Electronic micro-stop/tool failure monitor

• US 5,161,922 A
• Filed: 12/11/1990
• Issued: 11/10/1992
• Est. Priority Date: 12/11/1990
• Status: Expired due to Fees

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Malloy, Joseph P.
• Primary Examiner(s): Howell, Daniel W.
• Application Number:
  US07/625,518
• Time in Patent Office: 700 Days
• Field of Search: 408/5, 408/6, 408/10, 408/11, 408/12, 408/14, 408/16, 408/13, 324/207.16, 324/207.22, 324/207.26, 324/226, 324/234, 324/236, 324/239, 324/261, 324/262, 324/263
• US Class Current: 408/14
• CPC Class Codes: B23B 2270/32 Use of electronics
• CPC Class Codes: B23B 49/001 Devices for detecting or indicating failure of drills
• CPC Class Codes: B23B 49/006 Attached to drilling machines
• CPC Class Codes: B23Q 15/24 of linear position
• CPC Class Codes: G05B 2219/35512 Display entered, measured values with bargraph
• CPC Class Codes: G05B 2219/37245 Breakage tool, failure
• CPC Class Codes: G05B 2219/37292 Eddy current
• CPC Class Codes: G05B 2219/37425 Distance, range
• CPC Class Codes: G05B 2219/45129 Boring, drilling
• CPC Class Codes: Y10T 408/18 with stopping upon completion of prescribed operation
• CPC Class Codes: Y10T 408/21 with signal, indicator, illuminator or optical means

Abstract

Electronic measuring and control of countersinking depth and/or failure of a drilling tool. Eddy current proximity detecting means is utilized for stopping and retracting the countersink drilling process after a pre-selected depth is achieved wherein a visual indication of the countersink depth is provided by way of sequentially lit LED segments through structure for detecting a surface up and away from the working end of the tool thereby avoiding contamination problems. Further, detection of vibration or chatter in the workpiece is shown as a means for detecting tool defects.

Claims

1. A system for controlling countersink depth comprising in combination:

a threaded adjusted micro-stop having a rotating shaft and a non-rotating base;

a disk disposed perpendicular to said rotating shaft;

an eddy current device positioned on said non-rotating base of said micro-stop for sensing the advancing position of said disk during countersinking;

a set point controller and relay circuit responsive to the output of said eddy current device;

said set point controller triggering at a predetermined countersink depth for causing a drill feed to stop and retract.

2. The system of claim 1 further including a visual indicator device responsive to the countersink depth.

3. The system of claim 2 wherein said indicator device includes a plurality of LED segments which are illuminated when said predetermined depth is reached providing visual feedback to an operator.