Patents by Inventor Rolf E. Lindqvist

Rolf E. Lindqvist 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).

  • Reversible plow
    Patent number: 4316507
    Abstract: A frame of a reversible plow having plow shares that are directed to the right and to the left. The frame is turned by means of a piston connected to a turning shaft of the frame, the turning of the cylinder being controlled by an automatic reversing valve. The valve has a fixed housing and a movable shaft. Peripheral grooves are present in either the housing or shaft through which hydraulic oil is supplied from one side of the piston to the other side thereof.
    Type: Grant
    Filed: April 24, 1980
    Date of Patent: February 23, 1982
    Assignee: Aktiebolaget Overums Bruk
    Inventor: Rolf E. Lindqvist
  • Coulter
    Patent number: D260264
    Type: Grant
    Filed: July 17, 1978
    Date of Patent: August 18, 1981
    Assignee: Aktiebolaget Overums Bruk
    Inventors: Erik H. Carlsson, Rolf E. Lindqvist