Patent · US Expired

Hydraulic systems for a small loader

US6662556B2 · kind B2 · utility

22Cited by
5References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 25, 2002
Grant dateDec 16, 2003
Priority date
Expiry dateFeb 25, 2022

Classification

  • Technology area (CPC E)Fixed Constructions
  • CPC primaryE02F9/2292
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A small self-propelled loader has hydraulic drive motors and at least one work cylinder, and has a hydraulic system that efficiently utilizes the available horse power from an internal combustion engine on the loader. The engine drives a tandem pump and the flows from two sections of the tandem pump pass through a first diverter valve that permits using the flow from each of the pump sections to drive a respective one of the drive motors. The return or drain flow from valves controlling the drive motors is connected to a second diverter valve to selectively direct the drain flow from the drive motors for operating remote work cylinders. Alternately, the first diverter valve directs the output from one pump section to the work cylinders, so that when the loader is standing still or moving very slowly, the work cylinder has adequate flow, and flow from the other pump section is split to power the drive motors. The motors and work cylinders are connected to separate relief valves so that a higher working pressure is available for the drive motors.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.