Self-Closing Hinge Piston Guide Block Wear Resistance

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Solution Overview

Problem

Existing self-closing hinges for glass panels, such as shower doors, face challenges in maintaining a stable and accurate closed position over time due to wear resistance issues and piston guidance problems, leading to residual openings that are insufficient for effective sealing, especially with the introduction of hydromassage ramps with horizontal jets.

Innovation Solution

A self-closing hinge design featuring a metallic piston with a flat surface, guided by spaced guide blocks and a spring mechanism, where the piston is biased towards a flat pin, with a hardened surface for increased durability and a rounded guide block for minimized gap between components, along with adjustable positioning and decompression grooves for enhanced sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a piston with flat end and springs are used to achieve automatic return, then the door can be automatically closed, but the mechanism suffers from wear resistance issues and insufficient guidance precision

Engineering Contradiction:
Improveautomatic closing functionVSAvoidwear resistance and guidance precision
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces the traditional mechanical spring-piston-cam system with a hydraulic or pneumatic damper mechanism. The damper uses fluid pressure and viscosity to provide both the automatic closing force and the damping control, eliminating wear-prone mechanical contacts while maintaining the automatic return function. The piston moves within a cylinder filled with viscous fluid, creating hydraulic resistance that provides precise positioning without mechanical wear.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical parameters of the closing mechanism by introducing a damper with adjustable viscosity or pressure characteristics. By modifying the fluid properties or damper configuration, the system achieves precise control over the closing speed and final positioning accuracy, improving both reliability and guidance precision without sacrificing the automatic closing capability.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the piston and springs are mounted on the glass plate, then the structure is simplified, but the piston guidance becomes insufficient

Engineering Contradiction:
Improvemounting structureVSAvoidpiston guidance accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent replaces mechanical guidance elements with hydraulic guidance provided by the damper cylinder. The piston is guided by the cylindrical bore of the damper, which provides precise alignment through hydraulic pressure distribution rather than mechanical guides. This eliminates the need for complex external guidance structures while mounting the entire assembly on the glass plate.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a cylindrical damper body that provides radial guidance through its circular cross-section. The circular geometry of the damper piston and cylinder ensures uniform distribution of forces and maintains precise alignment during rotation, replacing the need for flat or angular mechanical guidance features.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Ease of operation

If a cam mechanism is used for return, then automatic closing is achieved, but the recall position accuracy deteriorates over time due to wear

Engineering Contradiction:
Improveautomatic return functionVSAvoidrecall position accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the cam mechanism with a hydraulic damper system that uses fluid pressure to determine the rest position. The piston naturally settles at a precise position determined by the balance of spring force and hydraulic pressure, without mechanical contact or wear. This eliminates cam wear and maintains consistent recall position accuracy over time.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces hydraulic fluid as an intermediary between the piston and the cam or stop mechanism. The fluid transmits force and pressure uniformly, allowing the piston to achieve and maintain the correct recall position through pressure equilibrium rather than direct mechanical contact, thereby eliminating wear-related position drift.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If the guide block is positioned close to the first plate, then sealing is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvesealing capabilityVSAvoidgap control between components
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent uses a flexible sealing element or film between the guide block and the first plate. This flexible component compensates for manufacturing tolerances and maintains effective sealing even when the gap varies within normal tolerance ranges. The flexible seal deforms to fill irregularities and maintain contact, reducing the stringency of precision requirements.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent employs adjustable positioning features or shims that allow the guide block position to be fine-tuned after assembly. By enabling post-manufacturing adjustment of the gap, the system can achieve optimal sealing without requiring extremely tight manufacturing tolerances during production.

Inventive Principle:
Principle #35Parameter changes

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 ensures a stable and consistent automatic closing position with improved wear resistance and sealing capabilities, maintaining precision to within 1/10 of a degree and effectively managing water pressure through evacuation holes, thus addressing the issues of accuracy and sealing.

Implementation Method 1

a second plate carrying a piston, a pin with at least a flat being fixed to the said yoke and the said piston being elastically biased towards the said flat pin

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

at least the plane surface of the piston which cooperates with the flat has undergone a hardening treatment

Methodology Applied
Scientific EffectHardening treatment: Heat Treatment

Data Source

PatentEP1916369B1Hinge with automatic return.
Publication Date: 2019.05.22 ADLER
  • EP1916369B1 patent drawingFigure 1
  • EP1916369B1 patent drawingFigure 2~3
  • EP1916369B1 patent drawingFigure 4~6

AI summary

The hinge has a plate (12), which carry arms, forming a yoke and another plate (14) carrying a piston (28). A pin (25) is fixed to the yoke and the piston is hooked towards the pin. The plate (14) has guiding blocks (30, 32) which are distant from each other between which the piston is mounted and guided. The block (30) is situated between the arms and houses the pin. An end of the piston situated inside the block (30) includes a flat surface (64) cooperating with a flat section (25a) of the pin, and a helicoidal spring (68) is mounted between a shoulder of the piston and the block (32).