Abstract: A shift dog for an in-line transmission is provided to engage and disengage rotatable members or gears in the transmission. The shift dog has resiliently-mounted teeth which can yield if the teeth are not properly aligned with recesses in the gear when the dog is attempted to be moved into engagement therewith. The transmission can then be shifted through that gear to another position, and particularly to neutral, even though the dog and gear are not aligned for engagement.

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.

Abstract: A riding vehicle, such as a lawn mower, has a flexible apron positioned behind the rear wheels with a lower edge of the apron above the ground. The mower can back up without impediment from the apron, unless an object is encountered. In that case, the object contacting the apron pushes it against the rear wheels and the apron is pulled under the tires where it abruptly snubs the tires and prevents further backing motion. To achieve this, the apron is supported by the mower through yieldable means which holds the apron above the ground until it contacts the wheels. The apron is also anchored to the mower to limit the extent of downward movement of the apron. In a preferred form, the yieldable supporting means for the apron also is resilient so that the apron can be returned to the original position after it is released from the rear wheels, as by driving the mower forwardly again. The apron is capable of stopping the mower securely and abruptly and reliably does so in a fixed, relatively short distance.