Patent ID: 7475477
Filing Date: 2009-01-13
Classification: B65D,E02B,F16L,Y02W,Y10T

Abstract:
1. A method for making drainage elements comprising the steps of generating a first strip of mesh material having a pair of parallel longitudinal edges; generating a second strip of filter material having a pair of parallel longitudinal edges; securing one of said edges of said first strip to one of said edges of said second strip to form a web; shaping said web about a tube to dispose the other of said edges of said first strip in facing relation to the other of said edges of said second strip securing said other edges in facing relation to each other to define a tubular sleeve about the tube; closing one end of the sleeve at a point spaced from the tube; thereafter feeding a light weight aggregate through the tube and into said sleeve while moving said sleeve in a direction away from the tube; and thereafter closing the sleeve at a predetermined point spaced from said one end of the sleeve and spaced from the tube to define a drainage element.