TECHNICAL FIELD

The present invention relates to a ventilation element for an article of apparel or footwear or for a sports accessory.

PRIOR ART

Ventilation elements are ubiquitous in various types of apparel, footwear or in sports accessories. For example, ventilation elements are fitted to the backside of a backpack in order to improve the ventilation of the back of an athlete wearing the backpack.

One known type of ventilation element for a backpack creates a gap between the back of the athlete and the backside of the backpack to improve the circulation of air between the back of the athlete and the backside of the backpack. EP 2 407 050 B1 discloses a frame arrangement concavely tensioning the backwall of a backpack and a net part extending in a sinew-like manner over the concave tensioned back wall. A disadvantage of such a system is the increased weight due to the frame, which is usually made from aluminium, and the complexity of assembly and therefore the increased cost of the backpack. Moreover, the frame itself must necessarily be rigid and so this type of ventilation element does not adapt well to different shapes of a body, for example due to different postures when exercising. This type of ventilation element can also not be used in locations where the ventilation element itself should be elastically stretchable. It may, for example be desired to fit a ventilation element to the straps of a backpack that allows the straps to remain elastically stretchable, for example to absorb shocks that the athlete would otherwise experience from a bouncing backpack, for example during running. Finally, this known construction has the disadvantage that the centre of mass of the backpack is a long distance away from the centre of mass of the athlete, therefore creating an imbalance during exercise.

US 2005/0040684 A1 discloses a cushion member attached to a portion of a bag were a body of user contacts when the bag is used. The cushion member includes an uneven surface portion formed from a plurality of elastic projections. However, the production of the cushion member described by US 2005/0040684 A1 is relatively complicated as it involves molding.

It is therefore an objective underlying the present invention to provide a ventilation element for an article of apparel or footwear or for a sports accessory that is simple to produce, that is adaptable to different body shapes and postures, and that allows shocks to be absorbed.

SUMMARY OF THE INVENTION

This object is accomplished by the teachings of the independent claims and in particular by a ventilation element for an article of apparel, footwear, or a sports accessory, comprising: a first surface, comprising a foam; a second surface; wherein the first surface and the second surface are spaced apart, creating a void, so that air may circulate between the first surface and the second surface.

An article of apparel may, for example, be a pair of trousers, shorts, a shirt, a jacket, or a top. An article of footwear may be a shoe, for example a running shoe, a tennis shoe, or a football boot. A sports accessory may be a backpack, a protective element such as a shinguard, a knee protector, an elbow protector, or a shoulder protector.

The first surface may contact a body part (or clothing, e.g. a shirt, worn by an athlete) directly or indirectly during normal use of the article of apparel, footwear, or the sports accessory. The second surface may contact a contacting portion of the article of apparel, footwear, or the sports accessory during normal use. A contacting portion may be any portion of the article of apparel, footwear, or the sports accessory. For example, for a backpack, a contacting portion may be a backside of the backpack that would, during normal use, be in contact with the back of the athlete. A contacting portion may also be a side of a strap of a backpack that, during normal use, would contact part of the shoulders or upper body of an athlete wearing the backpack. It is not necessary that the ventilation element is arranged between the contacting portion and the body part during normal use. Therefore, the first surface may only indirectly contact the body part. However, it is possible that the ventilation element is arranged between the contacting portion and the body part (or clothing, e.g. a shirt, worn by an athlete) during normal use.

It is to be understood that the spacing between the first surface and the second surface is to be determined in an equilibrium state, without the application of any force, apart from gravity.

The void is the entire space created by spacing apart the first surface and the second surface. The spacing is determined as the spacing between a plane in which the first surface is located and a plane in which the second surface is located. In other words, a lateral separation between the first surface and the second surface is not considered to add to the spacing between the first surface and the second surface. The minimum spacing between the first surface and the second surface is considered to be the sum of the thickness of the first surface and the thickness of the second surface. At this minimum spacing, there is no void. The void may or may not be one connected region.

The ventilation element according to the present invention is lightweight, cushioning, and adaptable since it comprises a foam. The foam may be elastic. Moreover, air may circulate between the first surface and the second surface, providing a comfortable level of ventilation to the athlete.

The first surface may have a first surface area and the second surface may have a second surface area and the ratio of the first surface area and the second surface area may be between 0.2 and 5, preferably between 0.5 and 2, most preferably between 0.75 and 1.33. A small first surface area, compared to the second surface area, leads to better ventilation properties. However, there is a trade-off because for a heavy article of apparel, footwear, or a sports accessory, a first surface area that is too small may be not sufficiently strong to support the weight of the article of apparel, footwear, or sports accessory. The inventors have found that a ratio not too far from unity provides ideal ventilation and stability.

The first surface and the second surface may be arranged to form a first channel in the void. The first channel may be arranged substantially along a longitudinal direction of the ventilation element. For example, for a backpack, a longitudinal direction may be essentially along a vertical direction when the backpack is worn in an upright posture. Essentially along a vertical direction means in this context, extending in the direction from a bottom end of the backpack to a top end of the backpack but allowing for a sideways deviation of up to 30°, preferably 20°.

The inventors have found that the dynamic movement of the athlete causes a chimney effect in the first channel, thus substantially improving the ventilation provided by the ventilation element. For example, the dynamic movement of the athlete, combined with the cushioning and elastic properties of the foam, may cause the spacing between the first surface and the second surface to vary dynamically during use, thereby creating a “breathing” effect.

The first channel may extend substantially from one end of the article of apparel, footwear, or the sports accessory to another end. For example, the first channel may extend substantially from a bottom end to a top end. “Substantially” in this context means at least 60% of the length, preferably 80%, most preferably 90%.

The first channel may have a first width at a first end, a second width at a second end, and a third width at a location between the first end and the second end. For example, the first channel may have a third width at a location arranged in the middle between the first end and the second end.

The first width may be greater than the third width and the second width may be greater than the third width. The inventors have found, that this improves the ventilation provided by the ventilation element as the air circulation is improved by a greater capability for air intake and exhaust at the first end and the second end. At the same time, it is advantageous if the second width is smaller than the first width and the third width, as it improves the adaptability of the ventilation element. Generally, the width of the first channel is to be measured in a direction perpendicular to a longitudinal direction of the channel and in a plane parallel to the first surface.

The ventilation element may comprise a second channel. The second channel may have the same properties as the first channel described herein. The inventors have found, that the ventilation properties and the adaptability of the ventilation element is improved by forming a second channel. In general, the ventilation element may comprise any number of channels.

The second channel may be substantially parallel to the first channel. Substantially parallel in this context means within an angle of +/−10°. Arranging the second channel substantially parallel to the first channel simplifies the construction of the ventilation element.

The first channel may be arranged at a first distance from the second channel at a first end, a second distance from the second channel at a second end, and a third distance from the second channel at a location between the first end and the second end. For example, the first channel may be arranged at a third distance from the second channel at a location in the middle between the first end and the second end. The first distance and the second distance may be greater than the third distance. In other words, the distance between the first channel and the second channel is greater at the first end and the second end than at a location in between the first end and the second end. Therefore, the first channel and the second channel may not be substantially parallel to each other. In this arrangement, a first angle that the first channel makes with a vertical direction at the first end of the first channel may be different to a second angle that the first channel makes with the vertical direction at the second end of the first channel. The inventors have found, that this arrangement improves the ventilation provided by the ventilation element. The reason for this is that this arrangement provides a range of angles for air intake and exhaust. When the athlete is moving dynamically, a greater range of angles for air intake and exhaust therefore improves the ventilation properties of the ventilation element.

The ventilation element may comprise a first bridge and a second bridge; wherein the first surface is an outward-facing surface of the first bridge and the second surface is an inward-facing surface of the second bridge. A bridge in the present context is any construction comprising a low portion and a raised portion. The separation of the low portion and the raised portion, measured from outer surface to outer surface, is referred to as the height of the bridge. The first surface may be an outward-facing surface of the raised portion of the first bridge. The second surface may be an inward-facing surface of a low portion of the second bridge. The inventors have found that this construction is simple to produce, easily adapts to different body shapes and postures, and provides good ventilation and cushioning.

The first bridge and the second bridge may be arranged adjacent to each other. In particular, the low portion of the first bridge may be arranged at the same level as the raised portion of the second bridge. In this case, the spacing between the first surface and the second surface is given by the sum of the height of the first bridge plus the height of the second bridge plus the thickness of the raised portion of the first bridge plus the thickness of the low portion of the second bridge.

It is advantageous to arrange the first bridge adjacent to the second bridge as it allows a simple geometry to be constructed in which air may flow in all three spatial directions thus improving the ventilation properties of the ventilation element.

The first bridge may extend outwards and the second bridge may extend inwards. Outwards means in this case towards the body part and inwards means in this case towards the article of apparel, or footwear, or the sports accessory.

The arrangement of the first and the second bridge may be symmetrical. The ventilation element may comprise a symmetry axis, and the second bridge may be essentially identical to the first bridge but rotated by 180° around the symmetry axis. Essentially identical means in this case the height of the first bridge and height of the second bridge may not be identical. Generally, however, the height of the first bridge and the height of the second bridge may be identical. Moreover, some other differences may result from manufacturing imperfections.

The ventilation element may comprise a plurality of first bridges and a plurality of second bridges arranged to extend outwards and inwards in an alternating manner.

Such an arrangement of a first bridge and a second bridge is particularly simple to produce and provides excellent ventilation uniformly throughout the ventilation element.

A spacing along an outward-facing direction between the first surface and the second surface may be at least 0.5 cm and no more than 5 cm, preferably at least 1 cm and no more than 3 cm. Generally, the larger this spacing is, the better is the circulation of air and therefore the better of ventilation properties of the ventilation element. However, a larger spacing also implies a larger spacing between the centre of mass of the article of apparel of footwear all the sports accessory, for example the centre of mass of a backpack, and the centre of mass of the athlete wearing the article of apparel or footwear or carrying the sports accessory. This may create an imbalance and may be ergonomically undesirable.

A thickness of the first bridge and/or the second bridge may be between 0.5 mm and 20 mm, preferably between 1 mm and 10 mm, most preferably between 2 mm and 5 mm. The thickness affects the bending stiffness of the first bridge/second bridge. The thicker the first bridge/second bridge, the larger is the bending stiffness for bending in the direction of the thickness. If the bending stiffness is too great, the ventilation element does not adapt well to different body shapes or postures. The thickness also affects the cushioning properties of the ventilation element. The thicker the first bridge/second bridge, the better the cushioning properties of the first bridge/second bridge. Therefore, there is a trade-off between bending stiffness on the one hand and cushioning properties on the other hand.

The second surface may also comprise the foam. While the second surface may not normally be in contact with the body part of the athlete, the overall cushioning properties are improved if the second surface also comprises the foam.

The foam may comprise a thermoplastic polymer. A thermoplastic polymer is a polymer that melts or softens under application of heat. A foam comprising a thermoplastic polymer is lightweight, cushioning, and may be easily manufactured.

The foam may have a hardness of 10-80 Shore A, preferably 20-60 Shore A, most preferably 50-60 Shore A. The hardness of the foam is an important criterion for determining its cushioning abilities. If the foam is too hard, the ventilation element is uncomfortable. However, if the foam is too soft, then when a load is applied to the ventilation element, for example due to the dynamic movement of an athlete during exercise or due to the weight of the article of apparel, footwear or the sports accessory, the foam will be compressed to easily leading to a deterioration in the ventilation properties. For example, the spacing between the first surface and the second surface may be reduced to much, if the foam is too soft.

The foam may have a density of between 25 and 400 kg per cubic meter, preferably between 50 and 250 kg per cubic meter, most preferably between 150 and 200 kg per cubic meter. The density of the foam determines its weight, for a given volume. Therefore, generally a denser foam will also be heavier. However, the density of the foam also determines its abrasion resistance. A denser foam will generally be more resistant to abrasion.

The foam may have an elongation at break of at least 50%, preferably at least 75%, most preferably at least 150%. Especially for sports use, it is preferable for the foam to have a large elongation at break. This way, the ventilation element may help to absorb shocks resulting from the dynamic movement of the athlete without tearing or breaking.

The foam may have an elastic modulus of 1 to 100 MPa, preferably between 1 and 5 MPa, most preferably between 1 and 2 MPa. The elastic modulus, also known as Young's modulus indicates how stretchable, or elastic, material is. A large elastic modulus indicates a low level of elasticity, while a small elastic modulus indicates a high level of elasticity. Especially for sports use, it is preferable for the foam to have a relatively small elastic modulus. This way, the ventilation element may help to absorb shocks resulting from the dynamic movement of the athlete.

The foam may comprise ethyl vinyl acetate, also known as EVA. EVA may be thermoformed in an accessible temperature range and the ventilation element is therefore easy to produce.

The ventilation element may be a single unitary piece. This way, the construction of the ventilation element the simplified and there are no potential weak spots at which different elements are joined, thus improving the stability of the ventilation element.

The sports accessory may be a backpack and the ventilation element may comprise a recess arranged along a longitudinal direction of the backpack. The recess may be for receiving a portion of the spine that protrudes from the back of the athlete. The wearing comfort of the ventilation element is improved, since it may not directly contact the spine. Preferably the recess is at least 20 cm long, more preferably at least 30 cm. Preferably, the recess is at least 2 cm wide, more preferably at least 4 cm. This way, even during dynamic movement of the athlete, the ventilation element may generally not be in direct contact with the spine.

The invention further concerns an article of apparel, footwear, or a sports accessory comprising a ventilation element as described herein. The article of apparel, footwear or the sports accessory benefits from the advantageous features of the ventilation element described herein.

The invention further concerns a method of producing a ventilation element for an article of apparel, footwear, or a sports accessory, comprising:

forming a first surface, comprising a foam;

forming a second surface; forming a spacing between the first surface and the second surface to create a void, so that air may circulate between the first surface and the second surface.

The present invention provides a simple method for producing a ventilation element that is lightweight, cushioning, and adaptable. Moreover, air may circulate between the first surface and the second surface, providing a comfortable level of ventilation to the athlete.

The first surface may have a first surface area and the second surface may have a second surface area and the first surface and the second surface may be formed such that the ratio of the first surface area and the second surface area is between 0.2 and 5 preferably between 0.5 and 2, most preferably between 0.75 and 1.33. A small first surface area, compared to the second surface area, leads to better ventilation properties. However, there is a trade-off because for a heavy article of apparel, footwear, or a sports accessory, a first surface area that is too small may be not sufficiently strong to support the weight of the article of apparel, footwear, or sports accessory. The inventors have found that a ratio not too far from unity provides ideal ventilation and stability.

Forming a spacing between the first surface and the second surface may comprise the application of heat and/or pressure. Such a method may be described as thermoforming. For example, a sheet of foam may be pressed and heated in a form in order to form a spacing between the first surface and the second surface. This method has the advantage that lower temperatures may be used then, for example in injection molding.

Forming a spacing between the first surface and the second surface to create a void may comprise forming a first channel. The first channel may be arranged substantially along a longitudinal direction of the ventilation element. For example, for a backpack, a longitudinal direction may be essentially along a vertical direction. Essentially along a vertical direction means in this context, extending in the direction from a bottom end of the backpack to a top end of the backpack but allowing for a sideways deviation of up to 30°, preferably 20°.

The inventors have found that the dynamic movement of the athlete causes a chimney effect in the first channel, thus substantially improving the ventilation provided by the ventilation element. For example, the dynamic movement of the athlete, combined with the cushioning and elastic properties of the foam, may cause the spacing between the first surface and the second surface to vary dynamically during use, thereby creating a “breathing” effect.

The method may comprise extending the first channel substantially from one end of the article of apparel, footwear, or the sports accessory to another end. For example, the first channel may extend substantially from a bottom end to the top end. “Substantially” in this context means at least 60% of the length, preferably 80%, most preferably 90%.

The first channel may have a first width at a first end, a second width at a second end, and a third width at a location between the first end and the second end. For example, the first channel may have a third width at a location arranged in the middle between the first end and the second end.

The first width may be greater than the third width and the second width may be greater than the third width. The inventors have found, that this improves the ventilation provided by the ventilation element as the air circulation is improved by a greater capability for air intake and exhaust at the first end and the second end. At the same time, it is advantageous if the second width is smaller than the first width and the third width, as it improves the adaptability of the ventilation element. Generally, the width of the first channel is to be measured in a direction perpendicular to a longitudinal direction of the channel and in a plane parallel to the first surface.

The method may further comprise, forming a second channel in the ventilation element. The second channel may have the same properties as the first channel described herein. The inventors have found, that the ventilation properties and the adaptability of the ventilation element is improved by forming a second channel.

The method may comprise arranging the second channel to be substantially parallel to the first channel. Substantially parallel in this context means within an angle of +/−10°. Arranging the second channel substantially parallel to the first channel simplifies the construction of the ventilation element. In general, the ventilation element may comprise any number of channels.

The method may comprise arranging the first channel at a first distance from the second channel at a first end, a second distance from the second channel at a second end, and a third distance from the second channel at a location between the first end and the second end. For example, the first channel may be arranged at a third distance from the second channel at a location in the middle between the first end and the second end. The first distance and the second distance may be greater than the third distance. In other words, the distance between the first channel and the second channel is greater at the first end and the second end than at a location in between the first end and the second end. Therefore, the first channel and the second channel may not be substantially parallel to each other. In this arrangement, a first angle that the first channel makes with a vertical direction at the first end of the first channel may be different to a second angle that the first channel makes with the vertical direction at the second end of the first channel. The inventors have found, that this arrangement improves the ventilation provided by the ventilation element. The reason for this is that this arrangement provides a range of angles for air intake and exhaust. When the athlete is moving dynamically, a greater range of angles for air intake and exhaust therefore improves the ventilation properties of the ventilation element.

Forming a first surface may comprise forming a first bridge, wherein the first surface is an outward-facing surface of the first bridge; and wherein forming a second surface comprises forming a second bridge, wherein the second surface is an inward-facing surface of the second bridge. A bridge in the present context is any construction comprising a low portion and a raised portion. The separation of the low portion and the raised portion, measured from outer surface to outer surface, is referred to as the height of the bridge. The first surface may be an outward-facing surface of the raised portion of the first bridge. The second surface may be an inward-facing surface of a low portion of the second bridge. The inventors have found that this construction is simple to produce, easily adapts to different body shapes and postures, and provides good ventilation and cushioning.

The method may further comprise arranging the first bridge and the second bridge adjacent to each other. In particular, the low portion of the first bridge may be arranged at the same level as the raised portion of the second bridge. In this case, the spacing between the first surface and the second surface is given by the sum of the height of the first bridge plus the height of the second bridge plus the thickness of the raised portion of the first bridge plus the thickness of the low portion of the second bridge.

It is advantageous to arrange the first bridge adjacent to the second bridge as it allows a simple geometry to be constructed in which air may flow in all three spatial directions thus improving the ventilation properties of the ventilation element.

Forming a first bridge may comprise forming the first bridge to extend outwards and forming the second bridge may comprise forming the second bridge to extend inwards. Outwards means in this case towards the body part and inwards means in this case towards the article of apparel, or footwear, or the sports accessory.

The first and the second bridge may be formed symmetrically. The ventilation element may be formed to comprise a symmetry axis, and the second bridge may be formed essentially identically to the first bridge but rotated by 180° around the symmetry axis. Essentially identically means in this case that the height of the first bridge and the height of the second bridge may not be identical. However, the height of the first bridge and the height of the second bridge may be identical. Moreover, some other differences may result from manufacturing imperfections.

The ventilation element may be formed to comprise a plurality of first bridges and a plurality of second bridges arranged to extend outwards and inwards in an alternating manner.

Such an arrangement of a first bridge and a second bridge is particularly simple to produce and provides excellent ventilation uniformly throughout the ventilation element.

The second surface may also comprise the foam and forming the first bridge and the second bridge may comprise making a cut in a sheet comprising the foam. While the second surface may not normally be in contact with the body part of the athlete, the overall cushioning properties are improved if the second surface also comprises the foam. Moreover, this allows a simple production of the ventilation element that does not require an injection molding setup. Cutting may be performed by die cutting or laser cutting.

A spacing along an outward-facing direction between the first surface and the second surface may be at least 0.5 cm and no more than 5 cm, preferably at least 1 cm and no more than 3 cm. The advantages of this construction have been explained herein with respect to the ventilation element.

A thickness of the first bridge and/or the second bridge may be between 0.5 mm and 20 mm, preferably between 1 mm and 10 mm, most preferably between 2 mm and 5 mm. The advantages of this thickness have been explained herein with respect to the ventilation element.

The foam may comprise a thermoplastic polymer. A thermoplastic polymer is a polymer that melts or softens under application of heat. A foam comprising a thermoplastic polymer is lightweight, cushioning, and may be easily manufactured.

The foam may have a hardness of 10-80 Shore A, preferably 20-60 Shore A, most preferably 50-60 Shore A. The advantages of this hardness have been explained herein with respect to the ventilation element.

The foam may have a density of between 25 and 400 kg per cubic meter, preferably between 50 and 250 kg per cubic meter, most preferably between 150 and 200 kg per cubic meter. The advantages of this density have been explained herein with respect to the ventilation element.

The foam may have an elongation at break of at least 50%, preferably at least 75%, most preferably at least 150%. The advantages of this elongation have been explained herein with respect to the ventilation element.

The foam may have an elastic modulus of 1 to 100 MPa, preferably between 1 and 5 MPa, most preferably 1 to 2 MPa. The advantages of this elastic modulus have been explained herein with respect to the ventilation element.

The foam may comprise ethyl vinyl acetate, also known as EVA. EVA may be thermoformed in an accessible temperature range and the ventilation element is therefore easy to produce.

The ventilation element may be formed as a single unitary piece. This way, the construction of the ventilation element the simplified and there are no potential weak spots at which different elements are joined, thus improving the stability of the ventilation element.

The invention further concerns a method of producing an article of apparel, footwear, or a sports accessory, comprising producing a ventilation element for the article of apparel, footwear, or the sports accessory, as described herein. The article of apparel, footwear or the sports accessory benefits from the advantageous features of the ventilation element described herein.

