DRILL STAND

PURPOSE: To secure protection to a boring tool by composing coupling of a drill machine and/or a holder with a feed drive in such a way that the drill machine and/or the holder is capable of making relative motion to the feed drive in the opposite direction to the feed direction against reaction force, and monitoring the relative motion by a switch element. CONSTITUTION: When lowering motion is made till a drilling head 19 meets an excessive resistance or till a drill machine 18 is applied to a stopper, a rack 24 slides relatively downward to a holder 16 till a screw 27 gets in contact with an upper end of a rectangular pile 26. Simultaneously, an upper stopper 48 slides down in a cavity 50, when lower packing material of a packing 52 is compressed. A bolt 54 supported by an upper stopper bolt 48 simultaneously slides down in a vertical hole in the cavity 50 to cause change of opened/closed conditions of a switch 56, while simultaneously resulting in stoppage of a feed drive and a drive pinion 23.