# US 12,006,989 B1 · Propeller locking mechanism > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,006,989 B1 - Document ID: US12006989B1 - Status: Granted - Kind: B1 - Application number: 18/531,624 - Filed: 2023-12-06 - Granted: 2024-06-11 - Earliest claimed: 2023-12-06 - Assignees: Pipistrel d.o.o. - Applicants: Pipistrel d.o.o. - Inventors: Tadej Kosel - Web page: https://patentgrep.com/patent/US12006989B1 ## CPC - F16D 63/006: {Positive locking brakes} - B64C 11/325: {comprising feathering, braking or stopping systems} - B64C 27/322: {Blade travel limiting devices, e.g. droop stops} - B64C 29/0025: {the propellers being fixed relative to the fuselage} - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - B64C: AEROPLANES; HELICOPTERS ## Abstract A propeller locking mechanism for an aircraft includes a mounting ring having a locking extension with an aperture. A solenoid is configured with a solenoid pin which interacts with a first arm of a lever. The lever includes a pivotable second arm configured with a spring and locking pin. The second arm is able to pivot and insert the locking pin into the aperture of the locking extension on the mounting ring. The spring biases the locking pin in the locked orientation. Upon sufficient motor torque, the spring force is overcome allowing the locking pin to be removed from the aperture and the mounting ring to be unlocked. ## Claims ### Claim 1 A propeller locking mechanism for an aircraft, the propeller locking mechanism comprising: a mounting ring having a locking extension, wherein the mounting ring is configured for mounting to an aircraft motor rotor; a solenoid mount mechanically coupled to an aircraft, wherein the solenoid mount comprises a solenoid and a lever operatively coupled to the solenoid, such that the solenoid is configured to pivot the lever within the solenoid mount; a locking pin pivotally coupled to a first arm of the lever, wherein the locking pin is configured for insertion into an aperture of the locking extension for locking the mounting ring; and the solenoid is configured to pivot the lever in a first direction for removal of the locking pin from the aperture for unlocking the mounting ring. ### Claim 2 (depends on 1) The propeller locking mechanism of claim 1 wherein the aperture includes a horseshoe-shaped opening and a profile which slopes away from the aperture on either side of the aperture. ### Claim 3 (depends on 1) The propeller locking mechanism of claim 1 wherein the locking pin is sized and configured to slide into and out of the horseshoe-shaped opening of the aperture for locking and unlocking the mounting ring. ### Claim 4 (depends on 1) The propeller locking mechanism of claim 1 wherein the solenoid includes a solenoid pin configured to engage with a second arm of the lever opposite the first arm. ### Claim 5 (depends on 1) The propeller locking mechanism of claim 1 comprising a pivot bar pivotally coupled to the first arm of the lever. ### Claim 6 (depends on 1) The propeller locking mechanism of claim 1 comprising a spring attached to the first arm of the lever. ### Claim 7 (depends on 1) The propeller locking mechanism of claim 1 comprising a magnet configured to interact with and hold the solenoid pin in a first position or a second position. ### Claim 8 (depends on 1) The propeller locking mechanism of claim 1 wherein the solenoid mount is mounted onto a propeller motor holder. ### Claim 9 (depends on 1) The propeller locking mechanism of claim 1 wherein the mounting ring is unlocked when a motor rotates the mounting ring in a clockwise direction. ### Claim 10 A method for a propeller locking mechanism for an aircraft, the method comprising: engaging a locking pin in an aperture of a mounting ring for securing the locking pin to the mounting ring, wherein the mounting ring is mounted to a propeller hub and the locking pin is pivotally coupled to an aircraft via a lever; actuating the lever via a solenoid for retrieving the locking pin from the aperture thereby unlocking the mounting ring; biasing the locking pin with a spring such that upon release of the lever via the solenoid, the spring biases the locking pin into the aperture. ### Claim 11 (depends on 10) The method of claim 10 comprising rotating the mounting ring via an aircraft motor, wherein the mounting ring is configured to tension the spring and force the locking pin out of the aperture based on a predetermined torque. ### Claim 12 (depends on 10) The method of claim 10 comprising pivoting the lever including a first arm and a second arm wherein a pivot rod is rotatably attached to the first arm and a solenoid pin is configured to engage with the second arm. ### Claim 13 (depends on 10) The method of claim 10 comprising moving the solenoid pin to engage with the second arm of the lever. ### Claim 14 (depends on 10) The method of claim 10 comprising holding the solenoid pin in a locked or unlocked orientation using one or more magnets. ### Claim 15 (depends on 10) The method of claim 10 comprising unlocking the mounting ring using a motor to rotate the mounting ring in a counterclockwise direction.