On-Board Auxiliary Hydraulic Systems

Abstract

The power steering pump of a vehicle powers an auxiliary hydraulic system of the vehicle only when the vehicle is parked.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an electro-hydraulic schematic of an on-board vehicle hydraulic system of the invention.

Claims

1. In an auxiliary hydraulic system for a vehicle that is operable to actuate one or more auxiliary hydraulic devices on board the vehicle that are only operable when the vehicle is not being driven, the vehicle having an engine that is engageable with wheels of the vehicle to propel the vehicle and a hydraulic power steering pump that is driven by the engine and supplies fluid under pressure to a power steering system of the vehicle when the vehicle is in transit, the improvement wherein the power steering pump provides a source of hydraulic fluid under pressure to power the auxiliary hydraulic system and is operable to power said system only when the vehicle is parked.

2. The improvement of claim 1, wherein the system senses whether the vehicle is parked by determining if it is in neutral with the parking brake on.

3. The improvement of claim 1, wherein the vehicle has an automatic transmission and the system senses whether the vehicle is parked by determining if the transmission is in park.

4. The improvement of claim 1, wherein the system is a vehicle leveling system.

5. The improvement of claim 1, wherein the system is a slide-out system.

6. The improvement of claim 1, wherein the vehicle is a recreational vehicle.

7. The improvement of claim 1, wherein when the vehicle is parked the power steering pump does not provide fluid under pressure to the power steering system unless there is excessive flow from the pump that is not needed by the auxiliary hydraulic system.

8. The improvement of claim 1, wherein the auxiliary hydraulic system has a return line that is separate from a return line of the power steering system.

9. The improvement of claim 1, wherein the system alerts the operator of a low volume of hydraulic fluid in the system.