Patent ID: 8437220

Claim:
An acoustic isolator for use with tubular assemblies including an acoustic wave transmitter, the acoustic isolator comprising: a first coaxial tubular member with a first member length including a proximal end and a distal end, a first acoustic impedance and a first acoustic transit time; a second coaxial tubular member with a second member length including a proximal end and a distal end, a second acoustic impedance and a second acoustic transit time; said first and second diameters being such that said first member can be placed inside of the second tubular member without making contact with said second tubular member; the first and second tubular members being aligned so as not to be in physical contact; a first coupling located at the proximal end of the first and second members, said first coupling restricting the motions of said members and said coupling whereby said motions are approximately equalized at their common points of contact thereby allowing exchange of acoustic energy between the tubular assemblies above said first coupling and said tubular members below said first coupling; a second coupling placed at the distal end of the first and second members, said second coupling restricting the motions of said members to be equal at their common points of contact thereby allowing exchange of acoustic energy between the tubular assemblies below said second coupling and said tubular members above said second coupling; the lengths, acoustic impedances, and transit times of said tubular members aligned so that by means of constructive and destructive wave interference the acoustic energy transmitted through the upper coupling results in reduced motion and reduced force in the second coupling, and acoustic energy transmitted through the lower coupling results in reduced motion and force in the first coupling whereby downward traveling acoustic energy is selectively reflected upward and upward traveling acoustic energy is selectively reflected downward; the first and second coaxial tubular members comprised of different acoustic structure materials, such that acoustic waves originating at the distal end travelling along said coaxial tubular members travel at substantially different wave speeds; said different acoustic structure materials of equal impedance value; and said differing wave speeds inducing a phase difference between said coaxial tubular members, said phase difference depending on the length of the members.