Trapezoidal Screw Jacks

  • Produced in many different models
  • Sizes from 5 kN to 1500 kN.
  • Trapezoidal Work Screw thread.
  • Positive mechanical actuation.
  • Precise positioning.
  • Uniform speed
  • Available with the Antibacklash device.
  • Trapezoidal Screw Jacks having high gear ratios and standard design are generally self-locking and will hold loads without backdriving in the absence of vibrations.


Anti-backlash Device

Anti-Backlash Screw Jacks are used wherever reversible load conditions require precision positioning control.
The unit allows the lash between the drive sleeve and the Work Screw thread(1) to be accurately controlled by the relative position of the upper (2) and lower (3) drive sleeves.
Adjustment of the cover (4), by loosing set Screws (5), changes the relative distance between the sleeves. This change in distance compensate for any slash.
Axial backlash should be minimized but not completely eliminated, the result would be a lock-up of the Jack. When top plate touch the Jack body, the Jack wear is at the limit and Jack shall be revised.


Anti-Rotation Device

When Work Screw rotation must be prevented, the Jacks can be realized with keyway along the Work Screw, a matching key (6) is fastened to the cover of the Jack which will eliminate Work Screw rotation.
Anti-rotation device is suggested for limited strokes and low speed.
The Anti-rotation device causes greater than normal wear on the Work Screw, somewhat reducing Jack life.


SCREW JACKS WITH BASE

  • Uniform translation speed.
  • Standard Jacks are generally self locking, for non vibrating applications.
  • Capacity from 5 kN to 1500 kN.
  • Gear ratios from 5:1 to 36:1.
  • Standard model: Body in Nodular Cast Iron, Worm Screw in high resistance Stainless Steel, Worm Gear in special Bronze, Work Screw in high resistance Steel.
  • Stainless Steel model: Body in Cast Stainless Steel, Worm Screw in high resistance Stainless Steel, Worm Gear in special Bronze, Work Screw in Stainless Steel.
  • Mechanical stops for max extension (Do not use as positive stop, but for emergency only).
  • Work Screw threads protection.
  • Screw Jacks complete with greaser nipples and end shaft keys.
  • Anti-Backlash device.
  • Anti-Rotation device.
  • Work Screw protections in Neoprene or protections with spiral spring.
  • Additional guidance of the Work Screw.
  • Special sealing to avoid internal contamination.
  • Standard models, without Anti-Rotation device, requires the end of the Worm Screw to be held in position to prevent rotation.
  • Tables indicates overall dimensions and characteristics for standard models.
  • Loads capacity and dimensions are identical for both standard and Stainless Steel versions.

OSCILLATING SCREW JACKS

  • Double clevis system.
  • Uniform translation speed.
  • Standard Jacks are generally self locking, for non vibrating applications.
  • Capacity from 10 kN to 300 kN.
  • Gear ratios: from 5:1 to 32:1.
  • Standard model: Body in Nodular Cast Iron, Worm Screw in high resistance Stainless Steel, Worm Gear in special Bronze, Work Screw in high resistance Steel.
  • Stainless Steel model: Body in Cast Stainless Steel, Worm Screw in high resistance Stainless Steel, Worm Gear in special Bronze, Work Screw in Stainless Steel.
  • Mechanical stops for max extension (Do not use as positive stop, but for emergency only).
  • Work Screw threads protection.
  • Screw Jacks complete with greaser nipples and end shaft keys.
  • Rotating Screw version (ask for details).
  • Anti-Backlash device.
  • Anti-Rotation device.
  • Work Screw protections in Neoprene or protections with spiral spring.
  • Additional guidance of the Work Screw.
  • Special sealing to avoid internal contamination.
  • Standard models, without anti-rotation device, require the end of the Worm Screw to be held in position to prevent rotation.
  • Tables indicates overall dimensions and characteristics for standard models.
  • Loads capacity and dimensions are identical for both standard and Stainless Steel versions.

ROTATING SCREW JACKS

  • Uniform translation speed of the nut.
  • Standard Jacks are generally self locking, for non vibrating applications.
  • Capacity from 5 kN to 150 kN.
  • Gear ratios: from 5:1 to 36:1.
  • Standard model: Body in Nodular Cast Iron, Worm Screw in high resistance Stainless Steel, Worm Gear in special Bronze, Work Screw in high resistance Steel.
  • Stainless Steel model: Body in Cast Stainless Steel, Worm Screw in high resistance Stainless Steel, Worm Gear in special Bronze, Work Screw in Stainless Steel.
  • Screw Jacks complete with grasser nipples and end shaft keys.
  • Mechanical stops for max/min extension. (Do not use as positive stops, but for emergency only).
  • Special sealing to avoid internal contamination.
  • Tables indicates overall dimensions and characteristics for standard models.
  • Loads capacity and dimensions are identical for both standard and Stainless Steel versions.