Patent Publication Number: US-2022234841-A1

Title: Motorized transfer apparatus for conveyors of bulk objects

Description:
This application claims the benefit of Italian Patent Application No. 102021000001676 filed on Jan. 28, 2021, the disclosure of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention generally relates to conveyors of bulk objects and, in particular, a motorized transfer apparatus for conveyors of bulk objects. 
     BACKGROUND 
     As is known, a conveyor of bulk objects defines a moving plane for generic objects to be transported. Such a conveyor is generally of the closed or endless loop type and can consist, for example, of a belt, a plurality of interconnected rollers or a belt with articulated links. 
     Transferring objects between pairs of conveyors arranged in sequence, or from a conveyor to a machine, can be a problem when small objects are transported on large conveyors. Conveyors, in fact, especially if they are large, are equipped with pulleys or end rollers of particularly large diameter to allow the belt, the interconnected rollers or the belt with articulated links to deviate their movement from the forward path to the return path of the respective closed loop. Small objects, therefore, could fall into the gap that inevitably lies at the adjacent ends of pairs of conveyors arranged in sequence. 
     There are several technical solutions to this problem, such as static transfer plates, idle rollers transfer plates and the use of return guide devices called “nose bars”. Each of these technical solutions, however, has both undoubted advantages and also potential deficiencies. 
     Static transfer plates, for example, are extremely inexpensive and help reduce the space between pairs of conveyors arranged in sequence, but do not keep objects moving during their transfer. Idle roller transfer plates, while less economical than static transfer plates, can keep objects moving during their transfer, but slow them down considerably. The return guide devices (“nose bars”) make it possible to considerably approach the adjacent ends of pairs of conveyors arranged in sequence, but they cannot be applied on conveyors which are not suitable for operation with pulleys or small diameter end rollers, especially when these are conveyors with interconnected rollers or articulated links. 
     Motorized transfer apparatuses have, therefore, been manufactured which, when interposed between the adjacent ends of pairs of conveyors arranged in sequence, allow the transported objects, even if small, not only not to fall from the conveyors, but also to be easily transferred from one conveyor to another while maintaining their transfer speed constant. These motorized transfer apparatuses are usually small in size and are provided with a respective conveyor belt, or a closed loop belt with articulated links. The conveyor belt, or the belt with articulated links, is rotated by means of pulleys or motorized actuator gears which are usually inside the motorized transfer apparatus. 
     Document DE 20 2010 006549 U1 discloses a motorized transfer apparatus according to the preamble of claim  1 . Another motorized transfer apparatus according to the prior art is disclosed in document EP 2000425 A1. 
     In the event that the motorized transfer apparatus is equipped with a belt with articulated links, an expansion and, therefore, an undesired elongation of this belt with articulated links with respect to the project dimensions is likely to occur in operating conditions. This elongation may be due to the most varied factors, such as the material (usually of a polymeric nature) the links are made with, the temperature variations, the weight of the transported objects, the type of support of these objects on the belt with articulated links, etc. If the elongation of the belt with articulated links is excessive, the actuator gears may no longer perform their function of moving this belt correctly, which belt would therefore be subject to “jumps” and unwanted speed variations. 
     A possible technical solution to the elongation problem may be to equip the motorized transfer apparatus, internally, with tensioning rollers of the belt with articulated links. However, considering the small size of the motorized transfer apparatus, the presence of these rollers could cause technical problems, or excessively increase the size of the apparatus itself and/or the related costs. 
     SUMMARY 
     The object of the present invention is, therefore, to provide a motorized transfer apparatus for conveyors of bulk objects which is capable of solving the aforementioned drawbacks of the prior art in an extremely simple, economical and particularly functional way. 
     In detail, it is an object of the present invention to provide a motorized transfer apparatus for conveyors of bulk objects, in particular provided with a belt with articulated links, which allows to limit the dilatations and/or elongations of its own belt without the need to use internal tensioning rollers. 
     Another object of the present invention is to provide a motorized transfer apparatus for conveyors of bulk objects, in particular provided with a belt with articulated links, which is particularly compact and of smaller size than similar apparatuses according to the prior art. 
     These objects according to the present invention will be achieved by providing a motorized transfer apparatus for conveyors of bulk objects. Further characteristics of the invention are highlighted by the dependent claims, which are an integral part of the present description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The characteristics and advantages of a motorized transfer apparatus for conveyors of bulk objects according to the present invention will be clearer from the following exemplifying and hence non-limiting description, referring to the attached schematic drawings in which: 
         FIG. 1  is a bottom perspective view of a preferred embodiment of the motorized transfer apparatus for conveyors of bulk objects according to the present invention, on which only a part of the respective belt with articulated links is mounted; and 
         FIG. 2  is an exploded view of the internal components of the motorized transfer apparatus of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     With reference to the figures, a preferred embodiment of the motorized transfer apparatus for conveyors of bulk objects according to the present invention is shown. The motorized transfer apparatus is indicated as a whole with reference number  10 . 
     The motorized transfer apparatus  10  comprises, in a per se known manner, a conveyor belt  12  movable along a predetermined feeding direction A. The conveyor belt  12  is of the type comprising a plurality of modular elements  14  arranged in sequence and articulated with one another to form a closed loop conveyor belt  12  with articulated links having a predetermined overall length. 
     The motorized transfer apparatus  10  further comprises a support structure  16  which, in turn, comprise at least one sliding surface  18  for the closed loop conveyor belt  12  with articulated links. As shown in the Figures, the sliding surface  18  has a substantially cross-sectional triangular shape, that is, a section which is parallel with respect to the feeding direction A of the conveyor belt  12 , so as to form in sequence:
         a first flat portion  20  of the sliding surface, which is substantially horizontal in the operating configuration of the motorized transfer apparatus  10  and which defines a transport plane for the objects transported by said conveyor belt  12 ,   a second flat portion  22  of the sliding surface, which is inclined downward in the operating configuration of the motorized transfer apparatus  10  and defines a descent path for the conveyor belt  12 , and   a third flat portion  24  of the sliding surface, which connects the second flat portion  22  of the sliding surface with the first flat portion  20  of the sliding surface and defines an ascent path for the conveyor belt  12 .       

     The motorized transfer apparatus  10  also comprises at least one motorized actuator device  26  for the conveyor belt  12 , such as an electric motor, and at least one drive unit  32 ,  34 , inserted inside said support structure  16  and designed to transmit the motion generated by the motorized actuator device  26  to the conveyor belt  12 . In particular, the drive unit  32 ,  34  comprises a plurality of drive gears  32 , which engage in a per se known manner with each modular element  14  of the conveyor belt  12 , and at least one drive shaft  34 . The drive shaft  34 , again in a per se known manner, can be provided with one or more retaining rings  40  of the Seeger type, so as not to oscillate axially inside the support structure  16 , and one or more rolling bearings  42 . 
     Advantageously, each modular element  14  of the conveyor belt  12  has a length L, measured along the feeding direction A of the conveyor belt  12  itself, which is between about 1.5% and about 6% of the overall length of the conveyor belt  12 , preferably between about 2% and about 6% of the overall length of the conveyor belt  12 . It has in fact been observed that in conveyor belts with articulated modules or links, any elongation of the conveyor belt itself must not exceed the length, or pitch, of a single module or link. Otherwise, in fact, each drive gear would no longer perform its function correctly and possible “jumps” of the conveyor belt could occur. 
     Preferably, between the first flat portion  20  of the sliding surface and the second flat portion  22  of the sliding surface, as well as between the third flat portion  24  of the sliding surface and the first flat portion  20  of the sliding surface, respective rounded upper connecting portions  28 ,  30  are provided, which are smooth and have a cross-sectional arc profile. Again preferably, these rounded upper connecting portions  28 ,  30  have a very small diameter, equal to about 6 mm, but in any case sufficient to make the modular elements  14  of the conveyor belt  12  slide easily along the triangular sliding surface  18 . 
     Between the second flat portion  22  of the sliding surface and the third flat portion  24  of the sliding surface a further rounded lower connecting portion  38 , smooth and having a cross-sectional arc profile can be provided. This rounded lower connecting portion  38  has, however, a diameter which is greater than the diameter of the rounded upper connecting portions  28 ,  30 , since a plurality of drive gears  32  of the drive unit  32 ,  34  protrudes from this rounded lower connecting portion  38  to engage with the modular elements  14  of the conveyor belt  12 . The rounded upper connecting portions  28 ,  30 , instead, do not require drive gears, since their relatively small diameter does not generate excessive friction towards the modular elements  14  of the conveyor belt  12  which, therefore, slides freely and without “jumps” on these rounded upper connecting portions  28 ,  30 . 
     In a preferred embodiment of the motorized transfer apparatus  10 , the overall length of the conveyor belt  12  is between about 133 mm and about 400 mm. In detail, also taking into account the aforementioned specific dimensions of the rounded upper connecting portions  28 ,  30  of the sliding surface  18 , each modular element  14  preferably has a length L of about 8 mm, whereas the conveyor belt  12  comprises twenty-eight interconnected modular elements  14 , so that the overall length of this closed loop conveyor belt  12  is equal to about  224 . Again according to this preferred embodiment of the motorized transfer apparatus  10 , the first flat portion  20  of the sliding surface has a length, measured along the feeding direction A of the conveyor belt  12 , which is comprised between about 70 mm and about 150 mm. 
     As shown in  FIG. 2 , the support structure  16  can be of the modular type. In other words, the support structure  16  can comprise two or more modules  16 A- 16 D aligned and interconnected along an interconnection direction D which is substantially perpendicular to the feeding direction A of the conveyor belt  12 . The modules  16 A- 16 D can be reciprocally joined by at least one screw  36  oriented along the aforementioned interconnection direction D. 
     In detail, for reasons of compactness of the support structure  16 , at least one module  16 A at least partially encloses the motorized actuator device  26 , whereas one or more modules  16 B- 16 D can at least partially enclose the drive gears  32  and the drive shaft  34  of said drive unit  32 ,  34 . However, it is possible that the motorized actuator device can also be housed outside the support structure  16 . 
     It has thus been seen that the motorized transfer apparatus for conveyors of bulk objects according to the present invention achieves the purposes previously highlighted. 
     The motorized transfer apparatus for conveyors of bulk objects of the present invention thus conceived is however susceptible of numerous modifications and variations, all of which falling within the same inventive concept; furthermore, all the details can be replaced by technically equivalent elements. In practice, the materials used, as well as the shapes and dimensions, may be any according to the technical requirements. The scope of protection of the invention is therefore defined by the attached claims.