EP0686597A1

EP0686597A1 - An apparatus with a container and pump for vacuum unloading of contents

Info

Publication number: EP0686597A1
Application number: EP94810342A
Authority: EP
Inventors: Wilhelm A. Keller
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-06-09
Filing date: 1994-06-09
Publication date: 1995-12-13
Also published as: JPH0849654A

Abstract

The apparatus comprising at least one container (1) which is removably attached to the inlet (9) of the pump body (10) for vacuum unloading of its content and is closed at its outlet end (7). The cylindrical wall (1W) of the container (1) is substantially thinner than the wall of a cartridge with equal diameter for dispensing apparatus being subjected to pressure.

Description

This invention relates to an apparatus comprising at least one container and pump for vacuum unloading of the content of the container. In the field of reactive systems such as epoxies, polyurethanes, silicones and polysulphides, in particular of two components, it is necessary to meter the components relative to each other and to mix and dispense them.
Hitherto, there have been two methods of mechanising this process, one being the use of pre-filled two component metering and mixing disposable cartridges, which have volumes up to about 600 ml, and the other through the use of mixing and dispensing machines which mostly require the two individual chemical components to be decanted out of disposable cans and drums, mainly ranging from 1 litre to 25 litres, into metering and mixing machine containers. In the latter case the decanting of these typically viscose and thixotropic chemicals can cause unwanted air to be entrapped within the chemical. In the context of this description, the handling of two components is disclosed but the invention applies also to a container and pump for one component as well as for an apparatus with more than two components and containers.
It is, based on the above mentioned state of the art, the purpose of this invention to provide for an apparatus with a container and pump for vacuum unloading of its content without cavitation and which reduces the production cost of the container and lowers the impact of container and small can disposability upon the environment and eliminates the need to decant from cans and drums. This purpose is attained with the characteristical part of claim 1. In a preferred embodiment the entrapping of unwanted air is precluded.
The invention will be explained in more detail hereinafter with reference to drawings of embodiments.

Figs. 1A and 1B show in a sectional view two variants of a first embodiment of the invention,
Figs. 2A and 2B show in a sectional view two variants of a second embodiment of the invention, and
Fig. 3 shows in a sectional view a third embodiment of the invention.

Referring to Fig. 1A, a cylindrical container 1 is shown with a removable sealing lid 2 which seals via a lip 3. A piston 4 is in a sliding fit within the container 1 having a skirt 5 the length of which both seals and holds the piston 4 from tilting. The center of the piston 4 having, preferably but not necessarily, a protruding dome-like shape 6 which fits within the contour of the container outlet 7 of the container so as to provide a close fit between the two parts, thus enabling a maximum dispensing of the material.
In the present description interface 80 at the outlet end 7 of container 1 is defined as the plane between the material in the pump inlet 9 and the material in the outlet 7 of the container. It is important that at the moment of exchanging the containers no gas or air enter the pump inlet. The connecting means 8 comprises a bayonet or threaded type connecting part 24 which fits into the counterpart 25 at the pump inlet 9 attached to the pump body 10. An example of a portable metering and mixing machine housing such pumps is disclosed in the European Patent Application No. 94 81 0001.1. The outlet 7 of the container includes a fitting section 11B to prevent excess material from raising up to the bayonet area and airtight means 11 for preventing air to enter into the pump. For this purpose, container outlet 7 forms together with the corresponding part of inlet 9 of the pump body a fitting section 11B as well as a vacuum tight seal through the use of a sealing ring 11 as it seals within the pump inlet 9.
The interface 80 of the container may also comprise an injection moulded or a welded plastic foil or foil laminate sealing face 12 of the container outlet 7 which presses against the surface of the residue of liquid in the pump inlet during connection when exchanging an empty container for a full container so as to avoid air entrapment and to cause any excess liquid or air to be expelled from the circular vent channel 13 out of the vent hole 13A and the valve 17. Said vent channel is aranged between the fitting section 11B and sealing ring 11.
For use, the sealing face 12 must be somehow opened and therefore the pump or its interface must comprise means for enabling this action. As one means, the sealing face may be imploded by vacuum caused by the metering pump. As another means according to a preferred embodiment of the invention the sealing face is partially rotated against a cutting device 14 during the fitting of the container 1 into pump inlet 9. This cutting device may be one knife or several knifes, a tooth or several teeth.
The inlet end of the container is closed by a sealing lid 2 which comprises preferably a pierceable area 18 so as to allow atmospheric pressure to be maintained above the piston 4 when the chemical contents 15, within container 1, are drawn down by vacuum through the action of the pump within the pump body 10. It is also possible to provide the sealing lid 2 with a - not shown - plug like closure member.
The piston 4 follows the chemical contents 15 down as they are drawn into the pump so as to eliminate cavitation and at the same time minimises chemical residue on the inner wall of the container. Finally, the piston is drawn to the extent of its movement having facilitated, by its domed shape, the complete displacement of the chemical from the container. The wall 1W of the container 1 is preferably made of plastics material and is either translucent or transparent such that the level of the piston may be viewed through the wall of the container at any time. A graduated scale 27 can be arranged on the outside of the container, indicating the volume of the chemical contents which remains within the container at any time during its use.
During the reloading stroke of the pump, the piston 4 is subjected to a pressure differential between the vacuum inside the container and atmospheric pressure at the back of the piston. In a preferred embodiment the pressure differential causes an upper sealing lip 16A of the piston skirt 5 to be flared outwards to aid the sealing of the piston 4. A lower piston skirt lip 16B wipes the container wall as the piston moves downwards. The pressure differential between the inside and the outside of the container, during the pump operation, causes the container walls to collapse slightly so as to form a tighter fit between the inner container walls and the piston skirt lip 16B for improved sealing.
Fig. 1B shows in a variant of Fig. 1A container 1 comprising an alternative sealing arrangement at the wider inlet end of the container in the form of a plastic foil or foil laminate diaphragm 19 welded to the container and capable of being punctured easily so as to form a container vent to atmosphere.
Alternative conditions are shown in Fig. 2A whereby container 20 comprises an alternative form of a connecting means 21 which has bayonet connections 22, 22A on the cylindrical wall 23 of the container and at the corresponding wider pump inlet 26 and not at its reduced diameter neck as according to Figs. 1A and 1B, whereas interface 80 is situated at the same place as in the previous embodiments. Fitting section 11B, sealing ring 11, vent channel 13, vent hole 13A, and valve 17 are the same as in the previous embodiments. Also this embodiment comprises the variants of container inlet end sealing means as in the previous embodiment.
As mentioned before, the surface of the piston facing the content may be flat. As a further alternative, the container 20 of Fig. 2B does not include a piston and is intended for use with low viscosity liquids.
Figure 3 shows a further embodiment with a larger container 30 comprising a piston 31 with a skirt 29 and a dome 32, the latter of which can have another shape or be omitted. The container is closed at its inlet end by a sealing lid 33. In this case of a large container and therefore large piston, it might be useful to apply low pressure air to the back of the piston in order to overcome frictional losses during transfer of the liquid to the pump. For this purpose sealing lid 33 is provided with a sealed air inlet 34. Fitting area 11B, sealing ring 11, vent channel 13, vent hole 13A, and valve 17 are the same as in the previous embodiments. Also this embodiment comprises the variants of container inlet end sealing means as in the previous embodiment.
As the large container is mounted on a stand or rucksack it is required that a pipe or hose 35 be connected to the pump inlet 9. In a first variant, the pipe or hose 35 is fixedly connected to the pump inlet 10, the interface 81 is situated between the outlet 36 of the container and the inlet end 37 of the pipe or hose. The inlet end 37 of the hose comprises a coupling piece 38 having ribs 39 and a ring 40 for retaining hose 35.
The connecting means 41 and 42 at the container outlet end, resp. pipe or hose inlet end, are as in the previous examples of the bayonet or threaded type. Also this embodiment comprises the variants of container inlet end sealing means as in the previous embodiment. Fig. 3 further shows a collecting dish 43 fastened below the vent channel 13. If this collecting dish has an appropriate volume, valve 17 may be omitted.
It might be appropriate to fasten pipe or hose 35 directly to the outlet of the container and to provide the outlet end 44 of hose 35 with a coupling piece 38A having ribs 39 and ring 40 and a flange comprising part 41A of the connecting means, cooperating with part 42A of it at the pump inlet 9. In this case interface 82 is situated between the pipe or hose outlet end 44 and pump inlet 9. Both interfaces 81 and 82 may be provided with an injection moulded or welded plastic foil or foil laminate upper sealing face 12 which presses against the surface of the residue of liquid in the pump or pipe or hose inlet, whereby either the pipe or the coupling piece 38 or 38A or pump inlet 9 is provided with cutting device 14.
It follows from the above description that the pipe or hose 35 can also be connected via connnecting means 41 and 42 to the container as well as to the pump inlet.
Thus, a chemical packaging apparatus is proposed which attaches directly to a metering and mixing machine in order to eliminate decanting and allowing package exchange without air entrapment, the principle of which can ultimately be applied to all sizes of containers and which uses the vacuum caused by a pump to draw out the contents in an efficient manner. This vacuum transfer enables thin wall containers to be used, as opposed to the thick wall required for cartridges and containers which are subjected to pressures up to 15 bars. For example, at a typical cartridges/container having a diameter of 70 mm and being submitted to a pressure of 10 bar, the thickness of its wall can be reduced by about 40%, in general between 1/3 to 1/2 if working with vacuum transfer. It allows further the container to be refilled with relatively simple equipment by the professional user and to be reused as often as required, thus lowering the impact upon the environment in terms of the relative savings in content volume/container weight ratios against both cartridge and cans/containers and improved disposability/use ratios.

Claims

An apparatus comprising at least one container and pump for vacuum unloading of the content of the container, characterized in that the container (1, 20, 30) is removably attached to the inlet (9, 26) of the pump body (10) or to a pipe or hose (35) connected to said inlet (9, 26) of the pump body (10) and is closed at its outlet end (7).
The apparatus of claim 1, characterized in that the cylindrical wall (1W, 23) of the container (1, 20, 30) is thinner than the wall of a cartridge with equal diameter for dispensing apparatus being subjected to pressure.
The apparatus of claim 1 or 2, characterized in that the interface (80, 81, 82) at the outlet end (7) of the container or the pipe or hose (35) comprises vacuum tight sealing means (11), a diaphragm (12) closing the outlet end and that the connecting means (8, 21) at the interface (80, 81, 82) comprises fastening means (24, 22, 41, 41A) cooperating with its counterparts (25, 22A, 42, 42A) at the inlet (9, 26) of the pump body (10), or the inlet (37) of pipe/hose (35).
The apparatus of claim 3, characterized in that the fastening means is a bayonet or thread type fastener (24, 25; 22, 22A, 41, 41A, 42, 42A) arranged either at the reduced diameter outlet end (7) of the container and at the corresponding pump inlet (9) or pipe/hose (35) inlet (37), or at the cylindrical surface (23) of the container and at the corresponding pump inlet (26).
The apparatus of claim 3, characterized in that the sealing diaphragm is an injection moulded or a welded plastic foil or foil laminate (12), said foil or foil laminate being suitable to be opened either by the implosion caused by the pump, or by a cutting device (14) at the inlet (9, 26; 37) of the pump or pipe/hose (35), when rotating the container during its fitting into said pump inlet.
The apparatus of claim 5, characterized in that the cutting device (14) comprises at least one knife or at least one cutting tooth.
The apparatus of any one of claims 1 to 6, characterized in that the inlet end of the container (1, 20, 30) is closed by a removable sealing lid (2, 33) or a plastic foil or foil laminate diaphragm (19).
The apparatus of claim 7, characterized in that the sealing lid (2, 33) comprises a pierceable area (18) or a removable, plug-like closure member.
The apparatus of any one of claims 1 to 8, characterized in that the container (1, 20, 30) comprises a piston (4, 31) following the chemical contents (15) down as they are drawn into the pump (10).
The apparatus of claim 9, characterized in that the piston (4, 31) is a sliding fit within the container.
The apparatus of claim 9 or 10, characterized in that the skirt (5, 29) of the piston (4, 31) comprises a sealing lip (16A, 16B) at least on one of its ends.
The apparatus of any one of claims 9 to 11, characterized in that the piston (4, 31) has, at its surface facing the outlet, a protuding dome-like shape (6, 32) which fits into the contour of the reduced diameter outlet end (7) of the container (1, 20, 30).
The apparatus of any one of claims 1 to 12, characterized in that the cylindrical wall (13A, 23) of the container (1, 20, 30) is made of translucent or transparent plastics material and comprises a graduated scale (27).
The apparatus of any one of claims 1 to 13, characterized in that the the pump inlet (9, 26) or the pipe/hose (35) inlet (37) comprises a circular vent channel (13) with a vent hole (13A) and a valve (17), said vent channel being arranged between the fitting section (11B) of container outlet and pump inlet and the sealing means (11) at the interface (80, 81, 82).
The apparatus of any one of claims 1 to 14, in particular comprising a large container, characterized in that the container (30) is removably connected via a pipe/hose (35) to the pump inlet (9), the connecting means (41, 42; 41A, 42A) being either between the outlet end of the container and the pipe/hose (35) being fixed to the pump inlet (9), or between the end of the pipe/hose (35) being fixed to the outlet end of the container and the pump inlet, or between the pipe/hose and the outlet end of the container and the pump inlet.
The apparatus of claim 15, characterized in that the hose (35) is connected to at least one coupling piece (38, 38A) having ribs (39) and a ring (40) for retaining said hose (35), said coupling piece (38, 38A) further comprising one part of the connecting means (41, 41A), and, if need be, the cutting device (14).
The apparatus of any one of claims 1 to 16, in particular comprising a large container, characterized in that the sealing lid (32) comprises an inlet (34) for low pressure air application to the back of the piston (31) for overcoming frictional losses.
The apparatus of any one of claims 1 to 13, characterized in that a collecting dish (43) is provided under the vent hole (13A) of the vent channel (13).