WAir core gauge
WBall screw
WLinear actuator
WComb drive
WHelical band actuator
WHoist (device)
WHydraulic cylinder
WJackscrew
WLinear actuator
WPlasma actuator
WRack and pinion
WRigid belt actuator
WRigid chain actuator
WRoller screw
WRotary actuator
WScratch drive actuator
WSerpentine geometry plasma actuator
WServo (radio control)
WServomotor
WSolenoid
WStepper motor
WTelescopic cylinder
WValve actuator
WWig wag (washing machines)
WFile:Spiralift Patent.jpg