Patents Assigned to Mid-State Drainage Products, Inc.
  • Corrugated pipe
    Patent number: 4852616
    Abstract: A spirally wound corrugated pipe of sheet steel or the like is provided with outwardly convex corrugations which are spaced apart, with a flat portion of single wall thickness between adjacent corrugations. In one embodiment, the corrugation have a pitch of five inches and a height of one-half inch; in another embodiment, the pitch is six inches and the height is one inch.
    Type: Grant
    Filed: March 23, 1987
    Date of Patent: August 1, 1989
    Assignee: Mid-State Drainage Products, Inc.
    Inventor: Richard A. Holcomb