Abstract: The present invention generally comprises a counterbalancing assembly for a random orbital machine including an adapter and a counterweight. The adapter includes a recess and the counterweight is disposed in the recess and detachably fastened to the adapter. In some aspects, the counterweight is fully enclosed within the recess. The adapter is configured for connection to a drive means for the machine and for connection to an abrasive pad assembly. The drive means is rotatable about a first axis of rotation. The abrasive pad assembly is rotatable about a second axis of rotation disposed parallel to the first axis of rotation. The adapter and the counterweight are configured to substantially counterbalance portions of the abrasive pad assembly not disposed concentrically about the first axis of rotation and forces to which the abrasive pad assembly is subjected to during use.

Abstract: A head portion for counterbalancing a random orbital machine including a first element adapted for connection to a drive means for the machine and to an abrasive pad assembly. The drive means is rotatable about a first axis of rotation and the abrasive pad assembly is rotatable about a second axis of rotation that is parallel to the first axis of rotation and lying within a plane common with the first axis. The head portion also includes a second element detachably connected to the first element. The first and second elements are configured to at least substantially counterbalance portions of the abrasive pad assembly not disposed concentrically of the first axis of rotation and forces to which the abrasive pad assembly is exposed during use as a result of the abrasive pad assembly engaging with a work surface.

Abstract: A pneumatically operated, random orbital sander is disclosed as having an upper seal adapted to retard the entry of dust into an exposed or lowermost motor shaft supporting bearing and a lower seal adapted to retard the entry of dust into a motor shaft mounted bearing serving to couple the motor shaft to a sanding pad or disc.

Abstract: A pneumatically operated, random orbital sander is disclosed as having an upper seal adapted to retard the entry of dust into an exposed or lowermost motor shaft supporting bearing and a lower seal adapted to retard the entry of dust into a motor shaft mounted bearing serving to couple the motor shaft to a sanding pad or disc.