US 4,642,618 A · Tool failure detector

Abstract

A failure detector detects breakage in a machine tool cutting element, such as a drill bit, by use of a accelerometer supported against a workpiece being operated on by the cutting element. Vibrations are induced in the workpiece by the cutting operation, the vibrations having spectral components in the audio frequency range which are characteristic of proper operation of the cutting element, the spectral components changing upon a breakage of the cutting element. A voltage produced by a positioning mechanism of the cutting element identifies the location of the cutting element relative to the workpiece. A bandpass filter separates the spectral components associated with proper operation from spectral components associated with faulty operation. Logic circuitry signals the joint occurrence of the spectral components of proper operation with the position of the cutting element at the site of the workpiece so as to permit the signaling of a cutting tool failure during operation on the workpiece.

Claims14

Dependent claims

A tool failure detection system for use with machinery comprising a tool ;

means for supporting a workpiece in an operating region of said tool;
and means for advancing said tool toward said workpiece for operating thereon and for providing a signal indicating position of the tool, an operation of said tool upon the workpiece inducing vibrations characteristic of said operation;
said
means for sensing said vibrations;
means coupled to said sensing means for analyzing said vibrations to determine proper operation of said tool, said analyzing means including means responsive to the position signal for designating when the tool is to be engaged with the workpiece;
and
means coupled to said analyzing means for indicating a failure in the operation of said tool.

4 more elements

A tool failure detection system for use with machinery comprising a tool;

means for supporting a workpiece in an operating region of said tool;
and means for advancing said tool towards said workpiece for operating thereon, an operation of said tool upon the workpiece inducing vibrations characteristic of said operation;
said failure detection system comprising:
means for sensing said vibrations;
means coupled to said sensing means for analyzing said vibrations to determine proper operation of said tool;
means coupled to said analyzing means for indicating a failure in the operation of said tool;
and wherein
said analyzing means is responsive to a time of occurrence of said vibrations;
said advancing means provides a position signal indicative of tool position during an advancement of said tool toward said workpiece;
and wherein
said analyzing means includes a window comparator means responsive to said position signal for designating an interval of time when said tool is to be engaged with the workpiece, said comparator means providing a time signal indicative of an interval of time when said tool is to be engaged with the workpiece.

8 more elements

Dependencies are inferred from the claim text.

Tool failure detector

Life of this patent

Tool failure detector

Life of this patent

Abstract

Claims14