Sandbag

Abstract

The present application discloses a sandbag (1) consisting of a multi-material and multi-layer structure that provides a combination of materials that allows for consistency similar to the human body, resulting in a very realistic training experience. The invention relates to a sandbag comprising a body having an outer synthetic leather surface (1.1), the body being formed of a two-layer foam structure (1.2, 1.3) and a core portion, each layer of foam having a different density, the core portion being composed of a bladder structure (1.4) comprising at least one bladder, the bladder being a container for liquid storage.

Description

TECHNICAL FIELD

[0001] The present application relates to sandbags, and more particularly, to a sandbag having a multi-layer and multi-material construction. BACKGROUND

[0002] Sandbags were originally used by boxers or martial arts practitioners to improve overall punching technique. In recent years, non-professional practitioners have also begun to use sandbags, hoping to obtain the benefits of power enhancement and aerobic exercise through punching movements. In addition, sandbags are now used by many as a source of stress relief, as martial arts training programs have proven to be an effective way to improve health and fitness. Many people see the positive effects of martial arts training, such as improved cardiovascular endurance, increased muscle strength and firmness, and weight loss. It also helps users to gain a sense of inner strength and emotional balance.

[0003] Conventional sandbags come in a variety of sizes and shapes, typically spherical, pear-shaped, or elongated cylindrical structures, with an outer layer made of leather or synthetic composite material, and an inner filling of fillers such as airbags or other fill materials, such as cotton or other synthetic fiber materials.

[0004] Generally, sandbags used for both punching and kicking training are elongated cylindrical as described above, which have a larger surface area and a weight of up to 30 kilograms or more, with a density of more than 10 pounds per cubic foot, thus having a relatively high hardness. One of the main reasons for the ordinary sandbag to have such weight and hardness is that it can provide an ideal resistance when the user kicks or punches the sandbag, and can simulate the human contact feeling in competitive combat training. The weight of the sandbag also affects the training effect: if the sandbag is too heavy, it is difficult to push; if the sandbag is too light, the training effect is not good.

[0005] To enhance the overall training experience, the design of the sandbag is set to a specific weight, and filled with memory materials or compressible materials, which can also reduce or adjust the impact resistance to some extent, thereby avoiding or at least reducing sports injuries.

[0006] However, such sandbags have a problem: due to their internal structural design, it is difficult to maintain consistency in shape and resistance during use, especially after long-term use, specifically, it is difficult to maintain the stability or displacement consistency of the sandbag filler. In fact, when a large part of the outer surface of the training sandbag is subjected to repeated strong impact for a long time, the internal filler may be displaced and deviate from the original roughly uniform distribution state, resulting in uneven resistance in the surface contact area of the sandbag (whether for punching or kicking).

[0007] Further, considering that sandbags are usually hung on support members, gravity also helps the filling material to gradually migrate and move from the top to the lower part of the bag, especially when repeatedly punched and kicked, which results in uneven distribution of the filling material and is accompanied by uneven and inconsistent contact resistance, making the exercise or practice process not as desired.

[0008] The present application aims to solve the above-mentioned problems through an innovative design. SUMMARY

[0009] The present application aims to mitigate the above-mentioned drawbacks of the prior art devices, therefore providing a sandbag capable of maintaining its resistance and elasticity consistency throughout the heavy and harsh use.

[0010] Therefore, the object of the present application is to provide a sandbag composed of a multi-material, multi-layer structure. Therefore, this sandbag provides a combination of materials that allows to achieve a consistency similar to that of the human body, thus generating a very realistic training experience. Furthermore, in order to reach the necessary weight of the bag, the main body of the bag comprises a bladder structure with at least one bladder to be filled with liquid.

[0011] In a preferred design, the bladder structure comprises an array of four 20-liter water bladders. By dividing the bladder into 20-liter portions, it is very easy for the user to fill each bladder individually, for example, by lifting each bladder using the ergonomic handle on top of the bladder and placing it into the bag, greatly improving the ease of use. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 A full cross-sectional view of one embodiment of a sandbag, object of the present application, is shown, in which the reference numbers indicate: 1 - sandbag; 1.1 - synthetic leather outer surface; 1.2 - first foam layer; 1.3 - second foam layer; 1.4 - bladder structure.

[0014] Figure 2 A longitudinal cross-sectional view of one embodiment of a sandbag (1), object of the present application, is shown, in which the reference numbers indicate: 1.1 - synthetic leather outer surface; 1.2 - first foam layer; 1.3 - second foam layer; 1.4 - bladder structure; 1.5 - bladder.

[0015] Figure 3 A schematic view of one embodiment of a bladder forming the core part of the bladder structure of the sandbag is shown. The reference numbers indicate: 1.5 - pocket; 1.6 - valve group.

[0016] Figure 4 a schematic view of one embodiment of a sandbag attached to two surfaces perpendicular to each other is shown, in which the reference numbers indicate: 1 - sandbag; 2 - anchoring module; 3 - first support surface; 4 - second support surface. DETAILED DESCRIPTION

[0018] The most general and preferred design solutions of the present application have been set out in the abstract. These design solutions will be described in detail below in connection with other preferred embodiments of the present application.

[0019] In one preferred embodiment of the sandbag (1) of the present application, the sandbag (1) comprises a body having a synthetic leather outer surface (1.1) and formed by at least two inner layers of foam. A first foam layer (1.2) is formed adjacent to the synthetic leather surface (1.1) and a second foam layer (1.3) is formed adjacent to the first foam layer (1.2) and towards the inside of the body of the bag; the first and second foam layers (1.2, 1.3) have different densities.

[0020] The core portion is constituted by a pocket structure (1.4) comprising at least one pocket, suitable for containing at least a liquid reservoir.

[0021] The sandbag (1) according to this preferred embodiment is formed by a combination of materials that allows to achieve a consistency similar to that of the human body, thus creating a very realistic training experience. Furthermore, the double foam layer structure (1.2, 1.3) has a tubular shape arranged along the entire surface of the sandbag (1) and not locally in specific portions of the body of the bag, thus forming a uniform layer capable of maintaining its arrangement, thus providing a uniform resistance on the surface contact area of the bag.

[0022] In another embodiment, which can be combined with the preferred embodiment, the outer surface (1.1) of the sandbag (1) is a synthetic leather surface. This material is both environmentally friendly and very durable. More specifically, the synthetic leather surface (1.1) can be made of a combination of a natural fiber matrix and at least 50% recycled PU polymer.

[0023] In another embodiment, which can be combined with any of the preceding embodiments, the first foam layer (1.2) is a medium-density foam. More specifically, said first foam layer (1.2) can have a thickness of 50 to 70 millimeters.

[0024] In another embodiment, combinable with any of the preceding ones, the second foam layer (1.3) comprises a high-density expanded polyethylene (EPE) foam. Said second foam layer (1.3) can have a thickness comprised between 30 and 50 mm.

[0025] The proposed multi-layer arrangement of two types of foam having different densities and thicknesses allows to protect the bladder structure (1.4), In another embodiment, combinable with any of the preceding ones, at least one bladder (1.5) of the bladder structure (1.4) is a container for liquid storage, for example water. By having a core similar to water, the sandbag (1) acquires a texture and resistance similar to the human body. Moreover, a core similar to water has the advantage of making the deformation of the bag and the reaction to the impact of the user more realistic.

[0026] In another embodiment, combinable with any of the preceding ones, the bladder (1.5) is a membrane made of PVC polymer and comprises at least one valve group (1.6) mounted at one end of the container and connected to the inside of said container. The valve group (1.6) can comprise an inlet and a heat-sealed portion to achieve a liquid-tight seal. To be able to fill or empty, each bladder (1.5) can have a flat 65 mm valve. The valve (1.6) can also be collapsible and able to perform a dual function: bidirectional water filling and unidirectional low-end pressurization.

[0027] In another embodiment, combinable with any of the preceding ones, each bladder (1.5) has a volume of 20 liters. By dividing the bladder (1.5) into 20 liter portions, it makes it very easy for the user to fill each bladder (1.5) individually, to lift each bladder and put it into the sandbag (1) individually using an ergonomic handle that can be mounted on top of the bladder (1.5), greatly improving the ease of use.

[0028] In another embodiment, combinable with any of the preceding ones, the main body of the sandbag (1) has an elongated shape and the bladder structure (1.4) of the core portion comprises an array of at least two bladders (1.5) arranged longitudinally along one longitudinal axis. To this end, the bladders (1.5) of the array have a shape suitable to be stacked on top of each other. More specifically, each bladder (1.5) has a cylindrical shape consisting of a top and a bottom parallel circular base joined by a curved surface, wherein the top circular base of a first bladder is suitable to receive the bottom circular base of a second bladder, and so on, so as to form a vertical stack of bladders (1.5). By making the bladders (1.5) cylindrical in shape, it is possible to vertically stack the desired number of bladders (1.5), thus guaranteeing the proper balance and therefore the stability of the sandbag (1). To this end, each bladder (1.5) can also comprise a connector, for example a connecting ring, to achieve a better connection with the adjacent bladders.

[0029] In another embodiment, combinable with any of the preceding ones, the bladder structure (1.4) comprises an array of four bladders (1.5).

[0030] In another embodiment, combinable with any of the preceding ones, the sandbag (1) further comprises at least one sensing module for determining the impact force of the user's hits. The at least one sensing module consists of at least one set of accelerometers embedded in the first foam layer (1.2). The specific positioning of the sensors in the first foam layer (1.2) guarantees, on the one hand, the correct positioning inside the multilayer structure of the sandbag (1) to measure the impact force and, on the other hand, the full mechanical protection of the sensors from the impact.

[0031] In another embodiment, combinable with any of the preceding ones, the sandbag (1) further comprises an anchoring module (2). The anchoring module (2) comprises anchoring means adapted to anchor the body of the bag to a first surface (3). More specifically, in another embodiment, the anchoring module (2) further comprises anchoring means adapted to anchor the sandbag (1) to a second surface (4), wherein the first surface (3) and the second surface (4) are perpendicular to each other. The use of these two anchoring points, and thanks to the multilayer structure of the sandbag, allows a more realistic reproduction of the deformation of the sandbag and of the reaction to the user's hits, thus improving the training experience of the user.

[0032] Exemplary embodiments

[0033] The sandbag (1) comprises a body made of light grey synthetic leather, with two different foam layers (1.2, 1.3) and, at the core, an array of four water bladders (1.5). This combination of materials allows to achieve a consistency similar to the human body and to create a very realistic training experience. The eco-friendly material chosen for the outer part of the bag is both eco-friendly and very resistant, it is a combination of a natural fiber matrix that provides strength and support to the recycled PU polymer, which gives the outer part of the bag texture, with more than 50% of recycled PU polymer.

[0034] There are two types of foam that make up the interior of the body of the sandbag: the first foam layer (1.2), immediately adjacent to the outer skin (1.1), is of medium density, with a thickness of 50 to 70 mm; the second layer, adjacent to the first, is a hard foam made of expanded polyethylene (EPE). Between the foam layers (1.2, 1.3) there are three accelerometers that determine the impact force of each hit by the user.

[0035] To achieve the necessary weight of approximately 90 kg of the body of the bag, enabling it to absorb the impact of even the strongest users, the bladder structure (1.4) comprises an array of four 20-litre water bladders (1.5). By dividing the bladders (1.5) of the bladder structure (1.4) into 20-litre portions, the user can easily fill each bladder (1.5) individually, using the ergonomic top handle of the bladder (1.5) to lift each bladder and place it into the sandbag (1). Each water bladder (1.5) has a cylindrical shape and is made of at least 0.8 mm thick PVC polymer and is heat-sealed to achieve a water-tight seal. To be able to fill or empty, each bladder (1.5) has a flat 65 mm valve.

Claims

1. A sandbag (1), comprising: - A body having a leather outer surface (1.1); the body is formed of the following parts: - At least two foam inner layers; a first foam layer (1.2) formed adjacent to the leather surface (1.1) and a second foam layer (1.3) formed adjacent to the first foam layer (1.1) and toward the interior of the body; the first and second foam layers (1.2, 1.3) have different densities; - A core portion consisting of a sac structure (1.5) including at least one sac (1.6); the sac (1.6) is a container for liquid storage.

2. The sandbag (1) according to claim 1, wherein the outer surface (1.1) is a synthetic leather surface.

3. The sandbag (1) according to claim 2, wherein the artificial leather surface is made of a combination of a natural fiber matrix and at least 50% recycled PU polymer.

4. The sandbag (1) according to any one of the preceding claims, wherein the first foam layer (1.2) is medium-density foam.

5. The sandbag (1) according to claim 4, wherein the thickness of the first foam layer (1.2) is 50 to 70 mm.

6. The sandbag (1) according to any one of the preceding claims, wherein the second foam layer (1.3) comprises high-density expanded polyethylene (EPE) foam.

7. The sandbag (1) according to any one of the preceding claims, wherein at least one bladder (1.5) of the bladder structure (1.4) is a container for liquid storage.

8. The sandbag (1) according to claim 7, wherein the liquid is water.

9. The sandbag (1) according to claim 7 or claim 8, wherein the bladder (1.5) is a membrane made of PVC polymer and includes at least one valve assembly (1.6) mounted on one end of the container, the valve assembly being connected to the interior of the container; the valve assembly (1.6) includes an inlet and a heat-sealed portion.

10. The sandbag (1) according to any one of claims 7 to 9, wherein the volume of the bag (1.5) is 20 liters.

11. The sandbag (1) according to any one of the preceding claims, wherein the body of the bag has an elongated shape, and the bladder structure (1.4) of the core portion comprises an array of at least two bladders (1.5) arranged longitudinally along a longitudinal axis; the bladders (1.5) of the array having a shape suitable for stacking on top of each other.

12. The sandbag (1) according to claim 11, wherein the bladder (1.5) has a cylindrical shape consisting of a top and bottom parallel rounded bottom joined by curved surfaces; wherein the top rounded bottom of the first bladder is adapted to receive the bottom rounded bottom of the second bladder.

13. The sandbag (1) according to claim 11 or claim 12, wherein the bladder structure (1.4) comprises an array of four bladders (1.5); preferably each bladder has an ergonomic handle and a connector; preferably the connector is a connecting ring.

14. The sandbag (1) according to any one of the preceding claims further includes at least one sensing module; the at least one sensing module is installed between the foam layers (1.2, 1.3).

15. The sandbag (1) according to any one of the preceding claims further includes an anchoring module (2); the anchoring module includes an anchoring device adapted to anchor the body of the bag to a first surface (3); optionally, the anchoring module (2) further includes an anchoring device adapted to anchor the bag to a second surface (4); the first and second surfaces (3, 4) are perpendicular to each other.

Images