Die for, method of making, and fastener with lobed primary thread lead and interposed dual auxiliary thread lead with improved substrate entry end portion

A threaded fastener adapted to be threadedly inserted into a substrate, 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 substrate, as said threaded fastener is threadedly inserted into the substrate, such that the debris from the substrate does not interfere with the insertion of said threaded fastener into the substrate whereby insertion torque levels, characteristic of the threaded insertion of said threaded fastener into the substrate, are relatively low and increase at a substantially low, constant rate, so as to, in turn, permit said threaded fastener to achieve substantially enhanced depth penetration within the substrate.

A thread rolling die for forming a threaded fastener, comprising:

• a body portion having a longitudinal axis;
• a working face disposed upon said body portion;
• a plurality of first, primary thread rolling die threads, disposed upon said working face of said body portion and oriented at a predetermined angle with respect to said longitudinal axis of said body portion, for forming a first, primary thread lead, comprising a plurality of first, primary threads, upon a blank member, wherein said plurality of first, primary thread rolling die threads are spaced from each other by means of first predetermined transversely spaced distances such that the first, primary threads are successively formed upon the blank member at first predetermined positions which are spaced from each other by means of first predetermined axially spaced distances;
• a plurality of recesses formed upon said plurality of first, primary thread rolling die threads for forming a plurality of lobe members upon said first, primary thread lead wherein at least one of said plurality of lobes will have 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;
• and
• a plurality of sets of second, auxiliary thread rolling die threads, disposed upon said working face of said body portion at positions transversely interposed between said plurality of first, primary thread rolling die threads and oriented at a predetermined angle with respect to said longitudinal axis of said body portion, for forming a dual set of second, auxiliary thread leads, each comprising a plurality of second, auxiliary threads, upon the blank member, wherein said plurality of second, auxiliary thread rolling die threads, comprising each one of said plurality of sets of second, auxiliary thread rolling die threads, are spaced from each other by means of second predetermined transversely spaced distances such that, as a result of said disposition of said plurality of sets of second, auxiliary thread rolling die threads, for forming said dual set of second, auxiliary threads, between said plurality of first, primary thread rolling die threads, when the plurality of first, primary threads are successively formed upon the blank member at the first predetermined positions, the distances through which material portions of the blank member, utilized for forming the plurality of first, primary threads upon the blank member, need to be moved is effectively minimized thereby, in turn, minimizing the length dimension of said thread rolling die required to completely form the threaded fastener from the blank member.

A method of forming a threaded fastener, comprising the steps of:

• providing a pair of thread rolling dies wherein each one of said pair of thread rolling dies comprises a body portion having a longitudinal axis;
• a working face disposed upon said body portion;
• a plurality of first, primary thread rolling die threads, disposed upon said working face of said body portion and oriented at a predetermined angle with respect to said longitudinal axis of said body portion, for forming a first, primary thread lead, comprising a plurality of first, primary threads, upon a blank member during a thread rolling process, wherein said plurality of first, primary thread rolling die threads are spaced from each other by means of first predetermined transversely spaced distances such that said first, primary threads will be successively formed upon said blank member at first predetermined positions which are spaced from each other by means of first predetermined axially spaced distances;
• a plurality of recesses formed upon said plurality of first, primary thread rolling die threads for forming a plurality of lobe members upon said first, primary thread lead wherein at least one of said plurality of lobes will have 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;
• and a plurality of sets of second, auxiliary thread rolling die threads, disposed upon said working face of said body portion at positions transversely interposed between said plurality of first, primary thread rolling die threads and oriented at a predetermined angle with respect to said longitudinal axis of said body portion, for forming a dual set of second, auxiliary thread leads, each comprising a plurality of second, auxiliary threads, upon said blank member during said thread rolling process, wherein said plurality of second, auxiliary thread rolling die threads, comprising each one of said plurality of sets of second, auxiliary thread rolling die threads, are spaced from each other by means of second predetermined transversely spaced distances;
• positioning said pair of thread rolling dies with respect to each other such that said working faces of said pair of thread rolling dies are oppositely disposed toward each other in a spaced apart mode;
• interposing said blank member between said oppositely disposed spaced apart working faces of said pair of thread rolling dies;
• and
• rolling said blank member between said pair of spaced apart thread rolling dies such that, as a result of said disposition of said plurality of sets of second, auxiliary thread rolling die threads, for forming said dual set of second, auxiliary threads, between said plurality of first, primary thread rolling die threads, when said plurality of first, primary threads are successively being formed upon said blank member at the first predetermined positions, the distances, through which material portions of said blank member utilized for forming said plurality of first, primary threads upon said blank member need to be moved, is effectively minimized thereby, in turn, minimizing the length dimensions of said pair of thread rolling dies required to completely form said threaded fastener from said blank member.