Abstract: An improved self-tightening pivotable gripper is provided in a gripper having two pin members and an elongated leaf spring, in which the pin members each have a jaw and pivot arm with a pivot portion therebetween and in which the spring bends around and joins the pin members at their respective pivot portions, so that the jaws and pivot arms are positioned in opposed pivotable relationship. The improvement includes providing one of the pivot arms with a backer wall therein to support a section of the spring which extends outwardly from the pivot portion and proximate the backer wall in the inside thereof and then bends to cross diagonally and inwardly toward the pivot zone of the two pin members and extends proximate the other of the arms in a diagonal spring span, so as to contact such other arm when an outward pressure of e.g. a clothesline, is applied to the spring span so that the pivot arms are pushed apart more tightly, closing the jaws more tightly on a load e.g. a towel.