Patent ID: 7156600

Claim:
A threaded fastener adapted to be threadedly inserted into a workpiece, comprising: a shank portion having an axial extent; a tip portion formed upon one end of said shank portion; a first, primary thread lead disposed upon said shank portion and comprising a plurality of first, primary threads which are successively disposed upon said shank portion at positions which are spaced from each other by means of first predetermined axially spaced distances; a plurality of lobe members disposed along the length of said first, primary thread lead and upon said plurality of first, primary threads wherein at least a first one of said plurality of lobes has a variable height dimension, as considered in the direction extending from a root portion of said first, primary thread lead to a crest portion of said first, primary thread lead, and a variable width dimension as considered in the direction extending along said length of said first, primary thread lead; a dual set of second, auxiliary thread leads disposed upon said shank portion, wherein each one of said dual set of second, auxiliary thread leads comprises a plurality of second, auxiliary threads which are successively disposed upon said shank portion at positions which are spaced from each other by means of second predetermined axially spaced distances and which are interposed between said plurality of successively disposed first, primary threads; and first and second spaces, respectively defined between said tip portion of said threaded fastener and a first forwardmost one of said first, primary threads, and between said first forwardmost one of said first, primary threads and a second one of said first, primary threads, devoid of said second, auxiliary threads so as to be capable of accommodating debris from the workpiece, as said threaded fastener is threadedly inserted into the workpiece, such that the debris from the workpiece does not interfere with the insertion of said threaded fastener into the workpiece whereby insertion torque levels, characteristic of the threaded insertion of said threaded fastener into the workpiece, are relatively low and increase at a substantially low, constant rate.