Belt Winding Shaft Locking for Stable Lift-Up Bed Positioning

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Solution Overview

Problem

Existing bed lifting apparatus in leisure vehicles, such as campers and yachts, require oversized electric motors or bulky manual mechanisms to securely maintain furniture positions, which are inefficient and unsafe, especially when loads are applied.

Innovation Solution

A locking device with a sliding locking member on the winding shaft, integral housing, and a release lever, which prevents rotation of the shaft when engaged, allowing for a compact and reliable mechanism that supports loads without overworking the drive means.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If oversized electric motors are used to maintain furniture positions under load, then position stability is improved, but device complexity and power consumption increase

Engineering Contradiction:
Improveposition stabilityVSAvoidmotor sizing
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system is divided into two functional segments: a drive means for moving the bed and a separate locking device for maintaining position. The locking device includes a locking member that engages with a locking surface on the winding shaft, independently supporting the load when engaged. This segmentation allows the drive means to be sized only for the moving operation, not for continuously supporting the load.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The locking member acts as an intermediary mechanical element between the winding shaft and the frame. When engaged, it transfers the load from the drive means to the locking member and frame structure, allowing the drive means to be much smaller than would be required if it had to continuously support the full load.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If manual locking mechanisms with pin and gear wheel are used, then position maintenance is improved, but device complexity and safety increase

Engineering Contradiction:
Improveposition maintenanceVSAvoidmechanism structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the locking function from the drive means and implements it through a separate, dedicated locking device. This allows the drive means to be simplified while the locking device provides specialized position maintenance capability through a locking member that engages a locking surface, eliminating the need for complex pin-and-gear mechanisms.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using a mechanism that prevents motion through multiple interfering components (pins, gear wheels, notches), the invention uses a locking member that positively engages a locking surface to prevent reverse rotation. This inverted approach achieves position maintenance with fewer components and improved safety.

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If electric motors continuously support bed weight, then position stability under load is improved, but power consumption increases

Engineering Contradiction:
Improveposition stability under loadVSAvoidmotor power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The locking member is engaged at predetermined positions along the winding shaft to pre-establish load support capability at those positions. When the locking member engages the locking surface, it immediately takes over load support, allowing the drive means to be disengaged or operate at minimal power consumption while maintaining position stability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The locking device is designed to automatically engage and support the load when the bed reaches a desired position, without requiring continuous power input from the drive means. The locking member's engagement with the locking surface creates a self-sustaining position maintenance system that does not consume additional power once engaged.

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 locking device ensures secure and efficient operation of the bed lifting apparatus, preventing accidental rotation and reducing the need for oversized drive components, maintaining position stability with minimal power consumption.

Implementation Method 1

a locking member (41) slidably disposed on said winding shaft (20) for sliding in an axial direction

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

elastic means biasing said locking member towards said wind locking position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2380771B1Locking device in a lifting apparatus with belts, in particular for beds of leisure vehicles
Publication Date: 2012.09.19 ST LA
  • EP2380771B1 patent drawingFigure 1
  • EP2380771B1 patent drawingFigure 2~5
  • EP2380771B1 patent drawingFigure 3~4

AI summary

In a lifting apparatus with belts, in particular for lifting beds or other furniture in leisure vehicles, the belts are wound, thanks to manual or motorized drive means, about a winding shaft (20) pivotably supported by the frame of the lifting apparatus. A locking device (40) comprises a locking member (41) slidably mounted on the winding shaft (20), a locking member housing means (42) integral to the frame (10) and release means (43) for moving the locking member (41) between a position in which the winding shaft (20) is free to rotate and a position in which the locking member (41) engages the locking member housing means (42) so blocking the rotation of the winding shaft (20). The locking device of the invention prevents the rotation of the winding shaft (20) in a simple and reliable way so that the drive means do not have to perform such locking function.