WO2008127108A1

WO2008127108A1 - Method of manufacturing an inflatable balloon and an inflatable balloon

Info

Publication number: WO2008127108A1
Application number: PCT/NL2008/050217
Authority: WO
Inventors: Cornelis Born
Original assignee: Stokvis, Paulus
Priority date: 2007-04-17
Filing date: 2008-04-16
Publication date: 2008-10-23
Also published as: NL2000600C2

Abstract

An inflatable balloon comprises an inflatable body and a filling neck projecting outwardly from the inflatable body and including a filling opening which is disposed at a distance of the inflatable body. The balloon is made of latex and provided with a self-closing valve, which is formed of at least two opposite elastic sheet members which form a closed channel in peripheral direction. The filling opening communicates with the inflatable body through this channel. The sheet members are formed such that they seal the channel at least when the pressure at the side of the valve where the inflatable body is disposed is higher than at the side of the valve where the filling opening is disposed. There are several methods of manufacturing the inflatable balloon.

Description

Method of manufacturing an inflatable balloon and an inflatable balloon

[0001] The present invention relates to a method of manufacturing an inflatable balloon which is provided with a self-closing valve in its final condition, wherein the self- closing valve is inserted into the balloon, which, in its initial condition, comprises an inflatable body and a tube communicating therewith, which tube is made of a sheet material and projects outwardly from the inflatable body. [0002] Such a method is disclosed in the international patent application WO 2006/081187. In the known method a valve member is arranged in the filling opening at the end of the tube of the balloon. The valve member is arranged such that air which is blown through the entrance can flow into the inflatable body but not in opposite direction. As a consequence the balloon does not deflate automatically after inflating it. The valve member which has to be assembled with the balloon is relatively complex, which makes this solution for manufacturing an inflatable balloon including a self- closing valve relatively expensive. [0003] The object of the invention is to provide a method with which a balloon including a self-closing valve can be manufactured in a less expensive manner.

[0004] This object is achieved with the method according to the invention which is characterized in that the valve is arranged by displacing a distal portion of the tube which distal portion is spaced from the inflatable body in the initial condition, in the direction of the inflatable body through a proximal portion of the tube which proximal portion is adjacent to the inflatable body so as to form a channel by the distal portion, through which channel the inflatable body communicates with the environment of the balloon, until still a portion of the tube remains outside the inflatable body, such that the remaining portion of the tube forms a filling neck for inflating the balloon, and after which the proximal and distal portions are fixed with respect to each other in the axial direction of the filling neck so as to avoid a displacement of the distal portion with respect to the inflatable body outwardly in an inflated condition thereof. [0005] Due to these characteristics a balloon can be manufactured of which the original tube in the initial condition of the balloon is deformed such that a self-closing valve arises in the final condition of the balloon. The self- closing valve is formed by the distal portion of the tube which is displaced through the tube which distal portion is disposed at a distance of the inflatable body in the initial condition. The resulting channel is enveloped by the sheet material of the tube and is pressed to a closed condition as soon as the pressure at the side of the inflatable body is higher than at the opposite side of the channel . The method according to the invention avoids that the thus formed self- closing valve can be blown outwardly because of the fixation of the proximal and distal portions of the tube with respect to each other in axial direction.

[0006] Since a portion of the original tube is displaced with respect to another portion thereof in the direction of the inflatable body, the remaining portion forming the filling neck will be shorter than the tube in the initial condition. This means that for a sufficiently long filling neck the original tube is preferably longer than that of standard playing balloons, for example, which are currently available . [0007] The advantage of this method is that a balloon including a self-closing valve is obtained in a simple manner. This method also provides the possibility to make the entire balloon of the same material. Besides, it can be added to an existing manufacturing process of balloons, such that a relatively cheap method of manufacturing is obtained. [0008] The sheet material is a thin elastic material, such as latex or the like. Since the entire balloon, so including the valve, is made of such a material, the balloons can be packaged in a relatively compact way. The initial condition of the balloon is the condition in which the balloon is still not provided with a valve, for example the condition of the balloon in case of standard playing balloons which are not inflated yet. In the final condition the balloon is provided with a self-closing valve, wherein the balloon is inflatable through the filling neck, similar to a current standard latex balloon. In practice the outer side of the balloon may look like similar to a standard latex balloon.

[0009] In a practical embodiment the distal portion is a loose end portion of the tube in the initial condition of the balloon. This means, for example, that the loose end portion can be displaced inner side out through the proximal portion in the direction of the inflatable body, such that the resulting filling neck is in any case partly double walled, because there the distal portion is disposed within the proximal portion

[0010] In an alternative method, prior to performing the displacement of the loose end portion in the direction of the inflatable body, an outer wall of at least a part of the loose end portion may be arranged at two opposite locations inwardly of the tube, after which in any case a force on the tube is applied in a direction substantially perpendicular to that of the displacement of the opposite locations, so as to arrange a sharp crease at the locations of the tube which are displaced inwardly. The sharp creases thus formed inwardly have the advantage, that when the end portion is displaced in the direction of the inflatable body, the cross section of the channel has an advantageous shape. In the resulting shape of the final condition the distal portion has sharp creases at two opposite locations, such that the sheet material disposed between the creases tends to lie cloose to each other or on each other in a rest condition. This results in an advantageous closing function of the valve. [0011] According to another alternative method at least a part of the end portion remains outside the inflatable body in the final condition of a balloon in which the distal portion lies between the proximal portion and an end portion of the tube in the initial condition. This means that the distal portion and the end portion do not turn inside out when they are displaced in the direction of the inflatable body. This provides the possibility to facilitate the manufacturing of an embodiment in which at least a part of the distal portion is provided with sharp creases at two opposite side edges of the tube, because the creases can be simply arranged from outside of the tube by means of heat or pressure on the tube, for example.

[0012] According to another alternative method the balloon is turned inside out in the initial condition, after which at least a part of the end portion of the tube is treated such that sharp creases are formed at two opposite locations of the tube, after which the balloon is again turned inside out, prior to displacing the loose end portion of the tube in the direction of the inflatable body. In this manner the desired sharp creases can be applied simply, without relatively complex displacements of opposite locations of the outer wall of the tube in inward direction thereof. Of course, it is also possible that the balloon is not folded inside out for applying the crease at first, but applying the sharp creases at the tube directly from outside of the tube and folding the balloon inside out after that, which means that the original inner side of the balloon in the initial condition becomes the outer side in the final condition. However, this may be undesired if the inner side in the initial condition has a surface which is less beautiful than the outer side thereof. [0013] The sharp creases may be formed by applying pressure from outside onto the tube and increasing the temperature at least at the locations where the creases are intended. This appears to be an effective measure for de-forming the material permanently, certainly in case of balloons made of latex.

[0014] According to still an other alternative method a channel-shaped member which is made of sheet material is attached to the tube such that the channel-shaped member communicates with the tube, after which a distal portion of the channel-shaped member which is located at a distance of the tube is displaced through the tube in the direction of the inflatable body. In this case it is not necessary that the balloon is turned inside out entirely, but the channel- shaped member may be provided with inwardly turned sharp creases, such as described herein before. The channel-shaped member can be adhered, welded or attached to the tube in an other way, for example.

[0015] Prior to attaching the channel-shaped member to the tube an end portion of the tube in an initial condition thereof can be displaced along the outer side of the tube in the direction of the inflatable body, such that a new end portion of the tube is formed at a distance of the inflatable body. The channel-shaped member is attached to the new end portion, after which the distal portion of the channel-shaped member is displaced in the direction of the inflatable body, and the end portion is returned along the outer side of the tube in the position of the initial condition. Due to this method a balloon is obtained, wherein the risk of the channel-shaped member being pressed outwardly from the inflatable body after inflating the inflatable body is small. [0016] Preferably the tube is tapered in the initial condition as seen from the inflatable body, because this facilitates the end portion being put through the proximal portion of the tube, and the end portion not being put under pressure in a final condition of the balloon by the enveloping proximal portion, causing a possible insufficient closing function of the distal portion. [0017] In another alternative method the valve which is a channel-shaped member made of sheet material, is arranged through the tube in the direction of the inflatable body, after which it is fixed to the tube. In this case the loose prefabricated valve is displaced through the tube at first and then fixed to the tube. The advantage of this is that the valve can be provided with creases, separate from the balloon in which the valve needs to be introduced. [0018] This method can be applied specifically by clamping the channel-shaped member around an assembly pin prior to inserting the channel-shaped member into the tube, and then arranging the tube of the balloon about the channel-shaped member in the initial condition, and then fixing the tube and the channel-shaped member to each outer and removing the thus formed balloon from the assembly pin. This appears to be a very simple but effective way of manufacturing. The creases arranged in the channel-shaped member appear to be maintained when applying latex as the elastic sheet material after arranging it about the assembly pin. [0019] The method is facilitated further by applying a sliding means to the outer side of the channel-shaped member prior to applying the tube thereabout.

[0020] A further alternative method of manufacturing an inflatable balloon which is provided with a self-closing valve, which is a channel-shaped member made of sheet material, is characterized in that the channel-shaped member is releasably connected to a balloon-shaped mold, after which the mold including at least a portion of the channel-shaped member connected thereto are submerged by means of a dipping process in liquid latex and dried, after which the thus formed balloon including the valve is removed from the mold, wherein at least a part of the submerged portion of the channel-shaped member is arranged such that it adheres to the liquid latex. In this method the application of the channel- shaped member is integrated in an existing manufacturing process of latex balloons. Latex balloons are manufactured by submerging a mold which has a shape of an empty balloon in liquid latex through a dipping process and drying afterwards. In the method according to the invention at least a portion of the pre-manufactured channel-shaped member is submerged, as well. As a result the balloon formed of liquid latex is connected to the channel-shaped member. If the channel-shaped member is made of latex it will adhere to the liquid latex automatically and the valve and the balloon will be integrated after drying. [0021] More specifically the channel-shaped member can be applied about a portion of the mold prior to submerging the mold including the channel-shaped member which is applied thereabout in liquid latex. This portion of the mold is a portion that corresponds to the filling neck to be formed, for example, such that the channel-shaped member will be fixed to the filling neck in a final condition. [0022] In order to avoid that the channel-shaped member will entirely adhere to the portion of the balloon to be formed, a portion of the outer side of the channel-shaped member is provided with an anti-adhesive layer before the dipping process.

[0023] It is also possible to insert a part of the channel- shaped member into a cavity of the mold before the channel- shaped member is connected to the mold so as to protect the portion which is inserted into the cavity against the liquid latex during the dipping process. As a result this part does not adhere to the remainder of the balloon to be formed. [0024] In a preferred embodiment of the mold the cavity is at least partly formed by a tubular portion of the mold, wherein an end portion of the channel-shaped member is folded outwardly back about an end portion of the tubular portion of the mold onto an outer side of the tubular portion of the mold so as to connect the channel-shaped member with the mold, wherein at least the end portion contacts the liquid latex during the dipping process. In practice this connection of the channel-shaped member and the mold is robust due to the elasticity of the sheet material.

[0025] The invention is also related to an inflatable balloon which comprises an inflatable body and a filling neck projecting outwardly from the inflatable body which filling neck includes a filling opening which is disposed at a distance of the inflatable body, which are made of latex, wherein the balloon is provided with a self-closing valve, and the valve is formed of at least two opposite elastic sheet members which form a channel which is closed in peripheral direction, through which channel the filling opening communicates with the inflatable body, wherein the sheet members are formed such, that they close the channel at least when the pressure at the side of the valve where the inflatable body is located is higher than at the side of the valve where the filling opening is located. Herein, latex means, that the material of which the inflatable body and the filling neck are made can be latex as well as alternative thin and elastic materials. The advantage of the balloon according to the invention is that it is not necessary to make a knot in the filling neck in order to maintain the balloon in its inflated condition. Due to knotting the material of the balloon appears to be sensitive to damage such that an inflated balloon deflates slowly. Besides, the balloon according to the invention provides the opportunity to be made of a single material, thus wherein the sheet members are also made of latex or a comparable material. Furthermore, the self-closing valve requires little room such that a relatively large number of this type of balloons fits in a small package.

[0026] The sheet members can be connected to the filling neck between the filling opening and the inflatable body. This is a more advantageous location than in the inflatable body, for example, because the deformation of the filling neck is relatively small during the inflation of the balloon. As a consequence, no high pressure in the valve and/or between the valve and the filling neck occurs. [0027] The sheet members may extend beyond a transfer portion of the filling neck toward the inflatable body. As a consequence, the risk of the valve being blown outwardly through the filling neck in case of an inflated inflatable body is minimized. The transfer portion can be defined by a cutting surface between the tube and a virtual envelope of the inflatable body. [0028] Preferably at least a portion of the channel includes two opposite side edges where the cross section of the channel forms an acute angle, such that in a rest condition the sheet members substantially lay on each other. As a consequence, an effective closing function of the valve is provided.

[0029] The sheet members may be formed of a single sheet, in which at least one sharp crease is arranged so as to form one of the side edges. The opposite side edge can also be folded, but could also be a welded or a glued connection. [0030] In an alternative embodiment at the channel the sheet members may at least partly be provided with an elastic rigidity in peripheral direction of the channel, such that the sheet members move from each other when they are pressed so as to facilitate deflation of an inflated balloon. Possibly, this effect can also be achieved by inserting a suitable object into the filling neck in the direction of the inflatable body in order to move the walls of the channel away from each other. [0031] Preferably, the inflatable body, the filling neck and the valve are made of a single sheet, because this allows a cheap manufacturing method. Such a balloon can be made according to the method as described hereinbefore. [0032] In another alternative embodiment of the inflatable balloon which comprises an inflatable body and a filling neck which projects outwardly from the inflatable body including a filling opening which is disposed at a distance of the inflatable body, wherein the balloon is provided with a self- closing valve and, the valve is formed of a closing member, which is freely movable within the inflatable body and has a larger size than a smallest cross-sectional area of the filling neck in an inflated condition of the balloon. The closing member has such a shape that in an inflated condition of the inflatable body it contacts a portion of an inner wall of the inflatable body at the filling neck such, that the closing member seals the inflatable body with respect to the environment of the balloon as a consequence of the pressure in the inflatable body on the closing member which is pressed against a portion of the inner wall of the inflatable body as a consequence thereof when the closing member is displaced in the direction of the filling neck. After inflating the balloon in this embodiment the user can displace the closing member in the direction of the filling neck by shaking the balloon, such that the closing member is hold against the inner wall of the inflatable body by the pressure applied on it. [0033] Preferably the closing member has a spherical shape, because then it is easy to displace along the inner wall of the inflatable body and the risk of damaging the inner wall of the inflatable body is minimized. Besides, there is no preferred side of the closing member which should be displaced in the direction of the filling neck.

[0034] It is noted that self-closing valves comprising opposite sheet members are known, but these are typically applied for balloons which are made of foil having a very limited elasticity and manufacturing of such balloons requires a complex manufacturing process.

[0035] The invention will be elucidated further hereinafter with reference to drawings, which show embodiments of the invention very schematically. [0036] Fig. Ia is a side view of an embodiment of an inflatable balloon according to the invention in an initial condition and Fig . Ib is a view along the line Ib-Ib in Fig .

Ia .

[0037] Fig. 2a is a longitudinal cross-sectional view of the balloon according to Fig. Ia in a final condition and Fig. 2b is a view along the line Hb-IIb in Fig. 2a.

[0038] Fig. 3a is a view similar to Fig. Ia of an alternative embodiment and Fig. 3b is a view along the line

HIb-IIIb in Fig. 3a.

[0039] Fig. 4a is a longitudinal cross-sectional view of the balloon according to Fig. 3a in a final condition and Fig. 4b is a view along the line IVb-IVb in Fig. 4a.

[0040] Fig. 5a is a view similar to Fig. Ia of another alternative embodiment and Fig. 5b is a view along the line

Vb-Vb in Fig. 5b. [0041] Fig. 6a is a longitudinal cross-sectional view of the balloon according to Fig. 5a in a final condition and Fig. 6b is a view along the line VIb-VIb in Fig. 6a.

[0042] Fig. 7 and 8 are views similar to Fig. 2a of alternative embodiments of the inflatable balloon. [0043] Fig. 9a-9c are side views and Fig. 9d is a longitudinal cross-sectional view of an alternative embodiment of an inflatable balloon according to the invention, wherein different steps of the method of manufacturing it are shown. [0044] Fig. 10a is a view similar to Fig. 3a of an alternative embodiment and Fig. 10b is a cross-sectional view along the line Xb-Xb in Fig. 10a.

[0045] Fig. 11a is a longitudinal cross-sectional view of the balloon according to Fig. 10a in a final condition and Fig. lib is a cross sectional view along the line XIb-XIb in

Fig. 11a.

[0046] Fig. 12a-12c are side views and partially perspective and cross-sectional views of an embodiment of a balloon, a channel-shaped member and an assembly pin, which show different steps according to an alternative manufacturing method. [0047] Fig. 13a-b are partially side and cross-sectional views of a mold and a valve, in which a manufacturing process of an embodiment of a balloon according to the invention are illustrated. [0048] Fig. 14a-b are views similar to Fig. 13a-b, in which the mold is shown in a partial cross-sectional view, and in which an alternative manufacturing process is illustrated, and Fig. 14c is a side view of the balloon, in which this is shown in the manufactured condition separated from the mold. [0049] Fig. 15 is a longitudinal cross-sectional view of an alternative embodiment of an inflatable balloon in inflated condition.

[0050] Fig. Ia shows a side view of an embodiment of an inflatable balloon 1 according to the invention in an initial condition. In this condition the balloon 1 comprises an inflatable body 2 and a tube 3 made of a sheet material and communicating therewith. The tube 3 projects outwardly from the inflatable body 2. The balloon 1 is provided with a transfer portion 4 between the inflatable body 2 and the tube 3. Within this transfer portion 4 the cross section of the balloon 1, as seen from the tube 3, increases. In practice, the transfer portion 4 forms the border between the inflatable body 2 and the tube 3, which border substantially forms the cutting edge between the tube 3 and a virtual envelope of the inflatable body 2.

[0051] In the embodiment as shown in Fig. Ia the balloon is made of latex. When latex is used herein, it means that the applied material is latex or an alternative material which shows similar characteristics, so a thin and elastic sheet material, as well.

[0052] Fig. 2a shows a longitudinal cross-sectional view of the balloon 1 according to the embodiment of Fig. Ia in a final condition. In this condition the balloon 1 is provided with a self-closing valve 5. The valve 5 is made by deforming a portion of the tube 3. This is achieved by displacing a distal portion of the tube 3, which is a loose end portion 6 in the embodiment of Fig. Ia, in the direction of the inflatable body 1. In the initial condition the loose end portion 6 is disposed at a distance of the inflatable body 2. [0053] In order to make the shape according to Fig. 2a, the end portion 6 is displaced through a proximal portion 7 of the tube 3 which is adjacent to the inflatable body 2. As a consequence of this displacement a channel 8 is formed with the distal portion 6. [0054] The inflatable body 2 communicates with the environment of the balloon 1 via the channel 8. In the final condition of the balloon 1 according to Fig. 2a a portion of the tube 3 still remains outside the inflatable body 2. This remaining portion of the tube 3 forms a filling neck 9 for inflating the balloon 1, such as this is present in conventional balloons. The inflatable body 2 can be inflated, for example, by introducing a gas via a filling opening 10 of the filling neck 9 through the channel 8 to the inflatable body 2. [0055] In this case the loose end portion 6 extends in the direction of the inflatable body 2 beyond the transfer portion 4 to the inflatable body 2. In the final condition the transfer portion 4 is disposed between the inflatable body 2 and the filling neck 9. [0056] Furthermore, in the embodiment as shown in Fig. 2a the proximal portion 7 and the end portion 6 are fixed with respect to each other in the axial direction of the filling neck 9. As a consequence of this, displacing the distal portion 6 outwardly with respect to the inflatable body 2 in inflated condition thereof is prevented. The fixation can be performed in several manners, for example by heat welding or gluing. The fixation is schematically illustrated in Fig. 2a using reference sign 12.

[0057] Fig. Ib shows that the cross section of the loose end portion 6 has a circular shape. In reality this shape mainly depends on the sheet material which is used. In practice, it may be such that in a rest condition the sheet material is disposed on each other. It can be seen in Fig. 2b that the loose end portion 6 of the tube 3 which is inserted inwardly through the proximal portion 7 also has a circular cross section. Similar to the initial condition, in practice, the shape can be different from the circular shape in the final condition.

[0058] When the balloon 1 is inflated the pressure in the inflatable body 2 will become higher than at the side of the filling opening 10. In this condition the channel 8 will be pressed to a closed condition due to the higher pressure on the outer side of the free portion of the end portion 6 as shown in Fig. 2a and be opened not before the condition in which the pressure during inflation at the side of the filling opening becomes higher at the side of the inflatable body 2.

[0059] The closing function of the valve 5 can be improved by forming the channel 8 such that in a rest condition opposite walls of at least a part of the end portion 6 of the tube 3 which is displaced inwardly, are disposed on each other. This is illustrated in the embodiment of Fig. 4a and 4b. In the final condition of the balloon 1 as shown in the figures the cross section of the end portion 6 is provided with opposite sharp creases 11. As a consequence of this the parts of the sheet material of the tube 3 which are disposed between the creases 11 are forced against each other or almost against each other in a rest condition. As soon as the pressure in the inflatable body 2 is higher than at the side of the filling opening 10 the channel 8 will be pressed to a closed condition more easily. [0060] Fig. 3a shows a side view of this embodiment after the following treatment has been performed from an initial condition as shown in Fig. Ia. Before performing the displacement of the loose end portion 6 in the direction of the inflatable body 2 an outer wall of at least a portion of the loose end portion 6 is put inwardly of the tube 3 at two opposite locations. When these locations are put on a predetermined distance of each other, in any case a force is applied on the tube 3 in a direction substantially perpendicular to that of the displacement of the opposite locations. As a consequence of this a sharp crease 11 which is facing inwardly of the tube 3 is arranged at the locations which are displaced inwardly of the tube 3. The result of this can be seen in Fig. 3b. When the loose end portion 6 is displaced inwardly, the portion including the creases 11 turns inside out and forms the shape as illustrated in Fig. 4b.

[0061] The embodiment of the balloon 1 as shown in Fig. 4a can also be obtained in another alternative way by turning the balloon 1 inside out in an initial condition as shown in Fig. Ia and then treating a part of the end portion 6 of the tube 3 such that sharp creases are formed at two opposite locations of the tube 3, for example by means of heat and pressure on the outer side of the tube 3. The part of the end portion 6 of the tube 3 that is treated in this way, has a cross section which is comparable to that of Fig. 4b. After that the balloon 1 is turned inside out to the original initial condition and the balloon appears as shown in Fig. 3a. When next the loose end portion 6 of the tube 3 is displaced in the direction of the inflatable body 2 through the proximal portion 7 the balloon 1 of Fig. 4a and 4b is obtained. Turning inside out of the balloon 1 can be facilitated, for example, by applying the end portion 6 of the balloon 1 in the initial condition as shown in Fig. Ia about an end portion of a tube (not shown) and applying under pressure at the inner side of the tube such that the balloon 1 is drawn inside out to the inner side of the tube.

[0062] Although not shown in the embodiment according to the figures it is advantageous when the tube 3 is tapered in the initial condition as seen from the inflatable body 2. As a consequence, in the initial condition, the end portion 6 can be pressed open less easily by elastic function of the proximal portion 7 on the end portion 6 which is located therein, when the end portion 6 remains within the proximal portion 7 and does not terminate beyond the transfer portion 4 in the direction of the inflatable body 2.

[0063] By the way, it is not necessary that the channel 8 is enveloped by a sheet material which is made of a single piece. The valve 5 can be formed, for example, of at least two opposite elastic sheet members which form the channel 8 which is closed in peripheral direction. [0064] Fig. 5 an 6 show still an alternative embodiment of the balloon 1, wherein the tube 3 is provided at the channel 8 of an elastic rigidity 13 in peripheral direction of the channel 8 such that upon pressing it together the tube 3 opens and the channel 8 is opened. As a consequence, it becomes more simple to deflate an inflated balloon 1. The deflation of the balloon can also be performed by inserting a pin into the filling neck, possible a hollow pin. [0065] Fig. 7 and 8 show alternative embodiments of the balloon 1 according to the invention in the final condition. In the case of Fig. 7 there is started with a conventional balloon 1 in the initial condition wherein the end portion 6 is provided with a thicker portion 14 in the initial condition.

[0066] In Fig. 8 such a thicker portion 15 is arranged again at the filling opening 10. At the same time this is a fixation of the proximal portion 7 with respect to the loose end portion 6. Furthermore, in the embodiments of Fig. 7 and 8 sharp creases 11 are arranged in a part of the loose end portion 6 so as to maximize the closing characteristics of the channel 8. [0067] Fig. 10 and 11 show an alternative embodiment of the inflatable balloon 1 according to the invention in its initial condition and its final condition, respectively. The distal portion 6 is disposed between the proximal portion 7 and an end portion 16 of the tube 3 in this case, see Fig. 10a. The distal portion 6 is provided with sharp creases 11, which are indicated by means of hatching in Fig. 10a. [0068] In this embodiment the distal portion 6 is displaced in the direction of the inflatable body 2 through the proximal portion 7 until the entire proximal portion 7 is also displaced into the inflatable body 2. The remaining portion of the tube 3 which remains outside the inflatable body 2 is the end portion 16 in this case. This end portion 16 forms the filling neck 9 of the balloon 1 in the final condition. [0069] The proximal portion 7 and the distal portion 6 are connected to each other at a location which is indicated by the reference sign 12 in Fig. 11a. Although the proximal and distal portions 6, 7 in Fig. 11a seem to have the same length it is not necessary in practice. [0070] In this case, sharp creases 11 can be applied to the tube 3 in a simple way in the initial condition from the outside of the tube 3, because in the final condition the distal portion 6 is not turned inside out. Although in Fig. 11a the distal portion 6 has the same length as the portion having the sharp crease 11, this is not necessary in practice. The portion having the sharp crease 11 can be shorter for example than the distal portion 6. Furthermore it is possible that a part of the proximal portion 7 remains outside the inflatable body 2 in the final condition, so that the filling neck 9 is formed by a part of the proximal portion 7 and the end portion 16.

[0071] Fig. 9a-d illustrate an alternative method of manufacturing a balloon 1 according to the invention. Fig. 9a shows a side view of a balloon 1 having an inflatable body 2 and a tube 3 communicating therewith. The tube 3 projects outwardly from the inflatable body 2. Fig. 9b shows a next step according to the alternative method; an end portion 17 of the tube 3 is displaced in the direction of the inflatable body 2 along the outer side of the tube 3 (the fold line along which the end portion is folded is indicated by a dashed line in Fig. 9a) . As a consequence a new end portion 17' of the tube 3 arises at a distance of the inflatable body 2.

[0072] Then a channel-shaped member 18 made of a sheet material is fixed to the tube 3 at the new end portion 17' such that the channel-shaped member 18 communicates with the tube 3. This can be done by heat, pressure, adhesive or alternative adhesive methods. In Fig. 9c the fixation is illustrated by a welding seam 19. A part of the channel- shaped member 18 of the embodiment as shown in Fig. 9c is provided with sharp creases 11 which are directed inwardly, such as described in the explanation to Fig. 3a, as well. This can be easily arranged to the channel-shaped member 18, because this is a cylindrical piece of balloon material, for example, in which sharp creases 11 are applied from the outer side in longitudinal direction and which is then turned inside out.

[0073] In the next step a distal portion 6a of the channel- shaped member 18 is displaced in the direction of the inflatable body 2 through the tube 3, causing the portion 6a being turned inside out. The end portion 17 which is displaced along the outer side of the tube 3 is finally returned in the position of the initial condition, such as shown in Fig. 9a. Fig. 9d shows the final condition of the balloon 1, in which can be seen that the distal portion 6a is connected to the remaining portion of the balloon 1 at the welding seam 19.

[0074] In Fig. 12a-c still another alternative method of manufacturing an inflatable balloon 1 is illustrated. Fig. 12a shows the initial condition of the balloon 1 having the inflatable body 2 and the tube 3 communicating therewith and projecting outwardly from the inflatable body 2. Fig. 12a further shows a loose self-closing valve, which is a channel- shaped member 18 made of sheet material such as latex or the like. By means of hatching it illustrates that the channel- shaped member is provided with sharp creases 11, such that the valve has suitable closing characteristics as is explained hereinbefore.

[0075] Fig. 12a also shows an assembly pin 20 about which the channel-shaped member 18 can be clamped. This situation is shown in Fig. 12b. The creases 11 will not disappear permanently after applying the channel-shaped member 18 onto the assembly pin because of the material properties of the sheet material. Then the tube 3 of the balloon 1 is applied about the channel-shaped member 18 as illustrated in Fig. 12c. After that the tube 3 and the channel-shaped member 18 are attached to each other and the thus formed balloon 1 can be removed from the assembly pin 20.

[0076] Pulling the tube 3 over the channel-shaped member 18 can be facilitated by sliding means disposed at the outer side of the channel-shaped member 18. Attaching the tube 3 and the channel-shaped member 18 to each other can be performed by gluing, welding or an alternative adhesive method. [0077] In practice, when removing the balloon 1 from the assembly pin 20 the channel-shaped member will possible clamp to the assembly pin 20. This is no problem, however, because the channel-shaped member 18 projecting from the tube 3 can be pushed back easily through the tube 3 in the direction of the inflatable body 2 in this case. [0078] Another alternative method of manufacturing a balloon according to the invention is illustrated in Fig. 13a-b. In this case a closing valve is integrated in the balloon 1 during a standard manufacturing process of balloons 1 made of latex are such materials. In a so-called dipping process for manufacturing latex balloons a mold 21 having the shape of a deflated balloon 1 is submerged in liquid latex, after which after drying the thus formed balloon 1 is removed from the mold. [0079] In the method according to the invention as illustrated in Fig. 13a-b a channel-shaped member 18 is connected to a balloon-shaped mold 21 by pulling the channel- shaped member 18 over the longitudinal portion of the mold 21 such as indicated by the arrows A. The longitudinal portion of the mold 21 corresponds to the filling neck 9 of the balloon 1 which has to be formed. The channel-shaped member 18 has the same material properties as the embodiment mentioned above and can be pulled easily over molds of different diameters because of its elasticity. In Fig. 13b the mold 21 and the channel-shaped member 18 having the channel-shaped member 18 applied thereon is shown. Then, the mold 21 including at least a portion of the channel-shaped member 18 is submerged in liquid latex 22 by means of the dipping process as mention above, as illustrated by arrow B in Fig. 13b. After the dipping process the latex applied onto the mold 21 is dried, after which the thus formed balloon 1 is removed from the mold 21.

[0080] Preferably, at least a portion of the channel-shaped member 18 made of sheet material does not adhere to the latex which is applied during the dipping process in order to maximize the closing function of the channel in this portion. Therefore, a portion of the outer side of the channel-shaped member 18 can be provided with an anti-adhesive layer before the dipping process, such that that portion is free from the remaining portion of the balloon 1 in the final condition of the balloon 1. [0081] Still another alternative method of manufacturing a balloon according to the invention is illustrated in Fig. 14a-b. In this case again a channel-shaped member 18 is attached to the balloon 1 during a dipping process, but now the mold 21 is provided with a cavity 23. In this case the cavity 23 is applied such that a tubular portion 24 is formed in the mold 21. A portion of the channel-shaped member 18 is inserted into the cavity 23 of the mold 21, such as indicated by arrows C in Fig. 14a. It can be seen in Fig. 14b that an end portion 25 of the channel-shaped member 18 is connected to the mold 21 by folding back the end portion 25 about an end of the tubular portion 24 of the mold 21 onto an outer side of the mold 21. As a consequence of the elastic properties of the channel-shaped member 18 this end portion 25 remains fixed to the mold 21.

[0082] The mold 21 and the channel-shaped member 18 which is inserted therein according to the method as described above are submerged in liquid latex 22 as illustrated by the arrow D in Fig. 14b. The mold 21 can be submerged into the liquid latex 22 such, that the liquid latex 22 attains the folded end portion 25 and the balloon 1 is provided with a channel- shaped member 18 fixed thereto after drying. Since the channel-shaped member 18 is disposed in the cavity 23 of the mold 21 the balloon will have a shape as shown in Fig. 14c after removing the balloon 1 from the mold 21. The inflatable body 2, the tube 3 and the channel-shaped member 18 fixed thereto can be seen in this Fig. The distal portion 6a of the channel-shaped member 18 can be inserted inside out through the tube 3 in the direction of the inflatable body, such as explained regarding the method as illustrated in Fig. 9. Fig. 14c shows the displacement by means of the arrow E. [0083] Fig. 15 shows an alternative inflatable balloon 1 in an inflated condition having an inflatable body 2 and a filling neck 9 projecting outwardly from the inflatable body 2. In this case the balloon 1 is provided with a self-closing valve 5 formed by a closing member 26, which is freely movable within the inflatable body 2. The closing member 26 is spherical and can be a light ball, for example, such as a table tennis ball. The size of the closing member is larger than a smallest area of the filling neck 9 in order to prevent the closing member 26 from easily leaving the balloon 1. The closing member 26 has also a relatively large size in order to avoid that the closing member 26 is removed from the balloon 1 which may be dangerous for children. [0084] When the balloon is inflated, the closing member 26 can be displaced in the direction of the inflatable body 2. The closing member 26 has such a shape that it corresponds to a portion of an inner side of the inflatable body 2 at the filling neck 9 in the inflated condition such that the closing member 26 seals the inflatable body 2 with respect to the environment of the balloon 1 as a consequence of the pressure in the inflatable body 2 on the closing member 26, which is pressed against the inner wall of the inflatable body 2 as a consequence thereof.

[0085] From the foregoing it will be clear that when applying the method according to the invention a balloon including a self-closing valve can be manufactured in a relatively simple and cheap manner. It will also be clear that the inflatable balloon according to the invention forms a simple solution for a balloon including a self-closing valve.

[0086] The invention is not limited to the embodiments as shown in the drawings and described hereinbefore which can be varied in different ways within the scope of the invention.

Claims

1. Method of manufacturing an inflatable balloon (1) which is provided with a self-closing valve (5) in its final condition, wherein the self-closing valve (5) is inserted into the balloon (1), which, in its initial condition, comprises an inflatable body (2) and a tube (3) communicating therewith, which tube is made of a sheet material and projects outwardly from the inflatable body (2), characterized in that the valve (5) is applied by displacing a distal portion (6) of the tube (3) which distal portion is spaced from the inflatable body (2) in the initial condition in the direction of the inflatable body (2) through a proximal portion (7) of the tube (3) , the proximal portion (7) being adjacent to the inflatable body (2) so as to form a channel (8) by the distal portion (6), through which channel (8) the inflatable body (2) communicates with the environment of the balloon (1), until still a portion of the tube (3) remains outside the inflatable body (2), such that the remaining portion of the tube (3) forms a filling neck (9) for inflating the balloon (1), and after which the proximal (7) and distal portions (6) are fixed with respect to each other in the axial direction of the filling neck (9) in order to avoid a displacement of the distal portion (6) with respect to the inflatable body (2) outwardly in inflated condition thereof.

2. Method according to claim 1, wherein the distal portion is a loose end portion (6) of the tube (3) in the initial condition of the balloon (1) .

3. Method according to claim 2, wherein, before displacing the loose end portion (6) in the direction of the inflatable body (2) , an outer wall of at least a part of the loose end portion (6) is placed at two opposite locations in inward direction of the tube (3), after which in any case a force is applied on the tube (3) in direction substantially perpendicular to the displacement of the opposite locations, so as to apply a sharp crease (11) at the locations of the tube (3) which are displaced inwardly.

4. Method according to claim 2, wherein the balloon (1) is turned inside out in the initial condition, after which at least a part of the end portion (6) of the tube (3) is treated such that sharp creases (11) are formed at two opposite locations of the tube (3), after which the balloon (1) is turned again inside out, before the loose end portion (6) of the tube (3) is displaced in the direction of the inflatable body (2) .

5. Method according to claim 4, wherein the sharp creases (11) are formed by applying pressure from outside onto the tube (3) and increasing the temperature at least at the locations where the creases (11) are intended.

6. Method according to claim 1, wherein in the initial condition the distal portion (6) is disposed between the proximal portion (7) and an end portion (16) of the tube (3), and the remaining portion of the tube (3) which remains outside the inflatable body (2) is at least a part of the end portion (16) .

7. Method according to claim 6, wherein at least a part of the distal portion (6) is provided with sharp creases (11) at two opposite side edges of the tube (3) .

8. Method of manufacturing an inflatable balloon (1) which is provided with a self-closing valve (5) in a final condition, wherein the self-closing valve (5) is applied in the balloon (1) which comprises an inflatable body (2) and a tube (3) communicating therewith and projecting outwardly from the inflatable body (2) in an initial condition, characterized in that: the valve (5) is a channel-shaped member (18) made of a sheet material, which is attached to the tube (3) such that the channel-shaped member (18) communicates with the tube (3), after which the distal portion (6a) of the channel-shaped member (18) which is spaced from the tube (3) is displaced in the direction of the inflatable body (2) through the tube (3).

9. Method according to claim 8, wherein before the attachment of the channel-shaped member (18) to the tube (3) an end portion (17) of the tube (3) in an initial condition thereof is displaced along the outer side of the tube (3) in the direction of the inflatable body (2), so that a new end portion (17") of the tube (3) is formed at a distance of the inflatable body (2), to which new end portion (17') the channel-shaped member (18) is fixed, after which the distal portion (6a) of the channel-shaped member (18) is displaced in the direction of the inflatable body (2), and the end portion (17') is returned along the outer side of the tube (3) in the position of the initial condition.

10. Method according to one of the preceding claims, wherein the tube (3) is tapered in the initial condition, as seen from the inflatable body (2) .

11. Inflatable balloon (1) comprising an inflatable body (2) and a filling neck (9) projecting outwardly from the inflatable body (2) and including a filling opening (10) which filling opening is disposed at a distance of the inflatable body (2), which filling neck (9) and inflatable body (2) are made of latex, wherein the balloon (1) is provided with a self-closing valve (5) , characterized in that the valve (5) is formed of at least two opposite elastic sheet members (3) which form a channel (8) which is closed in peripheral direction, through which channel (8) the filling opening communicates with the inflatable body (2), wherein the sheet members (3) are formed such that they close the channel (8) at least when the pressure at the side of the valve (5) where the inflatable body (2) is disposed is higher than at the side of the valve (5) where the filling opening (10) is disposed.

12. Inflatable balloon (1) according to claim 11, wherein the sheet members (3) are made of latex.

13. Inflatable balloon (1) according to claim 11 or 12, wherein between the filling opening (10) and the inflatable body (2) the sheet members (3) are connected to the filling neck (9) .

14. Inflatable balloon (1) according to claim 13, wherein the sheet members (3) extend in the direction of the inflatable body (2) beyond a transfer portion (4) of the filling neck (9) to the inflatable body (2).

15. Inflatable balloon (1) according to one of the claims 11-14, wherein the sheet members (3) are shaped such, that at least a portion of the channel (8) has two opposite side edges where the cross section of the channel (8) forms an acute angle, such that in a rest condition the sheet members (3) substantially lie on each other.

16. Inflatable balloon (1) according to claim 15, wherein the sheet members (3) are made of a single sheet, in which at least one sharp crease (11) is arranged so as to form one of the side edges.

17. Inflatable balloon (1) according to one of the claims 11-16, wherein the sheet members (3) at the channel (8) are at least partly provided with an elastic rigidity in peripheral direction of the channel (8) such, that upon pressing thereof the sheet members (3) are displaced away from each other, so as to be able to deflate an inflated balloon (1) easily.

18. Method of manufacturing an inflatable balloon (1) which is provided with a self-closing valve (5) , wherein in the balloon (1) which, in an initial condition, comprises an inflatable body (2) and a tube (3) communicating therewith, which tube projects outwardly from the inflatable body (2), the self-closing valve (5) is applied, characterized in that the valve (5) is a channel-shaped member (18) made of sheet material, which is displaced through the tube (3) in the direction of the inflatable body (2), after which it is fixed to the tube (3) .

19. Method according to claim 18, wherein the channel- shaped member (18) is clamped onto an assembly pin (20) before inserting the channel-shaped member (18) into the tube (3), after which the tube (3) of the balloon (1) is applied about the channel-shaped member (18) in the initial condition, after which the tube (3) and the channel-shaped member (18) are fixed to each other and the thus formed balloon (1) is removed from the assembly pin (20) .

20. Method according to claim 19, wherein a sliding means is applied to the outer side of the channel-shaped member (18) before the tube (3) is applied thereabout.

21. Method of manufacturing an inflatable balloon (1) which is provide with a self-closing valve (5), which is a channel-shaped member (18) made of sheet material, characterized in that the channel-shaped member (18) is releasably connected to a balloon-shaped mold (21), after which the mold (21) including at least a portion of the channel-shaped member (18) connected thereto are submerged in liquid latex (22) by means of a dipping process and dried, after which the thus formed balloon (1) including the valve (5) is removed from the mold (21) , wherein at least a part of the portion of the channel-shaped member (18) which is also submerged is arranged such that it adheres to the liquid latex (22) .

22. Method according to claim 21, wherein the channel- shaped member (18) is applied about a portion of the mold (21), before the mold (21) including the channel-shaped member (18) applied thereabout is submerged into liquid latex (22).

23. Method according to claim 22, wherein a portion of the outer side of the channel-shaped member (18) is provided with an anti-adhesive layer before the dipping process so as to make that portion free with respect to the remainder of the balloon (1) after drying.

24. Method according to claim 21, wherein a part of the channel-shaped member (18) is inserted into a cavity (23) of the mold (21) before the channel-shaped member (18) is connected to the mold (21) so as to protect the portion inserted into the cavity at least partly from the liquid latex (22) during the dipping process.

25. Method according to claim 24, wherein the cavity (23) is at least partly formed by a tubular portion (24) of the mold (21), wherein an end portion (25) of the channel- shaped member (18) is folded outwardly back about an end of the tubular portion (24) onto an outer side of the tubular portion (24) to the mold (21) so as to connect the channel- shaped member (18) with the mold (21), wherein at least the end portion (25) contacts the liquid latex (22) during the dipping process.

26. Inflatable balloon (1) comprising an inflatable body (2) and a filling neck projecting outwardly from the inflatable body (2) including a filing opening (10) which is disposed at a distance of the inflatable body (2), wherein the balloon (1) is provided with a self-closing valve (5), characterized in that the valve (5) is formed of a closing member (26) , which is freely movable within the inflatable body (2) and has a larger size than the smallest cross- sectional area of the filling neck (9) in an inflated condition of the balloon (1), wherein the closing member (26) has such a shape that in an inflated condition of the inflatable body (2) it contacts a portion of an inner wall of the inflatable body (2) at the filling neck (9) such, that the closing member (26) closes the inflatable body (2) with respect to the environment of the balloon as a consequence of the pressure in the inflatable body (2) on the closing member (26) which is pressed against the inner wall of the inflatable body (2) as a consequence thereof, when the closing member is displaced in the direction of the filling neck (9) .

27. Inflatable balloon (1) according to claim 26, wherein the closing member (26) is spherical.

28. Inflatable balloon (1) according to one of the claims 11-17, wherein the inflatable body (2), the filling neck (9) and the valve (5) are made of one sheet.