Expanding Dowel Pin

A method of providing an expanding dowel-pin, the method comprising:

• providing an upper collet, the upper collet including:
• an upper-collet proximal end and an upper-collet distal end;
• and
• an upper-collet, inside-conical bore that is tapered more narrowly towards the upper-collet proximal end and having one or more upper-collet slits extending along a length of the upper-collet, inside-conical bore;
• and
• providing a double-tapered cylinder, the double-tapered cylinder including:
• a double-tapered cylinder first end, a double-tapered cylinder second end, and a double-tapered cylinder middle positioned between the double-tapered cylinder first end and the double-tapered cylinder second end;
• and
• the double-tapered cylinder having a first tapered cone tapering more narrowly from the double-tapered cylinder middle towards the double-tapered cylinder first end and a second tapered cone tapering more narrowly from the double-tapered cylinder middle to the double-tapered cylinder second end;
• and
• providing a lower collet, the lower collet including:
• a lower-collet proximal end and a lower-collet distal end;
• a lower-collet, inside-conical bore that is tapered more narrowly towards the lower-collet proximal end and having one or more lower-collet slits extending along a length of the lower-collet, inside-conical bore;
• and
• a lower-collet, inside-straight bore with lower-collet internal screw threads, the lower-collet, inside-straight bore extending from the lower-collet, inside-conical bore to the lower-collet proximal end;
• wherein:
• the upper collet, the double-tapered cylinder, and the lower collet, are configured, in that order, to have a bolt pass therethrough;
• the lower-collet internal screw threads are configured to engage the bolt, such that, when the bolt is rotated a first direction relative to the lower collet, the upper collet and the lower collet are configured to be compressed together by the bolt, resulting in the first tapered cone forcing the expansion of the upper-collet, inside-conical bore and the second tapered cone forcing the expansion of the lower-collet, inside-conical bore.

An expanding dowel-pin, comprising:

• an upper collet including:
• an upper-collet proximal end and an upper-collet distal end;
• an upper-collet torsional captive flats and an upper-collet torsional locking feature;
• and
• an upper-collet, inside-conical bore that is tapered more narrowly towards the upper-collet proximal end;
• the upper-collet, inside-conical bore having one or more upper-collet slits extending along a length of the upper-collet, inside-conical bore;
• a double-tapered cylinder including:
• a double-tapered cylinder first end, a double-tapered cylinder second end, and a double-tapered cylinder middle positioned between the double-tapered cylinder first end and the double-tapered cylinder second end;
• and
• the double-tapered cylinder having a first tapered cone tapering more narrowly from the double-tapered cylinder middle towards the double-tapered cylinder first end and a second tapered cone tapering more narrowly from the double-tapered cylinder middle to the double-tapered cylinder second end;
• and
• a lower collet including:
• a lower-collet proximal end and a lower-collet distal end;
• a lower-collet torsional locking feature;
• a lower-collet, inside-conical bore that is tapered more narrowly towards the lower-collet proximal end, the lower-collet, inside-conical bore having one or more lower-collet slits extending along a length of the lower-collet, inside-conical bore;
• and
• a lower-collet, inside-straight bore with lower-collet internal screw threads, the lower-collet, inside-straight bore extending from the lower-collet, inside-conical bore to the lower-collet proximal end;
• wherein:
• the upper collet, the double-tapered cylinder, and the lower collet are, in that order, configured to have a bolt pass therethrough;
• the lower-collet internal screw threads are configured to engage the bolt, such that, when the bolt is rotated a first direction relative to the lower collet, the upper collet and the lower collet are configured to be compressed together by the bolt, resulting in the first tapered cone forcing the uniform expansion of the upper-collet and the second tapered cone forcing the uniform expansion of the lower-collet, the uniform expansion of the upper-collet is independent of the uniform expansion of the lower-collet;
• the upper-collet torsional captive flats are configured to be held from rotating relative to the bolt;
• the upper-collet torsional locking feature is configured to interface with and prevent rotation of the lower-collet torsional locking feature and rotation of the lower collet relative to the bolt;
• and
• the double-tapered cylinder is configured such that compression by the bolt of the upper collet towards the lower collet does not deform the double-tapered cylinder and the double-tapered cylinder does not bind the bolt.