Tuned self-damping convoluted conduit

An elongated tuned conduit having a length and having successive convolutions, said conduit having a mass and spring rate distributed along said length, said conduit being part of an automotive vehicle exhaust system and being exposed to an environment of vibrations when said vehicle operates, which environmental vibrations may set the conduit into sympathetic vibrations if no correction is provided to prevent said sympathetic vibration, said conduit naturally developing at least one loop responsive to said sympathetic vibrations if not prevented from doing so, tuning means comprising a stocking loosely surrounding said conduit for changing the mass and spring rate of said conduit, and tuning band means for clamping said stocking to said conduit in at least one location where said loop would otherwise form.

A tuned conduit extending between two anchor points at opposite ends of said conduit, said conduit being exposed to automotive caused vibrations, said conduit having at least one layer, a stocking made of a flexible metallic wire material surrounding said conduit and extending between said two anchor points, said stocking also being exposed to said automotive caused vibrations, and at least one tuning band surrounding said stocking for modifying said conduit response to the automotive caused vibrations of said conduit and stocking, the location of said band relative to said two anchor points being selected to provide different resonant characteristics in different areas of said conduit, said resonant characteristics opposing said vibrations to provide self-damping within said conduit.

A tuned conduit having a length and comprising at least one layer forming a conduit wall;

• a stocking made of a flexible material loosely surrounding, in contact with, and extending along the length of said conduit;
• the flexible material of said stocking being integrally formed to provide at least one unitary tuning ring located at a loop in a naturally occurring vibration pattern of said conduit, said tuning ring having an internal diameter which secures said stocking to said conduit.

A tuned conduit having successive convolutions for carrying fluids, a stocking made of flexible metallic material loosely surrounding said conduit and being in direct contact with the conduit, said conduit being exposed to an environment having vibrations, said flexible metallic material being formed so that said stocking itself is integrally formed to provide at least one unitary tuning ring in at least one location where the conduit might otherwise form a loop in response to said environmental vibrations.

A tuned convoluted conduit for use in an automotive vehicle exhaust system, said vehicle having a characteristic vibrational pattern, said conduit comprising a ribbon of tape which is axially and longitudinally wound upon itself to form a tube, said tape having opposing longitudinal edges angularly positioned relative to each other in order to provide a stiffened strip of selected width extending along a length of the conduit, said angular position being taken relative to an axis of said tube, said conduit being convoluted in a manner which cooperates with said stiffened strip to detune said conduit at said vibration pattern.

A conduit for use in an exhaust system for an internal combustion engine, said exhaust system experiencing a pattern of vibrational frequencies, said conduit having a length and being formed by multiple layers of tape wrapped upon themselves, said conduit further being convoluted to form a unitary conduit wall with individual convolutions having a variable geometry relative to other convolutions, said conduit wall having a mass and a spring rate distributed along the length thereof, said variable geometries being distributed along said conduit in a manner which detunes said conduit in at least one frequency of said vibrational pattern, and a stocking made of braided metallic wire material surrounding said conduit and producing a vibrational response characteristic which cooperates with said convoluted geometry to further detune said conduit in at least said one frequency, said convolutions and the braid characteristics cooperating to control and vary the mass and the spring rate of the conduit to change its natural vibrational response.

An elongated conduit for use in an automotive exhaust system, said conduit having a length with a mass and a spring rate distributed along the length thereof, said conduit being formed by a plurality of layers of tape wound upon themselves and convoluted to form a unitary conduit wall with alternate peaks and valleys distributed along the length of said conduit, the configuration of said peaks and valleys being selected to vary the mass and spring rate of said conduit in a manner which detunes vibrational resonance of said conduit at selected frequencies, a stocking made of metallic wire surrounding said conduit and producing vibrational responses relative to said conduit which further controls said resonance, mechanical anchoring means attached to said conduit and stocking at opposite ends thereof for joining them together, said anchoring means being adapted to attach said conduit and stocking into said exhaust system, and tuning rings surrounding said stocking for securing said stocking to said conduit at locations along the length of said conduit where loops might otherwise be formed by said detuned resonant vibrations.

A convoluted conduit comprising at least two co-axial layers of axially wrapped tape which have intimate contact between said layers forming a multi-layer conduit, said conduit being convoluted after being wrapped in order to form a unified conduit wall, a stocking made of flexible metallic braid loosely surrounding said conduit, and said metallic braid stocking being integrally formed to provide at least one tuning ring located at a loop in a naturally occurring vibrational pattern of said conduit and said tuning ring securing said stocking to said conduit.