US4867269A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tuned self-damping convoluted conduit
Assignee: Titeflex Corp
•
Filing: 1987-10-01
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Granted: 1989-09-19
•
Expires: 2007-10-01
Abstract
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.
Inventors
- 👤 James M. Lalikos
- 👤 Harold K. Waite
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:52
CPC Classifications
F; F16; F16L; F16L11/00; F16L11/04; F16L11/11; F01; F01N; F01N13/00; F01N13/18; F01N13/1805; F01N13/1811; F01N13/1816; F01N13/08; F16L27/00; F16L27/10; F16L27/107; F16L27/108; F16L27/1085; F01N2530/00; F01N2530/26
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
125 words
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.
Claim 2
Dependent Claim
125 words
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.
Claim 3
Dependent Claim
40 words
The conduit of claim 1 wherein said stainless steel tape has a width in an approximate range of one to twenty times an outside diameter of conduit and a thickness in an approximate range of said 0.001 to 0.010 inches.
Claim 4
Dependent Claim
21 words
The conduit of claim 1 wherein said area in which overlap is selectable extends axially along the length of said conduit.
Claim 5
Dependent Claim
18 words
The conduit of claim 1 wherein said area in which overlap is selectable extends peripherally around said conduit.
Claim 6
Dependent Claim
22 words
The conduit of claim 1 wherein said stainless steel comprises a 400 series type, including #409, #410, #416 and #430 stainless steel.
Claim 7
Dependent Claim
26 words
The conduit of claim 1 wherein said stainless steel comprises a 300 series type, including #302, #304, #316 and #321 stainless steel and related low-carbon alloys.
Claim 8
Dependent Claim
27 words
The conduit of claim 1 and a braided stainless steel stocking surrounding said conduit, said stocking being made of wire 0.008 inches to 0.032 inches in diameter.
Claim 9
Dependent Claim
19 words
The conduit of claim 7 wherein said braid has a pack in the approximate range of 50% to 95%.
Claim 10
Dependent Claim
22 words
The conduit of claim 7 wherein said braid is woven with a tension applied in the approximate range of 5- to 70-pounds.
Claim 11
Dependent Claim
25 words
The conduit of claim 1 wherein said tape is wrapped around a tube made of inconel, said tape and tube being convoluted as a unit.
Claim 12
Dependent Claim
19 words
The conduit of claim 1 wherein said overlap area extends over an arc of 180° of conduit wall circumference.
Claim 13
Dependent Claim
19 words
The conduit of claim 1 wherein said overlap area extends over an arc of 0° of conduit wall circumference.
Claim 14
Dependent Claim
19 words
The conduit of claim 1 wherein said overlap area extends over an arc of 0°-180° of conduit wall thickness.
Claim 15
Dependent Claim
14 words
The conduit of claim 1 wherein said stainless steel is an austenitic stainless steel.
Claim 16
Dependent Claim
13 words
The conduit of claim 1 wherein said stainless is a ferritic stainless steel.
Claim 17
Dependent Claim
23 words
The conduit of claim 1 wherein said conduit has an internal surface, and an inconel foil lining the internal surface of said conduit.
Claim 18
Dependent Claim
43 words
The conduit of claim 1 and a wire braid sleeve covering said cunduit, said braid sleeve having a tightness or looseness which is selected on a basis of the mass and spring rate imparted to said conduit in order to detune said conduit.
Claim 19
Dependent Claim
21 words
The conduit of claim 17 wherein said braid is tight when said conduit is exposed to severe lateral and torsional flexure.
Claim 20
Dependent Claim
17 words
The conduit of claim 18 and tuning rings positioned over said tight braid to detune said conduit.
Claim 21
Dependent Claim
21 words
The conduit of claim 17 wherein said braid is loose when said conduit is exposed to axial lateral and torisonal flexure.
Claim 22
Dependent Claim
17 words
The conduit of claim 20 and tuning rings positioned over said loose braid to detune said conduit.
Claim 23
Independent Claim
158 words
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.
Claim 24
Independent Claim
158 words
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.
Claim 25
Dependent Claim
39 words
The method of claim 22, further comprising the step of wrapping said tape axially so that said mass and spring rate may be varied around a circumference of said conduit in order to provide a selected amount of overlap.
Claim 26
Dependent Claim
39 words
The method of claim 22 further comprising the step of wrapping said tape helically so that said mass and spring rate may be varied along the length of said conduit in order to provide a selected amount of overlap.
Claim 27
Dependent Claim
25 words
The method of claim 22 and the added step of surrounding said conduit with a vibration absorbing stocking for damping resonant vibrations within said conduit.
Claim 28
Dependent Claim
12 words
The method of claim 25 wherein said stocking is a tight braid.
Claim 29
Dependent Claim
12 words
The method of claim 25 wherein said stocking is a loose braid.
Claim 30
Dependent Claim
21 words
The method of claim 25 wherein said stocking is a braid having a braid angle in the approximate range of 45°±25°.
Claim 31
Dependent Claim
72 words
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°±25°.
Claim 32
Dependent Claim
72 words
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°±25°.
Claim 33
Dependent Claim
32 words
The conduit of claim 29 wherein said sleeve is slack, having a clearance between said sleeve and said conduit which is equal to at least 10% of the diameter of the conduit.
Claim 34
Dependent Claim
47 words
The conduit of claim 29 wherein said braid has a spring rate and there is an inverse relationship between a clearance between said braid and said conduit and the spring rate of said braid, whereby the greater the clearance, the less the spring rate, and vice versa.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-18 | 1993-03-20 | 1993-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-18 | 1997-03-20 | 1997-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-18 | 2001-03-20 | 2001-09-19 | $7700.00 | Window Closed / Lapsed |