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.

Abstract: A tuned convoluted 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 tape in successive layers to form a multiple layered wall. The width of the tape may be such that each alternate convolution has more layers than its two adjacent neighboring convolutions. A sleeve or stocking loosely fits over the conduit and is clamped by a band onto the conduit to prevent vibration of the conduit at that clamped location.

Abstract: A convoluted conduit 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 tape in successive layers to form a multiple layered wall. The width of the tape may be such that each alternate convolution has more layers than its two adjacent neighboring convolutions. Another way of making the conduit is to provide a plurality of coaxially nesting tubes which cooperate to form a wall thickness. Brazing or packing material may be positioned between adjacent layers of tape to seal the conduit and to make the wall behave at that point as a single layer.

Abstract: A conduit is adapted for use in an environment where it is subjected to excessive vibration. An example of such an environment is the exhaust system on an engine. To preclude material fatigue responsive to such vibration, successive convolutions are varied in height, thickness, slope, spacing, or a combination thereof. Hence, each incremental length of the conduit has a different resonant frequency as compared to the resonance frequency of its adjacent neighboring incremental lengths so that there is no overall high amplitude resonance along the entire length of the conduit, taken as a whole. On the other hand, once the resonance is sufficient to provide self-damping, efforts should be made to maximize the uniformity of vibration response so that bending forces will not be concentrated in one area of the conduit.

Abstract: The invention provides a hose that withstands a vacuum which is considered to be approximately two to three times greater than the vacuum withstood by the best known previously available pliable convoluted semirigid plastic hoses of comparable designs. To fabricate the hose, a bobbin of wire stock is unwound, with the wire preferably being pulled off the end of the bobbin. The wire is then looped around a spool to form it into a spiral or coil having a preset diameter which is proportionately smaller than the diameter of a preformed, semirigid convoluted plastic hose. While the pulled wire is still substantially extended, it is taken up by being rolled upon the plastic hose, thereby snapping the preset formed wire spiral into the spiral convolutions formed in the surface of the hose. If desired, the spiral or coil might be pulled off the end of the samller diameter spool to impart a twist thereto.

Abstract: A braided-wire sheathing for high pressure hose or the like composed of interwoven bundles of high tensile strength wire. Within each bundle, the longer wires are twisted helically about the shorter wires such that all of the wires are under substantially equal tension. The interwoven bundles are grouped in pairs in a two-over, two-under pattern, the two bundles in each pair being twisted in opposing rotational directions.

Abstract: The invention provides a hose that withstands a vacuum which is considered to be approximately two to three times greater than the vacuum withstood by the best known previously available pliable convoluted semirigid plastic hoses of comparable designs. To fabricate the hose, a bobbin of wire stock is unwound, with the wire preferably being pulled off the end of the bobbin. The wire is then looped around a spool to form it into a spiral or coil having a preset diameter which is proportionately smaller than the diameter of a preformed, semirigid convoluted plastic hose. While the pulled wire is still substantially extended, it is taken up by being rolled upon the plastic hose, thereby snapping the preset formed wire spiral into the spiral convolutions formed in the surface of the hose. If desired, the spiral or coil might be pulled off the end of the smaller diameter spool to impart a twist thereto.

Abstract: Apparatus for interweaving bundles of wire strands over the surface of a tubular core to form a braided sheath. Each multi-strand bundle is wound on a supply bobbin which forms part of a bobbin-carrier. The bobbin-carriers are driven in opposing directions around the tubular core along sinuous paths as the core is drawn longitudinally with respect to the carriers. Each bundle of wire strands is passed through an elongated slot in a twisting member which, when rotated, wraps those strands under less tension about those strands under greater tension, continually equalizing length and tension among the bundled strands during the braiding operation.