The invention relates to a lid for a reservoir to be connected to a liquid spraying device, in particular a lid with a ventilation system for venting the reservoir.

Today, different kinds of liquid spraying devices are known. These kinds of liquid spraying devices use different techniques to transport liquid from a reservoir to a spraying mechanism. In general, suction feed liquid spraying devices and gravity feed liquid spraying devices are known. In the case of the suction feed liquid spraying devices, the reservoir is generally located below the spraying mechanism and the liquid is sucked from the reservoir by negative pressure. In the case of the gravity feed liquid spraying devices, the reservoir is generally located above the spraying mechanism and the liquid can flow from the reservoir towards the spraying mechanism according to the principle of gravity.

Independent from these different techniques, it is desirable to have an undisturbed flow of the liquid from the reservoir to the spraying mechanism in order to achieve a uniform application of the liquid onto a surface which has to be treated. WO 2005/077543 Ai describes a reservoir for a gravity feed liquid spraying device with a venting opening at the bottom of the reservoir, wherein the venting opening is closed when the reservoir is filled with liquid and the venting opening is opened after the complete spraying device is turned upside down so that the reservoir is moved above the spraying mechanism for spraying. However, open- ing and closing the venting opening at the correct point in time is cumbersome and may cause problems such as that liquid may leave the reservoir, if the venting opening is not closed correctly. WO 2009/046806 Ai describes a lid for a reservoir for a gravity feed liquid spraying device. The lid is provided with a venting opening constructed as a labyrinth seal formed by three cylinders being plugged into each other. The labyrinth seal prevents that liquid flows out of the reservoir when the reservoir is in its up- right position and when the reservoir is in its upside down position for the liquid spraying process. However, the labyrinth seal cannot always prevent that liquid flows into the labyrinth seal. This is in particular the case, when the reservoir is turned. Moreover, the labyrinth seal protrudes from the lid, such that the lid cannot be stored in a space-saving manner.

Therefore, there exists the need to provide a reservoir with a venting opening for venting the reservoir which reliably prevents that liquid could flow out of the reservoir during use. In addition, there exists the need to design such a reservoir in such a way that its individual components are storable in a space-saving manner as well as easily and securely transportable. This need is fulfilled by the lid for a reservoir according to independent claim 1.

The lid for a reservoir to be connected to a liquid spraying device according to the invention comprises a ventilation hole, a flexible tube, and a valve, wherein the combination of the ventilation hole, the flexible tube, and the valve forms a ventilation system which allows an air movement from the outside of the reservoir via the ventilation system to the inside of the reservoir while it blocks the movement of a liquid from the inside of the reservoir via the ventilation system to the outside of the reservoir.

This new ventilation system provides a reliable venting of the reservoir, i.e. without the risk that liquid flows into the venting system. This is the case, since the ventilation hole has not to be opened or closed when the liquid spraying device is used. The flexible tube serves as an extension of the ventilation hole into the in- side of the reservoir and is sealed at its distant end by the valve in a liquid tight manner. The valve prevents that liquid can flow out of the reservoir into the ventilation system during use, i.e. during the refilling process, during turning the spraying device and during the spraying process. In addition, it is possible to easi- ly refill the reservoir by removing the lid from the reservoir together with the ventilation system.

Due to the new ventilation system, the lid according to the present invention could be easily stored and transported. This is the case, since the tube is flexible. While the prior art lid has a protruding labyrinth seal formed by three rigid cylinders, the flexible tube according to the present invention enables that the tube and therefore the ventilation system could be placed in a position in which it does not disturb during storing and transporting. In accordance with the present in- vention, a flexible tube is a tube which could be bent at at least one point of the length of the tube. However, in a preferred embodiment, the flexible tube could be bent at several points, i.e. at at least two points. In a further preferred embodiment, the flexible tube could be bent at any point of the length. Such a tube may be named a completely flexible tube.

Basically, the liquid used for the spraying process may be any flowable material, but preferably one of color, paint, glue, or garden chemicals.

In a preferred embodiment, the flexible tube is made at least in part of a flexible material having at the same time a sufficient stiffness in order to prevent that the flexible tube collapses due to liquid pressure. Preferably, the flexible tube is made at least in part of rubber, silicone, or plastic, wherein plastic is preferably polyethylene or polyprophylene. In a further preferred embodiment, the flexible tube is adapted for allowing the valve to be located above a liquid level in the reservoir during operation by means of a gravity feed liquid spraying device. This may be achieved, for example, by using a tube having a suitable length. In general, the reservoir may be formed by a lid and a container. For filling the reservoir, the container is placed on its bot- torn and the liquid to be sprayed is filled in the container through an opening at the opposite side of the container, i.e. opposite to the bottom. In subsequent steps, the opening is closed by the lid to form the reservoir and the reservoir is connected to the spraying device. When the reservoir and the spraying device are turned, some liquid flows into the lid and in the spraying device. As a conse- quence, in this upside down position, the reservoir is not completely filled with the liquid. Therefore, a tube with a suitable length will cause that at least the valve connected to the tubes located above the liquid level when the reservoir is upside down and the spraying device is in operation. Preferably, the tube has also a sufficient stiffness to locate the valve above the liquid level.

In general, the lid with the ventilation system may consist of one, two, three or more pieces. The lid, the flexible tube, and the valve can be formed in one piece. This does not necessarily mean that the ventilation system is produced in one piece. The components of the ventilation system such as the flexible tube and the valve may be produced separately but permanently put together, e.g. glued to form one piece. However, it is also possible that at least some of the components are removable connected to each other and therefore form several pieces.

In a further preferred embodiment, at least parts of the ventilation system have a buoyancy that is high enough to enable the valve to float on the liquid. For example, the shape and or the material of the valve may be chosen so that the valve floats on the liquid. This may be supported by the shape and/or the material of the flexible tube.

In a further preferred embodiment, parts of the lid form a cavity, wherein the flexible tube and the valve are adapted for being arranged at least in part in the cavity. In particular, the flexible tube and the valve could be stored at least in part in the cavity during transport of the lid. This substantially reduces the space needed by the lid as compared to some lids known in the prior art. Additionally, the lid can be easily sealed with a material that can be removed before using the lid, such that the lid is protected from dust and dirt during transport and storing. However, when the lid is connected to a container of a reservoir, the flexible tube and the valve could be taken out of the cavity so that the valve is located above the liquid level in the reservoir during operation by means of a gravity liquid spraying device. As described above, the flexible tube could be realized in different ways. For example, the flexible tube could be a completely flexible tube which is flexible enough to be arranged circular or serpentinous in the cavity. Since the valve is preferably small and compact, it either marginally protrudes beyond the dimen- sions of the lid itself or does not protrude beyond the dimensions of the lid itself at all when arranged in the cavity. Preferably, the cavity is a groove nearby the edge of the lid.

In a further preferred embodiment, the flexible tube comprises nearby the ventilation hole a hinge that allows an orientation of the flexible tube in various directions. Preferably, the hinge is a section of the flexible tube comparable with the bellows-shaped section of a straw. Nevertheless, other implementations of the hinge are conceivable so long as an air movement through the hinge as well as an airtight sealing of the hinge against the inside of the reservoir are ensured.

In a further preferred embodiment, the lid further comprises means for detachable connecting the flexible tube and/or the valve to the lid at a location apart from the ventilation hole. This means for detachable connecting enables that the flexible tube and the valve stay at least in part in the cavity during transport of the lid.

In a further preferred embodiment, the means for detachable connecting the flexible tube and/or the valve to the lid comprises at least one clamp. Preferably, the at least one clamp is a horseshoe-shaped tube clamp comprising a central, preferably circular, opening for the flexible tube and two slightly movable wing parts forming an inlet opening to the central opening. Thereby, the width of the inlet opening is smaller than the smallest diameter of the central opening, such that the wing parts have to be moved away from each other in order to insert the flexible tube into the central opening. Such a horseshoe-shaped tube clamp is advantageous since the connection of the flexible tube with the lid can be easily detached by simply pulling out the flexible tube of the horseshoe-shaped tube clamp. However, the person skilled in the art knows several alternatives, how the flexible tube could be connected to the lid.

In a further preferred embodiment, the valve comprises a valve body forming a first opening and a second opening, wherein the first opening is adapted to be connected to the flexible tube in such a way that the flexible tube generally extends in a layer parallel to the second opening. Thereby, air can enter the inside of the reservoir via the second opening of the valve body. The flexible tube extend- ing in a layer parallel to the second opening is advantageous since herewith the flexible tube and the valve can be arranged in a cavity formed by parts of the lid in an even more space-saving manner. In particular, it can be avoided that the valve protrudes beyond the dimensions of the lid itself.

In a further preferred embodiment, the valve body further comprises a valve seat having a sealable valve opening. The sealable valve opening enables that a movement of liquid from the second opening to the first opening is blocked, while a movement of air from the first opening to the second opening is possible. Preferably, the sealable valve opening is arranged in a layer which is parallel to the second opening, but which is substantially perpendicular to the layer of the first opening. This is advantageous since herewith the flexible tube does not have to be connected directly to the sealable valve opening in order to allow an air movement from the outside of the reservoir to the inside of the reservoir. Instead, the flexible tube can be connected to the valve at the most technically appropriate position with regards to storing the lid as space-saving as possible, namely at the first opening.

In a further preferred embodiment, the valve comprises venting means arranged at the side of the sealable valve opening facing the second opening, wherein the venting means prevent that liquid from the inside of the reservoir gets into the flexible tube and allow air movement from the outside of the reservoir into the reservoir.

Suitable venting means may be formed by an air-permeable but liquid-tight body. Such a body which is air-permeable and liquid-tight could prevent that liquid drops get into the flexible tube and at the same time allows an air pressure compensation between the outside of the reservoir and the inside of the reservoir. An example for a suitable air-permeable but liquid-tight body is a fine grid that is air- permeable all the time. However, it is also possible to use an air-permeable but liquid-tight body that becomes only air-permeable when the air pressure in the inside of the reservoir decreases. In a preferred embodiment, the venting means comprise an elastically deforma- ble membrane. On the one hand, this elastically deformable membrane can be arranged in a closed position, where it lies on the valve seat and seals the sealable valve opening by covering the sealable valve opening. In such an arrangement, it is advantageously prevented that liquid drops get into the flexible tube as well as that air moves from the outside of the reservoir via the ventilation system to the inside of the reservoir when there is no need for an air pressure compensation between the inside of the reservoir and the outside of the reservoir. When the air pressure in the inside of the reservoir decreases, at least a part of the elastically deformable membrane curves away from the valve seat. Hence, on the other hand, the elastically deformable membrane can be arranged in an opened position, where it is at least partially lifted from the valve seat and thus forms a certain air passage. Such an arrangement is advantageous since air can flow from the outside of the reservoir via the ventilation hole, the flexible tube, the first opening of the valve body, the sealable valve opening, the air passage, and finally the second opening of the valve body to the inside of the reservoir and thus an air pressure compensation between the outside of the reservoir and the inside of the reservoir can take place. Upon completion of such an air pressure compensation, the elastically deformable membrane moves back to its closed position. The elastically deformable membrane may be made at least in part of any elastic material, but preferably it is made at least in part of rubber, silicone, or plastic, wherein plastic is preferably polyethylene or polyprophylene. Advantageously, also in the opened position it is prevented that liquid drops get into the flexible tube. This is, since the air passage is only present if air flows from the outside of the reservoir to the inside of the reservoir in order to compensate air pressure and as long as air flows, liquid cannot flow in the opposite direction into the valve.

In a further preferred embodiment, the venting means further comprise a sealing liquid enhancing the sealing, wherein the sealing liquid is located in at least one area between the valve seat and the elastically deformable membrane. Preferably, the sealing liquid is a silicone oil which is located in concentric channels surrounding the sealable valve opening. Such a sealing liquid is advantageous since it enables an even better liquid tightness as well as air tightness when the elastically deformable membrane is arranged in the closed position. By the lid for a reservoir described above, for the first time a lid for a reservoir with a venting opening which reliably prevents that liquid could flow out of the reservoir during use is provided. In addition, the lid is designed in such a way that it is storable in a space-saving manner as well as easily and securely transportable.

In the following, the invention is further described by reference to the schematic illustrations shown in the figures, wherein:

FIG. l shows a cross section of an embodiment of a lid for a reservoir according to the invention; shows a side view of a ventilation system arranged in a cavity formed by parts of an embodiment of a lid for a reservoir according to the invention; and

FIG. 3 shows a cross section of an embodiment of a valve for a lid according to the invention.

FIG. l shows a cross section of an embodiment of a lid 2 according to the invention when it is connected to a container 18 to form a reservoir 2 and turned into the upside down position to be used with a gravity feed spraying device. The lid 2 comprises a ventilation hole 3, a flexible tube 4, and a valve 5. In the following, the combination of the ventilation hole 3, the flexible tube 4, and the valve 5 is referred to as the ventilation system. As shown in Fig. 1, the ventilation system, in particular the flexible tube 4 is adapted to allow the valve 5 to be located above a level 7 of a liquid 6 in the reservoir 1 during operation by means of a gravity feed liquid spraying device. Among others, this could be achieved due to a sufficient length and a sufficient stiffness of the flexible tube 4.

FIG. 2 shows a side view of a lid 2 according to the invention as it may be transported. The flexible tube 4 and the valve 5 are arranged in a cavity formed by parts of the lid 2. In the embodiment shown in FIG. 2, the flexible tube 4 and the valve 5 are completely arranged in the cavity. Nevertheless, according to the invention it is sufficient if parts of the flexible tube 4 and the valve 5 are arranged in the cavity. For arranging the flexible tube 4 and the valve 5 in the cavity, in the present embodiment the flexible tube 4 comprises nearby the ventilation hole 3 a bellows-shaped section 8 which allows the flexible tube 4 to be bent so that it could easily be arranged in the cavity of the lid 2. However, the bend of the flexible tube 4 can also be achieved by any kind of hinge or by simply utilizing the elasticity of the flexible tube itself. Furthermore, for arranging the ventilation system in the cavity, in the present embodiment the flexible tube 4 is circular bent. In order to prevent that the flexible tube 4 returns from its circular bent position in its original position due to forces resulting from its elasticity, the lid 2 further comprises a horseshoe-shaped tube clamp 9 in whose central opening the flexible tube 4 is inserted. Nevertheless, any kind of clamp and any kind of easily removable adhesive tapes or adhesive points may be used for detachable connecting the flexible tube 4 and/or the valve 5 to the lid 2.

FIG. 3 shows a cross section of a valve 5 of an exemplary embodiment ventilation system according to the invention. In the here shown embodiment, the valve 5 comprises a valve body 10 forming a first opening 11 and a second opening 12. The flexible tube 4 is connected to the first opening 11 and generally extends in a layer parallel to the second opening 12. The valve body 10 also comprises a valve seat 13 having a sealable valve opening 14. Venting means are arranged at the side of the sealable valve opening 14 facing the second opening 12 in order to prevent that liquid 6 from the inside of the reservoir 1 gets into the flexible tube 4 and in order to permit an air movement from the outside of the reservoir 1 into the reservoir 1. For this purpose, the venting means in the here shown embodiment comprise an elastically deformable membrane 15 as well as a sealing liquid 16 located between the valve seat 13 and the elastically deformable membrane 15.

In FIG. 3, the sealable valve opening 14 is shown in a closed state as well as in an opened state. In the case of the sealable valve opening 14 being in its closed state, the elastically deformable membrane 15 is arranged in a closed position. In this closed position, the elastically deformable membrane 15 completely covers the sealable valve opening 14 by lying on the valve seat 13. The sealing between the membrane 15 and the valve seat 13 is further improved by the sealing liquid 16. Due to this combination, an outstanding liquid tightness as well as air tightness is ensured in the closed position. In the here shown embodiment, the sealable valve opening 14 changes from its closed state to its opened state when the air pressure in the inside of the reservoir 1 decreases during the spraying process. During the change from the closed state to the opened state, a part of the elastically deform- able membrane 15 curves away from the valve seat 13 in the direction of the second opening 12 of the valve body 10. At the same time, other parts of the elastically deformable membrane 15 are forced not to curve away from the valve seat 13 and instead to still lie on the valve seat 13 by means of a stop element 17. Such a stop element 17 prevents the elastically deformable membrane 15 from too extensively lifting from the valve seat 13 and thus prevents an air passage formed thereby getting too large. Hence, in the case of the sealable valve opening 14 being in its opened state, the elastically deformable membrane 15 is arranged in an opened position forming an air passage for allowing air pressure compensation. Thereby, air flows from the outside of the reservoir 1 via the flexible tube 4 and the valve 5 to the inside of the reservoir 1 and at the same time the elastically deformable membrane 15 steadily moves back to its closed position up to the completion of the air pressure compensation.