Fail-safe electric actuator

Patent · Tue Jul 19 04:00:00 EDT 1988

OSTI ID:6928524

Wright, J J

In combination with a control mechanism characterized by the ability to be moved from inoperative to operative position and back, a fail-safe actuator device for automatically returning the control mechanism to inoperative position when interruption of electric power occurs is described which comprises: a fluid-driven vaned torque actuator: electric-motor-driven fluid power means for operating the torque actuator; electrically operated valve means for controlling the power fluid flow between the torque actuator and the fluid power generating means; at least one shaft projecting from the torque actuator; coupling means for operatively connecting the shaft to the control mechanism to be operated by the failsafe actuator device; reversible means for storing energy, the reversible means being operatively connected to the shaft; a limit-switch operating cam mounted on and rotable with the shaft; a limit switch positioned for activation by the limit-switch operating cam; and electric circuitry means for interconnecting the motordriven fluid power generating means, the valve means, and the limit switch.

• Assignee: NOV; EDB-88-171206; NOV-88-026131
• Patent Number(s): US 4757684
• OSTI ID: 6928524
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420800* -- Engineering-- Electronic Circuits & Devices-- (-1989)
ACTUATORS
AUTOMATION
CONTROL EQUIPMENT
COUPLINGS
DESIGN
ELECTRIC MOTORS
ELECTRIC POWER
ELECTRICAL EQUIPMENT
ELECTRONIC CIRCUITS
ELECTRONIC EQUIPMENT
ENERGY STORAGE
EQUIPMENT
FLOW REGULATORS
FLUID FLOW
MOTORS
OPERATION
POWER
POWER SUPPLIES
STORAGE
SWITCHES
VALVES