| 摘要 |
The present invention concerns a flexible, tubular device e.g. a bellows with an internal diameter up to 60 millimeters, said device comprising one or more corrugated convolutions (2), said convolutions having an overall bell-like shape with rounded top portions (T) and rounded bottom portions (B,B'). The novel aspects involve that the curvature of the outside surface of the convolutions (2) is numerically smaller at the top portions (T) than at the bottom portions (B,B'), said curvature being derived from a curve (6) defined as the intersection of the outside surface (4) of the device and a plane through the longitudinal axis (8) of the device, as well as they involve that the curvature of said curve changes sign only once at a change position (P,P') located between a top portion (T) and an adjacent bottom portion (B,B"), and that the length of a first section (7) on the curve (6) is at least 10% longer than the length of a second section (9) on the curve, said first section (7) extending from one change position (P) to an adjacent change position (P) via a top portion (T), and said second section (9) extending from one change position (P) to an adjacent change position (P') via a bottom portion (B,B'). This provides an improved design with increased durability due to increased flexibility at lower stresses, compared to the prior art. |
