Automatic countersink depth control tool for fastener installer

Abstract

An automatic countersink depth control tool and a combination of the same with an installer for fasteners having countersink heads. The tool has a nonrotatable stop (76) for limiting the depth of a countersink drilled in a fastener hole. The stop (76) is adjustably movable toward or away from a workpiece in which the countersink is to be drilled, the movement of the stop being relative to the depth of the countersink. There is a rotatable screw gear (50) having an external ring gear (54) for moving the stop in accordance with the depth of the countersink and in accordance with the height of the head of the countersink head of the fastener to be installed in the hole. There is a motor (90) having a spur gear (94) engaged with the ring gear (54) to rotate it a predetermined amount by a threaded engagement of the screw gear (50) and the stop (76). Because the stop is nonrotatable, the rotation of the threads moves the stop the desired amount. There is a pressure foot surface (110) associated with a fastener installer to receive the stop (76) in abutment after it has been adjustably moved in accordance with the height of the countersink head to control the depth of the countersink being drilled. As the stop is being moved toward abutment with the pressure foot (110) the countersink drilling occurs and the drilling is completed and stopped when the abutment occurs. The tool adjusts the countersink depth for each individual fastener, measured previously on a head height checker.