×

Drainage material and drainage core for a drainage system

  • US 4,815,892 A
  • Filed: 01/21/1988
  • Issued: 03/28/1989
  • Est. Priority Date: 01/21/1987
  • Status: Expired due to Term
First Claim
Patent Images

1. A drainage system comprising:

  • a mesh structure defining a first face and a second face, having an overall, face-to-face thickness of at least 2.5 mm, and being capable of resisting a pressure over its faces of at least 100 kPa without catastrophic collapse, the mesh structure comprising generally parallel main strands interconnected by generally parallel subsidiary strands, the outer faces of the subsidiary strands being generally coplanar with one of said faces of the mesh structure and the main strands being spaced from said one face, thereby defining main flow channels between and parallel to the main strands and subsidiary flow channels between and parallel to the subsidiary strands, the ratio of the free cross-sectional area of substantially each main flow channel to the free cross-sectional area of substantially each subsidiary flow channel being at least 2.5;

    1, the main strands being at least twice as tall as the subsidiary strands;

    a pervious member against the first face of the mesh structure; and

    a pervious or impervious member against the second face of the mesh structure.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×