Differential Feed Screws

Thayer Scale’s innovative, proprietary compound flight feed screw features a forward-feed helix and a reverse-feed helix concentrically mounted to the same shaft. This design provides reliable material delivery at low flow rates without the complexity of a twin screw.

Benefits of our differential feed screw design include:

  • A large diameter to prevent “boring” through products, or products bridging over the screw’s perimeter
  • Differential action between flights to produce low flow rates with a high screw RPM
  • Uniform and pulse-free feeder discharge
  • Multiple screws with common diameters to eliminate feed tube changes and resulting dead zones

Single feed screws often trigger an array of manufacturing problems, which our differential compound flight feed screws resolve:

Manufacturing Problem

  • Small capacity feed screws with small diameter (and pitch) prevent uniform and reliable filling of screw flights.
  • Large feed screws with large pitches create significant material discharge pulsation during low feed rates.
  • Small feed screws installed in a feeder designed for large feed trigger material buildup and blockage, and prevent comprehensive feeder cleaning.
  • Small diameter feed screws (single and twin) are fragile and unreliable in heavy industrial process applications.

Thayer Scale Feed Screw Resolution

  • The large pitch of the screw’s outer winding ensures reliable and complete filling of screw flights.
  • The screw’s differential feeding action provides consistent, precise and reliable feeding of material without pulsation.
  • The screw’s differential feeding action provides consistent, precise and reliable feeding of material without pulsation.
  • The solid flight screw offers robust over-wind, ensuring reliable performance and long-term durability in harsh process environments.

Alternative to twin screws. A forward feed helix and a reverse feed helix concentrically mounted to the same shaft.

Thayer Technologies