Beard Trimmer Comb Geometry for Uniform Stubble
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Solution Overview
Problem
Existing electric shaving apparatuses are not suitable for maintaining hair at a stubble length, as they require multiple orientations and can cause skin irritations, especially for users with conditions like pseudofolliculitis barbae, and struggle with cutting longer hairs effectively.
Innovation Solution
A beard trimmer with a removable head portion featuring a non-foil type outer cutter and inner cutter that oscillate, accompanied by a comb unit with L- or T-shaped teeth and adjustable hair cutting gaps, allowing for even stubble trimming without specific device inclination and minimizing skin contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a perforated shaving foil is used to trim hair at skin surface, then a clean shave is achieved, but hairs exceeding a certain length cannot be effectively cut and feeding such hairs into perforations is difficult
Solution Approach 1:
The head portion is divided into multiple functional units: a first long hair cutter unit with outer and inner cutters for longer hairs, and a second short hair cutter unit with foil and undercutter for shorter hairs. This segmentation allows the device to handle different hair lengths appropriately without forcing all hairs through a single perforated foil structure.
Solution Approach 2:
The device combines multiple cutting mechanisms (long hair cutter with oscillating cutters and short hair cutter with foil) into a single head portion that can be attached to the handle. This multi-functional design enables the device to trim hairs of varying lengths effectively, making it universally applicable for different stubble length requirements.
2Adaptability or versatility
If projected teeth are used with a guard to set trim length, then cutting length is adjustable, but the user must orient the apparatus in many different positions relative to the skin to achieve desired results
Solution Approach 1:
The comb unit features comb teeth with specific geometric characteristics (L- or T-shaped cross-section) that create localized contact points with the skin. The tooth skin contact surface is positioned at an elevated upper level, creating a localized interaction zone that guides the skin and hair without requiring multiple apparatus orientations.
Solution Approach 2:
The comb teeth extend in a direction transverse to the longitudinal axis of the head portion, creating a two-dimensional contact surface with the skin. This dimensional arrangement allows the device to maintain consistent cutting length regardless of the direction of movement across the skin surface, eliminating the need for multiple orientations.
3Ease of operation
If the device is handled like a traditional shaver, then ease of handling is maintained, but multiple orientations are required to properly thread hairs into gaps between projected teeth
Solution Approach 1:
The comb unit automatically guides and combs the skin and hair during the trimming process. The comb teeth with their specific geometry self-align the hair and skin without requiring the user to manually position or orient the device in different directions. The skin wave naturally enters the gap between comb rows as the device moves across the skin.
Solution Approach 2:
The comb teeth are designed to maintain a consistent relationship with the skin surface throughout the movement of the device. The elevated tooth skin contact surface creates a uniform interaction zone that ensures consistent cutting length and hair threading regardless of the direction or speed of device movement, simplifying the operation to a single straightforward motion.
4Manufacturing precision
If comb teeth are positioned close to the cutter to define trimming length, then cutting precision is improved, but skin contact with the cutter increases causing irritation
Solution Approach 1:
The comb teeth serve as an intermediary element between the skin and the cutter. They contact the skin first, guiding and combing the hair, and then transfer the hair to the cutter for cutting. This intermediary function allows precise trimming length definition through the comb tooth geometry while preventing direct skin contact with the cutter, thereby reducing irritation.
Solution Approach 2:
The comb teeth perform a preliminary combing and guiding action on the hair and skin before the cutting action occurs. By pre-positioning the hair and skin in the optimal configuration, the system achieves precise cutting length control without requiring the cutter to directly contact the skin, thus preventing irritation while maintaining precision.
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
Enables comfortable and efficient trimming of hair to uniform stubble lengths, reducing skin irritation and allowing for easy handling, while effectively cutting hairs of varying lengths without the need for multiple orientations.
Implementation Method 1
The motor drives one or both of the first inner cutter and the first outer cutter in order to oscillate relative to the other in a direction along an x axis and cut hair between the first inner cutter and the first outer cutter
Implementation Method 2
Each comb element is provided with a row of comb teeth and comb slots separating the comb teeth from another. Each of the comb teeth having a tooth skin contact surface which is located on an elevated upper level relative to the cutter skin contact surface and a distance between the tooth skin contact surface and the first inner cutting side defines a hair trimming length.
Data Source
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AI summary
A beard trimmer102 which has a handle 104, a motor 106 and a removable head portion 110. The head portion has first long hair cutter unit 130 for trimming the hair length that is provided with a non-foil type outer cutter 140 and an inner cutter 150. A first comb unit 171A is provided having comb elements 178 located adjacent to multiple cutting slots of the outer cutter. One comb element is provided on each of the opposite sides of the outer cutter. Each comb element provided with a row of comb teeth 172 and comb slots 177 separating the comb teeth from another. Each of the comb teeth has a tooth skin contact surface 182 which is located on an elevated upper level relative to a cutter skin contact surface of the outer cutter.