| 摘要 |
An electrical conduit is substantially circular and is internally formed with zig-zag ridges. The ridges are angularly equispaced and have portions of constant pitch a joined at corners, and the ridges contact a cable in the conduit at regions K each defined by the formula: Ar = 0.16b2zL K, where A = the surface of area R, equal to between 4,5mm2 and 32mm2, r = the radius of the conduit or D/2, b = the width of the contact region K, z = the number of ridges 1, and L K = axial length of each ridge straight portion. The straight-portion pitch g in radians is equal to: g = r'al L K and is between 0.0o1rad and 1.2rad, radius r being equal to between 12mm and 100mm and L K is between 500mm and 10,000mm, depending on the diameter of the cable which can range from 5mm to 45mm. |
