Patent ID: 8978712
Filing Date: 2015-03-17
Classification: B60H,F16L,Y10T

Abstract:
1. A flexible tube having an internal surface and an external surface, with at least one folding bellows extending along at least a portion of the tube, the bellows comprising a plurality of adjacent convolutes formed in the wall of the tube and extending circumferentially around the tube, where the plurality of adjacent convolutes define a plurality of interspersed peaks and valleys transverse to an axial longitudinal direction of the tube, and the external surface between adjoining peaks and valleys is curvilinear in the axial longitudinal direction, wherein at least one convolute has two opposite bending zones and two opposite restricted elongation zones, with the restricted elongation zones between the opposite bending zones, and the height of the external surface of the peak of the at least one convolute in the restricted elongation zones is below the height of the external surface of the peak of the at least one convolute in the bending zones but still above the external surface of the tube, and the at least one convolute has a first wall thickness about the periphery of at least one restricted elongation zone and a second wall thickness about the periphery of the bending zones, wherein the first wall thickness is greater than the second wall thickness.