For constant tension in web spooling applications.

  • Self regulating. Constant tension from full to empty supply spool
  • Purely mechanical tension control, requires no electrical input
  • Long life under continuous slip conditions
  • Low drag torque during acceleration
  • High brake torque during deceleration
  • Smooth operation, free from jitter
  • Tension unaffected by slip speed
  • Minimizes material spillage
  • Torque ranges from 1 to 50 in·lb
  • Can be supplied as a complete system
Federal supply code - 15531
Unit of Measure


Upper Limit Torque (lb·in)

N/A 6

Unit Weight

N/A 10 oz

A (in)

N/A 1.75

B (in)

N/A 1.87

C - .0003

N/A .3750

D - .0005

N/A .8750

E (in)

N/A .75

F (in)

N/A .09

G (in)

N/A .09

H (in)

N/A 1.88

J (in)

N/A .125

K (in)

N/A 1.21

L (in)

N/A .74

N (in)

N/A .130

O - .0005

N/A .1873

Additional Information

Components for tension control
Maintaining precise and constant web tension is often critical when moving material from a supply reel to a take up spool. In widely differing applications, such as moving film through a camera, or paper through a diagnostic instrument, tension is applied to the material during the process, and the material itself serves as a link in the transport mechanism. The tension prevents slack, keeps the material flat and often provides a working force necessary for other machine operations.

Machine Components Corporation's VT Series of variable torque brakes provide a fundamental building block for a simple, self-regulating mechanical control loop for any such tension control system. In a typical system, the actual tension force in the web material is mechanically fed back to the control crank of the VT brake through a linkage. In response, the drag torque on the VT brake's output shaft is varied directly and instantaneously in response to any change in web tension. Consequently, the material tension in any such system will be maintained constant throughout the spooling process, regardless of the change in the diameter of the material on the supply reel. The VT Series of variable torque brakes has a number of features that provide distinct advantages over competing tensioning control systems. One major feature is that the VT brakes require no electrical input to operate. They are purely mechanical and self-regulating when property applied. In addition to constant tension during steady state conditions, the closed loop arrangement inherently lowers drag torques al the brakes output shaft during acceleration of the spool, and conversely, the torque remaining in the brake increases during deceleration.

Clamping ring
Mounting of a VT brake with a MCC aluminum clamping ring provides the means for infinite angular adjustment of the brake within its linkage arrangements.