Personal Care Appliance Inclined Cylinder Lever Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing personal care appliances face alignment issues and increased friction when using a lever linkage due to stack tolerances and motor eccentric designs, particularly when the motor is distal to the driving bridge, making assembly difficult and inefficient.

Innovation Solution

A personal care appliance design featuring a lever with a cylinder inclined relative to the driving bridge slot, a ratio of cylinder diameter to driving surface height greater than one, and a guide mechanism to facilitate alignment and reduce friction, allowing compatibility with both eccentric and lever mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a thin driving bridge is used with a lever, then friction is reduced, but alignment becomes difficult due to stack tolerances

Engineering Contradiction:
ImprovefrictionVSAvoidalignment
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent introduces an intermediary component (the lever with cylindrical tip) that mediates between the motor and the driving bridge. The cylindrical tip of the lever serves as an intermediary element that engages with the slot in the driving bridge, allowing for both reduced friction through the inclined geometry and reliable alignment through the mechanical engagement of the cylinder with the slot.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the geometric parameters of the driving bridge slot and lever cylinder to resolve the contradiction. By specifying that the cylinder diameter D divided by the driving surface height H is greater than one (D/H > 1), and by inclining the cylinder at angles between 10-30 degrees, the design achieves both reduced friction and reliable alignment. These parameter changes transform the thin driving bridge design into one that works effectively with levers while maintaining low friction.

Inventive Principle:
Principle #35Parameter changes

2Length of moving object

If the motor is moved further away from the driving bridge, then the eccentric becomes unsuitable due to loads, but a lever is then required which conflicts with the thin driving bridge design

Engineering Contradiction:
Improvemotor positionVSAvoidlinkage compatibility
Core Design Contradiction:
Length of moving objectVSAdaptability or versatility

Solution Approach 1:

The patent creates a universal driving bridge design that can accommodate both eccentric and lever linkages. The slot geometry and inclined cylinder configuration allow the same driving bridge to work with different motor positions and linkage types. This multi-functionality resolves the contradiction by making the driving bridge adaptable to various motor locations without requiring separate designs for eccentric and lever configurations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If the cylinder diameter is increased relative to driving surface height, then alignment is improved, but the ratio D/H must be greater than one

Engineering Contradiction:
ImprovealignmentVSAvoidcylinder dimensions
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent establishes a specific parameter relationship (D/H > 1) that resolves the alignment issue without requiring excessive complexity. By defining this clear dimensional relationship and specifying the inclination angle range (10-30 degrees), the design achieves reliable alignment while keeping the cylinder dimensions practical and manufacturable. The parameter change provides a straightforward design rule rather than complex dimensional requirements.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4514574B1Personal care appliance
Publication Date: 2025.07.23 KONINKLIJKE PHILIPS NV
  • EP4514574B1 patent drawingFigure 1
  • EP4514574B1 patent drawingFigure 2
  • EP4514574B1 patent drawingFigure 3

AI summary

The subject-matter of the present disclosure relates to a personal care appliance. The personal care appliance comprises: a handle; a functional device at a head of the handle; a driving bridge for driving the functional device, the driving bridge comprising a slot; a motor within the handle; and a lever coupled between the motor and the driving bridge for reciprocally driving the driving bridge back and forth, the lever comprising a cylinder at a tip inserted in the slot of the driving bridge, wherein the cylinder is inclined with respect to the driving bridge.