Touchpad Module Zero-Gap Switch Positioning via Magnetic Stopper

Solution Overview

Problem

Undesired free gaps between touchpad switches and stoppers in information handling systems cause rattling issues due to dimension tolerance deviations, parts deformation, and stress from the manufacturing process.

Innovation Solution

A touchpad module design featuring a stopper positioned within a through hole of a frame, with a magnetic or spring member maintaining contact with the switch to achieve a zero-gap, and an epoxy layer or wedge block mechanism to secure the stopper's position, ensuring consistent engagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional mounting methods are used with dimension tolerances, then manufacturing is easier, but free gaps cause rattling issues and reduced reliability

Engineering Contradiction:

Improvetouchpad stabilityVSAvoidzero-gap positioning

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent replaces traditional mechanical fastening methods (screws, clips, adhesive) with a magnetic field-based positioning system. The magnetic member generates a magnetic field that exerts attractive force on the switch, maintaining precise positioning and eliminating free gaps without requiring mechanical connection elements, thus achieving zero-gap positioning while simplifying the assembly process

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state or properties of the components by introducing magnetic properties to either the switch or the mounting structure. By utilizing magnetic attraction force, the system achieves precise positioning and eliminates dimensional tolerance issues that plague traditional mechanical assemblies, maintaining consistent contact without requiring high manufacturing precision

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If dimensional tolerances are relaxed for easier manufacturing, then production cost decreases, but parts deformation and stress cause free gaps and rattling

Engineering Contradiction:

Improveassembly simplicityVSAvoidrattling noise

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent replaces traditional mechanical fastening methods (screws, clips, adhesive) with a magnetic field-based positioning system. The magnetic member generates a magnetic field that exerts attractive force on the switch, maintaining precise positioning and eliminating free gaps without requiring mechanical connection elements, thus achieving zero-gap positioning while simplifying the assembly process

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies magnetic attraction force in advance to counteract the effects of dimensional tolerances, parts deformation, and thermal expansion before they can cause free gaps or rattling. The magnetic force continuously maintains contact between components, preventing the development of harmful gaps during manufacturing and operation

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If tight tolerances are enforced to eliminate gaps, then touchpad reliability improves, but manufacturing complexity and cost increase

Engineering Contradiction:

Improveswitch contact consistencyVSAvoidpositioning mechanism

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical fastening methods (screws, clips, adhesive) with a magnetic field-based positioning system. The magnetic member generates a magnetic field that exerts attractive force on the switch, maintaining precise positioning and eliminating free gaps without requiring mechanical connection elements, thus achieving zero-gap positioning while simplifying the assembly process

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The magnetic member serves multiple functions simultaneously: it provides positioning, maintains contact pressure, compensates for dimensional variations, and eliminates the need for separate mechanical fastening components. This multi-functionality reduces overall device complexity while achieving reliable switch contact

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 effectively eliminates rattling issues by maintaining a consistent zero-gap between the stopper and switch, enhancing the tactile functionality and reliability of the touchpad module.

Implementation Method 1

The stopper is comprised of a magnetic material, the touchpad module further comprising a magnetic member, wherein the magnetic member maintains a position of the stopper within the through hole to be in contact with the switch

Methodology Applied

Scientific EffectMagnetic attraction: Magnetism

Implementation Method 2

A spring member, the spring member applying a force to a second end of the stopper, the second end of the stopper opposite to the first end of the stopper, wherein the spring maintains a position of the stopper within the through hole to be in contact with the switch

Methodology Applied

Scientific EffectElastic force: Spring

Data Source

PatentUS11573645B1Touchpad module of an information handling system

Publication Date: 2023.02.07 DELL PROD LP

AI summary

A touchpad module including: a touchpad printed circuit board (PCB); a switch coupled to a first side of the touchpad PCB; a touchpad bracket, with at least a portion of the bracket spaced apart from the switch a first distance; a frame, with at least a segment of the frame positioned between the portion of the bracket and the switch, the segment of the frame including a through hole in superimposition with at least a portion of the switch; and a stopper positioned within the through hole and with a first end of the stopper in contact with the switch.