Apparatus and method for applying an elongated tab to a moving substrate

Apparatus for applying a thermoplastic-adhesive-impregnated, elongated, flexible member to a moving web, comprising:

• (a) means for raising the temperature of the impregnating adhesive to a level at which it will satisfactorily bond the member to the web, said temperature raising means comprising:
• (i) a first roll having an outer peripheral surface and an axis about which said first roll rotates;
• (ii) a second roll having an outer peripheral surface and an axis about which said second roll rotates, said second roll being at least partially axially coextensive with said first roll, and said axis of said second roll being disposed for pivoting in a plane generally parallel to said axis of said first roll;
• and
• (iii) means for heating at least one of said rolls;
• (iv) wherein the flexible member is coiled successively about said first and second rolls with each of said coils extending about both of said rolls;
• so that, as said second roll is pivoted so that its axis moves in said plane so that said axes define an increasingly sized angle in said plane, adjacent of said coils will become increasingly spaced from one another in order to prevent inadvertent engagement and bonding thereof;
• and
• (b) means for directing the flexible member, after being coiled about said rolls, into engagement with the moving web.

Apparatus for applying and bonding a string coated with a thermoplastic adhesive to a moving substrate, comprising:

• (a) a first roll having a longitudinal axis and being disposed for rotation about said axis;
• (b) a second roll having a longitudinal axis and being disposed for rotation about said axis of said second roll, said second roll being at least partially axially coextensive with said first roll and pivotable about a point so its axis defines a plane generally parallel to said axis of said first roll;
• (c) a casting encircling an axial portion of at least one of said first and second rolls, said casting having a plurality of heating elements embedded therein;
• (d) a third roll having a longitudinal axis and being disposed for rotation about said axis, the axis of said third roll being generally parallel to the axis of said first roll and having an outer peripheral surface frictionally engaged by the moving substrate to define a nip therebetween;
• and
• (e) means for transmitting rotational motion of said third roll to said first roll;
• (f) wherein the string is coiled successively about said first and second rolls a sufficient number of times to absorb heat from said roll, so that, as said second roll is pivoted so that the angle between said axes in said plane is increased in size, adjacent coils of the string passing about said rolls are spaced axially along said rolls so that they do not engage one another, said roll having an axial portion of which said casting encircles, in order to raise the temperature of the adhesive to a level at which satisfactory bonding of the string to the substrate will occur, and wherein, thereafter, the string is directed into said nip and into engagement with the substrate.

A method of extending the period of time during which an elongated flexible member coated with a thermoplastic adhesive is in engagement with a heating roll, comprising the steps of:

• (a) providing a second roll having an axis spaced from the axis of the heating roll;
• (b) successively coiling the flexible member about both rolls;
• and
• (c) spacing said coils axially along said rolls so that they do not engage one another by pivoting said second roll with its axis moving in a plane generally parallel to said axis of said heating roll to a position at which said axes are out of parallel alignment so that the angle between said axes in said plane is increased in size.