Exoskeleton finger protection system with predetermined breaking points

Abstract

Exoskeleton finger protection system consisting of at least two to three segments (tip, middle part, end piece) which are coupled to each other via mechanical connections, characterized in that targeted predetermined breaking points are provided at the connection points which give way under a defined load and thereby absorb the energy acting upon them.

Description

1. Problem statement

[0001] Certain sports, such as handball, football, and ice hockey, are known for being very intense and physically demanding. At the same time, these disciplines carry a high risk of injury, particularly to the hands. Goalkeepers, in particular, are at considerable risk of suffering finger and joint injuries due to external impacts.

[0002] Typically, two main types of injuries occur: • Overextensions, which are often reduced by so-called "finger taping" or rigid finger splints. • Fractures and capsule tears, which are caused in particular by strong frontal impacts, for example when a ball hits the fingertips at high speed.

[0003] Current technology shows that many sporting goods manufacturers are attempting to solve this problem with deformable foams or so-called finger-save inserts. While these systems do stiffen the finger, they do not reliably prevent the force of an impact from being transmitted to the finger joint. Therefore, injuries remain common despite the existence of protective systems.

[0004] From a physical point of view, there are basically two approaches to influencing the effect of a force in such a way that the underlying tissue remains protected: • Elastic deformation: The material absorbs the energy by bending or compressing. However, this method is difficult to implement in the finger area because the material is either too soft (insufficient protection) or too stiff (uncontrolled breaking). • Targeted breaking or destruction: In this process, a pre-weakened component absorbs the energy by giving way in a controlled manner, thus protecting the remaining structure – especially the finger.

[0005] This is precisely where the J-FractoGuard invention comes in: Through strategically integrated predetermined breaking points, the impact force is gradually reduced before it reaches the finger. This dissipates the energy transfer in several phases and minimizes the stress on the joint. 2 solution

[0006] The present invention relates to a three-part exoskeleton system designed for the targeted absorption of impact and bending loads in the finger area. The structure consists of three coordinated segments: the tip (1) (see Fig. 2), the middle part (2) (see Fig. 2) and the end piece (3) (see Fig. 2) The segments are coupled to each other via mechanical joint connections and serve to gradually reduce the forces acting on the finger. Structural principle - honeycomb pattern

[0007] Each segment features a honeycomb-shaped internal structure. This lightweight design allows for a combination of low weight and high structural strength. The underlying principle is based on the human bone structure, which achieves stability with a minimal amount of material through a combination of compact and cancellous tissue. Functional distance to the fingertip

[0008] Between the anterior exoskeleton tip (1) (see Fig. 2) A defined distance is provided between the exoskeleton and the actual fingertip. This space serves as a buffer zone to initially absorb the force generated in a frontal impact within the exoskeleton itself. Only this distance prevents the kinetic energy from being transferred directly to the soft tissue of the finger. Connection points with predetermined breaking points

[0009] The three main segments are connected via mechanical joints: • Connection between tip (1) (see Fig. 2) and middle part (2) (see Fig. 2) • Connection between middle part (2) (see Fig. 2) and end piece (3) (see Fig. 2) The connection principle is identical for both transitions: • At the top (1) (see Fig. 2) There is a forward-facing projection with a rounded end, which has a bore. • The adjacent segment (2 or 3) contains a box-shaped receptacle with the same internal dimensions, into which the pre-extension is inserted. • The connection is made via a bolt (4) (see Fig. 3), which is guided through the bore of the extension and anchored in the side walls of the receptacle. • The bolt (4) (see Fig. 3) is dimensioned slightly smaller than the bore to allow limited movement. • There are controlled breaking points on each side of the bolt (5) (see Fig. 3), which give way under high force and thus absorb energy gradually. • After the predetermined breaking point fails, the pre-extension slides in a controlled manner into the box-shaped collection container (6) (see Fig. 3) a, thereby transferring the remaining residual energy to the following segment. Overstretch protection

[0010] To prevent overextension of the finger backwards, a [feature] is provided on the back of the box-shaped collection container (6) (see Fig. 3) a stabilizing intention (7) (see Fig. 2) attached. This acts as a mechanical stop splint, preventing backward movement beyond the physiological range. This provides additional stabilization to the finger while maintaining its natural mobility. 3 How it works

[0011] The J-FractoGuard exoskeleton system works by preventing external impact or hyperextension forces from acting directly on the finger joints and capsules, instead absorbing them first through the system's upstream segments. Specifically incorporated predetermined breaking points (5) (see Fig. 3) on the bolts (4) (see Fig. 3) the task of enabling a defined and controlled energy intake in the event of an overload.

[0012] Under stress, these predetermined breaking points (5) (see Fig. 3) to a controlled material failure or deformation, so that the applied energy is gradually absorbed and kept away from the sensitive joint areas. The system is designed so that a fracture always occurs at the intended weak points before any serious stress or injury to the finger can occur.

[0013] An additional safeguard against backward movement is provided by the extension (7) (see Fig. 2) above the predetermined breaking points. This acts as a mechanical lock and prevents the finger from being hyperextended backwards. This not only dissipates the impact energy in a controlled manner but also effectively prevents hyperextension of the fingers. The principle corresponds to the mechanical function of the exoskeleton's joints themselves, which also feature a defined material failure or controlled deformation.

[0014] The segments (1-3) (see Fig. 2) integrated honeycomb structure (8) (see Fig. 1) Ensures an optimal balance between weight and strength. Similar to the structure of human bones, cavities and rib structures provide high stability with minimal material usage. Furthermore, the open structure allows for better air circulation within the glove, improving comfort during sports activities.

[0015] In summary, the system offers three key protection mechanisms: 1. Energy absorption through targeted weak points (5) (see Fig. 3) under high loads. 2. Mechanical barrier against overextension by the stabilizing extension (7) (see Fig. 2). 3. Structural strength at low weight due to the honeycomb-like internal structure (8) (see Fig. 1).

[0016] The combination of these three principles ensures holistic protection of the finger, effectively controlling and distributing both frontal impact forces and backward movements. 4 advantages

[0017] The J-FractoGuard exoskeleton system presented here offers several key advantages over existing finger protection technologies. The combination of targeted energy redirection, mechanical stabilization, and lightweight construction results in significantly improved injury protection, especially under sport-specific stresses. 1. Targeted energy absorption through predetermined breaking points (5) (see Figure 3)

[0018] In contrast to classic finger-save systems, which merely offer rigid support, the present invention utilizes defined predetermined breaking points (5) (see Fig. 3), which yield in a controlled manner under a specific load. Through the controlled fracture process, the kinetic energy is partially absorbed and transferred via the segments (1-3) (see Fig. 1) distributed before it can act on the joint or capsule. This significantly reduces the risk of fractures and capsule tears. 2. Protection against hyperextension (overstretching of the finger joints)

[0019] A slightly forward-positioned housing element with a stabilizing extension (7) (see Fig. 2) It prevents hyperextension of the finger. In this way, both frontal injuries and typical hyperextension injuries are effectively avoided. 3. Biomechanically inspired lightweight design principle

[0020] The honeycomb-like internal structure (8) (see Fig. 1) The segmented design allows for an optimal weight-to-stability ratio. This construction reduces the system's mass without compromising protective performance, while simultaneously improving air circulation within the glove. The result is increased stability combined with high wearing comfort. 4. Modular design and adaptability

[0021] The exoskeleton consists of three main segments (1-3) (see Fig. 1), which via bolts (4) (see Fig. 3) are interconnected. This modular design allows for easy replacement of individual elements and individual adaptation to different finger sizes and shapes. This makes the system suitable for both professional and recreational sports. 5. Multisport applicability

[0022] Although the system was primarily developed for use in goalkeeper gloves, it can also be used in other sports such as handball, volleyball, or ice hockey. Wherever finger injuries occur due to impact or overstretching forces, the system offers effective protection. 6. Reduction of tape and splint requirements

[0023] Many athletes currently use tape bandages or simple splints to stabilize their fingers. The exoskeleton presented here can partially replace these aids while ensuring a consistently high level of protection. This saves material and time, and enables a reusable, environmentally friendly solution. 5 Prototype and next steps

[0024] A first functional prototype of the J-FractoGuard exoskeleton system was manufactured using additive manufacturing (3D printing). The three-part segment design with predetermined breaking points (5) (see Fig. 3) and box-shaped receptacle (6) (see Fig.3) Implemented. Tests conducted so far confirm that the design allows the planned flexibility while simultaneously ensuring effective protection against overextension. Furthermore, the intended energy absorption at the predetermined breaking points has been experimentally verified. However, the currently used material (PLA) still offers potential for optimization with regard to elasticity and fracture toughness. Planned further development

[0025] The following steps are planned for the further development of the system: 1. Material optimization: The selection of alternative materials such as TPU or PETG aims to achieve higher elasticity, better energy absorption, and improved fatigue strength. This should ensure the system remains both robust and durable. 2. Fastening system: Development of an ergonomic fixation, for example using Velcro, elastic silicone cuffs or textile embedding, to prevent slipping on the finger and increase wearing comfort. 3. Stress and practical tests: Conducting targeted load tests under realistic impact scenarios (e.g., football and handball tests) for quantitative analysis of energy absorption and validation of fracture characteristics. 4. Integration into glove prototype: Installation of the exoskeleton system in a goalkeeper glove for practical testing in a sporting environment and to investigate the interaction between material behavior and finger mobility. 5. Geometric optimization: Reduction of the overall width of the prototype to allow for a better fit and integration under a standard glove. 6. Improvement of haptic feedback: Applying a thin layer of foam or silicone to the inside of the fingertip to maintain the natural feel of the finger and improve sensory perception during ball contact.

[0026] The combination of these steps serves to further develop the prototype from a functional test unit into a practical, marketable product. In parallel, the design will be optimized with regard to manufacturing effort, lifespan, and user-friendliness.

Claims

[1] Exoskeleton finger protection system consisting of at least two to three segments (tip, middle part, end piece) which are coupled to each other via mechanical connections, characterized by that targeted weak points are provided at the connection points, which give way under a defined load and thereby absorb the energy acting upon them. [2] Exoskeleton finger protection system according to claim 1, characterized by that the connections are made by bolts in corresponding bores, the bolts being provided with predetermined breaking points. [3] Exoskeleton finger protection system according to any of the preceding claims, characterized by , that a stop is provided above the predetermined breaking points, which prevents the finger from being overextended backwards. [4] Exoskeleton finger protection system according to any of the preceding claims, characterized bythat the segments have a honeycomb-like or similar structure that ensures an optimal weight-to-stability ratio. [5] Exoskeleton finger protection system according to any of the preceding claims, characterized by , that behind the connecting piece of a segment a housing is arranged as a collection container, which transfers the residual force generated during the breakage in a controlled manner to the next segment. [6] Exoskeleton finger protection system according to any of the preceding claims, characterized by , that a functional distance is provided between the fingertip and the exoskeleton tip, so that in the event of a frontal impact, the energy is absorbed by the predetermined breaking points before the remaining force is transferred directly to the finger. [7] Exoskeleton finger protection system according to any of the preceding claims, characterized bythat the system is designed as a standalone module and can be integrated into sports gloves or worn separately. [8] Use of the exoskeleton finger protection system according to one of the preceding claims in the field of sports with an increased risk of finger injuries, in particular football, handball, volleyball or ice hockey, or for general protection against the aforementioned types of injuries.

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