GB2305734A - Combination weighing machine - Google Patents

Abstract

Food items are fed into three parallel channels of a feed conveyor (7), and are caused by disc assemblies (18,19) connected to endless chains (20) to occupy transverse rows, which are guided down taut elastic members stretched between each pair of discs (18), to a reciprocating transfer mechanism (31) which delivers the items to the orientated buckets (8). The buckets (8) are lowered in stabilising stations prior to the weighing stations (9), and are then conveyed round cogwheels (15,16,6) to the top section where the buckets (8) are selectively tipped at unloading stations (10) to unload the items onto transverse conveyors (11) to form the weight combinations.

Description

DESCRIPTION OF INVENTION IMPROVEMENTS IN AUTOMATIC WEIGHING MACHINES FOR SUNDRY PRODUCTS, PARTICULARLY FOOD PRODUCTS FIELD OF THE INVENTION The present Patent of Invention relates to improvements in automatic weighing machines for sundry products, particularly food products, applicable to an extensive range of products, such as peppers, onions, potatoes, garlic, citrus fruits, Brussels sprouts, apples, walnuts, green beans and, broadly speaking, fruits, vegetables et al. and all types and kinds of food products and any products or objects whatsoever of varied sizes that are to be subsequently packaged with or in a preset total weight or quantity, with likewise pre-set tolerances.

BACKGROUND OF THE INVENTION Weighing machines for food and other products are known to have a rather large number of buckets that are fed with the products to be weighed, which are conveyed from a machine product inlet and unloaded onto said buckets in which weighing is carried out as appropriate.

These known weighing machines have an electronic computer unit calculating the potential combinations of weights of the products lying on such buckets and selecting those yielding a sum of weights of the products arranged thereon, i.e. their total weight, being closest to the desired weight, ordering their unloading onto an outlet conveyor fitted in the machines. The emptied buckets are newly filled with products.

The means conveying the buckets consist of pairs of parallel roller chains each supported by end cogwheels, a number of supports being provided between said two chains fitted with short, inwardly directed shafts in transverse alignment on which the buckets are suspended.

Both roller chains have guide means for their downward deflection along a U-shaped path arranged on the weighing unit, the buckets being therefore lowered vertically in this area and temporarily released from the roller chains, bearing on the weighing unit plate or platform, thereafter to be newly lifted and conveyed by the roller chains.

This strategy is what is known as "associative weighing" in which products -lying in buckets- pass by several weighing points and an electronic calculator seeks a combination of weights yielding a total real value closest to the desired nominal weight, with the pre-set tolerance. The object of European Patent no.

81900325 of the Japanese firm Kabushiki Kaisha Ishida Koki is one such weighing machine, particularly the one described hereinbefore.

Given the very constitution of the weighing machine described, its forward speed must be rather low in order to ensure a certain accuracy in weighing the buckets with the respective products contained therein and, though the roller chains may be precisely stopped intermittently, to ensure a certain stabilisation of full buckets and indeed empty buckets that are to be tared, to eliminate or reduce to the utmost inertial forces stemming from the very movement of the full or empty buckets, which would alter the value of their true weight, which stopping and starting moreover causes prejudicial mechanical stresses.

The actual applicant is the holder of Spanish Patent of Invention no. 500,951 which relates to improvements in automatic weighing machines for fruits and like products, essentially characterised by comprising, according to claim 1: a) a feed inlet having several channels ending in means where the product to be weighed is retained and held, followed by horizontal conveyor means distributed into as many groups as there are channels, which groups are out of step with each other in moving and carry the relevant product from the respective retaining means to appropriate weighing means and then from the latter means to vertical conveyor means, also integrated by as many groups as there are channels, and lift the previously weighed product towards ramps superimposed at different heights, flowing into respective stores fitted with means to unload the same, another ramp lying above the former ramps to lead rejected products (due to their inadequate weight) towards the machine inlet, the vertical conveyor means having selective means allowing the product to be unloaded onto the relevant ramp, horizontal transverse conveyor means being arranged below the stores for the outlet of the product in batches having a pre-set adjustable weight;; b) a programming and processing unit setting the strategy to be followed from a desired final weight of each batch of units of a product to be weighed, and taking into account the true weight of the units obtained in the machine, linking means between the processing unit and the various machine parts to coordinate and control the same, especially as regards selective unloading of each batch of previously weighed product units into a particular store or into the reject area, availing of the selective means included in the vertical conveyor means and along the corresponding ramps; and c) drive means for the various machine parts, and a structure supporting the same.

The strategy followed by the weighing machine having the improvements subject of Spanish Patent of Invention no. 500,951 in operation, is the so-called "accumulative weighing" and in it the programming and processing unit takes into account at all times the true weights of the product units that are temporarily housed in all the stores with which said weighing machine is purposely fitted, combining the same mathematically with the true weights of the product units as these are being weighed.

The advantages of said weighing machine are, inter alia: the possibility of obtaining batches of fruits having a pre-set weight, within established limits, with products that are difficult to weigh because there are weight differences between each unit and the latter cannot be divided (oranges, lemons, apples, etc.); and a fully automatic weighing and final supply of batches of fruits having pre-set weights and tolerances at a high rate which by far exceeds that of machines known at the date of filing of said Spanish Patent of Invention no.

500,951; the performance of this machine is therefore very high and far less units of the product to be processed are rejected precisely due to the use of "accumulative weighing".

SUMMARY OF THE INVENTION The improvements in automatic weighing machines for sundry and particularly food products subject of the present invention are applied to the said automatic machines of the kind comprising a housing for the machine parts, means driving such parts, means feeding products at the machine inlet, conveying them along longitudinal channels and unloading them onto linear conveyor means, arranged in cyclic closed circuit and on longitudinal vertical planes, fitted with as many lines as there are channels at the feed means and lying coplanarly therewith to receive products from the respective channels, each line in said linear conveyor means having a number of buckets in which the products to be weighed shall be laid, said buckets flowing through a station weighing the full or empty buckets and stations selectively unloading previously weighed products onto corresponding transverse conveyor means, moreover comprising a programming and processing unit which records the tare of each bucket and the true weight of the product or products collected by the bucket, linking means between said unit and the relevant machine parts, as well as general guide means for the linear conveyor means, and command, control and safety means therefor; characterised as follows: longitudinally and parallelly arranged taught elastic thread-like means inserted between the product feed means at the machine inlet; means transferring the products from the feed means at the machine inlet to the buckets, provided with means lifting such products by transverse rows or alignments and means temporarily retaining such rows, both means being synchronised and controlled by the programming and processing unit; means guiding the lines in the linear conveyor means which make their respective buckets face the product transfer means; stations stabilising the buckets in the respective lines before they are weighed; means guiding the buckets in each line as they are lowered to be successively borne at the relevant stabilisation station and weighing station; sectors of the means guiding the buckets in each line, controllable by the programming and processing unit, which may be temporarily diverted relative to the adjoining rest of the guides, to bring about a selective tipping of the buckets at the relevant stations where the products contained therein are unloaded; sectors of the means guiding the buckets in each line, causing the tipped buckets to subsequently retrieve their operative position; means supporting each bucket fitted with means temporarily bearing and retaining the same, cooperating with corresponding bucket means, and with articulation means about a transverse shaft joined to the linear conveyor means, said supporting means being moreover joined to a lateral arm fitted with roller or slide bearing means in the guide means of the linear conveyor means; flexible thread-like means pulling the buckets, operative as they pass by the relevant stabilisation and weighing stations, such thread-like means being respectively joined at their ends to the buckets and their relevant supporting means; means leading the previously weighed products unloaded from the buckets on the transverse conveyor means; and selective two-way drive for the means transversely conveying the previously weighed products, such means being controlled by the programming and processing unit.

The foregoing improvements subject of the invention are optionally characterised by comprising laminar means which may in the operative position be placed over the product feed means at the machine inlet, the surface to be covered above the products being controllable, said laminar means being concealable in the non-operative position and having means for moving and means for guiding the same.

The application of the improvements to automatic machines for weighing sundry and particularly food products subject of the present invention yields the following advantages, inter alia: the feed means located at the machine inlet can convey large and small products alike; the products are smoothly and controllably transferred from the feed means to the buckets in the linear conveyor means, thereby preventing damages especially to frail products, namely for instance certain fruits; an optimum stabilisation of the full or empty buckets at the weighing station, to ensure that weighing is accurate; the ability to carry out both an "associative weighing" and an "accumulative weighing'! even simultaneously in different lines of the weighing machine; the ability to simultaneously process different products and/or products of different sizes or weights, with different outlets from the weighing machine; and the possibility of the buckets turning or swivelling about their respective hinge pin, the linear conveyor means being thereby able to have its path changed and/or diverted, reducing the length of the machine.

The improvements of the invention yield the advantages described hereinbefore, and others that will be easily inferred from the example of an embodiment of such improvements described hereinafter to facilitate the understanding of the characteristics set out above, and concurrently revealing several details thereof, a number of drawings being therefore attached which represent, for purely illustrative purposes and not to limit the scope of the invention, a practical embodiment of an automatic weighing machine fitted with the improvements of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a right-hand side elevation view of an automatic weighing machine fitted with the improvements in question, the figure showing the means guiding the buckets only in the relevant sectors, to facilitate an overview of the machine; figure 2 is an enlarged crosssection along line A-A of figure 1; figures3, 4 and 5 are each an enlarged front vertical cross-sectional detailed view of the linear conveyor means respectively through an area of the selective bucket unloading stations, a rear top end area in which vertical lowering of the buckets is about to begin and a lower end area of such lowering; figure 6 is a right-hand side elevation view of the product feed means at the machine inlet, enlarged with respect to figure 1; figure 7 is an enlarged front elevation view of the feed means of figure 6; figure 8 is an enlarged elevation view of the means driving the feed means of figure 7 and figure 9 is a detailed view along (A) of figure 8 of the drive motor means proper; figures 10 and 11 are each enlarged longitudinal sections respectively taken along the right and left-hand sides of the feed means of figure 6 and without the drive motor means; figures 12 and 13 are respectively sections along lines C-C and B-B of figure 11, albeit limited to one of the three channels of the feed means, the two others being identical; figure 14 is a plan view of one of the laminar means which may be placed over the feed means, with its displacement and guide means; figure 15 is a section along line D-D of figure 14; figure 16 is a front elevation view of the full laminar means, partly cut off; figure 17 is a partly cut-off and enlarged rear view of one of the product transfer means -the relevant temporary product retaining means being shown in phantom for the drawing to be clearer- the two other means being identical, said means lying at the rear of the product feed means; figure 18 is an enlarged view from the left-hand side, of the product transfer means according to figure 17 and figure 19 is an enlarged vertical and longitudinal section of the product transfer means according to figure 17; figures 20 and 21.

are respectively a front elevation and a left-hand side view of a bucket with its supporting means; figure 22 is a left-hand side detailed view of the machine, showing the bucket stabilisation and weighing stations, enlarged with respect to figure 1; figure 23 is a detailed view of some sectors of the bucket guide means which may cause them to be tipped at the stations where previously weighed products are selectively unloaded, enlarged with respect to figure 1, and figure 24 shows, enlarged even with respect to figure 23, a detailed view of a portion of the sector of the bucket guide means which can cause them to be tipped; figure 25 is a detailed view of the sectors of the bucket guide means causing the tipped buckets to retrieve their operative position, enlarged with respect to figure 1; figure 26 is a detailed view, enlarged with respect to figure 1, of the sectors of the bucket guide means at the lower rear portion of the machine; and figure 27 is an enlarged partial crosssection of the machine according to figure 1, namely of one of the transverse conveyor means of the previously weighed products.

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION With reference to the drawings, the automatic weighing machine fitted with the improvements of the invention comprises a housing (1) (figures 1 to 5 and 22 to 27) holding the machine parts, with suitable legs (2) to stand on the floor (figure 1) which may have adjusting means for the machine to be levelled and even means for fixing the same to said floor; and moreover comprises means (3) driving said parts, shown in figures 1 and 23, constituted in this embodiment by a gearmotor with a pinion meshing with an endless chain linking with another pinion (4) (figures 1, 2 and 23) that is in turn linked through a torque limiter to a shaft (5) (figure 2) supported in the housing (1) and each having joined at its two ends cogwheels (6) (figures 1, 2 and 23) to which relevant endless chains of the linear conveyor means are linked, arranged in cyclic closed circuit and on longitudinal vertical planes, fitted with as many lines as there are channels in feed means (7), to be described hereinafter in relation to figures 1, 6 to 13 and 17 to 19. In this example, the weighing machine has three such lines and each line incorporates a number of buckets (8) (figures 1 to 5, 20 and 21) along the same which shall be described hereinafter.The products to be weighed shall gradually be laid on the buckets in each of the lines in such linear conveyor means, the full or empty buckets flowing past a station (9) (figures 1 and 22) where they are weighed and past stations (10) (figures 1, 2, 3, 23 and 24) where the previously weighed products are selectively unloaded onto respective transverse conveyor means (11) (figures 1, 23 and 27).

The weighing machine comprises a programming and processing unit which records the tare of each bucket and the true weight of the product or products collected thereby, and means linking such unit and the relevant machine parts, and general guide means for the linear conveyor means, and command, control and safety means for the machine, including adjusting means and electrical, electronic and pneumatic connection and protection means.

The weighing machine will also have relevant covers or lids protecting the user therefrom.

The linear conveyor means are constituted by two parallel side chains, each being supported by and meshing with cogwheels (6), (12), (13), (14), (15) and (16) (figures 1, 2, 4, 5, 22, 23, 25 and 26), another parallel series of cogwheels like the above being provided, as aforesaid, located on the opposite side of the machine, such cogwheels being mounted to turn due to corresponding roller supports or the like, in turn mounted on short shafts fixed to the machine housing, save for the two cogwheels (6) which are joined, as aforesaid, at the ends of the shaft (5) (figure 2) that is made to turn by the drive means (3).

The means guiding the linear conveyor means and the buckets are laid out along the circuit travelled by the pair of endless chains of the linear conveyor means, which they guide, including the buckets in each of the lines in such linear conveyor means, which they also guide. The sectors of the bucket guide means in which there are diversions from their general path will be described hereinafter. The bucket guide means (ilk) (figures 1 to 5 and 22 to 26) are not shown throughout their path since such is obvious to one of skill and for the drawings to be clearer.

The buckets (8) in the lines integrated in the linear conveyor means are each led, in transverse alignments thereof, by transverse shafts (8a) (figures 2 to 5) joined at their two ends to the two respective endless chains of said linear conveyor means.

The means (7) (figures 1, 6 to 13 and 17 to 19) feeding the products to be weighed lie at the weighing machine inlet, are mounted in the machine housing (1) as shown in figure 1 and are upwardly fitted with a chute (7a) to receive the products that are to be transferred to the machine buckets to be subsequently weighed. Said feed means have longitudinal channels whose number is equal to that of the linear conveyor lines, namely three in this example (see figure 7) and comprise a frame (17) (figures 6, 7 and 10 to 13) in which three series of discs (18) are arranged, one per channel, shown in general schematic form in figure 7, one of the three series of discs being shown in detail in figures 12 and 13.

The discs in each series make up transversely arranged groups and each group is constituted by several equally spaced discs fixed onto a shaft (19) (figures 7, 12 and 13), the shafts in each group being assembled parallel to one another, equidistant and each joined at their two ends to endless chains (20) (see especially figures 10 and 11 for the layout of the endless chains and figures 7, 12 and 13) which pair of endless chains in each channel are mounted and driven between two pairs of cogwheels (21) and (22), each pair being joined to a shaft (22a) supported -through two end bearings- on the frame (17), thereby for one of the cogwheels (22) in each pair of the relevant channel to be linked, through another endless chain (22a) with the relevant pinion (23) (figures 8 and 9), namely three in this example, such pinions being mounted on the shaft (24) -mounted on frame (17) supports- through the same number of gears (25) which are preferably electric to be separately governed and driven.

The shaft (24) is in turn made to turn by a chain transmission linking the pinion (26) fixed to said shaft with the pinion (27) of the gearmotor (28). The pairs of endless chains (20) and the shafts (19) of the disc groups (18) are borne by and slide on top and bottom guides (29) (figures 10, 11 and 13).

Figures 10 and 11 show arrows pointing in the direction of travel of the endless chains (20) and therefore of the disc groups (18), some, though not all, of said groups being shown for the drawings to be clearer.

The feed means have elastic thread-like means (30) (figures 10 to 13) arranged with some tension and fixed at their ends to the frame (17). These thread-like means are arranged longitudinally and parallelly, and inserted among the discs (18), specifically in the open slot-like spaces existing between each pair of adjacent discs, bearing on the shafts (19) which travel below the threadlike means and along the top sector of travel of the endless chains (20), the left-hand side of figure 11 showing one such thread-like means (30) bearing on the relevant part of the shaft (19) of a transverse disc group (18).It may be convenient for the disc groups (18) to turn counter the direction of the endless chain (20), to which end they will at the frame (17) shown in figures 12 and 13 extend their top horizontal flange or flanges, thereby for the discs located at both ends of their groups to rub against the underside of said extensions of the frame, which may be coated to increase the friction between both contacting parts. The endless chains (20) in each channel, with the shafts (19) of the disc groups (18), bear on and slide along the guides (29) joined to the frame (17).

The feed means (7) have means (31) (figures 6 and 17 to 19) transferring the products to be weighed from the feed means (7) to the buckets (8) which face the same during their travel in front of said feed means (see figure 1). The transfer means have means (32) lifting the products by transverse rows or alignments and means (33) temporarily retaining the rows, both means being synchronised and controlled by the programming and processing unit.

The lifting means comprise idle rollers (34) mounted between two side vertical plates and having a vertical rack (35) joined to said two side plates and to the stem (36) of the pneumatic cylinder (37) whose body is joined to a support (38) fixed to the frame (17) of the feed means (7) (figure 6). Lowering or raising of the rack (35) causes a pinion (39) mounted to rotate on the support (38) in either direction, which pinion meshes in turn with a rack (40) fixed to the retaining means (33), respectively causing them to be lifted or lowered, i.e.

lifting of the means (32) lifting the products causing the means (33) retaining the products to be lowered and vice versa. In order to ensure a correct displacement of the lifting means (32) and the retaining means (33), two vertical rods (41) are provided fixed at the bottom to the support (38) and crossed by two sleeves (42) with their respective inner friction bushes and joined to the retaining means (33), and by another pair of sleeves (43) like the above, albeit joined to the lifting means (32).

Figure 6 shows a channelling (C) arranged between the rear end of the chute (7a) and the top portion of the transfer means (32), which channelling comprises as many channels as there are channels in the feed means (7), and in line therewith and with the relevant units of the transfer means (31).

The feed means are conveniently provided with sidewalls, preferably diverging upwards to ensure the insertion and channelling of the products to be weighed as they travel along the channels of the means feeding such products, which walls are shown marked (P) on the top portion of figure 7. Brushes could also be used at the product inlet into such means to expedite their distribution in one layer.

The lifting means (32) only move or push one transverse row or alignment of products and block the next row, the products being channelled by transverse rows or alignments and longitudinal rows or alignments, each channel having one or more rows.

The guide means (lla) in each of the three lines of the linear conveyor means gradually bring the relevant buckets (8) face to face with the means (31) transferring the products to be weighed, and figure 1 shows such successive facing while the linear conveyor means travel around the cogwheel (14). Arrows are used to show the direction of travel of the pairs of side chains in each of the lines of the linear conveyor means.

The weighing station (9) (figure 22) is preceded in the direction of travel of the pairs of endless chains in each line of the linear conveyor means, by a station (44) stabilising the buckets, at which stabilisation station their supports are lowered and the buckets bear on and slide along the same to ensure an immediate subsequent weighing as accurately as possible, which lowering is achieved by means (not shown) guiding the supports of the buckets in each line, to be successively and directly borne at such stabilisation station and at the relevant weighing station (9).Figure (22) shows in phantom guide means (45) constituted as a sort of channel with a first short sector at some height relative to the bearing plane of the weighing station (9), followed by another short upward sector and a final sector which continues to rise in curved formation; the above in order to newly lift the buckets, drawing them away from the weighing station and causing them to turn around the cogwheel (15) (figures 22 and 1).

Following the path travelled by the three lines in the linear conveyor means, the buckets move in the direction of the arrows (figures 1 and 23), turning around cogwheel (16) and then rising up and turning around cogwheel (6), then travelling along the top portion of the weighing machine, at which sectors of the means guiding the buckets in each line are arranged which are controllable by the programming and processing unit and which may be temporarily diverted upwards relative to the adjoining rest of the guides of the guide means, to cause the buckets to be selectively tipped at the relevant stations (10) where the products contained therein are unloaded.

At the selective unloading stations (10) at issue (figures 1, 23 and particularly 24 since this is an enlarged detailed view thereof) sectors of the means guiding the buckets in each line are provided, each of the sectors having a pneumatic cylinder (46) whose stem is articulated to a plate (47) that is in turn articulated about the shaft (48) of a support fixed to the machine housing (1).

The plate (47) includes the relevant sector of the means guiding the buckets and a lower upwardly inclined plane towards the machine inlet, and thus when the cylinder stem (46) moves outwards, the plate (47) turns and said portion or sector of the means guiding the buckets is lifted causing said means to be halted and the buckets selected by the programming and processing unit to be tipped, the products contained therein dropping onto the relevant chute (49) prior to the braking effect of the respective flexible and elastic plate (50) which is articulated about the shaft (51) mounted on the machine housing (1) and bearing on an eccentric (51a) to adjust the inclination of the plate (50). When the stem of the pneumatic cylinder (46) is retracted, the plate (47) turns counter the previous direction, lowering and causing the guide means in such portion thereof to continue, as shown in figures 1, 23 and 24, said pneumatic cylinder being controlled at all times by the programming and processing unit. From such chute the products are led on the transverse conveyor means (11) (figures 1, 23 and 27).

Each transverse conveyor means (11) (figures 1, 23 and 27), being four in this example, comprises an endless belt (52) (figures 23 and 27) supported between two end rollers mounted on the machine housing (1), which endless belt is driven by one such roller with its shaft linked through a relevant transmission, in this case based upon trapezial belts and corresponding ribbed pulleys, to a gearmotor shaft (53), also fixed to the housing (1) and controlled by the programming and processing unit. Each endless belt (52) can be driven in either direction, each marked with arrows in figure 27. Flexible curtains may also be arranged next to the two possible outlet mouths of the products located on each endless belt.

At the end of the path travelled by the guide means on the top portion of the machine, sectors of such means are arranged for each line of buckets, causing the tipped buckets to subsequently return to their operative position, each such sector being constituted by a part (53) (figures 1 and 25) articulated about the shaft (54) of a support fixed to the machine housing (1), the lower end of said part having an upwardly inclined plane towards the rear of the machine, the guide means continuing along a downwardly curved channel shown in phantom in such figures. Above the part (53) there is a fixed part (55) whose bottom plane is in line with the top end of the curved channel shown in phantom.When a previously tippedbucket arrives at this portion of the machine, roller or slide bearing means therefor knock against the underside of the curved channel and lift the part (53), said bucket bearing means being led inside said curved channel, for the bucket to be guided in its normal operative position.

At the rear lower portion of the weighing machine lie the pairs of cogwheels (13) (figures 1 and 26) in each line of buckets of the linear conveyor means, the relevant side chain meshing with such wheel and the relevant means (lla) -some shown in phantom- guiding the buckets through top and bottom supporting means of each bucket being also shown. Means (56) for adjusting and tightening the chains in each line are also shown (figures 1, 2, 5 and 26).

Each of the buckets (8) in the weighing machine has supporting means fitted with temporary bearing and retaining means (57) (figures 20 and 21), the latter comprising horizontal side spigots (58) each housed within irregular-shaped slots (59) defined by salients on the bucket (8) that are hook-shaped (60) and bent at the bottom into an L shape, each of which leaves a lower open passage relative to the bucket body in order for it to be easily dismounted from the temporary bearing and retaining means (57), the salients allowing the spigots (58) to travel between the position shown in figure 21, where the bucket is borne in its normal operative position, and the lower position bearing on the lower horizontal wing of the respective salient (60) of the bucket (8); and the latter position is taken up by the bucket due to the actuation of the relevant guide means at the stabilisation (44) and weighing (9) stations, thereby for the correct weight of the full or empty bucket to be obtained (being its tare if empty).

The temporary bucket bearing and retaining means (57) have articulation means constituted in this example by two side sleeves (61) that are articulated about the transverse shaft (8a) (figures 2 to 5) crossing the sleeves (61) of the bucket means (57), namely three in this example, transversely aligned in the linear conveyor means of the weighing-machine. The two ends of each such shaft (8a) are joined to the relevant endless chain of the two chains with which the linear conveyor means is fitted.

Fixed to or forming part of the two sleeves (61) (the one on the left-hand side of figure 20 in this example) of the temporary bearing and retaining means (57), there is a side arm (62) provided with a hole for the passage of said transverse shaft, which arm is provided with roller bearing (or as appropriate slide bearing) means constituted by a top bearing or wheel (63) and by a bottom bearing or wheel (64). These bearings are supported on the respective sectors of the bucket- guide means and on those sectors in which only top guide means or bottom guide means are available.Each transverse shaft (8a) driving or articulating the buckets in each transverse alignment thereof has two sleeves (not shown) provided with recesses under the buckets, and thus at the stabilisation station (44) and at the weighing station (9) turning of each transverse shaft, together with the guide means, allows the means supporting each bucket to be lowered and the bucket to be directly supported on said stations, whereupon the bucket (8) and its supporting means (57), (58), (61), (62), (63) and (64) are linked with the respective bucket (8) through flexible thread-like means (65) arranged on either side of the bucket and operative while the buckets pass by said stabilisation and weighing stations, pulling the same, which flexible thread-like means are not operative during the rest of the travel of the buckets along the closed circuit made up by the linear conveyor means.

The arrangement of the bucket guide means (lea) is as follows, the guide means in which the top bearings (63) of the bucket support means act being designated top means, and the guide means of the bottom bearings (64) being designated bottom means.

The top guide means are arranged in the area of the stabilisation (44) and weighing (9) stations; the bottom guide means are arranged in the horizontal area located between cogwheels (15) and (16); top guide means are arranged in the area lying between cogwheels (16) and (6); top guide means are arranged in the area lying between cogwheels (4) and (12); top guide means are arranged in the area lying between cogwheels (12) and (13); bottom guide means are arranged between cogwheels (13) and (14); and top guide means and bottom guide means are suitably combined in areas where there are direction changes, so that the buckets always lie in their normal operative position.

The products not selected to be unloaded from the buckets remain therein for a new selection in the next cycle of the linear conveyor means.

An example of an automatic weighing machine fitted with the improvements subject of this invention includes three lines with 40 buckets or more per line, which is equivalent to 120 buckets or more, great speed being achieved in the obtention of batches of pre-set weight by the user, with little or no rejection.

This weighing machine can carry out what is known as "associative weighing" and/or "accumulative weighing" and thus in the latter the programming and processing unit holds the endless belt (52) 'of the relevant transverse conveyor means stopped, switching it on whenever a batch of product units with the weight pre-set by the user has accumulated thereon, to be unloaded onto a box or onto conveyor means outside the weighing machine.

Examples of possible operations with transverse conveyor means (11), considering the example described based upon four of such means, include the following: a) operation of three of the four endless belts feeding three alternatively located packaging machines, i.e.

located alternatively relative to each of the right and left-hand sides of the machine, with only one size and equal or different weights, the remaining endless belt being useful for an eventual return of products and to empty the weighing machine; b) operation of the weighing machine with two different sizes or two different products distributed among three of the four endless belts, for instance two of the endless belts working in the same direction and the third endless belt in the opposite direction or otherwise, the fourth endless belt being used for return and to empty the weighing machine; and c) operation of the weighing machine with three products, for instance differently coloured peppers to be supplied through three of the endless belts, the fourth endless belt being used for return and to empty the weighing machine.

The speed of the linear conveyor means should conveniently be constant, without stopping while the machine is operative, to avoid mechanical stresses on the buckets due to speed variations and stopping and starting of said linear conveyor means.

The weighing machine will optionally comprise laminar means (66) (figures 14 to 16) which may be placed in the operative position over the product feed means (7), said laminar means being controllable insofar as surface to be covered above the products and concealable in a non-operative position, displacement means (67) and guide means (68) being provided for such laminar means that may be constituted by one or several flexible sheets which may cover the channels of the feed means in whole or in part, being a single sheet or one per channel, or one for every two or more channels, and another one for one or more channels, figure 16 showing a specific embodiment with one sheet which may be placed over two channels and another one over the third channel.

Figure 14 shows the laminar means (66) in phantom thereby for the displacement means (67) and guide means (68) of said laminar means to be visible.

The displacement means (67) are constituted by an endless chain (69) (figure 15), a chain being arranged for each sheet, although depending upon the dimensions of the latter, two chains or more could be arranged, said endless chain being laid out between pinions (70), (71), (72), (73), (74) (the latter acting as a take-up) and (75), said pinions being mounted on a frame (76) joined to the frame (17) of the feed means (7).

Figure 16 shows how pinions (71) corresponding to the means displacing two laminar means (66) are driven jointly by a single transverse shaft (77) -although they could be driven by two independent shafts and therefore simultaneously or otherwise- the handle (78) being coupled at will to either of its ends, turning of which shall cause the laminar means (66) to move, covering the relevant part of the channels of the feed means, or uncovering the same, in which case said laminar means will retract towards the front of the feed means, i.e.

towards the inlet of the products into the same, moving towards and at the front vertical portion of the endless chains.

The means (68) guiding the laminar means (66) comprise a top section (79) to which end the laminar means have lower reinforcements to facilitate their sliding on such section, which in turn also serves as a guide for the relevant endless chain (70). The latter is also guided by a lower section (80), both sections being joined to the frame (17) of the feed means (7).

The laminar means (66) can assist in the obtention of a layer of products, fostering their movement in the feed means thereof at the weighing machine inlet.

The drive means described -pneumatic cylinders and electric motors- could be any other conventional ones, and activation thereof could be preferably pneumatic or hydraulic by conventional mechanical systems, as the case may be.

Claims (3)

1.- Improvements in automatic weighing machines for sundry and particularly food products, of the kind comprising a housing for the machine parts, means driving such parts, means feeding products at the machine inlet, conveying them along longitudinal channels and unloading them onto linear conveyor means, arranged in cyclic closed circuit and on longitudinal vertical planes, fitted with as many lines as there are channels at the feed means and lying coplanarly therewith to receive products from the.respective channels, each line in said linear conveyor means having a number of buckets in which the products to be weighed shall be laid, said buckets flowing through a station weighing the full or empty buckets and stations selectively unloading previously weighed products onto corresponding transverse conveyor means, moreover comprising a programming and processing unit which records the tare of each bucket and the true weight of the product or products collected by the bucket, linking means between said unit and the relevant machine parts, as well as general guide means for the linear conveyor means, and command, control and safety means therefor; characterised as follows: longitudinally and parallelly arranged taught elastic thread-like means inserted between the product feed means at the machine inlet; means transferring the products from the feed means at the machine inlet to the buckets, provided with means lifting such products by transverse rows or aYignments and means temporarily retaining such rows, both means being synchronised and controlled by the programming and processing unit; means guiding the lines in the linear conveyor means which make their respective buckets face the product transfer means; stations stabilising the buckets in the respective lines before they are weighed; means guiding the buckets in each line as they are lowered to be successively borne at the relevant stabilisation station and weighing station; sectors of the means guiding the buckets in each line, controllable by the programming and processing unit, which may be temporarily diverted relative to the adjoining rest of the guides, to bring about a selective tipping of the buckets at the relevant stations where the products contained therein are unloaded; sectors of the means guiding the buckets in each line, causing the tipped buckets to subsequently retrieve their operative position; means supporting , each bucket fitted with means temporarily bearing and retaining the same, cooperating with corresponding bucket means, and with articulation means about a transverse shaft joined to the linear conveyor means, said supporting means being moreover joined to a lateral arm fitted with roller or slide bearing means in the guide means of the linear conveyor means; flexible thread-like means pulling the budkets, operative as they pass by the relevant stabilisation and weighing stations, such thread-like means being respectively joined at their ends to the buckets and their relevant supporting means; means leading the previously weighed products unloaded from the buckets on the transverse conveyor means; and selective two-way drive for the means transversely conveying the previously weighed products, such means being controlled by the programming and processing unit.

2.- Improvements in automatic weighing machines for sundry and particularly food products, as in claim 1, characterised by comprising laminar means which may in the operative position be placed over the product feed means at the machine inlet, the surface to be covered above the products being controllable, said laminar means being concealable in the non-operative position and having means for moving and means for guiding the same.

3.- Any novel feature or combination of features disclosed herein.