Container-handling apparatus

Abstract

A transporter has stars arranged in series such that a container is transferred at a transfer point that is common to two successive stars. Some of the stars rotate about a fixed axis whereas other stars rotate about an axis that moves relative to the fixed axis.

Claims

1. An apparatus for handling containers selected from the group consisting of bottles and preforms, said apparatus comprising a container-handling machine and a transporter upstream of said container-handling machine, said container-handling machine being selected from the group consisting of a blow-molding machine, a labeling machine, a cleaning machine, a filling machine, and a packing machine, said transporter comprising stars arranged in series, each of said stars having container holders along a circumference thereof for gripping said containers, wherein said stars are arranged such that a container is transferred at a transfer point that is common to two successive stars, wherein each of said stars rotates about an axis, wherein said stars comprise fixed stars and movable stars, wherein said movable stars rotate about movable axes and said fixed stars rotate about fixed axes, and wherein said movable axes are movable in a controlled manner relative to said fixed axes.

2. The apparatus of claim 1, wherein at least one of said movable axes revolves around a fixed axis.

3. The apparatus of claim 1, wherein at least one of said movable axes revolves around a point in a horizontal plane.

4. The apparatus of claim 1, wherein at least one of said movable axes moves linearly along a horizontal plane.

5. The apparatus of claim 1, further comprising a controller that controls movement of said movable axes so as to maintain said transfer points between adjacent stars during such movement, thereby permitting container transfer to be unimpeded by said movement.

6. The apparatus of claim 1, further comprising a controller that receives information indicative of container throughput and causes movement of said movable axes in response to said information.

7. The apparatus of claim 1, wherein said movable stars comprise first, second, and third stars, said second star being between said first and third stars, wherein axes of said first and third stars move by revolving around corresponding points and an axis of said second star moves linearly.

8. An apparatus for handling containers, said apparatus comprising a transporter upstream of a container-handling machine, said transporter comprising stars arranged in series, each of said stars having container holders along a circumference thereof for gripping containers, wherein said stars are arranged such that a container is transferred at a transfer point that is common to two successive stars, wherein each of said stars rotates about an axis, wherein said stars comprise fixed stars and movable stars, wherein said movable stars rotate about movable axes and said fixed stars rotate about fixed axes, wherein said movable axes are movable in a controlled manner relative to said fixed axes, and wherein said movable stars comprise first, second, and third stars, said second star being between said first and third stars, wherein axes of said first and third stars move by revolving around corresponding points and an axis of said second star moves linearly.

9. A method comprising compensating for a mismatch between container input and container output in a transporter that is upstream of a container-handling machine selected from the group consisting of a blow-molding machine, a labeling machine, a cleaning machine, a filling machine, and a packing machine, said transporter comprising stars arranged in series, each of said stars having container holders along a circumference thereof for gripping containers at necks thereof, wherein said stars are arranged such that a container selected from the group consisting of bottles or preforms is transferred at a transfer point that is common to two successive stars, wherein each of said stars rotates about an axis, wherein said stars comprise fixed stars and movable stars, wherein said movable stars rotate about movable axes and said fixed stars rotate about fixed axes, and wherein said movable axes are movable in a controlled manner relative to said fixed axes, wherein compensating for said mismatch comprises receiving information indicative of container throughput along said transport stretch and, in response to said information, changing a length of said transport stretch, wherein changing said length comprises causing said movable stars to move relative to said fixed stars.

10. The method of claim 9, wherein said movable stars are between said fixed stars.

11. The method of claim 9, wherein causing said movable stars to move comprises causing three movable stars to move, wherein causing said three movable stars to move comprises causing a first movable star to move along a circular arc centered at an axis of a first fixed star and causing a second movable star to move along a circular arc centered at an axis of a second fixed star.

12. The method of claim 9, wherein causing said movable stars to move comprises causing said movable stars to move in a manner that maintains transfer points between said movable stars and said fixed stars.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The invention is described hereinafter by means of an exemplary embodiment. The Figures show:

(2) FIG. 1 shows a view from above onto the container-handling apparatus with shortened transport stretch,

(3) FIG. 2 shows the apparatus of FIG. 1 with an extended transport stretch,

(4) FIG. 3 shows a sketch of the mathematical calculation of the transport stretches from the accumulation of the circumferential stretches of the containers on the individual stars,

(5) FIG. 4 shows a variable transport stretch on a group of five stars arranged behind one another, wherein the first and last stars are fixed, and

(6) FIGS. 5 to 15 show positions of axes-of-rotation in a group of seven stars when reducing transport stretch to lower buffer capacity.

DETAILED DESCRIPTION

(7) FIG. 1 shows a container-handling apparatus 10 having a container delivery feed 12 and a transporter 14 comprising star wheels, which will be referred to herein as “stars” 20a-20e. The stars 20a-20e transport containers 23 between the container delivery feed 12 and a container-handling machine 16. Each star 20a-20e rotates about its corresponding axis 15a-15e. Each star 20a-20e also has container holders evenly spread along its circumference.

(8) The transfer from a first star 20a-20d to a second star 20b-20e that follows takes place at a transfer point 17a-17d that is common to both stars 20a-20e. While on a particular star 20a-20e, a container 23 traverses a “circumferential stretch.” This circumferential stretch is given by the product of the star's radius and the angle traversed by the container, in radians. The total distance travelled by a container 23, referred to herein as the “transfer stretch 22,” is formed by the accumulated circumferential stretches of the containers 23 on each of the stars 22a-22e between first and last transfer points 17a-17d.

(9) A transporter 14 comprises fixed stars 20a, 20e and movable stars 20b-20d. The fixed stars 20a, 20e have fixed axes 15a, 15e. The movable stars 20b-20d have movable axes 15b-15d. These movable axes 15b-15d either move along a plane, either by moving linearly or along an arc of a circle. In FIG. 1, there are first and second fixed stars 20a, 20e and first, second, and third movable stars 20b-20d.

(10) As a result of having movable stars 20b-20d, it is possible to control the locations of the transfer points 17a-17d. This makes it possible to control the circumferential stretch 22 of the containers 23 on the stars 20a-20e.

(11) A controller 18 controls such movement. To provide the controller 18 with the information it needs, a data connection 13 connects the controller 18 to a detector 24. In some embodiments, the data connection 13 is wireless and in others it is wired.

(12) As a result of the data connection 13, the controller 18 learns whether containers 23 are entering the transporter 14 at a rate that differs from the rate at which they are leaving the transporter 14. This can be achieved by measuring the delivery feed rate in the region of the feed 12 and using it to calculate the container throughput or by obtaining measurements of both the delivery feed rate and the rate at which containers exit the transporter 14.

(13) Using the above information, the controller 18 moves the movable stars 20b-20d to lengthen or shorten the transfer stretch 22. This permits the creation of a buffer zone using the circumferential stretches of the containers 23 on the stars 20a-20e. It also permits the dynamic variation of that buffer zone as circumstances require. The ability to dynamically vary the buffer zone provides a way to compensate for short-term differences between the container delivery rate calculated by the detector 24 and the container throughput indicated by the container-handling machine 16.

(14) Upon detecting the possibility of a container backup in the transporter 14, the controller 18 causes a drive 26 to enlarge the buffer zone by reconfiguring the transporter 14 from the state shown in FIG. 1 to the state shown in FIG. 2. In particular, the drive 26 moves the first and third movable stars 20b, 20d along a circular arc shown by the arrows in FIG. 1. This moves their corresponding axes 15b, 15d along arcs of two circles as they revolve part-way around the axes 15a, 15e of the corresponding first and second fixed stars 20a, 20d. Meanwhile, the drive 26 also moves the second movable star 20c linearly to maintain all transfer points 17b, 17c with the first and third movable stars 20b, 20d.

(15) In the configuration shown in FIG. 2, the entire transport stretch 22, i.e. the accumulated circumferential stretch on all three fixed stars 20b, 20c, 20d, is substantially greater than that shown in FIG. 1. This has the effect of enlarging the transporter's buffer zone, thus permitting it to catch up with a short-term capacity bottleneck in the container-handling machine 16. Once the container-handling machine can again run at full capacity, the drive 26 reduces the buffer's size by reconfiguring the transporter 14 into the original state, which is shown in FIG. 1.

(16) FIG. 3 shows a similar arrangement as in FIGS. 1 and 2, in which parts that are identical or have the same function are provided with identical reference numbers. The transporter 14 in this case has two fixed stars 20a, 20e and two movable stars 20b, 20c between the fixed stars 20a, 20e.

(17) In this case, the containers 23 run from the container delivery feed 12 onto the first fixed star 20a. From there they traverse a first angle α1 to reach a first transfer point 17a onto the first movable star 20b. The containers 23 then traverse a second angle α2 to reach a second transfer point 17b, where they are transferred to the second movable star 20c. The containers then traverse a third angle α3 to reach a third transfer point 17d, where they are transferred onto the second fixed star 20e. The containers then traverse a fourth angle α4 as far as a removal point.

(18) The first movable star 20b has its axis 15b mounted so as to be move along a circle with the radius ra as it revolves around the first fixed-star's axis 15a. In this way, the first movable star 20b maintains the first transfer point 17a. The same activity arises with the second movable star 20c and the second fixed star 20e. As a result, there is no interruption in container handling while the buffer is being dynamically changed. A suitable drive 26 is implemented by having two rotation arms linked to the axes 15b, 15c of the movable stars 20b, 20c.

(19) FIG. 4 in turn shows a transporter 14 that is similar to that shown in FIG. 1 but with the second movable star 20c being much larger than the first and third movable stars 20b, 20d. The second movable star 20c is moved linearly along a direction perpendicular to a line that connects the axes 15a, 15e of the fixed stars 20a, 20e. The axes of the movable stars 20b, 20d revolve around the fixed axes 15a, 15e as shown in FIG. 3.

(20) It is advantageous, but not essential, for the transfer points 17a-17d to be maintained during the movement of the stars 20b-20d. In principle it would also be possible for contact between the stars 20b-20d to be released during reconfiguration of the transporter 14. The stars 20a-20d would then be brought back into contact to reform the transfer points 17a-17d after configuration has been completed. However, this would mean that reconfiguration could not be carried out while containers 23 are being handled.

(21) FIGS. 5 to 15 show, by analogy with FIGS. 1 to 4, a transporter 14 with seven stars 30a-30g, each of which rotates about a corresponding axis 32a-32g. Of these seven stars 30a-30g, there are three movable stars 30c, 30d, 30e with corresponding three movable axes 32c, 32d, 32e. The configuration sequence shown in FIGS. 5 to 13 shows the three movable stars 30c, 30d, 30e moving in a way that shortens the transport stretch 22, which reaches its minimum length in FIG. 15.

(22) In FIG. 5, the seven stars 30a-30g are arranged so that the circumferential stretch on each star 30a-30g is quite long. As a result, the transport stretch 22 is also long. The three movable stars 30c, 30d, 30e are held on axes that revolve around the fixed axes 32b, 32f of adjacent stars 30b, 30f.

(23) As can be seen at the end of the movement path in FIG. 13, the transport stretch 22 in the end position, after the adjustment of the three movable stars 30c, 30d, 30e, is substantially shorter over the entire group of the seven stars 30a-30g than at the beginning in FIG. 5. In this way, therefore, a quantity on the buffer stretch is reduced, for example, if, in the context of a short period of asynchronous operation during which the handling capacity of the container-handling machine 16 is greater than the delivery feed rate from the container deliver feed device 12. To increase the buffer's size, the configuration is run in reverse from FIG. 15 to FIG. 5.

(24) In some embodiments, the movable axes 32c, 32d, 32e, instead of being mechanically linked, are moved by a linear drive.

(25) In other embodiments, one or more fixed tracks or guide carves positively guide the motion of the movable stars 20b-20d. Other embodiments include those in which additional or alternative drive means are provided, which are not fixed in or at one of the stars, by means of which the rotational and/or travel movement of these movable stars 20b-20d is achieved.