摘要 |
<p>A cable (5) is inserted in a tube (2) wound on a tube reel (1). The cable is fed from a cable reel (6) through a cable-advancing unit (4) into a free inlet end (2.1) of the tube (2). Compressed air is applied to an air inlet (8) of the advancing unit (4), and led through the tube along the cable already inserted in the tube. The tube reel is put on a support 7, which is driven to a periodic movement in the vertical direction between to extreme positions (amplitude A, period P). During part of each period the movement is a free fall, or at least approximates a free fall. The movement may be sinusoidal with period P=2 pi [A/g]+E,fra 1/2+EE (g is gravitational constant). In this case, the support (7) may be part of a rotatably supported lever, or may be part of a seesaw. In addition, the movement may be the vertical component of a maintained swinging movement. In this case the support (7) may be the swinging part of a Chinese swing.</p> |