| 摘要 |
<p>Saw cords used for sawing natural or manmade stony materials are made of saw beads threaded on a steel cord (52,522,522'), wherein the saw beads are separated by polymer spacers. The saw beads comprise a metal sleeve (204, 304) of which the outer surface is covered with an abrasive layer. The inventors observed that saw cords returning from the field frequently failed due to saw beads that begin to rotate during use thereby eroding away the polymer between the steel cord and the inner of the saw bead. Eventually, the polymer is worn away and the outer steel filaments of the steel cord are ground away due to the interaction with saw dust and water. The inventors provide the inner surface of the sleeve with two sets (214) of parallel grooves in a first (206, 306) and second (208,308) axial part of the sleeve. The two sets of parallel grooves differ in at least one of the groove angle (α,β), the groove offset (Δ) or the groove spacing (1l, D2), thereby preventing axial movement of the sleeve and blocking the rotation of the saw bead.</p> |
