Tuned self-damping convoluted conduit
AssigneeTiteflex Corporation
InventorsJames M. Lalikos, Harold K. Waite
Life of this patent
Estimating the term…
Abstract
A tuned, convoluted, stainless steel conduit assembly is especially well adapted for use in hostile environments subject to vibrations which bring on fatigue failures. To prevent the conduit from having a uniform resonance throughout its length, the convolutions have a variable wall thickness. One way this variable wall thickness may be achieved is by forming the conduit walls by wrapping stainless steel tape in successive layers to form a multiple layered wall. The width of the tape may be such that some convolutions have more layers than other neighboring convolutions. A stainless steel sleeve or stocking loosely fits over the conduit and is clamped by one or more tuning bands onto the conduit to prevent vibration of the conduit at that clamped location.
Claims31
A convoluted stainless steel conduit for use in an automotive exhaust system, said conduit experiencing vibrations during operation of an automotive vehicle on which said conduit is mounted, said conduit comprising stainless steel tape wrapped upon itself to form a multi-layer tube, said conduit having a mass, spring rate, and length, said tape wrap having areas which have a selectable overlap in order to give the tube different wall thicknesses and to vary the mass and spring rate of said wall in different locations along the length thereof, said areas of different wall thicknesses being distributed throughout the conduit to detune the conduit so that said conduit will resist vibrations which are sympathetic with the vibrations which ocur during the operation of said automotive vehicle.
A method of forming a conduit having a mass, spring rate and a length for conveying hot gases away from an internal combustion engine, said method comprising the steps of:
- (a) constructing a conduit from a plurality of layers of stainless steel tape wrapped upon itself to form a tube, overlapping said metal tape during said wrapping to vary the mass and the spring rate by a selection of wall thickness of said conduit at selected locations along said tube, said overlapping being positioned to detune said conduit at frequencies which are anticipated during normal operations of said internal combustion engine,
- (b) convoluting said wrapped stainless steel tube to convert said layers of tape into a unitary wall having variations in mass and spring rate distributed along the length there, and
- (c) providing a coupling on said conduit for connecting said conduit to said internal combustion engine in order to convey said hot gases away from said engine.
A convoluted conduit comprising multiple layers of stainless steel tape which are wound upon themselves with a variable geometric configuration, said conduit having mass and spring rates which vary along incremental lengths of said conduit as a result of said geometrical configuration, and a braid sleeve having a pack which covers at least 50% of a surface area of said conduit, said braid having a lead angle in the order of 45.degree..+-.25.degree..
Dependencies are inferred from the claim text.