| 摘要 |
A boom mower has a first arm (10) pivoted to the tractor, a second arm (12) pivoted to the end of the fist arm (10) and forming a guide (12), a pinion (106) in the guide, and a rack (104) displaceable through the guide (12) and carrying a cutting head (16) at its free end, so that the reach of the cutting head (16) on the tractor may be extended by use of the rack (104) and pinion (106). |
