Patents by Inventor David W. MacDonald

David W. MacDonald 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).

  • Apparatus and Methods for Interconnecting Tubular Sections
    Publication number: 20100193981
    Abstract: Apparatus and methods for multi-piece tubing are disclosed. Optional nestable embodiments (12, 14, 16, and 18) provide benefits in storage, transportation, and use. Optional interlocking elements (30, 32) provide benefits in ease of assembly and use, and possible disassembly, including with other tubing or non-tubing elements such as a base (20). End cover elements (19) can protect tube's interior from undesired dirt, liquid, or other contaminants, and can be removable. Methods include use in forming concrete pier footings or other building supports.
    Type: Application
    Filed: September 21, 2007
    Publication date: August 5, 2010
    Inventors: Frano Luburic, David W. MacDonald
  • Apparatus and methods for interconnecting tubular sections
    Patent number: D667567
    Type: Grant
    Filed: May 4, 2012
    Date of Patent: September 18, 2012
    Assignee: Ropak Corporation
    Inventors: Frano Luburic, David W. MacDonald