Door Fitting Locking Mechanism Prevents Unauthorized Removal
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Solution Overview
Problem
Existing door fittings lack a secure method to prevent unauthorized disassembly from the outside when the door is closed, especially in pipe frame doors where additional openings for screws or threaded bolts are not available, posing security and fire protection concerns.
Innovation Solution
A door fitting with an outer fitting part featuring a projection or undercut mechanism that engages with a corresponding element, combined with a component like a square pusher pin or locking cylinder, which prevents movement relative to the engagement element, ensuring the fitting cannot be disassembled without access to the inside, using existing door openings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If screws or threaded bolts are used to secure the exterior hardware component, then the component is secured against unauthorized removal, but additional openings extending from the inside to the outside through the door are required
Solution Approach 1:
The fastening system is divided into two independent parts: a first engagement element fixed to the door and a second engagement element on the exterior hardware component. This segmentation allows each element to be mounted separately using existing openings, eliminating the need for additional openings while maintaining security.
Solution Approach 2:
The engagement elements act as intermediaries between the door and the exterior hardware component. Instead of directly fastening the component to the door through openings, the engagement elements mediate the connection, allowing secure attachment while preserving door integrity.
2Ease of operation
If the exterior hardware component is made easily removable, then installation and maintenance are simplified, but security against unauthorized disassembly is compromised
Solution Approach 1:
The fastening system transitions from a static permanent fastening to a dynamic system that can be easily engaged and disengaged. The movable engagement element allows the hardware component to be quickly installed and removed by those with authorization, while still providing security against unauthorized removal through its design.
3Reliability
If additional openings are created in the door for mounting purposes, then secure fastening is achieved, but fire safety and structural integrity are compromised
Solution Approach 1:
The engagement elements can be mounted using existing openings in the door that serve other functions (such as openings for square spindles or lock cylinders). This multi-functional use of existing openings provides secure fastening without creating additional openings that would compromise fire safety or structural integrity.
Data Source
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AI summary
A door fitting (10) comprises an external fitting part (30) for mounting on an outer surface (2) of a door (1) and a locking mechanism to prevent unauthorized removal of the external fitting part (30) from the outer surface (2) of the door (1). The locking mechanism comprises a first engagement element (21) that can be fixed to the outer surface (2) of the door (1) and a second engagement element (31) that is arranged on the external fitting part (30). One of the engagement elements (31) has an undercut (31) and the other of the engagement elements (21) has a projection that can be inserted into the undercut (31). The locking arrangement includes a component (40) which, in the mounted state of the door fitting (10), prevents relative movement between the outer fitting part (30) and the first engagement element (21) by means of a positive locking connection in order to secure the projection in the undercut (31).