Eyelash Applicator Brush Core Curvature Design
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Solution Overview
Problem
Existing eyelash and eyebrow applicators fail to provide a non-constant and regular wiping action, leading to uneven makeup distribution, especially in the corners of the eye, and do not allow easy access to these areas.
Innovation Solution
The applicator features a brush with a core that has a first and second concave curvature along its longitudinal axis, allowing for non-constant wiping and easy access to the eyelashes in the corners of the eye, with the core being curved around different radii of curvature and having vertices on either side of the longitudinal axis of the rod, ensuring a more even makeup application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the brush core is curved to match the eyelash fringe shape, then access to eyelash corners is improved, but makeup distribution uniformity deteriorates
Solution Approach 1:
The brush core is designed with different curvature radii at different locations: a first curvature radius in the initial section and a second curvature radius in the subsequent section. This local variation in geometric parameters allows the brush to adapt to different anatomical regions of the eyelash fringe, providing both corner access and uniform makeup distribution in different zones
Solution Approach 2:
The brush core employs a progressive curvature design where the curvature radius changes along the length of the core. This dynamic geometric transition enables the brush to smoothly adapt from one curvature regime to another, maintaining consistent product application while navigating the complex geometry of the eyelash fringe including corner areas
2Ease of manufacture
If the brush core has constant curvature, then manufacturing is simplified, but product distribution along the brush becomes non-uniform
Solution Approach 1:
Rather than using a single constant curvature throughout, the brush core implements different curvature radii at different locations. This local differentiation ensures that each section of the brush core is optimized for its specific function while remaining manufacturable through conventional forming processes
Solution Approach 2:
The curvature radius parameter is deliberately changed along the length of the brush core, transitioning from a first curvature radius to a second curvature radius. This parameter variation is designed to achieve uniform product distribution while maintaining ease of manufacture through controlled geometric progression
3Area of stationary object
If the brush is rotated to access corner areas, then coverage is improved, but application time increases
Solution Approach 1:
The progressive curvature design of the brush core allows it to naturally follow the contour of the eyelash fringe including corner areas during a single sweeping motion. This dynamic geometric adaptation eliminates the need for multiple rotation steps, reducing application time while maintaining comprehensive coverage
Solution Approach 2:
The brush core extends into the angular dimension by incorporating specific curvature profiles that enable it to reach corner areas directly along the natural sweep of application. This three-dimensional geometric design allows corner coverage to be achieved in the same dimensional plane as the main eyelash fringe, eliminating the need for additional rotational movements
Data Source
Figure 1~5
Figure 6~49
Figure 7~21b
AI summary
The present invention relates to an applicator for applying a cosmetic product to eyelashes or eyebrows, comprising: - a shaft (4) having a distal portion (4a) extending along a longitudinal axis (X), and - a brush (5) fixed to the distal portion (4a) of the shaft, comprising a core bearing bristles, the core extending along a longitudinal axis (Y) entirely contained in a plane and having a first concave curvature towards a first side and having a second concave curvature towards a second side opposite to the first side, the first curvature being different from the second curvature, the longitudinal axis (Y) of the core passing at least once through the longitudinal axis (X) of the shaft, the core of the brush being devoid of a return towards the distal portion of the shaft, when moving along the longitudinal axis (Y) of the core towards its free end, and the first and second curvatures each comprising a vertex (S1, S2),the two peaks being located on either side of the longitudinal axis of the stem.