Patent Publication Number: US-10315209-B2

Title: Dispenser in particular for liquid to pasty substances

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is the National Stage of PCT/EP2016/073648. filed on Oct. 4, 2016, which claims priority under 35 U.S.C. § 119 of German Application No. 10 2015 117 127.9 filed on Oct. 7, 2015 and German Application No. 10 2016 106 017.8 filed on Apr. 1, 2016, the disclosures of which are incorporated by reference. The international application under PCT article 21(2) was not published in English. 
     FIELD OF THE ART 
     The invention initially relates to a dispenser, in particular, for liquid to pasty substances, comprising a pumping chamber that has a top pumping chamber wall and a bottom pumping chamber wall in relation to a pumping movement when the dispenser is handled normally, i.e. during a vertical pumping movement; the bottom and top pumping chamber walls extend from laterally inside to laterally outside in relation to a geometrical axis running vertically through the center the pumping chamber. 
     PRIOR ART 
     Dispensers of the kind in question are known. These are used, for example, to distribute lotions and cremes. 
     From U.S. Pat. No. 3,889,628 A, dispenser is known where a top and a bottom pumping chamber wall is provided, wherein, furthermore, also the bottom pumping chamber wall can be folded inward and can form an inner higher and outer lower area in the lateral direction. The return valve is formed in an extension of the top pumping chamber wall extending into the pumping chamber. From WO 2007/104561 A2, a dispenser is known with a top pumping chamber wall which is designed with several layers. The bottom pumping chamber wall is designed as a solid injection-moulded part. 
     Furthermore, concerning the most recent background art, reference is made to US 2005/0011913 A1. In the case of a displacement of the dispenser head in the direction of the storage space, thereby, the pumping chamber is readily made smaller. 
     SUMMARY OF THE INVENTION 
     Based on the most recent background art shown, the invention deals with the task of indicating a favourable dispenser. 
     This task is initially solved by a dispenser having a top pumping chamber wall with a pipe section extending into the pumping chamber in an extension of a discharge channel against a discharge direction of the substance. The diameter of this pipe section is adapted to an inner diameter of a bottom tubular section of the bottom pumping chamber wall so that, between the bottom pumping chamber wall and the pipe section, an annulus that is open in the direction of the inlet valve or storage space or is set during the course of a pumping operation. 
     The bottom pumping chamber wall has an EVOH layer and that it is barrier-injection-moulded. 
     With an axial displacement of the dispenser head in the direction of the storage space, the pumping chamber is initially carried along with in an uninfluenced manner until a position is reached, in which a piston snap-mounted into position on the bottom pumping chamber wall limited by an end-stop assumes an end position, in which the ventilation opening is released. 
     A reduction of the pumping chamber volume can be achieved alone or in combination with other measures by folding a pumping chamber wall inward, in particular, the bottom pumping chamber wall. In particular, folding inward takes place subsequent to a drag entrainment during the course of the pumping movement of at least one of the pumping chamber walls, preferably of the top pumping chamber wall will the other, in particular, the bottom pumping chamber wall experiences a smaller axial displacement in a preferably lateral inner area than the top pumping chamber wall. 
     From this, in the case of a pumping movement to discharge the medium, a significant reduction of the pumping chamber volume can result in the lateral inner area of the pumping chamber. 
     The connection of the bottom pumping chamber wall to the top pumping chamber wall can be given, as is also preferred, in a lateral outer area of the bottom pumping chamber wall. In the case of a pumping movement, the bottom pumping chamber wall in the lateral outer area can be displaced over an axially greater path via this connection than in the lateral inner area, which results in a corresponding partial folding in of the bottom pumping chamber wall if applicable. 
     The pumping chamber, also referred to is the top and/or bottom pumping chamber wall in the following, can be designed to be rotationally symmetric to the geometrical axis of the dispenser. In this case, the lateral direction results in being a radial direction. 
     A surface of the bottom pumping chamber wall, preferably the surface directed into the inner interior space of the pumping chamber of the bottom pumping chamber wall, can be jagged by means of preformed projections and depressions. From this, a specified folding in of the bottom pumping chamber wall can result in the case of actuating the pump. 
     The pumping chamber walls can be made of a plastic material with a high degree of barrier density, also with regard to the top pumping chamber wall, being made of multiple layers for example. In addition to an EVOH layer, the pumping chamber walls can have a coating, for example, a silicon oxide or silicon dioxide coating and/or, in the case of a design with multiple layers, if applicable, only with regard to one or a plurality of layers, consisting of a material such as PET, PBT or PA. 
     A dispenser is indicated as a result of the suggested embodiment, which is designed with a dense barrier that is sealed against oxygen at least in the area of the pumping chamber and furthermore or as an alternative, has a dense barrier that is also sealed against water vapour and/or UV light for example. 
     The depressed position can, as is preferred, be the substance discharge position. Accordingly, the ventilation of the space storing the substance preferably takes place during the course of discharging the substance from the pumping chamber. For this purpose, a closure element carried along during the course of a pumping movement is provided, namely the piston, which alternately opens and closes the ventilation opening. In addition, during the course of the pumping movement, a closure element, for example a flap, can be displaced into a position closing the ventilation opening and back again directly or indirectly by means of a displaceable dispenser head, for example, being pivotally displaced. 
     In another embodiment, the closure element can be spring-loaded into a position, for example, into the ventilation-opening open position, whereby a separate spring is provided or the spring force (alone) results from the closure element material (e.g. in the case of manufacturing the closure element from a plastic material with good elastic recovery). 
     The pump chamber can have an inlet and outlet valve. These open and close depending on the pressure at hand, preferably alternating during the course of the pumping movement. 
     In the case of deformation, the bottom pumping chamber wall can also develop its own elastic restoring force. This restoring force alone can result from the wall material and also be supported by the jaggedness of the surface of the bottom pumping chamber wall. The jaggedness can initially result from a level running transversely to the housing axis by means of projections and recesses. The restoring force acts in the direction of the raised position of the dispenser head, thereby preferably being the direction of a starting position of the pumping chamber, in which this reaches a maximum volume. 
     If applicable, a spring pre-tensioning the bottom pumping chamber wall into an initial position can additionally be provided. Hereby, it can be made of a plastic material, for example, manufactured by means of a plastic-injection-moulding method. 
     Furthermore, the spring can be held separately within the dispenser. As an alternative, the spring, in particular when manufactured from a plastic material, can be moulded on a subsection of the dispenser or be designed with it as a single piece, in particular, on a dispenser section, which cannot be displaced the course of a pumping operation. 
     The inlet and/or outlet valve can be manufactured using a second plastic material and preferably be manufactured by means of a two-component injection-moulding method. For example, the valve can be moulded into parts of the dispenser head within the scope of a two-component injection-moulding method. 
     In an embodiment, the inlet and/or outlet valve can be accommodated in a form-fitting manner within an area made via a first plastic material. In this way, furthermore, the inlet valve can be moulded within the area of the bottom pumping chamber wall and the outlet valve can be moulded within the area of the top pumping chamber wall, here within the area of the openings for the substance to flow into the pumping chamber, as well as to discharge the substance from the pumping chamber respectively. 
     The bottom pumping chamber wall can have a topside and a bottom-side tubular section, wherein the bottom-side tubular section has a lateral extension in a longitudinal cross-section, which is a tenth less or more than a tenth less, all the way to a seventh less than the lateral extension of the top side tubular section. In the case of a rotationally symmetric embodiment of the pumping chamber, in this way, the diameter of a bottom-side tubular section can correspond, for example, to 3/10 all the way to 9/10 of the diameter of the top side tubular section for example. 
     The outlet valve can also be inserted and held, for example, within the area of the discharge pipe by means of friction alone. In the case of arranging a follower piston within the storage container, only one outlet valve can be provided. 
     In a preferred embodiment, the tubular sections overlap into each other via a folding section, which primarily only extends laterally. The folding section, in a starting position of the bottom pumping chamber wall, where the initial position is preferably reached in the raised position of the dispenser head, can primarily extend into the radial direction (with reference to a longitudinal cross-section of the dispenser), meaning at a level transverse to the axis described above. 
     In any case, the bottom tubular section can be cylinder-shaped. The top tubular section can also be designed in this manner. 
     The top pumping chamber wall can have a pipe section extending into the pumping chamber against the direction of the substance&#39;s discharge. This diameter of this pipe section can be adapted to an inner diameter of the bottom tubular section of the bottom pumping chamber wall. 
     In this way, between the bottom pumping chamber wall and the pipe section, an annulus can be formed that is open in the direction of the inlet valve or the storage space or be set during the course of the pumping operation. 
     By means of the pumping movement between a raised and a depressed position, a ventilation opening of the storage space can be opened or closed. Preferably, the ventilation opening is open in the depressed position, where the depressed position preferably corresponds to the substance discharge position. The ventilation opening provides for a pressure compensation, in particular, between the substance storage space and the ambient environment. 
     In this way, a closure element can be provided for the ventilation opening. This can be motion-coupled to the bottom pumping chamber wall and/or a holder area of the inlet valve. The closure element can be carried along in this manner during the course of a pumping movement, at least across part of the path. The movement of the closure element can take place along the geometrical dispenser axis. 
     The inlet valve and/or a holder area for the inlet valve can be moved during the course of a pumping movement, thereby, in particular, being between a depressed and a raised position. 
     In a preferred embodiment, the closure element can be a piston having one or a plurality of circumferential sealing lips. Thereby, the sealing lips are preferably used to seal the storage space against the ambient environment in a pump position, in particular, in the raised position. The sealing lips preferably interact with non-displaceable areas of the dispenser. 
     The piston preferably made of a rubber or TPE material forming the closure element can be mounted to a bottom pumping chamber wall, preferably to its bottom tubular section on the outside, for example being snap-mounted. An axial shifted the entire pumping chamber and thereby also at least of the central bottom tubular section of the bottom pumping chamber wall leads to carrying along the piston accordingly, preferably into the ventilation position of the storage space or into the ventilation opening/closure position. 
     In addition, the dispenser can have a pan-like holder, in which the pumping chamber is accommodated. The pan opening of the holder can, as is preferred, be orientated toward the usual actuation direction of the dispenser head. 
     The piston can lead the bottom pumping chamber wall, in particular, as a result of the piston with the bottom tubular section of the bottom pumping chamber wall snapping in the holder in an axial direction, furthermore, also in the transverse direction to this if applicable. 
     The ranges and values ranges or multiple ranges described in the above and in the following also include all intermediate values with regard to the disclosure, in particular in one-tenth steps of the respective dimensions, if applicable, also without dimensions. For example, the indication of on tenth to seven tenths also includes the disclosure of eleven hundredths to seven tenths, one tenth to sixty-nine hundredths, eleven hundredths to sixty-nine hundredths, etc. On the one hand, the disclosure can be to limit a specified upper and/or lower range limit, as an alternative however, it can be to disclose one or a plurality of singular values from a respectively indicated range. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following, the invention is described using the enclosed drawing, which however only represents exemplary embodiments. One part, which is merely described with reference to one of the exemplary embodiments and, in the case of another exemplary embodiment, is not replaced with another part due to the feature having resulted there, is therefore also described as a possibly available part in any case for this other exemplary embodiment. The figures show: 
         FIG. 1  a dispenser in a prospective illustration arranged on a storage container. 
         FIG. 2  the dispenser in a prospective individual illustration, concerning a locked non-use position of the dispenser head; 
         FIG. 3  an illustration corresponding to  FIG. 2 , concerning the unlocked use position of the dispenser head, 
         FIG. 4  the dispenser head of the first embodiment in a longitudinal cross-section, concerning a raised position of the dispenser head; 
         FIG. 5  a subsequent illustration to  FIG. 4  within the course of displacing the dispenser head in the direction of a depressed position, concerning an intermediate position; 
         FIG. 6  a longitudinal cross-section illustration shifted by 90° around a dispenser head longitudinal axis with relation to the illustrations in  FIGS. 4 and 5 , concerning the fully depressed position of the dispenser head; 
         FIG. 7 . The raised position of the dispenser head after carrying out a pumping movement in a cross-sectional illustration in accordance with  FIG. 6 ; 
         FIG. 8  a prospective longitudinal cross-section illustration of the dispenser head of the first embodiment; 
         FIG. 9 : in illustration corresponding to  FIG. 8 , however concerning a second embodiment of the dispenser head and 
         FIG. 10  in another illustration corresponding to  FIG. 8 , concerning a dispenser head in a third embodiment 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     A dispenser  1  for liquid to pasty substances in particular is shown and described. 
     In accordance with the embodiments shown in  FIGS. 1 to 9 , the dispenser  1  can be arranged on a storage container  2  with a storage space  3 . 
     In these embodiments, the latter is directly given and limited by the container wall of the storage container  2 . 
     According to the illustration in  FIG. 10 , as an alternative, a compressible bag  4  can be provided within the storage container  2 , which forms the storage space  3 . 
     The dispenser  1  has a displaceable dispenser head  5 . The displaceability is given to achieve a pumping movement along a geometrical axis x, which is vertically aligned when the dispenser  1  is handled normally and pushed through the middle of the dispenser head  5 . 
     Primarily, the dispenser head  5 , and furthermore the entire dispenser  1 , is designed to be rotationally symmetric to the axis x, with the exception of a discharge nozzle  6  primarily radially orientated to the axis x with a discharge opening.  7 . 
     In accordance with the illustrations in  FIGS. 2 and 3 , the dispenser head  5  can be rotationally moved around the axis x from a locked position in accordance with  FIG. 2 , in which no pumping movement can be carried out, into a usage position in accordance with  FIG. 3 . From this position in accordance with  FIG. 3 , a pumping movement can be carried out, thereby discharging the substance by pressing down the dispenser head  5  and then moving the same back into the initial position. 
     A discharge channel  8  is formed within the dispenser head  5  coaxially to the axis x. On one end, this leads into the discharge nozzle  6 . 
     Opposite to the mouth this leads into, the wall of the discharge channel  8 , for example, being manufactured as a single piece and using an identical material within the scope of a plastic mould injection method or joined to top pumping chamber wall  9  via a shaped insert. 
     The top pumping chamber wall  9  primarily extends in a plate-shaped manner on a horizontal level in the case of a vertical alignment of the axis x. 
     Circumferentially along the edge of the pumping chamber wall  9 , a collar  10  is formed under the top pumping chamber wall  9 . 
     In an extension of the discharge channel  8 , opposite to it, preferably with a smaller diameter, a pipe section  11  formed as a single piece with the top pumping chamber wall  9  surrounded by the collar  10  extends under the top pumping chamber wall  9 . 
     Beneath, primarily surrounding the pipe section  11 , a bottom pumping chamber wall  12  is attached to the top pumping chamber wall  9 , in particular, via a radial collar  13 . The bottom pumping chamber wall  12  primarily has a pan shape overall, with a centrally indented area. 
     Thereby, this can be a single-piece design of the top and the bottom pumping chamber wall  9 ,  12 . Preferably, with reference to this, joining by means of welding or gluing the surfaces facing each other of the radial collar  13  and the top pumping chamber wall  9 . 
     A pumping chamber  14  results limited by the pumping chamber walls  9  and  12 . 
     The bottom pumping chamber wall  12  primarily consists of a topside tubular section  15  and a bottom-side tubular section  16 . 
     The top tubular section  15  merges into the radial collar  13 . 
     Both tubular sections  15  and  16  merge into each other via a plate-like folding section  17  primarily only extending into a radial direction to axis x (in particular, in the starting position of the dispenser head  5 ). 
     The folding section  17  is, in particular, in the unloaded starting position of the dispenser head  5  in accordance with the illustration in  FIG. 4 , spaced away from the top disc-like pumping chamber wall  9 . 
     The bottom-side tubular section  16  has, in relation to the axis x, a diameter a, which corresponds to approximately a fourth to a third of the diameter b of the top tubular section  15 . 
     In particular, the bottom tubular section  16  overall is designed to have a circular cylinder shape. The pipe section  11  can dip into this section when actuating the dispenser  1 . 
     At the foot end of the bottom tubular section  16 , an inlet valve  18  is formed. For example, this can be manufactured within the scope of a two-component injection-moulding method. 
     In particular, the bottom pumping chamber wall  12 , furthermore, preferably also the top pumping chamber wall  9  are preferably manufactured using a plastic material with a high degree of barrier density. In this way, a multiple of layers can be provided in this respect. This can be achieved by means of barrier-injection-moulding using PP (polypropylene) or EVOH (ethylene/vinyl alcohol copolymer) or by designing the pumping chamber walls out of PET (polyethylene terephthalate) or PBT (polybutylene terephthalate) or PA (polyamide). Furthermore, a coating with silicon oxide or silicon dioxide can be provided, this also in the case of designing the wall with a multiple of layers, where, if applicable, only one or also a plurality of layers are coated in this manner. 
     Both the inlet valve  18  as well as an outlet valve  19  provided in the transition from the pipe section  11  into the discharge channel  8 , which is preferably also manufactured within the scope of a two-component injection-moulding process, are, in particular, made of another plastic material, particularly out of another soft plastic material against the pumping chamber walls. 
     The foot end of the bottom tubular section  16 , which faces away from the discharge channel  8 , of the bottom pumping chamber wall  12  is designed to snap-lock a closure element  20  in a fixed position arranged in a outwardly in a radial manner. The closure element  20  is motion-coupled to the bottom pumping chamber wall  12  or fixed to its bottom tubular section  16 . 
     The closure element  20  is designed as a type of piston  21  with circumferential sealing lips  22 , which are axially spaced away from each other, primarily aligned outwardly in a radial manner. Both sealing lips  22  provided extend on different radii. 
     The piston  21  is led in a pan section  23  aligned coaxially to the axis x. The axial end positions can be defined in this area, for example, as a result of setting of piston section at corresponding protrusions of the pan section  23 . 
     The pan section  23  is part of a holder  24 . Overall, this is pan-like in shape, having a pan base  25 , which, in particular, separates the storage space  3  from the dispenser head  5 . 
     Preferably, on the pan base  25 , there is an opening  27  provided, at which a suction pipe  28  can connected beneath as an axial extension to the discharge channel  8  and the pipe section  11 , furthermore as an axial extension to a central piston opening  26 . This dips into the substance. 
     With reference to a dispenser head starting position in accordance with  FIG. 4 , a ventilation opening  29  is formed between the sealing lips  22  of the piston  21  in the area of the pan base  25 . This is generally open toward the storage space  3 . 
     A spring  30  impinges the bottom pumping chamber wall  12  in the area of the radial collar  13 . The spring  30  is supported on the other end on a pan base  25  of the holder  24 ; the holder  24  in which the pumping chamber  14  is held in its entirety. The top pumping chamber wall  9  can be led by the circumferential wall of the holder  24 . The wall of the holder  24  can provide a stop limitation in interaction with the collar of the top pumping chamber wall  9  at least upwardly to the raised position of the dispenser head. 
     Via the spring impingement of the bottom pumping chamber wall  12 , the top pumping chamber wall  9  is loaded and thereby, the entire dispenser head  5  is loaded in the direction of the raised position. A pumping movement, meaning pressing down the dispenser head  5  to discharge substance, occurs against the force of the spring  30 . In accordance with the first embodiment, the spring  30  can be a metal spring, in particular a cylindrical spring. 
       FIG. 9  shows a second embodiment based on the first embodiment with a plastic spring, for example, manufactured within the scope of a plastic injection-moulding method, which spirally extends from the pan base  25  to the arrangement on the radial collar  13  of the bottom pumping chamber wall  12 , thereby surrounding the axis x. 
     An annulus  31  results, which is open in the direction of the inlet valve  18  between the bottom pumping chamber wall  12  or its bottom tubular section  16  and the pipe section  11 . 
     In order to discharge substance from the storage space  3 , the dispenser head  5  is brought from a raised position in accordance with  FIG. 4  into a depressed position in accordance with  FIG. 6 . The actuating pressure against the force of the spring  30  required for this is represented by the arrow P. 
     With an axial displacement of the dispenser head  5  in the direction of the storage container  2 , the pumping chamber  14  is initially carried along in an uninfluenced manner until reaching a position in accordance with  FIG. 5 , in which the piston  21  that is into a fixed position on the bottom pumping chamber wall  12  assumes an end position limited by an end-stop, at which the ventilation opening  29  is released. 
     As a result of the displacement of a pumping chamber wall  9  and the top tubular section  15  attached to it relative to the fixed bottom tubular section  16  thereby occurring, the other axial displacement of the dispenser head  5  results in the folding section  17  folding inward (cf.  FIG. 6 ). In this position, the radial inner area of the bottom pumping chamber wall  12  is spaced away from the top pumping chamber wall  9  less than an radial outer area. 
     The discharge of substance occurring can result in an additional effect, since a collapse of the bottom pumping chamber wall  12  can occur only upon the end of the dispenser head displacement and hereby, if applicable, substance can be subsequently discharged again. 
     The bottom pumping chamber wall  12  can build up an intrinsic elastic restoring force as a result of this folding inward, if applicable, additionally supporting the spring  30 . 
     In the embodiment shown in  FIG. 10 , where a bag  4  is arranged in the container  2 , in particular, the ventilation opening is done without. Accordingly, the closure element  20  and the piston  21  can be done without. In this embodiment, the bottom tubular section  16  of the bottom pumping chamber wall  12  is directly snap-mounted to the pan base  25 . By using the downwards displacement of the dispenser head  5  to discharge substance, a relative displacement between the top tubular section  15  and the bottom tubular section  16  of the bottom pumping chamber wall  12  directly occurs. 
     The aforementioned embodiments serve to explain the inventions recognised by the application overall, which also independently further develop the most recent background art, at least by means of the following feature combinations respectively, namely: 
     A dispenser  1 , characterized in that the bottom pumping chamber wall  12  is joined to the top pumping chamber wall  9  by designing the two walls as a single piece, or by welding or gluing the two walls together, and when the dispenser is actuated, the bottom pumping chamber wall  12  deforms by folding inward such that an elevated region is formed inside in the lateral direction and a lowered region is formed outside in the lateral direction in order for substance to be dispensed. 
     In order to further improve the dispenser of the kind in question, it is initially and primarily provided that the bottom pumping chamber wall  9  is joined to the top pumping chamber wall by designing the two walls as a single piece, or by welding or gluing the two walls together, and that the pumping chamber walls  9 ,  12  are made of a plastic material, which has a high degree of barrier density, for example, being made of multiple layers and has a EVOH layer or has a coating, for example, a silicon oxide or silicon dioxide coating and/or, in the case of a design with multiple layers, if only applicable with regard to one or a plurality of layers, consisting of a material such as PET, PBT or PA. 
     A dispenser  1 , characterized in that the pumping chamber  14  has an inlet and outlet valve  18 ,  19 . 
     A dispenser  1 , characterized in that the bottom pumping chamber wall  12  develops an intrinsic elastic restoring force when deforming. 
     A dispenser  1 , characterized in that, if applicable, additionally, a spring  30  is provided that pretensions the bottom pumping chamber wall  12  into an initial position. 
     A dispenser, characterized in that the inlet and/or outlet valve  18 ,  19  is manufactured using a second plastic material and is preferably manufactured within the scope of a two-component injection-moulding method. 
     A dispenser  1 , characterized in that the inlet and/or outlet valve  18 ,  19  in a form-fitting manner within an area formed by a first plastic material. 
     A dispenser  1 , characterized in that the bottom pumping chamber wall  12  has a topside  15  and a bottom-side tubular section  16 , wherein the bottom-side tubular section ( 16 ) has a lateral extension in a longitudinal cross-section, which is a tenth less or more than a tenth less, all the way to a seventh less than the lateral extension of the topside tubular section  15 . 
     A dispenser  1 , characterized in that the tubular sections  15 ,  17  merge into each other through a folding section  17 , which primarily extends only in a lateral manner. 
     A dispenser  1 , characterized in that the bottom tubular section  16  is in any case cylindrical. 
     A dispenser  1 , characterized in that the top pumping chamber wall  9  has a pipe section  11  extending into the pumping chamber  14  against the discharge direction. 
     A dispenser  1 , characterized in that, between the bottom pumping chamber wall  12  and the pipe section  11 , there is an annulus that is open in the direction of the inlet valve  18  or a storage space  3 . 
     A dispenser  1 , characterized in that the ventilation opening  29  is closed in the raised position and open in the depressed position. 
     A dispenser  1 , characterized in that a ventilation opening  29  of the storage space  3  can be opened and closed by the pumping movement between a depressed and a raised position. 
     A dispenser  1 , characterized in that the ventilation opening  29  is open in the depressed position. 
     A dispenser  1 , characterized in that a closure element for  20  for the ventilation opening  29  is motion-coupled with a bottom pumping chamber wall  12  and/or a holder area of the inlet valve  18 . 
     A dispenser  1 , characterized in that the closure element  20  has a piston  21  that has one or a plurality of circumferential sealing lips  22 . 
     A dispenser  1  characterized in that the piston  21  made of a rubber or TPE material is snap-mounted on the outside to the bottom pumping chamber wall  12 , preferably to its bottom tubular section  16 . 
     A dispenser  1 , characterized in that the dispenser  1  has a pan-like holder  24 , in which the pumping chamber  14  is accommodated. 
     A dispenser  1 , characterized in that the piston  21  leads the bottom pumping chamber wall  12  in the holder  24 . 
     All disclosed features (on their own, but also in combination with one another) are essential to the invention. In the disclosure of the application, the disclosure contents of the related/enclosed priority documents (copy of the pre-application) shall hereby be fully included, and also concerning this purpose, features of these documents must be included in claims of the present application. The subclaims with their features characterize further independent inventive embodiments of the most recent prior art, in particular, in order to make divisional applications based on these claims. 
     LIST OF REFERENCE NUMBERS 
     
         
           1  dispenser 
           2  storage container 
           3  storage space 
           4  bag 
           5  dispenser head 
           6  discharge nozzle 
           7  discharge opening 
           8  discharge channel 
           9  top pumping chamber wall 
           10  collar 
           11  pipe section 
           12  bottom pumping chamber wall 
           13  radial collar 
           14  pumping chamber 
           15  top tubular section 
           16  bottom tubular section 
           17  folding section 
           18  inlet valve 
           19  outlet valve 
           20  closure element 
           21  piston 
           22  sealing lip 
           23  pan section 
           24  holder 
           25  pan base 
           26  piston opening 
           27  opening 
           28  suction pipe 
           29  ventilation opening 
           30  spring 
           31  annulus 
         a diameter 
         b diameter 
         x axis 
         P arrow