Lifting Hook Safety Latch Lever Mechanism

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Solution Overview

Problem

Existing lifting hooks require significant manual effort and risk to keep the safety latch open during load release, limiting user safety and efficiency, as they often necessitate using one hand to maintain the latch open, and there's a risk of injury from the latch mechanism.

Innovation Solution

A locking and releasing lever is integrated into the safety latch, allowing it to be kept open by resting on the hook tip, enabling easy operation with both hands and automatic return to the closed position if damaged, thus enhancing safety and ease of use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the safety latch is kept open manually during load release, then the load can be released, but the user must use one hand to maintain the latch open, preventing use of both hands and creating safety risks

Engineering Contradiction:
Improveease of load releaseVSAvoiduser safety
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The safety latch system performs the function of keeping the latch open automatically without requiring continuous manual intervention. The lever mechanism maintains the latch in the open position by itself once activated, allowing the user to release the load with both hands while the system serves itself to hold the latch open.

Inventive Principle:
Principle #25Self-service

2Reliability

If a powerful spring is used in the safety latch to ensure reliable closing, then the latch returns to closed position reliably, but the user may still hurt hands if they get caught between the latch and hook body

Engineering Contradiction:
Improvelatch closing reliabilityVSAvoidrisk of hand injury
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The lever acts as an intermediary element between the user's hand and the safety latch mechanism. By operating the lever instead of directly manipulating the latch, the user's hand is kept away from the dangerous closing path between the latch and hook body, while the lever transmits the force to open the latch safely.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the safety latch is left open after load fastening, then handling is easier, but the safety latch becomes useless and the hook may rotate during handling

Engineering Contradiction:
Improvehandling convenienceVSAvoidhook stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The safety latch system transitions from a static fixed position to a dynamic controllable state. The lever mechanism allows the latch to be easily moved between open and closed positions as needed during different phases of operation, providing adaptability rather than a fixed state, thus maintaining safety functionality while enabling convenient handling when required.

Inventive Principle:
Principle #15Dynamics

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 solution provides a safer and more efficient operation of the safety latch, reducing the risk of injury and the need for additional personnel, while maintaining low manufacturing costs and clear operation visibility.

Implementation Method 1

a spring arranged between the safety latch and the hook body and forcing the latch end into the closed position

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

a locking and releasing lever that is arranged to turn freely between a turning axle of the safety latch and latch end in the front area of the safety latch and that in its locking position rests against the hook tip and keeps the safety latch in its open position

Methodology Applied
Scientific EffectMechanical support: Mechanical Force

Data Source

PatentEP2943429B1Lifting hook, safety latch of lifting hook and locking and releasing device of safety latch
Publication Date: 2017.11.22 KONECRANES GLOBAL OY
  • EP2943429B1 patent drawingFigure 1~2
  • EP2943429B1 patent drawingFigure 3~4
  • EP2943429B1 patent drawingFigure 5

AI summary

The invention relates to a lifting hook, its safety latch and a locking and releasing device of the safety latch. The lifting hook (1) comprises a hook body (2) having a hook stem (4)and tip (5).The safety latch (6) has a fastening end (7) and a free latch end (8), the fastening end of the safety latch being pivotally fastened close to the stem so as to move the safety latch between an open position and a closed position, the safety latch being in its open position substantially against the inside of the hook body in a position that leaves a hook jaw (G) free,while in the closed position the latch end extends across the hook jaw to the hook tip, closing the jaw on the inside thereof.A spring arranged be- tween the safety latch and hook body forces the latch end into the closed position. The locking and releasing device comprises a locking and releasing lever (10) that is arranged to turn freely between a turning axle of the safety latch (6) and latch end (8) in the front area of the safety latch and that in its locking position rests against the hook tip (5) and keeps the safety latch in its open position against the inner side of the hook body (2).