Adjustable eccentricity orbital tool

摘要

An orbital sander includes a motor, a housing, and a drive shaft rotatably driven by the motor about a drive axis. A bearing freely rotatable about a bearing axis is disposed eccentrically with respect to the drive axis to define an eccentric offset. A sanding platen is supported by the bearing. An input sleeve is interposed between the bearing and the drive shaft, and has an input axis spaced from the drive axis. An output sleeve, positioned within and engaging the bearing, encircles the input sleeve and is rotatable about the input axis. The sleeves are circumferentially aligned, thereby minimizing the height of the sander. A stop member cooperates with the sleeves to allow for rotation of the sanding platen while preventing axial movement of the sleeves. The sleeves have cooperating surfaces which limit their relative movement, defining maximum and minimum eccentric offsets based on the direction of motor rotation. An alternative embodiment provides cooperating surfaces which are capable of being separated, thus providing more than two possible eccentric offsets without requiring reversal of the direction of motor rotation.