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Pressure Sensing Drill Chuck

IP.com Disclosure Number: IPCOM000037096D
Original Publication Date: 1989-Nov-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Adams, GE: AUTHOR

Abstract

An automatic machine drill chuck design is shown which indicates to the machine operator when the drill in the chuck is dull and needs to be changed.

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Pressure Sensing Drill Chuck

An automatic machine drill chuck design is shown which indicates to the machine operator when the drill in the chuck is dull and needs to be changed.

When automatic machines are used for drilling holes, a drill bit may become dull and break without giving the machine operator any indication of a pending failure. Often the part being drilled must be scrapped as a result. A new drill chuck design will give the machine operator an early warning of a dull drill condition in time for the operator to replace or sharpen the drill before a failure occurs.

A dull drill bit requires more pressure than a sharp drill bit when performing a drilling operation. By utilizing a non-contact measurement transducer such as the one manufactured by the Electro Corporation, and a spring that carries a certain spring rating, a drill chuck design is shown that indicates the condition of the drill bit in use. For example, a .020" diameter drill bit requires a 7.2-inch pound spring at a feed rate of .0002" per revolution of the bit when sharp without collapsing the spring. A dull drill bit will cause the spring to collapse and result in a small movement which is picked up by the measurement transducer. Spring adjustments may have to be made with a change in drill size.

Referring to the figure, a cross-section of the pressure sensing drill chuck assembly is shown along with a voltmeter used to indicate to the operator the condition of the drill in use. The trans...