Field of the Invention

The present invention relates to an attachment arrangement which is configured to provide for releasable attachment of an object, such as a personal electronic device, to a surface. Background Art

Temporary attachment of personal electronic devices such as mobile telephones, tablet computers and game consoles to surfaces in the home, office or elsewhere can provide for their ease and convenience of use. For example one may wish to attach a mobile telephone temporarily at a convenient location and height in the home, such as in the kitchen, and at another time to attach the mobile telephone temporarily at a convenient location in the office clear of one's desk but within reach, such to the side of a cabinet or to the wall. Mindful of the utility of a means of temporarily attaching personal electronic devices in this fashion, the present inventors investigated diverse approaches to providing for temporary attachment before devising the present invention. It is therefore an object for the present invention to provide an attachment arrangement which is configured to provide for releasable attachment of an object, such as a personal electronic device, to a surface.

Statement of Invention

According to a first aspect of the present invention there is provided an attachment arrangement which is configured to provide for releasable attachment of an object, such as a personal electronic device, to a surface, the attachment arrangement comprising a unitary body, the unitary body being planar and having a laminar structure, the unitary body comprising: a first layer comprising an adhesive; and a second layer comprising particulate rare-earth magnetic material.

The attachment arrangement comprises a unitary body. The unitary body is planar and has a laminar structure. A first layer of the unitary body comprises an adhesive. A second layer of the unitary body comprises particulate rare-earth magnetic material. The attachment arrangement may be brought into use by bringing the first layer into contact with a surface of an object, for example a rear surface of a personal electronic device such as a mobile telephone, whereby the adhesive comprised in the first layer provides for adhesion of the unitary body to the object. Then the object may be releasably attached to a surface, for example a surface in a room and more specifically a ferromagnetic surface such as may constitute an exterior surface of a fridge, by placing the object against the surface such that the second layer is presented to the surface. The magnetic field produced by the particulate rare-earth magnetic material comprised in the second layer provides for releasable attachment of the unitary body and hence the object to the surface. The particulate rare-earth magnetic material comprised in the second layer may therefore be magnetised whereby the unitary body is operative as a permanent magnet.

The present inventors became appreciative of the merit in providing an attachment arrangement that does not change a form factor of an object, such as a personal electronic device, require undue modification of a housing of the object, such as of a case of a personal electronic device, or compromise the aesthetic appeal of the object. Amongst other things, adhesive gel pads were investigated. The adhesive gel pads were demonstrated to work but were found to be of limited lifetime on account of accumulated dirt compromising the operation of the gel pads. Hook and loop arrangements were also investigated. The hook and loop arrangements were demonstrated to work but were found to be of limited lifetime on account of fluff collecting on the hook and loop members which compromised their proper mechanical engagement.

Composite magnetic materials such as ferrite were investigated. Such materials were not liable to the fouling suffered by the above described adhesive gel pads and hook and loop arrangements. The holding force of a magnetic material is a function of the area of magnetic material presented to the surface to which the object is to be attached presented and also the thickness of the magnetic material, amongst other things. Objects to be attached to a surface of particular but not exclusive interest to the inventors comprise personal electronic devices such as smart phones and tablet computers. The attachment arrangement may therefore be configured to provide for releasable attachment of a personal electronic device to a surface.

Smart phones and tablet computers typically have a weight in the range of 100 g to 700 g. The length and width of the rear surface of such devices is typically in the range of 15 mm x 50 mm to 200 mm x 250 mm. Bearing in mind the desire not to change a form factor or compromise the aesthetic appeal of the device, an attachment arrangement should not cover an undue amount of the surface of the device to be presented to the surface and should preferably not extend too close to or beyond an edge of the device. A modest area of unitary body relative to the area of the surface of the device to which the unitary body is to be adhered may therefore be desirable. Also an attachment arrangement should provide for close proximity of the device to the surface to which the device is attached. The attachment arrangement should therefore be relatively thin. Area and thickness limitations impose a limit on the weight that can be supported by the magnetic material. It was found that composite magnetic materials were incompatible with device area and proximity requirements and weight bearing requirements. For example a layer comprising ferrite of appropriate thickness and weight bearing capability was found be of an undesirably large area. Bearing the dimensions of rear surfaces of personal electronic devices and their weight in mind, magnetic material having a maximum energy product, BH _max , of at least 30 MGOe was found to be desirable. On the other hand, magnetic material having a maximum energy product, BH _max , of more than 48 MGOe was found to provide for too great an attachment force such that detachment of the device from the surface was unduly difficult. Furthermore, magnetic material having a maximum energy product, BH _max , of more than 48 MGOe was liable to compromise proper operation of electronic circuits comprised in the device. The magnetic material may therefore have a maximum energy product, BH _max , of 30 MGOe and greater but of 48 MGOe and less. More specifically the magnetic material may have a maximum energy product, BH _max , of 33, 35, 38, 40, 42 or 45 MGOe and greater. Alternatively or in addition the magnetic material may have a maximum energy product, BH _max , of 45, 42, 40, 38, 35, or 33 MGOe and less. Under certain circumstances a maximum energy product, BH _max , of between 34 and 36 MGOe was found to provide an appropriate level of attachment force.

The rare-earth magnetic material may comprise neodymium alloy, i.e. Nd ₂ Fe-i ₄ B. Neodymium alloy was found to provide an appropriate level of maximum energy product amongst other things. The neodymium alloy may be at least one of N30, N35, N38, N40, N42, N45 and N48 grade. More specifically the neodymium alloy may be N35 grade.

The second layer may comprise at least 2.5 g, 3.5 g, 4.5 g, 5 g, 5.5 g, 6 g, 6.5 g, 7 g, 7.5 g, 8 g, 9 g, 10 g, or 1 1 g of neodymium alloy. The second layer may comprise no more than 12 g, 10 g, 9 g, 8 g, 7.5 g, 7 g, 6.5 g, 6 g, 5.5 g, 5 g, 4.5 g or 3.5 g of neodymium alloy. Under certain circumstances an attachment force provided by the unitary body has been found to increase markedly between 5 g and 7.5 g weight of neodymium alloy. The second layer may therefore comprise a weight of neodymium alloy of at least 5 g, 6 g or 7 g. Under certain circumstances an attachment force provided by the unitary body has been found to increase more gradually above 7.5 g weight of neodymium alloy. A greater weight of neodymium alloy may be

undesirable on account of the weight of the attachment arrangement increasing to a less manageable level. The second layer may therefore comprise a weight of neodymium alloy of no more than 10 g, 9 g or 8 g. More specifically the second layer may comprise a weight of neodymium alloy of 7.5 g. As mentioned above the magnetic material is of particulate form. The second layer may be formed such that particles of magnetic material are dispersed over the surface of the second layer and perhaps through the second layer. The second layer may further comprise a polymer, such as Poly(methyl acrylate) (PMA), and more specifically a polymer composite, such as comprises carbon black, or a metal such as stainless steel. The second layer may lend rigidity to the unitary body. On account of the thinness of the unitary body compared with its length and width, the unitary body may be capable of being flexed to a modest extent. Nevertheless the unitary body may not be pliable to the extent of a body formed from the like of textile sheet material.

The second layer may abut against the first layer. The first layer may have a thickness of between 0.025 mm and 0.075 mm and more specifically of 0.05 mm. The second layer may have a thickness of between 0.25 mm and 0.75 mm and more specifically of 0.5 mm.

The unitary body may comprise a third layer. The third layer may comprise a plastics material such as a polymeric material. Furthermore the third layer may comprise polyester, for example, spandex polyester material such as adhesive spandex polyester material. The third layer may have a thickness of between 0.025 mm and 0.075 mm and more specifically of 0.05 mm. A design, such as a logo, and the like of product information may be printed on the third layer. The third layer may abut against the second layer. The unitary body may comprise a fourth layer. The fourth layer may be transparent or translucent. The fourth layer may comprise a plastics material such as a polymeric material. Furthermore the fourth layer may comprise polyester, for example, spandex polyester material such as adhesive spandex polyester material. The fourth layer may have a thickness of between 0.0125 mm and 0.0375 mm and more specifically of 0.025 mm. The outer edges of the unitary body may define substantially a rectangle and perhaps a square. Corners of the unitary body may be rounded to provide for aesthetic appeal. According to a first embodiment, the unitary body may not define an aperture therethrough. The unitary body may be of substantially a same thickness as one progresses across the entire surface of the unitary body. A unitary body according to the first embodiment may be appropriate for a smaller object such as a smart phone where the object is a personal electronic device. The unitary body may have a length of at least 30 mm, 40 mm or 50 mm. The unitary body may have a length of no more than 60 mm, 50 mm or 40 mm. In one form the unitary body may have a length of 45 mm. The unitary body may have a width of at least 30 mm, 40 mm or 50 mm. The unitary body may have a width of no more than 60 mm, 50 mm or 40 mm. In one form the unitary body may have a width of 45 mm.

According to a second embodiment the unitary body may define an aperture therethrough. The aperture may be rectangular and perhaps square. The aperture may be defined such that it is substantially coaxial with a centre of the unitary body when viewed from a side that is presented to the object to be attached. The unitary body may thus define a frame. A unitary body according to the second embodiment may under certain circumstances provide for improved stability of the object when attached, such as where a wider and longer object is attached but without compromising the operation of the object where the object is a personal electronic device. More specifically a personal electronic device having a surface area of more than 60 cm ² has been found to be more stably attached by way of a unitary body according to the second embodiment. A magnetic field supported by a

correspondingly wide and long unitary body according to the first embodiment may interfere with proper operation of electronic circuits comprised in a personal electronic device. Reducing the length and width of a unitary body according to the first embodiment may, however, reduce stability by allowing, for example, for rocking of the attached object. Having a unitary body which defines an aperture

therethrough may mitigate the effect of the electric field on the electronic circuits whilst providing for stability of attachment by way of the frame like structure of the unitary body. A wider and longer frame like structure may permit less rocking of an attached object than a narrower and shorter structure of the same surface area. Irrespective of whether the first or second embodiment is employed, a surface area of the unitary body may be no more than 20% of an area of the surface of the device to which the unitary body is to be attached. The unitary body of the second embodiment may have a length of at least 70 mm, 80 mm, 90 mm or 100 mm. The unitary body may have a length of no more than 1 10 mm, 100 mm, 90 mm or 80 mm. In one form the unitary body may have a length of 95 mm. The unitary body may have a width of at least 70 mm, 80 mm, 90 mm or 100 mm. The unitary body may have a width of no more than 1 10 mm, 100 mm, 90 mm or 80 mm. In one form the unitary body may have a width of 95 mm. The aperture may be of proportionate length and width. For example and where the unitary body is 95 mm square, the aperture may be 45 mm square.

The attachment arrangement may comprise at least one further unitary body. Each of the at least one further unitary body have a laminar structure. More specifically, a first layer of the further unitary body may comprise an adhesive. A second layer of the further unitary body may comprise a ferromagnetic material. The further unitary body may be brought into use by pressing the first layer against a surface to which one wishes to attach an object whereby the second layer of the further unitary body faces away from the surface. The unitary body comprising the magnetic material may have been attached already by way of the first adhesive layer to the object to be attached. The object may then be attached to the further unitary body by placing the body against the surface of the further unitary body. The further unitary body may find use where the surface to which one wishes to attach the object is not defined by ferromagnetic material, such as the surface of a wood based cupboard door, or where the surface is defined by a ferromagnetic material of insufficient magnetic susceptibility to provide for proper attachment of the object.

The further unitary body may be of a form and of dimensions in respect of one or more features described above with reference to the unitary body comprising the magnetic material. For example the further unitary body may be configured in accordance with the first or second embodiment described above with reference to the unitary body comprising the magnetic material. The further unitary body may be of substantially a same length and width as the unitary body comprising the magnetic material.

The attachment arrangement may comprise plural further unitary bodies, such as four further unitary bodies. Each of the plural further unitary bodies may be attached on a relatively permanent basis at different locations whereby the object with the magnetic material comprising unitary body already attached may be attached readily at each of the different locations in turn. For example each of first and second further unitary bodies may be attached at first and second locations in the home, a third further unitary body may be attached to the dashboard of a car and the fourth further unitary body may be attached at a location in the workplace.

Permanent magnetic foils were investigated in respect of the second layer. More specifically permanent magnetic foils comprising strontium ferrite powder and neodymium powder in a plastics polyethylene carrier were investigated. However certain grades of stainless steel were found to offer more superior performance. The second layer of the further unitary body may therefore comprise steel and more specifically stainless steel. The stainless steel may be austenitic. More specifically the stainless steel may be an alloy comprising chromium and nickel. The alloy may further comprise manganese. 101 , 301 and 201 grades of stainless steel were shown to provide progressively better magnetic permeability.

The second layer of the further unitary body may abut against the first layer. The first layer of the further unitary body may have a thickness of between 0.025 mm and 0.075 mm and more specifically of 0.05 mm. The second layer of the further unitary body may have a thickness of between 0.25 mm and 0.75 mm and more specifically of 0.5 mm.

An adhesive layer of a unitary body described above may be covered by a peelable layer. The peelable layer may be in place before the unitary body is brought into use. When someone wishes to bring a unitary body into use, the peelable layer is peeled from the unitary body to expose the adhesive layer and thereby allow for adhesion of the unitary body, for example to the object or to the surface to which the object is to be attached.

According to a further aspect of the present invention there is provided an

attachment arrangement which is configured to provide for releasable attachment of an object to a surface, the attachment arrangement comprising a unitary body having a laminar structure, the unitary body comprising: a first layer comprising an adhesive; and a second layer comprising magnetic material. The unitary body may be planar. Alternatively or in addition, the magnetic material may comprise magnetic material of a permanently magnetic nature. Alternatively or in addition, the magnetic material may comprise rare-earth magnetic material. More specifically, the magnetic material may comprise neodymium alloy. Alternatively or in addition, the magnetic material may comprise particulate magnetic material.

Further embodiments of the further aspect of the present invention may comprise one or more features of a previous aspect of the present invention.

Brief Description of Drawings Further features and advantages of the present invention will become apparent from the following specific description, which is given by way of example only and with reference to the accompanying drawings, in which:

Figure 1 shows a first embodiment of attachment arrangement according to the present invention;

Figure 2 shows a second embodiment of attachment arrangement according to the present invention;

Figure 3A is a cross section through a first unitary body of the attachment arrangement of Figure 1 or 2;

Figure 3B is a cross section through a second unitary body of the attachment arrangement of Figure 1 or 2; and

Figure 4 is a graph of the pull in Newtons against weight of neodymium powder comprised in the first unitary body of the attachment arrangement. Description of Embodiments

A first embodiment of attachment arrangement 10 according to the present invention is shown in Figure 1 . The attachment arrangement 10 of Figure 1 comprises a first unitary body 12 and a second unitary body 14 (which constitutes a further unitary body). Each of the first and second unitary bodies 12, 14 is 45 mm square. Each of the four corners of each of the first and second unitary bodies 12, 14 is rounded and has a radius of curvature of 2 mm. As can be seen from Figure 1 , each of the first and second unitary bodies 12, 14 lacks an aperture in contrast to the second embodiment described below with reference to Figure 2.

Normally the attachment arrangement 10 according to the first embodiment comprises one first unitary body 12 and plural second unitary bodies 14, such as four second unitary bodies 14. The first unitary body 12 is attached on a relatively permanent basis to the rear surface of a smart phone. Each of the plural second unitary bodies 14 is attached on a relatively permanent basis to a surface at a different location. For example, each of first and second further unitary bodies is attached at first and second locations in the home, a third further unitary body is attached to the dashboard of a car and the fourth further unitary body is attached at a location in the workplace. The first unitary body 12 and the second unitary body 14 are configured as described below with reference to Figures 3A and 3B for their releasable attachment to each other whereby the smart phone can be attached temporarily at the location of each of the plural second unitary bodies 14 in turn. A second embodiment of attachment arrangement 20 according to the present invention is shown in Figure 2. The attachment arrangement 20 of Figure 2 comprises a first unitary body 22 and a second unitary body 24 (which constitutes a further unitary body). Each of the first and second unitary bodies 22, 24 is 95 mm square. Each of the four external corners of each of the first and second unitary bodies 22, 24 is rounded and has a radius of curvature of 12.5 mm. As can be seen from Figure 2, each of the first and second unitary bodies 22, 24 defines an aperture 26 which is 45 mm square with rounded corners each having a radius of curvature of 2 mm. In common with the first embodiment of Figure 2 the attachment arrangement 20 of the present embodiment normally comprises one first unitary body 22 and plural second unitary bodies 24, such as four second unitary bodies 24. The first unitary body 12 is attached on a relatively permanent basis to the rear surface of a tablet computer. Each of the plural second unitary bodies 24 is attached on a relatively permanent basis to a surface at a different location. The first unitary body 22 and the second unitary body 24 are configured as described below with reference to Figures 3A and 3B for their releasable attachment to each other whereby the tablet computer can be attached temporarily at the location of each of the plural second unitary bodies 24 in turn. In view of the first and second unitary bodies 12, 14 of the first embodiment having dimensions substantially the same as the apertures of the first and second unitary bodies 22, 24 of the second embodiment, the first unitary bodies 12, 22 of the first and second embodiments are formed by stamping from sheet material and the second unitary bodies 14, 24 of the first and second embodiments are formed by stamping from sheet material.

Figure 3A is a cross section through each of the first unitary bodies 12, 22 of the first and second embodiments of Figures 1 and 2. As can be seen from Figure 3A the first unitary body has a laminar structure. The first unitary body comprises a first layer 42, which defines a first exterior surface of the first unitary body, a second layer 44, which abuts against the first layer 42, a third layer 46, which abuts against the second layer 44, and a fourth layer 48, which abuts against the third layer 46 and defines a second exterior surface of the first unitary body. The first layer 42 comprises an adhesive. More specifically the first layer 42 is 0.05 mm thick 300LSE (9453LE) adhesive transfer tape from 3M. Before the first unitary body is brought into use the first exterior surface defined by the first layer 42 is covered, in

accordance with conventional practice, with a peelable layer which is removed when the first unitary body is being brought into use. The second layer 44 is 0.5 mm thick. The second layer 44 comprises either stainless steel and powdered N35 grade neodymium material which is dispersed in certain forms over and in certain other forms through the stainless steel or a polymer, such as Poly(methyl acrylate) (PMA), through which powdered N35 grade neodymium material is dispersed. 7.5 g of powdered N35 grade neodymium material is comprised in the second layer. The N35 grade neodymium material is from AIC Engineering Limited of 7/F, East Block 203, Terra Industry & Trade Park, Che Gong Miao, Futian, Shenzhen, 518048, China. The second layer 44 is manufactured by G3 s.r.o. of Zborovska 1 , 768 02 Zdounky, Czech Republic. The third layer 46 is formed from adhesive spandex polyester material and is 0.05 mm thick. A design, such as a logo, and the like of product information is printed on the surface of the third layer 46 that is oriented towards the fourth layer 48. The fourth layer 48 is transparent or translucent and is 0.025 mm thick. The fourth layer is formed from adhesive spandex polyester material. The first to fourth layers 42, 44, 46, 48 are joined together to form the structure shown in Figure 3A by a conventional laminating process. The magnetic material comprised in the first unitary body 12, 22 is magnetised in accordance with well known practice. Figure 3B is a cross section through each of the second unitary bodies 14, 24 of the first and second embodiments of Figures 1 and 2. As can be seen from Figure 3B the second unitary body has a laminar structure. The second unitary body comprises a first layer 62, which defines a first exterior surface of the second unitary body and a second layer 64, which abuts against the first layer 62 and defines a second exterior surface of the second unitary body. The first layer 62 comprises an adhesive. More specifically the first layer 42 is 0.05 mm thick 300LSE (9453LE) adhesive transfer tape from 3M. Before the second unitary body is brought into use the first exterior surface defined by the first layer 62 is covered, in accordance with conventional practice, with a peelable layer which is removed when the second unitary body is being brought into use. The second layer 64 is 0.5 mm thick. The second layer 64 comprises grade 101 stainless steel from Kangfeng Group Industry Co. Ltd. of Panling Industrial Zone, Taihe Road, Shipai Town, Dongguan City, Guangdong, China. The first and second layers 62, 64 are joined together to form the structure shown in Figure 3B by a conventional laminating process.

Each of the first and second embodiments is brought into use by attaching on a relatively permanent basis the first unitary body 12, 22 to a respective one of a smart phone and a tablet computer. The first unitary body 12, 22 is attached by pressing the adhesive bearing first exterior surface of the first unitary body 12, 22 against the rear surface of the personal electronic device. Where the personal electronic device is to be attached to a surface defined by ferromagnetic material of sufficient magnetic susceptibility there is no need for the second unitary body 14, 24. The rear surface of the personal electronic device is therefore held against the ferromagnetic material defined surface and the magnetic field supported by the magnetic material in the first unitary body is operative to attach the personal electronic device to the surface. Where it is desired to attach the personal electronic device to a surface which is defined by material of insufficient magnetic susceptibility, one of the second unitary bodies 14, 24 is used. More specifically one of the second unitary bodies 14, 24 is attached on a relatively permanent basis to a surface by way of the adhesive bearing first exterior surface of the second unitary body 14, 24. The rear surface of the personal electronic device is then held against the surface bearing the second unitary body 14, 24 and such that the first and second unitary bodies are aligned, whereby the magnetic field supported by the magnetic material in the first unitary body is operative to attach the personal electronic device to the surface.

The attachment arrangement of the present invention is configured to attach a personal electronic device such as a smart phone or tablet computer to a surface such that the personal electronic device is held in a vertical plane or indeed in horizontal plane. The personal electronic device is so held without minimal movement and without suffering loss of attachment despite vibration such as might arise when the personal electronic device is attached to a location in a car. Figure 4 shows a graph of the weight in grams of N35 neodymium powder comprised in the second layer 44 of the first unitary body 12, 22 against the force in Newtons required to detach the first unitary body 12, 22 from the second unitary body 14, 24. As can be seen, there is a marked increase in force required to detach the first unitary body 12, 22 when more than 5g of N35 neodymium powder is comprised in the second layer 44 of the first unitary body 12, 22. The embodiments of the present invention are configured for at least 1000 cycles of use, i.e. attachment of the unitary member comprising the magnetic material to the further unitary member and detachment therefrom, before there is appreciable loss of force of attachment.