Lacing

Abstract: A speed lacing device for an article of footwear having a rigid portion comprising a curved neck and a fastening tail that together define an almost-friction-free sliding surface for a lacing cord, the lacing cord being in contact with the sliding surface in either a state of tension or a state of relaxation. The speed lacing device also having a flexible portion that extends from the rigid portion to form an upper half of a closed loop through which the lacing cord is threaded.

Abstract: The influence on coupling vibrations among shaft-torsion, blade-bending and lacing wire coupling vibrations of a multi-disk rotor system with grouped blades was investigated analytically. The natural frequencies and the mode shapes of the system were solved for one-to four-disk cases as examples. First, numerical results showed how the natural frequencies varied by lacing wires and disks in a multidisk rotor system. The diagrams of the coupling mode shapes were drawn. From the results, the inter-blade (BB) modes, the shaft-blade (SB) modes and the lacing wires-blade (LB) modes change rules were given in this paper. Numerical calculation also revealed three interesting results that the natural frequencies were affected by lacing wire constant, lacing wire location and the disk distance. In the rotation effects, the multi-disk has drawn three important phenomena. The times of instability will due to the number of disk, the more disk rotor causes instability earlier than the less disk case and the lacing wires could not affect the system instability.

Abstract: The Assumed mode method (AMM) and Finite element method (FEM) were used. Their results were compared to investigate the coupled shaft-torsion, disk-transverse, and blade-bending vibrations in a flexible-disk rotor system. The blades were grouped with a spring. The flexible-disk rotor system was divided into three modes of coupled vibrations: Shaft-disk-blade, disk-blade, and blade-blade. Two new modes of coupled vibrations were introduced, namely, lacing wires-blade and lacing wires-disk-blade. The patterns of change of the natural frequencies and mode shapes of the system were discussed. The results showed the following: first, mode shapes and natural frequencies varied, and the results of the AMM and FEM differed; second, numerical calculation results showed three influencing factors on natural frequencies, namely, the lacing wire constant, the lacing wire location, and the flexible disk; lastly, the flexible disk could affect the stability of the system as reflected in the effect of the rotational speed.