The present invention relates to a wearable airbag comprising a first side and a second side which are interconnected at a perimetral interface to form an inflatable bag.

Such wearable airbags can be used for instance by motor riders to protect themselves against the impact of a fall or crash. Normally, the wearable airbag is in a deflated state. The inflatable bag is activated only in the event of an accident by means of an inflation device adapted to introduce pressurized medium, e.g. gas into the inflation compartments of the inflatable bag, so as to inflate the inflation compartments.

A problem with such wearable airbags is the breathability of the material used for the airbag. The airbag material hampers airflow along the body and for instance on warm sunny days the motorcyclist may experience high temperatures in his garment, which makes wearing the airbag uncomfortable.

WO 2020/115137 A1 discloses a wearable airbag in which airflow passages are provided between the first side and second side of the wearable airbag to improve airflow through the airbag.

In one embodiment disclosed in WO 2020/115137, the first side and second side are locally sealed together, such that so called non-inflatable areas are created. In these non-inflatable areas an airflow passage is formed. A disadvantage of this embodiment is that non-inflatable areas create a minimal distance between the first and second side of the airbag and therefore do not provide a uniform protection against an impact.

In another embodiment disclosed in WO 2020/115137, the airflow passages are formed by internal partitions, which connect cut-outs provided in the first side and the second side. This internal partition allows a larger distance between the first and second side of the inflatable bag upon inflation of the bag, and thereby a more evenly distributed protection all over the part of the body to be protected. This known wearable airbag providing an even protection has the disadvantage that it is complex to manufacture. A wearable inflatable vest having a similar structure is disclosed in US 9,320,674, wherein Figures 13E and 13F show partition walls formed by hollow tubes connected to the first side and second side of the inflatable bag so as to form an airflow passage. The invention aims to provide a wearable airbag which is able to provide a uniform protection upon inflation, but at the same time is easier to manufacture.

This objective is achieved by a wearable airbag according to claim 1.

The wearable airbag according to the invention is compartmentalized with distributed inflation compartments and one or more ventilation compartments. The inflation compartments are in fluid communication with each other. The one or more ventilation compartments are adjacent to the inflation compartments and are sealed with respect to the inflation compartments such that gas does not flow from the inflation compartments to the ventilation compartment(s). The at least one ventilation compartment has ventilation openings extending through the first side and the second side towards the exterior. The at least one ventilation compartment according to the invention is easier to manufacture than sealing separate tubular walls from one cut-out to an opposite cut-out in the first and second sides, as is the case in the mentioned prior art.

In embodiments the at least one ventilation compartment has multiple ventilation openings extending through each of the first side and the second side towards the exterior. The multiple ventilation openings may be distributed over the length of the ventilation compartment to distribute the ventilation effect.

Ventilation openings in the first side and in the second side are preferably aligned with each other such that in a deflated state of the airbag a direct short flow path for ventilation air from the first side to the second side is made possible.

In possible embodiments foldable tubes and/or baffles may be attached to the first and second side of the airbag to compartmentalize the interior of the airbag.

In a preferred embodiment, the at least one ventilation compartment is formed by a foldable tube, the tube having a first strip-like attachment zone extending over the length of the tube and a second strip-like attachment zone extending over the length of the tube (diametrically) opposite the first attachment zone, wherein the first attachment zone is sealed inside the inflatable bag to the interior side of the first side, and wherein the second attachment zone is sealed to the interior side of the second side, wherein the ventilation openings are provided through the first and second side of the airbag and the tube at the first and second attachment zones, and wherein the tube has sealed ends. In a practical embodiment, the first side and second side of the inflatable bag may be made of a woven fabric layer facing the outside and a plastic layer facing the inside of the bag. The tubes may be made of a woven fabric layer and a plastic layer facing the outside of the tube. The plastic layer of the tube can be sealed, in a sealing area spanning the length of the tube and a certain width of the tube, to the plastic layer of the first side and second side, respectively. In this way two attachment zones are formed on diametrically opposite sides of the tube. These attachment zones and the area of the first and second side, to which they are respectively sealed, are provided with perforations to form ventilation holes such that the ventilation compartment is able to communicate with the exterior on the first side and the second side of the airbag. The tube portions between the sealing areas are folded when the airbag is in a non-inflated state. In this state, the ventilation openings are close to each other. When the airbag is inflated, the tube portions between the sealing areas unfold and will be erected such that they form partition walls between the ventilation compartments and the inflation compartments.

In an embodiment the tubes are formed from one sheet including a fabric layer having a plastic layer on opposite sides of the sheet. The sheet is folded over, and the longitudinal edges are welded together to form the tube. The sheet is thus formed into a tube and the plastic layer along one longitudinal edge is thus welded together with one of the plastic layers along the other longitudinal edge to close the tube.

In another embodiment the tubes are formed from two sheets including a fabric layer having a plastic layer on opposite sides of each of the sheets. The sheets are positioned on top of each other and welded together along the longitudinal edges.

The plastic layer may in practise be of a suitable plastic material which can form an airtight layer, which has a suitable degree of flexibility to be incorporated in garment and which is weldable (HF welding, heat sealing, etc.). In one possible embodiment the plastic layer may be provided on the fabric layer as a coating. Another option is to form a laminate of the fabric layer and the plastic (film) layer. In practise the plastic layer on the first and second side of the inflatable bag and on the tubes will be of the same plastic material, although this is not strictly necessary if the plastic layers are compatible in the sense that they can be welded together.

A preferable plastic material to make the plastic layer on the airbag and the tubes is Polyurethane (Pll). However, also other plastic materials are feasible such as PE, PVC and other thermoplastics which have suitable forming and welding properties. In another preferred embodiment the at least one ventilation compartment and inflation compartments are formed by welding foldable baffles with one longitudinal edge region to the interior side of the first side and with an opposite longitudinal edge region against the interior side of the second side, wherein the ventilation compartments have sealed ends.

Also, in this embodiment, the first side and second side may be formed of a woven fabric provided with a plastic layer. The baffles may be formed of a woven fabric provided with a plastic layer. Opposite longitudinal edge areas of the baffles can be folded and sealed with the plastic layer to the plastic layer of the first side and second side of the inflatable bag, respectively, whereby the interior of the inflatable bag is compartmentalized. In some of the formed compartments, i.e. the ones which are dedicated to becoming ventilation compartments, perforations can be made in the first and second side of the bag to form the ventilation openings.

Also in this embodiment including baffles the plastic layer may in practise be of a suitable plastic material which can form an gastight layer, which has a suitable degree of flexibility to be incorporated in garment and which is weldable (HF welding, heat sealing, etc.). In one possible embodiment the plastic layer may be provided on the fabric layer as a coating. Another option is to form a laminate of the fabric layer and the plastic (film) layer. In practise the plastic layer on the first and second side of the inflatable bag and on the tubes will be of the same plastic material, although this is not strictly necessary if the plastic layers are compatible in the sense that they can be welded together.

A practical example of a plastic material to make the plastic layer on the airbag and the baffles is Polyurethane (Pll). However, also other plastic materials are feasible such as PE, PVC and other thermoplastics which have suitable forming and welding properties.

Also, an embodiment, wherein both foldable tubes and baffles are applied to form the inflation compartments and ventilation compartments is conceivable within the scope of the present invention.

At the ventilation compartment, whether it is defined by the baffles or by a tube, the ventilation openings in the first side and in the second side all communicate with each other via the ventilation compartment.

In another aspect of the invention the tubes and/or baffles are elastic, and the airbag comprises tether members having a low elasticity relative to the tubes and/or baffles. The tether members extend through a number of the ventilation openings, and are associated with the first side and the second side of the airbag to maintain a predetermined distance between the first side and the second side in an inflated state. When the airbag is inflated the tubes and/or the baffles deform elastically, i.e. allow elongation in the thickness direction of the airbag, and do not withhold the first side and second side to move apart. The additional tether members which are non-elastic, or at least have a relatively limited elasticity, perform the function of keeping the first side and second side of the airbag on a certain distance in the inflated state.

In an embodiment wherein the first and/or the second side of the airbag are of a non-elastic material, and the tether members are provided, the airbag will not inflate like a balloon and keep a pre-determined shape defined by the tether members combined with the non-elastic material of the first and second side.

However, in another embodiment, the first side and/or the second side of the airbag may be elastic. The first side and second side are in such an embodiment made only of a plastic material such as Pll, PE or PVC, thus without a fabric layer. The tubes or baffles may be of an elastic material as well. In such an embodiment the wearable airbag may furthermore comprise an exterior harness defining a pocket, in which the inflatable bag is accommodated, wherein the tether members having at least a limited elasticity are connected to the exterior harness. The exterior harness prevents that the elastic airbag inflates like a balloon and defines the outer shape in the inflated state. The harness thus determines the distribution of the protection by the airbag. The harness may be a knitted harness. Opposite sides of the harness are interconnected by the tether members which extend through the ventilation openings in the airbag, thus determining the inflated shape of the airbag.

In a possible embodiment the airbag may be welded, e.g. spot welded to the knitted harness, whereby the gastight membrane is laminated to a knitted fabric.

In yet another embodiment, the first side and/or the second side of the airbag may be elastic. The first side and second side are in such an embodiment made only of a plastic material such as Pll, PE or PVC, thus without a fabric layer. The tubes or baffles may include a non- elastic material such as a fabric, whereby the tubes and the baffles maintain the distance between the first and second side of the inflatable bag. If the pressure is kept low enough the non-elastic baffles or tubes may keep the inflatable bag sufficiently in shape. Tether members can be omitted in such an embodiment. The invention also relates to a method according to claim 16 and a method according to claim 18.

The invention will be further elucidated in the following description with reference to the drawing, wherein:

Fig. 1 shows a view in perspective of an embodiment of a wearable airbag according to the invention,

Fig. 2 illustrates, by a schematic cross section, an embodiment of the wearable airbag according to the invention, having a tube sealed in the airbag, in an inflated state,

Fig. 3 shows a detail indicated by III in Fig. 2,

Fig. 4 illustrates in a view in perspective the embodiment of Fig. 2 in an inflated state,

Fig. 5 illustrates the wearable airbag of Fig. 2 in a non-inflated state.

Fig. 6 illustrates, by a schematic cross section, an embodiment of the wearable airbag according to the invention, having baffles sealed in the airbag, in an inflated state and

Fig. 7 illustrates the embodiment of Fig. 6 in an inflated state in a view in perspective,

Fig. 8 illustrates schematically a cross section of an embodiment of a tube for a wearable airbag according to the invention,

Fig. 9 illustrates schematically a cross section of another embodiment of a tube for a wearable airbag according to the invention,

Fig. 10 illustrates a tube of Fig. 9 sealed in a wearable airbag,

Fig. 11 illustrates in a view in perspective an embodiment of a wearable airbag according to the invention, having tether members and an exterior harness, and

Fig. 12 illustrates in a cross section the wearable airbag of Fig. 11. Fig. 1 shows a front of a wearable airbag 1, which is in an inflated state. The wearable airbag 1 is in this practical embodiment made of two sides 2 and 3, respectively, as is visible in Fig. 2. The sides 2 and 3 each comprise an outer layer of woven fabric 7, which on an inner side has a layer 8 of a plastic material, for example a Polyurethane (Pll) coating, which is visible in the detail of Fig. 3. The sides 2 and 3 are gastight.

In the cross section of Fig. 2 a preferred embodiment of the principal structure of the airbag 1 is shown. In this embodiment the first side 2 is in use facing outwardly and a second side 3, in use, faces the body of the person wearing the airbag 1. The first side 2 and second side 3 are interconnected at a perimetral interface 9 to form an inflatable bag, e.g. by welding the plastic layers 8, in the example the Pll coatings 8, of the two sides 2 and 3 together.

As can be clearly seen, the inflatable bag comprises one or more inflation compartments 4, which are interconnected and are in fluid communication with each other (cf. Fig.1 ). In the main panel of the wearable airbag the inflation compartments 4 are arranged alternately with ventilation compartments 5. In the example of Figs. 2 and 4 there are two inflation compartments 4 and one intermediate ventilation compartment 5. The ventilation compartment 5 is sealed with respect to the inflation compartments 4 and has multiple ventilation openings 6 extending through the first side 2 towards the exterior and multiple ventilation openings 6 extending through the second side 3 towards the exterior.

In the embodiment of Figs. 2 and 4, the ventilation compartment 5 is created in the inflatable bag by arranging a foldable tube 10 inside the inflatable bag between the two layers 2 and 3. The foldable tube 10 has a first longitudinal, strip-like zone 11 which is attached to the first side 2, and it has a second longitudinal, strip-like zone 12, opposite the first zone 11 , which zone 12 is attached to the second side 3.

The attachment between the opposite zones 11 and 12 of the tube 10 and the respective sides 2 and 3 of the of the airbag may be sealed, by a sealing technique, e.g. heat sealing, ultrasonic welding or HF welding. In a possible embodiment the tube may have a layer of woven fabric and an outer coating of Pll. The outer coating of Pll of the tube is compatible with the inner Pll coating 8 of the airbag and the two Pll layers may be fused by one of the sealing/welding techniques at the zones 11 and 12 of the tube 10.

After the tube 10 is sealed inside the airbag, the tube 10 defines a compartment 5 in its interior which is sealed from the adjacent compartments 4 which are defined by the tube wall portions 13 and 14 extending between the strip-like zones 11 and 12. Perforations are provided through the first side 2 of the airbag and the associated zone 11 of the tube 10 and through the second side 3 and the associated zone 12 of the tube 10 after these zones 11 and 12 are sealed/welded to the inner side of the first and second side 2 and 3, respectively. In this way the inflatable compartments 4 are by definition sealed airtight from the ventilation openings 6.

In the non-inflated state, the first side 2 and second side 3 are lying against each other or are close to each other and the tube wall portions 13 and 14 are in a collapsed state, which is illustrated in Fig. 5. The perforations 6 in the opposite sides 2 and 3 are in the non-inflated state close to each other, more or less aligned, and the ventilation air, indicated by arrows in Fig. 5, can flow directly from one ventilation opening 6 to the opposite ventilation opening 6. This provides the predominant ventilation effect in the deflated state. However, the ventilation openings 6 on one side are in fluid communication with the other ventilation openings 6 via the interior space of the ventilation compartment 5, even in the non-inflated state, which may provide an additional ventilation effect.

In an inflated state, which is shown in Figs 2 and 4, the ventilation openings 6 on one side are in fluid communication with the other ventilation openings 6 via the interior space of the ventilation compartment 5. As indicated by arrows in Fig. 2, air flows into the ventilation compartment 5 through one ventilation opening 6 and may flow out of the ventilation compartment 5 through an opposite ventilation opening 6. The flow direction may be different as shown in the figure, though.

It is noted that the perforations do not only provide a passage for ventilation air, but also provide a passage for leading perspiration moisture away from the body.

In a practical embodiment the tube is made of a sheet including a fabric layer having a Pll coating on opposite sides of the sheet. This is illustrated in Fig. 8. The sheet is folded over, and the longitudinal edges are welded together at 10A to form the tube 10’ by fusing the Pll coating of one side of the sheet together, i.e. the one side of the sheet, that form the inner side of the tube 10’. The other side of the sheet, which forms the outer side of the formed tube 10’ has also a Pll coating which is sealed to the first side 2 and second side 3 of the airbag at 1 T and 12’ as is indicated in Fig. 8.

In another practical embodiment the tube is made of two sheets including a fabric layer having a Pll coating on opposite sides of each of the sheets. This is illustrated in Fig. 9. The sheets are laid on top of each other. The sheets are welded together by welding together the Pll coating of the sides of the sheets, that form the inner side of the tube 10’ along the edges indicated in Fig. 9 by 10B and 10C. The other side of the sheets, which form the outer side of the formed tube 10” has also a Pll coating which is sealed to the first side 2 and second side 3 of the airbag at 11” and 12” as is indicated in Fig. 9.

Fig. 10 illustrates how a tube 10 can be made by two sheets wherein the circumferential seal connecting the two sheets of the tube is indicated by 10D. The circumferential seal 10D thus comprises the seals 10B and 10C indicated in Fig. 9. The circumferential seal 10D has a closed contour, whereby the interior of the tube 10 is sealed from the exterior. The strip which is sealed to one of the sides 2 or 3 of the airbag is indicated by 10E. In this strip 10E the perforations 6 are indicated, which are made after the tube is sealed to the sides 2 and 3 of the airbag.

In Figs. 6 and 7 another possible embodiment of a wearable airbag construction is illustrated. In this embodiment the airbag 101 has two sides 102 and 103, respectively, each comprising an outer layer of woven fabric, which on an inner side has a thermoplastic coating of for example Polyurethane (Pll), just like is shown in detail in Fig. 3. The sides 102 and 103 are gastight.

The first side 102 and second side 103 are interconnected at a perimetral interface 109 to form an inflatable bag, e.g. by welding the Pll coatings of the two layers 102 and 103 together.

Inside the airbag a plurality of baffles 110 is sealed with a longitudinal edge region 111 to the interior side of the first side 102 and with an opposite longitudinal edge region 112 against the interior side of the second side 103. The baffles 110 may be made of a woven textile having a Pll coating on at least one side, which structure is gastight. By applying the Pll coating of the baffle 110 against the Pll coating of the first side 102 and second side 103 at the folded edge regions 111 and 112, the Pll coatings can be fused by a suitable welding method such as heat sealing or HF welding.

The baffles 110 are arranged in a spaced apart manner, whereby inflation compartments 104 and ventilation compartments 105 are defined between the baffles 110. The inflation compartments 104 are interconnected (cf. inflation compartments 4 in Fig. 1) and thereby in fluid communication with each other, to inflate the compartments 104 well distributed. The ventilation compartments 105 have closed ends such that they are sealed from the other compartments 104. At the ventilation compartments 105 perforations are provided in the first and second sides 102 and 103 which define ventilation openings 106.

Like in the other embodiment of Figs 2 and 4, in the non-inflated state, the first side 102 and second side 103 are lying against each other or are close to each other and the baffles 110 are in a collapsed state. The perforations 106 in the opposite sides 102 and 103 are in the non-inflated state close to each other and the ventilation air or perspiration air can flow directly from one ventilation opening 106 to the opposite ventilation opening 106. In an inflated state, which is shown in Figs. 6 and 7, the ventilation openings 106 on one side are in fluid communication with the other ventilation openings 106 via the interior space of the ventilation compartment 105.

It is noted that the baffles 110 and the tube wall portions 13, 14 have a sealing function, making the inflation compartments 4, 104 gas tight with respect to the intermediate ventilation compartments 5, 105. However, the baffles 110 and the tube wall portions 13, 14 also have a function to keep the first sides 2, 102 and the second sides 3, 103 at a predetermined distance from each other in the inflated state, such that an evenly distributed thickness of the inflatable bag is achieved, which provides an evenly distributed protection.

In another embodiment of the invention the tubes or the baffles may not be made of a fabric coated with at least one plastic layer, such as Pll, but may be made only of a plastic material, such as Pll or other weldable gastight material, e.g. PE or PVC. A tube or a baffle made of for example Pll is much more elastic than a fabric coated with Pll. This has implications when the airbag is inflated, because the tube or baffle will stretch, whereby the distance between the first and second sides in the inflated state is not so well defined anymore. In such an embodiment the airbag may comprise tether members having a low elasticity relative to the tubes and/or baffles. The tether members extend through a number of the ventilation openings 206 as is shown in Figs. 11 and 12. The tether members 231 are associated with the first side 202 and the second side 203 of the airbag to maintain a predetermined distance between the first side 202 and the second side 203 in an inflated state. The tether members 231 may be part of a limiting strip 230 which is laced through different ventilation openings 206, as is shown in Fig. 11. The limiting strip 230 extends in transverse direction over the inflation compartments 204 and the ventilation compartments 205.

In the embodiment, which is shown in Figs. 11 and 12, the first layer 202 and second layer 203 of the airbag itself may not be of a fabric coated with Pll, but instead the first layer 202 and second layer 203 may be made of Pll. The tubes are indicated by 210. In Fig. 11 end closures 211 of the tubes 210 are shown. In such an embodiment not only the tubes 210 or baffles are elastic, but also the first side 202 and second side 203 of the airbag itself. To prevent ballooning of the inflation compartments 204 of the airbag, an exterior harness 220 may be provided around the inflatable bag as is illustrated in Figs. 11 and 12. The exterior harness 220 may be made of a material having a relatively limited elasticity or no elasticity, such that when the elastic airbag inflates, the elastic airbag adopts the shape determined by the exterior harness 220. The exterior harness may be a knitted harness, which allows air to flow through, but which has a limited elasticity. Limiting strips 230 extend through the ventilation openings 206 and can be combined with and connected to the harness 220.

From the latter embodiment it becomes clear that the ventilation openings do not only have a function to provide air flow to transport heat and moist away from the body, but also provide a structural feature allowing limiting strips or tether members to extend through the airbag, such that complex internal structures are avoided whilst allowing for pre-determined limitations upon inflation.

It is noted that if the first side 202 and second side 203 do comprise a fabric layer, which provides these sides 202 and 203 with a limited elasticity or no elasticity, the exterior harness 220 may be omitted. In that case only the effect of elastic tube 210 has to be compensated by tether members 231.

It is noted that in the specific embodiments described here by way of example, sometimes is referred to a woven fabric. It is to be understood though, that this is just one of the practical options of a fabric. It is for example also possible to use a knitted fabric.

Furthermore it is noted that in the embodiments described here by way of example, of the is referred to Pll as a suitable gastight thermoplastic material. It is to be understood though, that this is just one of the practical options of a suitable thermoplastic material. It is for example also possible to use PE or PVC or other thermoplastic materials with suitable gastight and welding properties.