GB2072635A - Procedure for gathering objects, such as product packages for instance, and picking machine - Google Patents

Abstract

Regular arrays of articles, e.g. product packages, are transferred from pallets on to a conveyor, e.g. 3, by means which select the required number by moving the excess in one layer to one side, e.g. on to a shelf 4. <IMAGE>

Description

SPECIFICATION Procedure for gathering objects, such as product packages for instance, and picking machine Picking is understood to be a function wherein product-specifically stored packages are gathered to form customer-specific batches. The picking of packages is one partial function of gathering.

Fairly little progress has been made in mechanizing and automating the gathering function. Picking is expressly that work step which has proved difficult to speed up in a sufficiently reliable and advantageous way. It is of course a phenomenon encountered in all branches of technology: that increase of capacity causes an even steeper rise of price. But this is only applicable if one adheres to the same previous type of technology.

Up to date there have been used in gathering, on the side of pure manual work, various picking vehicles, but in the greater part of these all that has been done is to substitute driving for the picker's walking. A few more advanced models are fitted with mechanisation of the picking motions. It is fairly obvious that these pieces of equipment cannot have any large capacity.

As a consequence of the comparatively primitive construction of the equipment, its automation is impossible, or it is extremely expensive at least.

It is also possible to design pieces of apparatus resembling a typical industrial robot and which are able to pick, one by one, the desired number of packages from a load palletforinstance. But their characteristic features are complex construction and high price. This is particularly emphasized when goods are being picked from a pattern-palleted load pallet. Moreover, the capacity of these robotresembling means is fairly low, as a result of the complexity of their motion series and of the limited amount they are able to pick at any one time.

With a view to achieving higher capacity, degree of automation and reliability at reasonable cost, the method disclosed in the following and the apparatus carrying out this method have been invented.

The procedure of the invention is characterized in that the exact number of pieces to be delivered is obtained by moving to one side that potential excess which has accrued from picking by row or by course.

Packages are picked from a pallet or equivalent, for each shipment batch, in a number at least equivalent to requirements, in that the picking is carried out by whole rows or courses and the excess quantity is moved to one side to await the next picking run. This enables the correct number of pieces to be supplied for shipment. On the next picking run, the pieces that were moved aside are at disposal, if required, with utmost speed.

The following advantages are gained by this method: - Picking may always be done from a full row or course, whereby the picking number and its controls may be relatively simple of their design; - As a corollary hereof, it will be easy and inexpensive to achieve high speed in picking; - Taking up pieces that have been moved aside is accomplished with speed whenever required. Especially the taking up of small numbers of pieces will then take place in decisively shorter time than merely from the load pallet; - Using the pieces which have been moved aside may obviate the starting on a new row or course, thereby reducing the average time per piece.

The invention also concerns a picking machine for carrying out the procedure. The picking machine is characterized in that it comprises a picking member, an equalizing conveyor, side shelves or conveyors with filling and discharging means for fractional row deliveries for supplying pieces onto a connecting conveyor.

The invention is described in the following with the aid of an example, with reference being made to the attached drawings, wherein:- Figure 1 presents a picking machine in elevational view.

Figure 2 shows the picking machine in top view.

The actual picking operation is performed by the picking member. Its design is determined by the properties of the packages that have to be picked and by the palleting pattern. In the present embodiment, the palleting pattern 10 is a straight 3 by 3, in Figure 2. The packages consist of cardboard; weight about 10 kg each; the product is not sensitive to handling. In this case there were selected for gripping members, paws pressing from the sides against each row and, for additional safety, suction cups for the centremost row. The design of the paws is such that while pressing they lift the packages at the same time.

The picking member 1 picks up packages by the row or by the course (here, 1 to 3 rows at a time) and moves along its guides 11 to the initiai end of the equalizing coneyor 2. The picking member 1 deposits here the packages it has picked, one row at a time. The task of the equalizing conveyor 2 is not only to move the packages onto the connecting conveyor 3 but also to take care of a uniform goods flow so that the capacity of the picking member 1 need not be wasted on waiting for the connecting conveyor to become empty and that the picking member 1 may instead operate quite with its own rhythm. In the case depicted here, the equalizing conveyor 2 is inclined and it has been provided with belts, which run freely under the weight of the package. The belts may be mounted with a slight divergence whereby the packages are separated.

The equalizing coneyor 2 may naturally be of any other kind as well.

The connecting conveyor 3 carries the packages that have been picked, to be customer-specifically packed. It is here an accumulating roller conveyor.

Another type of conveyor may equally be applied.

The side shelf 4 is intended for the keeping in storage of those pieces which are left over from picking by row or by course. Here, as the palleting pattern 10 is simple and picking by row is practiced, a mere simple shelf is enough. If the pallet is pattern palleted or otherwise whole course picking is employed, it is indicated to use instead of the side shelf 4, gathering point-specific side conveyors which can accommodate at last one course-full of packages each. Use of a side conveyor is also indicated if the numbers of units picked of each sort are greatly variable and if picking of small numbers is frequent.

Small batches are in that case obtained straight from the side conveyor, without performing any picking from the pallet.

In the embodiment presented, where the side shelf 4 has been designed for one row of packages at the most, transfer onto the side shelf 4 is by the aid of pushers 5, operating e.g. with compressed air. The transfer of packages from the side shelf 4 to the connecting conveyor 3 is accomplished with the aid of pushers 6. The number of pushers 5 and 6 must be at least one per each line of packages on the load pallet. In whole course picking, that is when a side conveyor is used instead of the side shelf 4, it is proper for the side conveyor to be one which conveys in two directions. The pushers 6 are naturally not needed then.

In the embodiment presented here, a certain compromise has been made with cost consideration in mind as regards the capacity, and the picking machine itself has been fitted with forks 7 lifting the load pallet, these forks moving along a vertical guide 12. The task of the lifting forks 7 is to bring the topmost course of packages on the pallet into reach of the picking member 1. Furthermore, the forks 7 lift the emptied pallet onto the picking member 7, which transports it to the track 9 for empty pallets. In this embodiment, furthermore, the forks have been provided with pulling claws 8 which are able to pull the next pallet to the picking station. A higher capacity would be achieved by providing each product station with a lifting means of its own, but the difference has no significance in view of the whole.The capacity of the picking machine as it is is adequate from the viewpoint of the entire gathering system.

The availability of packages which have to be picked up may be implemented in other ways as well, e.g.

by arranging for a lifting motion of the picking member 1 itself. This however renders the picking member 1 heavier and more complex. Moreover, the time necessary for overcoming the difference in height is then in series with the other partial times of the picking process, not in parallel as it is now. That will impair the capacity. But this design is appropriate if the goods to be picked up is only packed in an open-top crate.

It is obvious that the embodiment of the picking machine may even quite considerably deviate from what has been presented above and that it may still carry out a procedure according to this claim.

If the object of picking is a load pallet on which have been palleted, in accordance with the palleting pattern 10, ten courses of packages with a height about 12 cm, i.e., 90 pieces per pallet, the mean of the picking times of batches from 1 to 90 pieces is found to be about 2.9 seconds per piece. If the size of the picking batches is limited to be within the brackets of 10-81 pieces, the mean of the picking times will be 2.2 seconds. In the special instance conerned here, the size of the picking batches varies on either side of 40, transgressions of the limits of 10 and 81 being extremely rare. The picking times stated include also the travel of the picking machine from one sort to another. Hereby a capacity of about 1600 pieces per hour is attained.

It is well feasible with such capacity to keep between 2 and 4 conventional packaging machines supplied with goods.

The picking procedure and apparatus of this patent application may however be applied to greatest advantage in connection with a gathering procedure and apparatus as disclosed in the patent application No. 800633.

Claims (10)

1. Procedure for mechanically picking pieces, such as product packages, from a load pallet filled by courses in accordance with a given regular pattern orfrom equivalent, the picking always taking place by whole rows or courses, characterized in that the exact number of pieces to be delivered is obtained by moving to one side that potential excess quantity which has been created in the picking by rows or by courses.

2. Procedure according to claim 1, characterized in that in addition to the picking from a load pallet, or instead thereof, pieces that have been put aside are taken up in order to deliver the desired number.

3. Procedure according to claims 1 and 2, characterized in that control and supervision of the procedure are perfomed with a computer in real time (on line).

4. Picking machine for carrying out a procedure according to claim 1, characterized in that the picking machine comprises a picking member, an equalizing conveyor, side sheives or conveyors with filling and discharging means for fractional row deliveries for supplying pieces onto a connecting conveyor.

5. Picking machine according to claim 4, characterized in that the pallet to be picked is lifted to be within reach ofthe picking member.

6. Picking machine according to claim 4, with a picking member provided with clamping paws, characterized in that the paw mchanism as it clamps also simultaneously lifts the pieces with the same action means and with its control.

7. Picking machine according to claim 4, characterized in that the equalizing conveyor is dimen signed to set the timing of the picking member free from the timing of the connecting conveyor.

8. Picking machine according to claim 4, characterized in that the load pallet lifting member has been provided with pulling claws for pulling the next load pallet to the picking station.

9. A method as claimed in Claim 1 substantially as hereinbefore described.

10. A picking machine substantially as described herein with reference to and as illustrated by the accompanying drawing.