Patent Publication Number: US-2020289308-A1

Title: An ostomy appliance

Description:
BACKGROUND 
     The invention relates to ostomy appliances. In particular, but not exclusively, the invention relates to closed ostomy appliances. 
     Ostomy appliances are well known. When an ostomy appliance becomes fuller it tends to start to bulge outwardly. Such outward bulging is unsightly, which may cause a user embarrassment. Also, the collection of waste in the bottom of the appliance can cause a user discomfort as it tends to  pull  at the top of a wafer which connects the appliance to a user. This can lead to the wafer detaching, which is clearly undesirable. 
     The present invention seeks to address these problems. 
     According to a first aspect of the invention we provide an ostomy appliance for receiving waste including:
         first and second walls connected to each other at or near their peripheries, the first wall having a stoma-receiving opening;   a waste collecting cavity defined between the first and second walls;   a first weld portion positioned to one side of the appliance and which connects the first and second walls together, which first weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance; and   a second weld portion positioned on an opposite side of the appliance to the first weld portion and which connects the first and second walls together, which second weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance.       

     Further features of the first aspect of the invention are set forth in the claims appended hereto. 
     The first and/or second weld portion may be connected to the peripheral connection of the first and second walls. 
     The first and/or second weld portion may be an extension or continuation of the peripheral connection of the first and second walls. 
     The first and/or second weld portion may be generally arcuate or a portion thereof may be generally arcuate. 
     The first and/or second weld portion may be generally curvilinear. 
     The first and/or second weld portion may be generally elongate. 
     An end of the first and/or second weld portion remote from the periphery of the appliance may be curved or rounded. 
     The ostomy appliance may include a plurality of said first weld portions and a plurality of said second weld portions. 
     The ostomy appliance may include upper and lower first weld portions one positioned above the other, and upper and lower second weld portions one positioned above the other. 
     The upper first weld portion may be a different shape from a lower first weld portion, and the upper second weld portion may be a different shape from a lower second weld portion. 
     The upper first weld portion may be smaller in area than a lower first weld portion, and the upper second weld portion may be smaller in area than a lower second weld portion. 
     The first weld portion may be elongate and have an axis B which extends lengthways thereof substantially midway therethrough, said axis B being inclined at an angle α to an axis C which extends along the peripheral connection of the first and second walls to each other. 
     Angle α may be less than 90°. 
     The ostomy appliance may include a further first weld portion positioned closer to a bottom of the appliance that the first weld portion, wherein the further first weld portion may be elongate and have an axis D which extends lengthways thereof substantially midway therethrough, said axis D being inclined at an angle θ to an axis E which extends along the peripheral connection of the first and second walls to each other. 
     Angle θ may be less than 90°. 
     Angle θ may be greater than angle α. 
     The second weld portion may be elongate and have an axis B which extends lengthways thereof substantially midway therethrough, said axis B being inclined at an angle α to an axis C which extends along the peripheral connection of the first and second walls to each other. 
     Angle α may be less than 90°. 
     The ostomy appliance may include a further second weld portion positioned closer to a bottom of the appliance that the second weld portion, wherein the further second weld portion may be elongate and have an axis D which extends lengthways thereof substantially midway therethrough, said axis D being inclined at an angle θ to an axis E which extends along the peripheral connection of the first and second walls to each other. 
     Angle θ may be less than 90°. 
     Angle θ may be greater than angle α. 
     The first and/or second weld portion may taper, i.e. narrow in width, as it extends away from the periphery of the appliance and downwardly towards the bottom of the appliance. 
     According to a second aspect of the invention we provide an ostomy appliance for receiving waste including:
         first and second walls connected to each other at or near their peripheries, the first wall having a stoma-receiving opening; and   a waste collecting cavity defined between the first and second walls;   wherein a midline M extends generally vertically between a top and a bottom of the ostomy appliance;   wherein the ostomy appliance further includes:   a first weld portion positioned to one side of the appliance and which connects the first and second walls together, which first weld portion extends away from a periphery of the appliance and downwardly towards the bottom of the appliance;   wherein the first weld portion includes:
           a top edge; and   a bottom edge; and   wherein the bottom edge is inclined at an angle to the midline M; and   
           a second weld portion positioned on an opposite side of the appliance to the first weld portion and which connects the first and second walls together, which second weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance;   wherein the second weld portion includes:
           a top edge; and   a bottom edge; and   wherein the bottom edge is inclined at an angle to the midline M.   
               

     The second aspect of the invention may include one or more or all of the features of the first aspect of the invention. 
     According to a third aspect of the invention we provide an ostomy appliance for receiving waste including:
         first and second walls connected to each other at or near their peripheries, the first wall having a stoma-receiving opening;   a waste collecting cavity defined between the first and second walls;   a first weld portion positioned to one side of the ostomy appliance and which connects the first and second walls together, which first weld portion extends away from a periphery of the ostomy appliance; and   a second weld portion positioned directly opposite the first weld portion on an opposite side of the ostomy appliance and which connects the first and second walls together, which second weld portion extends away from a periphery of the ostomy appliance;   wherein the first and second weld portions are positioned substantially midway between a top and a bottom of the waste collecting cavity.       

     The first weld portion may extend downwardly towards a bottom of the appliance and/or the second weld portion may extend downwardly towards a bottom of the appliance. 
     The third aspect of the invention may include one or more or all of the features of the first aspect and/or the second aspect of the invention. 
     According to a fourth aspect of the invention we provide an ostomy appliance for receiving waste including:
         first and second walls connected to each other at or near their peripheries, the first wall having a stoma-receiving opening;   a waste collecting cavity defined between the first and second walls;   a first weld portion positioned to one side of the appliance and which connects the first and second walls together, which first weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance; wherein the first weld portion includes:
           a top edge; and   a bottom edge;   
           wherein the top edge and bottom edge are generally parallel and are connected by a curved end; and   a second weld portion positioned on an opposite side of the appliance to the first weld portion and which connects the first and second walls together, which second weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance; wherein the second weld portion includes:
           a top edge; and   a bottom edge;   
           wherein the top edge and bottom edge generally parallel and are connected by a curved end.       

     The fourth aspect of the invention may include one or more or all of the features of any one of the first to third aspects the invention. 
     According to a fifth aspect of the invention we provide an ostomy appliance for receiving waste including:
         first and second walls connected to each other at or near their peripheries, the first wall having a stoma-receiving opening;   a waste collecting cavity defined between the first and second walls;   a first weld portion positioned to one side of the appliance and which connects the first and second walls together, which first weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance;   a second weld portion positioned on an opposite side of the appliance to the first weld portion and which connects the first and second walls together, which second weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance;   a third weld portion positioned to one side of the appliance above the first weld portion and which connects the first and second walls together, which third weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance; and a fourth weld portion positioned on an opposite side of the appliance to the third weld portion and which connects the first and second walls together, which fourth weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance.   The fifth aspect of the invention may include one or more or all of the features of any one of the first to fourth aspects the invention.       

     According to a sixth aspect of the invention we provide a drainable ostomy appliance for receiving waste including:
         first and second walls connected to each other at or near their peripheries, the first wall having a stoma-receiving opening;   a waste collecting cavity defined between the first and second walls;   an outlet which extends away from the stoma-receiving opening, the outlet having a width W and terminating at an opening;   a first weld portion positioned to one side of the appliance and which connects the first and second walls together, which first weld portion extends away from a periphery of the appliance and terminates in a free end; and   a second weld portion positioned on an opposite side of the appliance to the first weld portion and which connects the first and second walls together, which second weld portion extends away from a periphery of the appliance and terminates in a free end;   wherein the distance between the free ends of the first and second welds is greater than the width of the outlet.       

     The sixth aspect of the invention may include one or more or all of the features of any one of the first to fifth aspects the invention. 
     According to a seventh aspect of the invention we provide a drainable ostomy appliance for receiving waste including:
         first and second walls connected to each other at or near their peripheries, the first wall having a stoma-receiving opening;   a waste collecting cavity defined between the first and second walls;   an outlet which extends away from the stoma-receiving opening, the outlet having a width and terminating at an opening;   a first weld portion positioned to one side of the appliance and which connects the first and second walls together, which first weld portion extends away from a periphery of the appliance; wherein the first weld portion includes:
           a top edge; and   a bottom edge;   
           wherein the top edge and bottom edge are generally parallel and are connected by a curved end; and   a second weld portion positioned on an opposite side of the appliance to the first weld portion and which connects the first and second walls together, which second weld portion extends away from a periphery of the appliance; wherein the second weld portion includes:
           a top edge; and   a bottom edge;   
           wherein the top edge and bottom edge are generally parallel and are connected by a curved end.       

     The seventh aspect of the invention may include one or more or all of the features of any one of the first to sixth aspects the invention. 
     According to an eighth aspect of the invention we provide a colostomy appliance for receiving waste including:
         first and second walls connected to each other at or near their peripheries, the first wall being provided with a stoma-receiving opening;   a flange or connection member positioned around the stoma-receiving opening;   a waste collecting cavity defined between the first and second walls;   a first weld portion positioned to one side of the appliance below the stoma receiving opening and which connects the first and second walls together, which first weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance; and   a second weld portion positioned on an opposite side of the appliance to the first weld portion below the stoma-receiving opening and which connects the first and second walls together, which second weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance.       

     The eighth aspect of the invention may include one or more or all of the features of any one of the first to seventh aspects the invention. 
     According to a ninth aspect of the invention we provide a colostomy or ileostomy appliance for receiving waste including:
         first and second walls connected to each other at or near their peripheries, the first wall provided with a stoma-receiving opening;   a flange or connection member positioned around the stoma-receiving opening;   a waste collecting cavity defined between the first and second walls;   a first weld portion positioned to one side of the appliance and which connects the first and second walls together, which first weld portion extends away from a periphery of the appliance and terminates in a free end; and   a second weld portion positioned on an opposite side of the appliance to the first weld portion and which connects the first and second walls together, which second weld portion extends away from a periphery of the appliance and terminates in a free end;   wherein waste is permitted, in use, to pass from the stoma receiving opening directly downwardly to a bottom of the waste collecting cavity between the free ends of the first and second weld portions.       

     The ninth aspect of the invention may include one or more or all of the features of any one of the first to eighth aspects the invention. 
     According to a tenth aspect of the invention we provide a colostomy appliance for receiving waste including:
         first and second walls connected to each other at or near their peripheries, the first wall provided with a stoma-receiving opening;   a flange or connection member positioned around the stoma-receiving opening;   a waste collecting cavity defined between the first and second walls;   a first weld portion positioned to one side of the appliance and which connects the first and second walls together, which first weld portion extends away from a periphery of the appliance and terminates in a free end which is positioned at a distance X 1  or X 2  from the periphery of the appliance; and   a second weld portion positioned on an opposite side of the appliance to the first weld portion and which connects the first and second walls together, which second weld portion extends away from a periphery of the appliance and terminates in a free end which is positioned at a distance Y 1  or Y 2  from the periphery of the appliance;   wherein the free end of the first weld portion is spaced from the free end of the second weld portion by a distance D 1  or D 2 ;   wherein a sum of the distances X 1  and Y 1 , or X 2  and Y 2  is less than the second distance, D 1  or D 2 .       

     The tenth aspect of the invention may include one or more or all of the features of any one of the first to ninth aspects the invention. 
     According to an eleventh aspect of the invention we provide a colostomy appliance for receiving waste including:
         first and second walls connected to each other at or near their peripheries, the first wall provided with a stoma-receiving opening;   a flange or connection member positioned around the stoma-receiving opening;   a waste collecting cavity defined between the first and second walls;   a first weld portion positioned below the stoma receiving opening and to one side of the appliance and which connects the first and second walls together, which first weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance; and
 
a second weld portion positioned directly opposite the first weld portion on an opposite side of the appliance to the first weld portion and which connects the first and second walls together, which second weld portion extends away from a periphery of the appliance and downwardly towards a bottom of the appliance.
       

     The eleventh aspect of the invention may include one or more or all of the features of any one of the first to tenth aspects the invention. 
    
    
     
       Embodiments of the invention will now be described by way of example only with reference to the accompanying drawing, of which: 
         FIG. 1  is a front view of an ostomy appliance in accordance with the present invention; 
         FIG. 2  is a cross-sectional view of the ostomy appliance of  FIG. 1  along the line A-A; 
         FIG. 3  is a close up view of a first weld portion of the appliance of  FIG. 1 ; 
         FIG. 4  is a close up view of a further first weld portion of the appliance of  FIG. 1 ; 
         FIG. 5  is a further front view of the ostomy appliance of  FIG. 1 ; 
         FIG. 6  is a further front view of the ostomy appliance of  FIG. 1 ; and 
         FIG. 7  is a further front view of the ostomy appliance of  FIG. 1 . 
     
    
    
     Referring to the figures, there is shown an ostomy appliance  10  having a top and a bottom generally indicated at  11  and  13 , respectively. The ostomy appliance  10  has first and second walls  12 ,  14  connected to each other at or near their peripheries  15 . In the present example the first and second walls  12 ,  14  are welded to each other. However, they could, alternatively, be adhered to each other or connected using any other suitable means known in the art. 
     Whilst the appliance shown is a closed colostomy appliance, it could be a drainable ostomy appliance with an outlet  50  such as the one shown in dotted lines in  FIG. 1 . The outlet  50  may take any suitable form and usually includes a closure mechanism for selective closing/opening the appliance for draining the contents. The outlet  50  may also have a width W, as shown in  FIG. 5 . 
     The first wall  12  includes a stoma-receiving opening  16 , through which a stoma is received. A connection member or flange  17  is connected to the first wall  12  for attaching the appliance  10  to a user. The connection member  17  used may be, for instance, a hydrocolloid wafer for securing the appliance  10  to the skin of a user around their stoma. Such a configuration is referred to as a one-piece ostomy appliance. Alternatively, the connection member may be for attaching the appliance  10  to a flange for attaching the appliance to a user. Such a device is referred to as a two-piece ostomy appliance. The connection member is positioned around the stoma-receiving opening  16  to ensure a secure fitment of the appliance  10  to a user. 
     A waste collecting cavity  18  is defined between the first and second walls  12 ,  14 . The first and second walls  12 ,  14  may be covered by comfort layers though this is not essential. The appliance  10  may also have a filter  9  positioned over a gas vent  8  in either the first wall  12  or second wall  14 . 
     Advantageously, the appliance  10  includes additional weld portions (to the peripheral weld which connects the first and second walls  12 ,  14  to each other). In the present embodiment, the appliance includes four such additional weld portions D two on each side of the appliance. There are weld portions  20 ,  28  on the left side of the appliance  10  and weld portions  22 ,  30  on the right side of the appliance (as viewed in  FIG. 1 ). The weld portions  20  and  22  are positioned directly opposite each other, and the weld portions  28 ,  30  are positioned directly opposite each other. The weld portion  20  is positioned above the weld portion  28 , whilst the weld portion  22  is positioned above the weld portion  30 . 
     Each weld portion  20 ,  22 ,  28 ,  30  extends away from the periphery  15  of the appliance  10  and downwardly towards the bottom of the appliance  10 . The weld portions  20  and  22  are positioned at least partly below the stoma-receiving opening  16 . 
     The ostomy appliance is generally symmetrical about the midline M which extends generally vertically between the top  11  and bottom  13  of the ostomy appliance  10 , although in other embodiments it need not be. 
     In this embodiment, and as shown in  FIG. 5 , the weld portions  20 ,  22  are positioned completely below the stoma-receiving opening  16 , and are positioned substantially midway between the top  11  and the bottom  13  of the appliance  10 . In particular the weld portions  20 ,  22  are halfway between the top  11  and the bottom  13  of the appliance  10 . As will be appreciated from  FIG. 5 , the weld portion  22  is a mirror image of the weld portion  20  about the midline M. 
     As mentioned above, the weld portions  28 ,  30  are positioned below the weld portions  20 ,  22 . In particular, the weld portions  28 ,  30  are positioned substantially midway between the weld portions  20 ,  22  and the bottom  13  of the appliance  10 . In other words, the weld portions  28 ,  30  are positioned vertically about three quarters of a total length of the appliance  10  away from a top  11  of the appliance  10  and are positioned vertically about one quarter of a total length of the appliance  10  (not including the outlet  50 ) away from a bottom  13  of the appliance  10 . Again, the weld portion  30  is positioned directly opposite the weld portion  28 . In particular, the weld portion  30  is a mirror image of the weld portion  28  about the midline M. 
     The weld portions  20 ,  22 ,  28 ,  30  are highly advantageous in preventing bulging of the appliance  10  during use when it contains waster. The weld portions  20 ,  22 ,  28 ,  30  ensure that the force acting on the appliance as a result of the waste is distributed relatively evenly along the length of the appliance  10 . This helps to prevent the appliance  10  from  pulling  on the top of the connection member  17 . 
     Each weld portion  20 ,  22 ,  28 ,  30  connects the first and second walls  12 ,  14  to each other and in this embodiment, each weld portion is a continuation of the peripheral weld which connects the first and second walls to each other. Thus, the weld portions  20 ,  22 ,  28 ,  30  are each connected to the peripheral weld  15  and act as an extension or continuation of the peripheral weld  15 . This is advantageous because the weld portions  20 ,  22 ,  28 ,  30  may then be formed in the same process which forms the peripheral weld  15  between the first and second walls  12 ,  14 . In alternative embodiments, the weld portions  20 ,  22 ,  28 ,  30  may not be connected to the peripheral connection  15  between the first and second walls  12 ,  14 , e.g. there may be a space between where the first and second walls  12 ,  14  are not connected to each other. 
     The weld portions  20 ,  22 ,  28 ,  30  are each elongate with upper edges which are generally arcuate. The weld portions  20 ,  22 ,  28 ,  30  could be curvilinear. An end of the weld portions  20 ,  22 ,  28 ,  30  remote from the periphery  15  of the appliance is curved or rounded. 
     In particular, and as can be seen in  FIGS. 3 and 4 , the weld portion  22 ,  30  has a top edge  22   b ,  30   b  and a bottom edge  22   c ,  30   c  which are connected by a curved free end  22   a ,  30   a . A portion of the top edge  22   b ,  30   b  is parallel with a portion of the bottom edge  22   c ,  30   c . A portion of the top edge  22   b ,  30   b , near the periphery  15 , diverges away from the bottom edge  22   c ,  30   c . A portion of the bottom edge  22   c ,  30   c , again near the periphery  15 , diverges away from the top edge  22   b ,  30   b . In the present embodiment the portions of the top and bottom edges  22   b ,  30   b ,  22   c ,  30   c  which diverge are curved, but in other alternative embodiments they may be linear. Again, weld portion  20 ,  28  is a mirror image of weld portion  22 ,  30 , and so is substantially the same. 
     The weld portion  20  terminates in a free end  20   a  which is positioned a distance X 1  away from the periphery  15  of the appliance  10 . The weld portion  22  also terminates in a free end  22   a  which is positioned a distance Y 1  away from the periphery  15  of the ostomy appliance  10 . The free end  20   a  of the first weld portion is spaced from the free end  22   a  of the second weld portion by a distance D 1 , as shown in  FIG. 5 . A sum of the distances X 1  and Y 1  is less than the distance D 1 . 
     The weld portion  28  terminates in a free end  28   a  which is positioned a distance X 2  away from the periphery  15  of the appliance  10 . The weld portion  30  also terminates in a free end  30   a  which is positioned a distance Y 2  away from the periphery  15  of the ostomy appliance  10 . The free end  28   a  of the first weld portion is spaced from the free end  30   a  of the second weld portion by a second distance D 2 . A sum of the distances X 2  and Y 2  is less than the distance D 2 . 
     In some embodiments the ostomy appliance  10  is a drainable ostomy appliance and has an outlet  50  having a width W, as explained previously. In those embodiments the distance D 1  is greater than the width W of the outlet  50 . The distance D 2  is also greater than the width W of the outlet  50 . 
     In use, waste is permitted to pass from the stoma-receiving opening  16  between the free ends  20   a ,  22   a ,  28   a ,  30   a  of the weld portions directly downwardly to a bottom of the waste collecting cavity  18 , and in the case of a drainable appliance, directly to the outlet  50 . 
       FIG. 7  shows the angle φ 1 , φ 2 , φ 3 , φ 4  at which the bottom edge of the weld portion  20   c ,  22   c ,  28   c ,  30   c  is inclined with respect to the midline M. 
     In the embodiment shown the angles φ 1  and φ 2  are the same. However, in other alternative embodiments the angle φ 1  may be greater than φ 2 , or the angle φ 2  may be greater than φ 1  without departing from the scope of the present invention. 
     The angles φ 3  and φ 4  are also the same. However, in other alternative embodiments the angle φ 3  may be greater than φ 4 , or the angle φ 4  may be greater than φ 3 . 
     It can also be seen that the angle φ 1  is greater than the angle φ 3 . However, in other alternative embodiments the angle φ 1  may be the same as the angle φ 3 , or the angle φ 3  may be greater than φ 1 . 
     Also, the angle φ 2  is greater than the angle φ 4 . However, in other alternative embodiments the angle φ 2  may be the same as φ 4 , or the angle φ 4  may be greater than φ 1   2 . 
       FIG. 6  shows the angle β 1 , β 2 , β 3 , β 4  at which the top edge of the weld portion  20   b ,  22   b ,  28   b ,  30   b  is inclined with respect to the midline M. 
     In the embodiment shown the angles β 1  and β 2  are the same. However, in other alternative embodiments the angle β 1  may be greater than β 2 , or the angle β 2  may be greater than β 1  without departing from the scope of the present invention. 
     The angles β 3  and β 4  are also the same. However, in other alternative embodiments the angle β 3  may be greater than β 4 , or the angle β 4  may be greater than β 3 . 
     It can also be seen that the angle β 1  is greater than the angle β 3 . However, in other alternative embodiments the angle β 1  may be the same as the angle β 3 , or the angle β 3  may be greater than β 1 . 
     Also, the angle β 2  is greater than the angle β 4 . However, in other alternative embodiments the angle β 2  may be the same as β 4 , or the angle β 4  may be greater than β 2 . 
     In the present embodiment the angle β 1  is the same as the angle φ 1 . However, in other embodiments the angle β 1  may be greater than the angle φ 1 . In further envisaged embodiments the angle φ 1  may be greater than the angle β 1  without departing from the scope of the present invention. 
     In the present embodiment the angle β 2  is the same as the angle φ 2 . However, in other embodiments the angle β 2  may be greater than the angle φ 2 . In further envisaged embodiments the angle φ 2  may be greater than the angle β 2  without departing from the scope of the present invention. 
     In the present embodiment the angle β 3  is greater than the angle φ 3 . However, in other embodiments the angle β 3  may be the same as the angle φ 3 . In further envisaged embodiments the angle φ 3  may be greater than the angle β 3  without departing from the scope of the present invention. 
     In the present embodiment the angle β 4  is greater than the angle φ 2 . However, in other embodiments the angle β 4  may be the same as the angle (pa. In further envisaged embodiments the angle φ 4  may be greater than the angle β 4  without departing from the scope of the present invention. 
     As can be seen from  FIGS. 3 and 4 , the weld portions  20  and  22  are a different shape from the weld portions  28  and  30 . It will also be seen from those figures that the weld portions  20  and  22  are smaller in area (i.e. surface area of the weld) than the area of the weld portions  28  and  30 . Their shapes and area size have been configured to provide improved resistance to sagging of the appliance  10  during use. 
     As shown in  FIG. 3 , the weld portion  22  is elongate and has an axis B which extends lengthways thereof substantially midway therethrough. The axis B is inclined at an angle α (which is preferably less than 90°) to an axis C which extends along the peripheral weld  15 . It will be noted that the weld portion  20  is similarly configured to the weld portion  22 . 
     As shown in  FIG. 4 , the weld portion  30  is also elongate, but it will also be seen that the weld portion  30  tapers, i.e. narrows in width, as it extends away from the peripheral weld  15  downwardly towards the bottom of the appliance  10 . The weld portion  30  has an axis D which extends lengthways thereof substantially midway therethrough. The axis D is inclined at an angle θ (which is preferably less than 90°) to an axis E which extends along the peripheral weld  15 . It will be noted that the weld portion  28  is similarly configured to the weld portion  30 . 
     Whilst various angles of θ and α fall within the scope of the present invention, further advantages of the operation of the appliance have been found where θ is greater than α. In other words, where the appliance has two or more weld portions at each side, the lower weld portions are inclined at a greater angle to the axis which extends along the peripheral weld  15  than the upper weld portions. 
     In envisaged embodiments, the appliance  10  may only have one weld portion at each side thereof. In envisaged embodiments, the appliance  10  may have three or more weld portions at each side thereof. In envisaged embodiments, the appliance  10  may an odd number of weld portions at one side of the appliance and an even number of weld portions at the opposite side of the appliance. 
     When used in this specification and claims, the terms “comprises” and “comprising” and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components. 
     The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.