Quarter sheet sander

Abstract

An orbital sander includes a housing, a drive unit within the housing having an electric motor defining a rotational axis, and a drive shaft coupled for co-rotation with the motor about the rotational axis having a fan rotatably coupled to the lower portion of the drive shaft. The fan includes a main body having a plurality of fan blades, an upper counterweight located on one side of the main body and a lower counterweight located on an opposite side of the main body for balancing the operation of the fan, and an interruption region located opposite the lower counterweight with fan blades located within the interruption region having a reduced mass. The orbital sander further includes a baseplate for selectively mounting a sanding sheet that is coupled to the lower portion of the drive shaft for orbital rotation about the rotational axis.

What is claimed is: 
     
         1 . An orbital sander comprising:
 a housing;   a drive unit within the housing, the drive unit including
 an electric motor defining a rotational axis, 
 a drive shaft coupled for co-rotation with the motor about the rotational axis, 
   the drive shaft including a lower portion, and
 a fan rotatably coupled to the lower portion of the drive shaft, the fan including
 a main body having a plurality of fan blades, 
 an upper counterweight located on one side of the main body and a lower counterweight located on an opposite side of the main body for balancing the operation of the fan, and 
 an interruption region located opposite the lower counterweight, wherein the fan blades located within the interruption region have a reduced mass; and 
 
   a baseplate for selectively mounting a sanding sheet, the baseplate being coupled to the lower portion of the drive shaft for orbital rotation about the rotational axis.   
     
     
         2 . The orbital sander of  claim 1 , further comprising
 a motor housing for housing the electric motor;   a battery receptacle for selectively receiving a battery pack to provide electrical power to the motor; and   a dust collection portion integrated with the housing for partially housing a dust collection system.   
     
     
         3 . The orbital sander of  claim 2 , further comprising
 a paper retention system including
 a front clamp supported on the baseplate, and 
 a rear clamp supported on an opposite side of the baseplate as the dust collection portion. 
   
     
     
         4 . The orbital sander of  claim 1 , wherein the fan blades located within the interruption region have a height of 1 millimeter. 
     
     
         5 . The orbital sander of  claim 2 , wherein the dust collection system includes a shroud portion for partially enclosing the fan blades to form a seal between the housing and the fan blades, and a mating interface having a latch for selectively receiving a dust bag attachment. 
     
     
         6 . The orbital sander of  claim 5 , wherein the dust collection system further includes a latching mechanism that hooks onto the latch on the mating interface to selectively secure the dust bag attachment. 
     
     
         7 . The orbital sander of  claim 3 , wherein the paper retention system further includes one or more stop features mounted to the baseplate for preventing flexion of the front clamp. 
     
     
         8 . The orbital sander of  claim 2 , wherein the battery receptacle defines a battery insertion axis, and wherein the battery pack receptacle includes a lower portion that defines a plane obliquely oriented with respect to the battery insertion axis to create a gap between the battery pack and the battery receptacle when the battery pack is mounted to the battery receptacle, the plane and battery insertion axis defining therebetween an included angle between 0 and 10 degrees. 
     
     
         9 . An orbital sander comprising:
 a housing;   a drive unit within the housing, the drive unit including
 an electric motor defining a rotational axis, 
 a drive shaft coupled for co-rotation with the motor about the rotational axis, 
   the drive shaft including a lower portion, and
 a fan rotatably coupled to the lower portion of the drive shaft; and 
   a dust collection portion integrated with the housing for partially housing a dust collection system, the dust collection system including
 a shroud portion for partially enclosing the fan to form a seal between the housing and the fan, 
 a mating interface having a latch for selectively receiving a dust bag attachment, and 
 a latching mechanism for hooking onto the latch to secure the dust bag attachment; and 
   a baseplate for selectively mounting a sanding sheet, the baseplate being coupled to the lower portion of the drive shaft for orbital rotation about the rotational axis.   
     
     
         10 . The orbital sander of  claim 9 , wherein the seal creates a vacuum effect routing dust particles along a dust path through the interface and into the dust bag attachment. 
     
     
         11 . The orbital sander of  claim 9 , further comprising
 a motor housing for housing the electric motor; and   a battery receptacle for selectively receiving a battery pack to provide electrical power to the motor.   
     
     
         12 . The orbital sander of  claim 9  further comprising:
 a paper retention system including
 a front clamp supported on the baseplate, and 
 a rear clamp supported on an opposite side of the baseplate as the dust collection portion. 
 
 
     
     
         13 . The orbital sander of  claim 9 , wherein the fan further includes a main body having a plurality of fan blades, an upper counterweight located on one side of the main body and a lower counterweight located on an opposite side of the main body for balancing the operation of the fan, and an interruption region located opposite the lower counterweight, and wherein the fan blades located within the region have a reduced mass. 
     
     
         14 . The orbital sander of  claim 12 , further comprising
 a foam pad attached to the baseplate for supporting the sanding sheet, wherein the foam pad extends beyond one or more sides of the baseplate acting as a buffer between the baseplate and a work surface.   
     
     
         15 . The orbital sander of  claim 13 , wherein the fan blades located within the interruption region have a height of 1 millimeter. 
     
     
         16 . An orbital sander comprising:
 a housing;   a drive unit within the housing, the drive unit including
 an electric motor having a motor shaft extending from the motor, 
 a drive shaft coupled to the motor and offset from the motor shaft, the drive shaft defining a rotational axis and including a lower portion, and 
 a fan rotatably coupled to the lower portion of the drive shaft, the fan including 
   a main body having a plurality of fan blades;   an upper counterweight located on one side of the main body and a lower counterweight located on an opposite side of the main body for balancing the operation of the fan; and   a baseplate for selectively mounting a sanding sheet, the baseplate being coupled to the lower portion of the drive shaft for orbital rotation about the rotational axis.   
     
     
         17 . The orbital sander of  claim 16 , further comprising
 a first pulley rotatably driven by the motor shaft;   a second pulley coupled to the drive shaft oriented parallel to the first pulley; and   a belt extending between the first and second pulleys for transmitting torque from the motor shaft to the drive shaft.   
     
     
         18 . The orbital sander of  claim 16 , wherein the fan further includes an interruption region located opposite the lower counterweight, and wherein the fan blades located within the interruption region have a reduced mass. 
     
     
         19 . The orbital sander of  claim 16 , further comprising
 a motor housing for housing the electric motor; and   a battery receptacle for selectively receiving a battery pack to provide electrical power to the motor.   
     
     
         20 . The orbital sander of  claim 19 , wherein when the battery pack is mounted to the battery receptacle, the center of gravity is located substantially over a center of the baseplate.