Patent ID: 7377019
Filing Date: 2008-05-27
Classification: B25B,F16B,Y10T

Abstract:
1. A method of attaching a first relatively soft structural member made of a hard wood to a second underlying relatively hard structural member made of a high tensile strength steel, said method comprising the steps of: (a) providing a plastic strip and a plurality of screw fasteners mounted in said plastic strip, said plastic strip comprising a longitudinally-extending straight series of evenly spaced holes with each hole having a plurality of inwardly facing circumferentially-spaced ribs, and each of said screw fasteners comprising a shank that is surrounded and gripped by said circumferentially-spaced ribs and comprises a head at one end, a tapered point at the opposite end, a drill portion that extends away from said tapered point for a fixed distance, a screw portion commencing from adjacent said drill portion and extending toward said head, said drill portion having a trailing end adjacent to said screw portion, and at least two blades located at said trailing end of said drill portion, said blades projecting laterally from said screw fastener and having a radius greater than the maximum radii of said drill and screw portions, said head having cutting edges on a side thereof facing said shank; (b) positioning said strip so that the first-in-line of said screw fasteners is located in axial alignment with the rotatably drivable screw driver bit of a powered rotary screw driver apparatus; (c) engaging the head of said first-in-line screw fastener with said screw driver bit and operating said screw driver apparatus so as to cause said screw driver bit to rotatively expel said screw fastener out of said plastic strip and rotatively drive said fastener through said relatively soft structural member into said relatively hard structural member, with said cutting edges cutting away said ribs as said screw fastener is rotatively driven in a direction to expel it from said plastic strip and the driving of said fastener into said relatively hard structural member comprising first rotating said fastener to cause said drill portion to penetrate said relatively soft structural member in a drilling action and then, when said fastener has engaged said relatively hard structural member, repetitively impacting said fastener while simultaneously subjecting it to rotational torque, whereby to cause said fastener to penetrate said relatively hard structural member and lock said relatively soft structural member to said to relatively hard structural member; (d) disengaging said screw driver bit from said first-in-line screw fastener; (e) advancing said strip so as to locate the next-in-line screw fastener in axial alignment with said screw driver bit; (f) repeating step (c) to drive said next-in-line screw fastener through said relatively soft structural member into said relatively hard structural member; (g) disengaging said screw driver bit from said next-in-line screw fastener; and (h) repeating steps (b) to (d) as many times as required to complete attachment of said relatively soft structural member to said underlying relatively hard structural member made of metal.