Power tool having tool-free attachment system

Abstract

The present invention provides a grinder including a housing, a drive assembly within the housing including an electric motor having a motor shaft, and an output spindle coupled to the motor shaft for rotatably driving a grinding tool. The grinder further includes a tool-free attachment mechanism for selectively mounting the grinding tool to the output spindle for co-rotation therewith including a flange nut threaded to the output spindle, and a backing flange axially movable along the output spindle between a first position, in which a space exists to position the grinding tool between the flange nut and the backing flange, and a second position, in which the grinding tool is clamped between the backing flange and the flange nut.

1 . A grinder comprising:
 a housing;   a drive assembly within the housing, the drive assembly including
 an electric motor having a motor shaft, and 
 an output spindle coupled to the motor shaft for rotatably driving a grinding tool; and 
   a tool-free attachment mechanism for selectively mounting the grinding tool to the output spindle for co-rotation therewith, the attachment mechanism including
 a flange nut threaded to the output spindle, and 
 a backing flange axially movable along the output spindle between a first position, in which a space exists to position the grinding tool between the flange nut and the backing flange, and a second position, in which the grinding tool is clamped between the backing flange and the flange nut. 
   
     
     
         2 . The grinder of  claim 1 , further comprising:
 a battery receptacle; and   a battery pack selectively electrically coupled to the battery receptacle to provide electrical power to the motor.   
     
     
         3 . The grinder of  claim 1 , wherein each of the flange nut and the backing flange cooperatively defining a first mounting arrangement, and wherein the grinding tool includes a second mounting arrangement configured to receive therethrough the first mounting arrangement. 
     
     
         4 . The grinder of  claim 3 , wherein, when the grinding tool is mounted to the spindle, the grinding tool is rotated to misalign the second mounting arrangement from the first mounting arrangement on the flange nut, and to align the second mounting arrangement with the first mounting arrangement on the backing flange to rotationally lock the grinding tool on the spindle. 
     
     
         5 . The grinder of  claim 3 , wherein the first mounting arrangement includes a first plurality of axially extending protrusions and the second mounting arrangement includes a second plurality of radially extending protrusions that are configured to misalign with the first plurality of axially extending protrusions of the first mounting arrangement. 
     
     
         6 . The grinder of  claim 4 , wherein the grinding tool includes an aperture having a plurality of recesses configured to fit over the first mounting arrangement and the second mounting arrangement. 
     
     
         7 . The grinder of  claim 6 , wherein the backing flange is configured to move along the spindle to create a space between the backing flange and the flange nut in which the grinding tool is installed. 
     
     
         8 . The grinder of  claim 7 , wherein the grinding tool is locked with the space by misaligning the first mounting arrangement with the second mounting arrangement. 
     
     
         9 . A grinder comprising:
 a housing;   a drive assembly within the housing, the drive assembly including   an electric motor having a motor shaft, and   a hollow output spindle coupled to the motor shaft for rotatably driving a grinding tool, the spindle including a backing flange portion at one end thereof; and   a tool-free attachment mechanism for selectively mounting the grinding tool to the output spindle for co-rotation therewith, the attachment mechanism including
 a clamping shaft extending through the spindle having a flange nut portion and a stem portion extending from the flange nut portion, and 
 a handle pivotably coupled to the housing between a release position, in which the flange nut portion is displaced from the backing flange portion to create a space for mounting the grinding tool between the flange nut portion and the backing flange portion, and a clamped position, in which the grinding tool is clamped between the backing flange portion and the flange nut portion. 
   
     
     
         10 . The grinder of  claim 9 , wherein each of the flange nut portion and the backing flange portion includes a first mounting arrangement, and wherein the grinding tool includes a second mounting arrangement configured to receive therethrough the first mounting arrangement of the flange nut portion and the backing flange portion. 
     
     
         11 . The grinder of  claim 10 , wherein, when the grinding tool is mounted to the spindle, the grinding tool is rotated to misalign the second mounting arrangement from the first mounting arrangement on the flange nut portion, and to align the second mounting arrangement with the first mounting arrangement on the backing flange portion to rotationally lock the grinding tool on the spindle. 
     
     
         12 . The grinder of  claim 10 , wherein the first mounting arrangement includes a plurality of axially extending protrusions. 
     
     
         13 . The grinder of  claim 12 , wherein the second mounting arrangement includes a plurality of radially extending protrusions that are configured to misalign with and be received between the plurality of axially extending protrusions of the first mounting arrangement. 
     
     
         14 . A grinder comprising:
 a housing;   a drive assembly within the housing including an electric motor having a motor shaft, and an output spindle coupled to the motor shaft for rotatably driving a grinding tool; and   a tool-free attachment mechanism for selectively fastening the grinding tool to the lower portion of the output spindle, the tool-free attachment mechanism including
 a flange nut affixed adjacent an end of the output spindle; 
 an intra flange adjacent the flange nut and configured to rotate relative to the spindle; 
 a backing flange at least partially fitting over the intra flange and biased toward the flange nut, 
 wherein the intra flange includes a structure that at least partially nests in the backing flange, and 
 wherein the intra flange is rotatable between a locked position to lock the grinding tool on the spindle and an unlocked position to unlock the grinding tool from the spindle. 
   
     
     
         15 . The grinder of  claim 14 , wherein the structure comprises a ramp structure and wherein in the locked position the ramp structure fits into a ramp groove formed in the backing flange and the backing flange is biased toward the flange nut. 
     
     
         16 . The grinder of  claim 15 , wherein in the unlocked position the ramp structure is moved out of the ramp groove and lifts the backing flange away from the flange nut and compresses the spring. 
     
     
         17 . The grinder of  claim 14 , wherein the spindle includes a flat region and the backing flange is keyed to the flat region, and wherein the backing flange is fixed radially on the spindle and rotates with the spindle. 
     
     
         18 . The grinder of  claim 17 , wherein the tool-free attachment mechanism further includes a spacer that is keyed to the flat region of the spindle and is fixed radially on the spindle and rotates with the spindle. 
     
     
         19 . The grinder of  claim 18 , wherein the tool-free attachment mechanism further includes a spring installed between the spacer and the backing flange to bias the backing flange toward the flange nut. 
     
     
         20 . The grinder of  claim 17 , wherein the spindle further comprises a shoulder adjacent the flat region to supper the backing flange and limit linear movement of the backing flange along the spindle.