EP0213073A1 - Device for mixing and applying liquid or pasty substances - Google Patents

Abstract

A piston press contains liquid and / or pasty substances in its chambers (58). According to the invention, their pistons (72 ... 75) are connected via at least one blade (80) which cuts the cartridge walls lying between the pistons (72 ... 75) when the pistons (72 ... 75) penetrate into the interior of the cartridge. For all pistons (72 ... 75) only one or - for piston presses operated with propellant gas - no piston rod is required. In this way, a very compact structure of the press can be achieved. When the pistons (71 ... 75) are actuated, the cartridges (58) are pushed forward in a first step. Here valves (114) are opened and the substances can get into the nozzle (23). A reset element (84) ensures that after actuation of the piston press, the cartridges (58) are returned to the rear position, so that the valves (114) are closed again and no more substances can leak out.

Description

The present invention relates to a device according to the preamble of claim 1 and its use, further to a method according to claim 11 and a device related thereto. Two- or multi-component systems, in which two or more substances are stored separately, each mixed when used and applied at the desired location, are becoming more and more widespread as adhesives, fillers, for foaming transport packaging for shock-sensitive transport goods, for coating surfaces, etc.

In the case of the known two-component adhesives in particular, it is important that the mixing ratio is maintained to an accuracy of approximately 10% and that the two components are mixed sufficiently thoroughly. Experience has shown that sins are very common here. This is due to the fact that the components are sold and stored in tubes. When in use, the user places the tube contents on a surface, for example on a piece of paper or in a plate-like container, and mixes the components using a stir bar. Especially when small amounts of glue are required, mixing errors occur or the mixture is mixed too little. As a result, the adhesive mixture does not harden properly and the adhesive point does not last. If the adhesive mixture contains too much hardener, it also has a highly corrosive effect. But also with correct accessories This adhesive process has disadvantages. The various work processes, especially manual fishing, take a lot of time and are a not negligible cost factor. The open adhesive mixture can be easily contaminated and is not harmless to handle, even from a work hygiene perspective. For example, skin contact with the hardener can cause dermatoses.

From FR-A-2 501 080 and US-A-4 366 919 devices with some of the features specified in the preamble of claim 1 are known. In the device according to FR-A-2 501 080, a discharge channel section is provided between the front end of the cartridge and the discharge nozzle connection, through which the components from the individual chambers are introduced into the mixing nozzle in separate channels. The chamber outlet openings of the outer chamber are formed by two diametrically opposed passages, from which two channels lead radially to the cartridge center and from there are introduced together with the component from the central chamber into the mixing chamber along a discharge channel for the component.

• Infolge der unterschiedlichen Viskosität der Komponenten und aufgrund der bei den unterschiedlich ausgebildeten Kolben in unterschiedlicher Größe auftretenden Reibkräfte legen z.B. mit Preßluft beaufschlagte Kolben bei gleichen Druck unterschiedliche Wegstrecken zurück. Damit ein genaues Mischverhältnis eingehalten werden kann, müssen die Kolben jedoch die gleiche Wegstrecke zurücklegen. Dies ist nur möglich, wenn eine mechanische Verbindung zwischen den Kolben besteht. Diese Verbindung muß so ausgestaltet sein, daß sie auch dann besteht, wenn sich die Kolben am vorderen Ende der Kartusche befinden. Aus diesem Grunde ist bei den bekannten Vorrichtungen hinter der Kartusche ein Aufbau erforderlich, der ungefähr der Patronenlänge entspricht. Dadurch wird die Vorrichtung schwer und unhandlich.

Although these known devices simplify the handling of the mixing and metering problems described at the outset to a certain extent, these devices have the following disadvantages in particular:

• As a result of the different viscosity of the components and due to the friction forces occurring in different sizes in the differently designed pistons, pressurize with compressed air piston struck back different distances at the same pressure. However, in order to maintain an exact mixing ratio, the pistons must cover the same distance. This is only possible if there is a mechanical connection between the pistons. This connection must be designed so that it exists even when the pistons are at the front end of the cartridge. For this reason, a structure is required behind the cartridge in the known devices, which corresponds approximately to the cartridge length. This makes the device heavy and unwieldy.

From DE-OS 25 21 392 a device is known in which the space required for the piston coupling is considerably reduced. In this device, the interior of the cartridge is divided into its longitudinal alignment by a cartridge wall designed as a partition. With a cutting device that runs in front of the piston, the partition is separated and passed through the piston provided with corresponding slots. A cutting edge serving as a piston coupling, which holds the piston, which is divided into almost two parts, also carries the cutting edge. The bridge is provided with appropriately designed guides so that the partitions can be guided past it.

The cumbersome piston coupling construction requires means for deflecting the cut partitions. This takes up a considerable amount of usable space inside the housing. Furthermore, deflecting the partition parts absorbs valuable squeezing pressure. This can be special This can be problematic with piston presses operated with propellant gas, since only relatively low propellant gas pressures are permitted due to official safety regulations. In addition, the deflection process causes a strong deformation of the cartridge walls, which are already heavily used by the squeezing forces, and leads to problems with the tightness of the squeezing pistons.

A similar device is known from EP-A 0119847, in which two chambers are formed in a cylindrical housing by a flexible partition wall running in the longitudinal direction of the housing and fastened to the housing wall. This is separated or separated by a plunger by means of an elaborately designed piston and stowed or deflected in an area behind the piston in the direction of advance so as not to impede further piston advance. The disadvantage here is the cumbersome piston construction, the need for housing space required for this and the increased need for operating pressure for actuating the deflection means for the separated partitions.

Another problem with the known devices is in connection with the formation of their outlet section for the components or the substances. For convenience, the exit end is often left open; especially when the dosing process only has to be interrupted for a short time. Now it is the case that the individual components show different run-out behavior when the Pistons are not operated. A low-viscosity substance with many air pockets is much more likely to leak than a highly viscous substance without air pockets. If the device is left with the outlet end open, it can happen that, for example, the hardener runs off into the mixing nozzle, whereas this is not the case with the resin. With this, however, the dosing ratio of the components is disrupted from the outset during the next dosing process, with all the disadvantages mentioned at the beginning. But then the mixture is not only highly corrosion-triggering, but the adhesive strength of an adhesive mixture, for example, can no longer be guaranteed. Such a device would be intolerable, in particular for the construction and repair of vehicles and would hardly be approved by a state inspection agency.

It is known from EP-A-0 105 181 to provide a valve to be operated separately from the component discharge in the discharge section. The handling of such valves is obviously cumbersome.

The invention, as characterized in the claims, solves the task of avoiding the disadvantages of the known to create a device of the type defined, in which the component discharge from the respective chambers of the cartridge can be metered reliably, which consists of simple and few components is constructed and correspondingly inexpensive to manufacture, works reliably and allows simple cartridge replacement.

A great advantage of the device according to the invention is that the pistons are coupled directly via blades or a downstream thin connecting flange, which manage with a minimum of space. Because the additional space-consuming coupling means are eliminated, there is great flexibility in use. It is not only possible to couple pistons arranged inside the cartridge and separated by partition walls, but even pistons located beyond the cartridge walls. The piston coupling is easy to manufacture. No power-consuming deflecting means are required and neither cartridges nor partition walls (apart from the slits, of course) are deformed. As a result, the tightness of the pistons is not in question.

In a preferred embodiment, pneumatically or hydraulically operated piston presses are provided with drive pistons which are guided outside the cartridge walls. With this arrangement, a pressure ratio can be achieved which - especially when the metering substances are viscous and the available propellant pressure is low - enables the piston press to be operated. In addition, the pistons guided outside the cartridges can be used to exert a counter pressure to the pistons guided inside the cartridges, so that a high sealing effect can be achieved even in the event of minor unevenness in the cartridge walls and despite the deformation forces acting on the cartridge walls as a result of the high pressures.

Another very great advantage of the device according to the invention is the arrangement of the valve elements in the region of the discharge channel section in connection with its actuation when the cartridges are moved longitudinally. The cartridges are preferably mounted on a cartridge carriage. This is located in the front of the housing and can be moved a limited distance in the longitudinal direction of the housing. Here, the valves are closed in the rear position of the cartridge carriage, which is to be regarded as the rest position, but are open in the front position, which is to be regarded as the working position.

The cartridge carriage is held in the rear position either with locking means or, for example, with a spring. The valves are closed. For this reason, when a drive force acts on the squeeze-out piston, the contents of the cartridge cannot be pressed out, so that the drive force initially causes the cartridge slide to be moved forward. The valves are only opened by further movement forwards and the cartridge contents can flow out. During a pressing-out process, the pressure forces exerted by the pressing-out pistons keep the cartridge slide in the front position.

As soon as the pressure on the squeezing pistons stops, reset elements ensure that the cartridge slide is brought into the rear position. The valves are closed again.

• Fig. 1 eine Darstellung einer pneumatisch arbeitenden, erfindungsgemässen Vorrichtung,
• Fig. 2 eine Darstellung eines diesbezüglichen Ventilstückes,
• Fig. 3 ein explosionsartig dargestellter Schnitt durch ein Ventilstück, eine Mischdüse und eine Ueberwurfmutter,
• Fig. 4 Ventilstellung bei vorderer Kartuschenposition
• Fig. 5 eine zur Hälfte im Schnitt dargestellte Seitenansicht auf ein diesbezügliches Kolbenaggregat,
• Fig. 6 eine Vorderansicht auf das Kolbenaggregat der Fig. 5,
• Fig. 7 eine Darstellung einer rein mechanisch arbeitenden Ausführungsvariante,
• Fig. 8 einen Längsschnitt durch eine Ausführungsvariante, einer pneumatisch arbeitenden erfindungsgemässen'Vorrichtung,
• Fig. 9a, 9b eine explosionsartige Darstellung eines Kolbenaggregates,
• Fig. 10 eine diesbezügliche Detailansicht,
• Fig. 11 eine explosionsartig dargestellte Variante eines Kolbenaggregates,
• Fig. 12 eine explosionsartige Darstellung der Befestigung des Ventiles,
• Fi.g 13 eine Darstellung des Stösselaggregates beim Eindringen in die Kartuschen,
• Fig. 14a,14b je einen Längsschnitt durch eine weitere Ausführungsvariante bei verschiedenen Positionen der Kartuschen.

The invention is explained in more detail below with reference to a drawing, for example. Show it:

• 1 is an illustration of a pneumatically operating device according to the invention,
• 2 is an illustration of a related valve piece,
• 3 shows an exploded section through a valve piece, a mixing nozzle and a union nut,
• Fig. 4 valve position in the front cartridge position
• 5 shows a side view, half shown in section, of a piston unit in this regard,
• 6 is a front view of the piston unit of FIG. 5,
• 7 is an illustration of a purely mechanical embodiment variant,
• 8 shows a longitudinal section through an embodiment variant of a pneumatically operating device according to the invention,
• 9a, 9b an exploded view of a piston assembly,
• 10 is a related detail view,
• 11 is an exploded variant of a piston assembly,
• 12 is an exploded view of the attachment of the valve,
• 13 shows a representation of the plunger assembly when it enters the cartridges,
• 14a, 14b each show a longitudinal section through a further embodiment variant with different positions of the cartridges.

The housing of the device shown in FIG. 1 consists of a support tube 1, a front cover 11, which is fixed by a union nut 10 that can be screwed onto the support tube 1, and a rear screw-on closure cap 9. A cartridge 2 is located inside the support tube 1 , which is double-walled. An inner partition 7 defines a cylindrical space in which the one component, for example a resin, is introduced. This cylindrical space is referred to below as the central chamber 3. A cylindrical annular space is formed from the intermediate wall 7 and an outer wall 35 of the cartridge 2, which is referred to below as the annular chamber 4. In this annular chamber 4, the other component, for example wise a hardener, introduced. The two chambers 3 and 4 are delimited at the front by the front wall 33 of the cartridge 2. At the rear end, the central chamber 3 is equipped with a round piston 5, and the annular chamber 4 with an annular piston 6. The pistons 5 and 6 have sealing lips 8 at their edges. Four blades 19, two of which are visible in FIG. 1, connect the two pistons 5 and 6. Decentrally on the outer edge of the front wall 33 of the, cartridge 2, the chambers 3, 4 open into a cartridge opening 13. The intermediate wall 7, which up to the cartridge opening 13 is sufficient, dividing the latter into separate output channels 2 ₄ and 2 ₅ . A valve piece 14 is pushed into the cartridge mouth 13 and is explained in more detail with reference to FIGS. 2 and 3. This is clamped by means of a union nut 50 on an outlet connection 49 formed by the front cover 11. A mixing nozzle 23 is attached to the mouth of the valve piece 14. The attachment is also carried out by means of the union nut 50. On the front cover 11 there is also a front connection piece 15 for the inlet of compressed air. The cover 5 screwed onto the rear end of the support tube 1 contains a rear connection piece 20 for compressed air.

Fig. 2 shows a perspective view of the valve piece 14. It is provided with two valve channels 28, 29, which are indicated by dashed lines, the inlet openings of which can still be seen in the figure. The valve piece 14 is provided from the rear with a slot 27 into which the part 12 of the partition 7 located in the cartridge mouth 13 can be pushed. At the rear part of the valve piece 14 are two sealing flags 3 _0th

Adjacent to the sealing lugs 30, two valve slots 43 serve to admit the components into the valve channels 28, 29. In the front area there is an annular elevation 51, on the front shoulder of which the valve piece 14 is fastened to the outlet connection 49 by means of the union nut 50 (see in this respect Fig . l). The mixing nozzle 23 is attached to the thread 32 by means of the union nut 50! (the latter is also shown in Fig. 1). The front part of the valve piece 14 is closed off by a partition wall 26 which is explained in more detail below.

3 shows an exploded view of how the mixing nozzle 23 can be fastened on the valve piece 14 by means of the union nut 50. The two valve channels 28, 29 can be clearly seen in the longitudinal section through the valve piece 14. The mixing nozzle 23 is designed at its rear end as an attachment 53, so that a liquid-tight contact is ensured between the valve piece 14 and the mixing nozzle 23. The components to be processed are kept separate when passing through the interior of the attachment 53 through the partition wall 26 of the valve piece 14. A multiplicity of mixing elements are located in a static mixing channel 52 of the mixing nozzle 23. The term "static" means that there are no moving parts.

Fig. 4 shows the relative displacement between the valve piece 14 and the cartridge 2 when it is in the front position. It can be seen that the cartridge mouth 13 opens the valve slots 43 so that the substances in the cartridge chambers 3, 4 can easily get into the valve channels 28 and 29, respectively.

5, the piston assembly 5, 6, 19 is shown from the side. The annular piston 6 is visible on the left, in the middle of the round piston 5. The two pistons 5, 6 are connected by blades 19. Both the annular piston 6 and the round piston 5 have sealing lips 8 at the front edges.

6 shows a top view of the piston assembly. In the middle, the round piston 5 is again visible, which is connected via four blades 19 to the annular piston 6 arranged coaxially around it.

The operation of the device is explained below. By actuating an actuating button or actuating lever, which is not shown in FIG. 1, a changeover part 22 of a schematically illustrated three-way valve 21 is brought into position I. As a result, compressed air is conducted into the rear connecting piece 20 and the piston assembly 5, 6, 19 is pushed forward. In a first phase, the cartridge 2 together with the piston assembly 5, 6, 19 is pushed forward until the cartridge front wall 33 comes to a stop on the front cover 11. With the displacement movement of the cartridge 2 to the front, the rear part of the valve piece 14 reaches the interior of the two chambers 3 and 4 from the cartridge opening 13. This cartridge position is shown in a partial view according to FIG. 4.

In a second phase, the piston assembly 5, 6, 19 now also moves relative to the cartridge 2 and is pushed forward in it. This movement is possible because the connecting elements between the pistons 5, 6 are designed as blades 19 and the intermediate Cut wall 7 of cartridge 2 continuously. No substance can run out at the interface, since the blades 19 are arranged behind the piston surfaces facing the substances. Since the cartridge 2 is used only once anyway, it does not matter that the partitions are cut after use. Due to the pressure of the piston assembly 5, 6, 19, the substances in the interior of the cartridge are pressed forward and pass through the valve slots 43 into the two valve channels 28 and 29 and from there into the mixing nozzle 23. There they are mixed in the mixing channel 52 and can pass through the Exit opening 45 are applied to the desired location.

As soon as the actuating member for interrupting the dosing process is released, the changeover part 22 goes to position II and compressed air is fed into the front connecting piece 15. The front wall 33 is pressurized with compressed air and brings the cartridge 2 back into the rear position. The valve slots 43 are covered again by the cartridge mouth 13. In addition, the valve channels 28, 29 are sealed by the valve lugs 30 with their sealing lips against the cartridge chambers 3, 4. So no more substances can get into the mixing nozzle 23.

With inexpensive components, a clean separation of the components is guaranteed. The cartridge 2, which is to be regarded as a disposable part, does not require a thread, which would make the manufacturing process very expensive. The partition 7 in the cartridge 2 continues up to its mouth 13, is received by the slot 27 of the valve piece 14, the partition wall 26 of which up to the static mixing channel 52 of the mixing nozzle 23 ensures separation of the components. The mixing nozzle 23, which, like the cartridge 2, is to be regarded as a disposable part, does not require an expensive thread.

The compressed air can be switched off again; the cartridge is locked in the rear position. For this purpose, locking means not shown in the figure are to be provided. For this purpose, locking notches in the cartridge wall, for example, are suitable, into which the sealing caps 30 can snap.

A reduced pressure of the compressed air is sufficient to move the cartridge 2 backwards. This is particularly important when removing the cartridge 2. Otherwise, the cartridge 2 would be conveyed out of the support tube 1 like a bullet when the rear cover 9 was removed.

Disposable pressure bottles, which can be used in a pressure range of 4 - 6 bar, are ideally suited as blowing agents. For example, highly viscous 2-component adhesive mixtures can be processed without any problems.

So that the pistons 5, 6 can be actuated as easily as possible, they must be made from a material that has the lowest possible coefficient of friction. Polybutylene terephthalate (PBTB) is ideally suited for this purpose, since it is also characterized by excellent dimensional stability and high creep resistance. Polyethylene, polypropylene or polybutylene terephthalate are the most suitable materials for the cartridge 2 or at least its intermediate wall 7. These materials are not only very inexpensive and light can be cut, but are also characterized by high chemical resistance.

7 shows a further, purely mechanical embodiment variant of the invention. In this embodiment variant, a handle 37 is built on the back of the cover 9. The front part is identical to that of the pneumatic version, except that a return spring 34 is provided as the return element. In the handle 37 there is a toothed rack 36 for actuating the pistons 5, 6. This is moved forward by means of a pawl 40 which is fastened to an actuating lever 38. To prevent the rack 36 from sliding back, a pawl 41 is provided. On the rear part of the rack 36 there is a reset handle 39 and on the front part a stamp plate 46, which serves to distribute the pressure exerted by the rack 36 to the round piston 5 and, via the knife 19, also to the piston 6.

• Durch Druck auf den Betätigungshebel 38 wird die Schubklinke 40 nach vorne bewegt. Dadurch übt sie einen Druck auf die Zahnschulter 47 aus, die Zahnstange wird nach vorne bewegt,bis die Schubklinke 40 die Zahnschulter 47 verlässt. Diese Vorschubbewegung ist so bemessen, dass im ersten Teil des Vorschubweges die _iKartusche 2 soweit nach vorne bewegt wird, bis die Ventilschlitze 43 in das Kanrerinnereöffnen(vgl. hierzu Fig. 4). Der zweite Teil des Vorschubweges dient dazu, das Kolbenaggregat 5, 6, 19 um eine gewisse Wegstrecke ins Innere der Kartuschenkammern 3, 4 eindringen zu lassen, so dass eine bestimmte Substanzmenge in die Mischdüse 23 gepresst wird. Sobald die Schubklinke 40 aushängt, drückt die Rückstellfeder 34 die Kartusche 2 wieder nach hinten, so dass die Ventilschlitze 43 von der Kartuschenmündung 13 wieder abgedichtet werden. Um ein weiteres Zurückgleiten der Schubstange 36 und damit des Kolbenaggregates 5, 6, 19 zu verhindern, greift eine Sperrklinke 41 ein. Das Uebersetzungsverhältnis der Schubklinke 40 zur Sperrklinke 41 ist so zu wählen, dass einerseits die Ventilschlitze 43 sauber geöffnet bzw. abgedichtet werden und andererseits eine genügende Substanzmenge aufgetragen werden kann.

The purely mechanical version works as follows:

• Pushing the actuating lever 38 moves the pawl 40 forward. As a result, it exerts pressure on the tooth shoulder 47 and the rack is moved forward until the pawl 40 leaves the tooth shoulder 47. This feed movement is dimensioned such that the _i cartridge 2 is moved forward in the first part of the feed path until the valve slots 43 open into the interior of the canister (cf. FIG. 4). The second part of the feed path serves to allow the piston assembly 5, 6, 19 to penetrate a certain distance into the interior of the cartridge chambers 3, 4, so that a certain amount of substance is pressed into the mixing nozzle 23. As soon as the Disengaged pawl 40, the return spring 34 presses the cartridge 2 back again, so that the valve slots 43 are sealed by the cartridge mouth 13 again. In order to prevent the push rod 36 and thus the piston assembly 5, 6, 19 from sliding back further, a pawl 41 engages. The translation ratio of the pawl 40 to the pawl 41 is to be selected such that on the one hand the valve slots 43 are opened or sealed cleanly and on the other hand a sufficient amount of substance can be applied.

When inserting a new cartridge, the rack 36 must be brought fully back into the rear position. For this purpose, the reset handle 39 is rotated by 90 °, so that the toothed rack 36 can no longer be blocked by the pawl 41, and then brought into a starting position by a pulling movement.

Finally, a few words about filling the cartridge. The use of dip tubes is recommended to ensure that the filling is as bubble-free as possible. These are introduced into the mouth 13 of the cartridge for filling. In the case of highly viscous substances in particular, it is important that the air displaced by the substances can escape as well as possible. It is therefore advisable to evacuate the inside of the cartridge before filling it.

However, convenient filling is not possible if the openings of the cartridge mouth are as small as in the practical embodiment of the known device described at the beginning. Thanks to the advantageous Ge Design of the valve according to the present invention, the openings of the cartridge mouth can be provided sufficiently large to ensure a better filling of the cartridges 2.

In addition, the round-bottom pistons and the annular pistons can be provided with sealing sleeves on the compressed air side, which prevent the penetration of air into the resin or the hardener.

• a) Beim Abfüllen der Kartusche läuft die Fliessfront in der ringförmigen Kammer asymmetrisch, so dass Lufteinschlüsse unvermeidlich sind,
• b) weil infolge der Wandstärke, die Oberfläche der Trennwand auf der Seite der Ringkammer grösser ist als auf der Seite der zentralen Kammer, ist bei gleichem Kolbendruck der Druck innerhalb der Ringkammer grösser als innerhalb der zentralen Kammer. Letztere wird deshalb in der Mitte etwas gebeult, was zu Stabilitätsproblemen und damit zu Dosierfehlern führt.
• c) eine Kartusche mit koaxialen Kammern ist verhältnismässig teuer in der Herstellung.
• d) handelsübliche Kartuschen sind in der Regel nicht verwendbar.
• e) darüber hinaus muss für jedes gewünschte Mischverhältnis eine spezielle Kartusche begaut werden.

The coaxial arrangement of the cartridge chambers described above allows an extremely compact structure; however, the following difficulties are encountered:

• a) When filling the cartridge, the flow front runs asymmetrically in the annular chamber, so that air pockets are inevitable,
• b) because due to the wall thickness, the surface of the partition on the side of the annular chamber is larger than on the side of the central chamber, the pressure inside the annular chamber is greater than within the central chamber at the same piston pressure. The latter is therefore in a bit bulged in the middle, which leads to stability problems and thus to metering errors.
• c) a cartridge with coaxial chambers is relatively expensive to manufacture.
• d) Commercial cartridges are generally not usable.
• e) in addition, a special cartridge must be gassed for each desired mixing ratio.

The disadvantages just mentioned are eliminated in a further embodiment variant shown in FIGS. 8a and 8b in the rest or working position. In this embodiment variant, the housing consists of a housing tube 54 with a front closure cover 55 fastened by means of a union nut 57 and a rear closure cover 56 fastened by means of screws 90. Two cartridges 58 are threaded with their threaded outlet tubes 59 on one axially in the housing tube 54 slidably arranged cartridge carriage 60 screwed. This is provided with an O-ring 61 on its outer edge. The cartridge mouth leads into Borehole 63, which is directed radially against the central axis of the carriage 60 after a short axial course and opens at the wall of the central bore 62 in the carriage 60.

The valve piece 64 is slidably mounted in the bore 62 and screwed to a fastening cover 65 and secured by means of a lock nut 66. The fastening cover 65 is in turn screwed onto the front closure cover 55. The valve piece 64 has a valve head 68 at its rear end. Two valve channels 69 open into the side wall of this valve head 68 and lead radially inward, in order then to run axially forward into a mixing nozzle 23 fastened to the front end of the valve piece 64. A separating web 70 protruding at the front of the valve piece 64 extends into the mixing nozzle 23 and serves for better separation of the components before they enter the static mixing channel 52

On the rear cover 56, a holder H is provided with an operating lever B for holding the press and for admitting the propellant gas. With the help of control lever B, a valve, not shown, is actuated for metering the drive gas. A pressure gauge 87 for monitoring the pressure conditions can also be provided on a fastening part 86 on the rear cover 56.

It is advantageous if the cartridges 58 - as provided in this exemplary embodiment - are already equipped with ejection pistons 71. These then serve as a rear closure for the cartridges during transport and storage. In this way it can be avoided that the usual sealing caps have to be exchanged for squeezing pistons. In the case of such manipulations, substances can flow out of the cartridge and reach unwanted places inside or outside the housing.

The pistons are in turn made up of several parts. Firstly, there are squeeze-out pistons 71 which can optionally be supplied with the cartridges. To actuate these squeezing pistons, drive pistons 72 ... 75 are provided, which are designed as drive parts 72, 74 on the parts directed against the driving air and on the parts which can be inserted into the interior of the chamber and directed against the drive piston 71 as push parts 73. The squeeze-out pistons 71 are disposable and are replaced when the cartridge is used up, while the drive pistons 72 ... 75 can be provided for repeated use. The part which remains outside the cartridges and which is upstream of the drive part 74 serves as a sealing part 75, the function of which will be explained further below. In the case of the drive pistons 72 ... 75, the piston parts 72, 73 located inside the cartridge are referred to as "inner drive pistons" and the piston parts 74, 75 remaining outside the cartridge are referred to as "outer drive pistons". A ring called a "ring knife" Shaped blade 80 not only couples the inner drive pistons 72, 73 and thus also the squeezing pistons 71 to one another, but also creates a coupling between the inner and outer drive pistons (72, 74 and 74, 75). In the exemplary embodiment, both the plunger parts 73 and the sealing part 75 are constructed separately from the corresponding drive parts 72 and 84 and are connected to these by screws 88. Thanks to this separate construction, the piston-coupling ring knife 80 can be conveniently inserted and, if necessary, easily replaced. On the other hand, it is possible to manufacture the drive pistons 72 ... 75, ie drive parts 72, 74, plunger parts 73 and sealing part 75 together with the knife as a blade / piston unit in one piece. Thermoplastic with high compressive strength could be used as a material for this.

Finally, the connecting piece 85 should also be mentioned, through which propellant gas can be admitted into the interior of the housing tube 54 for the purpose of resetting the drive pistons 72.

The drive pistons 72 ... 85 are shown in detail in FIGS. 9a, 9b. Fig. 9a shows an exploded view of the drive piston 72 ... 85 in a separate construction and Fig. 9b shows a corresponding longitudinal section. The plunger part 73 is provided with a slot 76 for receiving the ring knife 80. On its circumference it has a radially directed sealing lip 77, which is the blade slot 76 in Be seen the direction of action of the piston is somewhat upstream and whose function will be explained later. One threaded hole 81 each was used to hold a fastening screw 88 (see FIG. 10). In the outer drive pistons 74, 75 shown in FIGS. 9a, 9b, two bores 79 serve to receive the inner drive pistons 72, 73, a gap for the passage of the cartridges having to be taken into account when selecting the bore diameter. The bores of the sealing part 75 also each have a sealing lip 78. This is directed radially inwards and is arranged such that they are offset in relation to the radially directed sealing lips 77 of the plunger part 73, in such a way that the sealing lips 78 of the sealing part 75 are somewhat in front of the sealing lips 77 of the tappet part 73 seen in the direction of actuation of the pistons. Finally, the threaded holes 91 (FIG. 9a) in the sealing part 75, which are used for the connection to the drive part 74, should also be mentioned.

10 shows a detailed view of the drive piston 72 ... 75 with the cartridge wall 58 inserted. The tappet part 73 can be seen, which is screwed onto the cylindrical drive part 72 of the inner drive piston 72, 73 by means of a screw 88 and, via the ring knife 80, with the outer drive piston 74 , 75 is connected.

The radially directed sealing lip 77 prevents propellant gas from penetrating as far as the squeezing piston 71. Otherwise there would be the danger that the ejecting piston 71 lying loosely on the tappet part 73 is acted upon by the advancing propellant gas, stands out from the tappet part 73 and covers a different distance from the other ejecting piston 71. Then the compliance with the prescribed mixing ratio would no longer be guaranteed.

The considerable squeezing forces that arise when the drive pistons are actuated lead to the cartridge being inflated. In addition, unevenness and minor deviations from the geometric shape can be expected with the cartridge wall 58. For these reasons, there is a risk that the cartridge wall 58 will rise in places from the ejection piston 71 or also from the tappet part 73. The consequences would be serious in both cases. If the cartridge wall 58 lifts off from the ram part 73, there is - as just mentioned - the risk that the ejection piston 71 will lift off the ram part 73 and the mixing ratio will no longer be guaranteed. If the cartridge wall 58 lifts off the ejection piston 71, dosing substance can penetrate into the area of the drive piston (72 ... 75).

With its radially inwardly directed sealing lip 78, the sealing part 75 now exerts a counter pressure in the region between the plunger part 73 and the pressing-out piston 71 and in this way prevents the latter from being lifted off the cartridge wall 58.

11 shows an embodiment variant of a drive piston unit. The plunger part 73 has a Y-star-shaped slot 92 for receiving correspondingly arranged blades 89. The plunger part 73 provided for the upper borehole 79 in the sealing part 75 is shown separately, while the other plunger part 73 is located in the corresponding lower borehole 79. The knives 89 are secured by the drive parts 72, 74.

Fig. 12 shows an exploded view of the valve attachment. Two cartridges 58 can be screwed to the cartridge carriage 60. This has an O-ring 61 on its outer circumference in order to achieve a higher level of tightness. The front cover 55 is fastened to the housing tube 54 with the union nut 57. The front part of the valve piece 64 protruding from the cartridge slide 60 is provided with a thread 67 and is screwed onto the front cover 55 by means of the fastening cover 65 and secured by means of the locking nut 66. A return spring 84 pushes the cartridge carriage 60 into the rear position.

Fig. 13 shows a representation of the drive piston 72 ... 75 when penetrating the cartridges 58. It can be seen that the cartridges 58 are cut when leaving the piston assembly 72 ... 75.

The mode of operation of this device can be seen from FIGS. 8a, 8b:

When operating lever B, drive pistons 72 ... 75 are charged with propellant gas. The pressure exerted by the propellant gas on the drive pistons 72 ... 75 is transferred to the press-out pistons 71. The area of the drive pistons 72 ... 75 is larger than that of the squeeze-out pistons 71 by the area of the outer drive pistons 74, 75, so that a pressure ratio corresponding to the ratio of the piston areas takes place.

This is of particular importance for pneumatic systems. In various countries, only relatively low pressures for LPG containers are permitted within the framework of the legal safety regulations. In Switzerland, for example, a maximum pressure of just 6 bar is permitted. In practice, it has now been shown that such a low propellant pressure is inadequate in various cases, especially with very viscous dosing substances. Thus, the embodiment variant shown in FIGS. 8a, 8b - not least because of the high pressure forces required for the actuation of the mixing nozzle 23 - requires at least an extrusion pressure of 8 bar in order to ensure trouble-free working with the piston press. Thanks to the pressure ratio, it was possible to work with commercially available LPG bottles, for which a maximum pressure of 6 bar is prescribed.

Now a few words about how the valves work. As long as the cartridge is in the rear position (FIG. 8a), the channels 63 present in the cartridge carriage 60 are separated from the channels 69 of the valve piece 64, i.e. the valve is closed. The contents of the cartridge cannot be squeezed out and the pressure on the squeezing pistons moves the cartridges together with the cartridge slide forward. In the forward position (FIG. 8b), the channels 63 in the cartridge carriage are now connected to the channels 69 of the valve piece 64, in other words the valve is open. The inner drive pistons 72 can now penetrate into the interior of the cartridge while cutting the rear part of the cartridge 58 together with the squeezing piston 71, so that the substances are pressed out through the mixing nozzle 23. If the operating lever is released again, the return spring 84 presses the cartridge carriage 60 together with the cartridges 58 inward and the valve 60, 62 is closed again. So every time work is interrupted, the valve closes automatically

For devices that work with high pressures, the embodiment variant of a metering valve shown in FIGS. 14a and 14b offers a particularly inexpensive and easy-to-use solution. The rear part of the piston press, including the structure of the piston, is identical to the embodiment variants shown in FIGS. 8a ff. The same reference numbers were also used det, so that there is no need to repeat the description in this regard. In contrast, the front part of the piston press and the cartridges differs significantly from the one shown so far.

Instead of the cartridge carriage 60, valves 114 are integrated in the cartridges 58 and are guided there axially displaceably in the outlet tube 59 thereof. The muzzle tubes 59 are in turn also guided axially displaceably in a cartridge guide l03. This is screwed onto a housing front part 100. Here, an annular flange 106 serves to secure the screw seat. The front housing part 100 is fastened to the housing tube 54 by means of screws 101. A union nut 108 which can be screwed onto the front end of the cartridge guide 103 clamps the end flange 107 of a mixing nozzle 23 at the front end of the cartridge guide 103. A separating web 105 provided on the front of the cartridge guide 103 ensures that the components guided out of the cartridge guide 103 first come together in the static mixing channel 52 of the mixing nozzle 23. Instead of a union nut 108, which is an additional component, a recess could also be provided in the front part of the cartridge guide 103 so that the mixing nozzle 106 can be snapped in, so that it could be attached to the cartridge guide 103 in a bayonet-like manner.

The front part of the piston press is shown explosively in detail in FIG. 15. The holes 104 in the cartridge guide 103 serve to receive the two outlet tubes 59 of the cartridges 58. A return spring 84 presses the cartridge 58 backwards in the rest position. Valves 114 are arranged in the outlet pipes 59, the valve heads 110 of which are fixed in a notch 102 in the rear cartridge position. The longitudinal shaft 115 of a valve 114 is formed by three ribs arranged in a star-like manner with respect to one another.

When the cartridges 58 are pressed into the front position, the valve webs 115 rest against the shoulder 107 of the mixing nozzle 23, which also serves as a support part for the valves 114, and the valve heads 110 are pressed into the interior of the cartridge. This position, in which the valves 114 are open, is shown in Fig. 14a.

• In Ruhestellung (Fig. 14b) ist die Kartusche 58 in hinterer Position und die Ventilköpfe 110 sind in den Rastkerben 102 fixiert. Die Vorrichtung kann transportiert oder gelagert werden. Die Ventile sind geschlossen; der Kartuscheninhalt kann nicht auslaufen.

The valves work as follows:

• In the rest position (FIG. 14 b), the cartridge 58 is in the rear position and the valve heads 110 are fixed in the notches 102. The device can be transported or stored. The valves are closed; the contents of the cartridge cannot leak.

If compressed air is applied to the pistons (71 ... 75), the valves 114 are initially still locked in the outlet pipes 59, ie closed (FIG. 14b). The Kartu The contents of the cartridge cannot flow out, so that the pressure acts on the cartridges 58 as a whole and sends them forward. The valve stems 115 are supported on the shoulder 107 of the mixing nozzle 106 and cannot follow the cartridge movement. The valve heads 110 therefore get into the interior of the cartridges 58 during the cartridge movement. When the cartridges 58 have reached the front position (FIG. 14 a), the cartridge contents are cleared into the mixing nozzle 23. This corresponds to the working position; the pressure acts as a squeezing pressure.

If the compressed air is discharged again, the return spring 84 presses the cartridges 58 back again into the rest position (FIG. 14b). At the same time, the excess pressure remaining in the interior of the cartridge presses the valves 114 forward, where the valve heads 110 snap into the notches 102 again.

• a) Beim Einfüllen des Kartuscheninhalts sind Lufteinschlüsse unvermeidlich. Diese werden infolge des Kolbendrucks komprimiert,
• b) Die Kartuschenwände werden durch den Kolbendruck gedehnt,
• c) Die Rückstellfeder drückt die Kartuschen 58 nach Ablassen des Kolbendruckes wieder in die hintere Position. Hierbei erfahren die äusseren Antriebskolben 72...75 am Gehäuserohr 54 einen Reibungswiderstand und üben infolgedessen Druck auf die Substanz aus.

Such an overpressure inside the cartridge is built up as follows:

• a) Air pockets are inevitable when filling the cartridge contents. These are compressed due to the piston pressure,
• b) The cartridge walls are stretched by the piston pressure,
• c) The return spring presses the cartridges 58 back into the rear position after releasing the piston pressure. Here, the outer drive pistons 72 ... 75 experience a frictional resistance on the housing tube 54 and consequently exert pressure on the substance.

The in lit. a) to c), the pressure components cause the substance in the interior of the cartridge to exert pressure on the valve heads 110, drive them back into the orifices 59 and snap them into place.

The device according to the invention is also suitable for systems with more than two chambers. A system with a cartridge carriage into which more than two cartridges can be inserted is very flexible, analogous to the embodiment variants shown in FIGS. 8 and 14. These systems can be designed for a maximum number of screw-in or slide-in cartridges (for example, 9 of them), but depending on the application, only a part of the cartridges (for example, 3 of them) can be inserted into the cartridge carriage or the cartridge guide. It goes without saying that the unused cartridge spaces must be sealed.

The cartridges can also be arranged in the form of cartridge sets in which the cartridges are connected to one another in the vicinity of the cartridge mouths via a connecting flange (similar to that in FIG. 15). To this This prevents confusion when selecting and inserting individual cartridges from a cartridge set.

The exemplary embodiments explained so far make it clear that both the coupling principle of the pistons and the functional principle of the valves allow a large number of possible variations. In addition, almost all components can be made of inexpensive plastic material and are easy to assemble. The cartridges, or possibly their subchambers, are advantageously already equipped with valves and pistons when the contents of the cartridge are being filled. Valves and pistons prevent the contents of the cartridge from leaking and ensure safe transport.

In the following, attention should be drawn to a further embodiment variant in somewhat more detail. In this further embodiment variant, the cylindrical cartridge body is divided into subchambers by one or more longitudinal dividing walls or dividing walls, as is shown, for example, in EP-AO 119 847 mentioned at the beginning. However, in the embodiment variants shown in the cited document, the blades only serve to prepare the partition wall by slitting in a suitable manner in such a way that it is rolled up with corresponding deforming means or otherwise releases the actuation area of the piston drive or coupling means. According to the invention, the pistons can, however, directly via the Blades are coupled, so that the deformation and coupling means are eliminated and housing space is saved. It is no longer a problem to transfer the embodiment principle shown in FIGS. 9a and 9b to an embodiment variant with longitudinal partition walls.

In this case, the outer drive piston contains, instead of two bores for two cartridges, only one bore for a single cartridge, even if it is divided into subchambers. The squeezing pistons are now semicircular in accordance with the cross section of the subchambers and, according to the invention, are coupled via blades, as is shown in the previous exemplary embodiments. If the piston drive is pneumatic, a pressure ratio should be an advantage. In the present case, the outer drive piston has an annular shape, since the divided cartridge is best arranged in the center. A blade provided for coupling the pistons can in turn be inserted in a slot provided in the tappet and sealing part. For a variant with only two subchambers, the pistons provided for the subchambers and the outer drive piston can be coupled with a straight, knife-like blade.

The arrangement principle for the valves shown in FIG. 14a can also be very easily transferred to the present case. Instead of two round, separately arranged chambers, one encounters two semicircular partial chambers that are only divided by a simple partition. The Cartridge outlet orifices are advantageously also arranged round and somewhat spaced apart. Instead of a round valve channel, semicircular or otherwise suitable shaped cartridge openings can also be provided. It should be emphasized again that the piston coupling principle and the valve system can also be easily transferred to devices with cartridges divided into more than two subchambers.

On the other hand, both the piston coupling system and the valve arrangement according to the invention can be used for systems with only a single single-chamber cartridge. In such a variant, the piston coupling system is used for pressure transmission if, for example, a viscous flowing substance is to be squeezed out and only a low propellant pressure is available for safety reasons. Thanks to the automatic valve system, open valves can also be a thing of the past with single-chamber systems.

As can be seen from the previous explanations, both the piston coupling system and the valve system can be adapted to any cartridge shape.

In general, the invention offers space for a large number of variations. For example, it is not absolutely necessary for the piston to be coupled via the cutting means themselves. Should be for your piston coupling unsuitable cutting means, such as particularly fine blades or wire proving to be particularly advantageous in certain applications, the coupling can also take place by means of a coupling flange arranged behind the cutting means. However, it is a prerequisite that the thickness of the coupling flange corresponds approximately to that of the cutting means, so that it can be easily passed through the slot created by the cutting means in the cartridge wall and does not produce any strong friction or undue deformation of the wall parts adjacent to the slot.

• a) auf einen Kartuschenschlitten übertragen werden, der Teil eines Ventiles bildet, wie dies beispielsweise in Fig. 8a,8b gezeigt ist.
• b) zur Steuerung oder Betätigung von Ventilen verwendet werden, die unabhängig von den Kartuschen oder vom gegebenenfalls vorhandenen Kartuschenschlitten aufgebaut sind und deren Bewegungsrichtung sich von derjenigen der Kartuschen unterscheiden kann.

The idea of the invention also permits numerous variations with regard to valve control. The relative movement between cartridges and housing can

• a) are transferred to a cartridge carriage which forms part of a valve, as is shown, for example, in FIGS. 8a, 8b.
• b) are used to control or actuate valves which are constructed independently of the cartridges or of the cartridge carriage which may be present and whose direction of movement can differ from that of the cartridges.

The control valves due to the relative movement of the cartridges with respect to the housing ensures that they only be opened when there is sufficient squeezing pressure inside the cartridge.

The feature of the invention that the valve heads are integrated into the cartridge orifices and snap back into place after each piston actuation allows a cartridge that has been started to be removed from the device and kept until it is reused, the valves 114 serving as front and the ejection pistons as the rear closure caps . A cartridge change therefore only requires a simultaneous change of cartridge guide and mixing nozzle, both of which are to be regarded as disposable elements.

An electric spindle drive can also be used instead of propellant gas or a pawl drive. Since this is very cheap, a separate drive can also be provided for each cartridge chamber. In this case there is no need to connect the pistons by means of blades. When controlling the spindle drive, however, it must be ensured that the valves close again and can snap into the mouth of the cartridge. For this purpose, the spindle drive must either be automatically operated a few revolutions in the opposite direction at the end of a machining process or otherwise relieved - for example by lifting the spindle off the rack.

Claims (17)

1. A device for storing and applying at least one liquid or pasty substance, comprising a housing with a discharge nozzle provided on the same, at least one cartridge made at least partially of material that can be cut, at least two pistons separated by a cartridge wall and connected by means of a coupling device, - With at least one cutting means located downstream of the front surface of the pistons for separating the cartridge wall lying between the pistons, characterized in that the pistons (5, 6, 72 ... 75) are arranged in such a way that the cross section of the for the passage between the The corresponding, continuous gap in the piston provided for the piston walls (58) remains free and that either the cutting means (19, 80) itself or a connecting flange downstream of the cutting means is used as the piston coupling device, which flange is designed such that it can be guided through the slot in the cartridge wall created by the cutting means with little friction is. 2. Device according to claim 1, characterized in that the cartridge wall (2, 58) is at least partially made of polyethylene, polypropylene or PBTP. 3. Device according to one of claims 1 or 2, characterized in that the pistons (5, 6, 72 ... 75) are made of PBTP. 4. Device according to one of claims 1 or 2, characterized in that a first chamber (3) is arranged centrally, has a cylindrical shape and is equipped at its rear end with a round bulb (5), and that the other chambers (4th ) designed as annular chambers and arranged coaxially around the central chamber (3) and provided with an annular piston (6) at their rear end. 5. Device according to one of claims 1 to 4, characterized in that the cartridge with at least one longitudinal dividing wall divided into sub-chambers and each sub-chamber is provided at its rear end with a squeezing piston. 6. Device according to one of claims 1 to 5, characterized in that in the housing (54) a plurality of cartridges (58) arranged in a cartridge holder (60) are present. 7. Device according to one of claims 1 to 6 with drive piston for propellant gas, characterized in that the piston surface of the drive piston (72 ... 75) directed against the propellant gas is larger overall than the piston surface directed against the substances of the entirety of the squeezing pistons (71 ) that part (72, 73) of the drive pistons (72 ... 75) are arranged inside, part (74, 75) of the same outside of the cartridge (58), and that those are arranged inside and outside the cartridge (58) Drive pistons (72, 73 or 74, 75) are connected to one another via at least one blade (80). 8. The device according to claim 7, characterized in that the pistons (72, 73 or 74, 75) arranged inside and outside a cartridge (58) have sealing lips (77, 78) directed radially against the cartridge wall (58) for better sealing , wherein the sealing lips (77) of the pistons (72, 73) guided inside a cartridge (58) are offset in the axial direction in relation to those (78) outside a cartridge (58) and the sealing lips (78) outside a cartridge in the central region are arranged between the corresponding pistons guided within a cartridge (58) and the squeezing piston (71). 9. Device according to one of claims 6 or 7, characterized in that for the opposite to the pressing direction acting on the outside the drive piston (74, 75) with propellant gas arranged in the cartridges is provided in the lower region of the housing (54) next to the cartridges (58) with a connecting piece (85) for propellant gas. 10. Use of the device according to claims 1 to 6 and 9 in connection with claims 7 and 8 for the discharge of the components when using a low propellant pressure. 11. Device for storing and applying at least one liquid or pasty substance, with a housing and a discharge nozzle provided on the same, with at least one cartridge provided with an opening and with at least one piston for squeezing the substance out of the cartridge, characterized in that the If appropriate, a cartridge (58) mounted on a cartridge carriage (60) is mounted in a longitudinally displaceable manner in the housing (1, 54), so that at least one valve (14, 60, 64, 114) is provided for discharging the cartridge content from the cartridge (58) is coupled to the cartridge (58) or the cartridge slide (60) on the one hand and the housing (54) on the other hand in such a way that it is closed in the rear cartridge position and opened in the front cartridge position and that a reset element (15, 34, 84) to move the cartridge (2.58) into the rear position. 12. The apparatus according to claim 11, characterized in that the restoring element is a front inlet connection (15) for compressed air or a return spring (34, 85). 13. Device according to one of claims ₁₁ or 12, characterized in that the mouth (59) of the cartridge (58) is screwed to a cartridge slide (60) which is arranged on a valve piece (64) slidably in the axial direction that cartridge slide and valve piece (64) each have a channel (63, 69) for the passage of the substance, and that the channels (63, 69) are separated from one another in the rear cartridge position, but are connected to one another in the front cartridge position. 14. Device according to one of claims 11 to 13, characterized in that in the mouth (59) of the cartridge (58) a valve (14, 114) which is displaceable relative thereto in the axial direction is inserted, and in that the valve head (110) closes the closed valve (14, 114) inside the mouth (59) and projects into the interior of the cartridge when the valve (14, 114) is open. 15. The apparatus according to claim 14, characterized in that locking notches (102) for locking the valve ( ₁₄ , ₁₁ 4) in the mouth (59) of the cartridge (58) are provided. 16. The device according to one of claims 14 or 15; characterized in that the valve (l14) has a valve stem (115), of which a part of the valve stem (115) protrudes from the cartridge (58) when the valve (114) is closed, the length of the protruding part of the path of the cartridge ( 58) in the event of a change of position from the rear to the front position corresponds to the fact that a support part (107) which is connected to the housing (54) in an immovable manner is provided and which touches the valve stem (115) at its front end, so that during a movement the cartridge (58) to the front, the valve (14, l14) does not follow the cartridge movement relative to the housing (54), and the valve head (110) reaches the inside of the cartridge from the orifice tube (59), and that when the valve (14 ) in the rear position, the valve (114) can be closed by the excess pressure present in the cartridge (58). 17. The device according to at least one of claims 1 to 10 and at least one of claims 11 to 16.

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