Cross web layer application device

An application device for applying layers of material in spaced relationship generally transversely across an elongate longitudinally moving web having first and second parallel edges and opposite major surfaces, said device comprising:

• a frame;
• means on said frame for defining a through path for the web including means for defining
• an inlet path portion along which inlet path portion the edges of the web move generally in imaginary parallel planes disposed at right angles to the surfaces of the web, which inlet path portion terminates at a terminal end,
• an outlet path portion along which outlet path portion the edges of the web move generally in imaginary parallel planes parallel to and spaced from said planes in which generally move the edges of the web along the inlet path portion, said spacing being in a direction normal to the edges of the web along which outlet path portion begins at a beginning end adjacent said terminal end, and
• a transverse path portion between said terminal and beginning ends of the inlet and outlet path portion;
• means on said frame for periodically moving said means for defining the transverse path portion so that a portion of the web along the transverse path portion moves generally edgewise in a direction parallel to said planes while the individual lengths of the inlet and outlet path portions are simultaneously changed, which movement of said means for defining the transverse path portion is between a first position at which the inlet path portion has its minimum length and a second position at which the inlet path portion has its maximum length;
• and
• applying means on said frame for applying a layer of material generally transversely across a portion of the web along the transverse path portion during movement of said means for defining the transverse path portion from each first position to said second position;
• so that when the web is moved lengthwise at a predetermined speed in a first direction along said inlet and outlet path portions and said means for defining the transverse path portion is moved from said first position to said second position at said predetermined speed the longitudinal movement of the portion of the web along the transverse path portion is essentially stopped, and the later of material can be applied transversely across the portion of the web along the transverse path portion by said applying means;
• said applying means comprising:
• a vacuum applicator wheel having a generally cylindrical periphery and having an axis at right angles to said planes, said wheel being rotatably mounted on said frame for rotation about said axis;
• a platen having a planar support surface supporting one surface of the web along said transverse path portion and being carried by said means for reciprocating said guide members, said wheel and support surface being sized and positioned so that said support surface will move along a path tangential to the cylindrical periphery of said vacuum applicator wheel during movement of said means for reciprocating said guide members from said first position to said second position;
• means for moving said cylindrical periphery of said vacuum applicator wheel generally in synchronism with said support surface during movement of said means for reciprocating said guide members to afford application of the layer of material by said applicator wheel transversely across the portion of the web between said support surface and said applicator wheel;
• means for defining a path for supply length of strip material leading to the periphery of said vacuum wheel comprising a first drum rotatably mounted on said frame and having a periphery defining a portion of the path and adapted to be contacted by and to guide the second surface of the supply length of strip material, and a second cooled drum rotatably mounted on said frame and having a periphery defining a portion of the path between said first drum and said vacuum drum;
• pressure sensitive hot melt adhesive applying means on said frame along the periphery of said first drum for applying a strip of melted pressure sensitive hot melt adhesive to the first surface of the supply length of strip material carried along the path by the periphery of said first drum;
• the periphery of said second cooled drum being adapted to be contacted by and to cool and guide the pressure sensitive hot melt adhesive coating along the first surface of the supply length of strip material;
• means for rotating said first and second drums to provide a rate of speed at the peripheral surface of the second cooled drum that is greater than the rate of speed at the peripheral surface of the first drum so that the supply length of strip material is longitudinally stretched between said first and second drums;
• means for advancing the supply length of strip material along the path from said second drum to said vacuum wheel at a rate of speed slower than the speed of the peripheral surface of said vacuum wheel;
• and
• means for cutting a predetermined length from the supply length of strip material along the peripheral surface of the vacuum wheel so that the cut length of adhesive coated strip material will be carried into engagement with the portion of the web along the transverse path portion.