Abstract: An operation controlling apparatus for a passenger operated machine such as a tractor, snowmobile or the like. The apparatus includes an engine cut-off mechanism which terminates engine operation if an operator is expelled from the machine seat for a pre-determined time. Relatively short, intermittent periods of displacement of an operator from the seat, such as when travelling over rough or bumpy terrain, will not terminate engine operation. After emergency engine stoppage, the apparatus requires the machine be placed in a start waiting state, for instance by disengaging the clutch or when the transmission is placed in neutral, before the engine can be re-started.

Abstract: A control device in a mower in which an engine output is transmitted to a cutter blade through a coupling of a clutch for performing mowing. A blade engagement switch is provided for sending a drive signal for engaging the cutter blade. A first control device receives the signal and electrically increases a degree of opening of a throttle valve of the engine. A second control device is provided for electrially performing coupling and decoupling of the clutch. A first timer circuit actuates the first control device a predetermined period upon closure of the blade engagement switch. A second timer circuit actuates the second control device to provide coupling of the clutch at a predetermined timing within the predetermined period after closure of the blade engagement switch.

Abstract: A set of display wheels are jointly driven from a conventional vehicle odometer so as to complete a revolution each time the vehicle travels a predetermined distance of, for example, 10,000 kilometers. Each display wheel has one or more warning zones on its circumference such that each warning zone, when turned to a display position for observation by the vehicle driver, indicates the fact that some particular part of the vehicle is in need of inspection or servicing. The display device further comprises means for automatically locking any one of the display wheels against rotation when the warning zone thereon turns to the display position, and means for unlocking and resetting the display wheel after the necessary inspection or servicing, as by the depression of a push button.