Patent ID: 11873092
Assignee: THE BOEING COMPANY
Field: Transport (Mechanical engineering)
Classification: CPC B  F | IPC B  F

Claim 9:
10. The trim actuator according to claim 9, wherein:
the anti-back-drive mechanism further comprises:
a second ratchet gear, concentrically mounted on the power screw so that the power screw is rotatable relative to the second ratchet gear, wherein the second ratchet gear comprises a second-ratchet-gear first surface, facing the flange second surface, and a second-ratchet-gear second surface, opposite the second-ratchet-gear first surface and facing the housing;
a second ratchet pawl that prevents the second ratchet gear from rotating in the second rotational direction when the second ratchet pawl engages the second ratchet gear;
a second friction device, located between the flange second surface and the second-ratchet-gear first surface; and
a second thrust bearing, located between the second-ratchet-gear second surface and the housing;

the second friction device is configured to form a frictional coupling between the flange and the second ratchet gear when the second force is applied to the nut in the second axial direction along the power screw, wherein the frictional coupling between the flange and the second ratchet gear opposes relative rotational motion between the flange and the second ratchet gear; and
the internal loading of the anti-back-drive mechanism, measured by the sensor when the second force is applied to the nut in the second axial direction along the power screw, is a second load applied to the second ratchet pawl by the second ratchet gear.