Patents by Inventor Helen Dukes

Helen Dukes 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).

  • Air filter
    Patent number: 7285157
    Abstract: An air-filter for a circulating and/or recirculating air system using a filter medium containing a microbiologically effective amount of a polymeric biguanide or salt thereof. Also claimed is a method for reducing odors and/or air-borne micro-organisms in a circulating or recirculating air system using the air-filter, and a method for protecting an air-filter medium against microbial degradation by incorporating in, or on, the medium a microbiologically effective amount of a polymeric biguanide or salt thereof.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: October 23, 2007
    Assignee: Arch UK Biocides Limited
    Inventors: Helen Dukes, John David Payne