| 摘要 |
PCT No. PCT/SE89/00202 Sec. 371 Date Oct. 9, 1990 Sec. 102(e) Date Oct. 9, 1990 PCT Filed Apr. 12, 1989 PCT Pub. No. WO89/09685 PCT Pub. Date Oct. 19, 1989.A driving device comprises at least one chain (16) in the form of a closed loop. The chain is connected to at least one driving member arranged to cause the chain to orbit. Furthermore, the chain is laid over diverting members which in combination with the driving member determine the form of the loop. A rubber element (17) is arranged on the face of the chain located outermost in the loop and forms a configuration generally enclosing the chain loop. The rubber element (17) is in a driving force transmitting engagement with the chain (16) to be caused to orbit thereby. The rubber element (17) serves for engagement with for instance tree trunks over a large surface. |
