6. Increase Skull Clamp force by advancing the Torque Screw to a desired setting, indicated on the
visual readout, then back off one quarter turn.
NOTE: The Torque Screw provides the surgeon with a visual display of the clamping
force applied. Each scribed line indicates a 20 lbs. (89 N) increment of force. Refer
to Table 2 below:
Table 2 Torque Screw Line Indicator/Clamping Force
NOTE: To achieve independent fixation for adults, it is recommended that a
minimum of 60 lbs. (267 N) of force be applied by the Skull Clamp. An additional
force range reaching 80 lbs. (356 N) is available if desired.
7. Once the force is applied to the clamp and the patient is positioned for surgery, the Index
Locking Knob should be turned to the locked position shown in Figure 4.
Never exceed 80 lbs. (356 N) of force.
Over-tightening the Index Locking Knob can result in damage to the skull clamp.
Torque Screw
Line Indicator
=
1
=
2
=
3
=
4
WARNING!
CAUTION!
Figure 7 Standard Torque Screw
Page 9
Clamping
Force
20 lbs. (89 N)
40 lbs. (178 N)
60 lbs. (267 N)
80 lbs. (356 N)