Abstract:
A device for feeding layers of products to a palletizing plant, containing an accumulation surface arranged to receive lines of products transferred from a conveyor positioned in front of it by a pusher which acts in a direction perpendicular to the conveyor axis and parallel to the axis of the accumulation surface; the device including at least two parallel, coplanar conveyors of different type positioned in front of the accumulation surface and associated with the pusher supported by an upper structure in such a manner as to be free to move vertically and free to move in the direction of the axis of the accumulation surface.

Description:
FIELD OF THE INVENTION 
     The present invention relates to feed devices or palletizing plants. 
     BACKGROUND OF THE INVENTION 
     Known palletizing plants enable stacks of goods of one and the same type to be formed into layers, each layer being formed from several adjacent stacks of the same product. The layer forming device varies in known plants depending on the type of product to be palletized. Hence if the type of product varies, the type of layer forming device also has to be changed. This represents a limit in current plants in that to change the feed device in those palletizing plants in which this is possible, the plant has to be halted for a certain time with a resultant loss of production. 
     SUMMARY OF THE INVENTION 
     The object of the present is to overcome the aforesaid drawbacks by providing a layer-forming device able to operate on at least two different types of product, for example bottles and boxes. The feed device of the invention comprises at least two parallel, coplanar lines arranged side-by-side to form at least one row of different products on each of them. The lines are positioned in front of a moving accumulation surface, such as a conveyor belt, on which the layers of products are formed. Each of said at least two lines can be fed with a certain type of product by a usual conveyor means positioned upstream of it. 
     The present invention comprises a movable pusher able to transfer that portion of the product row facing said moving accumulation surface from one of said at least two row-forming lines to said surface. There are also provided means to form layers from rows of products of one and the same type and means for compacting said layers. According to the present invention the movable pusher is suspended from an upper guide and is free to move in a vertical direction. It is also provided with means for interacting with two different types of product. 
     In order to clarify the operational and constructional characteristics of the invention a preferred embodiment thereof is described hereinafter by way of a non-limiting example and illustrated on the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partly sectional side view of the device of the present invention. 
     FIG. 2 is a plan view of FIG.  1 . 
     FIG. 3 is an enlarged view of FIG.  1 . 
     FIG. 4 is an enlarged view of FIG.  2 . 
     FIG. 5 is a section on the plane V—V of FIG.  1 . 
     FIG. 6 is an enlarged view of one of the components of the invention. 
     FIG. 7 is an enlarged view or a second component of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The figures show a device  1  for feeding alternatively boxes  2  or bottles  3 , or similar products. The device  1  comprises an external frame  4  having two equal bases  40  each provided with four adjustable identical feet  41 . A vertical upright member  42  extends from each of the bases  40 . At their top, the two uprights  42  support two equal longitudinal, parallel opposing structural sections  43 . The vertical upright member  42  also support two projecting brackets  44  supporting the product row-forming means, described hereinafter. The means supported by the projecting brackets  44  comprise, in succession, a first conveyor  5  having a movable conveying member for the boxes  2 , a boxlike member  6  the upper surface of which is coplanar with the upper branch of the conveyor  5 , and a second conveyor  7  for conveying the bottles  3 . 
     Specifically, the movable member of the conveyor  5  consists of a motorized roller table  50  formed from a succession of rollers  500 . It should be noted that the distance between two successive rollers  500  is such as to allow passage of a movable wall  501 , the purpose of which is to maintain two successive boxes  2  spaced apart by a few centimeters in order to improve their manoeuvrability during layer formation. 
     In contrast, the conveyor  7  comprises two chains  70  with parallel space-apart slats which pass endlessly about end wheels, not shown, and driven by a geared motor of known type. 
     To the side of the conveyor  7  there is provided a frame  8  for supporting a third belt conveyor  9  the travel direction of which is perpendicular to that of the conveyors  5  and  7 , and of which the upper branch defines the forming surface for the layers which are then fed to the palletizing plant. The upper branch of the conveyor  9  is coplanar with the upper branches of the conveyors  5  and  7 . The conveyor  9  is driven by a geared motor  90 , shown in FIG.  1 . 
     The frame  8  also supports two inverted U-shaped frames  10  and  11 , each of which centrally supports a cylinder-piston unit  12 , to the rod  120  of which there is fixed a plate  121  which supports a transverse bar  13  parallel to the advancement plane of the conveyor  9  and which, when in its lowered position, defines the front end of a layer. 
     The frame  8  is also provided with equal and opposite devices  14  and  15  for laterally compacting the layer of products to be palletized. 
     Each of said equal devices  14  and  15  is fixed to the frame  8  by means of two identical brackets  16 . 
     More specifically, each bracket  16  supports a sleeve  17  of horizontal axis for guiding a rod  18 , to that end overlying the belt of which there is fixed a plate (not shown) supporting two equal and parallel superposed bars  19  for compacting the layer. The bars  19  can be moved horizontally, at least one of them being hinged to the rod of the double-acting cylinder-piston unit  20 , which is fixed to the frame  8  by a third bracket, not shown. 
     When a row of products has been formed on the conveyor  5  or on the conveyor  7 , this row is transferred onto the conveyor belt  9  by the pusher  21  supported by the motorized carriage  22  which slides via wheels  23  on suitable guides  230  supported by the structural sections  43 . 
     The pusher  21  can also be moved vertically by two equal vertical rods  24  provided with a rack, in each of which there engages the pinion  25  connected to the shaft  26  of a usual geared motor  27 . As an alternative, not shown, the pusher  21  is guided by two vertical rods and raised by two flat belts, each passing about a drum. 
     The pusher  21  comprises a frame  210 , to the upper side of which the two rods  24  are fixed by known means, and which on its underside supports nine equal vertical rods  28  arranged in three parallel rows  29 ,  30  and  31 . The rods  28  of the row  29  are joined together by two transverse parallel bars  32  positioned on the same side of the rods, whereas the rods  28  of the row  30  are joined together by two pairs of transverse parallel bars  33  and  34  positioned on both sides of the rods. Finally, with reference to FIG. 6, the row  31  of rods  28  supports a pair of superposed parallel bars  35  on the left side in FIG. 6, and a single bar  36  of greater thickness on the right side. 
     This latter bar  36  is used by the invention to urge the row of boxes formed on the conveyor  5  onto the conveyor belt  9 . With reference to FIGS. 1 and 3 the boxes are fed to the conveyor  5  by a rearward-positioned usual conveyor  60  having a travel speed less than the travel speed of the conveyor  5  in order to space the boxes ( 2 ) apart when they arrive at conveyor  5 , in order, if desired, to enable the boxes to be rotated through 90° by a usual pneumatic positioner. The number of boxes rotated depends on their size and shape and on the dimensions of the pallet surface. This rotation is necessary to construct a layer of adjacent boxes formed from the greatest possible number of boxes compatible with tile pallet surface area. 
     It should be noted that in proximity to that edge of the conveyor  60  in contact with the conveyor  5  there is provided a counter device  62  which counts the number of objects transiting. The counter device  62  is entirely usual and can be formed from photoelectric cells or similar means. 
     In contrast, bottles are fed to the slat conveyor  7  by a rearward-positioned conveyor  63  which is entirely similar to the conveyor  7  itself. At that edge adjacent to the edge of the conveyor  7 , the conveyor  63  includes a counter device  64  which counts the bottles fed to the conveyor  7 . The counter device  64  is entirely similar to the aforedescribed counter device  62 . 
     All the plant drive and mover means are controlled by a microprocessor programmed to provide the following operation. Assuming boxes are to be palletized, the bottle conveyor  7  will be empty and not in operation, neither will its rearward-positioned conveyor  63 . 
     The operator keys into the microprocessor the dimensions of the boxes to be palletized and the dimensions of the pallet surface. The processor determines the number of boxes to form each layer and any required rotation of one or more boxes in a given row by the pneumatic positioner  61 . 
     The boxes of each row are separated from each other by the transverse movable walls  501 , each of which is moved vertically by an underlying cylinder-piston unit  502  to separate the boxes  2  from each other so that they offer no hindrance when being brought into mutual contact on the belt  9 . 
     When a row of boxes  2  has been formed of a number depending on the box dimensions, the pusher  21  is positioned to the left of said row as shown by dashed lines in FIG. 3, and pushes the boxes onto the conveyor belt  9 , which by advancing carries them against the transverse bar  13 . The process is repeated a number of times equal to the number of box rows which are to form a layer. 
     When the layer is complete the devices  14  and  15  laterally compact the layer, after which the bar  13  rises to enable the belt  9  to carry the layer formed of boxes to the accumulation surface stage of the palletizing plant. The process is repeated identically for each layer. 
     If layers of bottles are to be formed, the belts  5  and  60  are not used. 
     In this case the product  63  and product  7  form two rows of bottles. When both the rows are complete the pusher  21  pushes them onto the conveyor belt  9 , where it is raised and returned to the position shown in FIG.  3 . 
     The advancing belt  9  carries the two parallel rows against the transverse bar  13 . 
     When the layer is complete the bar  13  is raised and the conveyor carries the layer of bottles formed as described to the next stage of the palletizing plant, and the layer forming process is repeated identically. 
     The plant shows two bars  13  for stoppage on the belt  9 , to enable a layer of objects to pause upstream of the stacking operations.