Abstract: A belt-driven transmission designed particularly for self-propelled, walking lawn mowers is provided. The transmission is mounted on a deck of a mower between a front pair or a rear pair of wheels and is driven through a pulley on the engine drive shaft and a pulley on the transmission connected by a belt. With this arrangement, the engine requires no special power take-off shaft to drive the mower. Consequently, the transmission can be universally applied to many different self-propelled lawn mowers. The new transmission can also be equipped with a deadman's clutch. Further, it can be provided with a manually-adjustable pulley of variable diameter to provide different speeds and torque for the drive shaft of the driven wheels. Also, in accordance with the invention, the drive shaft has a ratchet coupling device near each driven wheel to provide a differential effect for the wheels when the mower is being turned.

Abstract: A safety system for a lawn mower is provided for disengaging the blade from the drive when the mower is backing up. The safety system includes a gear which rotates with a wheel of the mower and a toothed member engagable with the gear. When the mower backs up and the gear rotates in one direction, it engages the toothed member and moves it from a first to a second position. A linkage connected with the toothed member and a clutch in the drive train then disengages the clutch and disconnects the mower blade from the drive. When the mower moves forwardly again, the toothed member is moved by the gear back to the first position and the linkage moves the clutch to its engaged position again to rotate the blade by the drive, assuming the shift lever is in its engaged position.