Machine for manufacturing disposable cups
A machine for manufacturing disposable cups, including a side element, obtained from a blank of sheet material folded into a conical shape and sealed by a bottom element of circular shape, including a forming wheel rotatable with continuous motion. The forming wheel has a plurality of peripherally distributed forming assemblies including respectively a mandrel of tubular form carried by a support member swinging around an axis parallel to said axis of rotation of the forming wheel. First feeding means is adapted to orderly collect and insert single bottom elements into corresponding forming assemblies of the forming wheel. Second feeding means is adapted to collect single blanks in an orderly manner from a store in which the blanks are stacked and to transfer them in sequence, in an extended configuration, to the corresponding forming assemblies of said forming wheel.
1. A machine for manufacturing disposable cups, said disposable cups comprising a side element, obtained starting from a blank of sheet material folded into a conical shape, sealed by a bottom element of circular shape, said machine comprising
a forming wheel rotatable with continuous motion according to an axis of rotation and having, peripherally distributed thereon, a plurality of forming assemblies comprising respectively a mandrel of tubular shape having a profile corresponding to the cup to be made, said mandrel being held by a support member which may swing around an axis parallel to said axis of rotation of the forming wheel;
first feeding means adapted to orderly collect and insert single bottom elements into corresponding forming assemblies of said forming wheel;
second feeding means adapted to collect single blanks in an orderly manner from a store in which the blanks are stacked and to transfer them in sequence, in an extended configuration, to corresponding forming assemblies of said forming wheel;
folding means adapted to carry out tubular winding of said individual blanks on said mandrel of the respective forming assemblies;
welding means adapted to make, on said forming assemblies, individual items obtained by joining said blanks wound into tubular form with said corresponding bottom elements.
2. The machine of claim 1 , wherein said forming assemblies respectively comprise gripper means arranged in diametrically opposite positions with respect to said mandrel and operable independently from each other to hold said individual blanks wound into tubular form on the same mandrel.
3. A machine of claim 1 , further comprising a finishing wheel rotatable with continuous movement according to an axis of rotation parallel to said axis of rotation of the forming wheel and having a plurality of peripherally distributed containers associated with a respective support member, which may swing around an axis parallel to said axis of rotation of the finishing wheel, and adapted to receive respectively said cups from said forming wheel.
4. The machine of claim 1 , wherein said first feeding means comprises a shearing member capable of cutting in sequence said single bottoms from a reel of strip material; an annular shaped drawing die shaping an internal portion with a converging profile; a punch, coaxial to said shearing member, able to perform the drawing of said individual bottoms sheared from said reel of strip material at said die and the subsequent insertion of the drawn bottoms inside the mandrel of corresponding forming assemblies.
5. The machine of claim 1 , wherein said second feeding means comprises a wheel for gripping and transferring said blanks rotatable with continuous movement according to an axis of rotation parallel to said axis of rotation of the forming wheel and having, peripherally distributed thereon, a plurality of arms which may swing around a respective axis parallel to the axis of rotation of the same wheel, said arms having at the free end a respective gripping member capable of taking a single blank from said store and of transferring it to one said forming assembly of the forming wheel.
6. The machine of claim 5 , wherein said gripping member is angularly rotatable, around a respective axis of rotation, between a first position tangential to said wheel for gripping and transferring said blanks and a second position radial to the same wheel.
7. The machine of claim 1 , wherein said folding means comprises a pair of folding members consisting of shaped rollers rotatable on a support fixed externally to said forming wheel and rotatable in opposite directions, so as to progressively engage said blanks and bring them to adhere to the outer surface of said mandrel of the respective forming assemblies.
8. The machine of claim 1 , further comprising curling means adapted to fold the lower edge and the upper edge of said side element of the cups.
9. The machine of claim 1 , wherein said welding means is movable in a radial direction to said mandrel on said support member to carry out the welding of the opposite edges of said individual blanks wound into tubular form on the same mandrel.
10. A method for manufacturing disposable cups, comprising the steps of
a. rotating with continuous movement a forming wheel bearing a plurality of peripherally distributed forming assemblies respectively comprising a mandrel of tubular form having a profile corresponding to the cup to be made, carried by a support member swinging around an axis parallel to the axis of rotation of the forming wheel;
b. orderly taking single bottom elements by means of first feeding means and inserting them into corresponding forming assemblies of said forming wheel;
c. orderly taking single blanks by means of second feeding means from a store in which the blanks are stacked and transferring them in sequence, in an extended configuration, to the corresponding forming assemblies of said forming wheel;
d. carrying out the tubular winding of said individual blanks by folding means on said mandrel of the respective forming assemblies;
e. carrying out by welding means the mutual junction of opposite edges of said individual blanks wound into tubular form on said mandrel of the respective forming assemblies and the union of said individual blanks wound into tubular form to said corresponding bottom elements.