Patents Assigned to Terra AG fuer Tiefbautechnick
  • Patent number: 5695014
    Abstract: A ram boring apparatus has a generally cylindrical body with an attached head, the apparatus being connected to a drive rod which pushes the apparatus forwardly through the earth. The drive rod can also rotate the body and the attached head about the longitudinal axis of the apparatus, and operation of the apparatus can also be supported by the ejection of pressure fluid from one or more jets arranged on the head and by a hammering mechanism carried by a portion of the body. The hammering mechanism is activatable by pressure fluid from the same source as the pressure fluid supplied to the one or more jets. The pressure fluid is delivered through the hollow drive rod and a control valve in a fluid supply line in the body, in dependence on the pressure of the pressure fluid supplied to the apparatus, selectively directs the pressure fluid to the one or more jets in the head or simultaneously to both the one or more jets and to the hammering mechanism.
    Type: Grant
    Filed: September 12, 1995
    Date of Patent: December 9, 1997
    Assignee: Terra AG fuer Tiefbautechnick
    Inventor: Dietmar Jenne