Drill assembly and method to reduce drill bit plunge
AssigneeQuanser Consulting Inc.
InventorsJ. G. Agop Apkarian, Paul Karam, Don Gardner
Life of this patent
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Abstract
A drill assembly and method for reducing plunge of a drill bit upon breaking through a workpiece. The drill assembly contains a motor to advance and retract the drill bit, the motor is controlled by a control unit in a feedback loop to achieve a desired stiffness. The control unit determines when the drill bit breaks through the workpiece and stops or retracts the movement of the drill bit.
Claims37
A drill assembly comprising:
- a drill body;
- a drill bit rotatably coupled to the drill body;
- a motor for advancing and retracting the drill bit relative to the drill body;
- at least one sensor for monitoring the advancement and retraction of the drill bit;
- and
- a control unit connected to the motor and at least one sensor, the control unit being configured to measure a change in speed of advancing motion of the drill bit relative to the drill body to detect breakthrough of a workpiece and, on detecting a breakthrough, control the motor to reduce plunge of the drill bit.
A method for reducing plunge of a drill bit through a workpiece, the method comprising:
- initiating advancement of the drill bit towards the workpiece;
- and
- detecting the drill bit breaking through the workpiece by measuring a change in speed of advancing motion of the drill bit relative to a drill body.
A method for measuring penetration depth of a drill bit through a workpiece, the method comprising:
- initiating advancement of the drill bit towards the workpiece;
- detecting contact of the drill bit with the workpiece to begin measuring drill bit penetration;
- detecting the drill bit breaking through the workpiece to end measuring drill bit penetration, where the drill breaking through the workpiece is detected by measuring a change in speed of advancing motion of the drill bit relative to a drill body;
- and
- outputting penetration measurement to a display.
Dependencies are inferred from the claim text.