Patents by Inventor Stephen P. Hulley

Stephen P. Hulley 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).

  • Progressive cavity pump or motors
    Patent number: 5474432
    Abstract: A stator assembly for a progressive pump or motor, comprising a resilient material stator (10) having a helical bore (12) therethrough, the cylindrical outer surface (14) of the stator having a plurality of axially extending circumferentially spaced outward projections (16). A rigid generally tubular member (22) has cooperating recesses (24) and may be formed of a unitary tube or of a plurality of shell elements with a cooperating clamp arrangement (32-36). The side faces (18,20) of the projections are flat and either parallel to one another or are inclined towards one another in the radially outward direction.
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: December 12, 1995
    Assignee: Mono Pumps Limited
    Inventors: Stephen P. Hulley, Roger L. Naylor, Gareth D. Thomas