Patents by Inventor Dafydd Williams Evans

Dafydd Williams Evans 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).

  • Patent number: 4008571
    Abstract: An energy conserving hydraulic system for a lift truck or the like including a hydraulic tilt cylinder and a hydraulic lift cylinder subject to varying load requirements, manually operable valves for controlling the cylinders, a first, high volume hydraulic pump, a second, low volume hydraulic pump, a reversible, bidirectional DC motor for simultaneously driving both the pumps, and a piping system connecting the pumps to the valves such that for one direction of drive of the motor, the first pump will deliver a high volume of hydraulic fluid to the valve for operation of the lift cylinder, and for the other direction of drive of the motor, the first pump will be unloaded. A conduit is also arranged such that for the other direction of drive, the second pump will deliver a low volume of hydraulic fluid to the valve for directing the same to the tilt cylinder. An electrical direction control for controlling the direction of drive is responsive to the valves.
    Type: Grant
    Filed: March 31, 1976
    Date of Patent: February 22, 1977
    Assignee: Towmotor Corporation
    Inventor: Dafydd Williams Evans