Patents Assigned to Hobas Engineering AG, S.A. Ltd.
  • Patent number: 4167953
    Abstract: A reinforced tube or a tubular pipe comprises an inner tubular first layer of glass fiber reinforced plastic, an outer tubular second layer disposed around and spaced radially outwardly from the first layer and also comprising a glass fiber reinforced plastic, and an intermediate filler layer located between the first and second layers and containing plastic and granular filler material which is bonded together and to said first and second layer. In addition a reinforcing insert is embedded in the intermediate filler layer and it comprises a continuous coil wound around the first layer and embedded in the intermediate layer. The coil may comprise a fiber reinforced plastic coil or a steel wire coil and a single one or two concentrically arranged coils may be embedded in the filler layer. The filler layer comprises plastic bonded granular material such as plastic and sand or an insulating material which may be made of an epoxy or a diphenyl polyester resin.
    Type: Grant
    Filed: April 28, 1976
    Date of Patent: September 18, 1979
    Assignee: Hobas Engineering AG, S.A. Ltd.
    Inventor: Borge I. Carlstrom