Abstract:
A device for continuously weighing articles in arrival from a conveyor organ, of a type comprising: a weighing device ( 40 ) arranged downstream of the conveyor organ ( 80 ), which weighing device ( 40 ) is able to detect a weight of articles transiting continuously thereon, a first conveyor ( 20 ) for abutting and engaging a side of an article (X) in arrival from the conveyor organ ( 80 ), which first conveyor ( 20 ) transfers the article (X) towards the weighing device ( 40 ); a second conveyor ( 30 ) associated to the weighing device ( 40 ) and arranged for receiving the article (X) while the article (X) is engaged to and drawn by the first conveyor ( 20 ) and being activatable so as to be able to convey the article (X) at a second advancement velocity (V 2 ) which is greater than the first advancement velocity (V 1 ), so as to disengage the article (X) from the action of the first conveyor ( 20 ) and to advance the article (X) freely onto the weighing device ( 40 ) in order to detect a relative weight thereof and convey the article (X) downstream of the weighing device ( 40 ).

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to equipment for weighing articles, in particular articles transiting on automated conveyor lines comprising several conveyor organs. The lines can be situated, for example, in plants for production, packing, labeling or any other type. 
         [0002]    A particularly important problem in these conveyor lines is how to introduce, downstream of a determined conveyor organ, a continuous weighing station for the articles, functionally integrated in the conveyor line downstream of the conveyor organ, which operates without there being any need to displace the articles from the line in which the weighing organs are not subject to interferences due to the conveyor organs present on the line downstream and/or upstream of the weighing station, in particular the vibrations to which these organs are subject. 
       DESCRIPTION OF THE PRIOR ART 
       [0003]    Document EP1715307A2 intends to obviate this problem by proposing an article conveyor system which comprises a plurality of conveyor belts operating at a same velocity, and having a same direction and same conveyor advancement sense. This system comprises two main closed ring-wound conveyor belts wound about pulleys having vertical axes with the belts facing one another and being counter-rotating, in order to horizontally advance an article, and a weighing station situated below the main conveyor belts. The weighing station in turn comprises a scales, a series of three closed ring-wound secondary conveyor belts (inlet, central and outlet) wound on pulleys having horizontal axes, contiguous to one another and arranged horizontally on a same plane such as to advance the article horizontally in a same direction as the two main conveyor belts. 
         [0004]    The secondary conveyor belts have, viewed overall, a dimension along the conveyor direction which is smaller than the dimension of the two main conveyor belts and are centrally arranged with respect thereto. At their longitudinal ends, the two internal branches of the main conveyor belts are distanced from one another such as to engage two opposite surfaces of an article, and to convey the article engaged in this way. 
         [0005]    At the horizontal inlet conveyor belt, the two internal branches of the main conveyor belts diverge as they are diverted towards the respective external branches thereof. In this way the main conveyor belts disengage the article which, therefore, comes to rest on the horizontal inlet belt. The horizontal inlet belt transfers the article onto the central belt, associated to the scales. In turn, the central belt transfers the article to the horizontal outlet belt, at which the two internal branches of the main conveyor belts converge towards one another with the aim of newly engaging the article in transit on the horizontal outlet belt. 
         [0006]    In this system, the scales determine the weight of the article while in transit on the central belt, i.e. when its weight is exerted on the central belt and thus on the scales associated thereto. The two second conveyor belts, inlet and outlet, are necessary for avoiding interference and vibrations during the weighing operation; furthermore, all the horizontal conveyor belts must operate in synchrony and the internal branches of the vertical belts must be moving at the same speed. 
         [0007]    The system of EP1715307A2 is constituted by a multiplicity of motorized components (the various conveyor belts) and is thus rather complex. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    The aim of the present invention is to provide a device for efficiently and continuously weighing the articles in arrival from a conveyor organ which is a part of a conveyor line, the device being functionally integratable in the line in which the weighing is not influenced by the conveyor organs arranged upstream and downstream of the device. 
         [0009]    A further aim of the invention consists in providing a device for efficiently and continuously weighing the articles in arrival from a conveyor organ which is a part of a conveyor line, which enables outlet of the already-weighed articles by means of the law of motion which regulates the movement of the articles along the conveyor organ upstream of the device. This is so that any further conveying subsequent to the weighing operating is independent of the velocity and/or the modes in which the articles are moved by the conveyor organ. 
         [0010]    The proposed device comprises: 
         [0011]    weighing means arranged downstream of the conveyor organ, which weighing means are able to detect a weight of articles transiting continuously thereon; 
         [0012]    first conveyor means for abutting and engaging a side of an article in arrival from the conveyor organ, which first conveyor means transfer the article, once the article has been engaged, and draw the said article along an advancement direction towards the weighing means, the first conveyor means being activatable such as to convey the article, once engaged, towards the weighing means along the advancement direction at a first advancing velocity; 
         [0013]    second conveyor means associated to the weighing means and arranged such as to be able to receive the article while the article is engaged to and drawn by the first conveyor means and the article is in advancement along the advancement direction towards the weighing means, the second conveyor means being activatable such as to be able to convey the article at a second advancement velocity which is greater than the first advancement velocity at which the article is advanced by the first conveyor means, such as to disengage the article from the action of the first conveyor means and to advance the article freely onto the weighing means in order to detect a relative weight thereof and convey the article downstream of the weighing means. 
         [0014]    It is obvious that during functioning of the device, thanks to the greater velocity at which the second conveyor means operate with respect to the first conveyor means, it is possible to disengage the article from the first conveyor means in order to engage it and move it via the second conveyor means to the weighing means. In this way, only the weight of the article bears down on the weighing means. Further, the second conveyor means are arranged contiguously but not contactingly downstream of the conveyor organ, such that the weighing operations are not subjected to interference and vibrations due to the conveyor line which comprises the conveyor organ. Thus the measuring operations of the weight of the article are particularly accurate. 
         [0015]    The first conveyor means of the device of the invention are configured such as to engage one side only of the articles. This enables the device to be more versatile. In a case in which the conveyor line is used to move articles having different dimensions (for example packing lines which can produce articles having different formats at different times), the first conveyor means of the device of the invention can advantageously comprise drawing elements, specially distanced from one another, for engaging a lateral surface of an article, through a wide range of formats. 
         [0016]    It is therefore advantageous that a device of the invention in which the first conveyor means comprise a conveyor belt and at least a drawing element borne by the belt and projecting there-from such as to engage a lateral surface of the articles to be conveyed. 
         [0017]    In the device of the invention, fixed planes are advantageously contiguously, preferably horizontally-arranged upstream and downstream of the second conveyor means, such as to limit the motorized components and further limit the vibrations. 
         [0018]    For the purposes of the weighing operations, it is preferable that the first conveyor means be associated to guide means, arranged upstream of the second conveyor means, for conveying the article drawn by the second conveyor means centrally with respect to the weighing means. 
         [0019]    In an advantageous embodiment of the proposed device, the second conveyor means comprise a closed ring-wound conveyor belt wound on pulleys having horizontal axes, activatable for receiving the articles from the first conveyor means and for drawing them towards the articles during the weighing operation. In this embodiment, the first conveyor means preferably comprise two conveyor belts, wound on pulleys with vertical axes, in which the internal branches are facing and moved in synchrony in the same direction as the branch of the upper branch of the conveyor belt of the second conveyor means, and provided with drawing elements which at the internal branches are correspondingly opposite. 
         [0020]    Alternatively, the first conveyor means can be constituted by a single conveyor belt, wound on pulleys having horizontal axes, arranged above the belt of the second conveyor means with a parallel transport direction to that of the second conveyor means. In this case one or more drawing elements of the first conveyor means, at the lower branch thereof, engage a side of the article and draw it horizontally in order to transfer it onto the second conveyor means. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    The characteristics of the invention will emerge from the following description of a preferred embodiment of the device, in agreement with what is set out in the claims and with the aid of the accompanying figures of the drawings, in which: 
           [0022]      FIGS. 1 and 3  are lateral views of an embodiment of the conveyor device of the invention at different functioning moments thereof; 
           [0023]      FIGS. 2 and 4  are views from above of the conveyor device shown respectively in  FIGS. 1 and 3 ; 
           [0024]      FIGS. 5A-5B  and  6 A- 6 B are lateral views of detail K of the conveyor device of the invention in successive moments; 
           [0025]      FIGS. 5C-5D  and  6 C- 6 D are views from above of the detail K respective of  FIGS. 5A-5B  and  6 A- 6 B. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    In the various  FIGS. 1-6D , identical components have been denoted using the same numerical references in the following description of the various embodiments of the invention, and they will have similar characteristics unless otherwise indicated. 
         [0027]    The figures illustrate an embodiment of the device  1  of the invention, functionally integrated downstream of a conveyor organ  80  internally of a conveyor line which conveys a series of articles X. These articles are singly denoted by Xn, in which n increases from downstream to upstream in the line, i.e. in reverse order with respect to the advancement direction WW of the articles X. 
         [0028]    In the illustrated embodiment, with the aim of having a horizontal advancement direction of the articles X, the two conveyor belts  200 ,  200 ′ of the first conveyor means  20  are wound on pulleys  250 ,  250 ′ having vertical axes and the conveyor belt  300  of the second conveyor means  30  is wound on pulleys  350  having horizontal axes. 
         [0029]    The device of  FIGS. 1-4  advantageously comprises a fixed inlet plane  50 , arranged between the conveyor organ  80  and the second conveyor means  30  and contiguous to both thereof, in order to receive the articles X to be weighed coming from the conveyor organ  80 . The fixed inlet plane  50  is thus also upstream of the weighing means  40  associated to the second conveyor means  30 . In this embodiment, the first conveyor means  20  have a development which is such as to be able to abut and engage a side of an article X to be weighed (denoted in  FIGS. 1-2  by X 2 ) received from the fixed inlet plane  50 , and to transfer the article X from the fixed inlet plane  50  to the second conveyor means  30 . 
         [0030]    The conveyor belt  300  of the second conveyor means  30  preferably has an upper branch  360  which is positioned at a height that is not greater than the fixed inlet plane  50 , and more preferably is lower by 1 mm than the fixed inlet plane  50 . This facilitates conveying of the articles X from the fixed inlet plane  50  to the upper branch  360  of the conveyor belt  300  of the second conveyor means  30  and limits the impacts on the weighing means  40  associated to the second conveyor means  30 . 
         [0031]    It is therefore advantageous to include, as shown in  FIGS. 1-6D , a fixed outlet plane  60 , arranged downstream of the second conveyor means  30  and contiguous thereto, in order to receive the weighed articles X coming from the second conveyor means  30 . In this case the first conveyor means  20  exhibit a development which is such as to abut and engage a side of the article X, already weighed and transferred by the first conveyor means  20  onto the fixed outlet plane  60 , and to transfer the article X from the fixed outlet plane  60 , and to transfer the article X from the fixed outlet plane  60  downstream thereof, for example on a further conveyor device arranged downstream of the second conveyor means  30 . 
         [0032]    The device of the invention advantageously comprises third conveyor means  90  arranged contiguously downstream of the fixed outlet plane  60  in order to receive the articles X transferred by the first conveyor means  20  downstream of the fixed outlet plane  60  in order to continue the movement along the conveyor line towards specific work stations. In this way it is possible to further move the article X along the conveyor line, in which the device of the invention is integrated, independently of the velocity and the mode of advancement of the conveyor organ  80  downstream of the device  1 . 
         [0033]    In the preferred embodiment ( FIGS. 1-4 ), the two conveyor belts  200 ,  200 ′, are identical to one another and exhibit the relative internal branches opposite one another; the belts bear relative drawing elements  70 ,  70 ′ which are opposite at the internal branches; it follows that the upstream side of the article X 2  is engaged by two corresponding drawing elements  70 ,  70 ′ in order to transfer the article onto the second conveyor means  30 . 
         [0034]    The conveyor belts  200 ,  200 ′ exhibit a development such that an article X to be weighed (denoted as X 2  in  FIGS. 1-2 ), once received on the fixed inlet plane  50 , can be abutted and engaged by a side of the drawing elements  70 ,  70 ′. Further the development must be such that the article X, once weighed and received on the fixed outlet plane  60  (as shown in  FIGS. 5A and 5C ), can be newly abutted by a side of the drawing elements  70 ,  70 ′ (see  FIGS. 5B and 5D ) for subsequent transfer downstream of the fixed outlet plane  60 . 
         [0035]    In order to prevent interference on the weighing operations, there is preferably an interstice of at least one millimeter between the internal branches of the vertical conveyor belts  200 ,  200 ′ and the surfaces of the article X facing them. 
         [0036]    For the purposes of the weighing operations, it is preferable that guide means (not illustrated) are associated to the first conveyor means  20 , which guide means are associated upstream of the second conveyor means  30  such as to convey the article X drawn by the second conveyor means  30  centrally with respect to the weighing means  40 . 
         [0037]    As illustrated in  FIGS. 1-4 , the fixed inlet plane  50  comprises an admittance device  130  of known type, preferably vertically mobile, as in  FIGS. 1-8 , for regulating intermittent access to the fixed inlet plane  50  of the articles X coming from the conveyor organ  80 . 
         [0038]    In  FIGS. 1-4  the conveyor organ  80  upstream of the device  1 , and thus of the inlet plane  50 , is illustrated by way of example as a conveyor belt  800  wound on pulleys  850  having horizontal axes. 
         [0039]    In  FIGS. 1-2 , the admittance device  130  is in a halted position, i.e. it projects from the fixed inlet plane  50  and abuts the article X 3  at the side of the article X 3  which is downstream with respect to the advancement direction. Consequently the article X 3  and the following articles X 4  are halted on the terminal part of the conveyor organ  80 . The admittance device  130 , being synchronizable with the first conveyor means  20 , can enable infeed of an article X 2  onto the first fixed inlet plane  50  in phase relation with the movement of the first conveyor means  20 . This enables the drawing elements  70 ,  70 ′ to abut and engage the article X 2  at the side of the article X 2  which is upstream with respect to the advancement direction while the article X 2  is on the fixed inlet plane  50 . Once engaged, the article X 2  is drawn by the first conveyor means  20  along the advancement direction WW towards the weighing means  40 . 
         [0040]    In  FIGS. 3 and 4 , the article X 2  has already been restingly received on the conveyor belt  300  of the second conveyor means  30  which convey it at an advancement velocity V 2  which is greater than the velocity it was previously moved at on the first conveyor means  20  such that it was disengaged from the first conveyor means  20 . The drawing elements  70 ,  70 ′ do not abut the article X 2  again, which can therefore advance freely on the weighing means  40 , which measure its weight. 
         [0041]    The conveyor belt  300  will then transfer the article X 2 , once weighed, downstream of the weighing means  40  on the fixed outlet plane  60 . 
         [0042]    As illustrated in  FIGS. 5A and 5C , the article X 2  briefly rests on the fixed outlet plane  60  until the drawing elements  70 ,  70 ′ intercept it, newly abutting it at its upstream side with respect to the advancement direction (see  FIGS. 5B and 5D ), then to transfer it downstream such that it can be engaged by third conveyor means  90  located downstream of the fixed outlet plane  60 . 
         [0043]    At this point the admittance device  130  will be switched into the consent position and will no longer project from the fixed inlet plane  50 . Thus the article X 3 , no longer halted by the admittance device  130 , can be pushed by the convey or organ  80  which will transfer it onto the fixed inlet plane  50 , as shown in  FIGS. 3 and 4 . 
         [0044]    The third conveyor means  90  comprise a conveyor belt  900 , wound on horizontal-axis pulleys, which bears a plurality of drawing teeth  970 , equidistanced from one another. In  FIGS. 6A ,  6 C the drawing elements  70 ,  70 ′ have just transferred the article X 2  onto the upper branch of the conveyor belt  900 ; this is facilitated by the fact that the conveyor belt  900  is stationary. 
         [0045]    In phase relation with the above, the belt  900  is activated, which causes the intercepting of a drawing tooth  970  against the upstream side of the article X 2 . In phase relation, as illustrated in  FIGS. 6B-6D , the drawing elements  70 ,  70 ′, having reached the end of their run, disengage from the article X 2  and the third conveyor means  90  draw the article X 2  by one step in the advancement direction WW. 
         [0046]    It is particularly advantageous to use articulated drawing elements  70 ,  70 ′ such as the ones shown in  FIGS. 9A-10D . The drawing elements  70 ,  70 ′ comprise a tooth  110  and a rod  120 , the tooth  110  being rotatably constrained to the conveyor belt  200 ,  200 ′ such that a first end thereof projects from the conveyor belt  200 ,  200 ′ in order to abut, engage and draw the articles X, and with the rod rotatably constrained by an end thereof to the conveyor belt  200 ,  200 ′, in an upstream position to the tooth, considering the advancement direction of the conveyor belt  200 ,  200 ′, and by another end thereof being rotatably constrained to the second end of the tooth  110  such that the tooth  110 , in the winding tract of the conveyor belt  200 ,  200 ′ about the pulleys  250 ,  250 ′, is forced to undergo a rotation about the constraint point  150  thereof with the belt  200 ,  200 ′ in order to reduce the size thereof, as illustrated in  FIG. 6D . 
         [0047]    This embodiment is particularly advantageous when it is necessary to convey the article X further on the line, for example with the third conveyor means  90  arranged downstream of the fixed outlet plane  60  and synchronizable with the first conveyor means  20 . It is possible to set a phase relation between the first conveyor means  20  and the third conveyor means  90  such that the teeth  110  of the first conveyor means  20  and the drawing tooth  970  are vertically aligned as shown in  FIGS. 10A and 10B  and can thus abut and convey the article X downstream of the fixed outlet plane  60  with a law of motion that is independent of the velocity and mode with which the article X is conveyed upstream of the fixed inlet plane  50 . 
         [0048]    In the illustrated example it is hypothesized that the third conveyor means  90  will have a step motion; it is however possible that the third conveyor means  90  might also be continuously activated. In this case the articles X are transferred by the teeth  110  onto a fixed support, for example the fixed outlet plane  60 , having an appropriate length, or onto a further fixed plane aligned thereof at the same height thereas, from which they are collected by a drawing tooth  970 . 
         [0049]    The above has been described purely by way of non-limiting example, and any variants of a practical-applicational nature are understood to fall within the ambit of protection of the invention as described herein above and as claimed in the following.