Patent attributes
Valve systems include a valve and a valve actuator assembly for operating the valve. The valve actuator assembly includes a drive device and a hand wheel assembly that can independently be used to cause movement of the valve. An anti-back drive component is coupled to the output of the drive device, the hand wheel assembly, or both. The anti-back drive component includes a locking device and an unlocking device, each with respective protrusions that cooperate to define cavities that house pairs of springs and rollers. The shape and orientation of the cavities allows for rotation of the rollers in the cavities and the anti-back drive component by rotating the unlocking device, while preventing rotation of the rollers and the anti-back drive component via rotation of the locking device to selectively prevent rotation of the output of the drive device, hand wheel assembly, or both.
