Abstract:
A selection apparatus for grouping articles in predetermined quantities from a moving stream of articles. The apparatus includes a horizontal rotating plate with three equally spaced arms and a lug assembly attached to an end of each arm. The plate rotates at a repeating velocity pattern enabling a lug assembly to be inserted between articles from the moving stream and a group of selected articles to be separated by a predetermined acceleration of the lug assembly.

Description:
This is a continuation of international application No. PCT/US02/39630, filed Dec. 11, 2002, which is hereby incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   This invention relates, in general, to control of article position prior to packaging articles, and is more particularly concerned with separating groups of predetermined quantities of the articles from a continuous stream of articles. 
   U.S. Pat. No. 5,979,147 to Reuteler concerns a bottle grouping assembly and method for a packaging machine. The apparatus comprises a pair of rotatable selector wheel assemblies that rotate at constant velocity between which a double stream of bottles moves. The bottles are directed to the rotatable selector wheel assemblies and a finger attached to each rotatable selector wheel, engages a selected bottle and accelerates the bottle to a machine speed that is greater than the in-feed speed. 
   U.S. Pat. No. 5,718,323 to Flix illustrates a device for spacing products having carriages, each of which is capable of moving independently of the other carriages. Each carriage includes a grasping element for grasping products, individually or by lots, and a drive part for pulling the carriage on a guide rail. The grasping element and the drive part of each carriage are controlled by an electronic control box which enables spacing desired between two consecutive products to be achieved. 
   Both these references and the prior art refer to means for positioning or separating articles from the stream of articles and generally seek to address common problems associated with achieving consistency in the positioning or number of articles separated from the stream of articles. The present invention addresses the difficulties associated with providing versatility of operation from a single apparatus for separating articles from a stream of articles. 
   SUMMARY OF THE INVENTION 
   One aspect of the present invention provides apparatus for separating articles or for creating groups of articles in a moving stream of such articles. The apparatus comprises a rotatable body, at least one lug assembly carried by the rotatable body and a lug. The lug is movable away from the axis of rotation of the body into an operative position and thereafter is to retract during rotation of the body. The apparatus further includes means for rotating the body with a pre-determined cyclic variation such that the lug can engage between a pair of articles in the stream substantially at the velocity of the stream and thereafter at increased velocity to separate an article or articles downstream of the stream of articles from the other articles in the stream. 
   Preferably, the lug may be maintained in a substantially perpendicular arrangement relative to the article stream to improve its introduction between adjacent articles. 
   According to an optional feature of this aspect of the present invention the lug may be cam activated for movement into and away from the stream of articles. 
   According to another optional feature of this aspect of the present invention the lug assembly may be attached to a fixed arm of the rotating body. 
   According to a further optional feature of this aspect of the present invention the lug assembly may include a lug element coupled to a lug body via a lug shaft. The lug body may contain sliding means which contact the lug shaft, which supports at least one biasing means. 
   According to yet another optional feature of this aspect of the present invention there may be a single variable speed continuous belt to which the lug or lugs may be attached. 
   In one class of embodiments, the apparatus may further comprise a control means which operates the rotating body at the rotational velocity with the pre-determined cyclical variation. 
   Preferably, the control means may comprise means for receiving information regarding the speed of cartons in the feed path. 
   More preferably the control means may comprise a manual input means. Alternatively, the control means may comprise a sensor arranged to measure the speed of cartons in the feed path. 
   The apparatus may have a sensor arranged to measure the speed of the lug or lugs. 
   According to a further optional feature of this aspect of the present invention, the control means may vary the speed of the lug or lugs to lie within the range plus or minus 1–30% of the speed of the articles traversing the feed stream. 
   A second aspect of the present invention provides a method for separating articles or for creating groups of articles in a moving stream of such article. The method includes moving a lug assembly carried by a rotatable body away from the axis of rotation of the body into an operative position, and thereafter to retract during rotation of the body. The method further includes controlling the rotation of the body with a pre-determined cyclic variation such that the lug can engage between a pair of articles in the stream substantially at the velocity of the stream and thereafter, at increased velocity, separate an article or articles downstream from the other articles in the stream. 
   Preferably, the pre-determined cyclical variation is determined with reference to the size of an article, the velocity of the article, and a quantity of articles to be separated from the row of articles. 
   Preferably, the speed of an article in the stream may be received by a control means which controls the article separating apparatus. More preferably, the speed of the articles is sensed automatically. 
   According to an optional feature of this aspect of the present invention, the speed of each lug may be varied by the control means to lie within the range plus or minus 1–30% of the speed of the articles traversing the stream. 
   Advantageously, the present invention provides a system which mitigates problems, such as system down-time, that occur when constant velocity rotating selection systems are required to perform a modified task, such as, selecting a different quantity of articles, or accounting for an altered in-feed or out-feed speed. 
   The present invention is generally applicable to controlling the position of articles in the proximity of the selection apparatus and, whilst being particularly applicable to grouping articles from a moving stream of articles prior to packaging, may be employed more widely. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Exemplary embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: 
       FIG. 1  is an illustration of a selection apparatus (viewed from below and to one side) constituting a first embodiment of the present invention; 
       FIG. 2  shows an illustration of the selection apparatus of  FIG. 1  after a first operation period; 
       FIG. 2   a  is a graph showing velocity of a lug of the selection apparatus with the first operation period indicated; 
       FIG. 3  shows an illustration of the selection apparatus of  FIG. 1  after a second operation period; 
       FIG. 3   a  is a graph showing velocity of the lug of the selection apparatus with the second operation period indicated; 
       FIG. 4  shows an illustration of the selection apparatus of  FIG. 1  towards the end of a third operation period; 
       FIG. 4   a  is a graph showing velocity of the lug of the selection apparatus with the third operation period indicated; and 
       FIG. 5  is an illustration of a selection apparatus (viewed from above and to one side) constituting a second embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  illustrates a selection apparatus  10  comprising a rotatable plate  14  which has a plurality of radially extending arms. In this embodiment there are three arms  15   a ,  15   b ,  15   c  that are equally spaced apart about the circumference of the plate. An underside of an outermost end of each arm pivotally interfaces with a lug assembly  16   a ,  16   b ,  16   c . Located on a topside of the outermost end of each arm is a device means which, in this embodiment, is provided by a belt guide  33  around which an endless belt  32  is fed. The belt  32  is also fed around at least one idler  34  which is mounted on a central body of the rotatable plate  14 . The rotatable plate  14  is pivotally mounted on the lowermost end of a central shaft  12 . 
   Each of the three lug assemblies  16   a ,  16   b ,  16   c  identically comprises a wedge-shaped lug element  26  connected to a lug body  20  via a lug shaft  24 . Each lug assembly  16   a ,  16   b ,  16   c  is oriented such that lug element  26  points in the same direction. With reference to the lug assembly  16   a,  as illustrated on  FIG. 1 , a protrusion  27   a  from a near-face of the lug shaft  24  is coupled to a first end of a horizontally positioned pin  28   a . Similarly, a protrusion  27   b  from a far-face of the lug shaft  24  is coupled to a first end of a pin  28   b . A middle section of the pins  28   a ,  28   b  is spring loaded along a side of the lug body  20  by means of suitable resilient biasing means. For example, a coil spring  30   a  surrounds the pin  28   a,  and is secured at the first end of the pin  28   a  and also to the lug body  20 . A second end of both pins  28   a  and  28   b  protrudes from a back face  22  of the lug body  20 . A cam follower  21  is attached to an uppermost face of the lug shaft  24 . Each of the lug assemblies  16   a ,  16   b ,  16   c  is constantly orientated with the lug element  26  protruding towards, and normally to, a stream of bottles, or other articles conveyed along a platform  36  ( FIG. 2 ). 
   A mechanical cam  18  is situated in close proximity to the rotatable plate  14 . Furthermore, the mechanical cam  18  is situated at approximately the same vertical level as the rotatable plate  14  such that the cam follower  21  of each lug assembly  16     1 ,    16   b,    16   c  sequentially engages with a cam track  19  in the underside of the mechanical cam  18  as the plate  14  rotates. 
   In operation, a motor assembly (not illustrated) drives the rotatable plate  14  via the central shaft  12  in direction “X”, i.e., clockwise, as viewed above in  FIG. 2 . As each arm of the rotatable plate  14  moves towards a far end of the mechanical cam  18 , the cam follower  21  engages with the far end of the cam track  19 . Thus, each lug assembly  16   a ,  16   b ,  16   c , in turn, is guided through the cam track  19 . The selection apparatus (including the mechanical cam  18 ) is situated alongside an article path  36  such that a straight middle section  17  of the cam track  19  runs parallel and closest to the article path  36 . With reference to  FIG. 2 , articles on the associated article path  36  move from left to right. The lug element  26  is shaped so that it may be urged smoothly between articles or between selected groups of articles. 
   In operation, movement of the lug element  26 , relative to the lug body  20  and perpendicular to the article path, is against the spring loading of the springs  30   a ,  30   b . When the lug shaft  24  is urged from a rest position (caused by the cam follower  21  moving through cam track  19 ), the springs  30   a ,  30   b  are deformed and a slidable means located within the lug body  20  enables the shaft to move smoothly out of the body. 
     FIGS. 2 ,  3  and  4  show a plan view of the selection apparatus  10  of the present invention and an article path  36  guiding a stream of bottles A from the left-hand side to the right-hand side of each figure. The in-feed stream of bottles is moving at an approximately constant velocity. Specifically,  FIGS. 2 and 3  show the lug assembly  16   a  of selection apparatus  10  at the end of a first and second operation period respectively, and  FIG. 4  shows the lug assembly  16   a  towards the end of a third operation period. 
     FIGS. 2   a ,  3   a  and  4   a  are graphs showing the velocity of the lug assembly  16   a , indicating the first, second and third operation periods B, C, D, respectively. During the first operation period, the velocity component parallel to the article path  36  of the lug assembly  16   a,  is substantially similar to the velocity of the stream of bottles A. Therefore, the lug element  26  of the lug assembly  16   a  may be urged between two bottles (as shown in  FIG. 2 ) with minimal disturbance to the stream of bottles A. 
   During the second operation period, the velocity component parallel to the article path  36  of the lug assembly  16   a  comprises two aspects. Initially, the lug assembly  16   a  accelerates to a velocity greater than the in-feed velocity of the stream of bottles and subsequently maintains that greater velocity briefly. As illustrated in  FIG. 3 , bottles in the article stream to the right-hand side of the lug element  26  are thereby separated from the article stream which continues to advance at a lower velocity. 
   During the third operation period shown in  FIG. 4 , the velocity component parallel to the article path  36  of the lug assembly  16   a  comprises three aspects. The lug assembly  16   a  accelerates gradually, then rapidly accelerates to its peak velocity, and then rapidly decelerates to the in-feed velocity of the stream of bottles. Thus, initially, the lug assembly  16   a  is removed from contact with the bottles and the rapid acceleration is required to move the second lug assembly  16   b  to the start of the first operation period due to the cyclical nature of the rotational velocity of selection assembly  10 . In the present embodiment, each operation period lasts approximately 0.3 seconds. It will be apparent to the skilled man that  FIG. 4  illustrates the position of the lug assembly  16   a  approximately 0.9 seconds after the first operation period began. 
     FIG. 5  illustrates a second embodiment of a selection apparatus  110 . The reference numerals utilized generally indicate like components to the reference numerals of  FIG. 1  except that the reference numerals are preceded by a “1”. Only certain differences between the first and second embodiments will be hereinafter described. A rotating plate  114  of the second embodiment of the selection apparatus  110  has two (as opposed to three in the first embodiment) arms  115   a,    115   b  spaced at 180 degrees. An underside of an outermost end of each arm  115   a,    115   b  pivotally interfaces with a lug assembly  116   a ,  116   b  which is modified as compared to the lug assemblies  16   a ,  16   b ,  16   c  of  FIG. 1 . Specifically, a pin  128   a  (and a pin  128   b  not illustrated) has a stop at both ends and a lug shaft  124  is shorter than the lug shaft  24  of  FIG. 1 . 
   A part of a suitable bearing structure  140  is attached to an upper end of a central shaft  112  to a support the selection apparatus  110 . Positioned above the part of the bearing structure,  140 , but with a control connection to the central shaft  112 , is a motor assembly  137 ,  138 . 
   In operation, the lug assemblies  116   a ,  116   b  of the selection apparatus  110  will be subject to velocity changes similar to the velocity changes experienced by the lug assemblies  16   a ,  16   b ,  16   c  in the first embodiment of the present invention. Clearly, modifications will be necessary. For example, the velocity peak of the third operation period will be altered in order that the lug assembly  116   a ,  116   b  can be moved into position at the start of the cam track (not shown) once the other lug assembly  116   b ,  116   a  has reached the end of the cam track. 
   Importantly, the operation of both the first and second above described embodiments are generally controlled by a microprocessor,  135 . It is not usually necessary for the microprocessor,  135  to be situated within the selection apparatus  10 ,  110 . Instead, the microprocessor  135  is located away from the selection apparatus  10 ,  110  and has a control connection  136  to the motor assembly  137 ,  138 . Specifically, the rotational velocity of the rotatable plate  14 ,  114  during the first, second and third operation periods, is determined by control data from the microprocessor 135 , which is input to the motor assembly  138 . Advantageously, the control data may be varied by a user of the selection apparatus  10 ,  110  in order to enable various modes of apparatus operation. For example, it is envisaged that numerous velocity patterns during the first, second and third operation periods may be utilized. Also, a seamless transition between differing velocity patterns may be realized in order to accommodate a change in the in-feed velocity of articles on the article path, in the size or type of articles, in the spacing between in-feed articles, or in the article grouping ultimately required. 
   Changes to the control data may be initiated either by a user inputting information concerning the articles into the microprocessor or, alternatively, by an article sensing means positioned at the article in-feed path which could send data to the microprocessor. The data from the article sensing means  140  may include details of article size and weight, gaps between articles, or other irregularities which may occur. 
   It is envisaged that the present invention may be made commercially available as an integral part of a system for selecting and packaging as well as separately supplied on a retrofit basis. 
   It will be appreciated that the above description has been given by way of example only and that modifications in detail may be made within the scope of the invention. For example, the slidable means within lug body  20  may be any suitable mechanism to allow the lug shaft  24  to move smoothly back and forth, such as a system of rollers. Also, the springs  30   a ,  30   b ,  130   a ,  130   b  located in the lug assemblies  16   a ,  16   b ,  16   c ,  116   a ,  116   b  may be replaced by any suitable biasing means. As will be recognized by those skilled in the art, the invention may also be realized with one arm, or four or more arms. 
   It will be understood that selection apparatus of different sizes may be required depending upon how they are deployed, and similarly, motor assemblies of different powers may be required dependant upon the size of the selection apparatus and the weight of the articles.