Transmission line assembly including means for reducing vibrations and method of making same

A transmission line assembly including means for reducing transmission line vibration comprising:

• an outer tubular sheath having an inner surface forming an inner diameter;
• an inner tubular wall member firmly fixed to said inner surface of said outer tubular sheath;
• a transmission line disposed within said inner tubular wall member for transmitting energy;
• a plurality of radially contracted tubular sections having axial lengths at regularly spaced axial intervals formed in said inner tubular wall member and contiguously surrounding said transmission line for protecting, centering and supporting said transmission line within said outer tubular sheath;
• and
• a plurality of radially enlarged sections formed in said inner tubular wall member having axial lengths greater than the axial lengths of said radially contracted tubular sections and having unstressed outer diameters smaller than said inner diameter of said outer tubular sheath.

A method of manufacturing a transmission line assembly including means for reducing transmission line vibration, said assembly including a transmission line disposed within a thermoretractable plastic tube disposed within a tubular sheath, said transmission line having a smaller diameter than the inside diameter of said tube, wherein said method comprises:

• inserting said transmission line into said tube;
• heating said thermoretractable plastic tube at regular axial intervals so as to form a tubular wall member having tubular uncontracted sections and tubular contracted sections wherein said tubular contracted sections contiguously surround said transmission line;
• and
• inserting said transmission line fitted with said tubular wall member into said sheath, said sheath having an inside diameter substantially the same as the outside diameter of said uncontracted sections of said tubular wall member for friction fitting engagement therewith.