Interlock circuit for a vehicle with an optical second drive
AssigneeDeere & Company
InventorsRudolph A. Peterson, Jr., James J. Cinnamon
Life of this patent
Estimating the term…
Abstract
An interlock circuit is provided for a vehicle having a first PTO shaft and an optional second PTO shaft. When the optional PTO is installed, a standard seat switch utilized with the base interlock circuit is connected to an additional relay to put the interlock into a potential defeat mode as soon as the operator leaves the seat, provided the vehicle parking brake is engaged and a mechanical selector lever is in a position wherein the optional PTO only is selected. Other interlock functions remain unaffected whether or not the optional PTO is installed.
Claims12
In a vehicle having a frame supported for movement over the ground by drive wheels connected through a transmission to an engine, an operator station, a first drive for providing power to a first driven device, an electrically engageable clutch connected between the engine and the first drive, and an operator presence interlock including an operator presence switch providing a first signal when the operator is present at the station and a second signal when the operator is absent from the station, the interlock normally permitting operation of the first drive only when the first signal is present, optional drive and interlock circuit structure comprising:
- a second drive connected to the clutch;
- a drive selector for selectively engaging the first or second drive;
- and
- means responsive to the selection of the second drive for overriding the operator presence interlock under preselected vehicle conditions when the operator is absent from the station.
The invention as set forth in claim i wherein the operator presence interlock includes an override relay connected to the operator presence switch and responsive to the switch being in a state corresponding to the operator being absent from the station for maintaining engine operation only if the first drive is not selected.
In a vehicle having a frame supported for movement over the ground by drive wheels connected through a transmission to an engine, an engageable brake, a source of current, an operator station, a fist selectively operable drive for providing power to a driven device, an electrically engageable clutch connected between the engine and the first drive, a first condition responsive current path connected between the source and the clutch, the fist current path including an operator presence switch having a first condition when the operator is present at the station and a second condition when the operator is absent from the station, means for maintaining the engine in a running condition with the clutch engaged only when the switch is in the fist condition, optional drive and interlock circuit structure comprising:
- a second drive connected to the clutch;
- means for providing a vehicle braked condition indication dependent upon brake engagement;
- a drive selector for selectively engaging the fist or second drive;
- and
- means responsive to the selection of the second drive only for providing a second current path from the source to the engine to maintain the engine in a running condition when the switch is in the second condition, said means responsive including an override relay and mean connecting the override relay to the operator presence switch of establishing the second current path when the operator presence switch is in the second condition only if the vehicle braked condition is indicated.
Dependencies are inferred from the claim text.