Power drill and automatic control system therefore

A power drill and control therefore comprising:

• (a) a drill spindle means including a spindle member for mounting a rotary cutter on said drill spindle means;
• (b) a spindle rotation drive means including a compressed air powered drive motor having a rotatable output shaft and an associated rotation drive mechanism operably connected between said motor shaft and said spindle means to rotate said spindle member;
• (c) a spindle feed drive means including a compressed air powered feed motor having a rotatable output shaft and an associated feed drive mechanism operably connected between said motor shaft and said spindle means to convert rotational movement in said drive means to reciprocal movement and to feed said spindle member in a forward direction toward a workpiece and in a retract direction away from a workpiece;
• (d) means to stop and start said drive motor and said feed motor independently;
• (e) means with said spindle rotation drive means to vary the rotational speed of said spindle member;
• (f) means with said spindle feed drive means to vary the rate of feed of said spindle member;
• (g) means with said spindle rotation drive means to sense the operational torque of said spindle member;
• (h) means with said spindle drive means to sense thrust force on said spindle member and on an associated cutter;
• (i) means with said spindle rotation drive means to sense and monitor the spindle drive rotation;
• (j) means with said spindle feed drive means to sense and monitor the feed drive rotation;
• and
• (k) control means operably connected with said above plurality of means to control the rotational speed of said spindle means, the rate of feeding motion of said spindle means, and the displacement of said spindle member to place an associated cutter at a predetermined depth and additionally to control removing of the associated cutter from the workpiece upon completion of the drilling operation.