Four position valve assembly

摘要

A hydraulic power circuit for operating hydraulic motors at several speeds includes first and second fluid sources and a valve assembly for combining flow from the second source with flow from the first source as a faster motor speed is required. The valve assembly includes a first valve controlling the flow of fluid from the first source to the motors while a slow motor speed is required. The valve assembly also includes a fluid actuated valve controlling the flow of fluid from the second source to the motors as a faster motor speed is required. The fluid actuated valve is actuated by flow from the first source through metering ducts. Once the fluid actuated valve is actuated, fluid from the second source is mixed with fluid from the first source and the valve assembly communicates the increased flow to the motors thus obtaining a faster motor speed.