Combination weighing apparatus in a packaging machine

Abstract: Assembly of buckets for weighing a product in a machine for packaging said product, including at least a first (A) and a second (B) row of buckets, wherein each bucket (A n ) of a row is in communication for the downwardly passage of the product (12) with a corresponding bucket (B n ) of the other row. In the assembly of buckets each of said buckets (A n , B n ) has a slanted surface (110) for sliding of the product (12) and the buckets (A n , B n ) of the rows of buckets (A,B) in respective communication for the passage of the product (12) are positioned to convey the product (12) along a downwardly conveying path comprising said sliding surfaces (110) of the corresponding buckets (A n , B n ), so that relevant vertical failings of the product (12) are avoided.

Description: The present invention relates to an assembly of buckets for weighing the product in a machine for packaging a loose product or one which is in pieces, of the type comprising at least a first and a second row of buckets, wherein each bucket of a row is in communication for the downwardly passage of the product with a corresponding bucket of the other row. Assemblies of buckets of the type referred above have already been used for some time in automatic bagging or packaging machines. According to a known configuration, the buckets have a lower unloading opening closed by one or two tilting doors which open on command of suitable means to allow the material to fall into the corresponding bucket of the lower row of buckets or into a lower funnel-shaped collection element which collects the material and conveys it to the underlying packaging zone. According to a known arrangement, the corresponding buckets, which unload the material one into the other, are perfectly aligned vertically one above the other and the material released by one of these falls from a considerable height into the one below, hitting with notable force the doors of the bucket below. This fact is extremely disadvantageous for some types of material to be packaged, for example food products in general such as biscuits, sweets of various types and others, which may, following the impact, break andlor splinter and thus become unusable for sale, with serious economic damage forthe manufacturing firms. EP-A - 075479 and EP-A - 0109844 disclose an assembly of buckets for combinatorial weighing wherein the product is conveyed along a downwardly conveying path formed by the slanted surfaces of the buckets acting as sliding surfaces. EP-A - 0140624 discloses the assembly of buckets even disposed in circular rows, wherein the product is still conveyed along a downwardly conveying path formed by the slanted surfaces of corresponding buckets. The object of the present invention is that of providing an assembly of weighing buckets in a packaging machine which overcomes the present disadvantages in the traditional bucket arrangements and more particularly that of providing an assembly of weighing buckets whereby also fragile products, such as for example the aforementioned biscuits and various types of sweets or others, may be treated in view of their packaging, without damage being caused which forces rejection of a large quantity of the products to be packaged. The previous object is achieved by providing, according to what is disclosed in claim 1, an assembly of buckets for weighing a product in a machine for packaging said product, including at least a first (A) and a second (B) row of buckets, wherein: each bucket (A n ) of a row is in communication for the downwardly passage of the product (12) with a corresponding bucket (B n ) of the other row; the buckets (A n , B n ) of each row of buckets (A, B) are aligned along respective circular lines, the corresponding buckets (A n , B n ) of the rows of buckets (A, B) are arranged along a line in the form of a substantially cylindrical spiral, the buckets (A n , B n ) of the rows of buckets (A, B) in respective communication for the passage of the product (12) are positioned to convey the product (12) along a downwardly conveying path, characterized in that said conveying path comprises a slanted surface (110) of each of said buckets (A n , B n ) for sliding of the product (12) without vertical fallings of the product along said conveying path, and said sliding surfaces (110) of the corresponding buckets (A n , B n ) of the rows of buckets (A, B) are aligned each to the other. A preferred embodiment is subject of the dependent claim 2. In this way, in fact, the product to be packaged is not fed by one bucket to the other through vertical falling as occurred according to the prior art, but is contrarily forced to slide downwards along successive slanted surfaces which accompany it in its sliding without it being subjected to impact and thus without being damaged when moving from one bucket to the other. The present invention will be made clearer on reading of the following description, relating to a preferred embodiment of the invention, to be read with reference to the accompanying drawings, in which: Figure 1 is an elevated view of a packaging machine using a preferred embodiment of the assembly of buckets of the present invention; Figure 2 is a perspective view of the preferred embodiment of the assembly of buckets of the present invention; Figure 3 is a perspective view of a single series of weighing buckets of the preferred embodiment of the assembly of buckets of the present invention. 10 in Figure 1 denotes the support framework of a generical machine for packaging a product 12 in pieces, which product is fed from above by means of a conveyor belt 14 or other and passed into an upper feed hopper 16 of the machine wherefrom it is transferred, via suitable channels 18, to the weighing section 20, comprising the assembly of buckets of the present invention. The packaging machine has, in series with the weighing section 20, a funnel-shaped collection element 22 which conveys the weighed portions of product into a special pipe 24 outside whereof a tubular strip 26 in a heat-sealable material is made to run in the zone below it. The pipe 24 intermittently fills the tubular strip 26 with predefined portions of product, while a sealing unit 28, comprising opposite welding plates 30, welds the opposite edges of said strip 26 providing individual packages or bags 32 containing a predefined portion of the product 12. With reference also to the following Figure 2, which shows only the channels 18, the funnel-shaped collection element 22 and the assembly of buckets 20 of the present invention positioned between them, it can be seen that in the preferred embodiment shown here said assembly of buckets has a first upper row of buckets, denoted by A, relating to buckets of prebatched material, a second intermediate row of buckets, denoted by B, relating to actual weighing buckets and a third lower row of buckets, denoted by C, relating to auxiliary buckets used for calculating the combinations of weights in view of forming the portion of predefined weight to be packaged. As indicated in the preferred embodiment shown here, the buckets of each row of the assembly of buckets 20 are arranged along horizontal circular lines in a number equal to 16 for each row. They may however consist of any number of elements, as also they could in principle be arranged on polygonal, non-circular lines, or those of another kind. Moreover it should be noted that the number of rows of buckets present in the weighing section 20 could also be different from the three of the preferred embodiment shown here. In some weighing sections two rows of buckets could in fact be used or, albeit improbable, more than the three rows of the preferred embodiment shown. As shown in the figures, each bucket of the upper row unloads the material into a respective bucket of the lower row. For example bucket A1 of the upper row A unloads the material into the bucket B1 of the intermediate row B, which in turn unloads into the bucket C1 of the lower row C which unloads into the funnel-shaped collection element 22. For convenience of description, we shall define the assembly of the three buckets A1, B1, C1 as the first weighing series; sixteen weighing series are foreseen in the preferred embodiment shown here. In the figures, in order not to complicate the drawings excessively, in addition to the first weighing series only the weighing series consisting of buckets A2, B2, C2 and A16, B16 and C16 are indicated. As shown more clearly in Figure 3, each of said buckets A1, B1 and C1 of the first weighing series (the same observations apply to the other series of buckets) have a respective hollow box-shaped body 102 of a general wedge shape and with an upper opening 104 for feeding the material, and a lower opening 106 for unloading the material, closed by a tilting door 108 which can be opened for unloading the material contained in the bucket. The hollow box-shaped body 102 of each bucket is made in metal sheet and has substantially triangular lateral walls 110 and a slanted back wall 112 which defines a slanted surface for the support and sliding of material. Said slanted surface for sliding 112 ends below at said opening for unloading the material 106 provided in a front vertical wall of the box-shaped body. The abovementioned walls of the box-shaped body of each bucket extend above with short peripheral walls bordering in their interior said feed opening 104. In bucket A1, like the other buckets in its row, rectangular lateral walls 116 are provided and front and rear end walls 118 with a general pentagonal shape, with the upper edge of said front and rear walls 118 which extends higher than the upper edge of the lateral walls 116. Overall, walls 116 and 118 of the bucket A1 are slightly flared upwards. In bucket B1, like the other buckets in its row, lateral walls 120 and front and rear end walls 122, 124 respectively are provided, all with a general rectangular shape. The lateral walls 120 and the rear wall 124 are flared upwards, while the front wall 122 is slanted inwards. The upper rear wall 124 is substantially slanted at the same angle of the back wall 112 of the corresponding bucket A1. In the bucket C1, like the other buckets in its row, lateral walls 126 and front and rear end walls 128, 130 respectively, all with a general rectangular shape, are provided. Said upper walls 126, 128, 130 are flared overall upwards with the rear wall 130 which is slanted substantially in the same way as the back wall 112 of the bucket B1. The upper face inside the bucket of said rear walls 118, 124, 130 defines the upper part of the surface for support and sliding of the material of said buckets. In the preferred embodiment shown here, said buckets A1, B1, C1 corresponding one to the other and their respective sliding surfaces, as also all the other corresponding buckets, are arranged along a substantially spiral line, with the respectively underlying buckets B1 and C1 which have their respective opening for feeding material 104 near the outlet opening 106 of the correspondingly upper bucket A1 and B1 respectively that is to say, as shown, with the lower front edge of each back wall 112 of the buckets A1 and B1 which extends inside the openings 106 of the bucket B1 and C1 respectively, remaining near the internal face of the respective short rearwalls 124 and 130. As shown, the tilting doors 108 for closure of each bucket have vertical perforated tabs 132 for attachment to the body of the bucket and which extend above the door, arranging themselves outside of the lateral walls 110 of the buckets. The holes of said attachment tabs are inserted in jointed pins 134 which extend outwards from the front upper vertex of said lateral walls 110. Suitable means for controlling opening-closure of said doors 108 are provided but not shown in the figures. This arrangement of the buckets of each weighing series along a spiral line allows the provision of an assembly of weighing buckets which, in addition to defining a route substantially without impact for the material, has extremely small overall dimensions, defining an assembly, substantially inscribable inside a cylinder, which does not occupy excessive spaces in working areas. Should however said rows of buckets be ordered according to any alignment, it will be sufficient, in order to achieve the objects of the present invention, for the slanted surfaces for support and sliding of the material of the respectively upper buckets to be positioned so as to convey the material towards the respectively underlying element, in a peripheral direction of the assembly of buckets. It is obviously understood that what has been written and shown in reference to the preferred embodiment of the present invention has been given purely by way of a non- limiting example of the principle claimed.

Claims: Assembly of buckets for weighing a product in a machine for packaging said product, including at least a first (A) and a second (B) row of buckets, wherein: each bucket (A n ) of a row is in communication for the downwardly passage of the product (12) with a corresponding bucket (B n ) of the other row, the buckets (A n , B n ) of each row of buckets (A, B) are aligned along respective circular lines, the corresponding buckets (A n , B n ) of the rows of buckets (A, B) are arranged along a line in the form of a substantially cylindrical spiral, the buckets (A n , B n ) of the rows of buckets (A, B) in respective communication for the passage of the product (12) are positioned to convey the product (12) along a downwardly conveying path, characterized in that said conveying path comprises a slanted surface (110) of each of said buckets (A n , B n ), for sliding of the product (12) without vertical fallings of the product along said conveying path, and said sliding surfaces (110) of the corresponding buckets (A n , B n ) of the rows of buckets (A, B) are aligned each to the other. Assembly of buckets according to the previous claim, characterised in that said sliding surfaces (110) of the corresponding buckets (A n , B n ) of the buckets rows (A, B) elongate along a line in the form of a substantially cylindrical spiral.

Inventors: SIMIONATO PAOLO, SIMIONATO, PAOLO
Applicants: SIMIONATO SPA, SIMIONATO S.P.A.
Application year: 1996
Main classification: G01G19
IPC codes: G01G19