Draw Bar Brake Arrangement with Force-Increasing Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing draw bar mechanisms for retractable screens often fail to provide sufficient braking force to prevent undesired movement in the retraction direction due to the retraction force applied by the biased roller, especially when attempting to maintain the screen in a partially closed position.

Innovation Solution

A draw bar with a brake arrangement that includes a friction surface and a forcing arrangement with a biasing mechanism and a force-increasing mechanism, where the force-increasing mechanism converts frictional force into additional contact pressure to enhance the engagement between the friction surface and the bearing surface, providing increased braking force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a brake arrangement with only biasing mechanism is used, then the structure is simple, but the braking force is insufficient to resist retraction force from the biased roller

Engineering Contradiction:
Improvebraking forceVSAvoidforcing arrangement complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

A forcing part acts as an intermediary element between the friction surface and the biasing mechanism. This forcing part converts the frictional force generated during braking into additional contact pressure force, thereby amplifying the braking force without requiring a more complex biasing mechanism. The forcing part transmits and transforms forces to achieve enhanced braking performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the parameter of contact pressure between the friction surface and bearing surface by introducing the force-increasing arrangement. The frictional force is converted into additional contact pressure force, effectively changing the normal force parameter to increase braking capability while maintaining structural simplicity.

Inventive Principle:
Principle #35Parameter changes

2Force

If the friction surface engages the bearing surface with higher force, then the braking force increases, but the ease of operation for moving the draw bar decreases

Engineering Contradiction:
Improvebraking forceVSAvoidease of moving draw bar
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The brake arrangement transitions from a static friction-based braking system to a dynamic system where the contact pressure is actively increased through the force-increasing arrangement. The forcing part dynamically converts frictional forces into additional contact pressure, allowing the system to provide high braking force when needed while maintaining ease of operation through controlled engagement.

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 enhanced braking force effectively resists relative movement between the brake arrangement and the bearing surface, allowing the screen to be maintained in a partially closed position without unintended retraction, even under the retraction force from the biased roller.

Implementation Method 1

a brake member which provides a friction surface for contacting the bearing surface

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a biasing arrangement for biasing the friction surface towards the bearing surface

Methodology Applied
Scientific EffectElastic force: Spring

Data Source

PatentEP3765701B1Draw bar and brake arrangement for a draw bar
Publication Date: 2024.10.09 FREEDOM SCREENS CAPITAL PTY LTD
  • EP3765701B1 patent drawingFigure 1
  • EP3765701B1 patent drawingFigure 2
  • EP3765701B1 patent drawingFigure 3~4

AI summary

A brake arrangement, for a retractable screen arrangement in which the a screen roller applies a retraction force to the screen and brake arrangement, includes a brake arrangement, for providing a braking force between the brake arrangement and a track which guides the brake arrangement, to resist retraction. The brake arrangement provides a brake member with a friction surface for contacting the bearing surface; a brake member support for supporting the brake member; and a forcing arrangement for forcing the friction surface against the bearing surface. The forcing arrangement includes a biasing arrangement for biasing the friction surface onto the bearing surface, and a force-increasing arrangement for increasing the force with which the friction surface engages the bearing surface. The force increasing arrangement converts a frictional force between the friction surface and the track into additional contact pressure force of the friction surface onto the guide track.