Patents by Inventor David A. Schaefer

David A. Schaefer 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: 5421621
    Abstract: A slip-type expansion joint including a body portion for connection to a pipe or conduit and having an inner annular recess for receiving packing rings and injectable packing material and the joint further including a slip portion for connection to another pipe or conduit and guidedly received in the body portion for limited axial movement therein to accommodate limited axial movement of the pipes or conduits, the packing rings providing the main sealing function of the joint and the packing material exerting force on the packing rings to maintain the sealing function thereof, the expansion joint characterized by a plurality of ports around the body in communication with the annular recess for introducing the packing material to the recess and a manifold arrangement extending around the body and connected to the ports for supplying packing material to all of the ports from one location on the manifold arrangement so that packing material can be supplied readily to all of the ports even if some locations aroun
    Type: Grant
    Filed: June 14, 1993
    Date of Patent: June 6, 1995
    Assignee: Adsco Manufacturing Company
    Inventor: David A. Schaefer
  • Patent number: 5299841
    Abstract: An expansion joint for coupling two conduits in a manner allowing relative axial movement therebetween and including an external shell or housing receiving the ends of both conduits and receiving an end of at least one of the conduits in a manner allowing relative axial movement of the end of the conduit in the shell, a flexible metal bellows in the shell connected to the shell and to the end of the one conduit for allowing relative axial movement between the ends of the conduits and for providing a fluid seal between the interiors of the conduits and the end of the expansion joint which receives the one conduit, and characterized by a safety flow restrictor operatively associated with the shell and with the one conduit for restricting fluid flow out the end of the expansion joint which receives the one conduit in the event the bellows fails to maintain the afore-mentioned fluid seal.
    Type: Grant
    Filed: February 8, 1993
    Date of Patent: April 5, 1994
    Assignee: Adsco Manufacturing Corp.
    Inventor: David A. Schaefer
  • Patent number: 4526409
    Abstract: An expansion joint of the bellows type for installation between the end portions of two aligned pipes utilizes two stop members within the bellows being movable relative to one another and each being supported by opposite end portions of the joint for limiting the axial extension of the joint. Each stop member includes a tubular sleeve being fixed at one end to a respective end portion of the joint and a ring at the sleeve end opposite its attached end. When the joint extends axially a predetermined amount, the rings engage one another and prevent any further joint extension.
    Type: Grant
    Filed: January 27, 1983
    Date of Patent: July 2, 1985
    Assignee: Adsco Manufacturing Corp.
    Inventor: David A. Schaefer