Device and method for measuring the interior of a shoe

Abstract

The present invention relates to a device for measuring the interior of a shoe, wherein the device comprises a sensor head and a feed unit, wherein the sensor head comprises a laser distance meter, and a method for measuring the interior of a shoe. Advantageously, the measurement of the shoe's interior can be carried out independently of the material of the shoe's upper.

Description

[0001] The present invention relates to a device and a method for measuring the interior of a shoe.

[0002] Shoes consist of various components that are carefully assembled to ensure comfort, durability, and functionality. The upper (or shaft) is the part of the shoe that encloses the foot and is usually made of leather, textile, or synthetic materials. The insole provides cushioning and support, while the midsole offers additional padding and stability. The outsole is the bottom part of the shoe that makes direct contact with the ground and is made of durable materials such as rubber or polyurethane. Other important components include the heel, which provides additional support, and the toe cap, which protects the toes. Additionally, various technical components such as cushioning systems or special closure systems can be integrated to further enhance comfort and functionality.

[0003] The shoe interior is the area inside a shoe that receives and encloses the foot. This space includes all the inner surfaces of the upper, the insole, and any padding or lining. The shoe interior is designed to support the shape and contours of the foot, adhering to specific dimensions and specifications to ensure comfort, fit, and stability.

[0004] Shoes are typically manufactured using lasts, which determine a specific shoe size and fit. After the last is removed, the shoe usually deforms and shrinks. Assumptions about this shrinkage process allow for the creation of a last that, after the shoe is removed and shrinkage has occurred, approximates the desired shoe size. Nevertheless, discrepancies between the intended shoe size and fit and the actual shoe size and fit are common in industrial shoe manufacturing.

[0005] Nowadays, manufactured shoes are often measured as part of the quality control process during production. This serves to determine the exact size and fit before the shoe is sold and to mark it accordingly. In this way, the customer can choose a shoe that corresponds to their foot size and shape.

[0006] The shape of the human foot varies considerably from person to person and is crucial for the fit and comfort of shoes. Feet can have different lengths, widths, and arches, which means that standardized shoe sizes often don't fit all wearers optimally. This variability in foot shape presents a challenge for shoe manufacturing, especially when it comes to developing shoes that are both functional and comfortable. Innovative techniques for precisely measuring and adapting to individual foot shapes are therefore of great importance to ensure a better fit and increased wearing comfort. Such methods can not only increase customer satisfaction but also improve efficiency and accuracy in shoe production.

[0007] Determining the correct fit and shoe size is therefore a crucial task that requires technical assistance. Especially for measuring shoe collections distributed through the shoe trade, methods are needed that allow for the precise measurement of shoe series quickly and with minimal personnel.

[0008] Manual methods exist in which templates with measuring units are inserted into the shoe. Current techniques also include measuring instruments with telescopically extendable rulers that are inserted into the shoe to measure length. Mechanical instruments for measuring circumference are also used. These are inserted into the shoe's interior and manually adjusted to the shoe's interior boundaries using knurled screws and knurled sections. However, these methods are time-consuming, often lead to inaccurate results, or are unsuitable for certain shoe shapes. In particular, manual methods are prone to operator error, which can distort the result.

[0009] In addition to mechanical measuring systems, radiological methods are also available today. These primarily use X-rays to scan the shoe and capture an image radiographically. The subsequent measurement is performed either manually or automatically through image analysis (see WO 2005 / 111 539 A1). A distinction can be made between two- and three-dimensional imaging techniques. Two-dimensional methods represent the shoe as a projection image, while three-dimensional methods generally generate a series of spatial layered images, usually based on computed tomography (CT). For example, DE 10 2012 004 064 B4 describes a method and a device for the non-destructive determination of the internal dimensions of shoes using a computed tomography system.

[0010] A disadvantage of measuring the inside of a shoe using X-rays is that the necessary equipment is relatively complex and expensive, and requires appropriate shielding. Furthermore, measuring shoes made of certain materials, such as metals, is not possible. For example, work shoes often have metal toe caps.

[0011] The present invention therefore aims to provide an optimized and cost-effective device for measuring the interior of a shoe. A further objective of the invention is to provide an optimized method for measuring the interior of a shoe.

[0012] The problem is solved with a device for measuring the inside of a shoe by the device having a sensor head and a feed unit, wherein the sensor head has a laser distance meter, and the feed unit has means for measuring the feed rate.

[0013] KR 10 2018 0 055 636 A relates to a device for measuring the interior of a shoe and a method for providing a corresponding service, and in particular a measuring device for measuring the interior of the shoe using a fastening element and a sensor, as well as an external electronic device for generating three-dimensional information about the interior of the shoe using this measuring device.

[0014] US 2016 / 0286906A1 describes a method for acquiring size and shape data of an object, comprising: positioning an essentially two-dimensional reference object on a plane near the object; providing a digital camera comprising a screen, a digital image sensor, a processor, memory, and a transmitter; displaying the reference object and the object together on the screen along with a frame corresponding to a projection of the reference object from a desired angle; and tilting the screen along with a frame corresponding to an outline of the reference object to align the outline with the edge of the reference object on the screen.

[0015] DE 10 2004 045 858 A1 discloses a device for measuring the interior of a shoe, comprising a shaft part and a foot part adjoining the shaft part, wherein the foot part can be adapted to the length of the interior of the shoe via the shaft part in accordance with a teaching, wherein the foot part is dimensioned and constructed in such a way that it can be adjusted from a short insertion state suitable for shoes of any size to a measuring state approximately adapted to the length of the interior.

[0016] To measure the inside of the shoe, the sensor head is inserted into the shoe at the heel. The shoe can be fixed in place during the measurement. This can be achieved, for example, by protrusions on a plate. Clamps or springs can also be used to secure the shoe.

[0017] The feed unit, which could be a linear motor, for example, moves the sensor head through the inside of the shoe. The feed occurs along the insole and can be continuous or incremental. The feed unit can move the sensor head from the heel area to the toe cap or foresole area. The movement can also be reversed. For example, moving the sensor head from the toe cap to the heel can allow for verification of the previous measurement or for taking another measurement.

[0018] The laser distance meter measures the distance between the sensor head and the upper material of the shoe. The sensor head can have one or more laser distance meters. A measurement can be taken by the laser distance meter after each feed by the feed unit or at specific time intervals during continuous movement by the feed unit. The feed occurs in specific steps or at a specific speed. The laser distance measurement data can be stored as a 3D point cloud.

[0019] Using a control unit, a 3D image of the shoe's interior can be created from the 3D point cloud. A 3D image of one or both feet can be generated for the customer. This can be done, for example, using manual measurement, photogrammetry, laser scanning (LiDAR), or structured light scanning. The 3D image of the foot provides information about the customer's foot shape. It is advantageous to compare the 3D image of the shoe's interior with the 3D image of the customer's foot without having to try on the shoe beforehand. Furthermore, this comparison can determine the shoe's comfort level, for example, whether pressure points might occur, and / or which shoe size is needed. Particularly beneficial is the ability to pre-select shoe models and / or sizes based on the 3D image of the shoe's interior and the 3D image of the foot. This is especially advantageous for online shoe retailers.The comparison of the 3D image of the shoe's interior and the 3D image of the foot can be achieved, for example, using machine learning. The customer's previous shoes can be used as data for this purpose. Similarly, data on comfort from previous shoe fittings can be used.

[0020] The device offers the advantage of quick and cost-effective measurement of the shoe's interior. Typically, only one shoe model of one size needs to be measured, allowing for rapid processing of large inventories. Personalized customer consultations based on foot shape are particularly beneficial, saving time during shoe fittings. Compared to conventional radiological devices, this one is significantly more cost-effective to manufacture and can be operated safely and reliably on-site in a shoe store. Furthermore, the laser distance meter is independent of the upper material; for example, even shoes with steel toe caps can be measured.

[0021] The feed unit can include means for measuring the feed rate. In the case of incremental feed, the means for measuring the feed rate can include displacement sensors, such as inductive displacement sensors, capacitive displacement sensors, laser sensors, linear potentiometers, Hall effect sensors, or optical sensors. In the case of feed at a specific speed, the means for measuring the feed rate can include velocity sensors, such as Hall effect sensors, optical speedometers, tachometers, or magnetoresistive sensors. Advantageously, the 3D point cloud data can be enhanced with precise longitudinal displacement data.

[0022] One embodiment of the invention consists in the device having means for impact detection.

[0023] The means for impact detection can include, for example, a pressure switch or a laser distance meter. These means are directed forward towards the foresole or toecap and / or towards the heel or sole. Advantageously, the impact detection means can determine when a complete measurement along the sole is finished. Thus, the impact occurs at the toecap as the sensor head moves from the heel to the toecap. The measurement is complete after the impact occurs at the toecap.

[0024] Another embodiment of the invention consists in the fact that the laser distance meter is rotatable.

[0025] The sensor head can incorporate a single laser distance meter. This laser distance meter can be rotated around its longitudinal axis (the feed direction). Specifically, the rotation can be 180°. This allows for the advantageous measurement of the entire upper material. Measurements can be taken after each feed step or at specific time intervals. Rotation perpendicular to the longitudinal axis is also possible. For example, the distance to the heel and / or the toe cap can be measured. This can result in cost savings.

[0026] Another embodiment of the invention consists in the sensor head and the feed unit being connected to each other by means of an elastic element.

[0027] The elastic element can be, for example, an elastic rod. The sensor head and the feed unit can be connected via an elastic element. The feed unit can be located outside the shoe. The sensor head can be attached to one end of the elastic element. The sensor head can be inserted into the shoe from above. Inside the shoe, the elastic element can be bent so that the longitudinal axis of the sensor head points towards the toe cap. As it moves through the feed unit, the elastic element deforms, causing the sensor head to move along the insole towards the toe cap. During this movement, the feed unit pushes the elastic element downwards towards the sole of the shoe. The feed can be incremental or continuous. The sensor head is pressed against the insole and does not lift from it.The measurement result is advantageously not distorted by lifting. The elastic element is particularly beneficial because it adapts to all possible shoe shapes. The feed unit itself does not need to be inserted into the shoe; only the sensor head needs to be guided into the shoe's interior. This allows for simple automation of the measurement process. After the measurement, the sensor head can simply be guided out of the shoe's interior using the elastic element.

[0028] It is advantageous for the elastic element to be a spring steel rod.

[0029] The spring steel allows for repeated elastic deformation and can press the sensor head onto the shoe's insole.

[0030] An advantageous embodiment consists in the elastic element being connected to the sensor head by means of a joint.

[0031] The joint can be positioned at the connection between the sensor head and the elastic element. Advantageously, the joint ensures that the sensor head remains flat against the insole at all times during measurement. This reduces the risk of measurement errors and makes it easier to insert the sensor head into the shoe. The joint can also incorporate a spring or motor. For example, the joint can apply torque to the sensor head to prevent it from lifting off the insole during insertion.

[0032] Another embodiment of the invention consists in the sensor head having a position sensor.

[0033] The orientation sensor can be, for example, a gyroscope, an accelerometer, a magnetometer, an inclinometer, or an optical position sensor. The orientation sensor determines whether the sensor head is resting on the insole or has lifted off it. The measurement is most effective when the sensor head is in the desired position and / or orientation on the shoe's insole. Correction calculations for the sensor head's spatial orientation can also be performed.

[0034] Finally, a method for measuring the interior of a shoe belongs to the invention, wherein the sensor head is moved stepwise or continuously by the feed unit, wherein after each step or after a certain time interval the laser distance meter records measured values, after recording the measured values ​​the sensor head is moved by the feed unit by one step or is moved further at a continuous speed.

[0035] The measurement can be taken from the heel towards the toe cap or vice versa. Advantageously, the measurement results can be compared or averaged in both directions to identify measurement errors or correct readings. At each step or time interval, the distance to the upper material of the laser distance meter is measured. In the case of a single rotating laser distance meter, the sensor head is moved incrementally and the laser distance meter is rotated 180°, with measurements taken in discrete degree increments. The frequency of the measurements can be adjusted to suit the requirements. The increment or speed of the movement and the time intervals of the measurements can also be adjusted to suit the requirements.After the measurement, a 3D point cloud of measured values ​​can be generated in a control unit using the data from the laser distance meter and the selected parameters for the feed rate or feed speed, the measurement time intervals, and, in the case of a rotatable laser distance meter, the degree increments. A 3D model of the shoe's interior can then be created from this 3D point cloud. This model can be compared to a 3D model of a foot, allowing conclusions to be drawn about the shoe's comfort.

[0036] Exemplary embodiments of the invention are described in more detail below with reference to drawings.

[0037] It shows Fig. 1 a sectional view of a device according to the invention.

[0038] In Fig. Figure 1 shows a device 1 according to the invention for measuring the interior of a shoe 2. The shoe 2 is fixed by an insert 3. The device 1 has a sensor head 4 and a feed unit (not shown), which can be, for example, a linear motor. The sensor head 4 and the feed unit are connected to each other by an elastic element 5. The sensor head 4 has power and data cables 6. The sensor head 4 and the elastic element 5 are connected to each other via a joint 7. This ensures that the sensor head rests on the sole 8 when being fed through the interior of the shoe. The sensor head 4 has a position sensor 9. The position sensor 9 enables verification of whether the sensor head 4 rests on the sole 8. The sensor head 4 has a rotatable laser distance meter 10. The laser distance meter 10 can be rotated in degree increments around the longitudinal axis of the device.The sensor head 4 is rotated around the feed direction and the distance to the upper material 12 is determined using laser 11. The sensor head 4 has means for impact detection 13. The impact detection means 13 allow it to be determined whether the sensor head has reached the toe cap 14 and the measurement is complete. The sensor head 4 is fed from the heel 15 to the toe cap 14.

[0039] Fig. Figure 2 shows a schematic representation of a 3D image of the inside of a shoe, created using data from the laser distance measurement of the device according to the invention. The laser distance measurement data can be in the form of a 3D point cloud. The 3D image can be generated, for example, by connecting the points of the 3D point cloud.

Claims

[1] Device (1) for measuring the interior of a shoe, characterized by , that the device (1) has a sensor head (4) and a feed unit, wherein the sensor head (4) has a laser distance meter (10), and the feed unit has means for measuring the feed. [2] Device according to claim 1, characterized by , that the device (1) has means for impact detection (13). [3] Device according to claim 1 or 2, characterized by , that the laser distance meter (10) is rotatable. [4] Device (1) according to any one of the preceding claims, characterized by , that the sensor head (4) and the feed unit are connected to each other by means of an elastic element (5). [5] Device (1) according to claim 4, characterized by , that the elastic element (5) is a spring steel rod. [6] Device (1) according to one of claims 4 or 5, characterized by, that the elastic element (5) is connected to the sensor head (4) by means of a joint (7). [7] Device (1) according to any one of the preceding claims, characterized by , that the sensor head (4) has a position sensor (9). [8] Method for measuring the interior of a shoe using a device according to one of the preceding claims, characterized by that the sensor head (4) is moved stepwise or continuously by the feed unit, wherein after each step or after a certain time interval the laser distance meter (10) records measured values, after or during the recording of the measured values ​​the sensor head (4) is moved by the feed unit by one step or is moved further at a continuous speed.

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