Skylight Burglar-Proof Locking Device with Snake-Eye Cap
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Solution Overview
Problem
Existing skylight and roof window locking devices are either insecure or complicated, allowing burglars easy access and requiring multiple tools for installation and removal, which increases time and complexity.
Innovation Solution
A burglar-proof locking device that integrates a cap with sloping sides and a snake-eye notch, allowing secure attachment and detachment with a special tool, reducing the need for a second fastener and preventing access with ordinary tools.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard screw or bolt is used to fasten the weather shield to the sash, then the installation is simple and uses common tools, but the locking device is insecure and allows easy access for burglars
Solution Approach 1:
The locking device employs a nested structure where the cap is screwed onto the screw, with the cap's interior thread receiving the screw's exterior thread. The locking means is positioned inside the cap, creating a nested arrangement of components within a compact space, which provides security without excessive complexity
Solution Approach 2:
The cap serves as an intermediary element between the screw and the weather shield. It has a sloping outer surface that prevents direct tool access to the screw head, while still allowing the screw to fasten the weather shield securely. This intermediary structure blocks burglar access while maintaining fastening functionality
2Reliability
If a cap with sloping sides is added to prevent tool access, then security is improved, but the device becomes more complicated and voluminous
Solution Approach 1:
The locking device is segmented into distinct functional components: the screw for fastening, the cap for security and tool access control, and the locking means for final securing. This segmentation allows each component to be optimized for its specific function while maintaining a compact overall volume
Solution Approach 2:
The cap is designed to screw onto the screw, with the locking means positioned inside the cap. This nested arrangement minimizes the overall volume of the locking device while maintaining all necessary security features, avoiding the need for separate bulky components
3Reliability
If two separate fasteners (screw and cap) are used, then security is improved, but the installation time is doubled and requires multiple tools
Solution Approach 1:
The screw and cap are designed to work together as an integrated fastening system. The cap screws onto the screw in a single continuous motion, and the locking means is activated as part of the same fastening process. This merging of functions allows the entire security fastening operation to be completed with one tool and in one continuous action, eliminating the need for separate installation steps
4Reliability
If the cap has sloping sides to prevent wrench engagement, then security is improved, but the cap requires additional supporting construction to withstand radial forces
Solution Approach 1:
The cap is designed with sloping sides only in the regions where tool access needs to be prevented, while maintaining adequate thickness and structural support in areas where radial forces are applied. This localized approach to geometry allows the cap to provide security features without requiring excessive supporting construction throughout the entire component
Solution Approach 2:
The cap is pre-formed with the sloping outer surface during manufacturing, eliminating the need for additional supporting construction to be added later. The sloping geometry is integrated into the cap's basic structure, providing security features without requiring separate reinforcing elements
Data Source
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AI summary
A burglar-proof locking device for fastening a light dome to a sash member of a skylight or roof window, comprising a locking member having a first and a second end, which first and second ends are positioned along a longitudinal axis of said locking member, said first end projecting outwardly from said locking device and being connected with a locking means adapted to rotate into engagement with a corresponding locking means of said sash member. Said second end of said locking member provides an engagement means, such as a snake-eye notch, adapted for engagement with a special tool, such as a tool comprising a snake-eye projection, said engagement means being surrounded by a cap with a centre aperture allowing for insertion there-through of said special tool into said engagement means for rotation of said locking device, said cap otherwise covering said second end of said locking member, said cap being freely rotatable about said longitudinal axis in relation to said locking member such as to prevent rotation of said locking member without use of said special tool.