Patent ID: 7200982

Claim:
A vegetation cutting device comprising: a prime mover including an output shaft having a central axis; a blade drivably coupled to the output shaft, the blade having a longitudinal axis; and a slippage apparatus drivably coupling the output shaft and the blade, the slippage apparatus including an insert including an aperture to receive the output shaft; a first key extending toward a central axis of the output shaft that engages a keyway in the output shaft; a second key extending away from the central axis of the output shaft; an adapter rotatable with the insert and the blade, the adapter including a bore to receive the insert; a keyway to receive the second key of the insert; and a projection engageable with the blade to align the first key with the longitudinal axis of the blade; wherein the insert is adapted to at least partially crack at a location adjacent the first key when the blade strikes an object.