Patents by Inventor Per S. G. Gustafsson

Per S. G. Gustafsson 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).

  • Hydraulic down-the-hole rock drill
    Patent number: 4660658
    Abstract: Pressurized water is used to operate a percussive down-the-hole drill and the spent motive fluid is used as a flushing fluid. A rear cylinder chamber (24) is constantly pressurized and a valve (28) controls the inlet from the chamber (24) to a bore (23) through the piston hammer (21). A valve (42) controls the outlet from the front cylinder chamber (26) to a flushing channel (38) in the drill bit (21). A check valve (45) controls the outlet from the bore (23) to the front cylinder chamber (26).
    Type: Grant
    Filed: June 18, 1985
    Date of Patent: April 28, 1987
    Assignee: Atlas Copco Aktiebolag
    Inventor: Per S. G. Gustafsson