WO1989000953A1

WO1989000953A1 - Apparatus for cleaning cylindrical cans

Info

Publication number: WO1989000953A1
Application number: PCT/NL1988/000037
Authority: WO
Inventors: Sjoerd Meijer
Original assignee: Sjoerd Meijer
Priority date: 1987-08-04
Filing date: 1988-08-03
Publication date: 1989-02-09
Also published as: EP0326601A1; NL8701842A

Abstract

Apparatus for the cleaning of substantially cylindrical cans (5), comprising an elongate guideway for the cans, feeder (3) and removal (4) conveyors connecting to the guideway, means (8, 9) for causing a movement of the cans along the guideway, whereby the cylindrical walls of the cans are in a state of forced contact with a fixed rail (10) of the guideway, and at least one rotatingly driven roller brush (12, 13), mounted substantially parallel to the guideway, with its brush surface protruding into the guideway.

Description

APPARATUS FOR CLEANING CYLINDRICAL CANS

The invention relates to an apparatus for cleaning substantially cylindrical cans. During manufacturing processes in which a product is packed in cans, it is generally inevi¬ table that some of the product will adhere to the outside of the can. This phenomenon occurs particularly when the product is in powder form, for example a milk, powder.

In general this is undesirable. In the case of milk powder, this can attract moisture and putrefy, so that after the can has been opened its contents also very quickly become contaminated and also putrefy. It is therefore desirable to clean ad ering product from the cans after filling.

In the past attempts have been made to clean cans of an adhering product, in particular of adhering powder, by blowing the powder off the cans with compressed air. In the case of a fine powder however this has proved neither reliable nor economically feasible.

The invention has therefore for its object to pro¬ vide an apparatus for the cleaning of substantially cylindri¬ cal cans, which operates effectively and efficiently. This is achieved in an apparatus according to the invention by an elongate guideway for the cans, feeder and removal conveyors connecting to the guideway, means for causing a movement of the cans along the guideway, whereby the cylindrical walls of the cans are in a state of forced contact with a fixed rail of the guideway, and at least one rotatingly driven roller brush, mounted substantially parallel to the guideway, with its brush surface protruding into the guideway. Through the movement of the cans along the guideway with their cylindrical walls in forced contact with a fixed rail of the guideway, the cans acquire a rotary motion. In this manner the entire circumferential surface of the cans comes into contact with the roller brush and is thereby brushed clean. This manner of cleaning the cans has proved satisfac ory. The apparatus can be relatively simple in construction and its energy consump- tion is very limited. The cost of cleaning the cans is thus correspondingly low.

It is recommended that the step according to claim 2 be taken. The brushed-off product is removed entirely as a result, and can for instance be filtered at a suitable place out of the extracted air. The apparatus thus remains free of contamination to a considerable extent.

A particularly favoured embodiment of the invention Is characterized in claim 3. During passage of the can along the first roller brush, the first half of the can is cleaned, while the can can be held in position and guided by means of the second half, and immediately thereafter the second half is cleaned while the can is similarly held in place and guided by means of the first half. On account of the indicated rota¬ tional direction of the roller brushes, any quantity of pro- duct which may have been smeared by the first roller brush from the first half onto the second will be removed by the second roller brush without any difficulty.

In order to ensure that the desired rotation of the cans is performed rapidly and reliahly, it is recommended that the step according to claim 4 be applied.

The necessary forced contact with the fixed rail thereby comes about in a favourable manner when the fixed rail Is in each case mounted on the side of the roller brush at the level of the extremity of that half of the height of the cans which is not brushed by the respective roller brush. It is recommended that the fixed rail is formed by an angle—section bar. This holds the cans fast in an accurate and reliable way.

The effect of the step as claimed in claim 7 is that should any of the product adhering to the second drive belt be transferred to a can, this quantity of product will still be removed by the last portion of the second roller brush. Through mass inertia, the can continues rotating for a while after the forced driving in contact with the fixed rail has ended . The end faces of the cans, and, particularly when the end face comprises a clamping lid, the groove between the edge of the lid and the rim of the can, can also be cleaned in an effective manner when the step according to claim 8 is employed . The invention will be further elucidated in the following description of several embodiments which are illus¬ trated in the drawings.

Figure 1 sho s a perspective view with parts broken away of an apparatus according to a preferred embodiment of the invention.

Figures 2 and 3 are partial sections along the lines II-II and III-III respectively in figure 1.

Figures 4 and 5 show schematically a top view and a side view respectively of an apparatus according to a differ- ent embodiment of the invention.

The apparatus shown in figure 1 is intended for the cleaning of cans 5. These cans have previously been filled with a product in powder form, and during filling some powder can become deposited on the outside of the cans 5. The ap- paratus 1 comprises a guideway 2, which is substantially a rectangular "tunnel" with a somewhat larger cross section than the axial cross section of the can 5.

The cans 5 are supplied to the guideway 2 by a feed¬ er conveyor 3, and are removed thence by a removal conveyor 4. The apparatus 1 can easily be incorporated into an existing filling installation, by interrupting a conveyor belt which is already present therein, and by situating the cleaning apparatus 1 at that point.

In the guideway 2, the cans 5 are guided by a number of guide rails, in particular by two guide rails 6 on the underside and one guide rail 7 on the top. The apparatus fur¬ ther comprises a guide rail designated as the "fixed rail", which has a specific function to be described below. In the right-hand part of the apparatus shown in figure 1, correspon¬ ding to the section shown in figure 2, the fixed rail is indi¬ cated by 10 and is situated close to a bottom corner of the cans 5. In the second part of the apparatus, corresponding to the section shown in figure 3, the fixed rail is situated close to the top corner of the cans.

Two roller brushes 12, 13 are arranged as shown. The centre lines of these roller brushes extend parallel to the guideway. As revealed by figures 2 and 3, the brush surfaces of the roller brushes 12, 13 protrude into the guideway 2. Arranged opposite each roller brush 12, 13 is a drive belt 8, 9, which grips the cylindrical surface of the cans opposite the respective roller brush. In order to ensure a good contact with the cans along the entire length of the respective drive belt 8, 9, a supporting strip 20, 21 is fitted behind the operative part of each drive belt. The drive belts 8 and 9 are driven through a common drive shaft 18 by a motor 19. The driving takes place such that the speed of movement of the drive belts 8, 9 is equivalent to at least twice the speed of the feeder and removal conveyor belts 3 and 4. Namely since the cylindrical walls of cans 5 come into forced contact with the fixed rail 10 at the entrance to the apparatus and are grasped by the drive belt 8, the cans 5 will come into rota- tion and roll along against the fixed rail 10. In order to ensure that the speed of passage through the apparatus is at least equal to the speed of the feeder conveyor 3, the drive belt 8 and naturally the drive belt 9 which follows it must have at least twice the speed of this feeder conveyor belt. As shown in figure 2, the first roller brush 12 is situated at the level of the upper half of the height of the cylindrical wall of the can, and the drive belt 8 is, as noted earlier, placed at the same height as the roller brush 12 on the opposite side of the guideway to that roller brush. It has been found that as a result of co-action of the drive belt 8 and the fixed rail 10, the cans very quickly reach the desired rotational speed. This is important becaus in known production installations the cans 5 are transporte at a high speed, for example of the order of 300 cans pe minute. The passage time of each can 5 through the apparatu 1 is thus very short.

It will be apparent that while the cans 5 roll alon the fixed rail 10, the upper part of the cylindrical surfac thereof is brushed clean. Since the top cylinder wall is sea folded onto the can after the filling thereof, this is clea and requires no further cleaning.

Each roller brush 12, 13 is provided with a cap 14 16, which substantially encloses the respective roller brus except for the portion protruding into the guideway 2. Eac cap 14, 16 is connected by an individual line 15, 17 to suction means, such that the powder brushed from the cans b the respective brush will be extracted.

After each can has passed the first roller brus 12, the upper half of the wall of each can is in a cleane state. In the second part of the apparatus, at the positio of the second roller brush 13, the lower half is cleaned.

As is particularly revealed by figure 3, the rolle brush is therefore positioned at the level of the lower hal of the height of the cans 5, and the associated drive belt is mounted at the same level on the other side. The fixe rail 11 is here positioned at the top corner. Through the co operation of drive belt 9 and the fixed rail 11, each can rolls further along against the fixed rail 11 and is thereb brushed clean by the roller brush 13.

As figure 3 shows, an extra brush strip 22 can b arranged, which cleans the lower edge of the can during rota tion along the brush strip.

As seen in figure 2, the roller brush 12 is drive in a clockwise direction, so that its brush surface moves downwards along the can 5. The roller brush 13 rotates in the same direction. As figure 1 shows, both roller brushes are driven by means of a motor 24. The second drive belt 9 ends at a certain distance (in the direction of movement of the cans) before the end of the second roller brush 13. Through its mass inertia the can continues rotating for a little while after passing the drive band 9, so that in the last part the can 5 is cleaned without it being driven. In this way any powder transferred from the drive band 9 to the can is also removed. After a time powder that has been picked up from the not yet cleaned part of the cans 5 may come to adhere to the belt 9. A fixed brush, which can be connected to the suction means, may optionally be moun¬ ted for cleaning the drive bands 8, 9.

As indicated in figure 1, a tensioner 25 grips onto the non-operative part of the drive band 8, which tensioner keeps the drive band 8 at maximum tension, through a tension roller 26 subjected to loading by the spring 27. The drive band 9 can of course be equipped with a similar device.

The apparatus 30, as is schematically shown in fig¬ ures 4 and 5, makes use of gravity to cause the movement of the cans along the guideway. The feeder belt 31 lies at a higher level than the removal belt 32, so that the cans 33, while passing through this height difference in the apparatus 30, are propelled by gravity.

Immediately preceding the feeder belt 31 is a per se known construction of guide bars 34, which tilts the cans 33 through a quarter turn. After this tilting, the cans 33 arrive in a channel 35 with standing edges 36. This channel forms the previously mentioned fixed rail of the apparatus, and the cans 33 roll down in the manner indicated along the channel 35. Mounted above the channel is a somewhat diagonally dis- posed roller brush 37 which is driven in the direction indi¬ cated by means not shown. In a similar way to the apparatus described earlier, a cap 38, connected to a suction means, is arranged around the roller brush 37. Through the somewhat diagonal disposition of the roller brush 37, the entire cylin- drical surface of the cans is brushed during movement along the channel 35. Following the channel, a further construction of guide bars 39 is mounted, which tilts the cans back again through a quarter turn as they pass along. In this manner the cans 33 return to the same orientation as that in which they were delivered onto the feeder belt 32.

The channel 35 can be provided near the standing edges 36 with friction-increasing material such as strips of rubber, in order to ensure that the cans 33 come rapidly into rotation. Since the positive drive such as that in the appa¬ ratus of figure 1 is absent from the apparatus 30, the latter is less suited to high transport speeds. At lower transport speeds, for example during the handling of larger cans, and when a suitable height difference between the feeder belt and the removal belt can be realized, the apparatus 30 is suitable for application on account of its simple construc¬ tion.

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Claims

1. Apparatus for the cleaning of substantially cyl indrical cans, characterized by an elongate guideway for th cans, feeder and removal conveyors connecting to said guide way, means for causing a movement of said cans along sai guideway whereby the cylindrical walls of said cans are in state of forced contact with a fixed rail of said guideway, and at least one rotatingly driven roller brush mounted sub stantially parallel to said guideway and with its brush sur face protruding into said guideway.

2. Apparatus as claimed in claim 1, characterized i that the roller brush Is provided with a cap which substan tially encloses the portion of the respective roller brus not protruding into the guideway and which is connected to suction means.

3. Apparatus as claimed in claim 1, characterized i that the apparatus comprises in the direction of transport first roller brush at the level of a first half of the heigh of the cylindrical wall of the cans and a second roller brus at the level of the second half thereof, wherein said firs roller brush is driven in the direction such that the portio thereof protruding into the guideway moves towards the secon half of the can height, and wherein said second roller brus is driven in the same direction.

4. Apparatus as claimed in claim 3, characterized i that the means for causing the movement of the cans compris a drive belt arranged opposite to and at the height of eac roller brush which grips the cylindrical wall of said cans o the opposite side to said roller brush.

5. Apparatus as claimed in claim 4, characterized i that the fixed rail is arranged on the side of the roller brush in each case at the level of the extremity of the half of the height of the cans which is not brushed by the respec¬ tive roller brush.

6. Apparatus as claimed in claim 5, characterized in that the fixed rail is formed by an angle-section.

7. Apparatus as claimed in claim 4, characterized in that the second drive belt ends at a certain distance before the second roller brush.

8. Apparatus as claimed in claim 1, characterized by a strip brush extending parallel to the guideway with its operative surface acting on a circular surface of the cans.

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