface has an annular groove that mates with the rib. A washer adapted to the shape of the contact surface is fitted onto the protrusion, and the washer presses against the contact surfaces of the rear end of the front of the shoe last and the front end of the rear of the shoe last.

2. The last assembly of claim 1, wherein: The rear part of the shoe last is hollow. The screw shank is connected to the front part of the shoe last. The head of the screw passes through the rear part of the shoe last. The rear part of the shoe last has mounting holes for inserting the screw into the rear part of the shoe last and for inserting a screwing tool into the rear part.

3. The last assembly of claim 2, wherein: The rear part of the shoe last includes a first part and a second part. The rear part of the shoe last is connected to the front part of the shoe last through the first part. The first part and the second part are slidably connected. The shoe last can be removed by sliding the first part and the second part. The first part is hollow. The head of the screw is placed inside the first part. The mounting hole is located on the sliding mating surface of the first part corresponding to the second part.

4. The last assembly of claim 3, wherein: The front part and the second part of the rear part of the shoe last are both hollow. The front part, the first part of the rear part, and the second part of the rear part of the shoe last are all provided with material discharge holes. The material discharge hole of the front part of the shoe last is located at the connection between the front part and the first part of the rear part of the shoe last. The material discharge hole of the first part of the rear part of the shoe last is located at the connection between the front part and the first part of the rear part of the shoe last or at the connection between the first part and the second part of the shoe last. The material discharge hole of the second part of the rear part of the shoe last is located at the connection between the first part and the second part.

5. The last assembly of claim 4, wherein: The first and second parts of the rear of the shoe last are each integrally formed with sliding connection parts that constitute a sliding connection fit. The front, the first part of the rear, and the second part of the rear of the shoe last are integrally processed by 3D printing technology. The hollow structure inside these parts is integrally formed by 3D printing technology.

6. The last assembly of claim 4, wherein: It includes a first support seat that is laterally inserted into the first part at the rear, and a second support seat that is laterally inserted into the second part at the rear. Limiting members are provided between the first part and the first support seat, and between the second part and the second support seat. The limiting members are used to restrict the lateral relative movement between the first part and the first support seat, and between the second part and the second support seat. The limiting members are provided with positioning holes.

7. The last assembly of claim 6, wherein: The limiting member includes a smooth section that forms an interlocking fit with the first or second part of the shoe last, and a threaded section that forms a threaded connection fit with the first or second support seat. The inner end of the positioning hole of the limiting member is provided with a connecting groove that cooperates with a turning tool for turning.

8. The last assembly of claim 6, wherein: There are two limiting members. Two limiting members are provided on both sides of the first support and the second support along the width direction of the shoe last. One limiting member and the first part or the second part of the shoe last form a plug-in fit that prevents relative rotation. The other limiting member and the first part or the second part of the shoe last form a rotatable plug-in fit. One end of the two limiting members forms a threaded connection. After the two limiting members are connected, one end of the two limiting members forms a limiting fit with the first part or the second part of the shoe last along the plug-in direction. The inner end of the positioning hole of the other limiting member is provided with a connecting groove that can be screwed in conjunction with a screwing tool.

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