| 摘要 |
The equipment consists of a folding beam attached at right-angles via a slide socket to a 5,500 mm high column positioned on a concrete foundation. The first part of the beam is 2500 mm long, and the second part extends for 2000 mm. It carries a drill crown, and by raising and lowering the slide socket, the crown position, when folded up, over the column foot varies between 3,500 and 4,500 mm. - A speed-governed motor drives the drill crown via a flexible union and shaft in a 2,100 mm long steel tube. The shaft is located at the bottom in needle bearings built into the drilling crown, and at the top in ball bearings. The wood dust produced by the drill crown is sucked upwards between the shaft and the steel tube inner wall. The tube having 6 mm. holes to air intake to improve dust movement. |
