Patents by Inventor David Twell

David Twell 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: 4264023
    Abstract: Mechanism for dispensing seed or fertilizer for agricultural row crop implements such as seed drills and precision planters. A resilient rotatable roller cooperates with a flat vertical glass dispensing plate to dispense seed or fertilizer from a hopper through a nip between the plate and the roller. A slightly raised narrow slow rate band on the roller cooperates sealingly with a pair of removable confinement flanges so that small seeds such as kale can be confined to the slow rate band and dispensed much more slowly than if the whole width of the roller were used.
    Type: Grant
    Filed: May 16, 1979
    Date of Patent: April 28, 1981
    Assignee: Hestair Farm Equipment Limited
    Inventors: Richard A. Stocks, David Twell
  • Patent number: 4259912
    Abstract: A mechanism for dispensing seed or fertilizer, etc., for agricultural row crop implements such as seed drills and precision planters, comprises a resilient rotatable roller which cooperates with a flat vertical glass dispensing plate to dispense seed or fertilizer from a hopper through a nip between the plate and the roller. The roller is of unfoamed polyurethane formed with a honeycomb of axially extending recesses defining a relatively thin outer deflection band of the roller. The recesses give the roller the uniform and high degree of flexibility needed to accommodate a wide range of seed sizes while retaining the durability, consistency of physical characteristics and suitability for precision moulding, of unfoamed polyurethane.
    Type: Grant
    Filed: May 16, 1979
    Date of Patent: April 7, 1981
    Assignee: Hestair Farm Equipment Limited
    Inventors: Richard A. Stocks, David Twell