Pencil of which the rubber collar part is attached by ultrasonic welding and specially adapted collar part

摘要

A lead pencil (8) with a rubber (6) mounted on its end in a ferrule (18) fixed to the body of the pencil has the outer body (7) and the ferrule (18) made of compatible thermoplastic materials. The base of the ferrule (21) is fixed to the end of the pencil by localised inter-penetration of the thermoplastic materials on at least one zone of ultrasonic melding.