Drill break-through sensor
AssigneeNorthrop Corporation
InventorsHorst W. Neu, Thomas Gilmore, Farrell A. McCann
Life of this patent
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Abstract
An improved power drill having means for sensing when the drill bit has penetrated through the workpiece and for then retracting the drill bit from the workpiece. An electrical signal responsive to the axial force between the drill and the drill bit is used to sense when the drill bit pierces the workpiece. A sudden decrease in the axial force triggers a mechanism for retracting the drill bit from the workpiece. Means are included to detect broken bits, missing bits and previously drilled holes.
Claims4
An improved power drill of the type having means for rotating a drill bit, advancing and retracting means for advancing the drill bit into a workpiece and retracting the drill bit from the workpiece, wherein the improvement comprises:
- (a) sensing means located on the drill side of the workpiece for sensing when the drill bit is encountering resistance from the workpiece;
- and
- (b) control means connected to the sensing means for causing the advancing and retracting means to operate to advance the drill bit so as to bring the drill bit into contact with the workpiece, and to continue to advance the drill bit into the workpiece, and to retract the drill bit from the workpiece when the sensing means has sensed that the drill bit has ceased to encounter resistance from the workpiece.
Dependencies are inferred from the claim text.