Dual-Function Angle Roller for Salient and Re-Entrant Corners

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Solution Overview

Problem

Existing corner rollers for drywall finishing require separate tools for salient and re-entrant angles, are cumbersome to switch between positions, prone to coating seepage, and have complex, fragile designs.

Innovation Solution

A multi-purpose corner roller with rollers mounted on both outer and inner surfaces of an angle iron, featuring a handle attachment on the inner surfaces and a pivoting mechanism through a window, allowing easy switching between positions without protrusion and robust construction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a smoothing knife bent at a right angle is used to apply pressing force on both sides of the strip, then the strip adheres evenly to the plaster, but a relatively high application force is required and good experience is needed to avoid tearing the strip

Engineering Contradiction:
Improvestrip adhesion evennessVSAvoidapplication force
Core Design Contradiction:
Manufacturing precisionVSForce

Solution Approach 1:

The pressing function is segmented into multiple rollers (typically three rollers) that contact the strip at different points. Each roller applies distributed pressure independently, replacing the concentrated force of a bent knife with distributed forces that achieve the same adhesion effect with lower overall force requirement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Rollers serve as intermediary elements between the user's applying force and the strip. The rollers transmit and distribute the pressing force evenly across the strip width through rolling contact, eliminating the need for high concentrated force while maintaining even adhesion.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If separate corner rollers are used for salient and re-entrant corners, then each roller is optimized for its specific corner type, but it is necessary to have one of each type and switching between positions is time-consuming

Engineering Contradiction:
Improvecorner-specific optimizationVSAvoidswitching time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

A single corner roller device is designed with multiple rollers arranged to handle both salient and re-entrant corners. By configuring rollers to contact the strip on both inner and outer surfaces of the angle iron, one tool performs the function previously requiring two separate tools, eliminating switching time while maintaining corner-specific effectiveness.

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

Solution Approach 2:

The roller positions and orientations are dynamically configured to adapt to different corner types. The ability of rollers to be positioned on both inner and outer surfaces allows the device to transition between handling salient and re-entrant corners without requiring physical switching of tools.

Inventive Principle:
Principle #15Dynamics

3Strength

If rollers are mounted on an angle iron with tabs extending from outer surfaces, then the handle fixing member can be securely attached, but the assembly becomes more complex and expensive

Engineering Contradiction:
Improvehandle attachment strengthVSAvoidassembly complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

Instead of extending tabs from the outer surfaces of the angle iron, the tabs are positioned on the inner surfaces. This inversion allows the handle fixing member to be attached more simply while maintaining secure attachment strength, as the inner surface positioning provides direct access and reduces structural complexity.

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

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 efficient, quick, and easy tightening of strips on both types of angles with reduced maintenance needs and lower costs due to a robust, simple design.

Implementation Method 1

the rollers delimiting a concave rolling surface... the rollers delimiting a convex rolling surface... applying a pressing force to the strips of paper so that they adhere to the plaster

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4163460B1Dual-function angle roller
Publication Date: 2025.09.17 EDMA
  • EP4163460B1 patent drawingFigure 1~2
  • EP4163460B1 patent drawingFigure 3~4
  • EP4163460B1 patent drawingFigure 5~6

AI summary

The invention relates to a unique, versatile corner roller for clamping bands on both types of angles, robust, inexpensive, quick, and easy to implement. According to the invention, the corner roller comprises an angle bracket (101), two pairs of rollers (110-111) rotatably mounted on the outer surface (102a-103a) of the angle bracket (101) and defining a concave rolling surface (112), two pairs of rollers (120-121) rotatably mounted on the inner surface (102b-103b) of the angle bracket (101) and defining a convex rolling surface (122). The angle bracket (101) further has, pivotally fixed between the inner surfaces (102b-103b), a fastening element (130-230) for a handle (140-240), and a window (104) opposite the fixing element (130-230) for the passage of the handle (140-240) when the latter is fixed to the fixing element (130-230) in the rolling position of the re-entrant angle.