| 主权项 |
1. A screw driving device with adjustable countersink depth, comprising:
a drive shaft having a drive end adapted to be engaged and driven by a power tool and a socket end with an annular wall that forms a socket which receives and retains a screw bit, the annular wall having a plurality of radial through bores which respectively receive a clutch ball bearing that engages the screw bit in a drive position and disengages the screw bit in a clutched position; a hollow clutch sleeve having a top end, a bottom end and a central passage that receives the drive shaft, a top end of the central passage being sized to permit the drive end of the drive shaft to pass there through, but not permit the socket end of the drive shaft to pass there through, the hollow clutch sleeve having an annular groove in a bottom end of the central passage sized to receive the respective clutch ball bearings when the drive shaft is in the clutched position so that the clutch ball bearings disengage the screw bit but remain captured in the respective radial through bores, and further having a pin thread on an outer surface of the bottom end and at least two spaced-apart detents located above the pin thread; and a resilient depth adjustment sleeve that surrounds the bottom end of the hollow clutch sleeve, the resilient depth adjustment sleeve having a bottom end with a passage through which the screw bit extends and a box thread above the passage that engages the pin thread on the hollow clutch sleeve, and further having a plurality of elongated stop grooves, each of the stop grooves being respectively sized to engage one of the detents on the outer surface to the hollow clutch sleeve, so that rotational force applied to the resilient depth adjustment sleeve deforms the resilient depth adjustment sleeve to permit ridges between the respective stop grooves to pass over the detents to change a depth to which a screw is driven by the screw bit before the drive shaft reaches the clutched position. |
