Container Handling System, Container Carrier, and Method for Filling Containers

Abstract

A container carrier connects to a filling machine with a gripper on one end that suspends a container during transport thereof along a transport direction. A deformation sensor arranged on a surface of the carrier detects the carrier's deformation when, as a container is filled, the weight of filling product deforms the carrier.

Claims

1-18. (canceled)

19. An apparatus comprising a container carrier and a deformation-sensor system, wherein said container carrier connects to a filling machine at which said container carrier is held, a gripper that suspends a container during transport thereof along a transport direction, and a surface, and wherein said deformation-sensor system comprises a deformation sensor that is arranged on said surface to detect deformation of said container carrier caused by an increase in weight of said container as filling product enters said container during filling thereof.

20. The apparatus of claim 18, wherein said deformation sensor comprises a strain gauge.

21. The apparatus of claim 18, wherein said deformation-sensor system comprises a plurality of deformation sensors at said container carrier.

22. The apparatus of claim 18, wherein said deformation-sensor system comprises a first deformation sensor and a second deformation sensor, wherein said first deformation sensor is on an upper side of said container carrier, and wherein said second deformation sensor is on an underside of said container carrier.

23. The apparatus of claim 18, wherein said deformation-sensor system comprises at least four deformation sensors, all of which are on corresponding surfaces of said container carrier.

24. The apparatus of claim 18, wherein said deformation-sensor system comprises plural deformation sensors, each of which defines a resistance in a bridge circuit.

25. The apparatus of claim 18, wherein said deformation-sensor system comprises plural deformation sensors, each of which comprises a contact point, said apparatus further comprising cables that are soldered to said contact points.

26. The apparatus of claim 18, wherein said deformation-sensor system comprises plural deformation sensors that are connected in a bridge circuit, wherein said apparatus further comprises a plug and cables that extend between said deformation sensors and said plug, that is arranged at an end of said cable that faces away from said deformation sensors.

27. The apparatus of claim 18, wherein said deformation sensor is sealed to prevent contact between said deformation sensor and water.

28. The apparatus of claim 18, wherein said container carrier transports said container along a circular track that defines a circle and wherein said deformation sensor is disposed within said circle.

29. The apparatus of claim 18, wherein said container carrier is a unitary plastic structure made of a plastic that has a reproducible module of elasticity.

30. The apparatus of claim 18, wherein said container carrier is a multi-part structure that is made of a steel that has a reproducible module of elasticity.

31. The apparatus of claim 18, wherein said deformation sensor is disposed on a surface of said container carrier between proximal and distal ends thereof.

32. The apparatus of claim 18, further comprising a container-handling machine that comprises a rotor that comprises filling elements, wherein said container carrier is one of a plurality of container carriers on said rotor.

33. A method comprising suspending a container from a gripper of a container carrier, transporting said container along a transport direction, while transporting said container, filling said container, using a deformation-sensor system, measuring deformation of said container carrier as a result of an increase in said container's weight as filing product enters said container during filling thereof, determining that a predetermined weight has been reached, and halting filling of said container, wherein said deformation-sensor system comprises a deformation sensor that is arranged on a surface of said container carrier.

34. The method of claim 32, further comprising converting said deformation into a weight, wherein converting said deformation into a weight comprises using a look-up table to determine a weight that corresponds to a particular deformation.

35. The method of claim 32, further comprising converting said deformation into a weight, wherein converting said deformation into a weight comprises using a formula to determine a weight that corresponds to a particular deformation.

36. The method of claim 32, wherein said deformation-sensor system comprises plural deformation sensors, each of which is arranged on a corresponding surface of said container carrier and wherein measuring said deformation comprises evaluating said deformation based on measurements from all of said deformation sensors.

37. The method of claim 32, further comprising measuring a kinematic property of said container and using said kinematic property and measurements from said deformation-sensor system to determine when to halt filling of said container.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The invention is described in greater detail hereinafter on the basis of the Figures in respect of exemplary embodiments. These show, by way of example:

[0035] FIG. 1 shows a container-handling system;

[0036] FIG. 2a shows a side view of a container carrier from the system of FIG. 1 as it carries an unfilled container;

[0037] FIG. 2b shows the container carrier of FIG. 2a as it carries a partially-filled container;

[0038] FIG. 3 shows a bridge circuit; and

[0039] FIG. 4 shows a perspective view of an alternative embodiment of a container carrier from the system of FIG. 1.

[0040] Identical reference numbers are used in the figures for elements which are the same or have the same effect. Furthermore, for the purpose of easier overview, only reference numbers are represented in the individual figures which are required for the description of the respective figure.

DETAILED DESCRIPTION

[0041] FIG. 1 shows a container-handling system 1 that includes a filling machine. The container-handling system 1 includes a rotor 5 that rotates about a vertical axis “A”. Along the circumference of the rotor 5 are container carriers 4. A container carrier 4 receives a container 2 at an inlet star 3 and transport containers 2 in a transport direction “T” along a circular arc as the rotor 5 rotates. The container carrier 4 then discharges the container 2 at an outlet star 10, which takes the container for further processing. The container-handling system 1 also includes filling elements 6. Each filling element 6 connects to a circular channel 8 by way of a valve 7.

[0042] In operation, when the container carrier 4 positions the container 2 at a filling element 6, the valve 7 opens, thus allowing filling material that is stored in the channel 8 to fill the container 2. The filling elements 6 shown in black are those in which the valve 7 is open so that the container 2 is being filled. The remaining filling elements 6 are those in which the valve 7 is closed.

[0043] Referring to FIG. 2a, a carrier 4 is a cantilevered structure that extends radially outward from the rotor 5 from a proximal end that mounts to the rotor 5 to a distal end, from which a gripper suspends the container 2. The container 2 is empty in FIG. 2a but partially filled in FIG. 2b.

[0044] In FIG. 2a, the container 2 is empty. Hence, any deformation of carrier 4 arises only from the container's empty weight. As the container 2 fills, the container's growing weight deforms the carrier 4, as shown in FIG. 2b. This results in the carrier's deformation, which is shown in exaggerated form in FIG. 2b for clarity of exposition.

[0045] Deformation sensors 9 on the carrier's surface 11 measure the carrier's deformation. Since the extent of deformation depends on the weight of the filling material in the container 2, it is possible to infer the amount of product in the container 2 by observing the extent of deformation. In some embodiments, the deformation sensors 9 are strain gauges on upper and lower sides 12, 13 of the carrier 4. However, other types of deformations sensors 9 can be used.

[0046] In some cases, the container 2 is improperly taken up in a slightly asymmetric manner so that it is slightly offset at the container carrier 4. To avoid measurement inaccuracies, it is useful for the deformation sensors 9 to be arranged on either side of a plane of symmetry at the carrier 4. Measurements from different sides of the plane of symmetry can then be used to estimate the container's weight.

[0047] The filling valve's state is controlled based on the sensed weight. In some embodiments, the valve 7 is closed upon reaching a predetermined weight. In other embodiments, the rate of filling is slowed upon reaching a first predetermined weight and stopped upon reaching a second predetermined weight. This permits the weight of filling material to be controlled more accurately.

[0048] The valve 7 is made to stop filling the container when the deformation sensor's output reaches a predetermined measured value. The predetermined measured value is obtained either empirically, by measurement, or by calculation. A suitable calculation method is one that relies on the finite-element method to establish a correspondence between the container's weight and the extent of deformation. Some embodiments rely on a look-up table or formula to determine weight based on deflection. In some embodiments, finite-element calculations to infer weight from deflection are carried out in real time using a fast processor.

[0049] Each deformation sensor 9 has a contact point 14 to which a cable 15 connects. This permits a signal from the deformation sensor 9 to be evaluated remotely from the carrier 4.

[0050] The illustrated embodiment shows upper and lower deformation sensors 9 on the upper side 12 and lower side 13 of the carrier 4, respectively. The upper and lower deformation sensors 9 experience extension and compression, respectively.

[0051] In principle, only one deformation sensor 9 is required. However, having two deformation sensors 9 permits cancellation of errors due to sources that affect both sensors 9 equally. For example, if only one deformation sensor 9 were present, a temperature-induced change in sensor performance could not be accounted for. In contrast, by taking a difference between two deformation sensors 9, any such temperature-induced errors could be cancelled.

[0052] A preferred embodiment features four deformation sensors 9, with two on the upper side 12 and two on the lower side 13. The deformation sensors 9 are arranged in pairs on either side of a plane of symmetry of the carrier 4. This configuration permits cancellation of error due to both temperature changes and error that arises when the container 2 is not held symmetrically at the carrier 4.

[0053] In those embodiments in which the deformation sensors 9 are strain gauges, electrical resistance of each deformation sensor 9 changes as a result of compression or extension thereof. In such cases, it is useful to arrange the sensors 9 to form a bridge circuit as shown in FIG. 3. In the illustrated bridge circuit, R1 and R4 represent electrical resistances of deformation sensors 9 on the upper surface 12 on opposite sides of the plane of symmetry. The remaining two resistances, R3 and R4, represent electrical resistances of deformation sensors 9 on the lower side 13 on opposite sides of the plane of symmetry. A voltage U applied as shown results in a voltage drop across a measurement resistor Rm. This voltage drop indicates an extent of the carrier's deformation.

[0054] In an alternative embodiment, shown in FIG. 4, a container carrier 4 takes the form of a passive clip that elastically deforms. The container carrier 4 includes a distal holding end 21 that is elastically deformed to receive a container 2. The restoring force that results from this deformation tends to fix the container 2 in a gripping position.

[0055] The clip features two cavities 18 having horizontal surfaces 11. In the illustrated embodiment, each cavity 18 is a window or cut-out opening of a lateral element 4.1, 4.2 of the container carrier 4. Each cavity 18 accommodates two deformation sensors 18 on the two horizontal surfaces 11 thereof. As a result, there are four deformation sensors 9. However, other embodiments include additional deformation sensors 9.

[0056] At its proximal end, the container carrier 4 has an alignment opening 20 that promotes correctly positioning the container carrier 4 on a container-handling system 1. When the container carrier 4 is in its correct position, the distal gripping end 21 is suitably located to take up a container 2.

[0057] Cables 15 extend from contact points 14 of the deformation sensors 9 proximally towards a plug 19 that receives the cables 15. These provide electrical communication with the deformation sensors 9. The use of a plug 19 makes it possible to rapidly connect the deformation sensors 9 to a corresponding socket on the container-handling system 1. This makes it possible to swiftly replace the container carrier 4 as a modular unit should it become worn or broken.

[0058] Preferably, the plug 19 is water-tight to avoid having water due to condensation or spray influence the measurements. In some embodiments, the deformation sensors 9 are covered with a protective material or the cavities 18 are filled with a casting material to protect the deformation sensors 9 from being in contact with stray water.

[0059] The invention has been described heretofore on the basis of exemplary embodiments, and in this context the container carriers have been represented only schematically. It is understood that more complex grippers, in particular also actively controllable grippers with gripper arms mounted on bearings and capable of pivoting, can be provided for in an analogous manner.

[0060] It is further understood that a large number of modifications or derivations are possible without thereby departing from the scope of protection of the invention as defined by the claims.