Patents by Inventor Claes I. Helgesson

Claes I. Helgesson 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).

  • Additive for concrete
    Patent number: 4144086
    Abstract: Concrete products having a high strength after a short hardening time are manufactured by adding sodium sulphate to a conventional concrete mixture in a quantity of 0.1 - 5 per cent by weight of the cement. The concrete shall be kept at a temperature of 30.degree.- 90.degree. C. during the mixing process. The cast concrete shall be held at 30.degree.- 90.degree. C. for at least two hours.
    Type: Grant
    Filed: September 12, 1977
    Date of Patent: March 13, 1979
    Assignee: AB Alfong Betonghardningsmedel
    Inventor: Claes I. Helgesson
  • Method and apparatus for biological purification
    Patent number: 4088571
    Abstract: The invention relates to a method and an apparatus for biological purification in accordance with liquid wastes, the purification being achieved by means of micro-organisms on an inert carrier. The improvement of the invention comprises using a carrier, the surface layer of which comprises colloidal silica. The invention also relates to a method of imparting bacteriophilic properties to a silicious material which comprises preparing a layer of colloidal silica thereupon.
    Type: Grant
    Filed: February 9, 1976
    Date of Patent: May 9, 1978
    Assignee: Arbman Development AB
    Inventor: Claes I. Helgesson