Patents by Inventor Ian J. C. MacLeod

Ian J. C. MacLeod has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Closed circuit steering circuit for mobile vehicles
    Patent number: 6923289
    Abstract: A closed-circuit pump is provided that receives input from a steering unit in order to drive a steering cylinder. The closed-circuit pump is preferably a proportional bi-directional pump. The steering unit includes a steering wheel or similar device controlled by an operator. In one embodiment, the steering unit is a conventional hydraulic system that includes a servo pump. In another embodiment, the steering unit is an electronic displacement control system. The steering cylinder engages with a steering assembly to perform the steering function by physically turning the wheels of the vehicle. The inlet of the steering cylinder includes a counterbalance valve, which prevents flow into the steering cylinder when there is no steering input from the operator.
    Type: Grant
    Filed: September 11, 2003
    Date of Patent: August 2, 2005
    Assignee: Sauer-Danfoss, Inc.
    Inventors: Ian J. C. MacLeod, Rick J. Sporrer
  • Closed circuit steering circuit for mobile vehicle
    Patent number: 6923290
    Abstract: A closed-circuit pump is provided that receives input from a steering unit in order to drive a steering cylinder. The closed-circuit pump is preferably a proportional bi-directional pump. The steering unit includes a steering wheel or similar device controlled by an operator. In one embodiment, the steering unit is a conventional hydraulic system that includes a servo pump. In another embodiment, the steering unit is an electronic displacement control system. The steering cylinder engages with a steering assembly to perform the steering function by physically turning the wheels of the vehicle. The inlet of the steering cylinder includes a counterbalance valve, which prevents flow into the steering cylinder when there is no steering input from the operator.
    Type: Grant
    Filed: May 27, 2004
    Date of Patent: August 2, 2005
    Assignee: Sauer-Danfoss, Inc.
    Inventors: Ian J. C. MacLeod, Rick J. Sporrer
  • Automatic remote pressure compensation in an open circuit pump
    Patent number: 6874318
    Abstract: An open circuit system that uses a two-position three-way logic valve that automatically compensates for remote pressure in the system. The system has a pump that sends a pump supply through an orifice to the two-position three-way logic valve. Then depending on the load sense signal, the valve either allows the flow of the pump supply to the compensation relief valve or alternatively, the logic valve prevents the flow from the pump supply. The load sensing signal determines whether the valve will allow flow from the pump supply.
    Type: Grant
    Filed: September 18, 2003
    Date of Patent: April 5, 2005
    Assignee: Sauer-Danfoss, Inc.
    Inventor: Ian J. C. MacLeod
  • Closed circuit swing control system
    Patent number: 6520731
    Abstract: A control system for swing cylinders to position a boom on a backhoe or the like includes a pair of double acting hydraulic cylinders on the backhoe frame operatively connected to the boom for swinging the boom with respect to the frame, a closed circuit pump arranged in a closed circuit with the hydraulic cylinders such that the control on the pump is the sole means of controlling the cylinders.
    Type: Grant
    Filed: June 27, 2001
    Date of Patent: February 18, 2003
    Assignee: Sauer-Danfoss, Inc.
    Inventor: Ian J. C. MacLeod
  • Closed circuit swing control system
    Publication number: 20030002972
    Abstract: A control system for swing cylinders to position a boom on a backhoe or the like includes a pair of double acting hydraulic cylinders on the backhoe frame operatively connected to the boom for swinging the boom with respect to the frame, a closed circuit pump arranged in a closed circuit with the hydraulic cylinders such that the control on the pump is the sole means of controlling the cylinders.
    Type: Application
    Filed: June 27, 2001
    Publication date: January 2, 2003
    Inventor: Ian J.C. MacLeod