Fastener plunging apparatus

摘要

Apparatus is provided for plunging a fastener through a soft material preparatory to insertion of the fastener in a hard backing. The apparatus may be embodied as an attachment for a conventional fastener feed apparatus or as an improved form of feed apparatus itself. The improvement includes two telescoping members biased to a normal fully extended position. The members are engageable end-to-end with conventional telescoping elements of the feed apparatus and are axially movable with them. The force biasing the members apart is set so as to be substantially less than the force biasing the conventional elements to a fully extended position so that the fastener will be plunged through the soft material first upon application of a force, and then subsequently inserted into the backing upon application of additional force. Apparatus is provided for limiting the collapsed length of the members so as to control the depth of the plunge.