Patents Assigned to Townsend Controls Pty. Ltd.
  • Patent number: 5076498
    Abstract: A drip irrigation tape and a method and apparatus for manufacture of same in which there are foils of thermoplastics material formed and sealed to produce a main waterway extending along the tape, and a series of tortuous flow restricting channels which are formed in a further foil by forming these in a channel shape mould on a drum, each channel communicating at one position with the waterway and having an outlet at another position to give a drip feed from each channel, the invention further including using an extrusion of thermoplastics foil directly from an extruding machine into such a forming machine, effecting an aperture from the tortuous channel to the main waterway by using a heated finger, effecting an outlet from the tortuous channel by providing an offset channel part which can then be nicked with a hot blade, and effecting an improved sealing together by using spaced apart dimples in providing joining fusing pressure.
    Type: Grant
    Filed: June 9, 1989
    Date of Patent: December 31, 1991
    Assignee: Townsend Controls Pty. Ltd.
    Inventor: James D. Townsend