| 摘要 |
This invention relates to a rotary orbital sander and aims at avoiding discomfort on the operator by rotational unbalance and the risk of harm or damage to operator and surroundings, while offering stability and structural rigidity. This sander includes a motor housing (12), a drive shaft (42) having an offset projecting portion (44), a pinion gear housing (16) affixed to the motor housing (12), a carrier (50) supported upon the shaft off-set projecting portion (44) by two parallel arranged ball bearings (48), a sanding pad assemblage (60) removably attached to the carrier (50), intermeshing spur gears (54, 52) arranged on the pinion gear housing (16) and the carrier (50), and a counter-balance weight (62) rotating with the shaft portion (44) and having a particular position of its center of gravity, said pinion gear housing (16) having a circular cavity (56) surrounding the carrier (50) and engageable thereby (at 58) as it revolves, to provide rotational support for the carrier (50). |
