Sliding Lid Tray Assembly Reducing Ejection Force

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Solution Overview

Problem

Existing tray assemblies for electronic devices require high ejection forces and are prone to jamming due to high friction, making them difficult to use, especially in handheld devices.

Innovation Solution

A tray assembly with a slidably connected lid and a resiliently biased locking mechanism, actuated by an electro-mechanical actuator, such as an SMA wire, that minimizes friction by allowing only the lid to move, reducing the size of ejection components and activation energy needed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the complete tray assembly is moved by an electro-mechanical actuator, then the card can be ejected from the device, but the friction forces are high requiring large actuator size and high activation energy

Engineering Contradiction:
Improveejection forceVSAvoidactivation energy
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The tray assembly is divided into two independent parts: a stationary tray that remains in the housing, and a movable lid that can be ejected independently. This segmentation allows the electro-mechanical actuator to move only the lid rather than the entire tray assembly, significantly reducing the mass to be accelerated and the friction forces to be overcome, thereby lowering both ejection force requirements and activation energy consumption

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lid is extracted as a separate movable component from the traditional unified tray structure. By taking out the lid as an independent element that can be ejected separately, the system eliminates the need to move the heavier tray body and card contents during ejection, reducing the overall energy requirement and enabling the use of smaller, more energy-efficient actuators

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If the complete tray assembly is moved, then the card is accessible, but the risk of ejection jamming is high due to high friction

Engineering Contradiction:
Improveejection smoothnessVSAvoidejection jamming risk
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

By segmenting the tray into a stationary body and a movable lid, the patent reduces the contact area and friction points during ejection. Only the lid slides along guide surfaces while the tray remains fixed, minimizing friction-induced jamming compared to moving the entire assembly through the housing recess

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lid acts as an intermediary component between the user's ejection action and the card access function. It provides a smooth sliding interface that reduces direct friction between the tray and housing walls, thereby minimizing jamming risk while still enabling full card accessibility when the lid is ejected

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the complete tray assembly is ejected, then the card is accessible, but the ejection components must be large to overcome high friction

Engineering Contradiction:
Improveejection capabilityVSAvoidactuator size
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The ejection function is segmented into two independent operations: ejection of the lid (automated by electro-mechanical actuator) and access to the card (manual removal of lid). This allows the actuator to be sized for moving only the lightweight lid rather than the entire tray assembly, significantly reducing actuator dimensions while maintaining full ejection capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces the traditional mechanical spring-loaded ejection system with an electro-mechanical actuator. This substitution enables more precise and efficient force application, allowing for a smaller actuator design that can still overcome the reduced friction forces associated with moving only the lid rather than the complete tray assembly

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

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

This design reduces the required ejection force, minimizes the risk of jamming, and enhances user satisfaction by allowing easy access to integrated circuit cards with lower activation energy, particularly beneficial for handheld devices.

Implementation Method 1

the lid being resiliently biased towards the extended position

Methodology Applied
Scientific EffectResilient biasing: Elasticity

Implementation Method 2

an electro-mechanical actuator configured to control the locking mechanism

Methodology Applied
Scientific EffectElectro-mechanical actuation: Electromagnetic Induction

Implementation Method 3

the electro-mechanical actuator comprises an SMA, shape memory alloy, component

Methodology Applied
Scientific EffectShape memory alloy phase transition: Shape Memory Alloy

Data Source

PatentEP3586447B1Tray assembly for electronic device
Publication Date: 2021.05.12 HUAWEI TECH CO LTD
  • EP3586447B1 patent drawingFigure 1~3
  • EP3586447B1 patent drawingFigure 4(a)~4(b)
  • EP3586447B1 patent drawingFigure 5(a)~5(c)

AI summary

A tray assembly (1) comprising a tray (2) and a lid (3). The tray comprises a main plane (4) and is adapted for carrying an integrated circuit card (5). The lid (3) is slidably connected to the tray (2) to allow the lid (3) to move relative to the tray (2) in a direction along an axis (A) of the main plane (4), between a retracted position (P1) and an extended position (P2) relative to the tray. The lid (3) is resiliently biased towards the extended position (P2). The tray assembly (1) further comprises a locking mechanism (6) adapted for retaining the lid (3) in the retracted position (P1), and an electro-mechanical actuator (7) configured to control the locking mechanism (6).