Abstract:
An inflatable cushion including: an inflatable body, having an upper surface and a lower surface, said body including an air-impermeable skin defining a chamber, an elastic foam core within said chamber and a sealable air valve; and an external elastic foam layer substantially covering at least one of said upper and lower of surfaces; wherein: the foam core is formed of a foam having a density of between about 15 kg/m3 and about 35 kg/ma and a hardness of between about 25 newtons and about 45 newtons; and the foam layer is formed of a foam having a density of between about 35 kg/m3 and about 65 kg/m3 and a hardness of between about 35 newtons and about 95 newtons.

Description:
[0001]    This application is the national stage of International Patent Application No. PCT/AU2013/000389 filed on Apr. 11, 2013, which claims priority to Australian Patent Application No. AU 2012901425 filed on Apr. 11, 2012, all of which are hereby incorporated by reference in their entireties as if fully set forth herein. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    The present invention relates to an inflatable cushion and, in particular, a self-inflatable cushion particularly for chiropractic or orthopaedic use. 
         [0004]    The present invention also relates to a mattress including the abovementioned inflatable cushion. 
         [0005]    The present invention further relates to an air valve assembly for use in the abovementioned inflatable cushion. 
         [0006]    2. Related Art 
         [0007]    Cushions, including pillows, are extensively used in domestic, recreational and therapeutic applications. The demand for comfortable cushions is very great and this demand is increasing as the standard of living continues to rise, particularly in Western societies. 
         [0008]    Cushions also have many uses in the healthcare fields, particularly in relation to persons who have chiropractic, orthopaedic or similar complaints. 
         [0009]    As is well understood, typical cushions incorporate an external coating (or skin) which encloses a soft inner core. This inner core is generally formed of feathers, soft foam or other similar materials. 
         [0010]    Inflatable cushions have also been developed. Such cushions generally consist of an inflatable bladder, an internal chamber, and a sealable air valve for enabling air to enter (and exit from) the chamber. In these products, air is typically blown or pumped into the chamber, via the air valve, by the user. Such products have become popular in camping applications because of their light weight, ability to be deflated into a small volume, and their ease of use. 
         [0011]    Such products also have been used in chiropractic and orthopaedic fields. For instance, U.S. Pat. No. 6,047,025, in the name of Adnan Khazaal, discloses an ‘orthopaedic pillow’ which incorporates a hollow inflatable bladder which is able to be inflated by means of a hand pump. 
         [0012]    Similarly, U.S. Pat. No. 6,327,725, describes a ‘pillow with adjustable neck support’ which includes a foam pillow having ‘an inflatable airtight chamber . . . for providing adjustable support to the user&#39;s neck’. The hollow chamber is adapted to be inflated by a manual hand pump. 
         [0013]    Another U.S. Pat. No. 4,829,614, discloses a pillow having an adjustable neck support which includes a number of separately inflatable hollow chambers within the pillow. 
         [0014]    A further U.S. Pat. No. 6,397,415, discloses an ‘orthopaedic pillow’ having an inflatable hollow air chamber and a separate water chamber. 
         [0015]    A benefit of inflatable cushions is that they can, generally, be inflated to any desired level according to the requirements or desires of a user. For instance, if a firmer cushion is desired, it can be inflated up to (or near) its full capacity. If, however, a softer cushion is desired, it may only need to be partially inflated. This can be particularly advantageous in the fields of chiropracty and orthopaedics where it is beneficial to be able to select and alter the degree of firmness/softness of a cushion for use with a patient. 
         [0016]    In more recent times, self-inflatable products (such as mattresses and cushions) have been developed. These products typically consist of an inflatable bladder, an internal chamber with a compressible foam substance within the chamber, and an air valve. When not in use, air is expelled from the product and the foam within the internal chamber is compressed and the air valve is sealed shut. When the product is to be used (e.g. as a mattress), the air valve is opened, enabling air to enter into the chamber. This then enables the foam substance to expand to its natural expanded state. As the foam expands, this causes further air to enter into the internal chamber, thereby causing the product to self inflate. Such a product is disclosed in U.S. Pat. No. 6,016,582 in the name of Lynn D. Larson. 
         [0017]    A problem associated with existing inflatable cushions (including pillows) is that they tend to exhibit a bouncy feel when in use. For instance, when fully inflated, the cushion is hard and uncomfortable to lie on. When under-inflated, the cushion tends to provide inadequate support. Somewhere in-between the fully inflated and the under-inflated states, there may be a state which is reasonably comfortable for a user. However, it is time-consuming and awkward for a user to try and identify this state as it involves manually opening the valve (typically by rotating a rotatable cap), expelling air or blowing air in, re-trying the cushion (for comfort) and if not comfortable, repeating the process (perhaps several times). 
         [0018]    Also, inflatable cushions tend not to provide any resistance—and therefore no real support—against any sideways or rotational movement of the head (or other part of the body). Accordingly, such inflatable cushions can be rather uncomfortable. Also, and for similar reasons, such inflatable cushions may be disadvantageous to persons suffering orthopaedic or chiropractic problems. 
         [0019]    In the fields of chiropractic and orthopaedic treatments, it is desirable to have cushions which do provide adequate support to a user&#39;s head (or other body part). It is further desirable to have a cushion which is adapted to vary in firmness depending on the size of the user, the user&#39;s particular condition, or the degree of firmness of the cushion which is desired by the user. Alternatively, quite a wide range of cushions, of different sizes and/or differing firmness, need to be produced to satisfy the various needs of different users or the same user at different times. None of the products described above satisfy these criteria. 
       SUMMARY 
       [0020]    Accordingly, one aspect of the present invention is directed to an inflatable cushion which at least ameliorates some of the problems and/or deficiencies of some of the existing products described above. In particular, this aspect of the present invention is directed to an improved self-inflatable cushion which is adapted to vary in firmness according to a user&#39;s requirements. 
         [0021]    Another aspect of the present invention is directed to a mattress comprising (as part of the mattress) an inflatable cushion according to the first aspect of the invention, whereby the firmness of a portion of the mattress is able to be varied according to a user&#39;s requirements. 
         [0022]    As noted above, self-inflatable products (such as mattresses and cushions) incorporate air valves to enable air to be selectively inserted into, or expelled from, the relevant product. 
         [0023]    Typically, such air valves generally include a rotatable cylindrical outer wall which is adapted to rotate between a valve-open position and a valve-closed position (and vice versa). In order to enable air to enter through the air valve, the cylindrical outer wall is positioned in its valve-open position. Once the desired amount of air has been inserted into the inflatable product, the cylindrical outer wall is manually rotated in one direction to its valve-closed position. Similarly, when the air valve needs to be re-opened (e.g. to allow air to be expelled from the product) the cylindrical outer wall is manually rotated in the opposite direction to a valve-open position. 
         [0024]    Although such air valves work reasonably well, the manual rotation of the cylindrical outer wall between the valve-open and the valve-closed positions can be somewhat awkward and time consuming, particularly for aged or infirm persons who may lack manual dexterity or strength. This can be particularly problematic or frustrating when the air valve needs to be opened and closed numerous times in a relatively short period of time. 
         [0025]    As noted above, one of the beneficial uses of inflatable cushions is in the field of chiropracty and orthopaedics where cushions of variable firmness/softness may be required. In this field, in particular, it would be desirable to have a cushion in which the firmness/softness can be easily and readily varied to accommodate the differing needs of one or more patients. The abovementioned known and commonly used air valves are inconvenient in such situations owing to the need to rotate manually the outer cylindrical wall, between the valve-open and valve-closed positions, each time one wishes to change the firmness/softness of the cushion. 
         [0026]    Accordingly, a further aspect of the present invention is directed to an air-valve, adapted for use in an inflatable cushion, which at least ameliorates some of the problems and/or deficiencies of the existing air valves discussed above. In particular, this further aspect of the present invention is directed to an air-valve which is adapted to transition between a valve-open position and a valve-closed position without having to manually rotate an outer cylindrical wall of the air valve. 
         [0027]    Any reference herein to known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates, at the priority date of this application. 
         [0028]    According to a first aspect of the present invention, there is provided an inflatable cushion including:
       an inflatable body, having an upper surface and a lower surface, said body including an air-impermeable skin defining a chamber, an elastic foam core within said chamber and a sealable air valve; and   an external elastic foam layer substantially covering at least one of said upper and lower of surfaces;
 
wherein the density and hardness of the foam core and of the elastic foam layer differ by no more than about 30%.
       
 
         [0031]    Preferably, the density and hardness of the foam core and of the foam layer differ by no more than about 15%. It is particularly preferred that the density and hardness of the foam core and of the foam layer are substantially identical. The foam core and the foam layer may, therefore, be formed of the same material. 
         [0032]    In this first aspect of the invention, it is preferable that foam used in the foam core and the foam layer has a density of between about 20 kg/m 3  and 120 kg/m 3 . It is further preferred that the foam has a density of between about 30 kg/m 3  and 80 kg/m 3 . In a particularly preferred embodiment, the foam has a density of about 50 kg/m 3 . 
         [0033]    According to a second aspect of the present invention, there is provided an inflatable cushion including:
       an inflatable body, having an upper surface and a lower surface, said body including an air-impermeable skin defining a chamber, an elastic foam core within said chamber and a sealable air valve; and   an external elastic foam layer substantially covering at least one of said upper and lower of surfaces;
 
wherein:
   the foam core is formed of a foam having a density of between about 15 kg/m 3  and about 35 kg/m 3  and a hardness of between about 25 newtons and about 45 newtons; and   the foam layer is formed of a foam having a density of between about 35 kg/m 3  and about 65 kg/m 3  and a hardness of between about 35 newtons and about 95 newtons.       
 
         [0038]    The ‘hardness’ of a foam product is characterised as the force (expressed in Newtons) required to compress a standard sized piece of foam to 40% of its original height, is between 35 and 55 Newtons. 
         [0039]    In a preferred embodiment of the second aspect of the present invention, the foam core is formed of a foam having a density of between about 18 kg/m 3  and about 25 kg/m 3  and a hardness of between about 30 newtons and about 35 newtons. 
         [0040]    In a particularly preferred embodiment, the foam core is formed of a foam having a density of about 18 kg/m 3  and a hardness of about 35 newtons. 
         [0041]    In a further preferred embodiment of the second aspect of the present invention, the foam layer is formed of a foam having a density of between about 45 kg/m 3  and about 55 kg/m 3  and a hardness of between about 50 newtons and about 70 newtons. 
         [0042]    In a particularly preferred embodiment, the foam layer is formed of a foam having a density of about 52 kg/m 3  and a hardness of about 60 newtons. 
         [0043]    The following paragraphs, [035] to [060], relate to both the first aspect and the second aspect of the present invention (unless indicated to the contrary). 
         [0044]    Typically, the foam core occupies substantially all of the chamber of the inflatable body. This foam core may be adhered to an internal surface of the air-impermeable skin. This enables the inflation and deflation of the inflatable cushion to correspond entirely with the inflation and deflation of the chamber and inhibits any bubbling effect. 
         [0045]    As the above described inflatable cushion incorporates a foam core, within the chamber, this effectively causes the cushion to be self-inflating. Once the sealable air valve is opened, the foam core (which typically will have been compressed), and hence the cushion, will naturally tend towards an expanded/inflated state. That is, if the foam core is in a compressed state and the air valve is opened, the foam core will expand to its natural state, thereby causing the chamber to expand which causes air to be drawn in through the air valve. 
         [0046]    It is also preferred that the foam layer is adhered to at least one of said upper and lower surfaces of the inflatable body. In a particularly preferred embodiment, the foam layer substantially covers both of the upper and lower surfaces of the inflatable body. In this embodiment, it is preferred that the foam layer is adhered to both the upper and lower surfaces of the inflatable body. 
         [0047]    In a further preferred embodiment, the inflatable cushion further comprises a neck support strip extending substantially along at least one side of said cushion. The neck support strip may be formed of foam having a higher density and/or higher hardness factor than that of the foam of the external elastic foam layer. In this embodiment, it is particularly preferred that the neck support strip is positioned between the upper surface of the inflatable body and the foam layer or between the lower surface of the inflatable body and the foam layer. In a typical inflatable cushion for use as a pillow, which has a generally rectangular shape, the neck support strip typically extends substantially along at least one of the long sides of said cushion. 
         [0048]    Although the foam core and the foam layer may be formed of any suitable foam material, it is preferred that at least one of said foam core and said foam layer are formed of visco-elastic foam. 
         [0049]    It is particularly preferred that the foam layer is formed of visco-elastic foam. If desired, the foam core may also be formed of visco-elastic foam. 
         [0050]    Visco-elastic foam (also sometimes known as ‘slow recovery’ or ‘memory’ foam) is a low resilience′ (LR) foam which is better adapted to contour to the body shape of a user and/or to reduce pressure on the relevant portion of a user&#39;s body. Visco-elastic foams are typified by their slow recovery after compression. This characteristic of visco-elastic foam causes the foam to progressively conform to the shape of an object laid upon it (e.g. a human head) and then, once the object has been removed, to slowly re-assume its original shape. 
         [0051]    Other beneficial features of visco-elastic foams are their ability to dampen vibrations and absorb shocks. These features are particularly advantageous where users have chiropractic or orthopaedic problems. 
         [0052]    A further beneficial feature of visco-elastic foams is that they tend to respond to body temperature and ambient temperature, typically softening with heat. This further enhances the foam&#39;s ability to adjust to the shape or contour of the user&#39;s head or other body part. Accordingly, visco-elastic foams are particularly well suited for use as the foam material for the foam layer of the subject inflatable cushion. 
         [0053]    The visco-elastic foam used in the foam layer, according to the second aspect of this invention, preferably has a density of between about 15 kg/m 3  and 35 kg/m 3 . It is further preferred that the visco-elastic foam has a density of between about 18 kg/m 3  and 25 kg/m 3 . In a particularly preferred embodiment, the visco-elastic foam has a density of about 18 kg/m 3 . 
         [0054]    The firmness of visco-elastic foam is generally measured in terms of its ILD (indentation load deflection) rating. Generally, a 25% ILD rating indicates the weight required to achieve a 25% compression of a 4″ thick foam using a 50 square inch compression. 
         [0055]    The visco-elastic foam used in the present invention preferably has an ILD rating of from 10 pounds (4.5 kg) @ 25% ILD to 60 lbs (27 kg) @ 25% ILD. 
         [0056]    In one preferred embodiment of the first aspect of this invention, the relevant visco-elastic foam material is Dunlop Foam&#39;s Viscoflex® foam. 
         [0057]    In a preferred embodiment of the second aspect of this invention, the relevant visco-elastic foam material for the foam layer is Dunlop Foam&#39;s Viscoflex® foam. In this aspect of the invention, a visco-elastic foam material having a lower density is preferred for the foam core. 
         [0058]    Dunlop Foam&#39;s Viscoflex® foam is published as having the following technical parameters. Its nominal density is published as 52 kg/m 3 . Its hardness range, characterised as the force (expressed in Newtons) required to compress a standard sized piece of foam to 40% of its original height, is between 35 and 55 Newtons. Its indentation factor, that is, the ratio of forces required to compress the foam to 65% and to 25% of its original height, is 2.67 for the VF52-40 (white foam) and 2.11 for the VF52-60 (yellow foam). Its resilience is about 5% for the VF52-40 (white foam) and about 10% for the VF52-60 (yellow foam). According to Dunlop Foams, “resilience” is “measured by dropping a steel ball onto a standard sized piece of foam and measuring the distance that the ball bounces back. The height of the drop divided by the height of the bounce equals the foam&#39;s resilience percentage.” The low resilience level of the Viscoflex® foam, of from about 5% to 10%, is substantially lower than the resilience levels of other foams (such as those used for chairs, lounges and the like) which generally have resilience levels of between about 40% and about 60%. 
         [0059]    It is further preferred that the air-impermeable skin is formed of a substance which minimises any rustling sound when a user&#39;s head (or other body part) moves on the cushion. In one preferred embodiment of this aspect of the invention, the air-impermeable skin of the pillow is formed of latex rubber. Alternatively, the air-impermeable skin may be formed of vinyl. 
         [0060]    As will be appreciated, the inflatable cushion may be used as a pillow, a seat cushion, a back support, a leg support or in a number of other ways. 
         [0061]    In an embodiment of the invention in which the inflatable cushion is intended for use as a pillow and the air-impermeable skin of the cushion is formed of vinyl, a desired thickness of the vinyl is about 0.3 mm. 
         [0062]    The air-impermeable skin preferably includes a nozzle arrangement adapted to engage with the air valve so that the air valve is affixed to the nozzle. The air valve may be affixed to the nozzle arrangement by any suitable fastening means. One preferred fastening means is a simple thread arrangement whereby the air valve is threadably connected to (or disconnected from) the nozzle. The threadable connection may be achieved by the air valve having a threaded surface which is adapted to engage with a corresponding threaded surface of the nozzle, enabling the air valve to be ‘screwed’ onto and (removeably) secured to the nozzle. 
         [0063]    The inflatable cushion of this invention typically has a forward end and a rearward end. In one preferred embodiment, the cushion is thicker at the rearward end than the forward end. In this embodiment, the difference in thickness is generally between about 1 cm and 2 cm. 
         [0064]    In a further preferred embodiment, the inflatable cushion may further include a cut-out portion, adjacent the forward end, for receiving the neck or shoulder of a user. 
         [0065]    The foam layer on the upper surface of the inflatable body may include a corrugated surface. This corrugated surface may include a series of ridges and channels extending between opposed sides of the foam layer. These corrugations facilitate the movement of air along the channels, thereby enabling ventilation between the head (or other body part) of the user and the cushion. 
         [0066]    The inflatable cushion of the present invention may also have corrugations on the foam layer on the lower surface of the inflatable body. Typically, this part of the foam layer rests against the mattress of a bed and, having corrugations located on this part of the foam layer, further enhances the extent of ventilation around the cushion. Of course, having corrugations in the foam layer on both of the upper and lower surfaces makes both surfaces of the relevant cushion more adaptable for direct contact with a part of the user&#39;s body. 
         [0067]    The above described cushion is preferably adapted to enable the cushion to be inflated to a desired level of a user by operation of the sealable air valve. This enables a user to select between a firm or soft cushion and between a relatively thick or relatively thin cushion, without having to use different cushions. 
         [0068]    Similarly, this feature enables a single cushion, or at least a smaller range of cushions, to be used which will satisfy the differing requirements of a range of users (or of the same user at different times). Accordingly, this has significant cost benefits for users, including chiropractors, other health care providers and, ultimately, consumers. 
         [0069]    In an alternative embodiment of the invention, the inflatable body may include a plurality of chambers, an elastic foam core within each chamber and a sealable air valve associated with each chamber. These chambers may be independently adjusted to vary the extent of inflation (and therefore the resilience) of each chamber, as desired by a user. 
         [0070]    According to a third aspect of the present invention, there is provided a mattress comprising:
       a mattress body; and   an inflatable cushion, having an inflatable body which includes an air-impermeable skin defining a chamber, an elastic foam core within said chamber and a sealable air valve, said inflatable cushion being positioned within said mattress body;
 
wherein the sealable air valve is accessible at an external face of said mattress.
       
 
         [0073]    Preferably, the inflatable cushion may be locatable at more than one position within said mattress body so that it may underlie a desired portion of a user&#39;s body, such as the head, the shoulders, the back, the torso, the hips, the legs or the feet of said user. 
         [0074]    It is preferred that the air-impermeable skin is formed of a substance which minimises any rustling sound when a part of a user&#39;s body moves on the cushion. In one preferred embodiment, the air-impermeable skin of the cushion is formed of latex rubber. Alternatively, the air-impermeable skin may be formed of vinyl. When the air-impermeable skin of the cushion is formed of vinyl, a desired thickness of the vinyl is about 0.45 mm. 
         [0075]    The air-impermeable skin preferably includes a nozzle arrangement adapted to engage with the air valve so that the air valve is affixed to the nozzle. The air valve may be affixed to the nozzle arrangement by any suitable fastening means. One preferred fastening means is a simple thread arrangement whereby the air valve is threadably connected to (or disconnected from) the nozzle. The threadable connection may be achieved by the air valve having a threaded surface which is adapted to engage with a corresponding threaded surface of the nozzle, enabling the air valve to be ‘screwed’ onto and (removeably) secured to the nozzle. 
         [0076]    The mattress body may be formed of foam, pieces of foam, springs or any other materials typically used in the manufacture of mattresses, or a combination of such materials. 
         [0077]    In a preferred embodiment of this aspect of the invention, the mattress body includes a cavity adapted to receive the inflatable cushion. Preferably, the cavity has an opening in an upper surface of the mattress body adapted to enable the inflatable cushion to be inserted into the cavity. 
         [0078]    In a further preferred embodiment, the mattress body may comprise at least one removeable foam piece and the mattress is adapted so that the positioning of the inflatable cushion and the foam piece may be interchanged. This feature enables a user to change the positioning of the inflatable cushion from, say, beneath the user&#39;s head to, say, beneath the user&#39;s hips. 
         [0079]    The mattress may include more than one inflatable cushion. The mattress may also include more than one removeable foam piece. In a further alternative, the mattress may include one inflatable cushion and two or more removeable foam pieces, in which case the inflatable cushion may be interchanged with any one of the removeable foam pieces, thereby enabling the inflatable foam cushion to be located in any of a plurality of different positions within the mattress. 
         [0080]    The elastic foam core of the inflatable cushion may be formed of any suitable foam material. Preferably, the foam material of the foam core has a density of between about 20 kg/m 3  and about 35 kg/m 3  and a hardness of between about 50 newtons and about 120 newtons. In a particularly preferred embodiment, the foam material of the foam core has a density of between about 25 kg/m 3  and about 32 kg/m 3  and a hardness of between about 60 newtons and about 110 newtons. 
         [0081]    The foam used elsewhere in the mattress (as described above) preferably has a density of between about 30 kg/m 3  and about 70 kg/m 3  and a hardness of between about 30 newtons and about 100 newtons. It is particularly preferred that this foam has a density of between about 38 kg/m 3  and about 60 kg/m 3  and a hardness of between about 50 newtons and about 80 newtons. 
         [0082]    The foam core and/or the foam used elsewhere in the mattress (as described above) may be formed of visco-elastic foam. 
         [0083]    In a further preferred embodiment, the mattress further comprises an external frame positioned around the perimeter of at least a portion of the mattress body. Preferably, the frame extends around the entire perimeter of the mattress. The frame may be formed of any suitable material such as (but not limited to) foam (e.g. a hard foam) or plastic, or a textile material or a combination of these. 
         [0084]    The mattress described above may be of any size and/or shape. Typically, the mattress will be a single, double, queen or king sized mattress. Of course the mattress may also be a smaller size for use in a bassinet or a cot (for a baby or infant). Such smaller mattresses may also have applications in other products, such as babies&#39; prams and strollers. 
         [0085]    Where the mattress is a two-person mattress, intended for use by two persons (e.g. double, queen and king size), the mattress typically includes a first half for one user and a second half for another user. The two-person mattress may include at least one of the inflatable cushions on just one half of the mattress or on both halves. As is the case with single-bed mattresses, such as those described above, two-person mattresses may include at least one removeable foam piece enabling the positioning of each inflatable cushion and a foam piece to be interchanged. 
         [0086]    In the two-person mattress described above, a user on one half of the mattress can have an inflatable cushion positioned under a desired portion of the user&#39;s body and at a desired degree of inflation and this will be quite independent of the positioning and degree of inflation of the inflatable cushion on the other half of the mattress. 
         [0087]    This enables a range of differing settlings of a two-person mattress, adapted to accommodate the different requirements of the two persons. 
         [0088]    Also, in respect of a two-person mattress, it is preferred that the mattress will include a separating portion adjacent a centre line of the mattress adapted to separate at least a section of one half of the mattress (for one user) from an adjacent section of the other half of the mattress (for another user). The separating portion may simply comprise a gap between adjacent sections of the mattress halves. Alternatively, the separating portion may comprise a separation strip formed of any appropriate material, such as foam, plastic or a textile material. 
         [0089]    In an optional embodiment of this third aspect of the invention, the inflatable cushion of the mattress is an inflatable cushion according to the first aspect of the present invention. 
         [0090]    In an alternative optional embodiment of this third aspect of the invention, the inflatable cushion of the mattress is an inflatable cushion according to the second aspect of the present invention. 
         [0091]    However, it is preferred that, when the inflatable cushion is intended for use within a mattress and when the air-impermeable skin is formed of vinyl, the thickness of the vinyl is about 0.45 mm. 
         [0092]    In a particularly preferred embodiment, the mattress further includes at least one elastic foam layer positioned above the inflatable cushion. Preferably, the elastic foam layer is formed of visco-elastic foam, such as described above. In this preferred embodiment, it is further preferred that there is also at least one layer of latex rubber located above the inflatable cushion. This layer of latex rubber provides a sensation of additional firmness to the mattress. In this preferred embodiment, the layer of latex rubber may be placed directly over the inflatable cushion or it may be placed above a layer of elastic foam (which may be located directly over the inflatable cushion). 
         [0093]    In the mattress described above, it is preferred that the sealable air valve of the or each inflatable cushion is accessible at a side face of the mattress. This is to facilitate easy access to, and use of, the air valve by a user. 
         [0094]    Accordingly, where the mattress comprises an external frame, the frame includes a hole adapted to enable access to the air valve. The frame may include at least one hole on each side of the mattress. This will enable the inflatable cushion to be inserted in such a way that the air valve is accessible at a desired side of the mattress (e.g. not against a wall). 
         [0095]    The mattress may also comprise a covering which, preferably, covers the entire mattress. This covering is typically formed of a textile material. The covering provides the mattress with greater stability and improved ease of handling. Of course, the covering should include a hole adapted to enable access to the air valve. 
         [0096]    In another preferred embodiment, the inflatable cushion may have a convex upper surface when inflated. This convex surface may be adapted to extend above the upper surface of the rest of the mattress. This extending convex surface of the inflatable cushion can be used to provide additional support to a desired part of the body (such as the lower back) which may require or benefit by such additional support. 
         [0097]    According to another aspect of this invention, there is provided a method of manufacturing an inflatable cushion, according to the first aspect or the second aspect of this invention, said method including:
       forming a cushion having an internal cavity and an opening for accessing the internal cavity;   inserting the inflatable body into the internal cavity whilst locating the sealable air valve so that it is accessible by an external user; and   sealing the opening.       
 
         [0101]    According to a further aspect of this invention, there is provided a method of using an inflatable cushion, according to the first aspect or the second aspect of this invention, said method including:
       opening the sealable air valve;   allowing air to enter the inflatable body up to a desired inflation level; and   sealing the sealable air valve       
 
         [0105]    The air-impermeable skin of the inflatable cushion can be formed of any suitable material including latex rubber or vinyl. 
         [0106]    The inflatable cushion can have a forward end and a rearward end, said cushion being thicker at the rearward end than the forward end. 
         [0107]    Said cushion can include a cut-out portion, adjacent the forward end, for receiving the neck of a user. 
         [0108]    The foam layer on the upper surface of the inflatable body of the inflatable cushion can include a corrugated surface. The corrugated surface can include a series of ridges and channels extending between opposed sides of the foam layer. 
         [0109]    Said inflatable cushion can be adapted to enable the cushion to be inflated to a desired level of a user by operation of the sealable air valve. 
         [0110]    The inflatable body of the inflatable cushion can include a plurality of chambers, an elastic foam core within each chamber and a sealable air valve associated with each chamber. 
         [0111]    According to another further aspect of the invention, there is provided a valve assembly including:
       a valve body having a first end;   a valve member adapted to seal an opening, the valve member having an open position in which the valve member allows an air passage through the opening, and a closed position in which the valve member seals the opening;   an actuating means associated with the body and the valve member;
 
wherein a first actuation of the actuating means causes the valve member to be in the open position, and a second actuation of the actuating means causes the valve member to return to its closed position, wherein the first and second actuation each involve an application of a force upon the actuating means towards the valve member.
       
 
         [0115]    The first actuation can cause the actuating means to move from an extended position to a retracted position, and the second actuation can return the actuating means to the extended position. 
         [0116]    The actuating means and the valve member can be both biased away from the same end of the body. 
         [0117]    The first actuation can cause one of the valve member and the actuation means to rotate by a discrete amount with respect to the other, and the second actuation can cause the one of the valve member and the actuation means to rotate by the same discrete amount and in the same direction with respect to the other. 
         [0118]    An interior surface of the body can be profiled so as to keep the valve member in the open position after the first actuation. 
         [0119]    One of the interior surface of the body and an exterior surface of the valve member, can be profiled to have evenly spaced longitudinal ribs, there being channels interspersed between the ribs, and the other one of the exterior surface of the valve member and the interior surface of the body can include fins adapted to fit into and move longitudinally relative to the channels. 
         [0120]    Every alternate channel can have a raised floor, and the fins can be adapted to fit only into the alternate channels without the raised floors. 
         [0121]    The application of the force applied in the first actuation can cause the fins to move longitudinally within and then clear the alternate channels without the raised floors, and upon a release of the force applied in the first actuation, the fins can be biased to re-enter the channels, but are prevented from re-entering the channels by the raised floors. 
         [0122]    The ribs and the raised floors of the alternate channels can each have chamfered ends, the chamfered ends of the ribs and the raised floors having a same angle of inclination, and the ends of the fins adjacent the ribs are also chamfered and have the same angle of inclination. 
         [0123]    The longitudinal ribs and the channels can be located on the interior surface of the body, and the actuating means can have external ribs adapted to fit into and move relative to the channels. 
         [0124]    The external ribs of the actuating means can be profiled to cooperate with a shape of the valve member. 
         [0125]    The external ribs of the actuating means can be each chamfered to abut a zigzag formation provided on the valve member. 
         [0126]    The valve assembly can have a first biasing means which biases the actuating means in a direction away from the body. 
         [0127]    The actuating means can include a shaft which defines a through passage, and the valve member includes a stem that is adapted to be received by the through passage. 
         [0128]    The valve assembly can have a second biasing means which biases the valve member in a direction away from the body. 
         [0129]    The actuating means can include an actuation surface adjacent the shaft. 
         [0130]    The head of the actuation surface can include one or more through apertures. 
         [0131]    The actuation surface can include an inner perimeter and an outer perimeter, and the shaft of the actuating means extends from the inner perimeter, the inner perimeter defining an opening into the through passage of the shaft. 
         [0132]    The outer perimeter of the shaft can extend into a circumferential flange. 
         [0133]    The body can include a housing. 
         [0134]    The housing can include a chamber adjacent one end, and the actuating means is at least partially located in the chamber. 
         [0135]    The housing can include a chamber associated with the valve member, in which said valve member is at least partially located. 
         [0136]    The actuating means can be adapted to be moved relative to said one end. 
         [0137]    Said one end can be an open end. 
         [0138]    The opening can be provided at a second end of the body, the second end being opposite the first end, wherein in its closed position, the valve member seals the second end of the body, thereby closing the air passage. 
         [0139]    The valve member can carry an O-ring adapted to seal the second end of the body. 
         [0140]    The opening is provided on a device adapted to be sealed by the valve member. 
         [0141]    The valve assembly housing can further include a support flange for supporting the valve assembly on the inflatable body. 
         [0142]    According to a still further aspect of the invention, there is provided a valve assembly including:
       a housing having a first chamber extending from a first open end and a second chamber extending from a second open end, said second chamber being in open communication with the first chamber;   a valve plug, at least a portion of which is located within the second chamber, and which is adapted to seal the second open end;   a valve actuating means, at least a portion of which is located within the first chamber,
 
wherein said valve plug and said valve actuating means are adapted so that, upon a single push of the valve actuating means, the valve plug moves from a valve-open position to a valve-closed position and upon a subsequent push of the valve actuating means, the valve plug moves from a valve-closed position to a valve-open position.
       
 
         [0146]    The valve plug can include a first end, an intermediate section and an aperture sealing end opposed to the first end; and the valve actuation means can include a first end and an opposed exposed end wherein the aperture sealing end of the valve plug is adapted to seal the second open end of said second chamber and the exposed end of the valve actuation means is adapted to be pushed by a user. 
         [0147]    The first open end of the first chamber can be opposed to the second open end of the second chamber. 
         [0148]    The valve actuating means can include a pushing surface; and the valve plug can include a pushed surface adapted to be pushed by the pushing surface, wherein when the valve actuating means is pushed, the pushing surface of the valve actuating means pushes against the pushed surface of the valve plug. 
         [0149]    The first end of the valve actuation means can be located within the second chamber of the housing. 
         [0150]    The valve plug can include a plurality of ribs extending radially from the intermediate section; and the valve actuation means can include a plurality of radially extending ribs adjacent said first end; and the second chamber can include an internal surface having a plurality of substantially uniform channels adapted to receive the ribs of the valve plug and the ribs of the valve actuation means. 
         [0151]    The channels, the ribs of the valve plug and the ribs of the valve actuation means can be configured so as to enable the ribs to move along said channels when valve actuating means is pushed. 
         [0152]    The valve assembly can have a first biasing means adapted to bias the valve actuating means back towards its original position after being pressed by a user. 
         [0153]    The channels and the ribs of the valve plug can be configured so that, when the valve plug moves a predetermined distance along the channels the ribs of the valve plug exit the channels and, under the influence of a second biasing means, the valve plug is caused to rotate within the second chamber. 
         [0154]    The second biasing means can be adapted to bias the valve plug towards the valve actuation means. 
         [0155]    The valve plug can include a set of inclined surfaces positioned between the first end and the intermediate section of the valve plug, and exposed ends of the ribs of the valve actuation means press against said inclined surfaces under the influence of the second biasing means. 
         [0156]    The inclined surfaces of the valve plug and the exposed ends of the ribs of the valve actuation means can be adapted so that when, upon pushing of the valve actuation means, the ribs of the valve plug exit the channels, the valve plug is caused to rotate relative to the valve actuation means, under the influence of the second biasing means. 
         [0157]    The internal surface of the second chamber can include a set of inclined ledges in between openings of said channels. 
         [0158]    The inclined ledges can include adapted to abut the exposed ends of the ribs of the valve actuation means after the valve plug has been caused to rotate and, under the influence of the first biasing means, guide each of the ribs into an adjoining channel of the second chamber. 
         [0159]    In order to facilitate the securing of the valve assembly to the impermeable skin of an inflatable pillow or an inflatable cushion, a surface of the valve body may comprise a threaded section. This threaded section is adapted to engage with a corresponding threaded section of a surface of a nozzle arrangement of the impermeable skin so that the valve assembly can be ‘screwed’ into and secured within the nozzle arrangement. 
         [0160]    The invention further provides an inflatable cushion including an inflatable body having a sealable air valve according to the valve assembly described above. 
         [0161]    The invention further provides a mattress including at least one inflatable cushion which includes an inflatable body have a sealable air valve according to the valve assembly described above. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0162]    An embodiment or embodiments of the aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings. 
           [0163]      FIG. 1  is a perspective view of an inflatable cushion according to a preferred embodiment of a first aspect of the present invention (with open side), in a deflated formation. 
           [0164]      FIG. 2  is a perspective view of the inflatable cushion of  FIG. 1 , in an inflated formation. 
           [0165]      FIG. 3   a  is a perspective view of the inflatable cushion of  FIG. 2  (with closed side). 
           [0166]      FIG. 3   b  is an alternate perspective view to that shown in  FIG. 3   a.    
           [0167]      FIG. 4  is a perspective view of the inflatable cushion of  FIG. 3  (with closed side) showing internal inflatable body in broken lines. 
           [0168]      FIG. 5  is a perspective view of the inflatable cushion of  FIG. 1 , with the internal inflatable body removed. 
           [0169]      FIG. 6  is a perspective view of the inflatable cushion of  FIG. 1 , with the internal inflatable body in position, prior to the closing up of the cushion (during manufacture). 
           [0170]      FIGS. 7   a  to  7   d  are perspective views of an inflatable cushion according to an alternative preferred embodiment of the first aspect of the present invention. 
           [0171]      FIGS. 8   a  to  8   c  are schematic representations of mattresses, showing different orientations of components thereof, according to preferred embodiments of a further aspect of the present invention. 
           [0172]      FIGS. 9   a  to  9   c  are schematic representations of mattresses, showing different orientations of components thereof, according to alternative preferred embodiments of the further aspect of the present invention. 
           [0173]      FIG. 10  is a sectional view in perspective, of a valve assembly, according to a preferred embodiment of another further aspect of the present invention, fitted onto the inflatable cushion of any one of  FIGS. 1 to 7 . 
           [0174]      FIG. 11  is a perspective view in section, of the valve assembly of  FIG. 10 . 
           [0175]      FIG. 12  is a cross section of the housing of the valve assembly of  FIG. 10 . 
           [0176]      FIG. 13  is a cross section of the actuating means in the valve assembly of  FIG. 10 . 
           [0177]      FIGS. 14A and 14B  show lower and upper perspective views of the actuating means of the valve assembly of  FIG. 10 . 
           [0178]      FIG. 15  is a perspective view of the valve in the valve assembly of  FIG. 10 . 
           [0179]      FIG. 16  is cross section of the valve of  FIG. 15 . 
           [0180]      FIG. 17  is cross section of the valve assembly of  FIG. 7 , positioned within an inflatable cushion of  FIG. 7 , with the valve in the open position. 
           [0181]      FIG. 18  is cross section of the valve assembly of  FIG. 10 , with the valve in the open position. 
           [0182]      FIG. 19  is a cross section of the housing of the valve assembly of  FIG. 10 . 
           [0183]      FIG. 20  is a cross section of the valve assembly of  FIG. 10 , with the valve in the closed position. 
           [0184]      FIG. 21  is a cross section of the housing of the valve assembly of  FIG. 10 . 
           [0185]      FIG. 22  is a partial perspective view of the housing, the valve, and the first biasing means of the valve assembly of  FIG. 10 . 
           [0186]      FIG. 23  is a bottom perspective view of the housing and the actuating means of the valve assembly of  FIG. 10 . 
       
    
    
     DETAILED DESCRIPTION 
       [0187]    A preferred embodiment of the invention will now be described with reference to the above drawings. 
         [0188]    The Inflatable Cushion 
         [0189]      FIGS. 1 ,  2  and  4  show an inflatable cushion  1 , according to a preferred embodiment of the invention, having an internal inflatable body  2  and an external elastic foam layer  3 . The inflatable body  2  has an upper surface  24  (shown in  FIG. 6 ) and a lower surface (not clearly shown in the drawings). The inflatable body  2  also includes an air-impermeable skin  20 , which defines an internal chamber, and a sealable air valve  21 . This sealable air valve  21  is located at an end of the inflatable body  2  and extends from the side  33  of the cushion  1 . 
         [0190]    The external elastic foam layer  3  covers the upper and lower surfaces of the inflatable body  2 . This foam layer  3  is adhered to these upper and lower surfaces of the inflatable body  2 . 
         [0191]    An upper portion  30  of the foam layer  3 , which covers the upper surface  24  of the inflatable body  2 , is corrugated, having a series of ridges  31  and channels  32  which extend transversely between opposed sides  33 ,  34  of the cushion  1 . These ridges  31  and channels  32  facilitate ventilation between a user&#39;s head (or other body part) and the cushion  1 . 
         [0192]    A lower portion  35  of the foam layer  3 , which covers the lower surface of the inflatable body  2 , is also corrugated, having a series of smaller ridges and channels which, again, extend transversely between opposed sides  33 ,  34  of the cushion  1 . These ridges and channels facilitate ventilation around the pillow. 
         [0193]    The cushion  1  has a forward end  11  and a rearward end  12 . The rearward end  12  is slightly thicker than the forward end  11 , typically by about 1.5 cm. The forward end  11  also includes a cut-out section  13  adapted to receive the neck or shoulder of a user. 
         [0194]      FIG. 3   a  shows the above described cushion  1  also having a foam side panel  14 . Preferably, both sides of the cushion  1  have side panels  14 . These side panels effectively close the cushion  1  and retain the inflatable body  2  within the external foam layer  3 . In this embodiment, the sealable air valve  21  extends through an aperture in the adjoining side panel  14 . 
         [0195]      FIG. 4  shows the above inflatable cushion  1  with the inflatable body  2  in position (shown in broken lines) surrounded by the elastic foam layer  3 . 
         [0196]      FIG. 5  shows the above inflatable cushion  1  (without side panel  14 ) prior to insertion of the inflatable body  2 . 
         [0197]      FIG. 6  shows the above inflatable cushion  1 , during the manufacture of same, after insertion of the inflatable body  2  into position, but prior to closure of the cushion. The lower surface of the inflatable body  2  is adhered to an adjoining surface of the foam layer  3 . The cushion is then closed and the upper surface  24  of the inflatable body  2  is then adhered to an adjoining surface of the foam layer  3 . 
         [0198]      FIGS. 7   a  to  7   d  show an alternative preferred embodiment of the inflatable cushion  1 . In this embodiment, only one face, being the upper face, of the cushion has corrugations for providing improved air flow around the vicinity of a user&#39;s head. The opposite face, being the lower face, is substantially flat. 
         [0199]      FIGS. 7   a ,  7   b  and  7   d  show side faces of the inflatable cushion comprising foam walls having an aperture  121  adapted to enable a portion of the valve assembly to extend through.  FIG. 7   c  shows a portion (being an actuating portion) of the valve assembly located outside the aperture  121 . 
         [0200]      FIGS. 8   a  to  8   c  show schematic representations of a single-bed mattress having portions: A; A and B; or A, B and C. These portions represent positions in which an inflatable cushion (such as described above) may be located. 
         [0201]    In  FIG. 8   a , the inflatable cushion is located in position A, being the only available position. 
         [0202]    In  FIG. 8   b , the inflatable cushion may be located in position A or position B. When in either of these positions, a removeable foam piece is generally located in the other position. Alternatively, inflatable cushions could be placed in both positions A and B. 
         [0203]    In  FIG. 8   c , the inflatable cushion may be located in position A, position B or position C. When in one of these positions, a removeable foam piece is typically located in each of the other positions. Alternatively, inflatable cushions could be placed in one or both of these other positions. 
         [0204]      FIGS. 9   a  to  9   c  show schematic representations of a two-person mattress having portions: A and A′; A, A′, B and B′; or A, A′, B, B′, C and C′. These portions represent positions in which an inflatable cushion (such as described above) may be located. Generally, a two-person mattress will be made symmetrically in the sense that an equal number of portions, for location of the inflatable cushion, will be formed on each half of the mattress. 
         [0205]    In  FIG. 9   a , the inflatable cushions are located in positions A and/or A′, being the only available positions. 
         [0206]    In  FIG. 9   b , the inflatable cushions may be located in one or more of the positions A, A′, B and/or B′. When in any of these positions, a removeable foam piece is typically located in the other position(s). 
         [0207]    In  FIG. 9   c , the inflatable cushion may be located in one or more of the positions A, A′, B, B′, C and/or C′. When in any of these positions, a removeable foam piece is typically located in the other position(s). 
         [0208]      FIGS. 8   a  to  8   c  also show the location  21   a  of the actuating portion of the valve assembly of the inflatable cushion (when said cushion is located at the adjoining position). 
         [0209]    The Valve Assembly 
         [0210]      FIGS. 10 to 13  depict a valve assembly (or a part thereof) for use with the inflatable cushion described above. For ease of reference, the end of the valve assembly which is located on the outside of the cushion will be referred to as the upper or outer end, and the opposite end will be referred to as the lower or inner end. 
         [0211]    With reference to  FIG. 10 , the valve assembly  21  includes a body or housing  50  that is supported on the side  33  of the cushion  1 , and also by the inflatable body  2 . The housing  50  contains and supports a valve plug or valve member  52  which engages a valve seat  50 . 1  provided around an opening  50 . 2 , to open and close the airflow path between the outside of the cushion  1  and the inflatable body  2 . The valve member  52  is moved by an actuating means  54  which is user accessible from outside the cushion  1 . In the drawings the actuating means  54  is shown as a push button. However it is understood that other actuating means  54  may be used. 
         [0212]    The housing  50  is open ended, having a first open end  51  that is adjacent to the exterior of the cushion  1 . An opposite second open end  53  is located toward the interior of the cushion  1 . A first chamber  50 A extends from the first open end, and a second chamber  50 B extends from the second open end, the two chambers being in open communication with each other. The actuating means  54  is partially located in the first chamber, and the valve  52  is partially located in the second chamber. 
         [0213]    As shown in  FIGS. 10 and 11 , the housing  50  has a generally cylindrical main body  57  and a flange  56  which is provided around the first open end  51  of the housing  50 . 
         [0214]    When assembled the flange  56  is supported by the outside surface of the cushion  1 . The main body  51  is sized to fit into an opening in the cushion which accommodates the valve assembly  51 . The outer diameter of the flange  56  is larger than the diameter of the opening in the cushion  1 , thereby supporting the housing  50  on the external elastic foam layer  3 . The lower portion of the inside surface of the main body  51  is threaded. As will be described, this is to help secure the housing  50  onto a neck which is supported on the internal inflatable body  2  of the cushion  1 . 
         [0215]    The housing  50  also includes an interior wall  58  which extends transversely into the interior of the housing  50 . The interior wall  58  is located between the free ends of the main body  51 , and can be considered as dividing the housing  50  into its first and second chambers  50 A and  50 B. The interior wall  58  extends from the inside wall of the main body  51 , into a longitudinal interior tube  60 . 
         [0216]    As shown in  FIGS. 12 and 23 , the tube  60  has a plurality of, in this case eight, ribs  62  provided along its internal surface. The ribs  62  are evenly spaced apart, so that a plurality of grooves or channels  64  and  64 A are interspersed between the ribs  62 . Each of the ribs  62  has a chamfered or bevelled lower edge  63 . The plurality of channels include the same number of deeper channels  64  and shallower channels (or “obstructed channels”)  64 A which are alternately arranged. Every other channel is a shallower channel  64 A that has a floor  65 A (best seen in  FIG. 20 ) that is raised with respect to the internal surface of the tube  60 . The raised floor  65 A also has a lower end  63 A that is chamfered to the same angle as the lower edges  63  of the ribs  62 . Therefore, the channels  64  alternate between having a raised end chamfered base and not having a raised and chamfered base. The ribs  62  extend through the whole length of the tube  60  but this is a preferment. The internal wall of the tube  60  gradually thins out toward the lower end of the tube  60 , so as to provide the valve seat  50 . 1   
         [0217]    As best seen in  FIG. 23 , the housing  50  can optionally include formations  67  extending radially from the internal surface of the tube  60 . The formations  67  are located in the alternate deeper channels  64 , and are located adjacent the first housing chamber  50 A. In use, the formations  67  help guide and centre the actuating means  54  with respect to the housing  50 , so that the actuating means can better maintain its central location as it travels in the channels  64  and  64 A. As will be explained, the deeper channels  64  are provided so that fins  86  provided on the valve member  52  can travel longitudinally within these channels. Therefore, the deeper channels  64  need to have sufficient length to allow the movements of the valve member  52  in closing and opening the valve assembly. In embodiments where the formations  67  are provided, the deeper channels  64  need to have sufficient length to allow a full range of the movement of the valve member and also accommodate the formations. 
         [0218]      FIGS. 13 ,  14 A and  14 B depict the actuating means  54  in more detail. The actuating means  54  has a head  68 . The head  68  in this embodiment has an annular shape, with an inner perimeter  100  and an outer perimeter  102 . In other embodiments the head  68  can assume a different configuration. A downwardly depending skirt  104  extends from the outer perimeter  102  and toward the interior of the cushion  1  (not shown). A shaft  70  extends from the inner perimeter  100 . The shaft  70  and skirt  104  are approximately perpendicular to the annular head  68 . The inner perimeter  100  defines an opening for the central through hole  72  that runs through the shaft  70 . One or more apertures or holes  74  are provided around the inner perimeter  100  and through the head  68 . 
         [0219]    A flange  73  extends transversely from the inside surface of the shaft  70  into the central through hole  72 . As will be explained later the flange  73  serves to partially narrow or restrict the central through hole or passage  72 . Structures other than a flange can be used. For instance, a plurality of stubs or arcs, or the like, which extend transversely into the through hole or passage  72  can be used. The outside surface of the shaft  70  has a series of axially extending, circumferentially located, ribs  103 . As will be explained later, the shaft  70  is sized to fit into the tube  60  of the housing  50 . The ribs  103  on the shaft  70  are dimensioned to slide freely in all of the channels  64  and  64 A formed into the inside surface of the tube  60 . When assembled, the head  68  of the actuating button  54  is located within the first chamber  50 A of the housing  50 . A spring  76  (shown in  FIG. 8 ) is provided around the shaft  70 , and has one end which is held within the space defined between the outer circumference of the shaft  70  and the inner circumference of the flange  104 . In use, the spring bias is held between the head  68  of the actuating button  54  and the interior wall  58  of the housing  50 . 
         [0220]      FIGS. 15 and 16  depict the valve member (or “valve plug”)  52 . The valve member  52  includes a clicker formation  78 . One end of the clicker formation  78  extends axially from a stem  80  that is smaller in diameter than the clicker formation  78 . The stem  80  has a blind hole  84 . This blind hole  84  is threaded, and is located through the end of the stem  80  that is located away from the clicker formation  78 . The opposite end of the clicker formation  78  includes a circumferential skirt  82  provided around the perimeter of that end of the clicker formation  78 . The skirt can be angled and so flares outwardly from the clicker formation  78 . However the skirt  82  does not need to be angled. 
         [0221]    The clicker formation  78  has a plurality of, in this case four, axially extending and evenly spaced, exterior fins  86  which are evenly spaced around the stem  80 . There are half as many fins  86  as there are internal ribs  62  in the housing  50 . Each fin  86  extends generally axially along the base of the stem  80 . The free end of each fin  86  also has a chamfered or inclined surface  86 A, which is chamfered to the same angle as the chamfered edges  63  of the housing  50 . A zigzag or sinusoidal formation  90  is formed around the stem  80  of the valve member  52  and located adjacent to the clicker formation  78 . Each alternate surface of the zigzag formation  90  is also chamfered to approximately the same angle as the inclined surfaces of the fins  86 . Referring to each rising and falling surface of the zigzag formation  90  as a tooth, there are twice as many teeth in the zigzag or sinusoidal formation  90  as there are fins  86  on the clicker formation  78 . Said another way, there are as many teeth in formation  90 , as internal ribs  62 . 
         [0222]    Referring again to  FIG. 11 , the clicker formation  78  is sized to fit into the tube  60  of the housing  50 . The fins  86  are sized to slide freely in the deeper channels  64 , but cannot fit into the shallower channels  64 A. The stem  80  is sized to fit through the interior wall  58  and extends into the central through hole  72  of the shaft  70  of the actuating means  54 , so that the ends  55  of the ribs  103  on the shaft  70  abut the zigzag formation  90  on the clicker formation  78 . 
         [0223]    As shown in  FIGS. 12 ,  17 ,  18 ,  19  and  20 , the valve body  50  includes an annular cavity  110  having a threaded wall  111 . This annular cavity  110  is adapted to receive an annular nozzle  112  of the air-impermeable skin of an inflatable pillow or cushion. The annular nozzle  112  includes a threaded surface  113 , as shown in  FIG. 17 . 
         [0224]    Assembly of the Valve Components 
         [0225]    Referring to  FIG. 17 , when the components are assembled, the actuating button  54  is at least partially located in the first chamber  50 A of the housing  50 . The head  68  of the actuating button  54  fits within the space defined by the flange  56  of the housing  50 . The shaft  70  of the actuating button  54  fits through the interior wall  58  and into the tube  60  of the housing main body  51 . The valve member  52  is inserted into the main housing after the actuating means  54  has been appropriately positioned in the housing  50 . The shaft  70  of the actuating means  54  fits through the intermediate housing interior wall  58 , i.e. the outer dimension of the shaft  70  of the actuating means  54  is the same as the inner dimension of the housing interior wall  58 . Also, the shaft of the screw  92  seals the intermediate ring  73  of the actuating means  54 . 
         [0226]    The valve stem  80  (i.e. first end of the valve) is accommodated in the central through hole  72  of the shaft  70 , and the opposed end of the valve member  52  seals the second chamber  50 B of the housing  50  by engaging the valve seat  50 . 1 . The ribbed end  55  of the shaft  70  abuts and engages zigzag formation  90  on the clicker formation  78 . The shaft&#39;s ribbed end  55  is considered a pushing surface of the actuating means  54 , and the zigzag or sinusoidal formation  90  is considered a pushed surface of the valve member  52 . The tension spring  76  is biased between the head  68  of the button  54  and the interior wall  58  of the housing  50 . 
         [0227]    The screw  92  fits through the central through hole  72  of the actuating means  54  and is received by the blind hole  84  in the valve stem  80 . Only the shaft of the screw  92  is dimensioned to fit through the ring  73  provided inside the actuating means  54 . The head  93  of the screw  92  is larger in diameter than the inner diameter of the ring  73  and cannot pass through the ring. A second tension spring  96  is provided around the shaft of the screw and tensioned between the ring  73  and the enlarged head  93  of the screw. The screw  92  can be a shoulder screw, where the threaded portion of the shoulder screw engages the internal thread of the blind hole  84  of the valve stem  80 . The second tension spring  96  is provided around the shaft of the shoulder screw, and the shoulder indirectly engages the ring  73  via the second spring  96 . 
         [0228]    The larger spring  76  provided around the shaft  70  of the actuating means  54  biases the actuating means  54  toward the outside of the cushion. The second and smaller spring  96  biases the valve  52 , toward the first chamber  50 A. 
         [0229]    The Air Path 
         [0230]    In use, an O-ring  98  is provided around the base of the valve member  52 , so that it is retained between the skirt  82  of the valve member  52  and the valve seat  50 . 1 . The bias of the second spring  96  urges the valve member  52  to close the opening  50 . 2  by pushing the O-ring  98  onto the valve seat  50 . 1 . When the valve member  52  is in its closed position, the skirt  82  presses against the O-ring  98 , which is in turn pressed against the valve seat  50 . 1 , sealing off the air pathway between the inflatable cushion body and the outside. 
         [0231]    With reference to  FIGS. 18 and 20 , air can enter the holes  74  in the actuating means  54 , and then enter the second chamber  50 B via the space provided between the exterior ribs  103  of the actuating means  54 . The second chamber  50 B is sealed by the O-ring  98  when the valve  52  is in the closed position. When the valve  52  is in the open position the second chamber  50 B is unsealed, allowing air to enter into the cushion to inflate the cushion. 
         [0232]    Operation of the Valve Assembly 
         [0233]    As shown in  FIGS. 17 to 20 , to open the valve  52  so as to allow the cushion to inflate, the user pushes on the actuating means  54  once, to move the actuating means  54  from an extended position (see  FIG. 17 ) into a retracted position (see  FIG. 15 ). As the actuating means  54  is pushed toward the second chamber  50 B, the head  68  of the actuating means  54  compresses the first biasing means  76 . Also the intermediate ring  73  of the actuating means  54  is moved toward the second chamber  50 B, permitting the second biasing means  96  provided around the screw  92  to expand. 
         [0234]    As the second biasing means  96  expands, it biases the valve member  52  toward the first chamber  50 A, causing the zigzag formation  90  of the valve  52  to abut the ribbed end  55  of the actuating means  54 . At this point, the user has not released the actuating means  54 , therefore an actuation force is still applied upon the actuating means  54 . The ribbed end (i.e. pushing surface)  55 , moved by the actuation force, pushes on the zigzag pattern or formation  90  (i.e. pushed surface)  90  of the valve  52 . The valve fins  86  are therefore pushed to exit the deeper interior channels  64  in the housing  50 . As the valve fins  86  exit the channels  64 , the valve  52  is permitted to move in a direction away from the first chamber  50 A. The valve skirt  82 , and hence the O-ring  98 , are therefore moved away from the valve seat  50 . 1 , thereby unsealing the opening  50 . 2  and thus the air path into the cushion. 
         [0235]    The ends  55  of the ribs  103  of the actuating means  54  have a chamfered or bevelled profile, and the zigzag formation  90  which includes a similarly inclined surface. Therefore as the ribbed ends  55  contact the zigzag formation  90 , they tend to slide down, and around, the inclined surface of the zigzag formation  90 . This movement causes the valve  52  and the actuating means  54  to slightly rotate with respect to each other. This first slight rotation does not occur whilst the fins  86  of the valve member  52  are constrained by the walls of the housing&#39;s channels  64 . Upon the fins  86  existing the channels  64 , however, the valve member  52  is permitted to rotate by an amount that allows the ribs  103  to travel down and around one inclined surface of the zigzag formation  90 . 
         [0236]    Upon a release of the actuation force by the user, the first biasing means  76  biases the actuating means  54  to return toward the first chamber  50 A. The valve member  52  is carried by the actuating means  54  because the head of the screw  92  is carried by the actuating means  54 . Therefore the valve  52  also tends to return toward the direction of the first chamber  50 A. 
         [0237]    With reference to  FIG. 19 , as the return motion of the valve member  52  is initiated by a pushing force, the inclined surfaces  86 A of the valve fins  86  abut and travel along the inclined edges  63  of the housing ribs  62 . The travel continues as the valve fins  86  move along the raised floors  63 A of the shallower channels  64 A. The valve fins  86  cannot re-enter the shallower channels  64 A as they are blocked by the raised floors  63 A. The movement of the fins  86  is then stopped by the sidewall  63 B of the shallower channels  64 A. Therefore, the valve member  52  rotates, whilst inclined surface  86 A travels along the inclined edges  63 ,  63 A of the housing ribs  62  and the shallower channels  64 A, with respect to the actuating means  54 . The rotation is stopped when the movement of the valve fins  86  is stopped. As the fins  86  cannot enter the shallower channels  64 A, the valve member  52  is retained in its open position. Consequently, the actuating means  54  is retained in a retracted position. 
         [0238]    As shown in  FIGS. 20 and 21 , to close the valve member  52  the user applies a second actuation force on the actuating means  54 . Again, the same actions which lead to first relative rotational movement of the valve  52  are repeated, consequently there is a second relative rotational movement of the valve  52 . Also the valve fins  86  are now pushed down sufficiently so as to be clear of the internal ribs  62  of the housing  50 . The inclined surface  86 A of the valve fins  86  now clear the obstructing sidewalls  63 B of the shallower channels  64 A. 
         [0239]    When the user releases the actuating means  54 , again the valve member  52  tends to return toward the first chamber  50 A. As the valve member  52  returns, the inclined surfaces  86 A of the valve fins travel along the inclined edge  63  of the housing ribs  62 . The valve member  52  therefore rotates with respect to the actuating means  54  and housing  50  again. The rotation is stopped when the fins  86  enter the deeper channels  64  (also shown in  FIG. 19 ), at which point the valve  52  is permitted to return fully to its closed position where the O-ring  98  (not shown) engages the valve seat  50 . 1  to seal of the air path. The actuating means  54  therefore is also returned to its fully extended position. 
         [0240]    In the above description, the valve member  52  is described as having external fins  86  so as to cooperate with the internal channels  64  and  64 A of the housing  50 . However the invention will work with a housing that has internal fins which cooperate with external grooves or channels provided on the valve member. 
         [0241]    The valve member  52  and actuating means  54  can be supported by a body which includes a housing, or by any other body which includes appropriate structure to support the valve member  52  or the actuating means  54 . 
         [0242]    Modifications and improvements to the invention will be readily apparent to those skilled in the art. Such modifications and improvements are intended to be within the scope of this invention. 
         [0243]    Where ever it is used, the word “comprising” is to be understood in its “open” sense, that is, in the sense of “including”, and thus not limited to its “closed” sense, that is the sense of “consisting only of”. A corresponding meaning is to be attributed to the corresponding words “comprise”, “comprised” and “comprises” where they appear. 
         [0244]    It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text. All of these different combinations constitute various alternative aspects of the invention. 
         [0245]    While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not restrictive, and all modifications which would be obvious to those skilled in the art are therefore intended to be embraced therein.