Attachment member unit to be driven into hard receiving material by powder charge operated setting tool

摘要

Attachment member unit includes an axially extending shank (1) with a load engagement part (2) at its trailing end. The shank has a pointed tip (3) at its leading end. A prestressing element (4) laterally encloses the pointed tip (3). The prestressing element is formed of a sleeve part (4a) and a bearing part (4b). The bearing part forms the leading end of the prestressing element and the sleeve part forms its trailing end. A recess (4c) extends into the bearing part from the leading end. The recess (4c) has a diameter such that the trailing end portion of the prestressing element under deforming forces can telescope into the bearing part. When the attachment member unit is driven, the prestressing element (4) causes a prestress against a connector member (7) and due to the telescoping action and also a dampening action, the connector member can be fastened to a receiving material (8) by the shank (1), and the connecting member is not damaged.