Patents by Inventor Ralf G. Andersson

Ralf G. Andersson 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: 4639318
    Abstract: A tubular filter which is primarily intended for filtration of liquid flowing substantially radially towards the interior of the filter. The filter comprises two layers (10, 11) of mineral wool. An interior layer (10) has the fibres oriented substantially concentrically to the tube axis and an outer filter layer (11) of mineral wool has the fibres oriented substantially radially to the tube axis. The material of the tubular filter must be arranged so that its density increases from the outer portion of the tubular filter towards its inner portion.
    Type: Grant
    Filed: November 7, 1984
    Date of Patent: January 27, 1987
    Assignee: Gullfiber AB
    Inventor: Ralf G. Andersson