WO2024105165A1

WO2024105165A1 - Self-inflating ball for play

Info

Publication number: WO2024105165A1
Application number: PCT/EP2023/082061
Authority: WO
Inventors: Søren Maribo; Mathias Jensen
Original assignee: People2Play Aps
Priority date: 2022-11-17
Filing date: 2023-11-16
Publication date: 2024-05-23
Also published as: EP4371629A1

Abstract

A self-inflating ball comprising an enclosed volume, the enclosed volume having an opening which allows air to move into and out of the enclosed volume, the self-inflating ball comprising individual panels that are connected together such that the individual panels together define the enclosed volume, the opening having area of from 30 mm2 to 51 mm2, characterised in that the material used to make the panels is a woven material having a thread count of at least 200 threads per square inch; having a basis weight of from 20 to 60 g/m2; and the woven material being woven from 30 to 50 denier yarn.

Description

Self-inflating ball for play

The present disclosure relates to a self-inflating ball suitable for indoor games and play, and a method for making the same.

Background to the invention

Self-inflating balls made from lightweight paper are known, particularly from Japanese culture where they are typically called "kamifusen". Smaller kamifusen are traditional children's toys in Japan.

A kamifusen is typically made from glassine paper known as washi, which is airresistant, glossy and thin, having sufficient plasticity to allow it to be formed into a new shape which it can then retain. A kamifusen will have a small opening which allows air to freely enter and exit, allowing the kamifusen to be inflated either by blowing through the hole or by self-inflating via repeatedly hitting the kamifusen, for instance with a hand.

The physics behind how a kamifusen self-inflates has been studied and shown to be reliant on the elasticity of the material sucking air into the enclosure after it has been hit. Thus, hitting a kamifusen (for instance with the palm of a hand) will compress the structure, expelling air from the enclosed space. The elastic rebound following the hit will then draw air into the enclosure. It has been shown that the time period during the elastic rebound is typically longer than the time under compression, which results in a net influx of air into the kamifusen. This leads to the interesting result that kamifusens are self-inflating and will stay inflated when repeatedly hit with a certain force.

While traditional kamifusens are often used for play, they typically cannot be used for any games which rely on vigorous hitting as they easily break when hit too hard. There is therefore a need for self-inflating balls which can be used for indoor games involving vigorous hitting.

Summary of the invention

According to a first aspect of the present disclosure, there is provided a self-inflating ball comprising an enclosed volume, the enclosed volume having an opening which allows air to move into and out of the enclosed volume, the self-inflating ball comprising individual panels that are connected together such that the individual panels together define the enclosed volume, the opening having area of from 30 mm² to 51 mm², characterised in that the material used to make the panels is a woven material; having a thread count of at least 200 threads per square inch; having a basis weight of from 20 to 60 g/m²; and the woven material being woven from 30 to 50 denier yarn.

In one or more embodiments, the enclosed volume may be from 900 cm³ to 1440 cm³.

In one or more embodiments, the ball may have a diameter of from 125 mm to 135 mm.

In one or more embodiments, the opening may be a circular hole having a diameter of from 6.5 mm to 7.5 mm.

In one or more embodiments, the fabric may have a thread count of from 250 to 400 and a basis weight of from 30 g/m² to 50 g/m².

In one or more embodiments, the inner surface of the ball may be coated with a polymer.

In one or more embodiments, from 50% to 95% of the outer surface of the ball may be coated with a silk ink.

In one or more embodiments, the individual panels may comprise 12 pentagons of equal size, preferably wherein the ball is a dodecahedron.

In one or more embodiments, the individual panels may be connected via stitching.

In one or more embodiments, the opening may be present on a face of the ball.

In one or more embodiments, the opening may be between at least any two panels.

According to second aspect of the present disclosure, there is provided a method of manufacturing a self-inflating ball comprising: receiving a plurality individual panels, wherein one of the received individual panels comprises an opening having area of from 30 mm² to 51 mm²; coupling the individual panels together in order to provide an enclosed volume defined by the individual panels, wherein the material used to make the panels is a woven material having a thread count of at least 200 threads per square inch; having a basis weight of from 20 to 60 g/m²; and the woven material being woven from 30 to 50 denier yarn.

In one or more embodiments, the method comprises coupling the individual panels together by stitching, wherein the majority of the panels are coupled together to provide structure having an inner surface and an outer surface, the structure is inverted such that the inner surface and outer surface exchange with one another, and the remaining panels are coupled to provide the self-inflating ball. Preferably, all-but-one panels are coupled prior to inverting the structure.

Brief Description of the Drawings

One or more embodiments will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a photograph of the self-inflating ball of the disclosure; and

Figure 2 is a graph showing the number of hits to achieve self-inflation of a 128 mm ball having different hole sizes.

Detailed Description

The present disclosure relates to a self-inflating ball comprising an enclosed volume, the enclosed volume having an opening which allows air to move into and out of the enclosed volume. Figure 1 shows an exemplary self-inflating ball according to the disclosure.

It will be appreciated that the enclosed volume is fully enclosed apart from the presence of the opening. That is, the enclosed volume is a substantially enclosed volume.

As used herein, by "self-inflating" is meant an object that will inflate and stay inflated when repeatedly hit, for instance by hitting with a suitable flat surface such as a hand, bat or racket.

By "inflate" is meant that the object increases its internal volume. In the present disclosure, the surface area of a self-inflating object does not change when it becomes inflated. In other words, the surface of the self-inflating ball does not stretch or expand when the ball inflates. Rather, the material of the ball rearranges its shape such that the internal volume of the ball increases.

A self-inflating ball is fully inflated when the internal volume of the ball is maximised without the surface area of the ball increasing. In other words, the material from which the ball is made is not under so much tension that it becomes stretched. Rather, the material is under sufficient tension that the internal volume cannot be increased unless the material is stretched. A self-inflating ball does not necessarily fully inflate with a single hit. In fact, it often requires a number of hits to reach full inflation, for instance at least 5 hits or at least 10 hits.

The specific technique used to inflate a self-inflating ball is not critical. However, best results are achieved when a flat surface is used to hit the ball that is typically comparable to or larger than the diameter of the ball. If a very narrow surface strikes the ball (that is, the surface of the striking surface is small in comparison to the ball), this can lead to the energy imparted to the ball being focussed in a narrow area, making it unlikely that the elastic rebound force will draw in the same or more air than was expelled when the ball was hit. In contrast, if a broad, flat striking surface is used, the energy imparted to the ball is dissipated over a large area increasing the effectiveness of the elastic rebound force at reshaping the ball and drawing in air.

The self-inflating ball of the present disclosure is made from a material that provides a good balance of strength, elasticity and weight, such that the ball is able to selfinflate, has sufficient strength to allow it to be struck with force, and sufficient weight to allow it to travel longer distances than a traditional paper kamifusen. The selfinflating ball of the present disclosure can therefore be used for play and games where a traditional paper kamifusen would not be suitable.

The self-inflating ball typically has a diameter of from 110 mm to 150 mm, preferably from 120 mm to 140 mm, more preferably from 125 mm to 135 mm, most preferably from 126 mm to 130 mm.

By "diameter" is meant the largest distance from one external edge to the other when the ball is fully inflated.

The self-inflating ball need not be exactly spherical. Due to the construction of the ball, it very often has a pseudo-spherical shape such as an icosahedron, a dodecahedron or similar geometric shapes.

Non-spherical shapes may also be used, providing that they have an enclosed volume commensurate with a sphere having a diameter of from 110 mm to 150 mm, preferably from 120 mm to 140 mm, more preferably from 125 mm to 135 mm, and most preferably from 126 mm to 130 mm. That is, the enclosed volume of the self-inflating ball is preferably from 695 cm³ to 1770 cm³, preferably from 900 cm³ to 1440 cm³, more preferably from 1020 cm³ to 1290 cm³, and most preferably from 1045 cm³ to 1155 cm³.

The self-inflating ball has an opening which is typically circular. Preferably, the circular open hole has a diameter of from 6.2 mm to 8 mm, preferably from 6.5 mm to 7.5 mm, preferably from 6.7 mm to 7.3 mm, most preferably about 7 mm.

The opening does not necessarily need to be circular, and other shapes can be used which have an overall area comparable to the size of the above circles, for instance from 30 mm² to 51 mm², preferably from 33 mm² to 45 mm², preferably from 35 mm² to 42 mm², most preferably about 39 mm².

The self-inflating ball is typically made from individual panels that are connected together, for instance via airtight joints (or seams).

The material used to make the panels is typically a woven material having a thread count of at least 200 threads per square inch (or 79 threads per square centimetre), preferably at least 250 threads per square inch (or 99 threads per square centimetre), for instance from 250 to 400 threads per square inch (99 to 158 threads per square centimetre), preferably from 275 to 350 threads per square inch (109 to 137 threads per square centimetre).

By "thread count" is meant the number of threads in one square inch of fabric, including both length (warp) and width (weft).

The yarn used to make the panels is typically from 30 to 50 denier (33 - 56 dtex), for instance from 35 to 45 denier (38 - 50 dtex).

The fabric typically has a basis weight of from 20 g/m² to 60 g/m², preferably from 25 g/m² to 55 g/m², more preferably from 30 g/m² to 50 g/m², most preferably from 35 g/m² to 45 g/m².

Optionally, the fabric may have stronger fibres included periodically, such as every 4 mm to 10 mm, preferably every 5 mm to 8mm. Such stronger fibres may be higher denier fibres, or may be fibres having very high tensile strength such as ballistic fibres. Fabrics with this weave pattern are typically called ripstop fabrics. Optionally, one or both surfaces of the fabric may be coated with a polymer configured to reduce the air-permeability of the fabric. This can help improve the air tightness of the fabric.

Suitable coating polymers include polyurethane, polyethylene, polypropylene, and fluoropolymer such as polytetrafluoroethylene or polyvinylidene fluoride. Polyurethane is preferred.

Preferably, the inner surface of the ball is coated with a polymer.

The outer surface of the ball may optionally be coated, for instance an ink may be used to provide a decorative pattern on the surface of the ball. Suitable coating inks that can be used include silk screen printing inks.

Coating the ball with ink (such as a silk ink) can be advantageous as it provides extra weight to the ball without needing to rely on a heavier fabric which may not have the right balance of elasticity and flexibility to allow the ball to be self-inflating. This allows the ball to have good float properties, enough weight to travel long distances, yet retain the properties of self-inflation.

Therefore, preferably the outer surface of the ball is coated with a silk ink which comprises from 10 wt% to 50 wt% of the ball, more preferably from 20 wt% to 35 wt% of the ball.

When present, the silk ink does not necessarily cover the entire outer surface of the ball. Rather, the ink is typically printed on one or more of the panels, for instance in a decorative pattern.

Preferably, the ball comprises silk ink coated on from 20% to 95% of its outer surface, for instance from 40% to 95% or more preferably from 50% to 95% of its outer surface.

Suitable materials for the fibres in the fabrics include nylon, polyester, polyethylene, rayon. Preferred materials include nylon and polyester, with nylon being the most preferred.

The panels may be joined together by any suitable means such as stitching, adhesive or thermal bonding. Typically, the panels are stitched together as this provides a strong, durable way of connecting the panels that ensures the ball tolerates repeated hitting. Preferably, the stitching is done using a fine yarn with stitch intervals of less than 2 mm, such as less than 1.5 mm or less than 1 mm, to ensure the joins between the panels are airtight. Adhesive may optionally be used in addition to stitching, which increases the connective strength of the joins and provides a more airtight connection.

By "airtight" in this context is meant joints that prevent air passing through the joint (or seam) under reasonable blowing force from a human, such as air moving at about 10 m/s, preferably about 20 m/s. This ensures that the ball may be readily inflated by blowing through the open hole, and self-inflates when repeatedly hit.

The shapes used to form the ball are not critical, providing that the overall shape of the inflated ball is approximately spherical. Typical shapes that can be used include pentagons (such as 12 equal sized pentagons to form a dodecahedron); pentagons and hexagons (such as 12 pentagons in combination with 20 hexagons to form a truncated icosahedron); triangles (such as 20 equal triangles to form an icosahedron); shapes having four-fold symmetry that combine to provide octahedral symmetry (such as 6, 12 or 18 panels that combine to provide a ball with octahedral symmetry); and segments that combine, for instance like the skin of orange segments, to provide a ball having rotational symmetry about an axis, optionally with end caps to allow easier assembly.

The particular shapes that are used are typically visible in the inflated ball and will often be chosen to provide the best combination of ease of assembly and aesthetics.

Preferred shapes are pentagons (i.e. 12 identical pentagons) as these provide a good balance of shape and symmetry of the inflated ball, and minimum amount of connecting edges which facilitates assembly of the ball. This configuration is shown in Figure 1.

The open hole is typically positioned on a face of the ball, i.e. on a panel away from any connecting edges joining the panels that make up the ball. In some embodiments, the hole may be arranged at a central position on a panel of the ball. That is, where a periphery of a single panel is defined by a plurality of edges extending between a plurality of vertices, the hole may be arranged substantially equidistant from each of the vertices of the panel. This configuration is shown in Figure 1. Alternatively, the open hole may be defined by an opening in the connection between two or more panels, i.e. between at least any two panels.

The self-inflating ball preferably only has one opening.

The open hole may be reinforced, such as with additional panelling to strengthen the hole and reduce the likelihood of any tearing of the material, or with silk ink, or with stitching. Alternatively or additionally, adhesive may be used to reduce the likelihood of the material around the edge of the hole fraying.

Typically, the ball is constructed by stitching together panels until at least one panel remains; turning the ball inside out; and stitching the at least one panel in place to provide the assembled ball. This methodology ensures that the majority of the stitching is internal to the ball, improving the overall aesthetics.

The ball of the disclosure will be further characterised by the following examples.

There is also disclosed a method of manufacturing a self-inflating ball comprising: receiving a plurality individual panels, wherein one of the received individual panels comprises an opening having area of from 30 mm² to 51 mm²; coupling the individual panels together in order to provide an enclosed volume defined by the individual panels, wherein the material used to make the panels is a woven material having a thread count of at least 200 threads per square inch; having a basis weight of from 20 to 60 g/m²; and the woven material being woven from 30 to 50 denier yarn.

Preferably, the method comprises coupling the individual panels together by stitching, wherein the majority of the panels are coupled together to provide structure having an inner surface and an outer surface, the structure is inverted such that the inner surface and outer surface exchange with one another, and the remaining panels are coupled to provide the self-inflating ball. More preferably, all-but-one panels are coupled prior to inverting the structure.

Example 1 - Strength test vs. Kamifiisen

Paper kamifusens were repeatedly hit with a hand using hard force against a wall either 60 cm or 90 cm away. The number of hits taken until the kamifiisen ruptured and was no longer self-inflating were noted. The results are reported in Table 1:

Ball 2 from the large diameter group was defective so would not self-inflate before testing.

The results show that the larger diameter kamifusen is less robust and not able to withstand as many hard hits.

The test was repeated with a self-inflating ball according to the disclosure with a diameter of 128 mm, formed from lightweight nylon ripstop fabric stitched together as 12 pentagons. The ball could not be broken and retained the ability to self-inflate even after 1000+ hits when the testing was stopped.

Example 2 - Time to self-inflate

Self-inflating balls were made from nylon fabric (12 pentagons stitched together) were made with differing opening sizes. The number of hits necessary to fully inflate the ball were measured using the following protocol:

1. The balls were flattened to approximately 1cm thick by pressing them against a flat surface with a tennis racket, trapping the ball between the flat surface and the racket strings.

2. The balls were then repeatedly hit upwards using the tennis racket and the number of hits taken to achieve full inflation were counted.

Steps 1 and 2 were repeated 20 times, and the total number of hits are reported in Figure 2. As can be seen, the 7 mm hole surprisingly was the most suitable size to ensure rapid self-inflation of the ball.

Example 3 - Air velocity in relation to diameter Three self-inflating balls were made from 12 nylon pentagons, with the balls having diameters of 120 mm, 128 mm and 148 mm.

The balls were fully inflated and simultaneously dropped from a height of about 4 m, indoors in still air. The relative air time was recorded by noting the order in which the three balls reached the ground. This test was repeated 10 times, with the medium sized ball (128 mm diameter) hitting the ground last on every occasion (on two occasions, the large diameter ball (148 mm diameter) hit the floor at the same time as the medium diameter ball). The small ball hit the ground first in every test.

The experiment shows that the medium sized ball had the best balance of size and weight to ensure maximum air time. When used in play, a ball having high air time is often desirable since it allows the ball to be hit further and float so a game can be played on a larger scale.

Example 4 - Striking distance

Self-inflating balls having diameter of 128 mm, made from 40 g/m² nylon (40 denier or 44 dtex) fabric having a thread count of 300 (12 pentagons, stitched together). The fabric was coated on one side with polyurethane, used as the inner surface. The outer surface was coated at about 90-95% coverage with silk ink (approximately 32 wt% of the ball). The balls had an opening of 7 mm.

The balls (5 total) were hit for a total of 50 times while fully inflated (10 hits per ball) with a hand from shoulder height (approximately 1.8 m high) indoors in still air. The shot lengths were measured as minimum 3.70 m, maximum 5.44 m, with an average of 4.46 m.

Paper kamifusens were tested using a similar method and could not be made to travel as far as 3.70 m. Moreover, striking paper kamifusens with the same force as used for the nylon self-inflating balls caused them to break.

Conclusion

The examples show that a self-inflating ball according to the disclosure provides an excellent balance of strength, hitting distance (i.e. maximum travel distance on hitting), floating time (i.e. tendency to float and hang in the air after being hit) and speed of self-inflation. These combined factors provide a ball with excellent tactile properties when used in play. In other words, the balls rapidly inflate and have a high tendency to stay inflated, giving them a firm feel during play. These tactile properties combined with the good float properties and long striking distances make the selfinflating balls of the disclosure excellent options for indoor play and games.

Although specific terms may be employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. Therefore, persons skilled in the art would recognize numerous variations to the described embodiments that would still fall within the scope of the appended claims. As used herein, the terms "comprise/comprises" or "include/includes" do not exclude the presence of other elements or steps. Furthermore, although individual features may be included in different claims (or embodiments), these may possibly advantageously be combined, and the inclusion of different claims (or embodiments) does not imply that a certain combination of features is not feasible and/or advantageous. In addition, singular references do not exclude a plurality. Finally, reference numerals in the claims are provided merely as a clarifying example and should not be construed as limiting the scope of the claims in any way.

Claims

Claims.

1. A self-inflating ball comprising an enclosed volume, the enclosed volume having an opening which allows air to move into and out of the enclosed volume, the self-inflating ball comprising individual panels that are connected together such that the individual panels together define the enclosed volume, the opening having area of from 30 mm² to 51 mm², characterised in that the material used to make the panels is a woven material having a thread count of at least 200 threads per square inch; having a basis weight of from 20 to 60 g/m²; and the woven material being woven from 30 to 50 denier yarn.

2. The self-inflating ball of claim 1, wherein the enclosed volume is from 900 cm³ to 1440 cm³.

3. The self-inflating ball of claim 1 or claim 2, wherein the ball has a diameter of from 125 mm to 135 mm

4. The self-inflating ball of any preceding claim, wherein the opening is a circular hole having a diameter of from 6.5 mm to 7.5 mm.

5. The self-inflating ball of any preceding claim, wherein the fabric has a thread count of from 250 to 400 and a basis weight of from 30 g/m² to 50 g/m².

6. The self-inflating ball of any preceding claim, wherein the inner surface of the ball is coated with a polymer.

7. The self-inflating ball of any preceding claim, wherein from 50% to 95% of the outer surface of the ball is coated with a silk ink.

8. The self-inflating ball of any preceding claim, wherein the individual panels comprise 12 pentagons of equal size, preferably wherein the ball is a dodecahedron.

9. The self-inflating ball of any preceding claim, wherein the individual panels are connected via stitching. The self-inflating ball of any preceding claim, wherein the opening is present on a face of the ball. The self-inflating ball of any one of claims 1-9, wherein the opening is between at least any two panels. A method of manufacturing a self-inflating ball comprising: receiving a plurality individual panels, wherein one of the received individual panels comprises an opening having area of from 30 mm² to 51 mm²; coupling the individual panels together in order to provide an enclosed volume defined by the individual panels, wherein the material used to make the panels is a woven material having a thread count of at least 200 threads per square inch; having a basis weight of from 20 to 60 g/m²; and the woven material being woven from 30 to 50 denier yarn.