Telescopic Hold Open Rod Locking Assembly for Safe Door Support
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing telescopic hold open rods for aircraft cowling require a lock mechanism to prevent unintentional collapse, but existing solutions are not compact enough or easy to engage/disengage safely.
Innovation Solution
A telescoping rod assembly with a locking apparatus that includes a cylinder end fitting with locking grooves, lock segments, an outer sleeve, and an unlock sleeve, which automatically locks the rod in an extended position and can be unlocked only when fully extended and under user control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lock mechanism is added to prevent unintentional collapse, then reliability is improved, but device complexity increases
Solution Approach 1:
The lock segment is nested within the rod segment, with the lock segment's outer surface fitting into a lock segment cavity in the rod segment. This nesting approach integrates the locking function within the existing rod structure rather than adding separate external components, thereby improving reliability while minimizing the increase in device complexity.
Solution Approach 2:
The lock mechanism is designed to automatically engage and disengage based on the telescopic motion of the rod segments. The lock segment automatically locks when the rod extends and automatically unlocks when the rod compresses, eliminating the need for manual operation or complex control systems, thus improving reliability without significantly increasing device complexity.
2Volume of moving object
If the rod segments are nested for compact stowed volume, then volume is improved, but ease of operation worsens due to automatic locking requirement
Solution Approach 1:
The rod segments are nested within each other in a telescopic arrangement, with the first rod segment nested inside the second rod segment. This nesting provides compact stowed volume while the automatic lock mechanism ensures safe operation during extension and retraction, balancing compactness with ease of operation.
Solution Approach 2:
The lock mechanism automatically engages and disengages based on the telescopic motion, requiring no manual intervention from the user. The lock segment automatically locks when the rod extends to its full length and automatically unlocks when the rod compresses, making the operation as easy as simple telescopic motion while maintaining safety.
3Ease of operation
If the lock mechanism is made easy to disengage, then ease of operation is improved, but reliability worsens due to potential unintentional collapse
Solution Approach 1:
The lock mechanism is designed to automatically disengage only when the rod segments are in the compressed state, where the lock segment cavity aligns with the lock segment. This automatic disengagement based on rod position ensures easy operation while preventing unintentional collapse, as the lock remains engaged during extended positions where collapse would be harmful.
Solution Approach 2:
The lock mechanism prevents unintentional collapse by maintaining engagement during the extended position where collapse would be harmful. The automatic locking action occurs before any potential collapse can occur, and the automatic disengagement only occurs when the rod is compressed and collapse is no longer a risk, thus preventing harmful effects while maintaining ease of operation.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A door and hold open rod assembly of an aircraft includes a door, and a hold open rod assembly secured to the door. The hold open rod assembly is configured to support the door in an opened position when the hold open rod is deployed. The hold open rod assembly includes a first rod segment (30) extending along a rod central axis, a second rod segment (32) surrounding the first rod segment (30) and in a telescoping arrangement with the first rod segment (30), and a locking apparatus (34) operably connected to the first rod segment (30) and the second rod segment (32), the locking apparatus (34) configured to automatically lock the first rod segment (30) in an extended position relative to the second rod segment (32).