Liquid dispenser with bellows pump

Abstract

Liquid dispensers (10), in particular for discharging pharmaceutical or cosmetic liquids and which have a liquid store (12) for storing the liquid before discharge and a discharge opening, are known, in which a delivery device in the form of a bellows pump is provided in order to deliver liquid from the liquid store to the discharge opening (22). Measures are proposed for increasing the operational reliability of such dispensers. In order to avoid a disadvantageous orientation of corrugated segments of the bellows of the bellows pump (50), it is proposed to design a first partial segment (68B) in a special form. In order to avoid a valve fault caused by tilting of a valve body, which is an integral part of the bellows, it is proposed to design and orient connecting webs in such a way that they are primarily compressed rather than stretched.

Description

[0001] 0715P0456WO Page 1 March 23, 2026

[0002] Liquid dispenser with bellows pump

[0003] SCOPE OF APPLICATION AND STATE OF THE ART

[0004] The invention relates to the field of liquid dispensers, in particular for dispensing pharmaceutical or cosmetic liquids. Liquids within the meaning of the invention include not only low-viscosity liquids but also, in particular, higher-viscosity liquids such as creams, lotions, or foams.

[0005] Liquid dispensers of the generic type and according to the invention have a liquid reservoir for storing the liquid before dispensing, as well as a dispensing opening to which the liquid is conveyed by means of a conveying device.

[0006] In liquid dispensers of the generic type and according to the invention, the dispensing device is designed as a bellows pump. This means that a bellows is provided, forming a pump chamber whose volume is compressed by the user by means of a manual movement, thereby pushing the contained liquid towards the dispensing opening. During the subsequent return movement, the bellows extends again, drawing liquid from the liquid reservoir, which is then available for the next dispensing.

[0007] A bellows designed for this purpose has two ends, between which a plurality of wave segments are arranged one behind the other. Each wave segment consists of a sub-segment that tapers in the direction of flow and a sub-segment that widens in the same direction. The sub-segments can be sharply defined or blend seamlessly into one another. Bellows used in liquid dispensers typically have between 2 and 7.5 wave segments, and thus between 4 and 15 sub-segments.

[0008] Liquid dispensers with bellows pumps offer several advantages over other pump designs. They require fewer components and are therefore easier to assemble and recycle. In particular, the valve body of an inlet valve can be integrally integrated with the bellows as part of a single bellows assembly. Furthermore, depending on the bellows design, a separate return spring may not be necessary.

[0009] A disadvantage of existing solutions is that various types of malfunctions can occur during use in individual cases. For example, actuating the liquid dispenser and thus compressing the bellows can sometimes cause individual wave segments to twist into an energetically unfavorable shape, making it difficult or delaying the return to their original position. This can be observed particularly in bellows that, as a whole, have a shape that tapers in one direction.

[0010] It has also been observed that strong mechanical impulses can lead to malfunctions of integrated inlet valves in bellows pump dispensers, for example, if the dispenser is dropped. An inlet valve body, which is lifted relative to a valve seat to open the inlet valve, can be deflected by such an impulse to such an extent that it no longer returns to its original position. This can be caused, for example, by demolding geometries designed for simplified demolding during injection molding. The valve body can, for instance, come into interlocking contact with such demolding geometries and therefore cannot return to the closed position. The result is that the bellows pump can no longer pump liquid.

[0011] TASK AND SOLUTION

[0012] The object of the invention is to provide a liquid dispenser of the type mentioned above, which is optimized in particular with regard to its operational safety, especially with regard to continued operational capability after a fall.

[0013] Two measures are proposed for improving such a liquid dispenser, and these are preferably implemented together. However, each measure also results in a liquid dispenser with increased operational reliability when implemented independently.

[0014] A liquid dispenser according to the invention has the generic features of a liquid reservoir including a conveying device in the form of a bellows pump, by means of which the liquid is conveyed from the liquid reservoir to the discharge opening.

[0015] As described at the beginning, the bellows of the bellows pump has two ends, between which a plurality of wave segments are arranged one behind the other. Each wave segment consists of a sub-segment that tapers in the discharge direction and a sub-segment that widens in the discharge direction. Wave segments are understood to be periodic widenings and narrowings, regardless of their specific shape. This includes both bellows with sinusoidal wave segments and bellows with sharply defined boundaries between the sub-segments.

[0016] The first aspect of the invention relates to a design in which the bellows is configured as a tapered bellows. This means that the outer diameter of the shaft segments decreases from a wide bellows end towards a narrow bellows end. In particular, the wide bellows end can represent the outlet end of the bellows, and the narrow bellows end can represent the inlet end. The tapered shape of the bellows can be achieved, in particular, by ensuring that only the first segment on the widened side spans a significantly larger radius change than the other segments.

[0017] The bellows is designed to compress the shaft segments during its contraction in such a way that both sub-segments of a shaft segment are oriented towards the narrow end of the bellows in the compressed state. Orientation towards the narrow end of the bellows means that, with respect to an axial direction or the conveying direction, the respective sub-segments are further axially spaced from the narrow end of the bellows on the outside than on the inside.

[0018] It has been shown that this orientation reduces the risk of the bellows remaining compressed in the area of ​​this shaft segment during a return movement, and thus failing to return to its original position or only doing so with a delay. This risk is greater with a bellows that converges as a single unit than with a cylindrical bellows where the outer diameter of all segments is identical.

[0019] In particular, it has been shown that, to achieve the advantageous behavior, the bellows can have a first sub-segment at its wide end that tapers in circumference towards the narrow end, and whose wall thickness is at least partially greater than the average wall thickness of the bellows' sub-segments. The bellows thus begins at its wide end with a sub-segment that is at least partially thickened.

[0020] Preferably, the average wall thickness of the bellows is less than 0.5 mm, while the first sub-segment has an average wall thickness of at least 0.5 mm at the flared end of the bellows, and in particular an average wall thickness of at least 0.6 mm. The average wall thickness of the first sub-segment is preferably at least 10%, and more preferably at least 20%, greater than the average wall thickness of the subsequent sub-segments. If the last sub-segment opposite the first sub-segment has a different average wall thickness than the other sub-segments, it is not considered in this analysis.

[0021] During compression of the bellows, the inventive design results in the thicker first segment at the expanded bellows end deforming to a comparatively small extent, particularly at the beginning of the compression. The risk of this first segment folding over against its initial orientation is significantly reduced. The thicker first segment preferably deforms to a lesser degree overall than the subsequent segments. Furthermore, the specific design of the first segment, and in particular its non-uniform thickness and / or its decreasing thickness towards the opposite bellows end, ensures that while the thicker first segment does deform, this deformation is less pronounced and does not carry the risk of folding over.

[0022] Towards the end of the bellows' shortening, and thus in its shortened final position, the first segment is still in its original orientation and, in terms of its cross-section, points towards the opposite end of the bellows. Additionally, the second segment is also in an orientation essentially parallel to the first segment in terms of its cross-section, and its inner end, where it transitions into the first segment, is closer to the opposite end of the bellows than its outer end. This second segment has therefore folded over as intended.

[0023] Although the second sub-segment, in its shortened end position and with respect to a cross-section, is usually not parallel to the first sub-segment, it is nevertheless arranged in a fundamentally similar orientation: Both the first sub-segment and the subsequent second sub-segment are thus further away from the tapered bellows end with their outer end with respect to an axial direction than with their respective inner end.

[0024] It has been shown that the described relatively strong change in position of the second sub-segment, which is thinner than the first sub-segment, and its intended folding over, does not cause any problems during the return to its original position, unlike in the case of a folding first sub-segment. Preferably, the described shape of the bellows with a thicker first sub-segment at the narrow bellows end not only enables the described advantageous deformation of the first shaft segment, but also indirectly acts on at least one subsequent shaft segment.

[0025] This can be achieved in particular by ensuring that, when the bellows is fully compressed and thus in its shortened end position, a first bend area adjoining the first tapered segment rests against a segment of the subsequent wave segment. The first wave segment, or rather its bend area, presses against the subsequent wave segment in the direction of the narrow end of the bellows. Preferably, this second wave segment assumes a shape similar to the preceding first wave segment, with both segments of the second wave segment oriented towards the narrow end of the bellows. In the compressed state of the bellows, the first four segments are therefore parallel with respect to their cross-section, i.e., in a fundamentally identical orientation.

[0026] In particular, preferably, this can also affect more than one further wave segment, by the kinking regions of several wave segments pressing down the next wave segment.

[0027] The shortened end position, to which the above statements refer, is understood to be the degree of compression that occurs when other donor components prevent further compression or when the force required for operation makes it obvious to the user that further operation is not intended.

[0028] Preferably, the first tapered sub-segment described above has a pelvic forest which has a decreasing wall thickness in the direction of the narrow pelvic end, wherein this tapering occurs in stages or continuously.

[0029] It has been shown that a constant wall thickness on the first segment can have a detrimental effect, depending on the bellows geometry. If the uniform wall thickness is too great, there is little or no deformation at the beginning of bellows compression, and there is a risk that, under heavy compression, the first segment will fold towards the wider end of the bellows, making it difficult for it to return to its original position. A decreasing wall thickness from the wider end of the bellows towards the narrower end achieves the ideal deformation behavior. This design of the first segment, with its decreasing wall thickness away from the wider end, results in advantageous behavior during compression. Compression initially leads to deformation of the first segment at the transition to the second segment, and only later and to a lesser extent to deformation at the other end of the first segment.

[0030] The second aspect of the invention, which is preferably implemented in combination with the first aspect of the invention, also relates to a generic liquid dispenser with a conveying device designed as a bellows pump.

[0031] A special feature here is that the bellows is part of a single-piece bellows component, which also includes an inlet valve body. This inlet end of the bellows is connected to a surrounding bellows base via deformable connecting webs. These connecting webs are elastically deformed to open the valve and then apply a force to the valve body, returning it to its closed position.

[0032] In particular, two opposing connecting bridges can be provided, or three or four connecting bridges distributed around the circumference of the valve body, preferably spaced uniformly apart from each other.

[0033] To ensure that the valve body does not enter a position in which the valve no longer closes properly, the connecting webs are arranged in such a way that they are primarily compressed when the inlet valve body is deflected during the opening of the inlet valve.

[0034] A deformation of the connecting webs is described as a deformation primarily characterized by compression if the energy stored in the deformed state in the valve webs arises predominantly from compression and to a lesser extent from elongation. It is preferred that the connecting webs have a curved shape, such that the deflection of the valve body also causes a mutually reinforcing bending of the connecting webs, which is accompanied by external elongation and internal compression. In this case as well, the proportion of the stored energy is due more to compression and to a lesser extent to elongation.

[0035] The advantage of compressive deformation over tensile deformation lies in the fact that compressive deformation results in a stronger counterforce and, in principle, sets a greater limit to the deformation than tensile deformation, beyond which further deformation is hardly possible. Furthermore, the risk of damage during compressive deformation is generally lower than during tensile deformation, as there is no risk of a tensile crack.

[0036] The deflection is limited by the compression stress on the valve stems when the valve opens. Specifically, this limiting of deflection has no restrictive effects during normal use, but prevents the valve body from moving into an unintended position in the event of high-impulse impacts, such as when the liquid dispenser is dropped.

[0037] In particular, a geometry can be achieved where the deformation upon opening the valve is primarily compressive if the connection of the connecting webs to the bellows base is offset relative to the connection of the connecting webs to the inlet valve body. The connection to the bellows base is offset in the opening direction relative to the connection on the inlet valve body when the valve is closed. When the valve is opened, the distance between the connections shortens and the connecting webs are compressed.

[0038] A bellows component for a liquid dispenser of the described type may preferably have a demolding geometry that serves to couple a force in the axial direction during demolding. The demolding geometry is usually provided on an inner surface of the bellows component. Omitting such a demolding geometry is disadvantageous in practice. However, such a demolding geometry represents a potential hazard that can make it difficult for the valve body to return to the closed position after a force impulse.

[0039] To prevent this, it is proposed that a clear cross-section surrounded by the demolding geometry have an inner diameter that is at least 10% larger than the outer diameter of the inlet valve body, preferably at least 20% larger.

[0040] A particularly preferred design is one in which the demolding geometry has at least two separate demolding ribs, between which one of the connecting ribs of the inlet valve body is positioned. For example, three demolding ribs can be provided, each spanning approximately 90° of the circumference, with three 30° gaps between them through which the connecting ribs extend or in which the connecting ribs are connected to the bellows base. A design with four connecting ribs can also be advantageous. If the described decoupling geometry is at the same level as the connection of the connecting ribs to the bellows base, the risk is very low that the valve body could compress the connecting ribs to such an extent that the valve body could become entangled with the decoupling geometry.

[0041] It has proven advantageous to provide decoupling grooves between the demolding ribs and the connecting ribs. This simplifies manufacturing and improves the opening behavior of the inlet valve.

[0042] BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Further advantages and aspects of the invention will become apparent from the claims and from the following description of preferred embodiments of the invention, which are explained below with reference to the figures.

[0044] Fig. 1 shows a liquid dispenser according to the invention in overall view.

[0045] Figures 2 and 3 show a bellows component of the liquid dispenser in perspective and cutaway views.

[0046] Figures 4A to 4E illustrate the deformation of a bellows of the bellows component during a dispenser actuation.

[0047] Figures 5 and 6 show, in cutaway views, the structure of an inlet valve of the liquid dispenser.

[0048] Figures 7A to 7C illustrate the relative movement of an inlet valve body of the inlet valve in the closed state, in the intended open state, and at maximum deflection during a force impulse.

[0049] DETAILED DESCRIPTION OF THE EXECUTION EXAMPLES

[0050] Fig. 1 shows a liquid dispenser 10 according to the invention in a sectional view. The liquid dispenser 10 has a liquid reservoir 12 and a dispensing head 14 mounted on and locked to the reservoir. The dispensing head 14, in turn, has a base component 15, which is attached to the liquid reservoir 12, in particular a locking mechanism, and an actuating push button 16, which has a push surface 16A on its upper side for manual actuation. A dispensing opening 22 is provided on the actuating push button 16.

[0051] The liquid dispenser 10 can be used, for example, for dispensing liquids for personal care.

[0052] To dispense liquid, the actuating push button 16 is pressed downwards in actuation direction 2A via the actuating surface 16A.

[0053] The discharge head 14 has a pumping unit 50. This pumping unit 50 is designed as a bellows pump. It has a bellows component 60, which, in the manner typical for bellows pumps, has a flexible wall 54 forming a bellows 62 and consisting of individual shaft segments 66. The shaft segments 66 have one segment that widens in the conveying direction 2B and one that narrows in the conveying direction 2B. Bend areas 69 are provided between each of the segments. Depending on the type of bellows component 60, the bend areas 69 can be acute-angled or rounded.

[0054] The part surrounded by the bellows 62 forms the pump chamber 52 of the liquid dispenser 10.

[0055] The bellows component 60 has a bellows base 72 at the inlet end 70 of the bellows 62, by means of which it is attached to the base component 15 of the liquid dispenser. For this purpose, it is held in place by frictional or positive locking by retaining walls of the base component 15. At the opposite outlet end 80 of the bellows 60, a bellows end ring 73 is attached to the bellows 60, which is positively or forcefully fastened to the actuating pressure 16.

[0056] The flexible wall 54, which forms the actual bellows 62 of the bellows component 60, has a shape that widens upwards and thus in the conveying direction 2B. This means that an upper end of the bellows 62 at the discharge end 80 has a larger diameter than the outer diameter of the lowest bellows segment at the inlet end 70.

[0057] The pump assembly 50 has two valves: an inlet valve 90 and an outlet valve 96. The inlet valve 90 opens in the event of negative pressure in the pump chamber 52 relative to the fluid reservoir 12. The outlet valve 96 opens in the event of positive pressure in the pump chamber 52 relative to the external environment. The inlet valve 90 has an inlet valve body 92, which, like the bellows 62, is formed by the one-piece bellows component 60. The inlet valve body 92 is connected to the bellows base 72 via a total of three connecting webs 94. An alternative design, which is sometimes preferred, includes four or even five connecting webs instead. In the event of negative pressure in the pump chamber 52, this inlet valve body 92 is lifted and thereby loses contact with a counter surface 15A on the base component 15. This will be explained in more detail below.

[0058] The outlet valve 96 is located between the pump chamber 52 and the discharge opening 22. Its design is not relevant to the present invention.

[0059] When the user presses down the actuating button 16, the bellows 62 shortens until the end position of the actuation is reached. This occurs when the actuating button's skirt abuts a counter surface of the base component 15.

[0060] The shortening of the bellows is accompanied by a reduction in the volume of the pump chamber 52. The liquid already present in the pump chamber 52 is pressurized, which closes the inlet valve 90 and opens the outlet valve 96. Liquid is discharged through the discharge opening.

[0061] When the actuating button is released, it returns to its original position. In the present design, this occurs primarily due to the spring tendency of the bellows 62, which was elastically deformed during actuation. Additionally, a separate return spring can be provided, located on the outside of the bellows 62 between the base component 15 and the actuating button 16.

[0062] During the return movement, the outlet valve 96 is closed, while the inlet valve 90 opens, allowing fluid to flow into the pump chamber 52 through an opening 15B in the base component 15.

[0063] Figures 2 and 3 show the bellows component 60 in separate views. Figure 2 shows the bellows component in a perspective view. Figure 3 shows a sectional view.

[0064] As explained above, the lower end of the bellows component 60 is formed by a bellows base 72, which is designed to be attached to the base component 15 of the discharge head 14.

[0065] The inlet valve body 92 of the inlet valve is surrounded by the bellows base, and three connecting webs 94 are provided that connect the bellows base 72 and the inlet valve body 92. As can be clearly seen from Fig. 3, the connecting webs are located far outwards and thus relatively far down on one upper surface of the inlet valve body 92. On the bellows base, the connecting webs 94 are located far up, immediately in front of the transition between the bellows base 72 and the actual bellows 62.

[0066] As can also be clearly seen in Fig. 3, inwardly pointing webs of a demolding geometry 74 are provided on the inside of the bellows base 72. In this case, there are a total of three webs, with the connection between the connecting webs 94 and the bellows base 72 being arranged in gaps between these webs of the demolding geometry 74.

[0067] Furthermore, it is clearly visible in Fig. 3 that the bellows wall has a non-uniform thickness. The uppermost and thus, with respect to the conveying direction 2B, the last shaft segment 66 consists of two sub-segments 68A and 68B with significantly different shapes. With respect to the conveying direction, sub-segment 68A is considerably longer than the subsequent sub-segments in the largely relaxed bellows state shown in Fig. 3. The bellows has a total of five sub-segments 68A to 68E, with the first four sub-segments 68B to 68E in the conveying direction 2B having an approximately uniform wall thickness. However, the last sub-segment 68A in the conveying direction 2B has a greater wall thickness, at least in some sections. In the present case, the wall thickness of the last sub-segment is designed to increase in the conveying direction 2B and, at the end and shortly before the transition to the upper end ring 73 of the bellows component 60, has approximately twice the thickness of the first four sub-segments.

[0068] Figures 4A to 4E explain the purpose of this design of the sub-segments 68A to 68E and the deformation of the bellows 62 of the bellows component achieved by this design.

[0069] The special design of the sub-segments 68A to 68E primarily serves the purpose of preventing the bellows 62 from failing to return to its original starting position as shown in Fig. 3 after actuation. It was determined that this failure, which can occur particularly after very forceful actuation, can be influenced especially by the design of the sub-segment 68A with the largest outer diameter.

[0070] Fig. 4A shows the unactuated initial state. From this point, the axial compression of the bellows 60 takes place. As the intermediate state of Fig. 4B shows, the first sub-segment 68A initially remains largely undeformed. It only buckles slightly. In this first phase, the main load of the deformation is primarily borne by the third and middle sub-segment 68C, 68D.

[0071] The continued deformation into the intermediate state shown in Fig. 4C is accompanied by the fact that the third sub-segment 68C temporarily flips over. This means that the kinks at both ends of sub-segment 68C reach at least the same height, and that the second and third sub-segments 68B and 68C, as viewed from the bellows end ring 73, are now in an almost parallel alignment, with their respective outer diameters positioned below their respective inner diameters in relation to the figures. The auxiliary lines 4 in Fig. 4C illustrate this.

[0072] The continued movement leads to the intermediate state shown in Fig. 4D. The low deformability of the first sub-segment 68A now causes the inner end of the first sub-segment to further compress the second and third sub-segments 68B, 68C, so that they now lie largely parallel and horizontally against each other.

[0073] From this intermediate position shown in Fig. 4D, continued actuation causes the first segment 68A to push the bend 69 between the second segment 68B and the third segment 68C further downwards, so that ultimately, in the final position shown in Fig. 4E, several segments 68A, 68B, 68C, 68D, or even all segments, are aligned approximately parallel to each other. This means that their inner end, relative to the conveying direction 2B, is positioned below their outer end. Lines 6 illustrate this.

[0074] The compressed position shown in Fig. 4E has proven to be an ideal condition for reliable return to its original position. When the actuating force acting on the bellows 62 is removed, the bellows reliably returns from its position in Fig. 4E to the position shown in Fig. 4A.

[0075] The operation of the inlet valve 90 is explained in more detail with reference to Figures 5 to 7B. The construction of the bellows component 60 in the area of ​​the inlet valve 90 is further explained with reference to the sectional, perspective views in Figures 5 and 6.

[0076] Figures 5 and 6 show that the inlet valve body 92 has the shape of a downwardly open hood, the inner contour of which corresponds approximately to that of a hemisphere. A lower edge forms the sealing edge 93 of this hood shape. The inlet valve body 92 is connected to the bellows base 72 via the previously mentioned connecting webs 94. On the side of the inlet valve body 92, these connecting webs 94 extend from the outer edge of the top surface. The connecting webs 94 themselves have a curved shape. The opposite end of the connecting webs 94 is located in the region of an upper end of the bellows base 72. These ends of the connecting webs are positioned between a total of three webs of a demolding geometry 74, with the connecting webs 94 being separated from the webs of the demolding geometry 74 by decoupling grooves 76.

[0077] The design of the connecting webs 94 is specifically chosen to prevent malfunctions at the inlet valve 90. Such malfunctions can occur particularly if the liquid dispenser 10 is subjected to a strong mechanical impact, especially if the liquid dispenser 10 falls to the ground.

[0078] The described design counteracts this: As can be seen from Figs. 7A and 7B - which show the closed state of the inlet valve 90 with sealing edge 93 in contact with a counter surface 15C in Fig. 7A and the intended open state of the inlet valve in Fig.

[0079] As shown in Figure 7B, a displacement of the inlet valve body 92 upwards in the opening direction 2C is primarily accompanied by a compression of the connecting web 94. This compression is caused by the shortening of the axial distance between the respective connection points on the inlet valve body 92 and on the bellows base 72.

[0080] Due to the curved shape of the connecting webs 94, some of the deformation does occur through bending deformation, and thus through a combined tensile and compressive deformation. However, the majority of the energy stored in the connecting webs in the deformed state is stored through compression.

[0081] Fig. 7C shows a condition that is not reached during normal operation, but can only be reached by a hard impact on the liquid dispenser. Even in such a situation, the inlet valve body 92 can only deflect upwards to a limited extent. The strongly compressed connecting webs 94 exert a strong counterforce and thus prevent the inlet valve body 92 from being deflected beyond the position shown in Fig. 7C. In particular, the edge of the inlet valve body 92 is still below the upper surface of the webs of the demolding geometry 74 in this situation, so there is no risk of it jamming.

Claims

Patent claims 1. Liquid dispenser (10), in particular for dispensing pharmaceutical or cosmetic liquids, with the following features a. The liquid dispenser (10) has a liquid reservoir (12) for storing the liquid before dispensing, and b. the liquid dispenser (10) has a dispensing opening (22) for dispensing liquid, and c. the liquid dispenser (10) has a conveying device (50) for conveying liquid from the liquid reservoir to the discharge opening, and d. the conveying device (50) is designed as a bellows pump and has a pumping chamber (52) that is at least partially bounded by a bellows (62) oriented in a bellows extension direction, wherein, for the purpose of conveying liquid, a shortening of the bellows (62) in the bellows extension direction and thus a reduction of the volume of the pumping chamber (52) can be effected, and e. the bellows (62) has two ends (70, 80) between which a plurality of wave segments (66) arranged one behind the other are provided, each consisting of a segment tapering in the discharge direction and a sub-segment widening in the discharge direction (68A, 68B, 68C, 68D, 68E), characterized by the following additional features: f. the bellows (62) is designed as a tapered bellows (62), wherein the outer diameter of the shaft segments (66) decreases from a wide bellows end (80) towards a narrow bellows end (70), and g. the bellows (62) is designed to compress the shaft segments (66) when it shortens, such that both sub-segments of a shaft segment are oriented towards the narrow bellows end (70) in the compressed state, and i.e. to achieve this behavior the bellows (62) has at its wide end (80) a first sub-segment (68A) that tapers towards an outer diameter of the narrow bellows end, the wall thickness of which is at least section by section greater than the average wall thickness of the sub-segments of the bellows (62).

2. Liquid dispenser (10) according to claim 1 with the following further feature: a. the wide bellows end (80) represents the outlet end of the bellows (62) and the narrow bellows end (70) represents the inlet end of the bellows (62).

3. Liquid dispenser (10) according to one of claims 1 to 2 with the following further feature: a. when the bellows (62) is fully compressed, a first bending area (69) adjoining the first tapered sub-segment (68A) lies against a sub-segment (68B) of the subsequent wave segment (66).

4. Liquid dispenser (10) according to one of the preceding claims with the following further feature: a. a bellows wall (54) in the area of ​​the first tapering sub-segment (68A) tapers towards the narrow bellows end (70), whereby this tapering occurs stepwise or continuously.

5. Liquid dispensers (10), in particular for dispensing pharmaceutical or cosmetic liquids, with the following features a. The liquid dispenser (10) has a liquid reservoir (12) for storing the liquid before dispensing, and b. the liquid dispenser (10) has a dispensing opening (22) for dispensing liquid, and c. The liquid dispenser (10) has a conveying device (50) for conveying liquid from the liquid reservoir (12) to the discharge opening (22), and d. the conveying device (50) is designed as a bellows pump (50) and has a pump chamber (52) that is at least partially bounded by a bellows (62) oriented in a bellows extension direction, wherein, for the purpose of conveying liquid, a shortening of the bellows (62) in the bellows extension direction and thus a reduction of the volume of the pump chamber (52) can be effected, and e. the bellows (62) has two ends (70, 80) between which a plurality of wave segments (66) arranged one behind the other are provided, each consisting of a segment tapering in the discharge direction and a sub-segment widening in the discharge direction (68A, 68B, 68C, 68D), characterized by the following additional features: f. The bellows (62) is part of a one-piece bellows component (60), which also includes an inlet valve body (92) of an inlet valve (90), which is connected at an inlet end (70) of the bellows (62) to a surrounding bellows base (72) by means of deformable connecting webs (94) and is deflectable under elastic deformation of the connecting webs (94) in the direction of the opposite outlet end (80) of the bellows (62) in order to open the inlet valve (90), and g. the connecting webs (94) are arranged such that they are primarily compressed when the inlet valve body (92) is deflected during the opening of the inlet valve (90).

6. Liquid dispenser (10) according to claim 5 with the following further feature: a. The connection of the connecting webs (94) to the bellows base (72) is axially offset in the direction of the opposite outlet end (80) compared to the connection of the connecting webs (94) to the inlet valve body (92).

7. Liquid dispenser (10) according to claim 5 or 6 with the following further features: a. in the area of ​​the bellows base (72) the bellows component (60) has a demolding geometry (74) on which the bellows component (60) can be subjected to force for the purpose of demolding from an injection molding tool, and b. a clear cross-section surrounded by the demolding geometry has an inner diameter that is at least 10% larger than the outer diameter of the inlet valve body, preferably at least 20% larger.

8. Liquid dispenser (10) according to one of claims 5 to 7 with the following further feature: a. at least two connecting bridges (94) are provided, preferably with one of the following additional features: b. at least three connecting bridges (94) are provided, and / or c. the connecting webs (94) are uniformly spaced and distributed around the circumference of the inlet valve body (92).

9. Liquid dispenser (10) according to one of claims 5 to 8 with the following further features: a. in the area of ​​the bellows base (72) the bellows component (60) has a demolding geometry (74) on which the bellows component (60) can be subjected to force for the purpose of demolding from an injection molding tool, and b. the demolding geometry (74) has at least two separate demolding ribs, between which a connecting rib (94) is placed.

10. Liquid dispenser (10) according to claim 9 with the following further feature: a. Decoupling grooves (76) are provided between the demolding ribs and the connecting ribs (94).

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