Abstract: An apparatus for driving and braking a cutting blade of a lawn mower is disclosed. The apparatus includes a shaft for rotating the blade, and a pulley driven by the engine. The shaft extends through a housing. The apparatus includes means for biasing the pulley toward the housing, and means for translating the pulley away from the housing. The apparatus has a stopped position in which the pulley and housing are in friction contact, and has a cutting position in which the pulley and housing are not in friction contact. When power is delivered from the engine to drive the pulley, the apparatus moves from the stopped position to the cutting position such that the pulley and the housing are not in friction contact and the blade rotates. When power ceases being delivered to the pulley, the apparatus moves from the cutting position to the stopped position such that the pulley and the housing are placed in friction contact and the blade stops.