DE29622929U1 - Dispenser - Google Patents

Description

GRÜNECKER, KINKELDEY·

AN wTVfTS'fe O Zi% T

LAW FIRM MAXIMIL1ANSTRASSE 58 D-80S3S MUNICH GERMANY LAWYERS

DR, HERMANN SCHWANHÄUSSER
DR. HELMUT EICHMANN
GERHARD BARTH
DR. ULRICH BLUMENRÖDER, LL.M.
CHRISTA NIKLAS-FALTER

YOUR REF

OUR REF.

PATENT ATTORNEYS

EUROPEAN PATENT ATTORNEYS

AUGUST GRÜNEECKER

DR. HERMANN KINKELDEY

DR. WILFRIED STOCKMAIR, AE. E.

DR, KLAUS SCHUMANN

PETER H. JAKOB

DR. GUNTER BEZOLD

WOLFHARD MEISTER

HANS HlLGERS

DR. HENNING MEYER-PLATH

ANNELIE EHNOLD

THOMAS SCHUSTER

DR. WALTER LANG HOFF

DR. KLARA GOLDBACH

MARTIN AUFENANGER

GOTTFRIED KLITSCH

DR. HEIKE VOGELSANG-WENKE

REINHARD KNAUER

DIETMAR KUHL

DR. FRANZ-JOSEF ZIMMER

BETTINA K. REICHELT

DR. ANTON PFAU

DATE

G 3696-01348/sb

10,06.97

Applicant: Industrial Planning

Theodor Fessel GmbH Promenade 14 91522 Ansbach

Dispenser

TEL 089 / 21 23 50 ■ FAX (GR 3) 089 / 22 02 87 ■ FAX (GR 4) 89 / 21 86 92 93 · E MAIL postmaster@grunecker.de · TELEX 529 380 MONA D MAX(MILIANSTRASSe 58 D-80533 MUNICH DEUTSCHE BANK MUNICH, NO. 17 51734, BLZ 700 700 10

Dispenser

The present invention relates to a liquid dispenser with a valve block that can be placed on a vessel and has a suction valve/a delivery cylinder connected to the suction valve, in which a delivery piston that can be connected to an actuating device is slidably received, and a dispensing device for the liquid that can be connected to the valve block. The invention also relates to a dosing cylinder for a liquid dispenser and to a method for producing a dosing device that comprises a delivery cylinder and a valve block.

DE 43 34 750 C2 discloses a liquid dispenser for dosing liquids from a storage container, which is provided with an adjustment device by means of which the delivery quantity to be delivered can be adjusted continuously and precisely. The stroke length of a delivery piston slidably accommodated in a delivery cylinder is adjusted using this adjustment device. The delivery cylinder is made of a glass material that is resistant to the medium to be delivered. The delivery cylinder is provided with a measuring scale and a plastic coating applied using a fluidized bed process in the area of its outer surface. This fluidized bed process coating reliably ensures that no glass splinters can be released in the event of any damage to the delivery cylinder. The formation of this fluidized bed process coating on the delivery cylinder requires a relatively high level of equipment. Since the layer formed by the fluidized bed process is subject to fluctuations in terms of its thickness, the delivery cylinder is reworked in the area of its end fitting surfaces. The manufacture and assembly of the conveyor cylinder are relatively time-consuming and require special care.

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In view of this problem, the invention is based on the object of creating a liquid dispenser which enables an equally precise dosing of viscous media and can be manufactured at lower production costs.

This object is achieved according to the invention by a liquid dispenser according to patent claim 1.

This advantageously makes it possible to significantly reduce the assembly effort in the manufacture of such a liquid dispenser and to reliably ensure that the feed cylinder is firmly coupled to the valve block in a sealing and mechanically perfect manner.

A particularly advantageous embodiment of the liquid dispenser is that the delivery cylinder is a glass cylinder. This advantageously makes it possible to deliver sensitive or aggressive media in a reliable manner. Due to the particularly high surface quality of the inner wall of the glass cylinder, a reliable seal between the delivery piston and the glass cylinder is also ensured. In addition, such a glass cylinder enables the delivery piston to move particularly smoothly.

An embodiment of the invention that is particularly advantageous from a manufacturing point of view is provided by the fact that the valve block is made of plastic, in particular polypropylene. A valve block made of such a material is characterized by a particularly high chemical resistance and enables a particularly stable attachment of the liquid dispenser to the vessel.

I · · · I

An advantageous embodiment of the liquid dispenser according to a particular aspect of the present invention is provided by the fact that the glass cylinder is surrounded by a protective tube made of plastic, in particular polypropylene, which is integral with the valve block. This protects the delivery cylinder from mechanical damage in a particularly advantageous manner and also effectively prevents any splinters from spreading in the event that the delivery cylinder does break. Since the splinters of the glass cylinder surrounded by the protective tube remain in the interior formed by the protective tube, the splinters are prevented from spreading even when such a damaged fluid dispenser is disposed of. The protective tube is advantageously designed in such a way that it is firmly connected to the outer wall of the delivery cylinder. This largely prevents any glass splinters from detaching from the protective tube in the event of damage to the glass cylinder.

According to a further particular aspect of the present invention, the glass cylinder is injected into the valve block and the protective tube. This results in a particularly reliable fastening of the glass cylinder in the protective tube and on the valve block. In addition, a reliable seal is achieved between the glass cylinder and the valve block in a particularly favorable manner from a manufacturing point of view, which prevents any fluids to be conveyed from penetrating into a gap area formed between the valve block and the glass cylinder.

An advantageous embodiment of the liquid dispenser, particularly in the case of the integral design of the protective tube and valve block, is provided by the fact that the valve block is designed as a skeleton structure with spaced webs that are separated by recesses.

With this embodiment of the valve block, the liquid dispenser according to the invention can be manufactured in a particularly material-saving manner. In particular, when the valve block is manufactured as part of a plastic injection molding process, the curing period of the valve block is also significantly shortened. In a further particularly advantageous manner, the individual functional sections of the valve block can be formed in a favorable manner with such a skeleton construction. In addition, a particularly favorable structure of a corresponding molding tool is obtained. In an advantageous manner, it is also possible to determine the individual mold parting planes relatively arbitrarily. Since such an embodiment also allows any undercut sections to be avoided even with relatively thin walls, the valve block can be manufactured in a material-saving manner.

According to a particular aspect of the invention, a dosing cylinder is created with an inner wall that is largely resistant to a conveying medium, in particular made of a glass material, for a liquid dispenser to form a conveying chamber for receiving a conveying piston in a sliding manner, which is characterized in that a dosing cylinder outer wall is formed by a plastic body formed as part of a plastic molding process, and that a conveying cylinder forming the inner wall is accommodated in the plastic body. This advantageously makes it possible to use a comparatively inexpensive, thin-walled glass cylinder instead of the relatively thick-walled glass cylinders that have been used up to now and that are plastic-coated by a vortex sintering process, and to use the plastic body formed around the conveying cylinder to transmit mechanical forces. In addition, a fastening section can be formed on the conveying cylinder in a particularly favorable manufacturing manner, via which the conveying cylinder encased by the molded body can be reliably connected to a valve block.

This means that the plastic body can be manufactured in a particularly cost-effective manner.

According to a preferred embodiment of the invention, the feed cylinder made of a glass material or a suitable ceramic material is completely surrounded by the plastic material of the plastic body in the area of its outer peripheral surface. By overmolding the feed cylinder with a plastic material that forms the plastic body, a particularly stable embodiment of the dosing cylinder is obtained. To improve the (melt) connection between the plastic body and the feed cylinder, it is advantageously possible to chemically treat the outer surface of the feed cylinder. It is also possible to slightly roughen the outer surface of the feed cylinder, for example by sandblasting. Instead of a feed cylinder made of a glass material or a ceramic material, it is also possible to form the feed cylinder from another, for example thermosetting plastic material. Even when using such a conveyor cylinder, it proves to be advantageous to create an adhesive bridge by appropriately treating the outer surface of the conveyor cylinder, which enables a particularly strong adhesion of the conveyor cylinder to the plastic body.

According to a particular aspect of the present invention, the wall thickness of the plastic body is at least 1/10 of the wall thickness of the conveyor cylinder. Reliable splinter protection can be ensured even with a relatively thin wall thickness of the plastic body. According to a preferred embodiment of the invention, the wall thickness of the plastic body is greater in the area of the ends of the conveyor cylinder than in the middle area. The plastic body surrounding the conveyor cylinder has a relatively thin wall thickness over most of its length and is only thickened in the area of its front ends.

With its thickened end sections, the plastic body forms, for example, a transition area that connects to a valve body.

According to a preferred embodiment of the invention, the plastic body is made of a transparent material. This makes it easy to determine the filling level of the conveyor cylinder. The plastic body is advantageously made of polypropylene.

According to a preferred embodiment, the plastic body has a substantially cylindrical shape. For this purpose, the plastic body is advantageously formed in a molding tool which has a molding space formed by at least two mold halves, wherein the at least two mold halves can be brought into an open position by relative movement along a mold opening axis running substantially transversely to the longitudinal axis of the mold cylinder. A plastic body formed in this way can be removed from the molding space in a particularly advantageous manner without the conveyor cylinder accommodated in the plastic body being subjected to particular mechanical stresses.

Alternatively, however, it is also possible to form the plastic body using a molding tool which has a molded part that delimits a molding space and can be moved relative to the plastic body in the direction of the plastic body's longitudinal axis in order to demold the plastic body. The plastic body is advantageously slightly conical and tapered. With such an embodiment of the plastic body, a particularly high surface quality of the plastic body can be achieved in an advantageous manner.

According to a preferred embodiment of the invention, a foot base is provided in the plastic body, whereby this foot base is formed in one piece with the plastic body. The plastic body can be reliably connected to a valve block via this foot base. An embodiment of the invention which is particularly advantageous, particularly in connection with the foot base, is provided in that the dosing cylinder has a head section and that the head section is formed in one piece with the plastic body. This head section can advantageously create a stop via which the stroke length of a delivery piston can be limited.

According to a preferred embodiment of the invention, the casing wall surrounding the conveyor cylinder extends continuously between the head section and the foot base. As a result, the head section and the foot base are advantageously coupled to one another in such a way that the distance between the foot base and the head section cannot be changed. This advantageously prevents the head section from being pulled off the conveyor cylinder.

The dosing cylinder is advantageously provided with a scale and the scale is encased in the plastic body. This advantageously makes it possible to form the scale on the feed cylinder using a relatively inexpensive printing process and to prevent this scale from being abrasion-proofed by the plastic body. Alternatively, however, it is also possible to form the scale, for example, in a raised manner on the outer surface of the plastic body. With such a design of the scale, it is not necessary for the feed cylinder to be provided with a scale. As a result, the feed cylinder can simply be separated from a relatively long pipe (semi-finished product). In the event that the feed cylinder is also surrounded by the plastic body in the area of its front ends, it is not necessary to

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It is important to pay particular attention to the surface quality of the ends of the conveyor cylinder. Even if the conveyor cylinder has relatively sharp edges, injuries from these sharp edges are ruled out.

According to a preferred embodiment of the invention, an end flange formed in one piece with the plastic body is provided in an end region of the feed cylinder, the end flange extending radially inwards to the longitudinal axis of the metering cylinder. This end flange delimits the lower end of the feed chamber formed in the feed cylinder in a manner that is favorable for production. The end flange advantageously forms a small through-opening that has a smaller diameter than the inner diameter of the feed cylinder. The fluid sucked in from the vessel can be discharged to an outlet line through this small through-opening during the subsequent inward movement of the feed piston.

According to a particular aspect of the present invention, the plastic body forms an extension section that extends beyond the feed cylinder in the axial direction of the feed cylinder. This advantageously makes it possible to shorten the axial length of the feed cylinder almost to the stroke length of the feed piston. The guide surface for guiding a piston rod, which otherwise does not come into contact with the feed piston or the feed medium, is then no longer formed by the feed cylinder itself, but by the inner wall of the plastic body. In an advantageous manner, the plastic body in the area of the extension section therefore has the same inner diameter as the feed cylinder. This results in a particularly simple insertion of the feed piston into the feed cylinder and a guide of the feed piston that is insensitive to tilting.

An embodiment of the invention that is particularly advantageous for reducing the assembly effort when creating the liquid dispenser is that a valve block intended to accommodate a valve device is formed in one piece with the plastic body. This eliminates the need for subsequent assembly of the plastic body and the valve block. In addition, any leaks in the area of such a joint can be advantageously avoided. The valve block and the plastic body are advantageously formed as an integral structural unit by a plastic injection molding process. For this purpose, a preferably thermoplastic plastic is injected into a molding tool that forms a molding space through which the valve block and the plastic body are formed in one piece. The feed cylinder, which is made of a glass material in particular, is advantageously inserted into this molding space before the injection mold is closed. By injecting the plastic material, a structural unit is then formed in which the feed cylinder is firmly embedded.

The valve block is advantageously formed by a mold space formed by a mold tool consisting of at least two parts, with a separating surface of the mold tool running essentially parallel to the longitudinal axis of the conveyor cylinder. This makes it possible to design the individual wall sections of the valve block with relatively thin walls, which results in a considerable saving of material and a shortening of the curing period.

A lower area of the valve block is advantageously formed by a mold core that is drawn out of the valve block in the axial direction of the feed cylinder. Such a mold core can advantageously also form a connection pin onto which a hose element can be plugged, which extends from the valve block

to the bottom of the vessel. This connection pin advantageously comprises a channel running coaxially to the longitudinal axis of the feed cylinder. A core pin provided for forming this channel is advantageously rigidly connected to the mold core provided for forming the lower region of the valve block.

According to a further aspect of the present invention, a system is created for producing a liquid dispenser comprising a feed cylinder and a valve block, in which the valve block is formed from a plastic material inside a molding chamber during a plastic injection molding process and is removed from the molding chamber after the plastic material has hardened. This method is characterized according to the invention in that during the plastic injection molding process forming the valve block, a plastic body intended to accommodate a feed cylinder is formed in one piece with the valve block.

This advantageously makes it possible to create a cylinder/valve block unit through which the overall assembly effort in the manufacture of a liquid dispenser can be significantly reduced.

According to a preferred embodiment of the system, during the formation of the plastic body, a glass cylinder that forms the conveyor cylinder and is inserted into a mold is overmolded with a plastic material that forms the plastic body. The glass cylinder is advantageously centered by a mold core. To avoid excessive thermal stress on the glass cylinder when it comes into contact with the hot plastic injected into the mold cavity, the glass cylinder is advantageously preheated before it comes into contact with the plastic material. According to a preferred embodiment of the method, the glass cylinder is placed on the mold core in a tight fit. As a result,

It is advantageously avoided that the plastic material intended for forming the plastic body penetrates into a gap area formed between the glass cylinder and the mold core.

The glass cylinder is advantageously overmolded with the plastic material in a front end area. This covers any edges that may be formed in the end area of the glass cylinder in a cost-effective manner, so that there is no risk of injury from them. It is also possible to form a slightly conical widening in this end area, which makes it easier to insert a delivery piston into the glass cylinder.

A particularly advantageous embodiment of the system is provided by the fact that the plastic material is injected into the molding chamber at different points. This makes it possible to achieve a particularly favorable flow direction of the plastic material in the area of the feed cylinder. It is also possible to introduce the majority of the plastic material into the molding chamber in such a way that it does not come into contact with the feed cylinder.

Advantageously, different plastic materials can also be injected into the mold cavity at different points. According to a preferred embodiment of the system, a transparent or translucent plastic material, preferably polypropylene, is injected into the area of the mold cavity intended to accommodate the feed cylinder and a colored plastic material is injected into the mold cavity intended to form the valve block. The respective time course of the injection process of the respective plastic material is advantageously determined by a schedule, so that, for example,

This ensures that the feed cylinder is only covered by transparent plastic material.

An advantageous embodiment of the method for avoiding any stress on the conveyor cylinder is that the mold space is brought into an open position by opening it in a direction transverse to the longitudinal direction of the conveyor cylinder. With such an embodiment of the system, particularly short closing paths result. In addition, a corresponding mold tool can be checked and cleaned in a favorable manner. In an advantageous manner, an outer area of the cylinder valve block unit is delimited by two mold halves that delimit an outer area of the unit and by two core elements. The two core elements are advantageously inserted into the mold space delimited by the mold halves. In an advantageous manner, the conveyor cylinder is placed on the corresponding core element before the mold space is closed, thereby forming a cylinder/valve block unit in which the glass cylinder is embedded in the corresponding plastic material.

The invention is explained in more detail below using preferred embodiments and associated drawings. These show:

Fig.l shows a liquid dispenser according to the invention in longitudinal section,

Fig.2 a simplified sectional view through a mold for forming the integral unit consisting of the valve block and the feed cylinder,

Fig.3 a longitudinal sectional view through an integral unit consisting of a valve block and a feed cylinder.

Fig.4 a representation of an alternative embodiment of a liquid dispenser in longitudinal section,

Fig.5 is an individual part view of a preferred embodiment of a dispensing device provided in the liquid dispenser according to Fig.4,

Fig.6 is a functional diagram describing the switching functions of the output device according to Fig.5.

The liquid dispenser shown in Fig. 1 comprises a valve block that can be placed on a vessel and has a valve device 2 formed inside it. An interior space formed in a delivery cylinder 3 is connected to the vessel (not shown here) via this valve device 2. A delivery piston 4 is accommodated in the delivery cylinder 3 and can be moved back and forth in a sliding manner via a handle 5. A fluid sucked out of the vessel and delivered by the delivery cylinder 3 and the delivery piston 4 is delivered to a delivery cannula via a delivery device. The valve block 1 and the delivery cylinder 3 form an integral structural unit.

In the embodiment shown here, the valve block 1 is made of a plastic material, in particular polypropylene. The feed cylinder 3 is surrounded by a protective tube 8 that is integrally formed with the valve block 1. In the embodiment shown here, the feed cylinder 3 is designed as a glass cylinder and is injected into the valve block 1 and the protective tube 8 as part of a plastic injection molding process. The protective tube 8 is made of a transparent plastic material so that the degree of filling of the feed chamber formed in the feed cylinder 3 can be controlled.

· 14 · · ·

The delivery cylinder 3 is firmly accommodated in the protective tube 8 and the valve block 1. The delivery cylinder 3 is advantageously adhesively connected to the protective tube.

The valve block 1 is formed in a skeleton construction and has a number of webs 9 which delimit recesses exposed to the outside of the valve block 1.

The webs (9) shown here are each arranged in such a way that the outer area of the valve block in a two-part mold does not form any undercuts.

The valve device accommodated in the valve block 1 comprises an intake closing valve, which has an intake valve ball 10 and a spacer sleeve 11 that limits the stroke movement of this valve ball 10. A valve seat 12 of the valve device 2 is created by a peripheral edge formed on the valve block 1. This peripheral edge is formed in the mouth area of an intake channel 13, which advantageously runs coaxially to the longitudinal axis of the feed cylinder 3. The intake channel 13 runs inside a hose pin 14, which is also advantageously formed in one piece with the valve block 1.

The dispensing cannula 7 is provided with a threaded base 15 in its foot area and is screwed radially from the outside into the valve block 1. The dispensing device 6 comprises a ball valve with a dispensing valve ball 16 loaded by a spring 17. In the closed position, the dispensing valve ball 16 sits on a bushing 18 made of a plastic material. The bushing 18, the dispensing valve ball 16 and the spring 17 are accommodated coaxially to the longitudinal axis of the dispensing cannula 7 in the inner area of the threaded base 15. A through-channel formed inside the bushing 18 is in fluid communication with the conveying chamber formed in the conveying cylinder 3.

Before mounting the liquid dispenser on a vessel, a hose is attached to the hose pin 14, which extends down to the bottom of the vessel. A fluid stored in the vessel is sucked in via this hose via the valve device 2 when the delivery piston 4 moves upwards. When the delivery piston 4 moves downwards, the valve device 2 closes. As a result of a pressure build-up inside the delivery cylinder 3, the dispensing valve ball 16 is pushed from its closed position against the spring force of the spring 17 into an open position and allows the fluid to flow out.

Fluids from the conveying chamber formed in the conveying cylinder 3 via the cannula 7.

To enable pressure equalization between the interior of the vessel and the environment when a fluid is sucked in by the delivery piston 4, the valve block 1 is provided with a ventilation hole 20, which is advantageously covered by a filter plug made, for example, from sintered granulate. This filter plug can be inserted into an insertion hole that is also formed on the valve block 1 and is advantageously conically tapered. The valve block 1 is attached to the vessel in a sealing manner by means of a union nut 21. Instead of a union nut 21 formed separately from the valve block, it is also possible to form a corresponding threaded section in one piece with the valve block 1.

In the upper area of the protective tube 8, a head section 22 is formed in one piece with the latter, which forms a stop surface for a conveying stroke adjustment device 23. The head section 22 extends to the uppermost axial end of the conveying cylinder 3 and possibly also projects beyond its front end area in such a way that the peripheral edges of this end area are still covered by the plastic material of the protective tube 8.

The handle 5 provided in the liquid dispenser shown here is designed as a hollow body and, when the delivery piston 4 is in the lowered position, essentially completely covers the delivery cylinder 3 or the protective tube 8 surrounding it. A scale rod 24 of the delivery stroke adjustment device 23 is advantageously designed as one piece with the handle 5.

The integral structural unit described above in connection with Fig. 1 and formed by the valve block 1 and the feed cylinder 3 is formed according to a particular aspect of the present invention by a molding tool, the mold parts of which are provided for forming the outer region of the valve block 1 and are moved into an open or closed position in a direction running essentially transversely to the longitudinal direction of the feed cylinder 3. In the embodiment of a molding tool according to the invention shown in Fig. 2, this comprises a first mold part 25 and a second mold part 26. Both mold parts 25 and 26 can be moved in a direction transversely to the longitudinal direction of the structural unit formed by these mold parts. A first core element 28 and a second core element 29 are arranged in a mold space delimited between the two mold parts 25, 26. The first core element 28, together with the first mold part 25 and the second mold part 26, defines a mold space section in which the plastic body intended to accommodate the feed cylinder is formed. The feed cylinder 3 shown in Fig.1 can be plugged onto this first core element 28 before the first and second mold parts 25, 26 are closed. After the second core element 29 has been inserted, the first and second mold parts 25, 26 are moved together and a plastic material, preferably polypropylene, is injected into the mold space 27 that has now been formed. This plastic material fills the entire mold space 27 and thus forms an integral part of the liquid dispenser, which contains both the valve block 1 (Fig.1) and the part intended to accommodate the feed cylinder 3.

By exchanging the first and second core elements 28 and 29, in particular the first core element 28, different structural units can be produced in a simple manner, in particular with regard to the stroke volume. In particular, different internal diameters of the feed cylinders 3 can be taken into account by means of a corresponding first core element 28.

The two first and second core elements 28 and 29 are centered by the first and second mold parts 25,26. Advantageously, the two core elements are additionally inserted into one another, in particular in an area provided for forming the intake channel 13 shown in Fig.1. As an alternative to the embodiment of the mold shown here in Fig.2, it is also possible to couple at least the second core element 29 to a drive device in order to enable automatic demolding of the molded part formed in the mold space 27. The demolding movement of the first core element 28 can also be automated in an advantageous manner. A particularly reliable fitting of the first core element 28 with the feed cylinder 3 is achieved by arranging the mold in the injection mold in such a way that the valve block is arranged above the head section. The longitudinal axis of the first core element 28 is advantageously essentially vertical, with a section of the first core element 28 intended to form the valve device 2 (Fig. 1) pointing upwards. This advantageously ensures that the feed cylinder 3 cannot slide off the first core element 28 due to its own weight. The injection of the plastic material into the mold space 27 is also advantageously carried out in such a way that the feed cylinder 3 is not displaced on the first core element 28. To reduce the thermal load on the feed cylinder 3 when injecting the plastic material, the first core element 28 is advantageously preheated. The preheating of the first core element 28 can advantageously

is

This can be done by a heating device, in particular an electric one, arranged inside this core element 28.

Fig.3 shows an integral component for a liquid dispenser according to the invention, produced for example by a molding tool according to Fig.2. This integral component comprises the valve block 1 intended to accommodate the valve device 2 and a plastic body formed in one piece with it, forming the protective tube 8. The delivery cylinder 3 intended to accommodate the delivery piston 4 shown in Fig.1 is embedded in this plastic body. The embedding of the delivery cylinder 3 in the plastic body takes place as part of a plastic injection molding process, in which the valve body 1 is formed together with the plastic body in a corresponding mold space. The head section 22 is formed on an end of the plastic body forming the protective tube facing away from the valve body 1, which forms a stop surface which, in conjunction with a stroke limiting device, limits the stroke of the delivery piston 4. The valve block 1, which is formed in one piece with the plastic body intended to accommodate the feed cylinder 3, is designed as a skeleton construction with outwardly projecting webs 9. These webs 9 enable sufficient reinforcement of the valve body 1 in a material-saving manner. The hose pin 14, already described in connection with Fig. 1, is also formed in one piece with the valve block 1 on the integral part shown in Fig. 3. The area surrounding the hose pin 14 can advantageously be formed by the second core element 2 9 shown in Fig. 2. The integral part shown in Fig. 3 is preferably fastened to a vessel by means of a union nut (Fig. 1). This union nut or another suitable fastening device advantageously engages in a circumferential groove 3 0 provided in the lower area of the valve block 1. This circumferential groove is delimited by an annular flange 31, which is radially elastically flexible due to an annular groove 32 also formed in the valve block 1.

In the embodiment of the integral part shown in Fig. 3, the feed cylinder 3 is flush with the head section 22. Alternatively, it is also possible to make the feed cylinder 3 shorter or the head section 22 longer. Furthermore, it is also possible to form all of the functional sections provided for the valve device of the liquid dispenser on an insert element which is inserted or screwed into a recess in the valve block which runs particularly radially to the longitudinal axis of the feed cylinder 3.

According to a particular aspect of the present invention, the dispensing cannula 7 is not screwed into the valve block 1 via a threaded base, but is pressed into the valve block 1 via a preferably cylindrical press fit. Such an attachment of the dispensing cannula 7 to the valve block 1 proves to be particularly advantageous in particular with regard to the sterilizability of the liquid dispenser, since a considerably smaller gap is created between the two components compared to a threaded connection. As an alternative to pressing the foot area of the dispensing cannula 7 into the valve block 1 in this way, it is also possible to form an attachment on the valve block 1 similar to the hose pin 14, onto which the dispensing cannula 7 can be plugged. In order to enable particularly reliable sterilization of the liquid dispenser, the dispensing cannula can be pulled off the liquid dispenser.

The embodiment of a liquid dispenser shown in Fig.4 differs from the embodiment described above in connection with Fig.1 by a switching mechanism accommodated in the valve block 1. This switching mechanism comprises a recess 36 provided for receiving a valve slide element 35 (Fig.5). The recess 36 is designed here as a cylindrical through-bore and extends continuously from a front

side of the valve block 1 to a rear side of the same. A number of through-channels open into the peripheral wall of the through-bore. In the embodiment shown in Fig.4, these are a cylinder intake channel 37, a cylinder discharge channel 38, the intake channel 13 already described in connection with Fig.1, a flushing channel 39 and a ventilation channel 40. The cylinder intake channel 37 and the cylinder discharge channel 38 are designed as separate channels in the embodiment shown here. However, it is also possible to combine these two channels, as in the embodiment according to Fig.1, with a corresponding design of the valve slide element 35 (Fig.5).

The channels 37, 38, 39, 40 and 13 can be brought into an open position or a closed position by actuating the valve slide element 35, as described below in connection with Fig. 6. The flushing channel 39 is intended to return the fluid delivered via the delivery cylinder back into the vessel, particularly when the liquid dispenser is first put into operation or if the dispenser is not used for a long period of time, until no air bubbles appear in the suction hose or in the delivery cylinder.

According to a special aspect of the present invention, the flushing channel 39 opens into an annular space surrounding the hose pin 14. This advantageously makes it possible for the fluid returned via the flushing channel to flow back into the vessel along the outer wall of the hose attached to the hose pin 14 without splashing the vessel wall. To form this annular space, a cylinder pin 41 arranged coaxially to the hose pin 14 is advantageously provided in the embodiment according to Fig.4. This cylinder pin 41 enables a particularly even flow around the intake hose (not shown) and prevents the ventilation channel 40 from coming into contact with the returned fluid. The in-

The inner wall of the recess 36 forms a particularly smooth surface. The recess 36 can also advantageously be slightly conical, which results in an extremely reliable seal between the valve slide element 3 and the inner wall of the recess 36.

In the embodiment shown in Fig. 4, the valve slide element 35 is secured in the valve body 1 via a bayonet lock device. This bayonet lock device comprises a locking projection formed on the valve body 1. In order to enable particularly effective cleaning of the dispenser and in particular to enable particularly effective sterilization of the liquid dispenser, a special aspect of the invention provides that the entire valve and switching mechanism can be removed from the valve block 1 in a simple manner, preferably without the use of tools. As a result, the recess 36 provided for receiving the valve slide element 35 is accessible from the outside. The relatively large recess 36 also enables particularly effective access of a cleaning and/or sterilizing agent to the interior formed in the feed cylinder.

According to a further aspect of the present invention, the valve body 1 is provided with a plug-in device, via which the valve slide element 35 removed from the recess 36 can be plugged into the valve body 1 or the liquid dispenser in a preferably upright position. A switch flag 43 (Fig. 5) which is formed in one piece with the valve slide element 35 is preferably used as the plug-in section for this purpose. This switch flag 43 can be plugged into a corresponding groove formed on the valve block 1, so that it is possible to continue to place the disassembled liquid dispenser as a coherent assembly in a sterilization device without individual parts of the liquid dispenser lying loose in the sterilizer and possibly being swapped around.

The valve mechanism provided in the valve block 1 described in connection with Fig. 4 can also be used in a liquid dispenser in which the valve block 1 and the feed cylinder 3 do not form an integral structural unit. It is also possible to insert an insert element into the recess 3 6 formed in the valve block 1 instead of the valve slide element 35, which, for example, only contains two check valves and otherwise does not allow a switching function between a flushing mode, a feed mode and a blocking position. Such an insert element is provided, for example, in a basic version of the dispenser and can optionally be exchanged for a correspondingly designed valve slide element 3 5. The valve block 1 and the feed cylinder 3 then form a feed module, the special functional properties of which are only finally determined by using a corresponding valve slide element 3 5 or a corresponding insert element.

The valve slide element 35 shown in Fig. 5 is inserted into the recess 36 of the valve block 1 in a pivotable manner. The maximum pivoting range of the valve slide element 35 is limited by a stop device. According to a special aspect of the present invention, this stop device is formed by a bayonet lock device, which at the same time secures the valve slide element 35 in the axial direction. The valve slide element 35 comprises a pin section 44, the peripheral surface of which together with the inner peripheral wall of the recess 36 forms a slide system. By pivoting the pin section 44 into certain rotational positions, certain channels formed in the valve block 1 become active, i.e. continuous, or inactive, i.e. closed.

According to a particular aspect of the present invention, the valve mechanism also makes it possible to block the vessel ventilation. This is particularly useful in the case of slightly curvy

This prevents the corresponding vapours formed inside the vessel from escaping from the vessel when the pumped media are used. The vessel ventilation is only active when the device is switched to a dispensing state or, if applicable, to a rinsing state.

In order to prevent an undesirably high pressure from building up inside the vessel, the ventilation device can additionally be provided with a pressure relief valve device or a comparatively small pressure equalization bore. According to a particular aspect of the invention, the vessel ventilation device comprises a sintered granulate pin 45, which is inserted into the valve slide element 35.

A number of connecting paths are formed in the pin section 44 of the valve slide element 35, which are continuous in a corresponding switching position of the valve slide element 35.

An advantageous embodiment of the liquid dispenser, not only from an assembly point of view but also with regard to the sterilizability of the liquid dispenser, is provided by the fact that preferably all valves (check valves) are arranged in the valve slide element 35. In the embodiment shown in Fig. 5, three check valves, in particular formed by spring-loaded balls, are arranged inside the pin section 44. The respective valve seats of these check valves are formed in one piece with the valve slide element 35 according to a special aspect of the present invention. The dispensing cannula 7 is also advantageously formed in one piece with the valve slide element 35. The switching flag provided on the valve slide element 35 enables a particularly ergonomic switching of the valve slide element 35 and also represents a display device by means of which the respective operating state of the fluid dispenser can be easily recognized.

The functioning of a preferred embodiment of the valve slide element 35 is described below in conjunction with Fig.6. The pin section identified in Fig.6 by the reference number 44 can be pivoted by 30° both clockwise and counterclockwise. In the position shown, the pin section 44 is in a "dispensing position" and enables the fluid to be sucked in via the intake channel 13, shown here in simplified form as an arrow, and the cylinder intake channel 37. During the suction process, the intake valve ball 10 assumes an open position and enables fluid to pass through the check valve, shown here in simplified form. When the delivery piston is lowered, the fluid is released into the cylinder output channel identified by the reference number 38, with the output valve ball 16 entering an open position and enabling fluid to pass to the output cannula 7. While the fluid is being sucked out of the vessel via the intake channel 13, ambient air can flow into the vessel via the sintered granulate pin 45 shown in Fig. 5 and via the ventilation channel 40. If there is excess pressure inside the vessel, a corresponding amount of gas can also escape from the vessel via the passages 40, 45. If the pin section 44 is pivoted 30° anti-clockwise in the schematic diagram shown here, the connection between the discharge cannula 7 and the cylinder discharge channel 3 8 is interrupted and the flushing channel 3 9 is connected to the interior of the delivery cylinder via an additional flushing check valve 46. In this switching position, it is possible to recirculate fluid sucked in via the intake channel 13 through the delivery cylinder back into the vessel via the flushing channel 3 9 by means of appropriate pumping strokes of the delivery piston.

In the embodiment of the valve device shown in Fig.6, there is also a connection between

the interior of the vessel and the surrounding area via the sintered granulate plug 45.

If the pin section 44 is pivoted clockwise by an angle of 30° from the position shown in Fig.6, the pin section blocks the intake channel 37, the discharge channel 38, the discharge cannula 7, preferably also the ventilation channel 40, the intake channel 13 and possibly also the flushing channel 39. This prevents an undesired escape of the fluid or vapors formed by it in a particularly reliable manner. In addition, it is advantageously ensured that in the event that the delivery cylinder breaks or is separated from the valve block 1, the vessel can still be securely closed. With regard to Fig.6, it should be clarified that the fluid paths shown here are only shown schematically and advantageously do not run in one plane. The check valves shown here are arranged inside the pin section in such a way that the individual closing balls can be moved radially to the longitudinal axis of the pin section 44. According to an alternative, advantageous embodiment of the invention, however, three longitudinal bores are formed in the pin section 44, which are parallel to one another and arranged parallel to the longitudinal axis of the pin section, in which the valve balls are accommodated in such a way that they can be moved in the longitudinal direction of the pin section 44. Corresponding valve springs are also inserted into these longitudinal bores.

According to a preferred embodiment of the invention, the recess 3 6 is formed by a glass or ceramic bushing injected or, for example, molded into the valve body 1. This advantageously enables a particularly smooth movement of the valve slide element 3.

nc

Instead of the previously described design of the valve slide element 35 as a rotary slide, it is also possible according to an alternative embodiment of the invention to bring this valve slide element into different switching positions by moving it along its longitudinal axis. Advantageously, a through-hole is provided on the valve slide element 35, with which a lock, in particular the shackle of a padlock, can be brought into engagement, whereby an unauthorized removal of a liquid from the vessel can be prevented. Since the valve slide element 35 also blocks the fluid connection between the dispensing cannula 7 and the vessel, no fluid can be sucked out of the vessel when the valve slide element 35 is in a blocked position.

Furthermore, since the vessel vent is also blocked when the valve slide element 35 is in the closed position, neither gases nor vapors can escape from the vessel and no particle exchange with the environment can take place.

According to a further aspect of the present invention, the valve slide element 35 is designed in such a way that it can be brought into a switching position in which the pump unit formed from the delivery cylinder 3 and the delivery piston 4 can also be used to suck in the fluid from an external vessel. For this purpose, a hose pin is advantageously formed in one piece with the valve body 1, onto which a hose leading to the external vessel can be plugged.

The invention is not limited to the embodiments described above. For example, it is also possible to form a fastening device intended for fastening the valve block 1 to a vessel in one piece with the valve block 1. Furthermore, it is also possible to use a fastening device instead of a valve block 1 injected as part of a hot runner injection process.

ten plastic material, especially a thermosetting
Casting material to form the integral structural unit.

All features arising from the description and the drawing, including the structural details, can also be essential to the invention in any combination.

Claims (39)

Protection claims 1. Liquid dispenser with a valve block (1) that can be placed on a vessel and has a suction valve (2), a delivery cylinder (3) connected to the suction valve (2), in which a delivery piston (4) that can be connected to an actuating device (5) is slidably received, and a dispensing device (6) for the liquid that can be connected to the valve block (1), characterized in that the valve block (1) and the delivery cylinder (3) form an integral structural unit. 2. Liquid dispenser according to claim 1, characterized in that the conveying cylinder (3) is a glass cylinder. 3. Liquid dispenser according to claim 1 or 2, characterized in that the valve block (1) consists of plastic, in particular polypropylene. 4. Liquid dispenser according to at least one of claims 1 to 3, characterized in that the glass cylinder is surrounded by a protective tube (8) made of plastic, in particular polypropylene, which is integral with the valve block (1). 5. Liquid dispenser according to at least one of claims 1 to 4, characterized in that the glass cylinder is injected into the valve block (1) and the protective tube (8). 6. Liquid dispenser according to at least one of claims 1 to 5, characterized in that the valve block (1) is designed in a skeleton construction with spaced webs (9) which are formed by recesses. 7. Liquid dispenser according to at least one of claims 1 to 6, characterized in that the valve block (1) is formed by a mold space (27), the mold halves (25, 26) of which can be brought into an open position or a closed position in a direction transverse to a longitudinal axis of the conveyor cylinder (3). 8. Dosing cylinder with an inner wall that is largely resistant to a viscous conveying medium, in particular made of a glass material, for a liquid dispenser to form a conveying chamber for receiving a conveying piston (4) in a sliding manner, characterized in that a dosing cylinder outer wall is formed by a plastic body formed in the course of a plastic molding process, and that a conveying cylinder (3) forming the inner wall is accommodated in the plastic body. 9. Dosing cylinder according to claim 8, characterized in that the plastic body is formed by a plastic injection molding process, in particular a hot runner injection molding process. 10. Dosing cylinder according to claim 8 or 9, characterized in that the plastic body has a wall thickness which is at least 1/10 of the wall thickness of the feed cylinder (3). 11. Dosing cylinder according to at least one of claims 8 to 10, characterized in that the plastic body is made of a transparent material. 12. Dosing cylinder according to at least one of claims 8 to 11, characterized in that the plastic body has a substantially cylindrical shape. 13. Dosing cylinder according to at least one of claims 8 to 12, characterized in that the plastic body is formed by a molding tool which has a mold space (27) formed by at least two mold halves (25, 26), wherein the at least two mold halves (25, 26) can be brought into an open position by relative movement along a mold opening axis running essentially transversely to the longitudinal axis of the conveyor cylinder (3). 14. Dosing cylinder according to at least one of claims 8 to 12, characterized in that the plastic body is formed by a molding tool which has a molded part which delimits a molding space and which is used for demolding the plastic material body is movable relative to it in the direction of the longitudinal axis of the plastic body. 15. Dosing cylinder according to at least one of claims 8 to 14, characterized in that a foot base (33) is provided on the plastic body, and that the foot base (33) is formed integrally with the plastic body. 16. Dosing cylinder according to at least one of claims 8 to 15, characterized in that the dosing cylinder has a head section (22), and that the head section (22) is formed integrally with the plastic body. 17. Dosing cylinder according to at least one of claims 8 to 16, characterized in that the plastic body comprises a protective casing (8) extending continuously between the head section (22) and the foot base (33). 18. Dosing cylinder according to at least one of claims 8 to 17, characterized in that the dosing cylinder is provided with a scale and that the scale is encased by the plastic body. 19. Dosing cylinder according to at least one of claims 8 to 19, characterized in that the scaling is formed on the outer surface of the plastic body. 20. Dosing cylinder according to at least one of claims 8 to 19, characterized in that an end flange (34) formed integrally with the plastic body is provided in a front end region of the dosing cylinder, the end flange (34) extending radially inwards to the longitudinal axis of the dosing cylinder. 21. Dosing cylinder according to at least one of claims 8 to 20, characterized in that the end flange (34) forms a through opening which has a smaller diameter than the inner diameter of the feed cylinder (3). 22. Dosing cylinder according to at least one of claims 8 to 21, characterized in that the plastic body forms an extension section which extends beyond the feed cylinder (3) in the axial direction of the feed cylinder (3). 23. Dosing cylinder according to one of claims 8 to 22, characterized in that the extension section is arranged coaxially to the longitudinal axis of the feed cylinder (3) and forms a guide section for guiding a feed piston (4). 24. Dosing cylinder according to one of claims 8 to 23, characterized in that a valve block (1) provided for receiving a valve device (2) is formed integrally with the plastic body. 25. Dosing cylinder according to at least one of claims 8 to 24, characterized in that the valve block (1) and the plastic body are formed as an integral structural unit by a plastic injection molding process. 26. Dosing cylinder according to at least one of claims 8 to 25, characterized in that the valve block (1) is formed by a mold space formed by an at least two-part molding tool, wherein a separating surface of the molding tool runs essentially parallel to the longitudinal axis of the feed cylinder (3). 27. Dosing cylinder according to one of claims 8 to 26, characterized in that a lower region of the valve block (1) is formed by a mold core (29) which is withdrawn from the valve block (1) in the axial direction of the feed cylinder (3). 28. Device for producing a liquid dispenser comprising a feed cylinder and a valve block with a molding chamber in which the valve block is formed from a plastic material by plastic injection molding and from which the valve block can be removed after the plastic material has hardened, characterized in that the molding chamber is designed in such a way that during the plastic injection molding a plastic body provided for receiving a feed cylinder (3) is formed integrally with the valve block (1). 29. Device according to claim 28, characterized in that the mold space comprises a section for receiving a glass cylinder forming the conveyor cylinder (3), so that the glass cylinder can be encapsulated by a plastic material forming the plastic body. 30. Device according to claim 28 or 29, characterized in that a mold core (28) is provided for centering the glass cylinder. 31. Device according to at least one of claims 28 to 30, characterized in that a preheating device is provided for preheating the glass cylinder before it comes into contact with the plastic material. 32. Device according to at least one of claims 28 to 31, characterized in that the glass cylinder sits in a tight fit on the mold core (28). 33. Device according to at least one of claims 28 to 32, characterized in that the molding space is designed such that the glass cylinder is molded around by the plastic material in a front end region. 34. Device according to at least one of claims 28 to 33, characterized in that the molding space is designed such that the plastic material can be injected into the molding space (27) at different locations. 35. Device according to at least one of claims 28 to 34, characterized in that the molding chamber is designed such that different types of plastic material can be injected into the molding chamber (27) at different locations. 36. Device according to at least one of claims 28 to 35, characterized in that an injection device is provided for injecting a transparent or translucent plastic material into the region of the mold space (27) intended to receive the glass cylinder. 37. Device according to one of claims 28 to 36, characterized in that the molding chamber (27) can be brought into an open position by opening it in a direction transverse to the longitudinal direction of the glass cylinder. 38. Device according to at least one of claims 28 to 37, characterized in that the mold space (27) is delimited by two mold halves (25, 26) delimiting an outer region of the valve block and by two core elements (28, 29). 39. Device according to one of claims 28 to 38, characterized in that the two core elements (28, 29) can be inserted into the mold space (27) delimited by the mold halves.