| 摘要 |
The invention relates to an impact-drive fastener 1 comprising a twisted wire body, a substantially solid common axial core 2, a protruding helix 3 extending from a pointed leading end and a trailing elongate driving shank 4 of reduced radial diameter. The protruding helix comprises a plurality of loosely wound thread-cutting blade-like helical projections 5 extending radially from the core and inclined at an angle (8 figure 2a) of less than 42{ to the longitudinal axis (9 figure 2a) of the core. The reduced diameter driving shank has a twisted and grooved surface (34 figure 4a) that carries no such swept angle thread-culling blades. The driving shank is preferably arranged to fit into and cooperate with a driving adapter (21 figure 8) having a hollow leading end (24 figure 8) for insertion into a host material. The driving adaptor is unyielding and is arranged for transmitting axial force from an impact-energy driving machine to the driving shank of the profiled fastener. One embodiment relates to a method of connecting a plurality of layers of a structure using a helically profiled fastener using an adapter having a solid tail shaft end, a reduced diameter hollow nose end and a shoulder positioned between said tail and nose ends. Further embodiments relate to an unyielding drive adapter for transmitting axial force from an impact-energy driving machine to a driving shank of a helical profiled fastener and an impact drive fastening assembly comprising said helically profiled fastener and said unyielding drive adapter. Said drive adaptor having: ```a driven shaft tail end (22) having means to engage the impact-energy driving 20 machine; ```a leading nose end (24) having an elongate hollow axial recess that is dimensioned to receive and cooperate with the reduced diameter driving shank of the helical profiled fastener; ```a shoulder portion (23) positioned between the tail and nose ends; and wherein the outer periphery of the leading nose end (24) includes an abrasive part (29) or cutting formation (29) that is arranged to abrade or cut a host material. |
