JP2013543560A - Metering pump - Google Patents

Abstract

The present invention relates to a metering pump for a metering device for dispensing liquid, which can be connected to a storage container, comprising a cylindrical pump body and an actuating body.
[Selection] Figure 1

Description

  The present invention relates to a metering pump for a metering device for dispensing a liquid, which can be connected to a storage container and comprises a cylindrical pump body and an actuating body.

Metering pumps for dispensing liquids that can be connected to a storage container are known from the prior art.
Such metering pumps consisting of a cylindrical pump body, an actuating body and a closure cap are known from EP 0 473 892 A2 and EP 1 466 668 A1. An essential element of the metering pump according to the above-mentioned European patent application is a configuration in the form of a pump body in the form of a hollow cylinder having two parts, and the internal hollow cylinder to which the piston is guided is the interior of the hollow cylindrical pump body. Attached to. Sealing to the storage container is achieved by a gasket placed inside it.

  A similar solution is known from WO 97/18902, in which a sealing ring is likewise provided for sealing between the storage container and the hollow cylindrical pump body.

  However, such a configuration is shown to display insufficient reliability with respect to imperviousness to air penetrating during the metering process. In addition, if the storage container is used at high transient back pressure, there is a problem during quantification.

  The object of the present invention is therefore medical, medical, which can be connected to a storage container and is achieved even under disadvantageous conditions, which are impervious and reliable to air penetrating during the quantification process And metering pumps for cosmetic liquids and cosmetics and in the food sector (eg for food supplements, herbs / spices, etc.).

This object is achieved by the features of patent claim 1. The dependent claims reveal preferred developments.
According to the invention, a metering pump that can be connected to a storage container, as already known in the art, for example from EP 0 473 892 A2, EP 1 466 668 A1 or WO 97/18902, is a seal for sealing. Provided according to claim 1 wherein the ring is improved to be provided between the outside of the piston and the inside of the pump body on the pump body on itself. Furthermore, the metering pump according to the invention is distinguished by a valve part provided at the open end in the direction of the storage container, in which the inlet valve cooperates with a ball arranged in the valve seat according to the invention. .

  It is achieved by a combination of these means that very high permeability is achieved even under unfavorable conditions during the metering process, ie at high temperatures and counter pressures. Furthermore, the operation of the metering pump is rather that of several generally 3-4 pumping processes so that the pumping process does not have to be performed many times as is normal in the prior art for the filling process. It will be shown that the configuration according to the invention is possible even afterwards so that it is reliable and allows complete measurements.

  A particularly advantageous embodiment of the metering pump is that, inside the valve part starting from the inside, a longitudinally extending support element is provided for the definition of the upper passage of the ball during operation of the metering pump. As a result, a very reliable guide of the ball in the space spanned by the valve seat and the support element is possible. In particular, this measurement clearly leads to the fact that, as already mentioned above, a very reliable operation is possible with the metering pump according to the invention. For this embodiment, it will become clear that it is particularly advantageous if at least one, preferably two, particularly preferably three, support elements are provided. These support elements are preferably configured to be integrally (integrally) connected to the inside of the internal hollow cylinder that defines the valve portion. Thereby, preferably these support structures are manufactured integrally with the valve seat and the inner hollow cylinder, at least the valve part, preferably by an injection molding process.

The advantage of the thin wall configuration in this region is the higher flexibility of this valve part.
This increased flexibility is the “suction / recovery” produced by the inner bag (located in the storage container) after actuation of the pump (inner bag returning to its relaxed form instead of remaining in its folded form) It is possible to counter this tendency.

  This means that the contact area of the valve wall with the ball is more tightly sealed due to increased flexibility and prevents air ingress in the bottle direction. In the case of thicker walls, the result is that there is a gap in the area between the contact areas of the ball against the valve, so that air enters. This is especially the case with balls that are not optimally round or irregularly coated.

In the case of support elements, all possibilities that are known per se in the art and lead to ball stabilization are included. Suitable support elements are those configured in a wedge shape.
More importantly, it is clear that at least the valve part is configured such that the wall thickness of the valve part is in the range of 0.2 to 1.0 mm, preferably in the range of 0.3 to 0.5 mm. become. Therefore, a simplified production in an injection molding process is advantageous. The reproducibility of the shape of the support element is increased as a result, thus allowing the correct function and mobility of the ball. Thus, the essential element associated with this embodiment is the configuration in the form of a thin wall that is within the indicated limits. Obviously, if the upper limit of 1.0 mm is exceeded, this leads to a lack of seal in subsequent use. Furthermore, the stiffness is very high so that the flexibility of the wall is too small to ensure the ball is sealed. If the thickness is smaller than 0.2 mm, sufficient stabilization cannot be achieved.

  In a further preferred embodiment, it is proposed to apply a ball. The application of the ball takes place in a thin layer placed around the ball over the entire surface. A suitable material for this is in particular LD-PE (low density polyethylene). Improvement of the measurement effect is achieved by this measure. The coating with this material, which is approved for medical applications, allows the approval of pharmaceuticals in markets with particularly strict regulations.

The ball itself can be composed of, for example, stainless steel, or a ball coated with silver that is subsequently sterilized.
The gasket proposed in accordance with the present invention is a seal ring in a preferred embodiment.

  The seal ring according to the present invention is arranged inside a hollow cylindrical pump body portion indicating the direction of the working body. Thereby, the arrangement should be chosen such that the highest possible sealing effect is achieved relative to the piston guided inside the hollow cylinder. The seal ring can also be present as an integral element of the corresponding pump body part.

  Thus, in an advantageous manner, the seal ring is spaced from the outer wall of the piston and is configured to have a suitable seal lip. Thus, impermeability to the piston is achieved by these sealing lips. Thereby, the sealing lip can be configured as a separate individual lip and indicate the direction of the working body. The seal ring can thereby have at least one, preferably 3 to 5, lips.

  The development of the present invention is that, for secure attachment of the seal ring inside the hollow cylindrical pump body part, the seal ring is configured with a U-shaped contour, one of the U-shaped legs on the inside of the pump body part. It is proposed to engage with the groove. The other of the U-shaped legs is used for a sealing effect. The other of the U-shaped legs is spaced from the outer surface of the piston and can be configured to produce a sealing effect via the lip.

  From a material selection point of view, basically all materials can be used and are generally used for gaskets. Thereby, the choice of material depends on the safety of the respective field of use. Thermoplastic resins and thermoplastic elastomers are possible. Examples include PTFE (polytetrafluoroethylene), PU (polyurethane), polyamide (PA), polyethylene terephthalate (PET), LD-PE (low density polyethylene), HD-PE (high density polyethylene) and PP (polypropylene). It is.

  The metering pump according to the invention can naturally be stabilized as in the prior art and can have an additional gasket for sealing against the storage container. Thereby, the gasket is preferably arranged in one piece between the inner hollow cylinder and the cylindrical pump body part on the one hand and between the storage containers not shown on the other hand.

  The cylindrical pump body is preferably formed from a plastic material such as polypropylene (PP) or polyethylene (PE). What is important for the selection of the material is thereby the safety of the medical and pharmaceutical and the safety of the material in the food sector. Thus, the inner surface of the cylindrical pump body can have a coating for sterilization purposes.

The invention also includes an embodiment similar to EP 1 466 668 A1 in which an internal hollow cylinder forming a pressure chamber can be favored.
The metering pump according to the invention naturally has an operating body connected to the piston and the cylindrical pump body. Thereby, the configuration of the operating body is similar to that based on the prior art. Reference is made in relation to EP 0 473 892 A2, EP 1 466 668 A1 and WO 97/18902.

  All storage containers of the prior art are basically possible as storage containers that can be connected to a metering pump. Reference is made in connection with the literature mentioned in the previous paragraph. For example, a flexible inner bag or a container with a drag piston should be able to operate without air equalization. In addition to a cylindrical container made from a suitable plastic material, a bag of plastic material integrated into another container is preferred. Lower pressures should be expected when using a drag piston.

The storage container is preferably connected to the metering pump via a snap closure or screw.
The invention is explained in more detail below with reference to the drawings.

FIG. 1 shows an embodiment with a sealing element according to the invention. FIG. 2 shows the sealing element of FIG. 1 according to the invention in an enlarged form. FIG. 3 shows an embodiment in which the sealing element is configured in a U-shape. FIG. 4 shows the sealing element of FIG. 3 according to the invention in an enlarged form. FIG. 5 shows a cut-out configuration of the valve region with respect to the sequence of FIGS. 1, 2 and 3 showing various operating states. FIG. 6 shows the dimensions of the valve region.

  FIG. 1 schematically shows the configuration of a metering pump according to the invention, a cylindrical pump body 1 having an actuating body 20 is shown for a metering pump. An actuating body 20, preferably composed of the same material as the cylindrical body, for example PE, is connected to the pump body 1, for example via a snap closure or screw. In FIGS. 1, 2, 3 and 4, the storage container is not shown because it is not essential to understanding the present invention. For this purpose, reference is made to EP 0 473 892 A2, EP 1 466 668 A1 and WO 97/18902 for a description of the working body 20.

  In FIG. 1, as is known from the prior art, a cylindrical pump body 1 of a metering pump having an actuating body 20 is shown. Thereby, the cylindrical pump body 1 is composed of a hollow cylindrical pump body part 2 which opens in the direction of the storage container and a second hollow cylindrical pump body part 3 which opens in the direction of the working body 20. Thereby, the groove arranged in the inner wall of the part 3 is indicated by reference numeral 15. The inner hollow cylinder 4 is mounted between the pump body parts 2 and 3. The attachment of the inner hollow cylinder 4 of the pump body parts 2 and 3 is effected by engagement in a groove in the embodiment according to FIG. As shown in FIG. 1, the piston 5 is guided to the inner hollow cylinder 4. As known in the prior art, the piston 5 is supported inside the hollow cylinder 4 via a spring 9. The inner hollow cylinder 4 has an inlet valve 6, which is configured to have a ball 8 that cooperates with a valve seat 7. The valve area is indicated by 30. In order to ensure a hermetic seal between a storage container (not shown) and its surroundings, a gasket device 10 is provided below the drawing. The sealing element 11 essential for the present invention is configured in the form of a ring, as can be seen in particular in FIG. 2, and is spaced inside the hollow cylindrical pump body part 3, preferably with respect to the outer wall of the piston 5. It is attached.

  In order to improve the sealing effect, a sealing lip 12, 12 'is provided as can be seen from FIG. 2 which produces a reliable seal against air penetrating during the pumping process. Thereby, the present invention includes embodiments in which at least one sealing lip is provided.

  In a variant of the embodiment as described in FIG. 1 or 2, FIG. 3 shows that the sealing element 11 is configured in a U shape. In this embodiment, the seal ring 11 is attached by one U-shaped leg of the groove 15 inside the pump body portion 3. The second U-shaped leg functions as a sealing element for the outer wall of the piston 5. In the embodiment according to FIG. 3, the sealing lips 12, 12 ′ are provided to allow optimal guidance of the piston and seal inside the hollow cylinder 4.

  In FIG. 4, the partial area of the embodiment shown in FIG. 3 is shown enlarged. The seal lips 12, 12 'are provided in order to improve the sealing effect. These allow for a positive seal against air penetrating during the pumping process. Here, the seal ring 11 exists in a U-shape.

FIG. 5 shows a cut-out configuration of the valve region 30 with respect to the sequence of FIGS. 1, 2 and 3 showing various operating states during operation.
In FIG. 5, the support element 31 is shown in a wedge shape. The support element 31 and the valve seat 7 are configured integrally with the inner surface of the inner hollow cylinder 4. Such a configuration is preferably accomplished by forming at least one internal piston portion defined by an integral valve region 30 made of a suitable plastic material by an injection molding process. As described above, the configuration of the valve region 30 achieves that a reliable closure of the valve is achieved during operation of the piston, as shown in the sequence of FIGS. 2 and 3 show the operational modes of the wedge-shaped support element 31 which lead to a change in the position of the ball 8 during the operation of the metering pump and the reliability of the ball 8 and the defined fixation of the ball 8. .

  A further essential element of the invention resides in the valve region 30 formed by a relatively thin walled inner hollow cylinder 4, as shown in FIG. The wall thickness of the valve portion 30 of the inner hollow cylinder 4 is preferably in the range of 0.2 to 1.0 mm, particularly preferably in the range of 0.3 to 0.5 mm. With this thin material thickness, it is shown that the valve seat achieves optimum adaptation of its shape to the ball, but with sufficient stability and sufficient flexibility to hold the ball firmly. It was done. As a result, sealing is achieved. According to the invention, the metering pump is thus configured such that the above dimensions of the inner hollow cylindrical wall are maintained at least in the region of the valve region.

Claims (13)

A metering pump for a metering device for dispensing liquid, which can be connected to a storage container,
From a first hollow cylindrical pump body part (2) opening in the direction of the storage container, a second hollow cylindrical pump body part (3) opening in the direction of the working body, and an internal hollow cylinder (4) opening at both ends A cylindrical pump body (1) configured;
The cylindrical pump body (1) is mounted between the two first hollow cylindrical pump body portions (2) and the second hollow cylindrical pump body portion (3), and includes one piston (5) and the cylindrical pump body (1). ) To the operating body (20) connected to
A sealing element (11) for sealing the piston (5) includes an outer surface of the piston (5), an inner surface of the second hollow cylindrical pump body portion (3) inside the second hollow cylindrical pump body portion (3), and Placed between
The inner hollow cylinder (4) has a valve part (30) at its open end in the direction of the storage container, the inlet valve (6) cooperating with a ball (8) arranged in the valve seat (7). pump. The metering pump according to claim 1,
Inside the valve part (30) starting from the inside, a longitudinally extending support element (31) is arranged for the definition of the upper passage of the ball (8) during operation of the metering pump. The metering pump according to claim 2, wherein
Metering pump in which at least one, preferably two, and particularly preferably three support elements (31) are provided in a wedge shape. In the metering pump according to any one of claims 1 to 3,
The metering pump, wherein the thickness of the valve part (30) is in the range of 0.2 to 1.0 mm, preferably in the range of 0.3 to 0.5 mm. In the metering pump according to any one of claims 1 to 4,
A metering pump in which at least the valve part (30) of the internal hollow cylinder (4), the valve seat (7) and the support element (31) are integrally formed. The metering pump according to claim 5, wherein
A metering pump, wherein at least the valve part (30) is manufactured by an injection molding process. In the metering pump according to any one of claims 1 to 6,
The ball (8) is a metering pump with a coating. In the metering pump according to any one of claims 1 to 7,
The metering pump, wherein the sealing element (11) is a seal ring. In the metering pump according to any one of claims 1 to 8,
The sealing element (11) is spaced from the outer surface of the piston (5) and has at least one lip, preferably two (12, 12 ′) indicating the direction of the piston (5). pump. The metering pump according to claim 9, wherein
The sealing element (11) has a U-shaped profile and one U-shaped leg engages a groove (15) arranged inside the second hollow cylindrical pump body part (3). , Metering pump. The metering pump according to any one of claims 1 to 10,
The sealing element is made of polyamide (PA), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PP) and / or polyurethane (PU), or made of these materials. The metering pump. The metering pump according to any one of claims 1 to 11,
A metering pump, in which the gasket (10) is arranged in one piece between the inner hollow cylinder (4) and the first hollow cylindrical pump body part (2) on the one hand and between storage vessels (not shown) on the other hand. The metering pump according to any one of claims 1 to 12,
A metering pump, provided with a spring (9), which is attached to the piston (5) and supported inside the internal hollow cylinder (4).

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