Detent Latching Mechanism for Single-Direction Caster Lift

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Solution Overview

Problem

Existing motion transfer mechanisms for articulating beds and similar applications lack efficient mechanisms to lift and latch wheels or casters off a support surface, requiring complex and unreliable systems for engagement and disengagement.

Innovation Solution

A latching motion transfer mechanism that uses a detent member and catch system, where applying force in one direction initially lifts and latches, and reversing the force lowers, utilizing a biasing member and drive mechanism to maintain synchronization between multiple mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex motion transfer mechanism is used to lift and latch casters, then the lifting function can be achieved, but the system becomes unreliable and difficult to operate

Engineering Contradiction:

Improvereliability of lifting and latchingVSAvoidcomplexity of motion transfer mechanism

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The mechanism is divided into distinct functional components: a drive member that receives input force, a detent member that provides latching, and a plunger that transfers motion. Each component has a specific function, simplifying the overall system while maintaining reliability. The detent member segments the motion path into discrete latched and unlatched positions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The biasing member automatically returns the plunger to its initial position after actuation, eliminating the need for a separate return mechanism. The detent member self-latches when the plunger reaches its actuated position, providing automatic engagement without additional control elements.

Inventive Principle:

Principle #25Self-service

2Ease of operation

If force is applied in multiple directions to achieve lifting and lowering, then the mechanism can be actuated, but the operation becomes less efficient and more complex

Engineering Contradiction:

Improveease of actuationVSAvoidefficiency of lifting and lowering

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

Instead of requiring separate actuation mechanisms for lifting and lowering, the system uses a single drive member that can be actuated in one direction to lift and latch, then automatically returns to lower and unlatch. The biasing member provides the return force, inverting the traditional approach where active force is needed for both directions of motion.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The mechanism operates through periodic application of force to the drive member. Each actuation cycle lifts and latches the mechanism, and each release cycle lowers and unlatches it. This periodic single-direction actuation simplifies operation compared to continuous bidirectional control.

Inventive Principle:

Principle #19Periodic action

3Adaptability or versatility

If multiple latching positions are provided, then the mechanism can be secured at different positions, but the device complexity increases

Engineering Contradiction:

Improvenumber of latching positionsVSAvoidcomplexity of detent and catch system

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The detent member features an asymmetric profile with a head portion and a body portion of different geometries. The head portion engages with a first catch for one latching position, while the body portion engages with a second catch for another position. This asymmetric design enables multiple latching positions without requiring symmetric duplicate components.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The single detent member performs multiple functions: it provides both latched and unlatched positions, engages with different catches for different positions, and automatically transitions between states. This multi-functionality achieves adaptability without proportionally increasing device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enables reliable and efficient lifting and lowering of wheels or casters by applying force in a single direction, ensuring consistent engagement and disengagement, and maintaining synchronization between linked mechanisms for coordinated operation.

Implementation Method 1

a biasing member disposed in the channel between the plunger and an end wall of the channel and configured to urge the plunger in a first direction when the drive member is not actuated

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS9381126B2Latching motion transfer mechanism

Publication Date: 2016.07.05 INVACARE CORP

AI summary

Latching motion transfer arrangements may be used to raise an object up and out of the engagement with the ground or other support surface and to lower the object back onto the ground or other support surface. In one exemplary embodiment, the mechanism is caused to lift and latch by applying force in a first direction, a first time, and is caused to release and lower by applying force in the first direction, a second time.