US20070271882A1

US20070271882A1 - System for ordering, conveying, and depositing small objects

Info

Publication number: US20070271882A1
Application number: US11/803,145
Authority: US
Inventors: Harald Litke; Wolfgang Krahl; Markus Habdank; Martin Seiffert
Original assignee: Uhlmann Pac Systeme GmbH and Co KG
Current assignee: Uhlmann Pac Systeme GmbH and Co KG
Priority date: 2006-05-11
Filing date: 2007-05-11
Publication date: 2007-11-29
Also published as: EP1854723A3; ATE433913T1; EP1854723B1; EP1854723A2; DE102006022260A1; DE502007000876D1; DE102006022260B4

Abstract

An apparatus for packaging small identical objects in respective pockets of a package strip where the pockets are in a succession of identical arrays has a conveyor extending and displaceable from an upstream loading end to a downstream transfer end and having a plurality of sections each formed with an array of pockets dimensioned to hold a respective one of the objects. The array of each section corresponds to at least two of the arrays of the package strip interleaved with each other so that each section can hold a number of the objects equal to at least twice what one of the arrays of the package strip can hold. The objects are fed to the conveyer at the upstream end ordered such that at the transfer station there is one of the objects in each of the pockets.

Description

FIELD OF THE INVENTION

The present invention relates to a system for packaging small objects. More particularly this invention concerns a system for separating small objects into an orderly array and depositing them into respective blisters or pockets of a packaging strip.

BACKGROUND OF THE INVENTION

Small objects such as pills, capsules, and tablets are typically produced in bulk but packaged by placing them each in a respective pocket or blister of a plastic packaging strip. Thus the process entails the steps of separating the pills from each other, positioning them in an orderly array, and then transferring them from this array to the respective pockets of the packaging strip.
The sorting and arraying step is relatively easy. The objects are deposited on a slightly inclined and relatively broad feed plate that is vibrated such that the objects orient themselves in a single layer. The lower outlet end of the vibrating feed plate deposits them gently on a slowly moving conveyor formed with an array of upwardly open pockets typically arrayed identically to the blisters pockets of the packaging strip to be loaded. The pockets of this conveyor are dimensioned such that they can each just hold a single one of the objects, and the conveyor is vibrated also so that the objects work their way into the pockets, filling them all. A scraper oriented somewhat downstream along the path of the conveyor pushes the excess objects off the upper surface of the conveyor and recirculate them back to the upstream end of the process, so that downstream of the scraper the conveyor is transporting an exactly ordered array of the objects, one in each pocket.
At a loading station at the downstream end of the conveyor a transfer device comprising a multiplicity of suction grabs oriented identically to the conveyor pockets drops down on the conveyor, which can move slowly continuously or in steps, and picks out all the objects from a short length of the conveyor, then swings normally further downstream and deposits the picked-up objects into the pockets of the packaging foil, which typically is moving in steps transversely past the downstream end of the conveyor. Once a section of the conveyor has been emptied, it typically drops downward to recirculate back to the upstream conveyor end at the downstream end of the vibrating feed plate and get reloaded.
Thus in this system, which is basically described in German patent document 199 26 893 of D. Gertitschke, the conveyor is formed as a succession of hinged together plates each having an array of pockets identical to some multiple of the array of the package to be produced, and the transfer device has an identical number of grabs. Thus for example if a pill package is to be produced that holds six pills, each conveyor plate can hold 84 pills and the transfer device will have 84 grabs, so that a strip of packaging strip can be loaded with each cycle for subsequent division into 14 packages each holding six pills.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide an improved system for ordering, conveying, and depositing small objects.
Another object is the provision of such an improved system for ordering, conveying, and depositing small objects that overcomes the above-given disadvantages, in particular that can work faster, that is package more of the small objects in less time.

SUMMARY OF THE INVENTION

An apparatus for packaging small identical objects in respective pockets of a package strip where the pockets are in a succession of identical arrays has according to the invention a conveyor extending and displaceable from an upstream loading end to a downstream transfer end and having a plurality of sections each formed with an array of pockets dimensioned to hold a respective one of the objects. The array of each section corresponds to at least two of the arrays of the package strip interleaved with each other so that each section can hold a number of the objects equal to at least twice what one of the arrays of the package strip can hold. The objects are fed to the conveyer at the upstream end ordered such that at the transfer station there is one of the objects in each of the pockets and otherwise the conveyor is free of the objects. A transfer device at the transfer station has a plurality of grabs in a number and array equal to one of the arrays of pockets of the package strip. A controller relatively displaces the packaging strip, the conveyor, and the transfer device such that in a first half cycle the transfer device picks up all the objects from one of the interleaved arrays of pockets of the conveyor section at the transfer station and deposits the picked up objects into the packaging strip. Thereafter in a second half cycle the package strip is advanced by a length of one of its pocket arrays and the transfer device picks up all the objects from the other of the interleaved arrays of the same section in the transfer station and deposit the picked up objects into the packaging strip downstream of the previously deposited objects and the conveyor is advanced to bring another of the conveyor sections into the conveyor station.
The instant invention is based on the discovery that it is the loading of the conveyor, which has to be done perfectly since if one pocket is left empty the resultant package is a reject, that is the limiting factor on the operation speed of the system. Furthermore the conveyor has to be moved at a very slow pace to work properly and prevent any of the objects from popping out of its pocket. Thus according to the invention the conveyor sections each hold a number of objects equal to at least twice what each grab can pick up and handle at a given time, meaning that the grab can operate at basically double speed, which it is perfectly capable of doing without error, while the conveyor continues its steady careful and normally stepwise advance.
According to the invention the pockets of the arrays of the sections are arrayed in columns extending in a travel direction of the conveyor and rows extending transverse to the direction. Furthermore in a first half of the cycle the transfer device first picks up all the objects in every other row of the conveyor section and deposits them in a respective array of the package strip and then in a second half of the cycle picks up the objects in the remaining rows and deposits them in the next array of the package strip. Of course if each conveyor section array holds three or four times the number of objects as the strip arrays, the pickup device cycles back three or four times for each cycle. Furthermore the pickup device or the conveyor can shift transversely to the conveyor travel direction between succeeding part cycles for picking up of another interleaved array.
Furthermore in accordance with the invention between the first and second halves of the cycle the controller advances the conveyor in the direction by a distance equal to a spacing between immediately succeeding rows of the pockets in the conveyor, meaning that the arrays are interleaved in the conveyor travel direction. Alternately to pick up the objects the transfer device is moved at the start of each half cycle upstream to a position above the section of the conveyor in the transfer station, but at the start of the second half of the cycle the transfer device is moved back upstream by a distance shorter or longer by an amount equal to the spacing in the direction between succeeding rows of the pockets than the distance it is moved for the first half of the cycle. Thus the pickup location for the objects from the conveyor can be changed either by shifting the pickup position of the pickup device or the position of the conveyor.
It is useful when the array has pockets or cups arranged in columns. This provides in particular the possibility that sorting aids are embodied between the columns on the surface of the conveyor plate, that is, it facilitates adding the small objects to the pockets from which they can then be removed by the suction grippers for the transfer. In their simplest design, the sorting aids are formed by ridges that have a triangular cross-section and that have sides facing the pockets so that small objects conveyed from a supply container to the conveyor plate slide along the sides of the sorting aids, are arranged in columns, and can be shaken or brushed into the pockets.
In order to prevent damage to the small objects, it is worthwhile when the conveyor plate is provided with a friction-reducing coating, for instance polytetrafluoroethylene.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:
FIG. 1 perspective view of an inventive apparatus;
FIG. 2 is a detail view of the downstream end of the apparatus;
FIG. 3 is a detail view of a single conveyor plate; and
FIG. 4 is a top view showing a single conveyor plate and the adjacent package strip.

SPECIFIC DESCRIPTION

As seen in FIG. 1 an apparatus sorts, feeds, and arrays small objects to be packaged, such as tablets, coated tablets, pills, or the like, into the blisters 14 of a package strip 6 that form succeeding arrays each holding fourteen subarrays A or B each in turn with six of the blisters 14. This apparatus has a supply 1 downstream of which in a conveyor travel direction 10 is a conveyor formed of an endless loop of plates 4 each formed with an array of pockets 12. Each plate 4 as shown in FIG. 4 is formed with 168 pockets 12 so that, as described below, each plate can hold enough of the objects to fill all two succeeding arrays of subarrays A and B. To this end the pockets 12 of the plates 4 as oriented as shown in FIG. 12 in 28 columns extending in the direction D and spaced apart identically to the blisters 14 of the strip 16 and six rows spaced part in the direction by a distance equal to half the spacing of the pockets 14 in the same direction.
In the illustrated embodiment depicted in the drawing, the small objects are metered via vibrating troughs 2 and a slide 3 to the plurality of conveyor plates 4 that are moved via holders 5 in the direction 10 toward the package strip 6. During this transport process, the small objects are caused to move into the pockets 12 by shaking. The excess product is scraped off upstream of a transfer station 7 adjacent the package strip 6. Then the small objects are removed from the pockets 12 by means of a transfer device 8 and transferred into the blisters 14 of the package strip 6, the transfer device 8 itself having a plurality of suction grippers that are arranged in the same array as the blisters 4 in the package strip and the alternate rows of pockets 12 in the conveyor plates 4.
To increase the capacity in the inventive apparatus, the arrays A and B of the pockets 12 is embodied multiple times in the conveyor plate 4 (FIG. 4) with a minimum offset, determined by the size of the pockets 12, between two adjacent arrays A and B that are offset in the direction that is perpendicular to a transverse direction 11 of travel for the package strip 6. In order to be able to transfer with no problem from the pockets 12 into the blisters 14 of the package strip using the transfer device 8, despite the plurality of arrays A and B formed in one conveyor plate 4, there is either an incremental displacement of the conveyor plate 4 by the offset or the position of the suction grippers in the transfer device 8 is adapted using a corresponding incremental displacement of the suction grippers during positioning of the plate carrying the latter in the transfer device 8.
The plates have sorting ridges 13 (FIG. 3) on the surface on the conveyor plate 4 between the columns and of triangular cross-section with sides facing the pockets 12. The conveyor plate 4 is furthermore provided with coating that reduces friction, Teflon for instance being suitable for this. The conveyor plate 4 itself can be made of steel or even aluminum when reduced weight is needed.
In the case of a continuously running package strip 6, a plurality of cycles can be executed for the transfer device 8 from one conveyor plate 4 so that the need to move them is less frequent and more time is available for filling the other conveyor plates 4.

Claims

1. An apparatus for packaging small identical objects in respective pockets of a package strip where the pockets are in a succession of identical arrays, the apparatus comprising:

a conveyor extending and displaceable from an upstream loading end to a downstream transfer end and having a plurality of sections each formed with an array of pockets dimensioned to hold a respective one of the objects, the array of each section corresponding to at least two of the arrays of the package strip interleaved with each other, whereby each section can hold a number of the objects equal to at least twice what one of the arrays of the package strip can hold;

means for feeding the objects to the conveyer at the upstream end and ordering them such that at the transfer station there is one of the objects in each of the pockets and otherwise the conveyor is free of the objects;

a transfer device at the transfer station and having a plurality of grabs in a number and array equal to one of the arrays of pockets of the package strip; and

control means for relatively displacing the packaging strip, the conveyor, and the transfer device such that

in a first half cycle the transfer device picks up all the objects from one of the interleaved arrays of pockets of the conveyor section at the transfer station and deposits the picked up objects into the packaging strip,

thereafter in a second half cycle the package strip is advanced by a length of one of its pocket arrays and the transfer device picks up all the objects from the other of the interleaved arrays of the same section in the transfer station and deposit the picked up objects into the packaging strip downstream of the previously deposited objects, and the conveyor is advanced to bring another of the conveyor sections into the conveyor station.

2. The packaging apparatus defined in claim 1 wherein the pockets of the arrays of the sections are arrayed in columns extending in a travel direction of the conveyor and rows extending transverse to the direction.

3. The packaging apparatus defined in claim 2 wherein in the first half cycle the transfer device picks up all the objects in every other row of the conveyor section and deposits them in a respective array of the package strip and then in the second half cycle picks up the objects in the remaining rows and deposits them in the next array of the package strip.

4. The packaging apparatus defined in claim 2 wherein between the first and second halves of the cycle the control means advances the conveyor in the direction by a distance equal to a spacing between immediately succeeding rows of the pockets in the conveyor.

5. The packaging apparatus defined in claim 2 wherein to pick up the objects the transfer device is moved at the start of each half cycle upstream to a position above the section of the conveyor in the transfer station, but at the start of the second half of the cycle the transfer device is moved back upstream by a distance shorter or longer by an amount equal to the spacing in the direction between succeeding rows of the pockets than the distance it is moved for the first half of the cycle.

6. The packaging apparatus defined in claim 2 wherein the sections are formed with upwardly projecting ridges extending in the direction between the rows.

7. The packaging apparatus defined in claim 6 wherein the ridges are of upwardly pointing triangular section.

8. The packaging apparatus defined in claim 2 wherein the conveyor section are rigid plates that are hinged together about axes extending perpendicular to the direction.

9. The packaging apparatus defined in claim 8 wherein the plates each have an upper face provided with a low-friction coating.

10. The packaging apparatus defined in claim 1 wherein the device is provided with a plurality of suction grabs each for picking up a respective one of the objects.