Pump dispenser with a pump device that can be attached to the underside

Abstract

Dispenser for portioning liquid to pasty masses (M) with a storage container (1) and a dispensing opening (2) arranged at the top of the storage container (1) for dispensing the mass (M), and with a pumping device (3) which interacts with a piston (4) arranged inside the storage container (1), which, when the pumping device (3) is actuated, can be displaced from bottom to top on an inner surface (5) of the storage container (1), characterized in that the pumping device (3) is arranged below the piston (4).

Description

field of technology The invention relates to a dispenser for portioning liquid to pasty masses, comprising a storage container and a dispensing opening arranged at the top of the storage container for dispensing the mass, and a pumping device which interacts with a piston arranged inside the storage container, which, when the pumping device is actuated, can be moved from bottom to top on an inner surface of the storage container. State of the art A pump dispenser of this type is known from DE 20 2005 019 298 U1. This patent discloses a dispenser for the positioned dispensing of liquid to pasty masses. The dispenser has a dispensing head designed as a pump head, which is telescopically arranged on an upper section of the dispenser. The pumping device is located at the top, essentially inside the dispensing head of the dispenser. By vertically displacing the dispensing head, the mass can be dispensed through a dispensing opening located on the dispensing head. To close the dispensing opening after use, a captive closure element is provided, which is permanently attached to the dispensing head. The closure element is designed as a linearly movable sliding element. In the closed position of the sliding element, a free end of a closure pin located inside the dispensing head engages in a dispensing opening of the sliding element. In pump dispensers known from the prior art, where the pump mechanism is located at the top of the reservoir, small amounts of air can enter the reservoir containing the dispensed product. This can lead to oxidation of the product in the reservoir. For example, this can cause undesirable discoloration of creams containing vitamin C. Summary of the invention The invention is based on the objective of further developing a pump dispenser in a way that is advantageous for use and, in particular, of providing means by which the penetration of air into a storage container of a pump dispenser containing a mass to be dispensed is prevented, or at least inhibited. The problem is solved by the device specified in the claims. The dependent claims not only represent advantageous further developments of the technical teachings specified in the dependent claims, but are also independent solutions to the problem. First and essentially, it is proposed that the pumping device be arranged at the bottom of the pump dispenser's reservoir. "Bottom" here refers to the end of the reservoir opposite the end where the dispensing opening is located. The dispensing opening is located at the top of the pump dispenser. A piston can be arranged inside the reservoir, which interacts with the pumping device. When the pumping device is actuated, the piston is moved from bottom to top, sliding along a sealing inner surface of the reservoir. The piston pushes the mass stored within the reservoir upwards, dispensing a portion of the mass through the dispensing opening at the top of the reservoir. The pumping device can be arranged below the piston, thus pressurizing it from below.No suction is created. It is specifically designed that the pump device can be detachably attached to a lower end section of the storage container. The pump device can be detachably attached to the lower end section of the storage container in such a way that it can be reused after being separated from the dispenser. For example, the pump device can be attached to the lower end section of the storage container by means of a threaded connection. For example, the lower end section can have an internal thread into which an external thread formed by the pump device can be screwed. The pump device can be arranged telescopically on the underside of the storage container for dispensing the substance to be dispensed. A volume can be arranged between the bottom of the reservoir and the piston, into which a propellant can be injected when the pumping device is activated. The pumping device can include a pump to inject the propellant into this volume. The pump can be, for example, a conventional pressure pump. The propellant can be a gas, such as air, or a liquid. Water, in particular, can be used as a propellant. Injecting the propellant into the volume creates an overpressure that pushes the piston upwards. A reservoir can be detachably attached to the pump, forming a propellant storage volume in which the propellant can be stored. The reservoir can be accessible so that a user can fill it with water independently. The propellant storage volume can have an opening through which the propellant can be fed into it. The opening can be located, for example, at the lower end of the propellant storage volume, i.e., at the end furthest from the storage container when attached. The filling opening can be resealable, allowing a user to refill the propellant storage volume as needed. The propellant storage volume can be equal to or greater than the volume of the storage chamber. An adapter part may be provided with which the pump body telescopically interacts. The adapter part may be detachably attached to the pump, for example, with a snap or locking connection. The reservoir, in turn, may be detachably attached to the adapter part, for example, by means of a screw connection. The piston can be pot-shaped, with the bottom of the pot-shaped piston body facing upwards when installed in the reservoir and an opening opposite the bottom facing downwards. The piston body can enclose a constructive volume that is bounded upwards by the bottom, laterally by a wall of the piston (which is particularly cylindrical), and downwards by a downwardly projecting free end of the piston wall. The piston body has an opening opposite the bottom. This opening has an opening area that is bounded radially outwards by the downwardly facing end of the piston wall. The downwardly facing end of the piston wall is the lower boundary of the constructive volume enclosed by the piston. The piston body wall can form a gas-tight seal against the inner wall of the reservoir's storage chamber. In the piston's initial position, which it assumes before the first pump actuation, a base formed by the bottom of the reservoir projects into the volume enclosed by the piston. In this initial position, the downward-facing end of the piston body wall can rest on the bottom of the reservoir. In this lower position, no pressure is yet exerted on the piston; that is, no propellant has yet been introduced into the volume between the piston and the bottom of the reservoir.Due to the base projecting into the structural volume enclosed by the piston, the free volume enclosed by the piston body for receiving the propellant is smaller than the free volume enclosed by the piston in an upper displacement position where the base no longer projects, or only partially projects, into the structural volume. In the initial position, an upward-facing end face of the base may be spaced from the bottom of the piston. The base may be substantially cylindrical, although it may also have another shape. The cross-sectional area of ​​the base may be smaller than the cross-sectional area of ​​the reservoir, so that a side wall of the base is spaced from the inner wall of the reservoir, and a recess extending coaxially around the base is arranged between the base and the inner wall of the reservoir.This recess may be bounded below by the base of the reservoir. In its initial position, the piston wall may protrude at least partially into the recess. After one or more pump actuations, the piston wall may be completely displaced from the recess into the upper displacement position, in which the base is entirely outside the structural volume. An inlet opening can be arranged in the upward-facing end face of the base, through which the propellant can be pumped into the volume located between the piston and the bottom of the reservoir or the end face of the base. The base forms an insertion recess between its upward-facing and downward-facing end faces, into which an end section of the pump body can be inserted. The end section of the pump body can be detachably fastened in the insertion recess, for example, by means of a screw connection. When inserted, an upper outlet opening of the pump can open into the inlet opening of the base, so that the propellant flowing through a pump chamber formed by the pump during pump actuation can flow into the volume between the piston and the bottom of the reservoir.The amount of liquid stored in the propellant volume can be selected such that, during a pumping operation, the sealing surface between the piston wall and the inner wall of the reservoir is hermetically sealed by the liquid. After a pumping operation, the liquid level within the depression located between the base and the inner wall of the reservoir can be positioned axially above the downward-facing end face of the piston wall. This prevents any air that may be present within the volume between the piston and the bottom of the reservoir from entering the reservoir through the sealing surface between the piston wall and the inner wall of the reservoir. The upper end section of the pump can be inserted into the insertion cavity through an opening located in the downward-facing end face of the base. This opening in the downward-facing end face of the base can be larger than the inlet opening located in the upward-facing end face of the base. The piston can be arranged centrally around a dispenser axis. Preferably, the piston's extension length is greater than the height of the base, so that the volume between the piston and the base or bottom of the reservoir is sufficient to allow the propellant to be injected during a pumping operation to push the piston upwards. A lid can be provided to close the dispensing opening located at the top of the pump dispenser. When the pump dispenser is not in use, the lid can be detachably attached to a lower end section of the reservoir. For example, the lid can have an internal thread that can be screwed onto an external thread formed by the lower end section of the reservoir. After the pump dispenser has been opened, the lid can be detachably attached to the upper end section of the reservoir to close the dispensing opening located there. The upper end section of the reservoir can also have an external thread onto which the lid can be screwed. The lid can have a locking pin on the inside of its base, facing the upper end of the reservoir, which, when closed, engages in the dispensing opening to create a seal. The storage container can have an upper opening which, after the storage chamber is filled with the substance, can be sealed gas-tight by means of a lid plate. The lid plate can, for example, be gas-tightly welded to the housing of the storage container using ultrasound. The dispensing opening can be located within the lid plate. The dispensing opening can, for example, be sealed, with the seal being broken by a user upon first use. The housing of the storage container can be made of polyethylene terephthalate (PET), for example. However, the storage container itself can also be made of a different material, particularly another type of plastic. The adapter part can be made of polyethylene (PE), for example. The lid plate can be ultrasonically welded to the PET storage container. The lid can be made of PET or PE, for example. However, the individual components can also be made of another suitable material. Such a pump dispenser according to the invention is suitable for masses of varying viscosities. This can range from a water-like liquid to a very highly viscous, thick mass. Brief description of the drawings Exemplary embodiments of the invention are explained below with reference to the accompanying drawings. These show: Fig. 1 a sectional view of the pump dispenser according to the invention with a pump device 3 arranged below a piston 4 for dispensing a mass M stored in a reservoir 1, the pump device being detachably attached to the reservoir 1, wherein a reservoir 8 providing a propellant T is detachably attached to the pump device 3, and wherein a lid 17 is screwed onto an upper end section of the reservoir; Fig. 2 a partial view of a lower end section of the reservoir 1 of the pump dispenser with the piston 4 in a starting position before a first pump actuation of the pump device; Fig. 3 a sectional view according to Fig. 2, wherein the piston 4 has been pushed upwards into a displacement position by the propellant T pumped upwards by the pumping of the pump device 3.Fig. 4 shows a sectional view of the reservoir 1 with the lid 17 detachably attached to the lower end section, wherein the dispensing opening 2 arranged at the upper end section is closed by means of a seal 25 which is to be broken upon first use of the pump dispenser; Fig. 4a shows a top view in direction IVa in Fig. 4 of the dispensing opening 2 closed by the seal 25 on the front face of the upper end section of the reservoir 1; Fig. 5 shows a sectional view of the reservoir 1 according to Fig. 4, wherein the lid 17 has been unscrewed and the seal 25 has been removed; Fig. 6 shows a sectional view of the pump device 3 with the reservoir 8 detachably attached to the pump 6; Fig. 7 shows an enlarged view of section VII in Fig. 6; and Fig. 8 shows a section along line VIII-VIII in Fig. 6. Description of the embodiments Fig. 1 shows a schematic sectional view of the pump dispenser according to the invention. The pump dispenser comprises a reservoir 1 forming a storage chamber 16, in which a piston 4 is arranged centrally around a dispensing axis a. A mass M to be dispensed is stored within the reservoir 16 and can be dispensed from a dispensing opening 2 located at an upper end section of the pump dispenser when the piston 4 is actuated. When the pump is actuated, the piston 4, which slides from bottom to top along the inner surface 5 of the reservoir 16, interacts with a pump device 3 detachably attached to a lower end section of the reservoir 1. The pump device 3 comprises an adapter part 20 and a pump body 6, which are telescopically connected to one another. A pump 6', shown here only with dashed lines, is arranged within the pump body 6.The pump 6' is a conventional pressure pump. Therefore, a detailed description of its construction has been omitted. To extract the mass M to be dispensed, the pump body 6 is designed to telescopically engage with the adapter part 20, which is detachably attached to a lower end section of the reservoir 1, when the pump is actuated. The adapter part 20 has an external thread at one end facing the reservoir 1 when connected, which is screwed into an internal thread formed by the lower end section of the reservoir 1. The base 22 of the reservoir 1 forms a base 21 projecting upwards into the reservoir chamber 16. The base 21 forms an insertion recess 28 extending between an upper opening 18 and a lower opening 27, in which the upper end section of the adapter part 20 can be detachably attached.The adapter part 20 extends a pump chamber 19 formed by the pump body 6, through which a propellant T can be fed into a volume 7 located between the piston 4 and the bottom 22 of the reservoir 16 when the pump is actuated. The propellant T, supplied by a reservoir 8 detachably attached to the pumping device 3, is fed upwards through the pump chamber 19 into the volume 7 via an inlet opening 10 located at the upper end of the adapter part 20 when the pump is actuated. The propellant T fed into the volume 7 exerts a vertical upward pressure on the piston 4, causing it to move from bottom to top, thereby dispensing at least a portion of the mass M from the outlet opening 2. The pump can be actuated by applying downward vertical pressure to the reservoir 1. The pump device 3 can be placed on a preferably flat surface. The downward vertical manual pressure on the reservoir 1 pushes it downward onto the adapter part 20, which is then telescopically pushed into the pump body 6 against the force of a spring element 36. This forces a portion of the propellant T from the pump chamber 19 into the volume 7 located between the piston 4 and the bottom 22 of the reservoir 1, thereby moving the piston 4 from bottom to top. When the reservoir 1 is subsequently pulled upward, the adapter part 20, and thus the reservoir 1, is moved upward by the force of the spring element 36, and a portion of the propellant T is drawn from the propellant storage volume 9 into the pump 6'.Not shown are valves arranged at an upper and a lower end of the pump 6', wherein the upper valve opens when the reservoir 1 or the adapter part 20 is pushed down and the lower valve closes, wherein when the reservoir 1 is subsequently pulled up the upper valve is closed and the lower valve is open to allow the propellant T to enter the pump 6'. A lid 17 is detachably attached to an upper end section of the storage container 1. The lid 17 has an internal thread 13, which is screwed onto an external thread 14 formed by the upper end section of the storage container 1. A locking lug 23 is arranged on the bottom of the lid 17, which, when screwed on, projects into the dispensing opening 2 and seals it gas-tight. The dispensing opening 2 is located within a sealing plate 24, which is gas-tightly welded to the housing of the storage container 1 by means of ultrasound. The dispensing opening 2 is preferably located in the center of the disc-shaped plate 24. After use of the pump dispenser, the lid 17 can be screwed onto the upper end of the storage container 1 to close the dispensing opening 2. Fig. 2 shows the piston 7 in its initial position before the first pump actuation. The piston 7 is cup-shaped with an upward-facing base 30 and a downward-facing opening 29, with a peripheral surface of the piston wall 15 surrounding the downward-facing opening 29 resting on the base 22 of the reservoir 16. In its initial position, the piston 7 encloses the free volume V0, which is bounded upwards by the base 30 of the piston 4, laterally by the piston wall 15, and downwards by the base 22 of the reservoir 6 and the end face of the base 22. Fig. 3 shows the piston 7 in an upper displacement position after one or more pump actuations, whereby a portion of the propellant T supplied by the reservoir 8 has been fed into the volume 7. In the displacement position, the piston 4 encloses a free volume V1, which is available to receive the propellant T. The free volume V1 enclosed by the piston 4 in the upper displacement position is larger than the free volume V0 enclosed by the piston 4 in the initial position of the piston 4 shown in Fig. 2. This difference in volume is due to the base 21 formed by the bottom of the reservoir chamber 6 of the storage container 1, which projects into the constructive volume enclosed by the piston in the initial position of the piston 4. The constructive volume corresponds to the free volume V1 enclosed by the piston 4 in Fig. 3, which is bounded above by the bottom of the piston 4 and laterally by the piston wall 15.The lower boundary 35 of the free volume V1, which here also corresponds to the constructive volume, is shown with a dashed line. The lower boundary 35 lies within a horizontal surface enclosed by the downward-facing opening 29 of the base 21. The lower boundary 35 of the constructive volume is formed by the lower end of the piston 4 or the piston wall 15. According to the invention, the ratio of the free volume V0 in the initial position to the volume V1 in the upper displacement position (V0 / V1) of the piston 4 is less than 1. The volume ratio V0 / V1 is selected such that, after a first pump actuation, the propellant T gas-tightly seals a sealing surface 26 arranged between the piston wall 15 and the inner surface 5 of the reservoir chamber 6, so that any air present within the volume 7 before the first pump actuation is not pumped through the sealing surface 26 into the reservoir chamber 6. The propellant T can be a liquid, for example, water. The liquid level after the first pumping operation is vertically above the downward-facing end section of the piston wall 15.The volume quotient V0 / V1 is set such that the edge of the piston wall 15, which limits the downward-pointing pot opening 29 radially outwards, is covered by the propellant T in the upper displacement position of the piston 4. Fig. 4 shows the storage container 1 with a lid 17 screwed onto its lower end section. The lower end section of the storage container 1, like the upper end section, forms a fastening element for the detachable attachment of the lid 17. This fastening element is, by way of example, an external thread 12 formed by the lower end section of the storage container 1. To seal the dispensing opening 2 gas-tight until the pump dispenser is used for the first time, a tamper-evident seal 25 is provided, which is shown by way of example in Figs. 4 and 4a. The tamper-evident seal 25 can be manually broken by a user of the pump dispenser before first use. The tamper-evident seal 25 can be made of the same material as the sealing plate 24. The tamper-evident seal 25 is not reusable after being broken. In Figs. 4 and 4a, the tamper-evident seal 25 is shown.Figure 4a shows the sealing closure 25 as an elongated, key-shaped flat body. However, the sealing closure 25 can also be designed differently, for example as a peelable, foil-like closure. Fig. 5 shows the storage container 1 without the lid 17. The lid 17 can also be attached to the end sections of the storage container 1 by means of a detachable connection other than a screw connection, for example a snap connection. Figures 6 and 7 show the pumping device 3 with a detachably attached reservoir 8. The adapter part 20 is inserted into the pumping chamber 19 of the pump body 6. The outer wall of the cylindrical adapter part 20 forms radially projecting projections 32 that engage in longitudinal grooves 31 formed by the inner wall of the pumping chamber 19 and prevent the adapter part 20 from twisting or slipping relative to the pump body 6 in the horizontal direction (see Figure 8). To limit the upward displacement of the adapter part 20 in the vertical direction, at least two locking lugs 33 formed by the pump body 6 are provided, which, in a maximum extension position of the adapter part 20, rest on a locking shoulder 34 formed by the outer wall of the adapter part 20 (see Figure 1). List of reference symbols 1 Storage container 2 Dispensing opening 3 Pump device 4 Piston 5 Inner surface 6 Pump body 6' Pump 7 Volume 8 Reservoir 9 Propellant storage volume 10 Feed opening 11 Through opening 12 Lower external thread 13 Internal thread 14 Upper external thread 15 Piston wall 16 Storage chamber 17 Cover 18 Upper opening 19 Pump chamber 20 Adapter part 21 Base 22 Bottom 23 Locking lug 24 Sealing plate 25 Seal 26 Sealing surface 27 Lower opening 28 Insertion cavity 29 Pot opening 30 Bottom of piston 31 Longitudinal groove 32 Projection 33 Locking lug 34 Locking shoulder 35 Lower end of piston wall 36 Spring element M Mass T Propellant a Dispensing axis V0 free volume V1 free volume QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature DE 20 2005 019 298 U1

[0002]

Claims

Dispenser for portioning liquid to pasty masses (M) with a storage container (1) and a dispensing opening (2) arranged at the top of the storage container (1) for dispensing the mass (M), and with a pumping device (3) which interacts with a piston (4) arranged inside the storage container (1), which, when the pumping device (3) is actuated, can be displaced from bottom to top on an inner surface (5) of the storage container (1), characterized in that the pumping device (3) is arranged below the piston (4). Dispenser according to claim 1, characterized in that the pump device (3) is detachably attached to a lower end section of the storage container (1). Dispenser according to one of the preceding claims, characterized in that the pumping device (3) comprises a pump (6') which is configured to feed a propellant (T) into a volume (7) below the piston (4). Dispenser according to one of the preceding claims, characterized by a reservoir (8) detachably attachable to the pumping device (3), which forms a propellant storage volume (9) in which the propellant (T), in particular liquid, can be stored. Dispenser according to claim 4, characterized in that the reservoir (8) for feeding in the propellant (T) is openable and in particular is detachably attached to the pumping device (3). Dispenser according to claim 4 or 5, characterized in that the propellant storage volume (9) is larger than the volume of the storage container (1). Dispenser according to one of claims 3 to 6, characterized in that a free volume (V0,V1) enclosed by a lower section of the piston (4) available for receiving the propellant (T) is smaller in a starting position in which the piston (4) is located before a first pump actuation than in an upper displacement position of the piston (4) into which the piston (4) is displaced after a pump actuation. Dispenser according to claim 7, characterized in that a base (21) formed by a bottom (22) of the storage container (1) projects in the initial position into a cavity of the piston (4), which is bounded upwards by a bottom (30) of the piston (4), laterally by a piston wall (15) of the piston (4) and downwards by a lower edge of the piston wall (15). Dispenser according to one of the preceding claims, characterized by a lid (17) that can be detachably attached either to an upper end section or to the lower end section of the dispenser, which forms a closing part (23) with which the dispensing opening (2) can be closed.

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