Helicopter Hooking Device with Rotating Ratchet and Lever Lock
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Solution Overview
Problem
Existing hooking devices for suspending loads by slings during helicopter transport face challenges in preventing accidental unhooking, requiring complex operations that often necessitate the use of two hands and cannot be performed from a distance with a pole.
Innovation Solution
A hooking device with a rotatable pawl that can be locked in place using a lever mechanism, allowing single-handed operation and preventing accidental unhooking, featuring a latch and lever system that ensures the pawl remains locked even during load movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a simple spring-held pawl is used to close the hook, then the attachment operation is easy and quick, but the ring can accidentally lift the pawl and come out of the hook during load movements
Solution Approach 1:
The patent applies preliminary action by providing a lever that must be manually moved to a locked position before the pawl can be opened. This preliminary locking action ensures that the pawl cannot accidentally open during load movements, while still allowing quick attachment when the lever is in the locked position. The lever is spring-loaded to automatically return to the locked position after use, maintaining readiness for the next operation.
Solution Approach 2:
The patent introduces an intermediary lever mechanism that mediates between the operator's action and the pawl's position. The lever acts as a mediator that, when moved to the locked position, prevents the pawl from opening accidentally. This intermediary element adds a layer of security without significantly complicating the attachment process, as the lever can be operated with one hand.
2Reliability
If a pawl locking lever is added to prevent accidental opening, then security against roll out is improved, but two hands are required for attachment operations
Solution Approach 1:
The patent merges the locking function and the attachment function into a single lever mechanism. The lever serves dual purposes: when moved to the locked position, it secures the pawl against accidental opening; when in the unlocked position, it allows the pawl to open for attachment. This merging of functions allows the entire operation to be performed with one hand, eliminating the need for a separate locking step that would require two hands.
Solution Approach 2:
The lever is designed as a multi-functional element that performs both the security locking function and the attachment control function. By making the lever universal, it can operate in different positions to achieve different outcomes: locked position for security, unlocked position for attachment. This multi-functionality eliminates the need for separate components and maintains single-handed operation capability while ensuring security against accidental unhooking.
3Reliability
If a complex hook mechanism is used to close the hook automatically, then accidental unhooking is prevented, but the operation becomes complex and cannot be performed from a distance with a pole
Solution Approach 1:
The patent segments the hook mechanism into distinct functional components: the pawl for closing the hook, the lever for locking the pawl, and the spring for automatic resetting. This segmentation allows each component to perform its specific function simply and effectively. The lever provides the necessary security against roll out, while the segmented design keeps the overall operation simple and compatible with remote operation using a pole, as the lever can be actuated from a distance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device securely attaches and detaches loads without risking accidental unhooking, enabling single-handed operation and remote control, thus enhancing safety and efficiency in helicopter sling operations.
Implementation Method 1
a lock spring which exerts on the latch a restoring force towards the locked position
Implementation Method 2
a lever spring which exerts on the lever a restoring force towards the cocked position
Implementation Method 3
a pawl spring which exerts on the pawl a force towards the closed position
Data Source
Figure 1~2b
Figure 2a~3
Figure 4~5
AI summary
A device (100) for lifting and transport of a load hooked by a sling comprises a hook (10), a throat (11) of which is intended to receive a loop (90) or a ring of a sling, and comprises a ratchet (30) rotating between an open position in which an opening of the throat (11) is clear and a closed position in which the opening of the throat is blocked. The device further comprises: - a lock (40) having a locked position in which the lock prevents the rotation of the ratchet (30) in the closed position of the ratchet, and having an unlocked position in which rotation of the ratchet is possible; - a lever (50) having an armed position in which the lever holds the lock (40) in the unlocked position and a released position in which the lever does not hold the lock which is driven towards the locked position by a spring; and a rotation of the ratchet (30) from the closed position to the open position drives the lever (50) from the armed position to the released position. The device also allows the loop of the sling to engage on the hook without a particular action by pushing the ratchet which is automatically locked during the elastic return thereof.