Patents by Inventor John E. L. Stahl

John E. L. Stahl 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: 4109681
    Abstract: A hoisting crane is of the type comprising a tower and at the top region thereof one inner and one outer jib section which are pivotably mounted. The jib sections have roughly the same length and are by a means slewed relative to the tower, whereby the outer end of the outer jib section -- which carries a hoist controlled lifting hook-- always takes substantially the same level. A pipe for pumping of concrete to a portioning means at the outer end of the outer jib section is attached to the tower and the two jib sections. Rotary couplings are provided coaxial with the pivot axes.
    Type: Grant
    Filed: March 22, 1976
    Date of Patent: August 29, 1978
    Assignee: Tornborg & Lundberg AB
    Inventor: John E. L. Stahl