DISCHARGER, STATIC PISTON AND METHOD OF DISCHARGING

Abstract

A discharger includes a dispensing element and a housing, the housing having a static piston connected to the dispensing element at least in a fluid conducting manner and with the static piston being arranged within the housing. The further includes a container containing a fluid, the container being moveable relative to the static piston and the housing, with the static piston including a piercing tip adapted to pierce a membrane or seal of the container when the container is moved towards the housing.

Claims

1. A discharger comprising: a dispensing element; a housing having a static piston connected to the dispensing element at least in a fluid conducting manner and with the static piston being arranged within the housing; and a container containing a fluid, the container being moveable relative to the static piston and the housing, the static piston comprising a piercing tip configured to pierce a membrane or seal of the container when the container is moved towards the housing, the static piston including at least one sealing element disposed in a region of the piercing tip, with the at least one sealing element providing a seal between the piercing tip and an inner surface of the container when the moveable container is moved relative to the housing into a position in which the membrane or seal is pierced and in which the at least one sealing element engages the inner surface to prevent the fluid from passing between the at least one sealing element and the inner surface and into a part of the housing.

2. The discharger in accordance with claim 1, wherein the at least one sealing element is arranged at an end of the piercing tip remote from an other end of the piercing tip comprising an inlet to the dispensing element.

3. The discharger in accordance with claim 2, wherein the membrane or seal is configured to be pierced by the other end of the piercing tip comprising the inlet.

4. The discharger in accordance with claim 1, wherein the at least one sealing element is a sealing lip.

5. The discharger in accordance with claim 1, wherein the at least one sealing element includes a first sealing element and a second sealing element, and the first sealing element having a diameter that is smaller than a diameter of the second sealing element.

6. The discharger in accordance with claim 5, wherein the diameter of the first sealing element is less than or equal to an internal diameter of the container and the diameter of the second sealing element is larger than the internal diameter of the container.

7. The discharger in accordance with claim 1, wherein the at least one sealing element includes a first sealing lip and a second sealing lip, the first and second sealing lips being configured to engage the inner surface to prevent the fluid from passing into the part of the housing.

8. The discharger in accordance with claim 7, wherein the first and second sealing lips are arranged one after the other in parallel to one another along a longitudinal axis of the discharger.

9. The discharger in accordance with claim 2, wherein a diameter of the piercing tip reduces from the at least one sealing element to the other end of the piercing tip comprising the inlet.

10. The discharger in accordance with claim 1, wherein the container comprises an interior compartment in which the fluid is initially stored prior to piercing the membrane or seal, and the inner surface is at a wall of the compartment.

11. The discharger in accordance with claim 10, the container further comprising an outer wall arranged in parallel to the wall of the compartment and a guide groove between the outer wall and the wall of the compartment, with the guide groove receiving at least some of the housing.

12. The discharger in accordance with claim 10, wherein the compartment comprises an end disposed opposite to the membrane or seal and configured substantially complementary to a shape of the piercing tip.

13. The discharger in accordance with claim 14, wherein the discharger comprises a child safety lock.

14. The discharger in accordance with claim 14, wherein the child safety lock is between the container and the housing.

15. The discharger in accordance with claim 1, wherein the at least one sealing element does not contact the housing in a storage state of the discharger and the at least one sealing element only contacts the inner surface in a discharging state or discharged state of the discharger.

16. The discharger in accordance claim 1, wherein an inner surface of a cylindrical wall of the housing comprises a further inwardly projecting sealing lip that is configured to engage a surface of the container different from the inner surface.

17. The discharger in accordance with claim 1, wherein the discharger is filled with a fluid selected from the group of members consisting of a topical medication, a medical fluid, a cosmetic or skin care preparation, a dental fluid, a veterinary fluid, an adhesive fluid, a disinfectant fluid, and combinations thereof.

18. A static piston for a discharger, comprising: a piercing tip having an inlet at an end thereof; a passage starting at the inlet and passing through the piercing tip and as through the static piston and up to an outlet of the discharger; and at least one sealing element formed at an end of the piercing tip remote from the inlet.

19. A method of discharging the fluid from the discharger, in accordance with claim 1, the method comprising: guiding the container in a direction along a longitudinal axis of the discharger towards the piercing tip of the static piston accommodated within the housing of the discharger, piercing the membrane or seal present at the container by the piercing tip causing the membrane or seal to be pierced; guiding the container further towards the static piston and bringing the inner surface of the container into engagement with the at least one sealing element arranged at the piercing tip of the static piston to prevent the fluid from passing between the at least one sealing element and the inner surface and thereby into a part of the housing; and discharging the fluid via an outlet of the discharger.

20. The discharger in accordance with claim 5, wherein the at least one sealing element includes a third sealing element and the first sealing element has a diameter that is smaller than a diameter of the third sealing element, and the second and third sealing elements have substantially identical diameters.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The invention will be explained in more detail hereinafter with reference to the drawings.

[0035] FIG. 1 is a perspective view of a discharger in a storage state;

[0036] FIG. 2 is a perspective view of the discharger of FIG. 1 in a discharged state;

[0037] FIG. 3 is a part sectional view of the discharger in the state of FIG. 1;

[0038] FIG. 4 is a part sectional view of the discharger in the state of FIG. 2; and

[0039] FIG. 5 is a sectional view of a further type of static piston of the discharger.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] In the following the same reference numerals will be used for parts having the same or equivalent function. Any statements made having regard to the direction of a component are made relative to the position shown in the drawing and can naturally vary in the actual position of application.

[0041] FIG. 1 shows a discharger 1 in a storage state. The discharger 1 comprises a dispensing element 2, a housing 3 and a container 4. The dispensing element 2 extends between a distal end 5 and a proximal end 6 and thereby defines a longitudinal axis A of the discharger 1, with an outlet 7 of the discharger 1 being configured at the distal end 5. The outlet 7 can either be a simple nozzle (not shown) or comprise a specifically designed nozzle (also not shown) that enables specific spraying actions from being undertaken with the discharger 1.

[0042] The housing 3 has a distal region 8 and a proximal region 9, with the distal region 8 of the housing 3 adjoining the proximal end 6 of the dispensing element 2. The housing 3 comprises a static piston 10 (see e.g. FIGS. 3 and 4) arranged within it and has wing-like projections 11 projecting away from the generally cylindrical shaped housing 3 in the distal region 8 of the housing 3.

[0043] The housing 3 further comprises a cut-out 15 in the distal region 8. Moreover, a nose 34 can be seen that cooperates with this cut-out. The cut-out 15 and nose 34 form parts of a snap-in connection as will be explained in the following.

[0044] The container 4 is arranged at the proximal region 9 of the housing 3. The container 4 comprises a compartment 12 in which a fluid F is stored and sealed off with respect to the static piston 10 by a seal 13″ that is configured as a membrane 13 (see FIG. 3).

[0045] In the present example the outer wall 14 of the container 4 comprises a slot 16 having two longitudinal sections 17, 17′ offset in parallel to one another and to the longitudinal axis A and connected to one another via a connection section 18. In the storage state of the discharger 1 shown in FIG. 1, a pin 19 projecting from the proximal region 9 of the housing 3 is present in the connection section 18.

[0046] In the present example, the pin 19 is placed in the connection section 18 of the slot 16. By placing the pin 19 in the connection section 18 that does not extend in the direction of the longitudinal axis A an accidental linear displacement of the container 4 relative to the housing 3 and thereby either an accidental removal of the container 4 from the housing 3 or an accidental movement of the container 4 towards the wing-like projections 11 can be prevented. In this way the discharger 1 comprises a child safety lock, with the child safety lock being formed between the container 4 and the housing 3.

[0047] On a desired activation of the discharger 1 the container 4 is rotated in the direction of the arrow B so that the pin 19 is then guided into the longitudinal section 17. Once the pin 19 is present in the longitudinal section 17, the container 4 can be pressed towards the wing-like projections 11 in the direction of the longitudinal axis A. A user can carry out the pressing of the container 4 towards the wing-like projections 11 by placing a thumb or a different finger at an end 21 of the housing and two further fingers at each of the wing-like projections 11 and then move these fingers and/or the thumb towards one another in a clamping like manner. The end 21 has a recess 22 formed therein for an improved placement of the finger/thumb at the end 21 of the container 4.

[0048] FIG. 2 shows the discharger of FIG. 1 in the discharged state, i.e. the state in which the user has pressed the container 4 from the proximal region 9 of the housing 3 up to the wing-like projections 11 formed at the housing 3. In the discharged state of the discharger 1, the fluid F stored in the compartment 12 has been discharged from the discharger 1 via the outlet 7 (see FIG. 4).

[0049] FIG. 3 shows a part sectional view of the discharger 1 shown in the state shown in FIG. 1. This view shows how the static piston 10 is arranged within the housing 3 of the discharger 1. The static piston 10 is connected to the dispensing element 2 in a fluid conducting manner.

[0050] For this purpose the static piston 10 has an inlet 23 that leads into a passage (not shown) that connects the inlet 23 with the outlet 7 of the dispensing element 2. The passage thereby extends through the static piston 10 and the dispensing element 2.

[0051] The discharger 1 is preferably designed such that the only way a fluid present in the container 4 can pass to the outside via the distal region 8 is via the inlet 23 and the passage, otherwise the housing 3 comprises sealing elements 25′, 26′, 27′, 29′ to seal off the housing 3 towards the outside.

[0052] The static piston 10 comprises a piercing tip 24 having the inlet 23 formed at one end 24″ of the piercing tip 24. The other end 24′ of the piercing tip 24 comprises a first sealing lip 25 as a first sealing element 25′. A second sealing lip 26 and a third sealing lip 27 are likewise formed at the static piston 10, as second and third sealing elements 26′, 27′. The first, second and third sealing lips 25, 26, 27 are arranged one after the other in parallel to one another in the direction of the longitudinal axis A of the discharger 1. In the storage state of the discharger 1 shown in FIG. 3 the first, second and third sealing lips 25, 26, 27 do not contact a cylindrical wall 28 of the housing 3.

[0053] The cylindrical wall 28 of the housing 3 comprises the sealing element 29′. In this instance the sealing element 29′ is a sealing lip 29 that circumferentially extends around an inner surface 30 of the cylindrical wall 28 in the proximal region 9 of the housing 3. In the storage state shown in FIG. 3 the sealing lip 29 is an inwardly projecting sealing lip 29. The sealing lip 29 projects, on the one hand, in the direction of the piercing tip 24 arranged around the longitudinal axis A and, on the other hand, into the interior of the housing 3 without engaging a further component. This means that the sealing lip 29 faces the longitudinal axis A of the discharger 1, preferably such that it does not contact nor connect with any further components other than the housing 3 in the storage state of the discharger 1.

[0054] It should be noted that a plane comprising the piercing tip 24, the inlet 23 and the end 24″ also comprises the sealing element 29′. This plane is arranged perpendicular to the longitudinal axis A.

[0055] FIG. 3 also shows a section through the container 4 of the discharger 1 in a plane perpendicular to the longitudinal axis A. As mentioned in connection with FIG. 1, the container 4 comprises the compartment 12 for containing the fluid F in the storage state. The compartment 12 extends from a seal formed by the membrane 13 to a piercing tip receiving end 31, also referred to as an end 31′ of the compartment 12, in the direction towards the end 21 of the container 4 comprising the recess 22.

[0056] The end 31′ of the compartment 12 that is oppositely disposed of the membrane 13 is formed by a wall 41 of the compartment 12. The wall 41 converges from the wall 32 to a common point 31″ at the end 31′ coinciding with the longitudinal axis A to form the end 31′ of the compartment 12. This means that a diameter of the compartment 12 reduces from the wall 32 to the longitudinal axis A along the wall 41.

[0057] As also shown the end 31′ of the compartment 12 is set back from the rear end 21 of the container 4 by approximately 30% of a length of the outer wall 14. In this connection it should be noted that the end 31′ can be set back from the rear end 21 by at least 20%, in particular by 25 to 45%, of the length of the outer wall 14.

[0058] A further web 42 is disposed in the region of the rear end 21 of the container. This further web 42 extends in parallel to the outer wall 14 between the end 31′ of the compartment 12 and the rear end 21 of the container 4. This further web 42 forms a base 43 of the recess 22 at the rear end 21 and hence a base 43 where a finger or thumb can beneficially be placed.

[0059] A size of the compartment 12 defines the volume of fluid F that can be stored in the container 4. This means that if a lesser volume of fluid F is to be stored within the compartment 12, then the length L of the compartment 12 can be selected shorter. Consequently, if a greater volume of fluid F is to be stored in the container 4 then a length L of the compartment 12 can be selected longer than in the present embodiment. Hence the volume of fluid F stored in the container 4 corresponds to a space of the container 4.

[0060] In this connection it should be noted that typical filling volumes of the compartment 12 of the container 4 are 0.1 to 10 ml, preferably 0.2 to 5 ml.

[0061] It should further be noted that a thickness of the wall 32 of the compartment 12 is typically selected in the range of 0.7 to 1.5 mm, preferably in the range of 0.9 to 1.1 mm and especially of around 1 mm. Likewise a thickness of the outer wall 14 of the container 4 is typically selected in the range of 0.7 to 1.5 mm, preferably in the range of 0.9 to 1.1 mm and especially of around 1 mm.

[0062] In this connection it should be noted that a thickness of the wall 28 of the housing 3 is typically selected in the range of 0.7 to 1.5 mm, preferably in the range of 0.9 to 1.1 mm and especially of around 1 mm.

[0063] It should be noted in this connection that if a compartment 12 of greater volume is selected then a length of the static piston 10 can also be increased in order to ensure that as much as possible of the fluid F initially stored in the compartment 12 is discharged from the discharger 1.

[0064] In the embodiment previously described the compartment 12 is integrally formed with the container 4, i.e. the container is a single-part container 4. In a further embodiment a separate compartment in the form of carriage (not shown) having a pre-defined volume could be used to form a two-part or multi-part container (also not shown). The sealing elements 25′, 26′, 27′ are then configured to interact with an inner surface of this multi-part container, i.e. with an inner surface of the carriage.

[0065] It should further be noted that the length L of the compartment 12 is defined as the distance between the membrane 13 and the piercing tip receiving end 31.

[0066] The shape of the piercing tip receiving end 31 is selected to be complementary to the shape of the piercing tip 24. This is because on discharging the fluid F stored in the compartment 12 of the container 4 as little residue of the fluid F as possible is desired, preferably such that all of the fluid F stored in the container 4 is discharged once the discharger is in the discharged state shown in FIG. 4.

[0067] As also shown in FIG. 3, the container 4 is a double walled container comprising an inner wall 32 and the outer wall 14 separated by a, preferably annular, guide groove 33. The inner wall 32 forms a wall of the compartment 12. The guide groove 33 can also be referred to as a ring-like gap that is formed between the inner wall 32 and the outer wall 14 of the double walled container. It should be noted in this connection that the at least one slot 16 extends from the guide groove 33 to an outer surface 14″ of the outer wall 14. Preferably the inner wall 32 and the outer wall 14 are injection molded in one piece during the manufacture of the container 4, with a connecting web 40 also being formed during the injection molding process connecting the inner wall 32 to the outer wall 14 at an end 40′ of the guide groove 33.

[0068] In this connection it should be noted that a length or depth of the guide groove 33 in the longitudinal axis A of the discharger 1 is approximately 90% of a length of the outer wall 14 of the discharger 1 of FIG. 3. It should further be noted that the length of the guide groove 33 can be selected to correspond to 50% to 95% of a length of the outer wall 14.

[0069] In the present example the membrane 13 also forms a front end 13′″ of the compartment 12 and thereby of the inner wall 32. The membrane 13 not only forms the front end of the compartment 12, but also defines the front end of the double barreled container 4, as the plane 13′ comprising the membrane 13 defines said front end. The plane 13′ thereby in addition to the membrane 13 also comprises an end 14′ of the outer wall 14 and an end 32′ of the wall 32. Thus, the double barreled container 4 extends from the membrane 13 to the end 21, i.e. the rear end 21, having the recess 22 formed therein.

[0070] It should be noted in this connection that an opening 33′ of the groove is arranged at the front end 13′″ of the container, i.e. the groove 33 is open towards the housing 3 in order to receive the cylindrical wall 28 at the front end 13′″ of the container.

[0071] In the storage state of the discharger 1 shown in FIG. 3, the front end of the compartment 12 is received within the housing 3, whereas the outer wall 14 of the double barreled container 4 surrounds the cylindrical wall 28 of the housing 3 in the proximal region 9 thereof. This means that the front end of the container 4 is configured to receive at least the proximal region 9 of the housing 3.

[0072] The section through the container 4 of FIG. 3 also shows the presence of a second pin 19′ at the other side of the housing 3. This second pin 19′ also cooperates with a second slot (not shown) similar to slot 16 present in the double walled container 4.

[0073] In the present embodiment the first pin 19 and the second pin 19′ are arranged at 180° with respect to one another at an outer surface 28′ of the housing 3. In practice dischargers are possible that utilize only one pin and slot arrangement or also more than two pin and slot arrangements. It is also conceivable that the pins are not arranged at 180° with respect to one another at the outer surface 28′ of the housing 3, but at a different angle to thereby ensure a correct alignment of the container 4 relative to the housing 3. As can further be seen from FIG. 3 the pins 19, 19′ are set back from an end 39 of the housing 3 in the proximal region 9.

[0074] On assembly of the discharger 1 the different components are connected to one another. It should be noted in this connection that the static piston 10 and the dispensing element 2 are preferably injection molded in one piece in a common mold in a preferred design of the discharger 1. Alternatively, an overmolding process could also be employed.

[0075] Alternatively the individual components of the discharger 1, e.g. the dispensing element 2, the housing 3, the container 4, the static piston 10, can also be formed separately and then assembled, for example, the static piston 10 and the dispensing element 2 can be connected to one another via a Luer lock connection (see e.g. FIG. 5 in this connection).

[0076] In this connection it should be noted that the components of the discharger can be formed from polymeric materials, such as PE (polyethylene), PP (polypropylene) and COC (cyclic olefin copolymers).

[0077] For example, the container 4 can be formed by a polymeric material such as COC. In this connection it should also be noted that like the assembly comprising the static piston 10 and the dispensing element 2, the housing 3 and the container 4 can also be formed in specifically designed molds (not shown) in an injection molding process as separate parts.

[0078] The assembly comprising the static piston 10 and the dispensing element 2 is then inserted into the housing 3 via the distal region of the housing 3. The assembly comprising the static piston 10 and the dispensing element 2 is fixed to the inner surface 30 of the housing 3, on the one hand, via snap-in connections, in this respect the snap-in connection is formed by the nose 34 that engages the cut-out 15 (see FIG. 1) present in the cut away section of the housing 3. A second snap-in connection is also present at the other side of the housing 3 that cannot be seen in the depicted section.

[0079] On the other hand, the assembly comprising the static piston 10 and the dispensing element 2 is fixed to the inner surface 30 of the housing 3 by a press fit. For this purpose three rings 35 are provided at the assembly comprising the static piston 10 and the dispensing element 2. In addition to ensuring a press fit, these three rings 35 also ensure the correct parallel orientation of the static piston 10 within the housing 3, i.e. that the static piston 10 is not inserted at a skew angle into the housing 3.

[0080] It should be noted in this connection, that the three rings 35, that provide the correct orientation of the static piston 10 relative to the housing 3 could also formed by only one or two larger rings (not shown).

[0081] On assembly of the container 4 at the housing 3, the cylindrical wall 28 of the proximal end region 9 of the housing 3 is inserted into the groove 33 of the container 4. The guidance of the container 4 relative to the housing 3 is further enhanced by aligning the pin 19 of the housing 3 with the longitudinal section 17′ of the container 4.

[0082] The container 4 is then moved first in the direction of the longitudinal axis A in the direction of the wing-like projections 11 by guiding the cylindrical wall 28 of the proximal region 9 of the housing 3 in the groove 33 in a linear manner. Once the pins 19, 19′ reach the end of the respective longitudinal section 17′, the container is then rotated in the direction of the arrow B (see FIG. 1) such that the pin 19 is received in the connection section 18 and is stored there, i.e. the child safety lock of the discharger 1 is activated. This means that following the rotation of the discharger 1, the child lock is activated by the radial displacement and the discharger 1 arrives in its storage state.

[0083] On displacing the discharger 1 into the discharging state and subsequently arriving in the position shown in the part sectional drawing of FIG. 4, the discharged state, the piercing tip 24 exerts a substantially uniform pressure on the membrane 13 causing this to initially deflect and then be uniformly pierced starting from the center of the membrane 13 radially outwardly and then permitting the fluid F stored in the compartment 12 to arrive directly at the inlet 23 present in the piercing tip 24 in the region of the start of the piercing of the membrane 13. Due to the pressure increased in the compartment 12 on pressing the container 4 towards the wing-like projections 11, the fluid F is discharged via the inlet 23, the passage and the outlet 7 from the dispensing element 2.

[0084] As the container 4 is moved in the direction of the longitudinal axis A towards the wing-like projections 11, the container 4 is linearly guided relative to the housing 3. This guidance is brought about by the interaction taking place between the cylindrical wall 28, the guide groove 33 and the inner and outer walls 32, 14 of the container 4.

[0085] Moreover, following the piercing of the membrane 13 and during the further guidance of the cylindrical wall 28, relative to the guide groove 33 and the inner and outer walls 32, 14 of the container 4 towards the wing-like projections 11, the sealing lip 29 present at the inner surface 30 of the housing 3 is brought into engagement with an outer surface 36 of the inner wall 32 of the double walled container 4. By the engagement of the sealing lip 29 at the outer surface 36 a seal is formed between the proximal region 9 of the housing and the container 4. The seal thereby forms a barrier to the fluid F escaping from the housing 3 in the proximal region 9, namely via the guide groove 33 and the slot 16.

[0086] The sealing lip 29 is thereby configured to only engage the outer surface 36 of the inner wall 32 once the piercing tip 24 comes into contact with the membrane 13. The sealing lip 29 maintains contact with the outer surface 36 of the inner wall 32 even after the piercing tip 14 has moved past the original position of the membrane 13 towards the piercing tip receiving end 31.

[0087] In order to ensure that a sealing element 29′ of the housing 3 engages the wall 32 of the container 4, a portion of the container 4, preferably a portion of the wall 32 of the container 4 is received within the housing 3.

[0088] As the container 4 is moved further in the direction of the longitudinal axis A, an inner surface 37 of the compartment 12 of the double walled container 4 is initially brought into contact with the first sealing lip 25. As the container 4 is moved further in the direction of the longitudinal axis A, the inner surface 37 comes into contact with the second sealing lip 26 and then with the third sealing lip 27. The sealing lips 25, 26, 27 thereby provide a seal between the static mixer 10 and the inner wall 32 of the compartment 12 of the container 4. This seal prevents a fluid F from arriving in the space 38 disposed between the piercing tip 24 and the first of the three rings 35 and thereby from passing into a part of the housing 3 at the distal region 8 of the housing 3.

[0089] A side effect of the pressure increase of the fluid F prior to discharging is, in particular with regard to viscous fluids, such as FRONTLINE, that the fluid F can leak between the inlet 23 and the membrane 13 such that it runs along the piercing tip 24 and towards the distal region 8 of the housing 3. By providing the sealing elements 25′, 26′, 27′ between the piercing tip 24 and the inner surface 37 of the compartment this movement of the fluid F into the distal region 8 of the housing 3 is avoided.

[0090] As can be seen from the part sectional drawing of FIG. 4, the first, second and third sealing lips 25, 26, 27 are in contact with the inner surface 37 of the compartment 12, thereby ensuring that no fluid F can pass from the compartment 12 via the piercing tip 24 and the first, second and third sealing lips 25, 26, 27.

[0091] FIG. 5 shows a section through a further kind of static piston 10 having the piercing tip 24. In this section one can see that the first sealing element 25′ has a diameter that is smaller than a diameter of the second sealing element 26′ and of the third sealing element 27′. The diameter of the second and third sealing elements 26′, 27′ is at least substantially identical.

[0092] In this connection it should be noted that an external diameter of the second and third sealing elements 26′, 27′ is larger than an internal diameter of the compartment 12. By way of example, the external diameter of the second and third sealing elements 26′, 27′ is selected to be 0.01 mm to 0.2 mm larger than the internal diameter of the compartment 12 of the container 4, preferably the external diameter of the second and third sealing elements 26′, 27′ is selected to be 0.05 to 0.15 mm larger than the internal diameter of the compartment 12 of the container 4.

[0093] It should further be noted that the external diameter of the first sealing element 25′ is smaller than or equal to the internal diameter of the compartment 12. By way of example, the external diameter of the first sealing element 25′ is selected to be 0.00 mm to 0.2 mm smaller than the internal diameter of the compartment 12 of the container 4, preferably the external diameter of the first sealing element 25′ is selected to be 0.02 to 0.10 mm smaller than the internal diameter of the compartment 12 of the container 4.

[0094] In use of the static piston 10 the first sealing element 25′ then pushes the pierced membrane 13 into the compartment 12 and a seal is initially effected between the membrane 13 and the first sealing element 25′. In this way the first sealing element clears the way for the second and third sealing elements 26′, 27′ in order to ensure an as good as possible seal between the inner surface 37 of the wall 32 of the compartment 12 and the piercing tip 24.

[0095] By forming the second and third sealing elements 26′, 27′ slightly larger than the internal diameter of the compartment 12, the second and third sealing elements 26′, 27′ are compressed on introduction into the compartment 12 in order to ensure an as good as possible seal between the inner surface 37 of the wall 32 of the compartment 12 and the piercing tip 24.

[0096] An axial distance (clearance) between the second and third sealing elements 26′, 27′ is selected to be in the range of 0.7 to 2 mm, in the present instance the axial distance amounts to 1 mm.

[0097] In the plane of the section shown in FIG. 5, a cross-section of the second and third sealing elements 26′, 27′ shows that these are formed as circumferentially extending sealing lips 26, 27 at a substantially triangular structure projecting from a central section 10′ of the static piston 10. The central section 10′ extends around the longitudinal axis A.

[0098] In contrast to this the first sealing element 25′ is formed as a circumferentially extending sealing lip 25 at the end 24′ of the piercing tip 24 remote from the end 24″ comprising the inlet 23. The end 24′ tapers from the sealing lip 25 towards the central section 10′

[0099] A Luer lock type connection 20 is formed at an end 23′ of the static piston 10 remote from the inlet 23. This Luer lock type connection 20 can be used to connect various kinds (not shown) of dispensing elements 2 to the static piston 10 in a simple manner.

[0100] In this connection it should be noted that the connection formed between the dispensing element 2 and the static piston 10 can also be formed using a different form of connection other than a Luer taper, such as the Luer lock of FIG. 5, or the integral connection of FIGS. 3 and 4 discussed in the foregoing. By way of example a bayonet type connection or a simple threaded connection etc. could also be provided as forms of connection between the dispensing element 2 and the static piston 10.

[0101] It should further be noted that the dispensing element 2 can be formed by a variety of components, for example, a spray head as shown in FIGS. 3 and 4; a syringe type dispensing element, e.g. a needle; a dropper type dispensing element, e.g. a simple pipe having an aperture formed at its distal end (not shown), the aperture optionally being surrounded by a thickened portion to e.g. prevent stitching; and the like can be used as a dispensing element 2. The dimensions, sizes and shapes of the first, second and third sealing elements 25′, 26′, 27′ discussed in connection with FIG. 5 can naturally be employed at the static piston 10 shown and discussed in connection with FIGS. 3 and 4.

[0102] It should be noted in this connection that the first, second and third sealing lips 25, 26, 27 are forms of sealing elements 25′, 26′, 27′ and different kinds of sealing elements 25′, 26′, 27′ other than the first, second and third sealing lips 25, 26, 27 could also be employed provided they provide the desired sealing function in this region of the discharger 1.

[0103] As can further be seen from FIG. 4, the fourth sealing lip 29 that is designed to engage the outer surface 36 of the inner wall 32 of the double walled container 4, to form a seal for the fluid F in this region, is compressed to such an extent that it is no longer visible. This level of compression is required, on the one hand, to ensure a seal in this region and, on the other hand, such that the cylindrical wall 28 can be reliably guided within the groove 33. The fourth sealing lip 29 is provided in order to ensure that if a fluid F were to pass the first, second and third sealing lips 25, 26, 27 that no fluid can escape from the discharger 1 between the housing 3 and the container 4.

[0104] The guide groove 33 is disposed at the double walled container 4 in order to receive at least some of the housing 3, preferably some of the cylindrical wall 28 of the housing 3. In this way one can ensure that the container 4 is reliably guided relative to the housing 3 and more specifically with respect to the piercing tip 24 in order, to safeguard that the various sealing elements 25′, 26′, 27′, 29′, e.g. the sealing lips 25, 26, 27 and 29 etc., are engaged in a uniform manner in order to prevent liquids from leaking from the container 4 into a part of the housing 3 or to the outside in a non-desired manner.

[0105] In this connection it should be noted that the sealing elements 25′, 26′, 27′, 29′ can either be integrally formed and/or fixedly connected to the respective parts of the housing 3. Alternatively, they could be formed by separate sealing elements (not shown), such as an O-ring, that are then arranged at the respective position e.g. in a specifically provided groove (also not shown).

[0106] The improved guidance is brought about by forming a width of the guide groove 33 marginally wider than a thickness of the cylindrical wall 28 of the housing 3 in such a way that the cylindrical wall 28 is moveably received in the guide groove 33 with sufficient clearance to move, but yet not so much clearance that a play is present between the housing 3 and the container 4 allowing these components to become skew with respect to one another.

[0107] In this connection it should be noted that the clearance between the guide groove 33 and the cylindrical wall of the housing 3 is preferably selected to be 0.1 mm on both sides of the cylindrical wall 28 of the housing 3.

[0108] The clearance can however be selected to be 0 mm on one side of the cylindrical wall 28 of the housing 3 and 0.1 mm on the other side of the cylindrical wall 28. Such a varying clearance at either side of the cylindrical wall can be due to the selection of the material of the cylindrical wall 28 of the housing 3 or of one of the walls 32, 14 of the container 4 that interact with the cylindrical wall 28 of the housing 3.

[0109] A length of the guide groove 33 in the shown example corresponds to a length of cylindrical wall 28 from the wing-like projections 11 to the end 39 in the proximal region 9 of the housing 3. Moreover, a length of the guide groove 33 corresponds to approximately a length of the inner wall 32 of the container 4. The outer wall 14 of the container 4 is longer than the inner wall 32.

[0110] The length L of the compartment 12 formed within the inner wall 32 is shorter than the length of the inner wall 32. A depth of the piercing tip receiving end 31 of the compartment 12 corresponds to approximately 20 to 30% of the length L of the compartment 12.

[0111] As also shown in FIG. 4 the wing-like projections 11 of the housing 3 do not contact the outer wall 14 of the container 4. This is because the wing-like projections 11 are arranged at a height of the housing 3 relative to the longitudinal axis A such that the static piston 10 can come to a stop at the end of the compartment 12 of the container 4 and hence the point of interaction between the static piston 10 and the piercing tip receiving end 31 defines a stop for the container 4 and not the wing-like projections 11.

[0112] Generally speaking the discharger 1 and the container 4 described herein are manually operable dischargers and containers that are held in the hand of a user. They are typically designed as suitable for storing and/or administering a single dose of a fluid F, such as a drug, a medication or other kind of preparation used in the care of humans or animals. This single dose can be administered in one, two or several steps, e.g. if a fluid F is to be administered to the eyes or nostrils of a patient or animal.