Sinusoidal Flat Key Profile for Cylinder Lock Anti-Picking
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Solution Overview
Problem
Existing cylinder locks are vulnerable to electro-picking, a method where unauthorized access is gained by vibrating a wire through the keyway to release the lock, and existing solutions like paracentric key profiles reduce key stability and increase manufacturing costs.
Innovation Solution
A cross-sectional profile for flat keys and cylinder locks featuring sinusoidal profiling lines with varying phases and amplitudes, creating a paracentric design that projects beyond the centerline, combined with trapping calottes in the keyway to prevent electro-picking, while maintaining stability and low manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a paracentric key profile is used to prevent electro-picking, then security against misuse is improved, but key stability is reduced and material is wasted
Solution Approach 1:
The patent applies sinusoidal curvature to the lateral surfaces of the key, creating a wave-like profile that projects beyond the centerline. This curved geometry effectively blocks electro-picking wires while maintaining structural integrity through distributed material placement rather than concentrated removal.
Solution Approach 2:
The invention modifies the key profile by introducing sinusoidal variations with specific amplitudes and phases that project beyond the centerline. By carefully controlling these parameters, the design achieves anti-picking protection while optimizing material retention and key stability.
2Object-affected harmful factors
If a paracentric key profile is used to prevent electro-picking, then security against misuse is improved, but manufacturing complexity increases
Solution Approach 1:
The sinusoidal profile is defined by mathematical parameters (amplitude, phase, wavelength) that can be directly programmed into CNC machining centers. This parametric approach simplifies manufacturing by allowing precise control through software rather than requiring complex tooling or multiple processing steps.
Solution Approach 2:
The invention replaces traditional mechanical key cutting methods with computer-controlled sinusoidal profiling. This substitution enables more efficient manufacturing through automated programming and reduces the need for specialized tooling, thereby lowering overall manufacturing costs.
3Loss of substance
If sinusoidal profiling lines are used with centerlines within the base profile, then material usage is reduced, but key stability may be compromised
Solution Approach 1:
The patent optimizes the sinusoidal profile parameters so that the centerlines remain within the base profile boundaries. This careful parameter selection achieves material efficiency by removing only the minimum necessary material while preserving sufficient material for structural stability.
Solution Approach 2:
The sinusoidal profiling is applied selectively to specific regions of the key lateral surfaces, concentrating material removal where it provides maximum anti-picking effectiveness while preserving material in critical structural areas. This localized approach balances material reduction with stability requirements.
Data Source
AI summary
The invention relates to a cross-sectional profile (1) for a flat key or the keyway of a cylinder lock, comprising a back surface (2), a first lateral surface (4) and a second lateral surface (4′), wherein the lateral surfaces (4, 4′) extend in the vertical direction to the back surface (2), the lateral surfaces (4, 4′) are arranged offset to one another by a distance (5), which varies along their extension, and the outline of the cross-sectional profile (1) defines a preferably substantially rectangular base profile (6), and wherein the lateral surfaces (4, 4′) each extend at least in sections along sinusoidal profiling lines (7, 7′), wherein the centerlines (8, 8′) of the profiling lines (7, 7′) lie within the base profile (6). Further, the invention relates to a flat key (16) with such a cross-sectional profile (1) and a cylinder lock with a keyway (13) for receiving such a flat key (16).