Method and apparatus for adhesively joining a plurality of superimposed

Abstract

Adhesive joining system for joining a plurality of superimposed material layers. An elongated needle-like member is reciprocally and rotatably driven along and about its longitudinal axis so that each reciprocation causes the needle to pass through and be withdrawn from the superimposed layers. After the needle has passed through the layers, at least the outer tip is coated with an adhesive material. The adhesive material itself may be in solid, liquid or powdered form and be either heated or unheated. After coating, withdrawal of the needle from the material layers causes the adhesive on the needle to be deposited on the material through a wiping action caused by the pressure of the material exerted against the needle. Rotation of the needle-like member gathers loose fibers from the material layers and wraps them together in the adhesive to form a reinforced joint. Upon full retraction of the needle-like member from piercing contact with the material layers, the pierced area of the layers closes to fill the cavity with adhesive and squeeze it out into the surrounding material to further strenghten the joint. After each reciprocation, the layers may be conveniently advanced in order that a joined or bonded area may be formed along a desired path.