GB2405903A - Hook and loop fastening with bistable support - Google Patents

Abstract

Mechanical fastening, which comprises a first part (1) which is provided with hooks (4), and a second part (5) which has fibres or loops that interact with the hooks to form a hook and loop fastening. The first part (1) is arranged to be able to be changed manually between a first concave state and a second convex state in the first state the hooks (4) being arranged inside a depression in the first part. After changing to the said second state, the said depression is inverted to a protrusion with the hooks (4) accessible for engagement with the fibres or loops in the second part (5). The hook and loop fastening is locked with the hooks (4) engaged in the fibres or loops in the second part (5) when the first part is changed back from the second state to the first state. The fastener can be used on a nappy or the like.

Description

! 2405 903 Mechanical fastening

TECHNICAL FIELD

The present invention relates to a mechanical fastening, which fastening comprises a first part which is provided with hooks, and a second part which has fibres or loops that interact with the hooks to form a hook and loop fastening.

BACKGROUND ART

Mechanical fastenings of the type that are called hook and loop fastenings are known in a large number of embodiments and for use within various fields. Hook and loop fastenings are used as fastenings for clothes, for example as fastenings for securing the sleeves of a jacket around the wearer's wrists. Hook and loop fastenings are currently also used on caps, gloves, footwear, etc. The following will primarily concern embodiments where mechanical fastenings in the form of hook and loop fastenings are used for fastening absorbent disposable products, such as pappies, sanitary towels, panty liners or incontinence pads. Hook and loop fastenings are used for securing the said products around the wearer's body or for fixing them in place on underclothes or special garments that are used in combination with absorbent disposable products.

Hook and loop fastenings consist of a first part with hooks and a second part that has loops or fibres that interact with the hooks. A problem associated with hook and loop fastenings is that, before the hook and loop fastening is used, the hooks can accidentally hook fast onto fibre materials and damage these materials.

In, for example, so-called incontinence pads for adults, it has proved expedient to utilize belts for attaching the incontinence pad to the wearer. As they are disposable products, these belts are manufactured of material that is suitable for disposable use, for example a soft nonwoven material, which forms the inside of the belt and is intended to lie against the wearer's skin, laminated with a backing material intended to withstand tensile stresses. The backing material can also consist of a non-woven material suitable for this purpose, for example a brushed thermally-bonded material such as polypropylene. The said backing material is used as the receiving surface for engagement with the hooks on the male part of a hook and loop fastening. In the use of belt products, it has been found that the hooks on the male part of the hook and loop fastening constitute a considerable problem. During storage of the products before use the belts are folded and the hooks on the male part can accidentally hook fast onto the belt material. When the belt is unfolded for use, there is a danger that the hooks can tear the belt material.

Another serious problem is that before use the hooks can scratch the wearer's skin and cause injury.

WO 2/22061 describes a hook and loop fastening for use on absorbent disposable products, such as pappies. Here the male part of the hook and loop fastening is covered before use by a flap of adhesive tape. However, the primary intention here is not to protect the hooks on the male part of the hook and loop fastening but to use a combination of hook and loop fastening and adhesive tape fastening.

WO 97/28774 describes a combination of adhesive tape and hook and loop fastening for fastening a Happy onto a wearer. According to this publication, it is important that the male part of the hook and loop fastening is protected during storage and before use. The male part is attached at the far end of an attachment flap, which before use is folded over with the hooks protected under the flap. This is provided with an adhesive fastening that holds the attachment flap in the folded position before use and thus prevents the hooks on the hook and loop fastening from hooking fast onto any fibre material before use.

EP 0 262 447 describes a combination of press-studs and hook and loop fastening. This publication describes absorbent products, such as pappies, with an elasticated self-adjusting outer casing, that is an outer casing that flexibly follows the wearer's movements. The press-studs constitute the primary load-bearing fastenings, while the hook and loop fastenings constitute secondary load-bearing fastenings and essentially fill in the spaces between adjacent press-studs, whereby the press-studs together with the hook and loop fastenings form full-length fastenings between, for example, the waist and the leg opening on a nappy.

All the previously known fastenings comprising hook and loop fastenings have the disadvantage that the hooks on the hook and loop fastening are exposed when applying the hook and loop fastening and can accidentally fasten onto other material or scratch the wearer's skin. In spite of the combination of adhesive tape fastening which protects the hooks on the hook and loop fastening during storage, there is to date no completely satisfactory solution.

DISCLOSURE OF INVENTION

By means of the present invention, a mechanical fastening has been achieved which completely eliminates the danger of the hooks fastening accidentally and which, in addition, withstands considerably higher tensile forces when in use in comparison with previously known hook and loop fastenings.

The fastening according to the invention is characterized primarily in that the first part is arranged to be changed manually between a first state and a second state, in that in the first state the hooks are arranged inside a depression in the first part, in that after changing to the said second state the said depression is inverted to a protrusion with the hooks accessible for engagement with the fibres or loops in the second part, in that the hook and loop fastening is locked with the hooks engaged in the fibres or loops in the second part when the first part is changed back from the second state to the first state.

According to an embodiment, the invention is characterized in that in the first state the hooks are arranged to project from a concave surface of a dome or part of a dome, in that this dome or part of a dome is designed to be able to be changed manually between the said first state and second state, and in that in the second state the hooks are arranged to project from a convex surface, in that the hooks are arranged to project radially from the concave surface and from the convex surface respectively, with the hooks converging in a direction outwards from the concave surface and diverging in a direction outwards from the convex surface, in that the hooks on the first part can be inserted between the fibres or into the loops in the second part only when the hooks diverge from the convex surface in the dome's second state, in that the hooks can be manually removed from their engagement with the fibres or the loops only in the said second state, and in that the hooks are locked fast in engagement with the fibres or the loops in the second part when the first part is changed back to the first state after the hooks have been brought into engagement with the fibres or the loops.

An embodiment of the invention is characterized in that the dome is constructed of a rigid material.

According to another embodiment, the invention is characterized in that the dome is designed in such a way that it automatically springs back from the second state to the first state.

According to an embodiment, the invention is characterized in that the first part consists of a bowl-shaped dome with the hooks of the hook and loop fastening arranged on the concave inside of the dome, in that the dome is arranged to be inverted to the said second state by the application of a pressure against the outside of the dome, in which second state the hooks diverge from a convex surface and can be connected to fibres or loops in the second part.

A plurality of further embodiments is apparent from the following patent 1 0 claims.

BRIEF DESCRIPTION OF DRAWINGS

In the following, the invention will be described in greater detail with reference to a number of embodiments that are shown in the attached drawings, in which: Figures 1 a-c show schematically a first embodiment of a fastening according to the invention in different states.

Figures 2 a - c show schematically a second embodiment of a fastening according to the invention in different states.

Figure 3 shows a third embodiment of a fastening according to the invention, which is modified somewhat in relation to the embodiment according to Figure 1.

Figure 4 shows schematically a fourth embodiment of a fastening according to the invention.

Figure 5 shows schematically a fifth embodiment of a fastening according to the invention.

Figure 6a shows schematically a sixth embodiment of a fastening according to the invention.

Figure 6b shows a cross-section along the line b-b in Figure 6a.

Figure 7a shows schematically a seventh embodiment of a fastening according to the invention.

Figure 7b shows a cross-section along the line b-b in Figure 7a.

Figure 8a shows schematically an eighth embodiment of a fastening according to the invention in a first state.

Figure 8b shows the embodiment according to Figure 8a in a second state.

Figure 8c shows a cross-section along the line c-c in Figure fib.

Figure 9 shows schematically a ninth embodiment of a fastening according to the invention.

Figure 10 shows schematically a tenth embodiment of a fastening according to the invention.

Figure 11 shows examples of dimensions that control the force required for changing the fastening according to the first embodiment from a first state to a second state.

Figure 12 shows schematically an example of a thickness gradient for the fastening according to Figure 1.

Figure 13a shows schematically an eleventh embodiment of a fastening according to the invention.

Figure 13b shows a cross-section along the line b-b in Figure 13a.

Figure 14 shows schematically a twelfth embodiment of a fastening according to the invention.

Figure 15 shows schematically a thirteenth embodiment of a fastening according to the invention.

Figures 16 a-e show schematically a number of complex embodiments of the fastening according to the invention.

MODES FOR CARRYING OUT THE INVENTION

Figure 1a shows a first part 1 of a mechanical fastening. This first part 1 has the shape of a segment of a sphere and is permanently attached to a backing material 3 by a base 2. This backing material can be any flexible material, dependent upon the intended area of use of the fastening. The segment of a sphere 1, which is called below a bowl-shaped dome, is made of a relatively rigid material. By relatively rigid is meant here that the material is so rigid that it does not spontaneously change its shape from one three-dimensional shape to another without considerable external force being applied. Hooks 4 are arranged on the inside of the bowl- shaped dome, which hooks, in the state of the dome shown in Figure 1a, extend radially outwards from the concave surface, as shown clearly in the enlarged section of the dome. The hooks thus converge in the state shown in Figure 1a and form at their outer edge, that is radially innemmost, a relatively dense surface, that is with the outer ends of the hooks close together. The "density" of this inner concave surface at the outer end of the hooks depends primarily on the length of the hooks, the number of hooks per unit of surface area and the curvature of the bowl- shaped dome. This "density" can be tailor-made by the choice of the said dimensions in relation to the size of the loops or fibres in the second part of the hook and loop fastening, so that in the state shown in Figure 1a the hooks cannot penetrate into the second part, the female part, of the hook and loop fastening, that is the hooks are too dense to be able to penetrate down into the loops or between the fibres in the female part.

In Figure 1a the second part, the female part of the hook and loop fastening, has been given the reference numeral 5. This can consist of a woven material with loops or of a non-woven fibre material. In the state shown in Figure 1a there is no danger of the male and female parts of the hook and loop fastening being able to be fastened together accidentally. This is prevented by the fact that the hooks are protected inside the concave bowl- shaped part and do not come into contact with the loops or fibres of the female part 5. In addition, as mentioned above, the connection can be prevented by the first and the second part being tailor-made in such a way that the hooks on the male part cannot penetrate between the loops or fibres in the female part 5 when the male part is in the state shown in Figure 1a, that is even if the male and female parts should accidentally come into contact with each other.

By means of the application of a pressure To exerted by the user's thumb, the first part 1 can be inverted into a second state shown in Figure 1b. When the bowl-shaped dome 1 is inverted into the second state, the hooks diverge radially outwards from a now convex surface of the dome, as is shown clearly by the enlarged section shown in Figure 1b. In the first part's second state, the hooks are a greater distance apart than in the first state and are dimensioned to be able to hook fast in loops or between fibres in the second part 5 of the hook and loop fastening. In order to hook the male part to the female part a counter pressure T2 is arranged, as shown by Figure 1b, in association with the inversion of the bowl-shaped dome from the first state to the second state.

In Figure 1 c the bowl-shaped dome has been changed back from the second state shown in Figure 1 b to the first state by means of a pressure T3, taking the second part, the female part 5, with it. In the state shown in Figure 1c, the hooks 4 again converge radially out from the convex inside of the dome. This is illustrated in Figure 1c in the enlarged section of the dome, in which section the loops or fibres in the second part are only indicated schematically. When the male part and the female part are in the joined state shown in Figure 1c, the female part's loops or fibres are held fast by the converging hooks. The hook and loop fastening according to the embodiment shown in Figure 1c thus forms a considerably stronger fastening than that provided by a conventional flat hook and loop fastening provided with corresponding hooks and loops or fibres.

When a closed hook and loop fastening, such as the one in Figure 1c, is to be opened in order to separate the male part and the female part, the dome- shaped first part is depressed by applying a pressure to change the dome from the first state shown in Figure 1c to the second state shown in Figure 1b, in which second state the female part can be separated easily from the male part without any considerable tensile force needing to be used. The size of the separating force that is required depends, of course, upon the material involved and upon the design of the hooks on the male part and of the loops or fibres in the female part.

With a hook and loop fastening according to the embodiment of the invention shown in Figures 1a-c, several considerable advantages are thus obtained in comparison with conventional flat hook and loop fastenings. One advantage is that the hooks are prevented from accidentally hooking onto the female part or onto any other material and another advantage is that the fastening of the joined hook and loop fastening is considerably stronger. As the fastening with converging hooks is considerably stronger than a corresponding flat hook and loop fastening, the number of hooks per unit area of surface on the first part 1 can be less than on a conventional hook and loop fastening for the same purpose.

Another considerable advantage is that even a strong fastening can be designed so that it can be opened with a small tensile force after the first part has been changed from the first state to the second state.

Hook and loop fastenings are currently often used on absorbent disposable products, such as pappies. For use on a small baby it is, of course, an advantage if the hook and loop fastening can be opened without the use of a large tensile force and, in particular, relatively quietly. Conventional hook and loop fastenings can make a noise when they open and can wake a sleeping baby, while a hook and loop fastening according to the invention, for example of the type that is shown in Figure 1, can be designed in such a way that it can be opened essentially silently.

With a design of hook and loop fastening according to the present invention, for example of the type that is illustrated in Figure 1, the possible area of use is also increased in comparison with conventional hook and loop fastenings.

As the fastening between the male part and the female part can be made very strong, hook and loop fastenings according to the invention can be used as fastenings for load straps for heavy lifting devices.

Figures 2a-c show an embodiment that is modified in relation to the embodiment according to Figure 1. The parts corresponding to similar components in the figures have been given the same reference numerals.

The essential difference from the embodiment according to Figure 1 is that the hooks 4 are not placed on the inside of a bowl-shaped dome, but inside a depression 10 on the outside of the dome.

Figure 2a shows the first part in its first and passive state with the hooks 4 protected inside the depression and converging in an outwards direction.

Only when the depression 10 has been changed to the second state shown in Figure 2b by the application of a pressure T. can the hooks 4 that are now diverging outwards be made to engage with the loops or fibres in the female part 5. The first part, the male part with the hooks, is locked fast to the loops or fibres in the female part when the depression is formed again by means of a pressure T2 as shown in Figure 2c.

Above, in both the embodiment according to Figure 1 and in the embodiment according to Figure 2, it has been stated that the first part, the male part, is changed from the second state, that is the state that is shown in Figures 1b and 2b respectively, to the locked state according to Figure 1c and 2c respectively, by means of a pressure. However, the male part can be designed with built-in stresses so that the male part automatically springs back to the first state when the pressure T' ceases. This springing back can, for example, be achieved by variations in thickness of the dome or by localized stiffening.

The dome-shaped first part can also be designed so that a distinct clicking sound is heard when there is a change from one state to the other. This can be used as a safety measure so that it is possible to hear when the hook and loop fastening is opened or closed.

In the embodiments shown in Figures 1 and 2, the first part 1 has been attached by its base 2 around a hole in the backing material 3 on the outside of this. Alternatively, the base 2 of the first part can, of course, be attached around the hole on the opposite side of the backing material, the inside.

In the embodiment shown in Figure 3, the first part 1 consists of a concave dome with hooks 4 arranged on the inside of the dome converging in a radial direction when the first part 1 is in the first state. The concave dome is attached by a straight base 2 to one end of the backing material 3. The female part of the hook and loop fastening, which has loops or fibres that interact with the hooks, has been given the reference numeral 5. The first part 1 is shown in Figure 3 in its first state and not fastened to the second part 5. The first part is manually inverted completely or partially from its first state by means of a pressure T. into the second state, in which the hooks 4 diverge from the inverted and now convex inside of the first part. In the second state, the hooks 4 are brought into engagement with the loops or fibres in the second part 5 when this part is affected by a counter-pressure to the pressure T.. The male and female parts of the hook and loop fastening are thereafter locked in engagement when the first part 1 returns to its first state, which can be carried out automatically if the first part is designed in such a way that it is changed from its first state to the second state by spring action stresses. This springing action can be achieved by means of an inbuilt sprung element (not shown) that is stretched when the first part is changed from the first state to the second. The springing action can also be achieved by built-in material stiffening or by variations in the thickness of the dome.

Altematively, the first part can be changed back manually from the second state to the first state by means of a pressure.

In the embodiments described above, the outline of the first part is circular.

Other shapes for the outline of the dome and other aspects of the design can be varied.

Figure 4 shows an embodiment where the first part has an outline that is oval. The first part has a base 2 which is attached to a backing material around a hole constructed in this (not shown here) in the same way as I described above. The embodiment according to Figure 4a is the same as the embodiment according to Figure 1 apart from the fact that the basic shape is elongated. With this shape, after fastening to a looped or fibre material, different gripping forces are obtained with regard to shearing in different directions. The grip with regard to shearing forces is strongest in the longitudinal direction of the first part.

Figure 5 shows a somewhat modified embodiment. The first part is an elongated shape but, unlike the embodiment according to Figure 4, is asymmetricalwith a blunt end and a pointed end. The force required to invert the bowl-shaped dome is different in the embodiments shown in Figures 4 and 5. In addition, the gripping forces in different directions are different for these two embodiments. It can easily be seen that gripping forces and inverting forces can be varied by the choice of the shape of the first part.

Figure 6a and Figure 6b show an embodiment that is somewhat modified in relation to the embodiment in Figure 4. A defined pressure zone 11 is arranged centrally on the dome. This can be marked, for example by means of a different colour, and is more responsive to pressure in comparison with the rest of the dome. The arrangement with the pressure zone facilitates the inversion from the first state to the second and vice versa. In the embodiment shown, the pressure zone 11 is flat, as shown in Figure fib. Altematively, the pressure zone does not need to be flat, but can have a different curvature to the rest of the dome. In addition to being flat, the pressure zone can have a convex pressure surface or a concave pressure surface. Irrespective of the curvature, the pressure zone can have a thinner material thickness than the rest of the dome. The density can also be different in the pressure zone in comparison with the rest of the dome.

Figure 7 shows an embodiment that is somewhat modified in relation to the embodiment according to Figure 5. Here the oval outline is asymmetrical.

Like the embodiment according to Figure 6, this embodiment has a defined pressure zone 11. The pressure zone 11 is here placed asymmetrically and is closer to the blunt end of the first part 1 and is not flat but consists of a depression.

In the embodiments shown in Figures 6 and 7, the first part is convexly curved, apart from the pressure zone. The first part 1 can also be the shape of the frustum of a cone (not shown).

The mechanical characteristics of the first part 1 can be controlled by variations in shape, material thickness and density over the extent of the first part. By means of its raised shape, the first part has a built- in stress, which counteracts depression. This stress is controlled by the choice of material, curvature of the first part, the rigidity of the base 2 and its fixing.

Other ways of controlling the mechanical characteristics of the first part are to provide the dome of the first part 1 with slits 12 and stiffening 13, as shown in the embodiment according to Figures 8a-8c. In Figure 8a the dome with slits is shown in its initial position, that is before depression. Figure 8b shows the same view with the dome depressed. The depressed dome is shown in cross-section in Figure 8c.

In the embodiment shown, the slits 12 are curved. The slits can be any other shape, for example straight. By selecting different shapes, lengths and numbers of slits, additional ways are obtained of varying the resistance to depression and subsequent springing back to the initial position. By combining slits in the dome and stiffening of the dome, the mechanical I characteristics of the first part can be adjusted. The arrangement of slits, possibly in combination with stiffening, makes it possible to increase the curvature of the first part, which means that the hooks are better protected inside the curvature and the protection against the hooks accidentally fastening onto other material is increased.

Figure 9 shows a further example of varying the mechanical characteristics of the first part. The dome according to Figure 9 is convex and is shown in Figure 9 from the side from which the pressure for depression is applied. The first part's hooks are on the inside of the dome and are not shown. The dome according to Figure 9 is provided with a number of through holes 14. By varying the number of holes, the size of the holes and their location, the mechanical characteristics of the dome can be varied. The arrangement of holes 14 means that the dome is permeable to air, which is advantageous for certain applications. The first part 1 according to Figure 9 can be attached around a peripheral edge of a backing material, as described in the embodiments according to Figures 1-7. Alternatively, the first part according to Figure 9 can constitute the whole product shape. For example, a required three- dimensional sanitary towel or the like can be created.

Figure 10 shows a first part 1 in the form of a meshwork dome. The dome has a base 2 for attachment to a backing material (not shown). The mesh consists of filaments of plastic with selected rigidity and elasticity characteristics. In the embodiment shown, the meshwork dome is asymmetrical with a pointed end and a blunt end. The depression zone 11 is offset towards the blunt end. The mechanical characteristics of the meshwork dome can be controlled by the choice of material, filament thickness, mesh structure, curvature and shape of the curved part and by the extent of the pressure zone.

Figure 11 illustrates the stresses for a segment of a sphere. The radius of I this is indicated by r and the length of the arc over the surface of the segment of the sphere shown is indicated by L. The force required for depression of the convex segment of the sphere is indicated by F and is proportional to L/r.

The force for springing back the depressed segment of the sphere is indicated by f. The force ratio for inversion or springing back is suitably: f/F = 0.5to 1.

Figure 12 shows an example of how the thickness of the dome can vary from i the peripheral base towards the middle of a first part in the shape of a segment of a sphere. By means of the choice of gradient for the thickness, the mechanical characteristics of the first part can be varied. In a corresponding way, it is possible to have a density gradient from the peripheral base towards the centre of the segment of the sphere, whereby the resistance to depression and subsequent springing back can be controlled.

Figures 13a and 13b show an embodiment of the first part 1. This is principally convex, but the height decreases in steps from the top of the convex first part towards the peripheral base. In Figure 13a, the first part has a circular outline, but the stepped structure can have an oval outline or essentially any outline and accompanying stepped threedinensional structure. The mechanical characteristics can be varied in many different ways. It is possible to combine different materials, for example by having different materials in different parts of the structureor laminates of different materials over only certain parts of the stepped structure. The mechanical characteristics can also be controlled by means of the width and/or height of the steps.

In the embodiment according to Figure 14, the first part consists of a central area 15 and four petals 16 projecting from this, which petals are either constructed in one piece with the central area or are attached to it. The petals and the central area can, for example, be cut out of a bowl-shaped flexible but relatively rigid blank. In an unstressed state, the petals 16 are curved and support the central area 15. The hooks on the hook and loop fastening are arranged on the inside of the central area. The central area consists of a plate or is a domed shape.

The petals 16 are flexibly sprung and when the central area is depressed in order to bring the hooks into engagement with the female part of the hook and loop fastening in the form of a looped material or a fibre material, the stresses in the petals 16 increase and when the pressure on the central area ceases, the petals spring back and bring with them the central area together with an area of the hook and loop fastening's female part, which is now in engagement with the hooks on the underside of the central area. In the embodiment shown, the different petals 16 are different shapes and lengths.

Alternatively, the petals can be identical and can be arranged symmetrically around the central area. In an embodiment according to Figure 15, the curvature of the first part as a whole can be increased in comparison with a complete bowl in the same material and thickness. The arrangement of slits or cut-outs 17 in a bowl-shaped blank means that the resistance to depression of the central area is reduced in comparison with a bowl shape without slits and petals.

In an embodiment according to Figure 14, the hooks can thus be well protected against accidental contact with material that the hooks could otherwise fasten onto.

Figure 15 shows an embodiment that is somewhat modified in relation to the embodiment according to Figure 14. Also here the first part consists of four petals 16 projecting from a central area 15. In the embodiment according to Figure 15, there is a flexible support ring 18. This is connected to the four petals 16 and counteracts the depression of a first part which is curved as a whole, as the flexible support ring must be stretched for depression of the central area against the action of the sprung petals 16 and the support ring 18.

In the embodiment according to Figure 15, the first part can be designed as a bowl-shaped blank, with a flexible support ring attached in an unstressed state over the four petals. Alternatively the first part can be designed as an initially flat blank, from which petals 16 are cut out. A flexible ring is thereafter arranged in a stretched state over the four petals, whereby, when it returns from a stretched state, the flexible ring raises the petals 16 and lifts up the central area.

It is, of course, also possible to have a combination of the two different methods of construction, so that a stretched flexible support ring is arranged over the petals cut out of a bowl-shaped blank, whereby these are raised somewhat further when the support ring is released from its stretched state.

Figure 16a shows three separate and interacting partial areas 101, 102, 103, which together form the male part of a hook and loop fastening. In Figure 16, the backing material for the male part and the female part has been omitted.

The partial areas 101, 102, 103 that are shown only schematically can be of the type that was described in connection with Figure 1. With this embodiment, a secure fastening can be achieved along a straight line.

Figure 16b shows two partial areas 101, 102 of the same kind as the partial areas in Figure 1 6a in combination with an oval partial area of the type that is shown in Figure 4. This embodiment can be suitable for withstanding forces in two different directions.

Figure 16c shows an embodiment in the form of two circular partial areas 101, 102 separated by an interjacent oval partial area 104, whereby an elongated male part of a hook and loop fastening is achieved.

Figure 16d shows a combination of two oval partial areas 104 arranged with their longitudinal directions at an acute angle in relation to each other.

Figure 16e shows a very complex variant with three partial areas of the type that was shown in Figure 16a in combination with an oval partial area 104 and a more elongated additional oval partial area 105, whereby a male part of a hook and loop fastening is achieved that is designed to withstand stresses in three different directions, in the longitudinal direction of the interacting partial areas 101, 102, 103, in the longitudinal direction of the oval partial area 104 and in the longitudinal direction of the elongated oval partial area 105.

An example of a suitable material for the first part in all the embodiments described above is polyethylene. Other examples of material for the first part, that is the male part of a hook and loop fastening, are described in EP 0 491 347 B1 and in EP 0 324 578 B1.

The invention is not restricted to the embodiments described above, but a plurality of modifications is possible within the framework of the following patent claims.

For example, the first part can consist of two or more layers of the same or different materials. When there are several layers of material, these can be completely overlapping each other and can be laminated. Altematively, one or more layers of material can extend over only partial areas of the first part and can be combined with other incorporated layers of material.

Claims (22)

1. Mechanical fastening, which fastening comprises a first part (1) which is provided with hooks (4), and a second part (5) which has fibres or loops that interact with the hooks to form a hook and loop fastening, characterized in that the first part (1) is arranged to be able to be changed manually between a first state and a second state, in that in the first state the hooks (4) are arranged inside a depression in the first part, in that after changing to the said second state the said depression is inverted to a protrusion with the hooks (4) accessible for engagement with the fibres or loops in the second part (5), in that the hook and loop fastening is locked with the hooks (4) engaged in the fibres or loops in the second part when the first part is changed back from the second state to the first state.

2. Mechanical fastening according to Claim 1, characterized in that in the first state the hooks (4) are arranged to project from a concave surface of a dome or part of a dome, in that this dome or part of a dome is designed to be able to be changed manually between the said first state and second state, and in that in the second state the hooks (4) are arranged to project from a convex surface, in that the hooks (4) are arranged to project radially from the concave surface and from the convex surface respectively, with the hooks (4) converging in a direction outwards from the concave surface and diverging in a direction outwards from the convex surface, in that the hooks (4) on the first part (1) can be inserted between the fibres or into the loops in the second part (5) only when the hooks diverge from the convex surface in the dome's second state, in that the hooks (4) can be manually removed from their engagement with the fibres or the loops only in the said second state, and in that the hooks (4) are locked fast in engagement with the fibres or the loops in the second part (5) when the first part is changed back to the first state after the hooks have been brought into engagement with the fibres or the loops.

3. Mechanical fastening according to Claim 1 or 2, characterized in that the dome is constructed of a rigid material.

4. Mechanical fastening according to any one of the preceding claims, characterized in that the dome is designed in such a way that it automatically springs back from the second state to the first state.

5. Mechanical fastening according to any one of the preceding claims, characterized in that the first part (1) consists of a curved bowl shaped dome with the hooks (4) on the hook and loop fastening arranged on the concave inside of the dome, in that the dome is arranged to be inverted to the said second state by the application of a pressure against the outside of the dome, in which second state the hooks (4) diverge from a convex surface and can be connected to fibres or loops in the second part (5).

6. Mechanical fastening according to any one of Claims 1-4, characterized in that the first part (1) consists of a bowl-shaped dome with the hooks (4) on the hook and loop fastening arranged in a concave depression (10) on the outside of the dome, in that the depression (10) is arranged to be pressed out from its first state to the second state, in which the hooks (4) diverge from a convex surface and can be connected to fibres or loops in the second part (5).

7. Mechanical fastening according to any one of the preceding claims, characterized in that the first part (1) is made of a material and is designed in such a way that the change from the first state to the second and vice versa is accompanied by a distinct clicking sound.

8. Mechanical fastening according to Claim 4, characterized in that the dome is designed with built-in stresses which are arranged to counteract changing of the first part (1) from the first state to the second state and which after the said change are arranged to spring the first part (1) back to the first state.

9. Mechanical fastening according to Claim 8, characterized in that the said stresses are achieved by means of the choice of the shape of the first part.

10. Mechanical fastening according to Claim 8 or 9, characterized in that the said stresses are achieved by means of the choice of different density and/or thickness in different areas of the first part (1).

11. Mechanical fastening according to any one of the preceding claims, characterized in that the first part has an outer edge (2) which serves as a base and is designed for permanent attachment to a backing material 1 5 (3).

12. Mechanical fastening according to any one of the preceding claims, characterized in that the first part (1) has an elongated shape.

13. Mechanical fastening according to any one of the preceding claims, characterized in that the first part has localized stiffening (13) to control the changing of the first part (1) from the first state to the second and vice versa.

14. Mechanical fastening according to any one of the preceding claims, characterized in that the first part consists of a number of separate interacting partial areas (101, 102, 103, 104, 105) with the same or different shapes (Figure 16).

15. Mechanical fastening according to any one of the preceding claims, characterized in that the mechanical fastening consists in its entirety of a number of hook and loop fastenings (Figure 16) which are arranged to enable the fastening to withstand shearing forces in a plurality of directions.

16. Mechanical fastening according to Claim 15, characterized in that lines of action of the hook and loop fastening for withstanding forces in the said directions is achieved by means of elongated first parts arranged with their longitudinal directions along the said directions and/or by means of a number of symmetrical first parts arranged in a line along one or more of the said directions (Figure 16). 3

17. Mechanical fastening according to any one of the preceding claims and intended to be used in absorbent disposable products, such as 3 pappies, sanitary towels, panty liners or incontinence pads, characterized in that the first part (1) of at least one hook and loop fastening comprised in the fastening is designed also to create the required three-dimensional shape of the absorbent disposable product, which shape can be intended to create a raised mound on the absorbent disposable product facing towards the user's genitalia.

18. Mechanical fastening according to any one of the preceding claims, characterized in that said first part or parts (1) are constructed of a meshwork dome with the required rigidity.

19. Mechanical fastening according to any one of the preceding claims, characterized in that the said first part (1) is corrugated (Figure 13).

20. Mechanical fastening according to any one of the preceding claims, characterized in that the first part (1) or the first parts are made of a plastic with suitable rigidity characteristics.

21. Mechanical fastening according to any one of Claims 1-19, characterized in that the first part (1) is made of a fibre material which has - 24 been given suitable rigidity characteristics and the required shape by means of treatment with heat and pressure at a suitable moisture content and/or by treatment with some agent, such as an adhesive, which binds the fibre material into the created three-dimensional shape with the required rigidity.

22. Mechanical fastening according to claim 1 substantially as described herein with reference to any one of Figures 1 to 16.