CA2187293C - Discharge apparatus for flowable media, particularly for discharge in a single stroke - Google Patents

Abstract

In a single proportioning device, e.g. an atomizer for a single stroke, a tamper-evident closure is provided in that an actuating sleeve (17) is connected in one piece with a casing portion (13) by means of material bridges (19) forming predetermined breaking points. The pump cylinder (27) received in the actuating sleeve (17) and which contains the medium (19), after destroying the material bridges is pressed by the application of adequate actuating forces by its piston (31) against a needle (42), which pierces it.
In another embodiment the tamper-evident closure can be produced by an increased resistance during piercing.

Description

DESCRIPTION
DISCHARGE APPARATUS FOR FLOWABLE MEDIA, PARTICULARLY FOR DISCHARGE IN A SINGLE STROKE
FIELD OF USE AND PRIOR ART
The invention relates to a discharge apparatus for flowable media having a basic body for receiving a medium reservoir and a thrust piston pump, partic-ularly for discharge in a single stroke, which has a pump piston displaceably on a piston runway between a starting position and a pump stroke end position, as well as a pump chamber connected to a discharge opening of the apparatus by means of a discharge channel and defined by a pump cylinder optionally forming the medium reservoir and the pump piston.
Such a discharge apparatus is described in European patent 311 863 (= US
patent 4 946 069) of the present applicant. The patent specification discloses and protects the pump cylinder and a resilient stop constructed in the manner of a snap locking means cooperating 1n such a way that prior to the discharge of a partial stroke a specific actuating pressure must be applied by the operator, so that after overcoming this pressure point the discharge of the liquid takes place with a certain minimum force and speed.
This construction ensures that e.g. on atomizing the medium the pressure from the first instant is sufficient for atomization purposes and that the pump is actuated up to its end, 1.e. performs the complete stroke and the entire con-tent of its medium reservoir, which simultaneously forms the pump cylinder, is discharged in one or two strokes. Such single or double dosing or proportion-ing devices are advantageous for the dispensing of medicaments, which are particularly critical with respect to proportioning, contamination, preserva-tion or other criteria.

2 of the applicant also discloses the use of medium reservoirs for a single discharge stroke, which are sealed by a plug simultaneously serving as the piston, the plug being perforated by a needle for actuation purposes. The medium reservoir is received in a sleeve, which has external projections and which cooperate with corresponding projections on the inside of a casing basic body in the manner of a snap fastening. On actuation it is firstly necessary z to overcome the static friction, before said beads slide on the faces against which they engage, so that a pressure point must be overcome.
PROBLEM AND SOLUTION
The problem of the invention is to so further develop such a discharge appar-atus in particular with a view to preventing an accidental double use or incomplete actuation, whilst avoiding the resulting contamination or propor-tinning problems.
According to the invention this problem is solved by a tamper-evident closure which can be destroyed by an actuating force.
The tamper-evident closure can in an embodiment of the invention be formed by at least one material bridge between at least one pump portion movable with the pump cylinder and a casing portion connected to the basic body. The material bridge is advantageously formed by a one-piece construction of the casing and pump portions.
Therefore a predetermined breaking point is created between the mutually mov-able parts of the discharge apparatus, whose intactness is a sure sign that the charge of filling of the medium reservoir is unopened and unused. The user can establish this e.g. optically or by a slight turning of the actuating part.
To facilitate checking window cutouts can be provided or parts of the pump can be made from transparent material. It is also possible to use a plastics material, which discolours in the case of a breaking deformation. Marks on the movable portion and the casing would also be possible. The material bridge is preferably formed between an actuating sleeve retaining and optionally partly receiving the pump cylinder serving as the medium reservoir and an inner por-tion of a base casing part provided with actuating shoulders. The actuating shoulders serve as a support for two fingers, the thumb pressing on the actu-ating sleeve. An adequate force can be applied in order to shear or tear off the material portion. As a result of the force applied simultaneously an adequate actuating force is produced for a reliable actuation of the pump.
The material bridges can e.g. be provided on the outer circumference of the actuating sleeve and between the latter and a ring surrounding said sleeve, which is in turn fixed to the facing part, i.e. to the casing, by snapping in.
This makes it possible to manufacture the actuating sleeve separately from the casing. However, the material bridges could also be shaped onto the casing and the circular fastening element could be fixed to the facing, movable part, the pump cylinder or the actuating sleeve, by engagement or in some other way.
So as to be able to insert in the discharge apparatus the said pump cylinder, which contains the medium and Which is normally made from glass so as to pre-vent diffusion and for compatibility reasons, preferably the base casing part is connected to a connector portion at least partly receiving the pump and having the discharge opening, e.g. by locking engagement.
Advantageously several material bridges are uniformly distributed over the circumference of the interconnected parts in order to prevent tilting during actuation. These material bridges can advantageously be located in an area, in which one of the parts, e.g. the actuating sleeve, has its terminal edge, Whilst the other actuating part starts above and somewhat outside the same.
It forms there a separating plane between mutually cooperating mould parts in the plastic injection moulding process, between which the material bridges are left behind in the manner of a flash, but with a controlled predetermined breaking force.
In order to permit a reliable separation of the material bridges with a pre-determined force, on one of the parts cooperating during the actuation of the pump and preferably on the basic body could be provided a cutting edge for the cutting through of the material bridge. It can e.g. be an inner edge of the connector portion connected to the base casing part. Whereas without such a cutting edge it is advantageous to mainly shear stress this predetermined breaking point, in this case, which is also advantageous when using materials with a high breaking elongation, a web-like shaping of the material bridges is also appropriate.
According to another embodiment the tamper-evident closure in the vicinity of a ram piercing the piston plug forming the pump piston can be formed by a ram design producing increased resistance prior to piercing. Thus, deliberately a controlled resistance opposes the ram before it initiates the start of the pump stroke on piercing. Unlike in the case of a needle construction, which mainly aims at piercing the piston plug with the minimum possible force, here a resistance is accepted in planned manner. However, it must be ensured that the piercing takes place without any detachment of parts from the piston plug, so that such parts cannot enter the medium and clog the discharge nozzle.
The ram can e.g. be made from plastic and namely together with an otherwise active pump part, which e.g. avoids the extra expenditure which would result from the introduction of a steel needle. Although in the case of the relat-ively large dimensions, which the ram can have due to its function, the con-struction of an inner channel therein would not be particularly problematical, it is much easier from the manufacturing standpoint if the ram has lateral con-duits for the medium, in which it e.g. has a cruciform cross-section. The con-duits, which then pass the medium through the piston plug, are then sealed from the outside by said plug. It is advantageous if the bottom of the piston plug, which is pierced, is located at the end of a depression, which surrounds the ram and therefore bounds the conduits. An upper face of the piston plug can cooperate with a corresponding part on the pump, so as to also there create a seal to the outside.
When the ram penetrates this depression the necessary counterpressure can be produced as is needed for the tamper-evident closure and by means of the pre-viously described markings or other measures it is possible to read off whether or not the pump has already been actuated.
These and further features can be gathered from the claims, description and drawings and the individual features, both singly and in the form of subcombin-ations, can be implemented in an embodiment of the invention and in other fields and can represent advantageous, independently protectable constructions for Which protection is hereby claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are described in greater detail hereinafter rela-tive to the drawings, wherein show:

Fig. 1 A longitudinal section through a discharge apparatus with a tamper-evident closure.
Fig. 2 A view in the direction of the arrow II in fig. 1.
Fig. 3 A detail from fig. 2, but shown in section.
Fig. 4 A section along line IV in fig. 2.
Fig. 5 A modified embodiment of the discharge apparatus according to fig. 1 in longitudinal section.
Fig. 6 A detail from fig. 5.
Fig. 7 A view in the direction of arrow VII in fig. 5.
Fig. 8 A longitudinal section through another embodiment of the discharge apparatus.
Fig. 9 A detail of fig. 8.
Fig. 10 A cross-section along line X in fig. 9.
Fig. 11 A partial longitudinal section through an embodiment with a shaped on tamper-evident closure ring.
DESCRIPTION OF EMBODIMENTS
The discharge apparatus 11 shown in fig. 1 has a two-part basic body 12. It contains a base casing part 13, which has an epaulette-like shape with two actuating shoulders 14 and a jacket 15 connected thereto. The base casing part is flat or flat-oval and has its greatest extension in the drawing plane, whereas it has smaller dimensions transversely thereto. The jacket 15 is longer on the right and left-hand sides in fig. 1 and has on its two sides roughly parallel to the drawing plane a cutout 16, which is open to the bottom.

On the base casing part 13 is injection moulded in one piece an actuating sleeve 17, namely on the lower, inside of a connector 18 projecting upwards from the part 13. The one-piece connection between the base casing part 13 and the actuating sleeve 17 takes place by means of material bridges 19, as shown in figs. 2 to 4. The gap 20 between the outer edge of an upper flange 21 of the actuating sleeve and an inner flange projection 22 in the interior of the connector 18 is bridged in the represented embodiment by three thin connecting webs, which have a triangular shape and whose tip is shaped on the web 22, so as to form predetermined breaking points. From the manufacturing standpoint, as a result of correspondingly small recesses, which scarcely exceed the dimen-sions of a normal flash, they can be formed on the separating face between two plastic injection moulded parts, which on the one hand form the space 23 in the interior of the jacket 15 and on the other the space in the connector 18.
Correspondingly the three uniformly, circumferentially distributed material bridges 19 are located in a glane formed by the inside and bottom of the actu-ating shoulders 14 on the one hand and the upper edge of the flange 21 on the other.
The actuating sleeve 17 has inner ribs 24, which roughly take up 3/4 of the length of the sleeve, considered from its bottom 25. On the same is supported the bottom 26 of a pump cylinder 27, which has the shape of a roughly cylin-drical, bottom closed sleeve made from glass and having an upper side flange 28. It simultaneously forms the reservoir for the medium 29 to be discharged and the pump cylinder. Its inner circumferential surface consequently forms the piston runway 30 for a piston 31, which is constructed in the form of a rubber or similar elastic material piston plug. In longitudinal section it has a H-shape and is a thick-walled tube, whose outer jacket forms the piston runways, with a central closure web 32 transversely closing the tube interior, so that at the top and bottom, connecting onto the closure web 32 depressions 33 are formed, which can be roughly conical.
The piston plug 31 is located on the hermetically sealed medium 29. Filling takes place with or without air inclusions. The pump cylinder is inserted with slight pressure in the upper part of the actuating sleeve and extends with its largest part over and beyond the actuating shoulders 14 through the connector 18 and into a connector portion 34, which can also be constructed as an _7_ adaptor. It is a finger-like portion, which has a substantially cylindrical or slightly conical shaft with an upper, spherical rounding running in the direc-tion of the pump axis 35. In the centre of said rounding is provided the dis-charge opening 36 in the form of a conventional spray nozzle. However, the discharge opening could also be provided for some other discharge form, e.g.
for a dosed delivery of a liquid or pasty medium, or could have other shapes, so as to permit better adaptation of the delivery to the shape of any body opening. Therefore it is also advantageous to manufacture the connector por-tion 34 separately from the base casing part and is fixed thereto by a snap fastening 37 with e.g. three tabs engaging in openings and provided with a barb-like head, the connector portion being centred on the connector 18. In order to prevent a removal of the connector portion 34, the snap fastening can be constructed in self-locking manner. A protective sleeve 38 protects the connector portion against contamination.
In the interior of the connector portion there is a piston rod portion 39, which has an inner discharge channel 40 and is inserted in the sleeve 41 shaped inwards on the upper end of the connector portion 34. In said piston rod portion 39 is inserted a ram 42 in the form of a downwardly inclined cut-off, hollow steel needle, e.g. by injecting or pressing into an opening provided with corresponding retaining ribs.
With the exception of the steel needle 42, the piston plug 31 made from rubbery materials and the glass pump cylinder/medium reservoir, all pump parts are plastic injection mouldings.
During manufacture in the component surrounding the base casing part 13 and the actuating sleeve 17 the pump cylinder 27 is inserted from above in the recep-tacle 43 formed in the actuating sleeve 17. Said cylinder 27 contains the medium 29 tightly sealed through the piston plug 31.
This is followed by the mounting of the connector portion, on which have been preassembled the piston rod portion and the ram 42 and it engages in the base casing part and is fixed via the snap fastening 37. Thus, after fitting the protective sleeve 38, the discharge apparatus is assembled. For use purposes, following the removal by the user of the protective sleeve 38, the discharge 21 ~729~

1_ apparatus is taken up between three fingers, two fingers resting on the shoul-ders 14 and the thumb on the bottom 25 of the actuating sleeve 17. The thumb engages in the window-like cutout 16 and consequently has an adequate actuating clearance. The discharge opening 36 is directed onto the corresponding point and by a powerful pressure on the actuating sleeve the actuating pressure is built up to such an extent that the predetermined breaking points formed by the material bridges 9 tear or shear and the actuating sleeve can be moved upwards together with the pump cylinder. As a result of the prior, powerful pressure build-up this takes place with a high speed, which ensures a speedy performance of the discharge stroke taking place. The pump cylinder is moved upwards against the ram 42, so that the latter pieces the central web 32 of the piston plug, but as a result of the elasticity of the piston plug material is immediately resealed on the outer face. Only through the inner channel of the ram constructed as a hollow needle can the medium escape upwards through the .
discharge channel 40 and the discharge opening 36 and is delivered there in sprayed or correspondingly proportioned manner. The lower edge of the piston rod portion 39 can engage on the upper face of the piston plug 31 and con-sequently produce a direct pressure connection with the piston, which runs downwards along the piston runway 30 and conveys the medium to the discharge opening. The length of the needle should be such that it does not project over the lower boundary of the piston plug 31, so that an almost complete discharge of the in certain circumstances very expensive medium is ensured.
Thus, the discharge apparatus offers a possibility of discharging sensitive and expensive materials in a planned and precisely dosed manner. Through the tamper-evident closure operating with material destruction it is possible at any time to check intactness and it is ensured that there is a complete deli-very of the medium with an adequate actuating pressure. The apparatus is simple to manufacture and fit, whilst can easily be adapted to different circum-stances, e.g. by different adaptor shapes. Following actuation the unit com-prising the pump cylinder 27 and actuating sleeve is loose and can optionally be drawn out in the downwards direction. The pump cylinder 27 with the pump plug 31 can be removed, so that the remainder, with the exception of the small needle, is made from one type of material, optionally plastic and can be correspondingly disposed of.

In the embodiment according to fig. 5 all parts and functions are identical with those of figs. 1 to 4, apart from the following exceptions.
As shown in fig. 7, the material bridges 19 are constructed as strip-shaped webs and consequently have no such marked, almost punctiform predetermined breaking point as in the case of the triangular material bridges of figs. 2 and 3. However, in order to ensure a clean and precise separation, a cutting edge 55 is provided, which in the represented embodiment is shaped onto a lower inner edge of the connector portion 34. The latter engages in the manner of a circular pocket over the connector 18 of the base casing part 13.
In the unoperated state the cutting edge 55 rests on the material bridge or projects somewhat over it. On actuation the material bridge is pressed against the cutting edge 55 and cut off, which is particularly advantageous if the mat-erial has a considerable breaking elongation. This cutting edge construction could also be provided on other pump components and used with other material bridge shapes. When reference is made hereinbefore to three circumferential material bridges, this merely represents an advantageous construction permit-ting a tilt-free actuation, Without there having to be an excessive number of material bridges, but a different number could also be chosen.
Fig. 8 shows an embodiment which, with respect to the shaping of the basic body 12, is largely the same as those described hereinbefore. However, in this case the basic body 12 with the base casing part 13 and the connector portion 34 are made from a plastics part. At the bottom, i.e. into the space 34 retain-ing clips 44, whose ends have barb-like latching projections, are connected to the connector portion 34.
In place of the lower bottom 25, the actuating sleeve 17 has an intermediate bottom 46, which bounds the receptacle 43 for the pump cylinder 27 and an outer guide flange 47, which engages on the substantially axially directed inside of the retaining clips 44, which run in the extension of the inner faces of the connector portion 34.
The spray nozzle forming the discharge opening is formed between the latter and the piston rod insert 48, Which is located in a sleeve 41 extended up to the pump cylinder and which is shaped in the interior of the connector portion 34. The piston rod insert 48 is pressed in there and has a lateral discharge channel 40 in the form of a groove and on its upper end face corresponding spiral groove constructions, Which belong to the vortex die. On to the under-side of the piston rod insert is shaped the ram 42 which, like the latter, is made from plastic. It is downwardly tapered or provided with a cutting edge and has a cruciform cross-section as can be seen in fig. 10. Between the cross ribs are formed channels 49.
As can in particular be gathered from fig. 9, the external dimensions of the ram are so large that it must be pressed into the depression 33 on the piston plug 31.
All the remaining parts are the same as in the previous embodiments and are given the same reference numerals in figs. 5 to 7 as in figs. 1 to 4.
In this embodiment assembly can take place by plugging together two preassembled units, namely on the one hand the basic body 12 in Which has been pressed the piston rod insert 48, and on the other the unit comprising the actuating sleeve 17 and the filled and sealed pump cylinder 27 inserted therein. Insertion can take place from the bottom in the axial direction until the guide flange 47 engages behind the latching projections 45.
During actuation pressure is exerted on the lower end of the actuating sleeve 17. As in WO 92/00812, the forces resulting from the static friction between the engaging parts 44, 47 must be overcome and the ram 42, accompanied by the deformation of the piston plug must be forced into the latter until the closure web 32 is pierced. This requires a relatively high actuating force, which is deliberately chosen higher than would normally be necessary for piercing the web 32. Under the pressure of the ram, the piston plug cannot be pressed fur-ther into the pump cylinder, because the medium is normally incompressible.
Only after the piercing of the closure web can it pass out upwards through the channels 49. The latter have in the meantime been sealed to the outside by the inner wall of the depressions 33 and by the engaging of the lower face 50 of the sleeve 41 on the upper edge 51 of the closure plug 31, so that the medium is passed through the discharge channel 40 to the discharge opening 36.

Fig. 11 shows in longitudinal section a detail of an embodiment, in which the casing 13 and connector portion 34, as in fig. 8, are constructed in one piece.
Otherwise the construction is similar to figs. 1 and 5. The same reference numerals are used for the same parts and reference is made to the previous description of said parts and their function. , On the actuating sleeve 17, which receives the container 27, is provided on the outside a fastening element 60 in the form of an all-round ring with a L-shaped cross-section. It is connected to the actuating sleeve 17 by several material bridges 19, which are so constructed and dimensioned, that they tear away under the actuating pressure and consequently separate the ring from the actuating sleeve. The fastening element 60, actuating sleeve 17 and material bridges 19 are injection moulded from plastic in one piece.
The fastening element 60 is fixed to the casing 13 by a snap connection 61.
The fastening element is centred with its axial leg on the inside of the conn-ector portion 35, whereas the outwardly directed leg latches in a depression at the transition between the actuating shoulder 14 and the connector portion 34.
During assembly the actuating sleeve is introduced together with the container 27 forming the pump cylinder. An assembly tool can press the lower engagement face 63 of the actuating element 60 in fig. 11, so that engagement of the latching connection 61 takes place without any risk of damage to the tamper-evident closure formed by the material bridges 19. However, if the user moves the sleeve upwards, the material bridges 19 tear and the actuating sleeve, together with the pump cylinder/container 27, can perform the pump stroke in the previously described manner. The actuating sleeve 17 is guided on the one hand in the circular fastening element 60 (between the torn off material bridges) and on the other on the inner webs 62 of the connector portion 34.
An outer flange of the container/pump cylinder 27 is also guided in this way, which prevents tilting of the actuating means. The material bridges 19 can also be constructed as split or through film connections.
The fastening element 60 has a certain amount of axial and radial clearance in the latching connection 61. This makes it possible to intentionally or uninten-tionally turn the actuating sleeve 17 without destroying the tamper-evident w 2187293 closure. However, the latching connection must be sufficiently strong that on drawing off the actuating sleeve 17 in the downwards direction the tamper-evident closure tears. This ensures that there have been no undesired manipul-ation of the content of the proportioning device.
Thus, a tamper-evident closure has been provided, which requires a higher, material-destroying actuating force in order to unseal the medium reservoir 27, than would be needed in the case of a simple needle. This is aided by the frictional force between the guide flange 47 and the retaining clips 44 which, after overcoming the static friction, pass into the sliding state and therefore release a larger proportion of the expended actuating force for actuation and overcoming the other resistances.

Claims (20)

1. A discharge apparatus for flowable media, comprising:
a basic body, at least partly receiving a pump unit;
said pump unit having a pump chamber connectable to a discharge opening via a discharge channel;
a pump cylinder and a pump piston bounding said pump chamber;
said pump cylinder forming a medium reservoir;
said pump piston being displaceably guided in said pump cylinder for discharging all said medium contained in said medium reservoir by a pump stroke in a pump stroke direction; and, at least one breakable material bridge between said pump unit and said basic body for destruction during said pump stroke by an actuating force exerted in said pump stroke direction, whereby said medium is discharged from said apparatus with a predetermined discharging pressure by a predetermined actuating force level and whereby said apparatus is thereby additionally provided with a destroyable tamper-evident closure.

2. A discharge apparatus according to claim 1, wherein the tamper evident closure is defined by said at least one material bridge between at least one pump portion movable in the pump cylinder and a casing portion connected to the basic body.

3. A discharge apparatus according to claim 2, wherein said at least one material bridge is defined by a one-piece construction of the casing portion and said at least one pump portion.

4. A discharge apparatus according to any one of claims 2 to 3, wherein said at least one material bridge is defined on one of: the casing portion; and the at least one pump portion, and extends from a circular fastening element engaging one of: the at least one pump portion; and the casing portion respectively.

5. A discharge apparatus according to claim 4, comprising a guide engaging the pump portion formed by one of the fastening element and an inner web of a connector portion.

6. A discharge apparatus according to any one of claims 4 to 5, wherein the fastening element has an engagement face for engaging latching means on the casing portion.

7. A discharge apparatus according to any one of claims 2 to 3, wherein said at least one material bridge is defined on an interior of the casing portion having an actuating shoulder.

8. A discharge apparatus according to claim 7, wherein the casing portion is connected to a connector portion at least partially receiving the pump unit and having a discharge opening.

9. A discharge apparatus according to any one of claims 2 to 8, wherein said at least one material bridge extends from an actuating sleeve engaging the pump cylinder.

10. A discharge apparatus according to any one of claims 2 to 9, comprising a plurality of said at least one material bridges circumferentially spaced apart within a plane.

11. A discharge apparatus according to any one of claims 2 to 10, wherein each material bridge comprises a tip connected to a wall.

12. A discharge apparatus according to any one of claims 9 to 11, wherein each material bridge is located adjacent an upper edge of the actuating sleeve and a downwardly directed edge in the interior of the casing portion.

13. A discharge apparatus according to any one of claims 1 to 12, comprising a cutting edge for cutting through each material bridge during pump actuation.

14. A discharge apparatus according to any one of claims 1 to 13, wherein the tamper-evident closure comprises a ram piercing a piston plug of the pump piston during pump actuation.

15. A discharge apparatus according to claim 14, wherein the ram has lateral channels for conducting the medium.

16. A discharge apparatus according to any one of claims 14 to 15, wherein the ram sealingly engages a depression in the piston plug.

17. A discharge apparatus according to any one of claims 14 to 16, wherein the ram has a double sided wedge shaped tip.

18. A discharge apparatus according to any one of claims 14 to 16, wherein the ram has a diameter greater than 1/6 of a pump cylinder diameter.

19. A discharge apparatus according to any one of claims 1 to 18, wherein the pump cylinder has a first marking cooperating with a second marking on the basic body, that are mutually displaced during pump actuation.

20. A discharge apparatus according to any one of claims 1 to 19, wherein an idle path is defined between a tamper evident closure position and a discharge start position defined by the start of medium discharge.