Field of the invention

The invention relates generally to cap devices, and more particularly to a cap device suitable for use in laboratory processes. The cap device allows dispersion of a liquid into a container or flask during the process, and acts as a condenser allowing reflux of the liquid and vapour.

Introduction

Research facilities, analytical lab-scale environment and quality control operators employ glassware such as beakers and flasks as containers and mixing jars for a variety of solutions, compounds and chemicals. Certain reactions, in particular processes involving acids and heating, can cause some of the solution to splash out of the glassware or to evaporate during the process. The use of watch glasses that fit over the opening of a flask or a beaker usually resolves these problems. The shape of the watch glass lends itself to sit loosely on the flask or beaker giving vent during heating processes and helps to maintain to some extend a suitable temperature in the container. In order to yield most profitable operation for some applications, it is suitable that the generated vapours continuously condense to return to the process from which they originated. Since watch glasses are not stuck on the flask, they are

susceptible to being knocked of the flask and being broken during manipulation or intensive bubbling induced along the process. Because their processing by a robot arm is not straight forward they are also not ideal for use in automation processes. Caps have been developed to overcome the shortcomings of the watch glasses. However, a major disadvantage linked to the use of the caps and watch glasses remains the difficulty to gain access to the container' s content, for example for adding material or liquid necessary during the chemical process or even for rinsing purpose. Repeated removal of caps is time consuming and has a

negative effect on the efficiency of the process.

Accordingly, there appears to be a need for a cap that provides a solution to the problems posed.

Brief description of the invention

The general object of the present invention is thus to provide a cap device suitable for use in a laboratory process, which cap device allows dispersion of a liquid in a flask or container. The cap device is capable of

maintaining a suitable temperature inside a container or flask. It is a further general object of the present invention to provide a cap device that allows condensation of vapours and efficient return of the condensate to the process. It is also an object of the present invention to provide a reusable cap device that is sufficiently sturdy to withstand heat, contact with acid and repeated washings, thereby encouraging multiple uses. The present invention overcomes shortcomings of the conventional art and may achieve other advantages not contemplated by the

conventional devices.

It is an aspect of the invention to provide a cap for dispensing liquid into a recipient. Said cap preferably comprises : (a) at its top edge portion: a container comprising an inner space bounded by a bottom provided with at least one hole and a side wall which lower outer end includes an outward projection, and

(b) at its bottom edge portion: a body having a circular base extending downwardly towards the inner side wall of the recipient.

The container to receive a supply of liquid has preferably a circular base. Preferably, the container is a cylinder bounded by a bottom. In all of the embodiments, the inner space of the container is bounded by a bottom with at least one hole. The bottom has thus most preferably a circular form with at least one hole in it, preferably at least three holes, at least six holes, at least eight holes or at least twelve holes. More preferably, the bottom contains three holes, six holes, eight holes, twelve holes, or sixteen holes, which holes preferably align on one, two or more circles. In case of alignment on multiple circles, the holes may be in number equally distributed over the circles. In

particular, two successive holes on the same circle may align at the same angle on the circle. The circular bottom and the circles aligning the holes have preferably the same centre .

In a preferred embodiment, the bottom of the container has an inclined plane. In particular, the bottom surface may include an upward or downward projection. It is essential for the invention that at least one hole is contained in the part of the bottom surface that is most depressed. As a consequence, flow of the liquid is directed towards the inlet opening of the hole allowing dispersion of the

complete amount of liquid fed to the container. In one embodiment outlined with reference to figures 1 and 2, the invention in this aspect is further characterized wherein the cylinder has a gradually upward protruding bottom from its inner sidewall in the direction of the centre of the bottom surface. Preferably, the upward projection of the bottom is cone-like. The cone-like projection may position at a distance from the inner

sidewall of the container. The bottom part between the inner side wall and the cone-like projection is preferably flat. Preferably, the holes in the bottom are located adjacent to the inner sidewall of the container. The holes may align on one circle and are proportionally distributed over the circle. In one embodiment, the holes are in the most depressed part of the bottom, preferably in the flat bottom part. Further, the holes may have a bracket-like form or slot-like form, with the hollow side aimed to the centre of the circle. In a particular embodiment, the inner vertical side of the holes is provided with groves. The holes are preferably small channels that reach through the bottom.

In an alternative embodiment outlined with reference to figure 3, the invention in this aspect is characterized wherein the cylinder has a gradually downwardly protruding bottom from the inner side wall toward the centre of the bottom surface. In particular, the bottom is provided with holes. Preferably, half of the holes align on a first small circle at the centre of the bottom surface, and the remainder align on a second larger circle in the bottom surface. Preferably, the diameter of the larger circle in the bottom is at least two times less or at least two times less than the inner diameter of the cylinder. Preferably, the holes are circular fluid inlet openings of small

channels directing the flow of fluid towards the bottom edge portion of the cap. The inner space of the cylinder bounded by the bottom is preferably bowl-shaped or cone-like shaped. The channels are further characterized wherein their fluid inlet opening has a minimal diameter preventing clogging of the inlet fluid. The fluid inlet opening is also

characterized in having a maximum diameter preventing excessive loss of the temperature inside the recipient and preventing excessive evaporation of the recipient's fluid. The diameter of the fluid inlet opening depends on the material and surface tension. The channels are further characterized wherein the fluid outlet opening is equal or larger than the fluid inlet opening. The opposite scenario may also apply. The channel may have a straight structure, or alternatively be curved or bent. In the embodiment outlined with reference to figure 3 both forms apply. Half of the channels are curved or bent in a way to direct the fluid leaving the outlet opening towards the bottom of the cap. Particularly, these channels have a first straight channel part that connects at an angle with a second

straight channel part, introducing a bend in the channel. In a particular embodiment, the second channel part is slot ^¬ like shaped, improving maximal drain from the cap.

The bottom of the recipient may also include a venting opening or venting tube. The venting improves fluent passage of the liquid in the container through the channels into the recipient.

It is suitable that the volume of the container of the cap is adapted to the quantity of liquid aimed for dispersion. The side wall bounding the inner space of the container is thus adjusted in height and shape, preventing liquid

overflow. In a preferred embodiment, the inner space of the container is bounded by a bottom provided with at least one hole and a sloping inner side wall directing the fluid towards the hole. Alternatively, the container has vertical inner side wall in order to maximize the inner space volume of the container. The cap for dispensing liquid is further characterized wherein the container to receive a supply of liquid has an outward projection at the lower side portion of its outer side wall. The outward projection of the side wall of the container is further characterized wherein it stably fits over the opening of a recipient to minimize evaporation of the liquid, to maintain a suitable temperature inside the recipient, and to facilitate reflux of condensate generated along the process. The recipient is preferably a flask, preferably the neck of a flask, more preferably the neck of an Erlenmeyer. It is essential to the invention that the dimension of the outward projection of the vertical side wall of the container is adjusted to fit over the opening of the recipient.

In one embodiment outlined with reference to figures 1, 2 and 3, the invention is further characterized in that the outward projection of the container is in the form of a ring-like structure. The ring-like structure has a stepwise milling pattern which allows tight closing of the opening of the recipient. Preferably, the ring-like structure has an outer ring circle which downwardly decreases in radius, guiding the smaller part of the ring to enter into the neck opening of the flask. Thus, the ring-like structure is at its top edge portion composed of one, two or more rings stuck together, which lower ring then further downwardly gradually decreases in radius at the bottom edge portion of the ring-like structure. Preferably, the largest outer diameter of the gradually decreasing part is smaller than the outer diameter of the ring in such a way that a

horizontal face or plane is created between the ring and the decreasing part of the ring-like structure. This plane allows closing of the recipient, provides additional

stability and is preventing the cap from sliding. In all embodiments of the invention, the largest diameter of the outer ring circle of the ring-like structure exceeds or fits to the diameter of the outer neck circle of the recipient and is preventing the cap from falling into a recipient flask. Thus, the container and ring-like structure of the cap are constructed in a way that allows easy robotic manipulation .

The cap for dispensing liquid is further characterized wherein the bottom edge portion has a body comprising a cylindrical or a circular base extending outwardly towards the inner side wall of the recipient. Preferably, the cylindrical or circular base extends downwardly in radial outward direction to form an outward projection, which outward projection then further downwardly tapers off to a horizontal circular plane or a pointed tip. The construction of the bottom edge portion of the body is such that vapors and liquid given off are condensed to a liquid which has maximal drop back into the reaction vessel from the circular plane or pointed tip that forms the bottom end of the body. Thus, the cap is suitable for use in reactions requiring reflux of reagents. Preferably, the outward projection of the body comprises at least one shape of extension. In an embodiment outlined with reference to figures 1 and 2, it applies that the upper part bottom edge portion of the cap comprises a cylinder, which cylinder extends downwardly in radial direction to form an outward projection that tapers off to a circular face at its bottom edge. In an alternative embodiment as shown in figure 3, the cylindrical or circular base of the body downwardly increases in

diameter to attain a maximum diameter, which maximum

diameter then further downwardly decreases to reach the centre of the circular base. Thus, the outward projection tapers of to a pointed tip, and the body looks like a spinning top. The body's extension, increase or decrease as contemplated by the present invention is preferably in radial direction and curve formed, slope formed, archwise formed or straight formed.

The arrangement of the outward projection on the bodies shown in figures 1, 2 and 3 implies that the body's outer surface extending from the body' s cylindrical or circular base to the circle representing the body's horizontal conic intersection with maximum diameter, directs the flow of liquid in the first instance towards the inner side wall of the recipient. This is particularly advantageous in processes requiring removal of substances and chemicals deposited on the side wall of the recipient during or after a chemical or heating process. The arrangement allows, for instance, rinsing of the inner side wall of the recipient with water or other liquids. Further, the arrangement implies that the area extending from the circle representing the body's horizontal conic intersection with maximum diameter towards the pointed tip or circular plane, directs the fluid towards the tip nipple or circular plane. This arrangement allows optimal reflux and rinsing of the lower surface of the cap. The later is for instance particularly advantageous when violent chemical reactions with splashing and clotting against the cap are involved in the process. As shown in figure 2, the body may contain further channels having their inlet openings located between the body' s cylindrical or circular base and the circle representing the body's horizontal conic intersection with maximum diameter, and having their outlet openings located between the circle representing the body's horizontal conic intersection with maximum diameter and the pointed tip or circular plane at the end of the body. Such an arrangement allows

simultaneous rinsing of the recipient and the cap. It is essential to the invention that the dimension of the body is adjusted to the recipient, more in particular to the diameter of the neck of the recipient. In all embodiments, it is essential to have a space allowing passage of fluid between the body part at its maximal diameter and the inner side wall of the recipient. Accordingly, the cap for dispensing liquid is further characterized wherein the outward projection of the cylindrical base positions at a distance from the inner side wall of the recipient. More in particular, the circle representing the body's horizontal conic intersection with maximum diameter positions at a distance from the inner side wall of the recipient. It is essential to the invention that the distance between the body and recipient still allows the fluid coming from the outlet holes to hit or contact the inner side wall of the recipient. In addition, a body which positions to the inner side wall as described lends itself to prevent excessive loss of the content in the container through evaporation or bubbling induced during the process, allows maximal reflux and contributes in maintaining the suitable temperature in the container. As discussed, the container to receive a supply of liquid has a bottom with holes. The fluid inlet openings of the holes in the container direct the fluid through small channels towards the bottom edge portion of the cap.

In one embodiment outlined with reference to figures 1 and 2, the invention in this aspect is further characterized wherein the bottom is provided with through holes having a fluid inlet opening and a fluid outlet opening. The fluid inlet opening is located adjacent to the inner sidewall of the container, and the fluid outlet opening is located adjacent to the outer sidewall of the circular base of the body located at the bottom edge portion of the cap. As such, the liquid coming out of the outlet opening of the hole flows over the outer surface of the body, and is directed primarily towards the inner side wall of the recipient. The outward projection is constructed to allow optimal

streamlining of the fluid towards the inner sidewall of the recipient, which is important for rinsing purpose. When the flow of the liquid drops, the liquid will not longer hit the inner sidewall of the recipient, but rather move to the pointed tip or circular base of the body. As discussed, the bottom edge portion of the body comprises one or two sets of holes having inlet openings that align on one or more circles. The holes direct the flow of liquid towards the bottom edge portion of the cap. In another embodiment outlined with reference to figure 3, the invention is further characterized in wherein the cylindrical part of the body has a first set of fluid outlet openings. This first set of fluid outlet openings are from the channels having their fluid inlet openings aligned on the larger circle in the bottom surface of the container receiving the liquid. As discussed, the outward projection directs the flow of the liquid coming from the first set of outlet holes towards the inner side wall of the recipient or flask. In an additional embodiment, the invention is further characterized in wherein a second set of fluid outlet opening is present in the part of the body that extends from the circle representing the body's horizontal conic intersection with maximum diameter towards the pointed tip. This second set of fluid outlet openings are from the channels having their fluid inlet opening aligned on the smaller circle in the bottom surface of the container.

Thus, the second set of outlet holes is positioned between the outward projection of the body and the pointed tip. As discussed, the surface of the outward projection tapering off to the pointed tip directs the liquid coming from the second set of outlet holes to drop off from the bottom of the cap at a single point. This way, maximal drain from the cap is achieved.

It is another aspect of the invention to provide a cap adapted for the release of gas or steam. Said cap comprises preferentially a venting opening allowing air passage. The venting improves fluent passage of the liquid in the

container through the channels into the recipient. In an embodiment outlined with reference to figures 2 and 3, the invention in this aspect is characterized wherein the cap contains a venting opening. Preferably, the container to receive a supply of liquid is provided with a venting opening in the form of a tube, preferably cylindrical, which provides a way for gases to escape from the recipient in a controlled manner. Preferably, the venting tube has an outlet opening positioned at the height of the container' s side wall. Preferably, the venting tube is centrally positioned in the protruding part of the bottom surface of the container and has an inlet opening positioned at the outer side of the cylinder of the body. Alternatively, the venting tube is adjacent to the inner side wall of the container and parallel to the outer side wall of the body' s cylinder, and has an inlet opening that position adjacent to the outer side of the cylinder of the body. For particular applications involving intense reactions, the tube may be a cylinder having a sloping end. The lower part of the sloping end may be directed towards the center of the container, directing overhead liquid eventually escaping from the tube towards the inner side of the container and making it run back down into the recipient. Thus in a preferred embodiment, a cap adapted for dispensing liquid into a recipient flask and optionally adapted for the release of gas or steam and optimized reflux is provided, wherein said cap comprises

(a) at the top edge portion, a container to receive a supply of liquid having

an inner space bounded by a bottom provided with holes, a vertical side wall which lower end contains an outward projection that stably fits over the opening of the recipient flask, and

optionally, a venting opening;

(b) at the bottom edge portion, a cylindrical base extending in radial direction to form an outward projection that positions at a distance from the inner side wall of the recipient flask, which outward projection

directs the flow of the liquid towards the inner side wall of the recipient flask, and

tapers off to a pointed tip or circular face directing the liquid to drop off from the bottom of the cap

According to a further preferred embodiment, the invention provides for a cap adapted for dispensing liquid into a recipient flask and adapted for the release of gas or steam, wherein said cap comprises

(a) at the top edge portion, a container to receive a supply of liquid having

an bowl-shaped inner space bounded by a bottom provided with holes extending into the bottom edge portion of the cap,

- a vertical side wall which lower end contains an

outward projection that stably fits over the opening of the recipient flask, and a venting tube parallel with the inner vertical side wall

(b) at the bottom edge portion, a body composed of a

cylindrical base extending in radial direction to form an outward projection positioned at a distance from the inner side wall of the recipient flask, which outward projection tapers off to a pointed tip, wherein

the cylindrical part of the body has a first set of outlet holes for the liquid, and

- a second set of outlet holes is positioned between the top of the outward projection and the pointed tip, and

the outward projection directs the flow of the liquid coming from the first set of outlet holes towards the inner side wall of the recipient flask, and

the surface of the outward projection tapering off to the pointed tip directs the liquid coming from the second set of outlet holes to drop off from the bottom of the cap at a single point.

It is also an object of the present invention to provide a reusable cap device that sufficiently sturdy to withstand heat, contact with acid and repeated washings, thereby encouraging multiple uses. Materials particularly suitable for this are ethylene polymers, polytetrafluoroethylene (Teflon®) , per-fluor-alkoxy-polymers , polyvinylidene

fluoride, quartz, stainless steel, glass. Such a cap is particularly suitable for use in leaching processes.

When used in automation processes, it may be suitable to adapt the weight of the cap according to the reach of the analytical balances used. The weigth of the analyte, recicipient, cap and liquid taken together should not exceed the maximum measurable weight limit of the balans.

Restrictions can thus be put on the kind of material

composing the cap and/or on the overall structure of the cap. Depending on the needs, elements such as the ring- structure, the thickness of the cylindrical sidewall of the container, the flat bottom plane of the container, the diameter of the body' s cylinder, the length of the body and the bottom edge plane may for instance be pronounced or less pronounced. Variations on slopes applied to walls, cone ^¬ like structures, cup-like structures or diameters of

cylinders for example, may be applied as well. Brief description of the drawings

The invention, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjuction with the accompanying description, in which similar reference characters refer to similar parts, and in which:

Fig. 1A is a sectional profile view of a cap.

Fig. IB is a top view of the invention illustrated in Fig. 1A

Fig. 2A is a top side perspective view of the cap. The black arrows indicate flow of the liquid leaving the outlet holes of the channels. Fig. 2B is a bottom side perspective view of the cap. The black arrows indicate flow of the liquid leaving the outlet holes of the channels. Fig. 2C is a sectional profile view of the invention illustrated in Fig. 2A. The black arrows indicate flow of the liquid through the channels.

Fig. 2D is a top view of the invention illustrated in Fig. 2A

Fig. 2E is a bottom view of the invention illustrated in Fig. 2A

Fig. 3A is a bottom side perspective view of the cap. The black arrows indicate flow of the liquid leaving the outlet holes of the channels.

Fig. 3B is a top side perspective view of the cap

Fig. 3C is a sectional profile view of the invention illustrated in Fig. 3A

Fig. 3D is a sectional profile view of the invention illustrated in Fig. 3A

Fig. 3E is a top view of the invention illustrated in Fig. 3A

Fig. 3F is a bottom view of the invention illustrated in Fig. 3A

Detailed description of the invention The invention will be described with respect to the

following non-limiting examples. The cap referred to in figures 1 to 3 is a cap resistant to temperatures of 260 °C particularly suitable for use in leaching procedures requiring high temperature and acid treatment. The cap of the present examples is developed to fit to an Erlenmeyer wide mounth 250 ml (WM250) . The cap mainly includes a top edge portion 1, and a bottom edge portion 2. The cap is adapted for dispensing liquid into a recipient flask and comprises at the top edge portion, a container 3 to receive a supply of liquid. The container is in the form of a cylinder, and its inner space is bounded by a circular bottom 4 provided with holes, and a vertical side wall closed in itself. 6.

Figure 1A illustrates a sectional profile view and Figure IB is a bottom view of the cap. In this example, it applies that the vertical side wall 6 of the container when looked at from the top side of the cap comprises an external side 8 which is round and an inner side 9 which is round. The lower end of the container contains an outward projection 10 in the form of an annular structure 12 and the projection has a stepwise milling pattern that allows tight closing of the opening of the recipient. The annular structure has an outer ring which downwardly decreases in radius under an angle a of 45°, guiding the smaller part of the structure to enter into the neck opening of the flask. It applies that largest outer diameter of the gradually decreasing part 11 is less than the outer diameter of the ring 12 in such a way that a horizontal plane or face 13 is created between the ring and the decreasing part of the annular structure. In this particular example, the largest diameter of the outer ring circle 12 of the annular structure is equal to the diameter of the outer neck circle of the recipient 15 and is

preventing the cap from falling into a recipient flask. When the recipient is an Erlenmeyer wide mounth 250 ml (WM250), the largest diameter 12 is 59 mm or more. The inner

circumference of the bottle neck is in close contact with the part of the annular structure that has the largest diameter as to embrace the decreasing part and to prevent the cap from sliding. The bottom surface 4 of the container has an inclined plane in the form of a gradually upward projection 14 from the inner side wall 9 of the container in the direction of the centre 7 of the bottom of the

container. The gradually upward projection has a cone-like form 14 and positions at a distance from the inner side wall 9 of the container, creating a flat bottom ring 4 of 2 mm between the cone-like structure and the inner side wall of the container. The line segment joining the apex to the base of the cone makes an angle χ relative to the horizontal of 35°. The most depressed part of the bottom 4 is provided with 3 bracket-like holes 5. Figure IB is a bottom view of the cap and illustrates that the bracket-like holes 5 that reach through the bottom, are proportionally distributed on the flat bottom ring 4, and have their hollow side aimed to the centre 7 of the ring. Each hole on the circle occupies a segment of the circle and has an angle β of 30°. The fluid inlet opening of the hole is located adjacent to the inner sidewall 9 of the container, and the fluid outlet opening is located adjacent to the outer sidewall 23 of the circular base of the body located at the bottom edge portion of the cap. Figure 1A further illustrates that the bottom edge portion 2 of the cap has a body 17 composed of a cylinder with diameter of 40 mm 18 extending downwardly to form an outward projection 19, that tapers off to a circular plane or face 20 having a diameter that is half of the largest diameter of the cone-like structure 14. The outer side wall 23 of the cylinder has the same diameter as the inner circle 22 bounding the flat bottom ring 4. The cylindrical base of the cylinder downwardly increases in diameter to attain a maximum diameter 21 that positions at a distance from the inner side wall of the recipient flask which maximum

diameter then further downwardly decreases to end in a circular plain 20 located at the bottom edge of the body. Figure 1A shows that the line segment joining the circle representing the circular base of the cylinder with the body's horizontal conic intersection with maximum diameter and the line segment joining the body's horizontal conic intersection with maximum diameter with the circle

representing the circular plain, are straight lines (24a and 24b) . The arrangement of the outward projection on the body implies that the body' s outer surface 24a extending from the body' s cylindrical or circular base 18 to the circle representing the body's horizontal conic intersection with maximum diameter 21, directs the flow of liquid in the first instance towards the inner side wall of the recipient, whereas the body' s outer surface 24b extending from the circle representing the body's horizontal conic intersection with maximum diameter 21 towards the circular plane 20, directs the fluid towards the circular plane. This is particularly advantageous in processes requiring removal of substances and chemicals deposited on the side wall of the recipient and on the lower part of the cap' s body during or after for instance a chemical or heating process. When the recipient is an Erlenmeyer wide mounth 250 ml (WM250), the body of the cap attains ideally a maximum diameter 21 of 45 mm and downwardly decreases to a diameter which is 2/3 less. The overall arrangement of the body at the bottom edge part of the cap allows optimal reflux and rinsing of the lower surface of the cap. This arrangement is also advantageous for keeping a suitable temperature inside the recipient.

Figures 2A to 2E illustrate another cap. Figure 2C is a sectional profile view of two caps and shows that parts of their container correspond to the container discussed with reference to Figures 1A and IB. One difference exists in that the vertical side wall of the container 3 when looked at from the top side of the cap comprises a sloping inner side 25, which inner side gradually extends in radial direction from the top of the side wall towards the annular bottom 4 of the container. A further difference exists in the presence of a venting opening in the form of a tube 26 centrally positioned in the cone-like upward protruding part 14 of the bottom surface of the container, attaining the height of the container's side wall. As a result, the line segment joining the apex to the base of the cone makes an angle χ relative to the horizontal of 45° instead of the 35° illustrated in figure 1A. Figure 2D is a top view of the cap and illustrates that the effect of efficient fluid passage from the container to the recipient is achieved with 12 proportionally distributed holes having annular openings 16 with a diameter of 2mm. A further difference best illustrated in Figures 2B and 2E exists in the presence of a further set of 6 holes 5 located in the body 17 at the bottom edge portion 2 of the cap. The holes are straight channels 27 having their inlet openings 28 located between the body' s cylinder 18 and the circle representing the body's horizontal conic intersection with maximum diameter 21, and having their outlet openings 29 located between the circle representing the body's horizontal conic intersection with maximum diameter and the circular plane 20 at the end of the body. Compared to the diameter of the holes in the container' s bottom, the openings of the further set of holes are larger and in his example 4 mm in diameter to prevent clogging. This further set of holes allows more adequate rinsing of the portion of the body that is most exposed to splashing from turbulence in the recipient. In Figures 2A, 2B, 2Ca and 2E, half of the first set holes and all of the second set holes are positioned on one vertical line, whereas in Figure 2Cb each hole of second set positions between two holes of the first set. This set up allows more adequate rinsing.

Figures 3A to 3F illustrate another cap. Figure 3C is a sectional profile view of the cap and shows that parts of the container correspond to the container discussed with reference to Figures 1A, IB, and 2A to 2E. One difference exists in that the container is a cylinder comprising a gradually downwardly protruding bottom from the inner side wall in the direction of the centre of the bottom surface. In this particular example, the bottom is bowl-shaped 30 and is a segment of a circle which centre positions outside the cap and vertically relative to the centre of the container. In another example (not shown in a figure) the downwardly protruding bottom is cone-shaped. Figure 3E, which is a top view of the present example, illustrates that the bowl- shaped bottom is provided with twelve holes 5 aligning on two circles. Six holes align on a first small circle 33 positioned at the centre of the bottom surface and are the fluid inlet openings of channels 27 that have a bend 31. Six holes align on a second larger circle having a diameter that is approximately half of the inner diameter of the cylinder. The channels positioned on the small circle have an angle δ of 37° relative tot the vertical. The sectional profile view of the cap in Figure 3C shows that the channels 27 which inlet holes align on the small circle have a first straight channel part 7a that connects at an angle with a second straight channel part 7b, introducing a bend in the channel. The first channel part 7a has a diameter of 2 mm, whereas the second channel part 7b has a smaller diameter of 1,5 mm. These bended channels direct the flow of liquid to the fluid outlet opening 29 positioned between the circle representing the body's horizontal conic intersection with maximum diameter 21 and the pointed tip 31 at the end of the body. In an alternate version of the cap (not shown in a figure) , the second channel part of the bend channel is slightly slot-like shaped, improving maximal drain from the cap.

Thus, the upper part bottom edge portion of the cap

comprises a cylinder 18, which circular base downwardly increases in diameter to attain a maximum diameter 27, which maximum diameter then further archwise and downwardly decreases to reach the centre of the circular base 31.

Thus, the surface of the outward projection tapers archwise off to a pointed tip, giving the body the appearance of a spinning top. Figure 3D shows that the six holes aligning on the larger circle are the fluid inlet openings 28 of channels that have a straight structure 7c. These straight channels have a diameter of 2mm and direct the flow of fluid to the fluid outlet opening 29 positioned in the cylindrical part of the body 18. In all examples, the cap for dispensing liquid has an outward projection of the cylindrical base that positions at a distance from the inner side wall of the recipient Figure 3C and 3D show that the line segment joining the circle representing the circular base of the cylinder with the body's horizontal conic intersection with maximum diameter is a straight line 24a, whereas the line segment joining the body's horizontal conic intersection with the pointed tip 31 of the body is an arc of a circle 24b which centre is located at a radius from the body and which convex side is directed towards the body. A further difference exists in the presence of a venting opening in the form of a tube 26 adjacent to and at the height of the inner side wall 9 of the container. The tube reaches through the bottom surface of the container. The tube positions parallel to the outer side wall of the body' s cylinder and is partly enclosed 33 by the cylinder 18.