Spring-Biased Hook Safety Latch Assembly

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing hook assemblies used in material handling applications, such as those with cranes and hoists, often have latches that are prone to damage, necessitating an improved design for both manufacturing efficiency and user safety.

Innovation Solution

A hook assembly with a latch mechanism featuring a biasing member, such as a coil spring, that pivots to secure the latch in a closed position, utilizing a fastener that slides along an elongate slot and engages with a nut to prevent movement, ensuring the latch remains closed even under load, thereby enhancing durability and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a latch mechanism is added to the hook assembly to meet safety requirements, then safety and reliability are improved, but device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The latch body integrates multiple functions into a single component: it provides the latch arm for securing loads, incorporates an elongate slot for fastener movement, includes opposed members with shoulders for positioning, and integrates the pivot connection to the hook. This merging reduces the number of separate parts while maintaining safety functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The latch mechanism serves multiple purposes: it secures the load in the hook, provides a means for assembly through the fastener and slot mechanism, ensures proper positioning through shoulders and opposed members, and maintains closed position through spring biasing. This multi-functionality justifies the added complexity by delivering comprehensive safety and operational benefits.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If a fastener sliding mechanism with elongate slot is used to allow latch rotation, then ease of operation is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveease of operationVSAvoidmanufacturing precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The elongate slot is positioned and dimensioned specifically to allow the fastener to slide only to the extent needed for latch rotation past the tip, then stop at the predetermined position. The slot's geometry (length, width, orientation) is locally optimized to provide just enough movement freedom while maintaining manufacturing feasibility and precision requirements.

Inventive Principle:
Principle #3Local quality

3Reliability

If a biasing member is added to maintain latch in closed position, then reliability is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The biasing member (spring) automatically maintains the latch in the closed position without requiring external actuators or complex control systems. The spring provides continuous force to keep the latch engaged with the tip, and the system self-regulates through the mechanical interaction between the spring, latch, and hook structure.

Inventive Principle:
Principle #25Self-service

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 design enhances the durability and safety of hook assemblies by preventing latch damage and ensuring secure attachment of loads, meeting regulatory requirements while simplifying assembly and maintenance.

Implementation Method 1

A biasing member (49) is configured to bias the latch (40) in a closed position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The fastener (37) is configured to be inserted into the assembly in a first position while the tension on the biasing member (49) is released

Methodology Applied
Scientific EffectMechanical Fastening: Mechanical Fastener

Data Source

PatentEP3939928B1Safety latch for a hook
Publication Date: 2023.10.18 COLUMBUS MCKINNON CORP
  • EP3939928B1 patent drawingFigure 1
  • EP3939928B1 patent drawingFigure 2
  • EP3939928B1 patent drawingFigure 3

AI summary

A hook assembly (10) including a spring-biased safety latch (40) that provides for installation of the latch onto the hook without spring tension.