Lock mechanism of telescopic hold open rod

1 . A rod assembly comprising:

a first rod segment extending along a rod central axis;

a second rod segment surrounding the first rod segment and in a telescoping arrangement with the first rod segment; and

a locking apparatus operably connected to the first rod segment and the second rod segment, the locking apparatus configured to automatically lock the first rod segment in an extended position relative to the second rod segment;

wherein the locking apparatus comprises:

a cylinder end fitting of the second rod segment surrounding the first rod segment, the cylinder end fitting including at least one locking groove; and

at least one lock segment installed into a segment opening;

wherein the at least one lock segment is configured to engage with the at least one locking groove when the first rod segment is moved to the locking position relative to the second rod segment when an unlock sleeve disposed radially inboard of the cylinder end fitting is not covering the locking groove.

2 . The rod assembly of claim 1 , wherein the locking apparatus comprises:

an outer sleeve surrounding the cylinder end fitting; and

the unlock sleeve;

wherein the unlock sleeve is configured to block the at least one locking groove to prevent engagement of the at least one lock segment into the at least one locking groove unless the first rod segment is in the extended position and the unlock groove is uncovered due to upward movement of unlock sleeve under spring force.

3 . The rod assembly of claim 2 , wherein the cylinder end fitting includes at least one ball installed thereto, the ball selectably engageable into a detent formed in the outer sleeve when the rod assembly is in the unlocked position.

4 . The rod assembly of claim 3 , wherein the ball is urged into engagement with the detent via a detent sleeve disposed radially inboard of the unlock sleeve.

5 . The rod assembly of claim 2 , wherein the outer sleeve is secured to the unlock sleeve via at least one dowel pin extending through at least one pin slot in the cylinder end fitting.

6 . The rod assembly of claim 1 , wherein the at least one lock segment includes a wear resistant insert installed thereto to prevent wear of the second rod segment.

7 . The rod assembly of claim 1 , wherein the at least one lock groove includes a dovetail shaped engagement surface at which a complimentary engagement tab of the lock segment is engageable.

8 . A door and hold open rod assembly of an aircraft, comprising:

a door; and

a hold open rod assembly secured to the door, the hold open rod assembly configured to support the door in an opened position when the hold open rod is deployed, the hold open rod assembly including:

a first rod segment extending along a rod central axis;

a second rod segment surrounding the first rod segment and in a telescoping arrangement with the first rod segment; and

a locking apparatus operably connected to the first rod segment and the second rod segment, the locking apparatus configured to automatically lock the first rod segment in an extended position relative to the second rod segment;

wherein the locking apparatus comprises:

a cylinder end fitting surrounding the first rod segment, the cylinder end fitting including at least one locking groove;

at least one lock segment installed into the at least one locking groove in the cylinder end fitting, the at least one lock segment biased toward the at least one locking groove;

an outer sleeve surrounding the cylinder end fitting; and

an unlock sleeve disposed radially inboard of the cylinder end fitting;

wherein the at least one lock segment is configured to engage with the at least one locking groove when the first rod segment is moved to the extended position relative to the second rod segment; and

wherein the unlock sleeve is configured to block the at least one locking groove to prevent engagement of the at least one lock segment into the at least one locking groove unless the first rod segment is in the extended position.

9 . The door and hold open rod assembly of claim 8 , wherein the cylinder end fitting includes at least one ball installed thereto, the ball selectably engageable into a detent formed in the outer sleeve when the rod assembly is in the unlocked position.

10 . The door and hold open rod assembly of claim 9 , wherein the ball is urged into engagement with the detent via a detent sleeve disposed radially inboard of the unlock sleeve.

11 . The door and hold open rod assembly of claim 8 , wherein the outer sleeve is secured to the unlock sleeve via at least one dowel pin extending though at least one pin slot in the cylinder end fitting.

12 . The door and hold open rod assembly of claim 8 , wherein the at least one lock segment includes a wear resistant insert installed thereto to prevent wear of the second rod segment.

13 . The door and hold open rod assembly of claim 8 , wherein the at least one lock groove includes a dovetail shaped engagement surface at which a complimentary engagement tab of the lock segment is engageable.

14 . An engine assembly of an aircraft, comprising:

an engine body;

a cowling configured to at least partially enclose the engine body, the cowling movable between a closed position and an opened position; and

a hold open rod assembly secured to the cowling, the hold open rod assembly configured to support the cowling in an opened position when the hold open rod is deployed, the hold open rod assembly including

a first rod segment extending along a rod central axis;

a second rod segment surrounding the first rod segment and in a telescoping arrangement with the first rod segment; and

a locking apparatus operably connected to the first rod segment and the second rod segment, the locking apparatus configured to automatically lock the first rod segment in an extended position relative to the second rod segment;

wherein the locking apparatus comprises:

a cylinder end fitting surrounding the first rod segment, the cylinder end fitting including at least one locking groove;

at least one lock segment installed into the at least one locking groove in the cylinder end fitting, the at least one lock segment biased toward the at least one locking groove;

an outer sleeve surrounding the cylinder end fitting; and

an unlock sleeve disposed radially inboard of the cylinder end fitting;

wherein the at least one lock segment is configured to engage with the at least one locking groove when the first rod segment is moved to the extended position relative to the second rod segment; and

wherein the unlock sleeve is configured to block the at least one locking groove to prevent engagement of the at least one lock segment into the at least one locking groove unless the first rod segment is in the extended position.

15 . The engine assembly of claim 14 , wherein the cylinder end fitting includes at least one ball installed thereto, the ball selectably engageable into a detent formed in the outer sleeve when the rod assembly is in the unlocked position.