Vertically Oriented PCB With Projections for Smoke Detector Assembly

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Solution Overview

Problem

The assembly of traditional smoke detectors is labor-intensive and difficult to automate, particularly due to the complex placement of optical and temperature sensors within the detector housing.

Innovation Solution

A vertically oriented printed circuit board (PCB) with a planar shape and protrusions for temperature sensors, allowing for automated mounting of sensors and a compact smoke detection design with integrated light emitters and receivers, enabling efficient manufacturing and reduced manual labor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If traditional sensor placement methods are used, then sensors can be placed in the detector housing, but the assembly process becomes labor-intensive and difficult to automate

Engineering Contradiction:
Improveassembly automationVSAvoidassembly complexity
Core Design Contradiction:
Extent of automationVSEase of manufacture

Solution Approach 1:

The patent combines multiple sensor mounting functions into a single integrated PCB structure. The PCB includes integrated mounting features for both optical sensors and temperature sensors, eliminating the need for separate mounting operations and enabling automated assembly processes.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from traditional planar PCB mounting to a three-dimensional structure with vertical projections extending from the PCB surface. This dimensional change allows sensors to be positioned in space while maintaining automated assembly compatibility through standardized mounting features.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If optical components are placed in a preform-jig for predetermined angles, then accurate optical alignment is achieved, but the assembly process becomes labor-intensive

Engineering Contradiction:
Improveoptical alignment precisionVSAvoidassembly efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent incorporates pre-formed mounting features and alignment structures directly into the PCB during manufacturing. Optical components are positioned using these pre-integrated features, eliminating the need for separate preform-jig alignment operations and enabling direct automated assembly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical preform-jig alignment system with integrated PCB mounting structures that provide predetermined angular positioning. This substitution eliminates complex mechanical alignment tools while maintaining precise optical component positioning.

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

3Adaptability or versatility

If a vertically oriented PCB is used, then automated mounting and compact design are enabled, but the PCB structure becomes more complex

Engineering Contradiction:
Improvedesign versatilityVSAvoidPCB structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent divides the PCB into functional segments with distinct mounting projections for different sensor types. This segmentation allows each section to be optimized for its specific function while maintaining overall structural integration, making the complexity manageable and modular.

Inventive Principle:
Principle #1Segmentation

4Reliability

If temperature sensors are mounted on PCB projections, then access for air flow and temperature sensing is improved, but the PCB design becomes more complex

Engineering Contradiction:
Improvetemperature sensing accuracyVSAvoidPCB design complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent provides localized three-dimensional projections at specific PCB locations where temperature sensors need enhanced air flow access. These projections are strategically positioned only where needed for sensing accuracy, while the rest of the PCB maintains a simpler structure.

Inventive Principle:
Principle #3Local quality

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 enables efficient and automated assembly of smoke detectors with improved access for air flow and temperature sensing, reducing manufacturing complexity and increasing design versatility while maintaining accurate temperature and smoke detection capabilities.

Implementation Method 1

Detecting smoke fires may be performed using a light emitter and a light receiver disposed at an angle relative to each other. The detector may sense light scattered by smoke.

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

For heat sensing, a leaded thermistor may be soldered to the PCB. The leads may allow a sensing element to be placed in the airstream.

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3803819B1Printed circuit board for smoke detector
Publication Date: 2024.05.01 AUTRONICA FIRE & SECURITY
  • EP3803819B1 patent drawingFigure 1
  • EP3803819B1 patent drawingFigure 2
  • EP3803819B1 patent drawingFigure 3

AI summary

Disclosed is a smoke detector comprising: a housing including a base, the base including a planar surface configured for being positioned against and attached to a ceiling, a printed circuit board (PCB) comprising a substantially planar shape with a front surface and an opposing back surface spaced in a thickness direction T, and a plurality of perimeter edges including a bottom edge and an opposing top edge spaced in a height- wise direction H, a first side edge and an opposing second side edge spaced in a transverse direction, wherein the top edge comprises a first projection extending in the height-wise direction away from the top edge, the first projection including a first temperature sensor height- wise spaced from the top edge, and the PCB is mounted to the housing so that the front surface of the PCB is perpendicular to the planar surface of the base.