Patent ID: 9102026
Filing Date: 2015-08-11
Classification: B23B,B23Q,Y10T

Abstract:
1. A device for measuring the depth of a through-hole formed through one or more workpieces, the device comprising: a cutting force sensor configured and mountable in a position to sense cutting force exerted by a drill bit of a drill against a workpiece or stack of workpieces; a workpiece near-side surface position sensor comprising a pressure foot supported for reciprocal motion along a pressure foot axis, and further comprising a pressure foot axis position sensor configured to sense the position of the pressure foot along the pressure foot axis; a workpiece far-side surface position sensor; and a controller coupled to the cutting force sensor, coupleable to the pressure foot axis position sensor and the far-side position sensor, and configured to record a through-hole depth of a workpiece or stack of workpieces as being the difference between a workpiece near-side surface position indicated by the pressure foot axis position sensor and a workpiece far-side surface position indicated by the far-side position sensor when the controller receives a decaying force signal from the force sensor indicative of drill bit breakout.