Patent Publication Number: US-2023159196-A1

Title: Wrapping machine with a rotary platform

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is related to Italian patent application No. 102020000004228 filed on Feb. 28, 2020, the entire disclosure of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The invention relates to a wrapping machine with a rotary platform. 
     In particular, the invention relates to a wrapping machine to wrap products with at least one band of wrapping material. 
     BACKGROUND ART 
     When dealing with the wrapping of products in wrapping material bands, a wrapping machine is known, which comprises a base; a rotary platform, which defines a support surface for at least one product and is mounted on the base so as to rotate around a rotation axis, which is substantially vertical and perpendicular to the support surface; and a plurality of support rollers, which are interposed between the base and the rotary platform and are distributed around the aforesaid rotation axis. 
     The wrapping machine further comprises a guide upright, which projects upwards from the base and extends in a vertical direction, which is substantially parallel to the rotation axis of the rotary platform; and a support slide, which is configured to receive and hold a spool of wrapping material and is movable along the guide upright so as to wrap the wrapping material band in a spiral around the products combining the movements of the rotary platform around the rotation axis and the movements of the support slide along the guide upright. 
     Since the guide upright is fixed and the rotation speed of the platform cannot exceed a threshold value set by safety standards in force, known wrapping machines of the type described above have a relatively long operating cycle, during which each product is wrapped in the relative wrapping material band, and, as a consequence, a reduced productivity. 
     DISCLOSURE OF INVENTION 
     The object of the invention is to provide a wrapping machine with a rotary platform, which does not suffer from the drawbacks discussed above and can be actuated in a straightforward, relatively low-cost manner. 
     According to the invention there is provided a wrapping machine with a rotary platform according to the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described with reference to the accompanying drawings showing a non-limiting embodiment thereof, wherein: 
         FIG.  1    is a schematic perspective view, with parts removed for greater clarity, of a preferred embodiment of the wrapping machine according to the invention; 
         FIG.  2    is a schematic perspective view, with parts removed for greater clarity, of a detail of the wrapping machine of  FIG.  1   ; 
         FIG.  3    is a schematic perspective view, with parts removed for greater clarity, of a detail of  FIG.  2   ; 
         FIG.  4    is a schematic perspective view, with parts removed for greater clarity, of a detail of  FIG.  3   ; 
         FIG.  5    is a schematic perspective view, with parts removed for greater clarity, of a detail of  FIG.  4   ; and 
         FIG.  6    is a schematic sectional view, with parts removed for greater clarity, of a detail of the wrapping machine of  FIG.  1   . 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     With reference to  FIGS.  1  to  6   , number  1  indicates, as a whole, a wrapping machine to wrap products  2  in a band  3  of wrapping material, in this specific case a stretch film. 
     The wrapping machine  1  comprises a substantially flat base  4  comprising, in turn, a substantially circular plate  5  and a substantially rectangular board  6 , which are connected to one another. 
     The wrapping machine  1  further comprises a rotary platform  7 , which has a circular shape, defines a substantially horizontal support surface P for at least one product  2  and is mounted above the plate  5  so as to rotate, relative to the base  4 , around a rotation axis  8 , which is substantially parallel to a vertical direction  9 . 
     The wrapping machine  1  further has a feeding disc  10 , which is mounted between the plate  5  and the platform  7  coaxially to the axis  8  and radially projects from the platform  7 . 
     The disc  10  is coupled to the base  4  in a rotary manner through the interposition of a plurality of centring wheels  11  ( FIGS.  5  and  6   ), which are uniformly distributed around the axis  8  and along a lower annular flange  10   a  of the disc  10 , project upwards from the plate  5  and are mounted so as to rotate around respective rotation axes  12 , which are parallel to one another and to the direction  9 . 
     The wrapping machine  1  further comprises two roller cages  13 ,  14 , the cage  13  being mounted between the plate  5  and the disc  10  and the cage  14  being mounted between the disc  10  and the platform  7 . 
     The cage  13  comprises an annular support plate  15  ( FIG.  5   ), which is mounted coaxially to the axis  8  and is coupled to the base  4  in a rotary manner through the interposition of a plurality of centring wheels  16 , which are uniformly distributed around the axis  8  and along an inner peripheral edge of the plate  15 , project upwards from the plate  5  and are mounted so as to rotate around respective rotation axes  17 , which are parallel to one another and to the direction  9 . 
     The cage  13  is further provided with a plurality of rollers  18 , which are mounted through the plate  15 , are distributed around the axis  8  and are coupled to the plate  15  in a rotary manner so as to rotate, relative to the plate  15 , around respective rotation axes  19 , which are substantially radial and transverse to the axis  8 . 
     The rollers  18  have a diameter which is substantially equal to a distance between the plate  5  and the disc  10 , measured parallel to the direction  9 , so that they are in contact both with the plate  5  and with the disc  10 . 
     The cage  14  comprises an annular support plate  20  ( FIGS.  2  and  3   ), which is mounted coaxially to the axis  8  and is coupled to the base  4  in a rotary manner through the interposition of a plurality of centring wheels  21 , which are uniformly distributed around the axis  8  and along an inner peripheral edge of the plate  20 , project downwards from the platform  7  and are mounted so as to rotate around respective rotation axes  22 , which are parallel to one another and to the direction  9 . 
     The cage  14  is further provided with a plurality of rollers  23 , which are mounted through the plate  20 , are distributed around the axis  8  and are coupled to the plate  20  in a rotary manner so as to rotate, relative to the plate  20 , around respective rotation axes  24 , which are substantially radial and transverse to the axis  8 . 
     The rollers  23  have a diameter which is substantially equal to a distance between the disc  10  and the platform  7 , measured parallel to the direction  9 , so that they are in contact both with the disc  10  and with the platform  7 . 
     The disc  10  and the platform  7  are moved around the axis  8 , with rotation directions that are contrary to one another, by an operating assembly  25  comprising an electric motor  26 , which is fixed to the board  6  and has an output shaft, which is provided with a gear (not shown) coupled to a crown wheel  27  ( FIGS.  3  and  4   ), which is obtained along an outer peripheral edge of the disc  10 . 
     The assembly  25  further comprises a transmission device  28  to transmit the rotation motion of the disc  10  to the platform  7 . 
     The device  28  comprises a crown wheel  29  ( FIGS.  2 ,  3  and  4   ) obtained along an inner peripheral edge of the disc  10 ; a crown wheel  30  ( FIG.  2   ), which is obtained on a lower annular flange  7   a  of the platform  7  and extends into the crown wheel  29 ; and a plurality of gears  31  ( FIGS.  2 - 5   ), which are interposed between the crown wheel  29  and the crown wheel  30 , project upwards from the plate  5  and are mounted so as to rotate around respective rotation axes  32 , which are parallel to one another and to the direction  9 . 
     With regard to what explained above, it should be pointed out that, when the disc  10  is moved by the motor  26  around the axis  8  with a given rotation direction, the platform  7  is moved by the gears  31  around the axis  8  with a rotation direction that is contrary to the one of the disc  10 . 
     The disc  10  supports a gantry  33  comprising two vertical uprights  34 , which extend upwards from the disc  10  in the direction  9 , are diametrically opposite one another relative to the axis  8  and carry, connected to their free ends, a horizontal cross member  35 , which is transverse to the uprights  34 . 
     One of the uprights  34  supports a bracket  36 , which is coupled to the upright  34  in a sliding manner and is configured to receive and hold a spool  37  of band  3 . 
     The bracket  36  is movable along the relative upright  34  in the direction  9  so as to wrap the band  3  in a spiral around the product  2  combining the movements of the platform  7  and of the gantry  33  around the axis  8  with the movements of the bracket  36  and, hence, of the spool  37  in the direction  9 . 
     The bracket  36  is moved along the relative upright  34  in the direction  9  by an operating assembly  38  comprising an electric motor  39 , which is fixed to the board  6  and has an output shaft, which is provided with a gear (not shown) coupled to a crown wheel  40 , which is obtained along an outer peripheral edge of a transmission ring  41  ( FIGS.  1  and  2   ). 
     The ring  41  is mounted coaxially to the axis  8  and is coupled to the disc  10  in a rotary manner through the interposition of a plurality of pairs of centring wheels  42  ( FIGS.  1  and  2   ), which are mounted on the disc  10  and are distributed around the axis  8 . 
     The ring  41  is further provided with a crown wheel  43  ( FIGS.  1  and  2   ) obtained along an inner peripheral edge of its and defines part of a transmission device  44 , which is designed to connect the motor  39  and the bracket  36  to one another. 
     The device  44  further comprises a transmission screw  45 , which is coupled in a rotary manner to the disc  10  and to the relative upright  34 , so as to rotate, relative to the gantry  33 , around a rotation axis  46  parallel to the axis  8 , and is further coupled to the bracket  36  through a screw-nut screw coupling. 
     The screw  45  is provided with a gear  47  ( FIGS.  1  and  2   ), which is splined on a lower end of the screw  45  and is coupled to the crown wheel  43 . 
     The wrapping machine  1  finally comprises an electronic control unit  48 , which is configured to selectively control the motors  26  and  39  in such a way that: 
     when the disc  10  and the ring  41  have the same rotation speed around the axis  8 , the assembly consisting of the gear  47 , the screw  45  and the bracket  36  is still; and when the disc  10  and the ring  41  have respective rotation speeds around the axis  8  which are different from one another, the gear  47  and the screw  45  are moved around the axis  46  and the bracket  36  is moved along the screw  45  in the direction  9 . 
     The wrapping machine  1  offers some advantages, which are mainly due to the fact that, by combining the movements of the platform  7  and of the gantry  33  around the axis  8  with respective rotation directions that are contrary to one another, the wrapping machine  1  has a relatively short operating cycle, during which each product  2  is wrapped in the relative band  3 , and, as a consequence a relatively high productivity. 
     Furthermore, the wrapping machine  1  offers a further advantage lying in the fact that the electric motor  39  operating the bracket  36  is fixed to the board  6  of the base  4  and the transmission device  44  is mechanical, hence it does not require the use of electrical power supply cables and/or of power supply batteries and/or of electrical sliding contacts.