The present invention is in the field of producing footwear. In particular, the present invention is in the field of equipping footwear with an insert.
In recent years, there has been a trend towards waterproof shoes. Waterproof and breathable shoes have been developed that provide for an all-around waterproof structure around the wearer's foot, but at the same time provide breathability, such that moisture and sweat from the wearer's foot can escape from the interior of the shoe. While such waterproof and breathable shoes provide a very convenient feel for the user in a wide range of usage scenarios, the percentage of waterproof footwear among all shoes is still relatively low.
Accordingly, it would be beneficial to provide equipment that allows for waterproofing footwear, while maintaining a high degree of flexibility in the footwear production process. It would further be beneficial to provide a method that allows for waterproofing footwear, while maintaining a high degree of flexibility in the footwear production process.
Exemplary embodiments of the invention include an expandable last for furnishing footwear with an insert, comprising: a form-stable core support element; an expandable shell, arranged around the core support element; a liquid chamber within the expandable shell; and a liquid port, providing liquid communication between the liquid chamber and an external liquid source; wherein the expandable last is insertable into the footwear through a collar of the footwear and wherein, when receiving liquid in the liquid chamber via the liquid port, the expandable shell is configured to expand for pressing the insert towards an inside of the footwear.
Exemplary embodiments of the invention allow for equipping footwear with an insert in a flexible and efficient manner. In particular, exemplary embodiments of the invention allow for equipping footwear with an insert on the inside thereof, when the collar is the only access point to the interior of the footwear. Further in particular, exemplary embodiments of the invention allow for equipping footwear with an insert, when the footwear is otherwise already completely assembled or close to being completely assembled. Footwear may be equipped with a waterproof, breathable insert, such as a waterproof, breathable bootie, and may thus be made waterproof in a convenient, flexible, and efficient manner. In particular, when the footwear has been designed and assembled in accordance with a conventional non-waterproof design and is ready to be worn or close to being ready to be worn, it can still be equipped with a waterproof, breathable insert. In the case of footwear that is ready to be worn, it may also be said that readily assembled non-waterproof footwear may be retrofitted with a waterproof, breathable insert and may, thus, be made waterproof.
According to exemplary embodiments of the invention, the expandable last is insertable into the footwear through a collar of the footwear, and the expandable shell is configured to expand, when receiving liquid in the liquid chamber via the liquid port, for pressing the insert towards an inside of the footwear. The expandable last may be conveniently introduced into the interior of the footwear, and the expandable shell may exert pressure onto the insert with a high degree of uniformity. With the expandable shell expanding upon receiving liquid in the liquid chamber via the liquid port and engaging with the insert, the pressure-balancing effect, inherent to liquids, may be taken advantage of in very close proximity to the insert. With the expandable shell forming the barrier between the liquid chamber, in which the pressure is built up, and the insert, a highly direct and highly uniform pressure may be exerted onto the insert for pressing the insert towards the inside of the footwear. The expandable shell is configured to expand and, thus, to press the insert towards the inside of the footwear during operation of the expandable last. It is understood that the expandable last is configured to receive liquid in the liquid chamber in operation and that the expandable shell is configured to exert the pressure on the insert in operation, when arranged in the footwear.
According to exemplary embodiments of the invention, the expandable last is configured for furnishing footwear with an insert. In particular, the expandable last may be configured for any one or any subset or all of inserting an insert into the interior of the footwear, positioning an insert in the interior of the footwear, mechanically engaging an insert with the inside of the footwear, and attaching/adhering an insert to the inside of the footwear. The expandable last is configured to exert pressure onto an insert against the inside of the footwear via the expandable shell.
The expandable last has a form-stable core support element. The term form-stable core support element relates to a core support element that has a substantially stable shape. In particular, it relates to a core support element that has no active shape adjusting means, such as a spring-loaded actuator, a hydraulic or pneumatic actuator, etc. The term form-stable does not exclude the core support element to have some elasticity and/or allow for some plastic deformation. For example, the core support element may elastically and/or plastically deform, while being pushed into the interior of the footwear. However, by being form-stable, the core support element maintains its general shape. The shape of the core support element may not undergo a substantial transformation and may maintain its general appearance.
The expandable last has an expandable shell, arranged around the core support element. The expandable shell may be made of any material that expands under the pressure of the liquid in the liquid chamber. The expansion of the expandable shell may comprise an elastic deformation and/or a plastic deformation. The expandable shell may be a kind of balloon/bladder that expands upon receiving liquid in the liquid chamber. In particular, the expandable shell may be a balloon around the form-stable core support elements, with the liquid chamber being formed on the inside of the balloon. The expandable shell may be expandable at portions thereof or may be expandable substantially everywhere. In other words, the expandable nature of the shell may be provided in portions thereof or across the whole component. The expandable shell may thus be configured to press the insert towards the inside of the footwear at selected portions of the insert or substantially everywhere along the insert. The expandable shell may be substantially foot-shaped. The foot-shaped nature of the expandable shell may be present in the un-expanded state. It is also possible that the expandable shell assumes a kind of foot shape, when receiving liquid in the liquid chamber.
The expandable last comprises a form-stable core support element and an expandable shell, arranged around the core support element. In this way, the stability/re-enforcing strength of the core support element is combined with the expandable properties of the expandable shell. In this way, a good compromise between insertability of the expandable last and adaptability to the inside contour of the footwear may be achieved.
The expandable last is insertable into the footwear through a collar thereof. In other words, the expandable last is insertable into the footwear through a foot insertion opening of the footwear. In yet other words, the expandable last is insertable into the footwear from the top, when placing the footwear on a table or other horizontal structure in its normal use orientation.
The expandable last comprises a liquid chamber within the expandable shell. The expandable shell may be liquid-tight/liquid proof, in particular water-tight/waterproof. With liquid, in particular water, being used in the liquid chamber in operation, the insert can be pressed towards the insert of the footwear in a particularly efficient manner. As compared to using gas for exerting the pressure, a lower amount of fluid may needed and the need for a high gas pressure may be eliminated. For example, in particular applications, a water pressure of about 0.2 bar may be suitable for pressing an insert towards the inside of the footwear, while air pressures of 6-7 bar would be required for achieving comparable results. Many expandable materials cannot handle such high pressures and would burst/tear, such that the using of liquids provides a much higher degree of design flexibility than using gases for expanding the expandable shell. Also, liquids have beneficial properties, when counter pressure from the outside of the footwear is applied. For example, when applying counter-pressure in a pressure chamber, as described below, the non-compressibility of the liquid allows for using comparably low liquid pressures. As compared thereto, the compressed air within the expandable shell would have to have a much higher pressure, in order to avoid compression due to the counter pressure.
The expandable last has a liquid port, providing liquid communication between the liquid chamber and an external liquid source. A liquid-tight seal may be provided between the liquid chamber and the liquid port. The liquid port may have a connection piece for attaching a liquid line towards the external liquid source. This connection piece may be any suitable male or female, threaded or unthreaded connection piece. It may have a suitable locking mechanism for ensuring a safe connection between the liquid port and the external liquid source/the liquid line. The terminology of the liquid port providing liquid communication between the liquid chamber and an external liquid source means that the liquid port has the capacity to pass liquid therethrough and to allow for liquid communication between the liquid chamber and the external liquid source in operation.
With the expandable last having an expandable shell, the expandable last may be used over a range of shoe sizes. In particular, it is possible that the expandable last is suitable for being used for a range of up to 2 or 3 or 4 or 5 or 6 or 7 or 8 shoe sizes (European shoe sizes). It may thus be possible to cover the whole range of standard adult shoe sizes, i.e. European shoe sizes 35 to 47, with two or three different expandable lasts only. Further, the expandable last may be used for a variety of different shoe styles, with the expandable shell adapting to the inner contour of the footwear via the liquid in the liquid chamber.
According to a further embodiment, the core support element is substantially L-shaped or substantially T-shaped or substantially U-shaped or substantially foot-shaped. In this way, the core support element may be particularly suitable for providing a high degree of stability to the expandable last. The core support element may be dimensioned to extend over at least 50%, in particular over at least 70%, further in particular over between 90% and 100% of the vertical extension of the interior of the footwear and/or over at least 30%, in particular over at least 50%, further in particular over at least 70%, or even over between 90% and 100% of the horizontal extension of the interior of the footwear.
According to a further embodiment, the core support element is rigid. In particular, the core support element may be made of metal or made of a rigid plastic material or made of sintered material. The core support element may be considered rigid in case it does not undergo a deformation during manual introduction of the expandable last into the footwear. The rigid core support element may provide a high degree of stability to the expandable last during use in the footwear.
According to a further embodiment, the core support element is flexible. In particular, the core support element may be resilient, further in particular made from resilient rubber material. The core support element may be considered flexible in case its shape changes temporarily or permanently during manual introduction of the expandable last into the footwear. A flexible core support element may be particularly suitable for an easy introduction of the expandable last into the interior of the footwear. A resilient core support element may provide a good compromise between easy insertability and a high degree of stability, when inserted into the footwear. The core support element may be made from any suitable flexible material. Suitable flexible materials include rubber, polyurethane, silicone, and thermoplastic polyurethane materials. The selection of a rigid material or a flexible material for the core support element may be made dependent on the dimensions of the core support element. In case the dimensions of the core support element are close to the dimensions of the interior of the footwear, a flexible material may allow for a much easier insertability through the collar of the footwear. In case the dimensions of the core support element are substantially smaller than the dimensions of the interior of the footwear, insertability may be less of an issue and a rigid material may be selected.
According to a further embodiment, the liquid chamber comprises substantially the entire volume between the core support element and the expandable shell. In this way, the expandable last is highly flexible, having a large liquid volume in the liquid chamber during operation. The liquid chamber covering such a large volume may also allow the expandable last to have an overall low number of components. In a particular embodiment, the expandable last may be free of additional components between the form-stable core support element and the expandable shell, with the volume between the form-stable core support element and the expandable shell forming the liquid chamber. However, it is also possible that additional components are provided between the core support element and the expandable shell. For example, filler elements, such as filler balls or cuboid filler elements, may be provided between the core support element and the expandable shell. Such filler elements may be free-floating between the core support element and the expandable shell and/or may be attached to the core support element and/or the expandable shell. The filler elements may reduce the liquid volume needed for generating a desired pressure on the insert by the expandable shell. In this way, the furnishing of the footwear with the insert may be achieved in a particularly short time frame.
According to a further embodiment, the core support element comprises at least one liquid supply line, coupled to the liquid port and providing liquid communication between the liquid port and the liquid chamber. The liquid may reach the liquid chamber at one or more desired locations via the at least one liquid supply line. The entirety of the liquid supply lines may also be referred to as liquid supply line system. The at least one liquid supply line may have one or more openings towards the liquid chamber. An efficient distribution of the liquid in the liquid chamber may be achieved, and a beneficial dynamic build-up of the pressure within the expandable shell may be made possible via a suitable design of the liquid supply line system and the opening(s).
According to a further embodiment, the at least one liquid supply line is arranged within the core support element and has at least one opening towards the liquid chamber. The core support element may serve the double purpose of providing stability to the expandable last and helping the liquid distribution in the liquid chamber by housing the at least one liquid supply line.
According to a further embodiment, the expandable shell is elastic. In particular, the expandable shell may be made from any kind of elastic material that is suitable for expanding under liquid pressure and for applying pressure to the insert. The expandable shell may be made from latex material. In particular, the expandable shell may be made from natural latex material or synthetic latex material. It is also possible that the expandable shell is made from another kind of rubber material. Rubber materials, in particular latex materials, may provide for a good compromise between expandability and robustness with respect to changing pressures. Other suitable elastic materials are stretchable membrane materials and multilayer constructions. The expandable shell may be made from a liquid proof, in particular waterproof, material.
According to a further embodiment, the expandable shell is a one-layer structure or a two-layer structure or a three-layer structure. It is also possible for the expandable shell to have a higher number of layers. With the expandable shell having a two-layer or three-layer design, a good compromise between expandability and tear-resistance may be achieved. The two/three layers may be co-extensive. It is also possible that re-enforcing patches may be provided in critical portions of the expandable shell, thus forming a multi-layer structure at selected portions. The two/three layers may be made from the same material or may be adapted to the particular requirements on the inside/outside of the expandable shell. For example, an inner layer may be adapted to cooperate well with the liquid in the liquid chamber, while an outer layer may be adapted to cooperate well with the insert. One or more or all of the layers may be made from a liquid proof, in particular waterproof, material.
According to a further embodiment, the expandable shell has, at least in one or more regions thereof, dimension-specific elastic properties. In other words, the expandable shell may stretch in a particular dimension easier/quicker/at lower pressures than in one or more other dimensions. In this way, the expansion of the expandable shell may be controlled for a particular application/for a particular footwear. Further in particular, the resulting shape of the expandable shell and/or the dynamic application of pressure onto different portions of the insert may be controlled via the dimension-specific set-up of the expandable shell.
According to a further embodiment, the liquid chamber is at least partly filled with an open-cell foam. In particular, the majority of the liquid chamber or substantially the entire liquid chamber may be filled with an open-cell foam. The open-cell foam may allow the liquid to distribute within the liquid chamber, while giving the liquid chamber some inherent shape. In this way, the expandable last may be inherently shaped similar to the interior of the footwear, while still allowing the liquid to adapt the expandable shell to the inner contour of the footwear. The open-cell foam may be any suitable open-cell form. Suitable open-cell foams include open-cell polyurethane foam, silicone foam, natural foam, and polyethylene foam. The open-cell foam itself may expand upon absorbing liquid. However, it is also possible that the open-cell foam substantially maintains its shape upon absorbing liquid. As an alternative/additionally, the liquid chamber may be at least partly filled with a spacer fabric. The spacer fabric may similarly provide some inherent shape to the expandable shell, while allowing the liquid to distribute and “fine-tune” the shape of the expandable shell, when expanding and engaging with the insert. Both the open-cell foam and the spacer fabric have no active shape adjusting means. They have an inherent shape, which may adapt passively to liquid entering the open-call foam/spacer fabric.
According to a further embodiment, the expandable last further comprises at least one expandable liquid bag, arranged outside or inside of the expandable shell. In particular, the expandable last may comprise at least one expandable liquid bag, arranged outside of the expandable shell, and/or may comprise at least one expandable liquid bag, arranged inside of the expandable shell. In this way, a localized adaption of the pressure exerted onto the insert towards the inside of the footwear may be achieved. In particular, the at least one expandable liquid bag may be filled with liquid in such a manner that a different pressure level is reached at the position of the at least expandable liquid bag, as compared to the liquid chamber within the expandable shell. The at least one expandable liquid bag may be used in a number of ways. For example, a higher liquid pressure may be used for pressing the insert harder against the inside of the footwear in positions where an attachment between the insert and the footwear is difficult. A lower pressure in the at least one expandable liquid bag may be used for reducing the stress on sensitive portions of the inside of the footwear. The at least one expandable liquid bag may be smaller in volume than the liquid chamber, in particular less than 20%, further in particular less than 10%, in volume of the liquid chamber. In this way, the liquid in the at least one expandable liquid bag may be more locally constrained than the liquid in the liquid chamber. The liquid in the at least one expandable liquid bag may be prevented from flowing to portions of the footwear where the footwear yields most easily. The expandable liquid bag may be seen as an additional bladder/balloon, in particular an additional bladder/balloon provided on the outside/inside of the expandable shell.
According to a further embodiment, the expandable last further comprises at least one ancillary liquid port, providing liquid communication between the at least one expandable liquid bag and at least one external liquid source. Said at least one external liquid source may be one or more separate liquid sources or may be/contain the same external liquid source, as used for the liquid chamber within the expandable shell. With the at least one ancillary liquid port and the one or more separate external liquid sources, if present, the at least one expandable liquid bag may be used for flexibly controlling the pressure therein, as compared to the pressure within the liquid chamber within the expandable shell.
According to a further embodiment, the expandable last further comprises at least one ancillary liquid supply line, coupling the at least one expandable liquid bag to the at least one ancillary liquid port. In this way, the at least one expandable liquid bag may perform its desired function with a low liquid bag volume, with the ancillary liquid supply line(s) achieving the liquid transfer between the ancillary liquid port(s) and the expandable liquid bag(s). The at least one expandable liquid supply line may run through the liquid chamber within the expandable shell. However, it is also possible that the at least one ancillary liquid supply line runs along the outside of the expandable shell.
According to a further embodiment, the at least one expandable liquid bag comprises: an expandable liquid bag at an instep portion of the expandable shell; an expandable liquid bag at a toe portion of the expandable shell; an expandable liquid bag in a forefoot portion of the expandable shell; an expandable liquid bag in an upper midfoot portion of the expandable shell. The expandable liquid bag at an instep portion of the expandable shell may be arranged on an outside or on an inside of the expandable shell. The expandable liquid bag at a toe portion of the expandable shell may be arranged on an outside or on an inside of the expandable shell. The expandable liquid bag in a forefoot portion of the expandable shell may be arranged in the forefoot portion of the expandable shell in such a manner that it abuts the expandable shell upon expansion. The expandable liquid bag in the upper midfoot portion of the expandable shell may be arranged in the midfoot portion in such a manner that it abuts the expandable shell upon expansion. With the expandable liquid bag at an instep portion of the expandable shell and/or with the expandable liquid bag in an upper midfoot portion of the expandable shell, the insert may be effectively pressed against the inside of the footwear at a tongue portion thereof. An attachment between the insert and the tongue portion of the footwear, which may be difficult due to the particular nature of tongue constructions, may be achieved in an effective manner. With the expandable liquid bag at a toe portion of the expandable shell and/or with the expandable liquid bag in a forefoot portion of the expandable shell, the insert may be effectively pressed against the footwear at a toe portion thereof. An attachment between the insert and the toe portion of the footwear, which may be difficult due to the irregularities of the inner contour in the toe portion and/or due to the comparably stiff nature the toe portion of the footwear, which may act to push the liquid to other portions of the expandable shell, may be achieved in an effective manner.
According to a further embodiment, the at least one expandable liquid bag is at least partly filled with an open-cell foam, in particular with an open-cell polyurethane foam, and/or with a spacer fabric. When filled with liquid, the at least one expandable liquid bag may have a larger extension than the open-cell foam/the spacer fabric. The spacer fabric may be particularly suitable for an expandable liquid bag that has a somewhat flat shape, such as an expandable liquid bag arranged at an instep portion of the expandable shell.
According to a further embodiment, the expandable last further comprises a lid, to which the core support element and the expandable shell are mounted. The lid provides for an effective way to fix a positional relationship between the core support element and the expandable shell, while still allowing the two elements to move with respect to each other in portions thereof. While the positional relationship between the core support element and the expandable shell may be fixed at one end thereof, the expandable shell is free to expand and move away from the core support element over a large portion thereof. When the last is inserted into the footwear and the footwear is placed on a table or other horizontal structure in its normal use orientation, the core support element and the expandable shell extend downwards from the lid. In this way, the lid may form an upper end portion of the expandable last, when inserted into the footwear in a normal shoe orientation. This explanation of the relative position of the lid and the core support element/expandable shell does not preclude the lid to be a side portion or a lower portion of the expandable last, when used for furnishing footwear with an insert. In other words, the expandable last may be positioned upside down, i.e. lid down, at selected times or during substantially the entire operation of providing the footwear with the insert.
According to a further embodiment, the liquid port is arranged in the lid. In this way, the lid is also the structure of the expandable last that provides for the connection point to the external liquid source. In particular, the liquid port may be arranged in the lid in such a manner that the external liquid source/an external liquid supply line may be attached to the lid. The liquid port may extend through the lid.
According to a further embodiment, the lid has an extension substantially corresponding to a transverse cross-section of the collar of the footwear. In this way, the lid may have a sufficient extension for mounting the core support element, the expandable shell and, if desired, the liquid port thereto. Also, the expandable shell may be mounted to the lid around a peripheral region thereof. In this way, the expandable shell may immediately engage with the insert on the inside of the footwear upon receiving liquid in the liquid chamber.
According to a further embodiment, the expandable last further comprises a heater configured to heat the liquid in the liquid chamber and/or to heat the expandable shell. By heating the liquid and/or the expandable shell, the heater may contribute to the expansion of the liquid and/or may provide a warming/heating of the insert. Such warming/heating of the insert may help in positioning the insert by making the same more pliable and/or may help in attaching the insert to the inside of the footwear, for example by activating a heat-activated adhesive on the insert. The heater may be an electric heater that may have a power supply line to an external power source. The heater may also have a rechargeable power source, such as a rechargeable battery, which may allow the heater to at least temporarily operate without being coupled to an external power supply.
According to a further embodiment, the expandable last comprises an external heater configured to heat the liquid before being introduced into the liquid chamber. In this way, above described beneficial effects of using heated liquid in the liquid chamber may be achieved, while keeping the core support element/liquid chamber free of heating functionality. The external heater may be arranged at a more easily accessible location and may be designed/operated without the constraints associated with the interior of the footwear.
According to a further embodiment, the expandable last is configured for furnishing the footwear with a waterproof, breathable bootie. In this way, the footwear may be made waterproof with the help of the expandable last. As discussed above, the expandable last may help in making the footwear waterproof at a late stage of the assembly, in particular at a point in time when the collar of the footwear is the only access point to the interior of the footwear. The waterproof, breathable bootie may be embodied in accordance with any of the embodiments, as described in PCT/EP2017/068030 and/or PCT/EP2018/084179, the contents of which are incorporated herein by reference in their entirety.
According to a further embodiment, the expandable last is configured for furnishing the footwear with a waterproof, breathable bootie, wherein the waterproof, breathable bootie is provided, on its outside, with pressure sensitive adhesive and/or heat-activated adhesive for attachment to the inside of the footwear. The pressure sensitive adhesive and/or heat-activated adhesive may be provided on selected portions of the outside of the waterproof, breathable bootie or may be provided substantially all over the outside of the waterproof, breathable bootie. The pressure sensitive adhesive and/or heat-activated adhesive may be provided as a continuous adhesive layer or as an adhesive pattern, such as a dot or stripe pattern. The expandable last may be particularly suitable for inserting the waterproof, breathable bootie provided with adhesive, because the risk of the adhesive getting stuck in undesired positions during the insertion of the expandable last can be kept small by inserting the expandable last in an un-expanded state together with the waterproof, breathable bootie. It is pointed out that it is also possible to insert the waterproof, breathable bootie into the footwear with a separate device and to subsequently use the expandable last for exerting the pressure onto the insert towards an inside of the footwear. Further, the attachment between the waterproof, breathable bootie and the inside of the footwear may be supplemented with an adhesive tape in a collar region of the footwear. An adhesive tape in the collar region of the footwear may also provide for a clean finish, blocking the upper edge of the insert from view and preventing delamination of a multi-layer insert from the upper edge. The term heat-activated adhesive refers to an adhesive that has the capacity to be activated by heat. The heat-activated adhesive may also be referred to as heat-activatable adhesive.
Exemplary embodiments of the invention further include an expandable last for furnishing footwear with an insert, comprising: an expansion assembly; an expandable shell, arranged around the expansion assembly; and a liquid chamber within the expandable shell; wherein the expandable last is insertable into the footwear through a collar of the footwear and wherein the expandable shell is configured to expand for pressing the insert towards an inside of the footwear; and wherein the expansion assembly is configured to adapt its extension for exerting localized pressure onto the expandable shell towards the inside of the footwear. Exemplary embodiments of the expandable last, having an expansion assembly and an expandable shell, provide an alternative tool for effectively furnishing footwear with an insert, as compared to above described exemplary embodiments, having a form-stable core support element and an expandable shell. Above described additional features, modifications, and effects are applicable to the expandable last, having an expansion assembly and an expandable shell, in an analogous manner, as long as they are not conceptually excluded by the expansion assembly.
According to exemplary embodiments of the invention, the expandable last comprises an expansion assembly and an expandable shell, arranged around the expansion assembly. In this way, the expandable last may combine a localized exertion of pressure onto particular portions of the expandable shell via the expansion assembly with a more uniform exertion of pressure onto the insert via the liquid in the liquid chamber. A good compromise between uniform exertion of pressure and localized exertion of pressure may be achieved. Also, the localized exertion of pressure may achieve a pre-shaping of the expandable shell and may thus allow for a particularly good positioning of the insert with respect to the inside of the footwear. Further, the expansion assembly may also provide for core support to the expandable last.
According to a further embodiment, the expansion assembly comprises at least one of a hydraulically operated piston, a pneumatically operated piston, an electrically operate piston, and a spring-loaded piston for exerting the localized pressure. With each of the hydraulically operated piston, the pneumatically operated piston, and the electrically operated piston, an active and highly granular exertion of localized pressure may be possible. With the spring-loaded piston, an external control and power supply may be dispensed with and an effective exertion of localized pressure may be achieved with comparably less complexity. In particular, the spring-loaded piston may allow for the expansion assembly to exert localized pressure without a complex interaction between the piston and an external control/power entity.
According to a further embodiment, the expansion assembly comprises a base plate, to which said at least one of a hydraulically operated piston, a pneumatically operated piston, an electrically operated piston, and a spring-loaded piston is mounted. In this way, the piston may have a well-defined travel path with respect to the base plate, which in turn may allow for a well-defined travel path with respect to the footwear. The base plate may allow for a well-defined arrangement/positioning of the expansion assembly within the footwear.
According to a further embodiment, the spring-loaded piston comprises at least one of a coil spring and a gas spring. In particular, the spring-loaded piston may comprise a coil spring or a gas spring.
According to a further embodiment, the expansion assembly is configured to exert localized pressure onto at least one of a toe portion and a heel portion of the expandable shell. In this way, the expansion assembly may be particularly suitable for exerting localized pressure in the front and/or the rear of the expandable shell. This in turn may allow for achieving a good longitudinal positioning, stretching, and/or attaching of the insert to the inside of the footwear. The expansion assembly may thus work similar to a shoe tree and may ensure that the insert is arranged over the full length of the inside of the footwear.
According to a further embodiment, the expansion assembly comprises a spring skeleton having a forefoot spring portion, configured to exert localized pressure onto at least one of a toe portion and an instep portion of the expandable shell and having a heel spring portion, configured to exert localized pressure onto a heel portion of the expandable shell. With the spring skeleton, localized pressure may be exerted onto crucial portions of the insert in a particularly effective manner. The spring skeleton may be an elastic spring structure, resembling a foot outline/a foot skeleton in its longitudinal direction. The expandable shell may be conformed to some extent to the general shape of a human foot, while leaving ample room for the liquid within the expandable shell to provide for uniform exertion of pressure onto the expandable shell. Again, a good compromise between uniform exertion of pressure and localized exertion of pressure may be achieved. The spring skeleton may work similar to a shoe tree and may provide a desired stretching of the expandable shell at the toe portion and/or the instep portion and/or the heel portion of the expandable shell.
According to a further embodiment, the spring skeleton is made of metal, in particular made of steel. According to an alternative embodiment, the spring skeleton is made of composite material, in particular made of fiber-reinforced plastics material. The spring skeleton may be made from an elastic synthetic material. It may also be made from a memory alloy or bimetal. It is also possible that the spring skeleton is made from a combination of parts of different materials, in particular from a combination of metal parts and composite material parts. Further, it is possible that pressure exertion pads are provided at the spring skeleton for exerting the localized pressure. The pressure exertion pads may be made from a different material, such as from a plastics material, in particular a plastics material that is softer than the material of the spring skeleton, or from a padding material.
According to a further embodiment, the forefoot spring portion is configured to force its forefoot end portion in a forward and upward direction. In this way, a particularly good stretching of the insert and/or a particularly good attachment between the insert and the toe portion of the footwear, which may be difficult due to the irregularities of the inner contour in the toe portion and/or due to the comparably stiff nature of the toe portion of the footwear, may be achieved in an effective manner. The upward component of the force, exerted by the forefoot end portion of the forefoot spring portion, may be particularly effective in achieving an overall strong attachment between the insert and the toe portion of the footwear.
According to a further embodiment, the forefoot spring portion has a waved shaped, with a first exposed portion exerting localized pressure onto the instep portion of the expandable shell and with a second exposed portion exerting localized pressure onto the toe portion of the expandable shell. The waved shaped of the forefoot spring portion provides for a particular effective way of exerting localized pressure onto both the toe portion of the expandable shell and the instep portion of the expandable shell. With the waved shape, a balanced exertion of localized pressure between the instep portion and the toe portion of the expandable shell may be achieved. The waved shape may be particularly well-suited for providing localized pressure in the forefoot portion of the expandable last. The second exposed portion may in particular be the forefoot end portion, as described above, and may in particular be configured as being forced in a forward and upward direction.
According to a further embodiment, the forefoot spring portion comprises an instep spring element, extending along the instep portion of the expandable shell and having its free end pointing rearwards. The instep spring element may in particular extend along the instep portion of the expandable shell and may have its free end pointing in a rearward and upward direction. With such a dedicated instep spring element, localized pressure may be exerted particularly well onto the instep portion of the expandable shell. While the instep spring element is seen as part of the forefoot spring portion, it is an element that extends away from that part of the forefoot spring portion that extends between a collar region of the expandable last and the forefoot end portion of the forefoot spring portion. Via this extending away, the instep spring element has a free end pointing rearwards. With the instep spring element having its free end pointing rearwards, the forefoot spring portion may be effectively designed to provide the localized pressure onto the toe portion of the expandable shell and to provide the localized pressure onto the instep portion of the expandable shell in a highly targeted manner, taking into account the particulars of the toe portion and the instep portion in a particularly effective manner.
According to a further embodiment, the heel spring portion is configured to force its heel end portion in a rearward and upward direction. In this way, an attachment between the insert and the heel portion of the footwear, which may be difficult due to the particular shape of heel constructions of footwear, may be achieved in an effective manner. In particular, the upward component of the force of the heel end portion towards the expandable shell/towards the insert may be particularly effective in contributing to said attachment.
According to a further embodiment, the expansion assembly comprises a form-stable core support element. The form-stable core support element may in particular be substantially L-shaped or substantially T-shaped. The form-stable core support element may provide for enhanced stability for the spring skeleton of the expansion assembly. The form-stable core support element may in particular reach to a sole portion of the expandable shell. It may thus provide an effective positioning of the expandable shell in a downwards portion of the expandable last. In particular, the form-stable core support element may counter potential upward components of the force exerted by the forefoot end portion and/or the heel end portion of the spring skeleton. It may thus contribute to a multi-directional stretching of the expandable shell.
According to a further embodiment, the expandable last further comprises a lid, to which the expandable shell is mounted. In a particular embodiment, the expansion assembly is fixed in position with respect to the lid. For example, the expansion assembly may be mounted to the lid via a mounting rod. In this way, an effective positioning of the expansion assembly with respect to the collar of the footwear may be achieved. Also, core support to the expandable last may be achieved in an effective manner, similar to the core support element, discussed above.
According to a further embodiment, the spring skeleton is mounted to the lid. It is also possible that the spring skeleton is mounted to a core support element, which is in turn mounted to the lid. It is also possible that both the spring skeleton and a core support element are mounted to the lid.
According to a further embodiment, the expansion assembly is attached to the expandable shell. In this case, the expansion assembly may be un-attached to the lid or may be attached to the lid in addition to the attachment to the expandable shell. The attachment between the expansion assembly and the expandable shell may provide for a particularly well-defined exertion of localized pressure by the expansion assembly.
According to a further embodiment, the expandable last further comprises a liquid port, providing liquid communication between the liquid chamber and an external liquid source, wherein the expandable shell is configured to expand for pressing the insert towards an inside of the footwear, when receiving liquid in the liquid chamber via the liquid port. In this way, in addition to the localized pressure exerted by the expansion assembly, the more uniform pressure via the liquid chamber is provided via the reception of liquid from an external liquid source.
According to a further embodiment, the expandable last further comprises a heater arranged in the liquid chamber, wherein the heater is configured to heat liquid in the liquid chamber for expanding the expandable shell and pressing the insert towards an inside of the footwear via an increase in volume of the liquid in the liquid chamber. In this way, in addition to the localized pressure exerted by the expansion assembly, the more uniform pressure via the liquid chamber is provided by an increase in volume of the liquid due to the heating thereof. In this way, the exertion of the more uniform pressure may be achieved without a liquid port and without increasing the amount of liquid in the liquid chamber.
According to a further embodiment, the heater is an electric heater. The electric heater may be coupled to an external power supply via a power supply line. The power supply line may run through the lid. It is also possible that the heater comprises a rechargeable power source, such as a rechargeable battery.
According to a further embodiment, the expansion assembly and the heater are fixed in position with respect to each other. In a particular embodiment, the expansion assembly and the heater are formed as an integrated structural unit. In this way, the expandable last may have a high degree of inherent stability and may be handled in a particularly convenient manner.
According to a further embodiment, the expandable last further comprises a lid, to which the expandable shell is mounted. The expansion assembly and/or the heater may also be mounted to the lid. In particular, the expansion assembly and the heater may be mounted to the lid as an integrated structural unit.
According to a further embodiment, the expandable shell and the lid form a liquid-tight enclosure. In particular, the lid and the expandable shell may be free of a liquid port. The lid and the expandable shell being free of a liquid port is to be understood in a way that no liquid communication between the liquid chamber and an outside of the expandable last takes place in the expansion operation, i.e. during the application of pressure to the insert via the expandable shell. The liquid-tight enclosure may keep the amount of liquid within the liquid chamber fixed, and the expansion of the expandable shell may be solely caused by the heating of the liquid within the liquid chamber. This does not exclude the provision of suitable means for filling and evacuating liquid into/from the liquid chamber between such normal operations. For example, the liquid may be exchanged after a certain number of expansion operations, e.g. for cleaning, maintaining the heater, for preventing liquid depositions on the expandable shell, etc.
According to a further embodiment, the expandable last may be combined with an external heater, such as an electric oven or microwave oven. In particular, an embodiment of the invention may be the combination of the expandable last and an external heater, into which the expandable last may be placed together with the footwear. In this way, the expandable last and the footwear may be jointly heated, and the heating action, described above with respect to the heater within the expandable last, may take place as a result of the external heating.
The expandable last, having an expansion assembly and an expandable shell, as described with respect to any of the embodiments above, may additionally have any of the following features, alone or in any combination:
The liquid chamber comprises substantially the entire volume between the expansion assembly and the expandable shell.
The expandable shell is elastic, in particular made from latex material.
The expandable shell has, at least in one or more regions thereof, dimension-specific elastic properties.
The liquid chamber is at least partly filled with an open-cell foam, in particular with an open-cell polyurethane foam, and/or with a spacer fabric.
The expandable last further comprises at least one expandable liquid bag, arranged outside or inside of the expandable shell.
The expandable last further comprises at least one ancillary liquid port, providing liquid communication between the at least one expandable liquid bag and at least one external liquid source.
The expandable last further comprises at least one ancillary liquid supply line, coupling the at least one expandable liquid bag to the at least one ancillary liquid port, wherein the at least one ancillary liquid supply line in particular runs through the liquid chamber.
The at least one expandable liquid bag comprises at least one of: an expandable liquid bag at an instep portion of the expandable shell; an expandable liquid bag at a toe portion of the expandable shell; an expandable liquid bag in a forefoot portion of the expandable shell; an expandable liquid bag in an upper midfoot portion of the expandable shell.
The at least one expandable liquid bag is at least partly filled with an open-cell foam, in particular with an open-cell polyurethane foam, and/or with a spacer fabric.
The liquid port is arranged in the lid.
The lid has an extension substantially corresponding to a transverse cross-section of the collar of the footwear.
Exemplary embodiments of the invention further include an expandable last for furnishing footwear with an insert, comprising: an expandable shell; a liquid chamber within the expandable shell; and a liquid port, providing liquid communication between the liquid chamber and an external liquid source; wherein the expandable last is insertable into the footwear through a collar of the footwear and wherein, when receiving liquid in the liquid chamber via the liquid port, the expandable shell is configured to expand for pressing the insert towards an inside of the footwear; and wherein the expandable shell has, at least in one or more regions thereof, dimension-specific elastic properties. Exemplary embodiments of the expandable last, whose expandable shell has dimension-specific elastic properties, provide an alternative tool for effectively furnishing footwear with an insert, as compared to above described exemplary embodiments of expandable lasts. Above described additional features, modifications, and effects are applicable to the expandable last, whose expandable shell has dimension-specific elastic properties, in an analogous manner, as long as they are not conceptually excluded by the expandable shell having dimension-specific elastic properties.
With the expandable shell having dimension-specific elastic properties, the course of expansion of the expandable shell can be controlled and a particularly effective exertion of pressure onto the insert may be achieved. For example, the dimension-specific elastic properties may allow for the expandable shell to first assume a desired coarse shape, before exerting a highly uniform pressure onto the insert. By having dimension-specific elastic properties, the expandable shell reacts to pressure increases differently in at least two dimensions. The dimensions may be dimensions defined in a cartesian coordinate system or may be dimensions suitably defined in the context of a substantially foot-shaped last, such as a longitudinal dimension of the expandable shell and a circumferential dimension of the expandable shell.
According to a further embodiment, the expandable shell has dimension-specific elastic properties in at least one of a midfoot portion and a forefoot portion of the expandable shell. In this way, a particularly good adaptation to the footwear shape may be achieved. Also, a good adaptation to footwear of different sizes may be achieved. In this way, the expandable last may be used for footwear of considerably different sizes.
According to a further embodiment, the expandable shell is configured to expand more easily in a longitudinal dimension than a circumferential dimension in at least one of a midfoot portion and a forefoot portion. In this way, the expandable shell may first expand in the longitudinal dimension, before expanding in the circumferential dimension. This in turn may allow for the expandable last to first cover the full length of the longitudinal dimension of the footwear, before exerting pressure around the circumference of the expandable last. Such a behaviour may help in positioning the insert/keeping the insert in position in a particularly targeted manner, before applying all around pressure. The terminology of the expandable shell being configured to expand more easily in the longitudinal dimension than in the circumferential dimension means that the expandable shell expands in the longitudinal dimension earlier and/or at a lower fluid pressure than in the circumferential dimension.
According to a further embodiment, the expandable last is free of a form-stable core support element and/or free of an expansion assembly, arranged within the expandable shell. In other words, the exertion of pressure onto the insert may be achieved solely by the provision of an expandable shell with dimension-specific elastic properties and the building-up of pressure within the liquid chamber via liquid received through the liquid port.
The expandable last, having an expandable shell with dimension-specific elastic properties, as described with respect to any of the embodiments above, may additionally have any of the following features, alone or in any combination:
The liquid chamber comprises substantially the entire volume within the expandable shell.
The expandable shell is made from latex material.
The liquid chamber is at least partly filled with an open-cell foam, in particular with an open-cell polyurethane foam, and/or with a spacer fabric.
The expandable last further comprises at least one expandable liquid bag, arranged outside or inside of the expandable shell.
The expandable last further comprises at least one ancillary liquid port, providing liquid communication between the at least one expandable liquid bag and at least one external liquid source.
The expandable last further comprises at least one ancillary liquid supply line, coupling the at least one expandable liquid bag to the at least one ancillary liquid port, wherein the at least one ancillary liquid supply line in particular runs through the liquid chamber.
The at least one expandable liquid bag comprises at least one of: an expandable liquid bag at an instep portion of the expandable shell; an expandable liquid bag at a toe portion of the expandable shell; an expandable liquid bag in a forefoot portion of the expandable shell; an expandable liquid bag in an upper midfoot portion of the expandable shell.
The at least one expandable liquid bag is at least partly filled with an open-cell foam, in particular with an open-cell polyurethane foam, and/or with a spacer fabric.
The expandable last further comprises a lid, to which the expandable shell is mounted.
The liquid port is arranged in the lid.
The lid has an extension substantially corresponding to a transverse cross-section of the collar of the footwear.
The expandable last further comprises a heater, configured to heat the liquid in the liquid chamber and/or to heat the expandable shell.
Exemplary embodiments of the invention further include an expandable last for furnishing footwear with an insert, comprising: a rigid last portion; an expandable shell, arranged adjacent to the rigid last portion; a liquid chamber within the expandable shell; and a liquid port, providing liquid communication between the liquid chamber and an external liquid source; wherein the expandable last is insertable into the footwear through a collar of the footwear and wherein, when receiving liquid in the liquid chamber via the liquid port, the expandable shell is configured to expand for pressing the insert towards an inside of the footwear. Exemplary embodiments of the expandable last, having a rigid last portion and an expandable shell adjacent to the rigid last portion, provide an alternative tool for effectively furnishing footwear with an insert, as compared to above described exemplary embodiments of expandable lasts. Above described additional features, modifications, and effects are applicable to the expandable last, having a rigid last portion and an expandable shell adjacent to the rigid last portion, in an analogous manner, as long as they are not conceptually excluded by the combination of the rigid last portion and the expandable shell.
According to exemplary embodiments of the invention, the expandable last comprises a rigid last portion and an expandable shell, arranged adjacent to the rigid last portion. The rigid last portion may provide for an effective exertion of pressure in portions of the footwear where good results may be achieved with a rigid structure. In turn, the expandable shell may have smaller extensions and may thus provide the desired highly uniform pressure with a lower amount of liquid. The flexibility of the expandable shell may be combined with the low complexity of a rigid last portion in a beneficial manner.
The expandable last may also comprise a plurality of rigid last portions and/or a plurality of expandable shells. The additional features and modifications, as described herein, are applicable to one or a subset or all of the plurality of rigid last portions and/or to one or a subset of all of the plurality of expandable shells.
According to a further embodiment, the rigid last portion is made from metal, such as aluminum. Metal may provide for a highly rigid structure of the last portion and may be a good heat conductor, in case the rigid last portion is heated and/or in case the liquid in the liquid chamber is heated. Aluminum provides for a good compromise between the beneficial properties of metal and a comparably low weight. The rigid last portion may also be made from other suitable materials, such as heat resistant plastic.
According to a further embodiment, the rigid last portion is heatable. In this way, the rigid last portion may be used for heating the liquid in the liquid chamber of the expandable last and may thus contribute to the expansion of the expandable shell. Also, the rigid last portion may apply heat to the insert and may thus help in attaching the insert to the inside of the footwear, for example by activating a heat-activated adhesive on the insert. In addition/alternatively, the rigid last portion may be thermally conductive, being configured to conduct heat to the insert from heated liquid in the liquid chamber.
According to a further embodiment, the expandable last comprises a rigid forefoot and instep last portion and a rigid heel last portion, wherein the expandable shell is arranged between the rigid forefoot and instep last portion and the rigid heel last portion. In this way, the expandable last comprises a so-called split last, having a front rigid last portion and a rear rigid last portion. The space between the rigid forefoot and instep last portion and the rigid heel last portion may be partly or substantially entirely filled with the expandable shell, at least when in an expanded state. In this way, a highly uniform pressure may be applied to a midfoot portion and/or ankle portion of the inside of the footwear, while the front and rear rigid last portions exert pressure onto the forefoot portion and the heel portion of the inside of the footwear.
According to a further embodiment, the rigid forefoot and instep last portion and the rigid heel last portion are movable with respect to each other and the expandable last comprises an actuator for controlling a spacing between the rigid forefoot and instep last portion and the rigid heel last portion. In this way, the expandable last may be adapted to the footwear in question, in particular adapted to the shoe size of the footwear in question. Further, the expandable last may be controlled to exert a desired pressure onto the front portion and the heel portion of the inside of the footwear in this manner. Also, the insertion of the expandable last into the footwear may be carried out in a particularly convenient manner, when the rigid forefoot and instep last portion and the rigid heel last portion have a low spacing therebetween. The actuator may be a pneumatic actuator or a hydraulic actuator or an electric actuator.
According to a further embodiment, the expandable last comprises at least one expandable liquid bag, arranged on an outside of the rigid last portion. As discussed above, a localized adaption of the pressure exerted onto the insert towards the inside of the footwear may be achieved in this manner.
According to a further embodiment, the at least one expandable liquid bag comprises at least one expandable liquid bag in a toe region and/or in a heel region of the expandable last, in particular an expandable liquid bag in a toe region of the rigid forefoot and instep last portion of the expandable last. The term toe region may refer to an upper side of the toe region of the expandable last or to a lower side of the toe region of the expandable last or to a joint upper and lower side of the toe region, reaching around the tip of the expandable last.
The expandable last, having a rigid last portion and an expandable shell, arranged adjacent to the rigid last portion, as described with respect to any of the embodiments above, may additionally have any of the following features, alone or in any combination:
The liquid chamber comprises substantially the entire volume within the expandable shell.
The expandable shell is elastic, in particular made from latex material.
The expandable shell has, at least in one or more regions thereof, dimension-specific elastic properties.
The liquid chamber is at least partly filled with an open-cell foam, in particular with an open-cell polyurethane foam, and/or with a spacer fabric.
The expandable last further comprises at least one ancillary liquid port, providing liquid communication between the at least one expandable liquid bag and at least one external liquid source.
The expandable last further comprises at least one ancillary liquid supply line, coupling the at least one expandable liquid bag to the at least one ancillary liquid port, wherein the at least one ancillary liquid supply line in particular runs through the liquid chamber.
The at least one expandable liquid bag is at least partly filled with an open-cell foam, in particular with an open-cell polyurethane foam, and/or with a spacer fabric.
The expandable last further comprises a lid, to which the expandable shell is mounted.
The liquid port is arranged in the lid.
Exemplary embodiments of the invention further include an expandable last for furnishing footwear with an insert, comprising: an expandable shell; a granulate chamber within the expandable shell; and a granulate port, providing a granulate channel between the granulate chamber and an external granulate source; wherein the expandable last is insertable into the footwear through a collar of the footwear and wherein, when receiving granulate in the granulate chamber via the granulate port, the expandable shell is configured to expand for pressing the insert towards an inside of the footwear. The granulate port may in particular be configured for providing a granulate channel between the granulate chamber and an external heated granulate source. Exemplary embodiments of the expandable last, having a granulate chamber within an expendable shell and a granulate port for receiving granulate within the granulate chamber, provide an alternative tool for effectively furnishing footwear with an insert, as compared to above described exemplary embodiments of expandable lasts. Above described additional features, modifications and effects are applicable to the expandable last, having a granulate chamber within an expandable shell, in an analogous manner, as long as they are not conceptually excluded by the combination of the granulate chamber and the expandable shell.
With the granulate chamber within the expandable shell and the granulate port, the expandable last may be conveniently introduced into the interior of the footwear and the expandable shell may exert pressure onto the insert with a high degree of uniformity upon receiving granulate within the granulate chamber. Relying on granulate for exerting pressure onto the insert with a high degree of uniformity, the expandable last may work similar to above described expandable lasts, without relying on liquid as the pressure exerting medium. In this way, the footwear may be kept free of damage, in case the expandable shell is punctured or torn during the furnishing of the footwear with an insert, as described herein. Heated granulate, for example received from an external heated granulate source, may help in attaching the insert to the inside of the footwear, for example by activating a heat-activated adhesive on the insert.
The expandable last, having a granulate chamber within an expandable shell, as described with respect to any of the embodiments above, may additionally have any of the following features, alone or in any combination:
The granulate chamber comprises substantially the entire volume within the expandable shell.
The expandable shell is elastic.
The expandable shell is made from latex material.
The expandable shell is made of synthetic material, in particular of a textile material. The expandable shell may for example by a nylon sock.
The expandable shell has, at least in one or more regions thereof, dimension-specific elastic properties.
The expandable last further comprises at least one expandable liquid bag, arranged outside or inside of the expandable shell.
The expandable last further comprises at least one ancillary liquid port, providing liquid communication between the at least one expandable liquid bag and at least one external liquid source.
The expandable last further comprises at least one ancillary liquid supply line, coupling the at least one expandable liquid bag to the at least one ancillary liquid port, wherein the at least one ancillary liquid supply line in particular runs through the granulate chamber.
The at least one expandable liquid bag comprises at least one of: an expandable liquid bag at an instep portion of the expandable shell; an expandable liquid bag at a toe portion of the expandable shell; an expandable liquid bag in a forefoot portion of the expandable shell; an expandable liquid bag in an upper midfoot portion of the expandable shell.
The at least one expandable liquid bag is at least partly filled with an open-cell foam, in particular with an open-cell polyurethane foam, and/or with a spacer fabric.
The granulate port is arranged in the lid.
The lid has an extension substantially corresponding to a transverse cross-section of the collar of the footwear.
The expandable last further comprises a heater, configured to heat the granulate in the granulate chamber and/or to heat the expandable shell.
The expandable last further comprises a form-stable core support element, in particular a substantially L-shaped or substantially T-shaped core support element.
It is also possible that the granulate is introduced into the insert without an interposed expandable shell. The granulate may be introduced into the insert, before the insert is placed within the footwear and/or when the insert is positioned in the footwear, and an exertion of pressure onto the insert may be achieved via controlling the amount of granulate within the insert and/or the temperature of the granulate.
Exemplary embodiments of the invention further include a method for furnishing footwear with an insert using an expandable last, as described herein. The expandable last may be embodied in accordance with any of the embodiments, described above. The additional features, modifications, and effects, described above with respect to the expandable last, apply to the method for furnishing footwear with an insert in an analogous manner.
According to a further embodiment, the insert is a waterproof, breathable bootie. In this way, the method for furnishing footwear with an insert may also be referred to as a method for waterproofing footwear.
Exemplary embodiments of the invention further include a method for furnishing footwear with an insert, the method comprising: inserting an expandable last into the footwear through a collar of the footwear, the expandable last having an expandable shell and a liquid chamber within the expandable shell; and pressing the insert towards an inside of the footwear by expanding the expandable shell via liquid in the liquid chamber. The additional features, modifications, and effects, described above with respect to the expandable last, apply to the method for furnishing footwear with an insert in an analogous manner. In particular, the expandable last may be embodied in accordance with any of the embodiments described above.
According to a further embodiment, said expanding of the expandable shell via liquid in the liquid chamber comprises introducing liquid into the liquid chamber. In particular, the liquid may be introduced via a liquid port in the expandable last from an external liquid source. Any suitable liquid may be used for expanding the expandable shell. Suitable liquids include water, oils, and thermotransfer fluids, such as 3M Novec 7500®.
According to a further embodiment, said expanding of the expandable shell via liquid in the liquid chamber comprises introducing heated liquid into the liquid chamber. In particular, the liquid may be introduced at a temperature between 60° C. and 200° C. The temperature may depend on the liquid used. For example, water may be introduced at a temperature of between 60° C. and 95° C. The term heated liquid may refer to liquid being warmer than room temperature, in particular liquid having at least 30° C.
According to a further embodiment, said expanding of the expandable shell via liquid in the liquid chamber comprises heating the liquid in the liquid chamber. In particular, the liquid may be heated via a heater arranged within the expandable shell.
According to a further embodiment, the insert is a waterproof, breathable bootie. In this way, the method for furnishing footwear with an insert may also be referred to as a method for waterproofing footwear.
According to a further embodiment, the inserting of the expandable last into the footwear through a collar of the footwear comprises inserting the expandable last into an inner space of the footwear, after the inner space of the footwear has been closed, e.g. after the footwear has been lasted and the sole has been applied. The inserting of the expandable last into the footwear may take place when the footwear is otherwise fully assembled or substantially fully assembled.
According to a further embodiment, the pressing of the insert towards the inside of the footwear comprises attaching/adhering the insert to the inside of the footwear.
Exemplary embodiments of the invention further include a method for furnishing footwear with an insert, the method comprising: inserting an expandable last into the footwear through a collar of the footwear, the expandable last having an expandable shell and a granulate chamber within the expandable shell; and pressing the insert towards an inside of the footwear by expanding the expandable shell via granulate in the granulate chamber. The additional features, modifications, and effects, described above with respect to the expandable last and with respect to the method for furnishing footwear with an insert by expanding the expandable shell via liquid, apply to the method for furnishing footwear with an insert by expanding the expandable shell via granulate in an analogous manner. In particular, the expandable last may be embodied in accordance with any of the embodiments described above.
It is pointed out that exemplary embodiments of the expandable last, as described herein, may also be used for other purposes than furnishing footwear with an insert. In particular, the expandable last may also be used at an earlier stage in the production of footwear. For example, the expandable last according to exemplary embodiments of the invention may be used for lasting a shoe upper thereon. The expandable lasts in accordance with the following definitions also form part of the subject matter of the present invention.
Exemplary embodiments of the invention further include an expandable last, comprising: a form-stable core support element; an expandable shell, arranged around the core support element; a liquid chamber within the expandable shell; and a liquid port, providing liquid communication between the liquid chamber and an external liquid source; wherein, when receiving liquid in the liquid chamber via the liquid port, the expandable shell is configured to expand.
Exemplary embodiments of the invention further include an expandable last, comprising: an expansion assembly; an expandable shell, arranged around the expansion assembly; and a liquid chamber within the expandable shell; wherein the expandable shell is configured to expand; and wherein the expansion assembly is configured to adapt its extension for exerting localized pressure onto the expandable shell.
Exemplary embodiments of the invention further include an expandable last, comprising: an expandable shell; a liquid chamber within the expandable shell; and a liquid port, providing liquid communication between the liquid chamber and an external liquid source; wherein, when receiving liquid in the liquid chamber via the liquid port, the expandable shell is configured to expand; and wherein the expandable shell has, at least in one or more regions thereof, dimension-specific elastic properties.
Exemplary embodiments of the invention further include an expandable last, comprising: a rigid last portion; an expandable shell, arranged adjacent to the rigid last portion; a liquid chamber within the expandable shell; and a liquid port, providing liquid communication between the liquid chamber and an external liquid source; wherein, when receiving liquid in the liquid chamber via the liquid port, the expandable shell is configured to expand.
Exemplary embodiments of the invention further include an expandable last, comprising: an expandable shell; a granulate chamber within the expandable shell; and a granulate port, providing a granulate channel between the granulate chamber and an external granulate source; wherein the expandable last is insertable into the footwear through a collar of the footwear and wherein, when receiving granulate in the granulate chamber via the granulate port, the expandable shell is configured to expand for pressing the insert towards an inside of the footwear.
The additional features, modifications, and effects, described above with respect to exemplary embodiments of the expandable last in the context of furnishing footwear with an insert, apply to the exemplary embodiments of the expandable last of the preceding five paragraphs in an analogous manner.
Further exemplary embodiments of the invention will be described below with reference to the accompanying drawings, wherein:
The expandable last 2 comprises a form-stable core support element 4. In the exemplary embodiment of
The expandable last 2 further comprises an expandable shell 6. The expandable shell 6 is arranged around the core support element 4. Between the core support element 4 and the expandable shell 6, a liquid chamber 8 is formed. The expandable shell 6 is made from, for example, a latex material and forms the outermost part of the expandable last 2 for a large portion thereof. In particular, the expandable shell 6 forms the outermost portion of the expandable last 2 in the heel portion, the midfoot portion, the forefoot portion, and part of the ankle portion of the expandable last 2. The expandable shell 6 is elastic and can expand upon receiving liquid in the liquid chamber 8.
In the exemplary embodiment of
The expandable last 2 further comprises a lid 10. The form-stable core support element 4 and the expandable shell 6 are mounted to the lid 10. Together, the expandable shell 6 and the lid 10 fully enclose the core support element 4 and the liquid chamber 8.
The lid 10 is a substantially rotationally symmetric structure, having an inner lid portion 12 and an outer lid portion 14. The lid 10 may be made from plastic or other suitable material. The expandable shell 6 is clamped between the inner lid portion 12 and the outer lid portion 14 in a liquid-tight manner. For additional sealing, a suitable sealing tape, such as a vulcanization tape, may be applied. In this way, no liquid can escape from the liquid chamber 8 through the expandable shell 6 or through its connection to the lid 10. The lid 10 has a transverse cross-sectional extension that substantially corresponds to the transverse extension of the collar of a footwear. In particular, the transverse extension of the lid 10 may correspond to the transverse extension of the collar of the footwear at or above an ankle portion thereof.
The expandable last 2 further comprises a liquid port 16. In the exemplary embodiment of
The core support element 4 comprises a liquid supply line system 20 that is coupled to the liquid port 16. Liquid from the external liquid source may enter the liquid supply line system 20 via the liquid port 16. In the exemplary embodiment of
In use, an insert may be arranged around the expandable shell 6, the expandable last 2 and the insert may be jointly introduced into a footwear, an external liquid source may be coupled to the liquid port 16, liquid, in particular heated liquid may be introduced into the liquid chamber 8 via the liquid port 16 and the liquid supply line system 20, the expandable shell 6 may expand as a response to an increasing amount of liquid in the liquid chamber 8, and the insert may be pressed against the inside of the footwear. A more detailed description of the provision of an insert on the inside of the footwear is given below in
The core support element 4 of the expandable last 2 of
The liquid supply line system 20 of the core support element 4 of
An open-cell foam 24 is arranged around the core support element 4 in the liquid chamber 8. The open-cell foam 24 is a flexible and soft structure that allows for the absorption and passage of liquid. In this way, the open-cell foam may on the one hand absorb liquid and on the other hand pass liquid on towards the expandable shell 6. In the exemplary embodiment of
In the exemplary embodiment of
The expandable last 2 of
The expandable liquid bag 26 is made from elastic material, such as from latex material, and may expand upon receiving liquid via the ancillary liquid port 28 and the ancillary liquid supply line 30. The liquid port 16 and the ancillary liquid port 28 allow for controlling the pressure in the liquid chamber 8 and the pressure in the expandable liquid bag 26 to differ from each other, such that controlled pressure differences between the instep portion of the expandable last 2 and the remainder of the expandable last 2 may be achieved. The liquid port 16 and the ancillary liquid port 28 may be coupled to different external liquid sources. In addition/alternatively, other means for achieving a desired pressure differential between the liquid chamber 8 and the expandable liquid bag 26, such as different valves in the liquid port 16 and the ancillary liquid port 28, may also be provided.
In the exemplary embodiment of
The expandable last 2 of
The expandable last 2 of
In the exemplary embodiment of
Further, a directing element 36, such as a knitted fabric, is provided on the sole side of a front portion of the core support element 4 and on the sole side of the expandable liquid bag 26. The directing element 36 may have the double purpose of holding the sole side of the expandable liquid bag 26 in position with respect to the core support element 4 and of preventing the expandable liquid bag 26 to expand towards the sole side of the expandable shell 6. The contoured engagement surface between the core support element 4 and the expandable liquid bag 26 and the directing element 36 may cooperate to promote the expansion of the expandable liquid bag 26 towards the front of the expandable last 2. The expandable liquid bag 26 may be molded or welded to the core support element 4 or may be attached thereto in any other suitable manner. Also, the directing element 36 may be molded or welded to the core support element 4 and/or to the expandable liquid bag 26. It is also possible that the directing element 36 may be integrated with the expandable liquid bag 26 and/or the core support element 4. For example, the expandable liquid bag 26 and/or the core support element may be molded onto the directing element 36. In that case, the directing element may be partly or fully arranged in the expandable liquid bag 26 and/or the core support element. The directing element 36 may for example be made from PE, PES, or PA.
The expandable liquid bag 26 in the forefoot portion of the expandable shell 6 may be made from any suitable material that is expandable and that can be coupled to the directing element 36. The expandable liquid bag 26 in the forefoot portion of the expandable shell 6 may be made from a bladder structure that has an inherent 3D shape. The expandable liquid bag may for example be made from latex or thermoplastic or adherable plastic compounds, such as Butyl.
Yet further, the expandable last comprises an expandable liquid bag 26 in an upper midfoot portion of the expandable shell 6. The expandable liquid bag 26 is coupled to an external liquid source via a further ancillary liquid port 28 and a further ancillary liquid supply line 30. The expandable liquid bag 26 in the upper midfoot portion of the expandable shell 6 may be partly or entirely filled with a spacer fabric or may be not filled with a spacer fabric. The expandable liquid bag 26 in the upper midfoot portion of the expandable shell 6 contributes to the exertion of suitable pressure onto an instep portion of the insert via the instep portion of the expandable shell 6.
As compared to the expandable lasts of
The expansion assembly 40 comprises a base plate 42 and a spring-loaded piston 44. The base plate 42 is oriented substantially horizontally and is arranged on the inside of the expandable shell 6 at a sole portion thereof. In the exemplary embodiment of
The expansion assembly 40 further comprises a mounting rod 54, which is coupled to the lid 10. Via the mounting rod 54, the expansion assembly 40 is fixed in position with respect to the lid 10. An overall stable arrangement may be achieved, and the expansion assembly may provide core support to the expandable last 2, similar to the core support element 4 described above.
The expandable last 2 of
The expandable last 2 of
The expansion assembly 40 comprises a pneumatic port 48 in the lid 10 and a pneumatic line 50, connecting the pneumatic port 48 and the pneumatically operated piston 46. The pneumatic port 48 has a valve 52. In operation, the extension of the pneumatically operated piston 46 can be controlled via the pneumatic pressure therein, which in turn may be controlled via an external gas source, such as an external air source, coupled to the pneumatic port 48. In this way, the exertion of localized pressure can be controlled with a high degree of granularity.
The expansion assembly 40 of
The expandable last 2 of
The expandable last 2 of
In the exemplary embodiment of
It is pointed out that, instead of/in addition to a heater being provided in the liquid chamber 8, the expandable last may be placed into a heating device, such as an electric oven or a microwave oven, and may then be inserted into the footwear. This heating may also achieve the expansion of the liquid in the liquid chamber 8, and the exertion of pressure onto the insert via the expandable shell 6 may take place via the heated liquid.
The expandable last 2 of
The expandable shell 6 has dimension-specific elastic properties. In the exemplary embodiment of
In particular, the midfoot portion 70 of the expandable shell 6 stretches in a longitudinal dimension 72 at a lower liquid pressure than in a circumferential dimension 74. In this context, the circumferential dimension 74 is defined as extending around the tube-like cross-section of the midfoot portion 70. With the expandable shell 6 thus expanding easier in the longitudinal dimension 72 than in the circumferential dimension 74 in the midfoot portion 70, an increase in liquid pressure leads to an elongation of the midfoot portion 70 along the length of the expandable last 2, before a circumferential expansion and, thus, an increase in cross-section in the midfoot portion 70 takes place. In this way, the expandable last 2 may first adapt to a particular footwear size/length, before exerting a highly uniform all around pressure onto the insert against the inside of the footwear. In a particular exemplary embodiment, the length of the midfoot portion may extend by between 10% and 30%, in particular by about 20%, before the circumferential expansion takes place.
The expandable last 2 of
The rigid forefoot and instep last portion 80 and the rigid heel last portion 82 are movable with respect to each other. The expandable last 2 comprises a pneumatic actuator 84, which is configured to control a spacing between the rigid forefoot and instep last portion 80 and the rigid heel last portion 82. The expandable last 2 further comprises a first gas port 86, equipped with a valve 88, and a second gas port 90, equipped with a valve 92. The first gas port 86 and the second gas port 88 are coupled to the pneumatic actuator 84 via a first gas line 94 and a second gas line 96, respectively. The first gas port 86 and the second gas port 90 are configured to introduce gas into the pneumatic actuator 84 from an external gas source and to release gas from the pneumatic actuator 84, respectively. By an according control of the first gas port 86 and the second gas port 90, the pressure in the pneumatic actuator 84 and, thus, the spacing between the rigid forefoot and instep last portion 80 and the rigid heel last portion 82 may be controlled in a highly accurate manner. The split last may thus be adapted to different footwear sizes/lengths over a wide size/length range.
The expandable last 2 further comprises an expandable shell 6, which has a liquid chamber 8 therein. The expandable last 2 further comprises a liquid port 16, having a valve 18, which is coupled to the liquid chamber 8 via a liquid supply line 20. In operation, liquid may be received in the liquid chamber 8, and the expandable shell 6 may exert a highly uniform pressure onto an insert on the inside of the footwear in those portions of the footwear that are between the rigid forefoot and instep last portion 80 and the rigid heel last portion 82.
The expandable last 2 further comprises an expandable liquid bag 26, arranged around the toe portion of the rigid forefoot and instep last portion 80. The liquid chamber 8 and the expandable liquid bag 26 are coupled via an ancillary liquid supply line 30. The ancillary liquid supply line 30 extends through the rigid forefoot and instep last portion 80. With the expandable liquid bag 26, the pressure exerted onto the insert in a forefoot portion of the footwear may be made more uniform than with the rigid forefoot and instep last portion 80. The expandable liquid bag may balance out sharp contours of the inside of the footwear in the toe portion in a particularly effective manner.
With the combination of the rigid forefoot and instep last portion 80 and the rigid heel last portion 82 on the one hand and the expandable shell 6 and the expandable liquid bag 26 on the other hand, a good compromise between using rigid, comparably straightforward to implement last portions and using expandable last portions, which are highly flexible and well-suited for applying a uniform pressure, may be achieved.
The insert 100 comprises a first glue-covered area 102 around the toe portion of the insert 100, a second glue-covered area 104 around the heel portion of the insert 100, and a third glue-covered area 106 along the collar of the insert 100. In the exemplary embodiment of
The combination of water pressure in the expandable last 2, heat from the water in the expandable last 2, and air pressure in the pressure chamber 140 are a highly effective way for adhering the insert 100 to the inside of the footwear 110. A very stable attachment with a highly uniform adhesion across the first, second, and third glue-covered areas 102, 104, 106 may be achieved.
The expandable last 2 of
The expansion assembly 40 of the expandable last 2 of
In the exemplary embodiment of
The forefoot spring portion 56 has a waved shape. In particular, the forefoot spring portion 56 has a first exposed portion 56a and a second exposed portion 56b. The first exposed portion 56a is located at an instep portion of the expandable last 2. The second exposed portion 56b is located at a toe portion of the expandable last 2. The first and second exposed portion 56a, 56b may be thought of as high portions of the waved shape of the forefoot spring portion 56, when fitting a straight line through the waved shape of the forefoot spring portion 56.
The forefoot spring portion 56 further comprises a pressure exertion pad 56c. The pressure exertion pad 56c is arranged at the forefoot end portion of the forefoot spring portion 56.
The heel spring portion 57 extends from the lid 10 towards a heel portion of the expandable last 2. The heel spring portion 57 has a pressure exertion pad 57a at the heel end portion of the heel spring portion 57.
The forefoot spring portion 56 and the heel spring portion 57 are of a metal strip design. In the longitudinal direction of the expandable last 2, the forefoot spring portion 56 has the described waved shape from the lid 10 to the toe portion of the expandable last 2, and the heel spring portion 57 has the depicted curved shape from the lid 10 to the heel portion of the expandable last 2. In the transverse direction of the expandable last 2, i.e. in the direction orthogonal to the viewing plane of
In the exemplary embodiment of
An exception to the constant width of the forefoot spring portion 56 and the heel spring portion 57 are the pressure exertion pad 56c at the toe portion of the forefoot spring portion 56 and the pressure exertion pad 57a the heel portion of the heel spring portion 57. The pressure exertion pads 56c, 57a have a wider extension than the forefoot spring portion 56 and the heel spring portion 57, thus providing for a somewhat more extended application of pressure onto the expandable shell 6.
The spring action of the spring skeleton 55 is described as follows. Both the forefoot spring portion 56 and the heel spring portion 57 are configured to exert a spring force that pushes the forefoot spring portion 56 and the heel spring portion 57 upwards in the expandable last 2.
In this context, the term upwards corresponds to the upwards direction in the viewing plane of
With the spring skeleton 55 of the expandable last 2 of
It has been described that the spring skeleton 55 and the core support element 4 are jointly viewed as an expansion assembly. However, one can also view the spring skeleton 55 as an additional element that supplements the core support element 4. In particular, the core support element 4 may be embodied in any of the variations described above with respect to
The expandable last 2 of
The spring skeleton 55 of the expandable last 2 of
In the exemplary embodiment of
The instep spring element 58 is configured to exert localized pressure onto the instep portion of the expandable shell 6. For illustration, the instep spring element 58 is shown in two states/positions. On the one hand, the instep spring element 58 is shown in phantom, which may correspond to a positon/state directly after insertion of the expandable last 2 into the footwear. When in said positon/state, a spring action of the instep spring element 58 forces the instep spring element 58 upwards. This spring action leads to the instep spring element 58 being forced upwards and exerting localized pressure onto the instep portion of the expandable shell 6. Said pressure exertion position/state is shown in a solid line in
The expandable last 2 of
The expandable last 2 of
Within the expandable shell 6, a granulate chamber 61 is provided. A granulate port 62 is provided in the lid 10. The granulate port 62 forms a granulate channel into the granulate chamber 61. Via the granulate port 62, granulate 63 may be introduced into the expandable shell 6 and may be sucked out of the expandable shell 6. For illustrative purposes, a small amount of granulate 63 is shown within the granulate chamber 61 in
The granulate 63 that is introduced into the granulate chamber 61 may be provided by an external granulate source 64. The external granulate source 64 has a granulate container 65 and a granulate heater 67. The granulate container 65 is coupled to the granulate port 62 with a granulate dosing valve 66, being interposed between the granulate container 65 and the granulate port 62. Via the granulate heater 67 and the granulate dosing valve 66, the amount and temperature of the granulate 63 within the expandable shell 6 of the expandable last 2 may be controlled.
In operation, the granulate 63 may provide for a substantially uniform pressure onto the insert for pressing the same against the footwear. Also, with the granulate 63 being heated, the granulate 63 is an effective means for activating a heat-activated adhesive, which may be used for attaching the insert to the footwear. As described above, the expandable shell 6 may have, at least in one or more regions thereof, dimension-specific elastic properties. Also, as described above, a form-stable core support element or an expansion assembly may be arranged within the expandable shell 6. In this way, localized exertion of pressure may be combined with the more uniform exertion of pressure, as achieved via the granulate 63.
The expandable shell 6 of the expandable last 2 of
The waterproofness of footwear may be determined by use of the Centrifuge test described in U.S. Pat. No. 5,329,807, and incorporated by reference herein in its entirety. The centrifuge tests may be carried out for 30 minutes. The footwear article is considered to be waterproof if no leakage is seen after 30 minutes.
The breathability of footwear may be assessed in accordance with the determination of the Whole Boot Moisture Vapor Transmission Rate Test in accordance with the Department of Defense Army Combat Boot Temperate Weather Specifications. The specifications are as follows:
Whole Boot Breathability
The boot breathability test shall be designed to indicate the Moisture Vapor Transmission Rate (MVTR) through the test sample by means of a difference in concentration of moisture vapor between the interior and the exterior environment.
Apparatus
Procedure
MVTR=(Wi−Wf)/Td.
This test is in accordance with ASTM D8041 (2016).
For example, for a low ankle shoe of European shoe size 42, the footwear may be considered breathable if above calculated value is above 1.5 grams/hour. For larger/smaller shoe sizes, said limit value may be extrapolated in accordance with the increased/decreased surface area of the shoe.
The waterproofness and the breathability of the bootie as a whole may also be determined by use of the Centrifuge test and the Whole Boot Moisture Vapor Transmission Rate Test, respectively, as laid out above.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/065935 | 6/14/2021 | WO |