Device and method for conveying viscous material

Abstract

An apparatus for conveying viscous material from a drum-like container with a container bottom and a circumferential container wall extending from the container bottom to a container upper side and being open at the container upper side has, for closing the container a follower plate having a material outlet attached to a conveyor pump. The follower plate has an annularly circumferential wiper ring that has a radially outwardly extending contacting part for contact against an inside face, turned toward the follower plate, of the container wall. The contacting part can be pressurized with a variable pressing force for pressing against the inside face (36) of the container wall. The follower plate is mounted by moans of at least one vertically extending retaining rod on a horizontally extending crosspiece mounted on or close to a first end on a lifting device for raising and lowering of the crosspiece. Its second end is free. This task is accomplished by an apparatus having the features according to one aspect of the invention as well as by a method having the features according to another aspect of the invention. Advantageous further developments of the invention are subject matter discussed below.

Claims

1. An apparatus for conveying viscous material from a drum-like container, which has a container bottom and a circumferential container wall extending from the container bottom to a container upper side and is open at the container upper side, with, for closing of the container, a follower plate having a material outlet attached to a conveyor pump, wherein the follower plate is provided with an annularly circumferential wiper ring, wherein the wiper ring has a radially outwardly extending contacting part for contact against an inside face, turned toward the follower plate, of the circumferential container wall, wherein the contacting part can be pressurized with a variable pressing force for pressing against the inside face of the circumferential container wall, wherein the follower plate is mounted by at least one vertically extending retaining rod on a horizontally extending crosspiece, which is mounted on or close to a first end on a lifting device for raising and lowering of the crosspiece, while its a second end of the crosspiece is free, and wherein the lifting device has at least one guide rod that is connected in fixed manner to the crosspiece and is linearly movable in a guide in vertical direction as well as a drive unit for raising and lowering of the crosspiece.

2. The apparatus according to claim 1, wherein each guide rod is linearly movable in a tubular guide and has a first guide element bearing on an inside face of the guide at or close to a lower end, while the guide has a positionally fixed second guide element bearing on an outside face of the guide rod at or close to an upper end.

3. The apparatus according to claim 1, wherein the lifting device has two guide rods extending parallel to one another and two guides extending parallel to one another.

4. The apparatus according to claim 1, wherein the lifting device is provided with a spindle drive for raising and lowering of the crosspiece.

5. The apparatus according to claim 1, wherein the contacting part can be retracted from the inside face of the circumferential container wall by reduction of the pressing force.

6. The apparatus according to claim 1, wherein the wiper ring is hollow and has an outer wall enclosing a cavity that is at least partly annularly circumferential and that can be filled with a pressurized medium.

7. The apparatus according to claim 6, wherein the outer wall is thicker in a region of the contacting part than in other regions of the outer wall.

8. The apparatus according to claim 6, comprising a device for injection of the pressurized medium into the cavity and for removal from the cavity.

9. The apparatus according to claim 8, wherein the contacting part, by pressurization of the cavity with two predetermined different pressures, is movable between a sealed position, in which the contacting part bears sealingly against the inside face of the circumferential container wall and a released position, in which a sealing effect with the inside face of the circumferential container wall is nullified.

10. The apparatus according to claim 1, wherein the follower plate is provided with at least one further wiper ring, which is structurally identical to and is disposed parallel to and at a spacing from the wiper ring.

11. The apparatus according to claim 1, wherein the conveyor pump has a conveyor cylinder and a conveyor piston that can be moved forward and back in the conveyor cylinder (44), and wherein a measuring device is provided for measurement of the speed of the conveyor piston.

12. The apparatus according to claim 11, wherein the measuring device has a distance-measuring unit for time-dependent measurement of a distance traveled by the conveyor piston.

13. The apparatus according to claim 12, wherein the conveyor piston is connected mechanically to the distance-measuring unit.

14. The apparatus according to claim 13, wherein the conveyor pump has a piston rod, which projects from the conveyor cylinder, is connected to the conveyor piston, and is connected rigidly by way of a connector to the distance-measuring unit.

15. The apparatus according to claim 12, wherein the distance-measuring unit is an absolute-value transmitter.

16. The apparatus according to claim 11, wherein the measuring device has a control unit for control of the conveying of the viscous material in dependence on a measured speed of the conveyor piston.

17. The apparatus according to claim 16, wherein a waste line leading to a waste container is branched off from a conveying line, attached to the conveyor pump, for the viscous material, and the conveying line can be blocked and the waste line released by the control unit.

18. A method for conveying of viscous material from a drum-like container, which has a container bottom and a circumferential container wall, extending from the container bottom to a container upper side, which is open at the container upper side, the method comprising: providing an apparatus comprising a follower plate having a material outlet attached to a conveyor pump, wherein the follower plate is provided with an annularly circumferential wiper ring, wherein the wiper ring has a radially outwardly extending contacting part for contact against an inside face, turned toward the follower plate, of the circumferential container wall, and wherein the contacting part can be pressurized with a variable pressing force for pressing against the inside face of the circumferential container wall, wherein the follower plate is mounted by at least one vertically extending retaining rod on a horizontally extending crosspiece, which is mounted on or close to a first end on a lifting device for raising and lowering of the crosspiece, while a second end of the crosspiece is free; moving the follower plate in the direction of the container bottom by following a descending material level in a manner resting on a surface of the material and, after emptying of the container, is moved moving the follower plate away from the container bottom; pressing the wiper ring, during the movement of the follower plate to the container bottom, sealingly with the contacting part of the wiper ring against the inside face of the circumferential container wall and, during the movement of the follower plate away from the container bottom, a sealing effect between the wiper ring and the circumferential container wall is nullified by reduction of the pressing force; wherein, using a control device, the emptied container is automatically transported away after removal of the follower plate; and wherein, using the control device, a container filled with the viscous material is positioned underneath the follower plate.

19. The method according to claim 18, wherein, for raising of the follower plate after emptying of the container, compressed air is injected into a region between the follower plate and the container bottom, before the sealing effect between the wiper ring and the circumferential container wall is nullified.

20. The method according to claim 18, wherein after replacement of the emptied container by the filled container, material is conveyed via a waste line into a waste container until the measured speed of the conveyor piston lies in a predetermined tolerance range around a predetermined target speed.

21. An apparatus for conveying viscous material from a drum-like container, which has a container bottom and a circumferential container wall extending from the container bottom to a container upper side and is open at the container upper side, with, for closing of the container, a follower plate having a material outlet attached to a conveyor pump, wherein the follower plate is provided with an annularly circumferential wiper ring, wherein the wiper ring has a radially outwardly extending contacting part for contact against an inside face, turned toward the follower plate, of the circumferential container wall, wherein the contacting part can be pressurized with a variable pressing force for pressing against the inside face of the circumferential container wall, wherein the follower plate is mounted by at least one vertically extending retaining rod on a horizontally extending crosspiece, which is mounted on or close to a first end on a lifting device for raising and lowering of the crosspiece, while a second end of the crosspiece is free, and wherein the apparatus comprises a transport device for transporting of the container in a direction perpendicular to a longitudinal extent of the crosspiece.

22. The apparatus according to claim 21, wherein the transport device has a roller track, on which the container is installed.

23. An apparatus for conveying viscous material from a drum-like container, which has a container bottom and a circumferential container wall extending from the container bottom to a container upper side and is open at the container upper side, with, for closing of the container, a follower plate having a material outlet attached to a conveyor pump, wherein the follower plate is provided with an annularly circumferential wiper ring, wherein the wiper ring has a radially outwardly extending contacting part for contact against an inside face, turned toward the follower plate, of the circumferential container wall, wherein the contacting part can be pressurized with a variable pressing force for pressing against the inside face of the circumferential container wall, wherein the follower plate is mounted by at least one vertically extending retaining rod on a horizontally extending crosspiece, which is mounted on or close to a first end on a lifting device for raising and lowering of the crosspiece, while a second end of the crosspiece is free, and wherein the apparatus comprises a housing that annularly surrounds the container and the follower plate and is provided with at least one door.

24. The apparatus according to claim 23, comprising a control device for automatic positioning of the container underneath the follower plate by the transport device, for automatic introduction of the follower plate into the container, for automatic removal of the follower plate (20) from the container after emptying the container and for automatic transportation away of the container by the transport device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained in more detail in the following on the basis of an exemplary embodiment illustrated schematically in the drawing, wherein:

(2) FIG. 1 shows a schematic sectional diagram of parts of an apparatus for the conveying of viscous material having a follower plate prior to its introduction into a container;

(3) FIGS. 2a, 2b show the diagram according to FIG. 1 with a follower plate introduced into the container at the beginning and at the end of the conveying process and

(4) FIGS. 3a, 3b show the diagram according to FIG. 1 with a follower plate present in the container in two different positions after the end of the conveying process

(5) FIGS. 4, 5 show an apparatus for the conveying of viscous material in front view and in overhead view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) The apparatus 10 illustrated schematically in the drawing is used for the conveying of viscous material such as adhesive, sealing compound or insulating compound from a drum-like container 12. This conveyor apparatus 10 is not illustrated in all details in FIGS. 1 to 3, but is reduced to the components essential for understanding of the sealing of the container 12. The container 12 has substantially a cylindrical shape with a container bottom 14 and a container wall 18 that extends upward from the container bottom 14 to a container upper side 16 and is annularly circumferential. The container 12 is open at the container upper side 16.

(7) The conveyor apparatus 10 has a follower plate 20, which for the conveying of the material is introduced into the container 12 and rests there on the material surface. The follower plate 20 may be moved up and down by means of a lifting device, not illustrated in FIGS. 1 to 3. In the middle, it has a dome 22, which extends upward from an underside 24 resting on the material and discharges into a material outlet 26. From the material outlet 26, the material is conveyed by means of a conveyor pump, likewise not illustrated in FIGS. 1 to 3, via a conveyor line to the point of use. In order to largely prevent the inclusion of air, it is also possible to construct the follower plate 20 without dome 22, i.e. with a plane underside, into which the material outlet 26 leads.

(8) The follower plate 20 is provided with an annularly circumferential wiper ring 28 of elastically expandable material, in the present case of rubber, which is formed in tubular manner, with an outer wall 32 enclosing an annular cavity 30. In its radially outwardly pointing and outwardly protruding region, the outer wall 32 is thickened with formation of a contacting part 34, which is designed for sealing contact against an inside face 36 of the container wall 18. When a pressurized medium is injected into the cavity 30, it is pressurized with compressed air, for example by means of an inflating and deflating device, not illustrated, the wiper ring 28 expands and the contacting part 34 is moved radially outward. Once the follower plate 20 has been introduced into the container 12, the contacting part is moved into a sealed position in which, as shown in FIGS. 2a, 2b, it is pressed by the force exerted by the compressed air in the cavity 30 against the inside face 36 and seals the container interior space 38 situated under the follower plate 20 from the surroundings.

(9) At the beginning of a conveying process, the follower plate 20 is situated in the position illustrated in FIG. 2a, in which its underside 24 rests on the surface of the material in the filled container 12. The contacting part 34 is situated in its sealed position, so that the wiper ring 28 seals the container interior space 38 from the surroundings. If material is being conveyed out of the container 12, the material level descends and the follower plate 20 is moved downward in the container 12 by means of the lifting device in a manner following the material level, wherein the contacting part 34 slides over the inside face 36 with overcoming of a frictional force and wipes off material adhering to this. Once the container has been completely emptied, the follower plate 20 is situated on the container bottom 14, as illustrated in FIG. 2b, wherein a thin material film possibly still remains between the follower plate 20 and the container bottom 14. After the emptying of the container 12, compressed air is injected into the dome 22, so that the follower plate 20 is raised from the container bottom 14. Simultaneously with the injection of compressed air into the dome 22, or a short time later, the force pressing the contacting part 34 against the inside face 36 is removed by release of compressed air from the cavity 30, so that the contacting part 34 is retracted from the inside face 36. The contacting part 34 is then situated in a released position, in which the sealing effect between the container interior space 38 and the surroundings is nullified. By means of the lifting device, the follower plate 20 is then lifted out of the container 12, until it is situated once again in the position illustrated in FIG. 1. The empty container 12 may then be replaced by a new, full container and the conveying process may begin anew.

(10) At the material outlet 26 of the follower plate 20, a conveyor pump 40 connected in fixed manner to the follower plate 20 is attached in order to convey material from the container 12 via the material outlet 26 into a conveying line 42 leading to a processing station. The conveyor pump 40 has a conveyor cylinder 44 mounted in fixed manner on the follower plate 20 as well as a conveyor piston, not illustrated in the drawing, which can be moved forward and back in the conveyor cylinder 44, and the linear movement of which in the conveyor cylinder 44 sucks material through the material outlet 26 into the conveyor cylinder 44 and forces the material out of the conveyor cylinder 44 into the conveying line 42.

(11) Since, by virtue of the variable diameter of the wiper ring 28, the follower plate 20 may be introduced almost contactlessly and without force exertion into the container 12 during a container replacement, a lifting device 50, on which a horizontally oriented crosspiece 52 in the form of a metal plate is mounted with its first end 54, while its second end 56 is free, is provided in the conveyor apparatus 10 according to the invention. From the crosspiece 52, two retaining rods 58, which carry the follower plate 20, extend vertically downward. The lifting device 50 is provided with a spindle drive, not shown in more detail, driven by means of an electric motor, for raising and lowering of the crosspiece 52.

(12) The conveyor apparatus 10 is additionally provided with a transport device 80, which has a roller track 82, with which the container 12 can be transported in a direction perpendicular to the longitudinal extent of the crosspiece 52. In this way, emptied containers 12 may be transported away from the follower plate 20 and full containers 12 may be transported underneath the follower plate 20. In addition, a housing 84 is provided, which annularly surrounds the container 12 and the follower plate 20 during the introduction of the follower plate 20 into the container 12 as well as during the conveying of the material. The housing 84 is provided with two transparent sliding doors 86, 88, which are disposed one above the other and respectively annularly surround an interior space, and which annularly surround the container 12, the follower plate 20 and the conveyor pump 40 during operation for minimization of the danger of injury to operator control personnel. In order that the conveyor pump 40 may be accessed, the upper sliding door 86 can be displaced downward, whereas the lower sliding door 88 can be displaced upward, to permit a container replacement. In addition, a control device is provided, with which a filled container 12 is positioned completely automatically underneath the follower plate 20 by means of feed movement on the roller track 82, with which the follower plate 20 is automatically introduced into the container 12, with which the follower plate 20, after the emptying of the container 12, is automatically removed from this, and with which the emptied container 12 is automatically transported away by means of the transport device 80. A sensor 98 recognizes the correct positioning of the container 12 underneath the follower plate 20.

(13) The conveyor apparatus 10 additionally has a measuring device 90, with which the speed of the conveyor piston during the delivery stroke may be measured. The measuring device 90 has a distance-measuring unit in the form of an absolute-value transmitter 92, the housing of which is mounted on the lifting device 50. A piston rod 94 connected in fixed manner to the conveyor piston is guided upwardly out of the conveyor cylinder 44 and by means of connecting rods 96 is connected rigidly to a movable element of the absolute-value transmitter 92. The distance-measuring device 90 additionally has a control unit, not illustrated in more detail, which controls the conveying of the viscous material in dependence on the measured speed of the conveyor piston. The control unit recognizes when the measured speed of the conveyor piston lies outside a tolerance range by a predesignated target speed, which suggests that the consistency of the material being conveyed has changed so much that its suitability is in question. In this case, the control unit operates a valve 100, so that the material being conveyed is conveyed not to the processing station but instead into a waste line 102, which is branched off from the conveying line 42 and leads to a waste container 104. If the control unit recognizes that the speed of the conveyor piston again lies within the tolerance range, it operates the valve 100 yet again and the viscous material is again conveyed via the conveying line 42 to the processing station. The measuring device 90 is intended in particular to prevent material permeated with air bubbles from being conveyed. It can be used in particular when the follower plate 20 has been introduced into a full container 12, in order to convey material in an automatic process into the waste container 104 until this no longer includes any air bubbles. However, it may also be used during the conveying process and detect the air bubbles present in the material in order to convey the material permeated with air bubbles into the waste container 104 instead of to the processing station. In FIG. 5, the illustration of the measuring device 90, of the valve 100, of the waste line 102 and of the waste container 104 has been omitted for the sake of clarity.

(14) In summary, the following is to be stated: The invention relates to an apparatus 10 for the conveying of viscous material from a drum-like container 12, which has a container bottom 14 and a circumferential container wall 18, extending from the container bottom 14 to a container upper side 16 and is open at the container upper side 16, with, for closing of the container 12, a follower plate 20 having a material outlet 26 attached to a conveyor pump 40, wherein the follower plate 20 is provided with an annularly circumferential wiper ring 28, wherein the wiper ring 28 has a radially outwardly extending contacting part 34 for contact against an inside face 36, turned toward the follower plate 20, of the container wall 18, and wherein the contacting part 34 can be pressurized with a variable pressing force for pressing against the inside face 36 of the container wall 18. According to the invention, it is provided that the follower plate 20 is mounted by means of at least one vertically extending retaining rod 58 on a horizontally extending crosspiece 52, which is mounted on or close to a first end 54 on a lifting device 50 for raising and lowering of the crosspiece 52, while its second end 56 is free.