Anti-Panic Push Bar Silent Operation via Zamak and Curved Spring

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Solution Overview

Problem

Existing anti-panic closing systems with push bars made of folded sheet metal are noisy and perceived as low-quality due to the material's inherent sound production during operation.

Innovation Solution

The use of molded metallic materials, specifically zamak, for the sliding plate and end pieces, combined with a coil spring and curved spring design, provides a silent and smooth operation by maintaining constant pressure and precise alignment, reducing noise and improving the overall feel of the push bar mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If folded sheet metal is used for frames and tilting means, then manufacturing is easier and cost is lower, but noise increases and product quality perception deteriorates

Engineering Contradiction:
Improveease of manufactureVSAvoidnoise
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The invention uses zamak (a zinc-based alloy) for the plate, wheel, spacer, and end piece components instead of folded sheet metal. This composite material approach provides superior damping characteristics that eliminate the noisy metal-box sound while maintaining ease of manufacture through die-casting processes. The zamak material combines the manufacturability benefits of metal forming with the noise-reduction properties of materials having higher internal damping.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If folded sheet metal is used for frames and tilting means, then manufacturing is easier and cost is lower, but product quality perception deteriorates

Engineering Contradiction:
Improveease of manufactureVSAvoidproduct quality
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The zamak material provides a more corpulent, substantial feel that enhances product quality perception. The die-cast construction creates integrated components with smooth surfaces and precise geometries that convey higher quality compared to folded sheet metal assemblies.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention merges multiple components (plate, wheel, spacer, end piece) into single integrated zamak pieces. This consolidation eliminates the need for multiple fasteners and joints in folded sheet metal constructions, resulting in a more reliable assembly with fewer potential failure points and a more premium appearance.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If folded sheet metal structures are used, then device complexity is reduced, but noise and operational smoothness worsen

Engineering Contradiction:
Improvedevice complexityVSAvoidnoise
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The curved spring acts as an intermediary element that mediates between the plate and mobile frame, providing constant elastic pressure to maintain silent, smooth operation. This spring intermediary compensates for any dimensional variations and ensures continuous contact between sliding surfaces, eliminating noise without adding complex adjustment mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of manufacture

If folded sheet metal is used, then manufacturing cost is lower, but operational precision and alignment worsen

Engineering Contradiction:
Improvemanufacturing costVSAvoidalignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The curved spring provides self-adjusting constant pressure that automatically maintains precise alignment between sliding surfaces during operation. The elastic force compensates for wear and dimensional variations, ensuring the plate remains properly aligned with the mobile frame throughout the operational cycle without requiring external adjustment mechanisms.

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 solution results in a silent, smooth, and precise operation of the anti-panic closing system, enhancing user experience and product quality by eliminating the noise associated with folded sheet metal structures while maintaining structural integrity.

Implementation Method 1

elastic means associated with the plate (6) and consisting of a curved spring (10) coupled in the plate (6)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a coil spring (9) installed between the back of the first ramp (16) and a stopper (18) attached to the fixed frame (3)

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP1748129B1Device for an anti-panic closing system intended for emergency doors
Publication Date: 2011.04.20 TALLERES DE ESCORIAZA SA
  • EP1748129B1 patent drawingFigure 1~5
  • EP1748129B1 patent drawingFigure 6~8

AI summary

The system has a push bar (1), and a mobile chassis (4) connected to a fixed chassis (3) across a tilting unit which longitudinally displaces a rod (5). The unit has a plate, an elastic unit associated to the plate, a rocker arm (7), a terminal part (8) connected to the rod and a helical extending spring (9). The spring (9) acts on the part (8) and the chassis (3) during the activation of an opening. The unit is mounted between the plate and the chassis (4) and has a curved spring coupled to the plate, where the curved spring is extended so that its convexity projects above the plate.