Lift-off Hinge with Rotating Pin for Secure Door Removal
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Solution Overview
Problem
Conventional lift-off hinges allow doors or windows to be easily removed when closed, compromising security by bypassing locks, as they do not effectively prevent lifting off in the closed position.
Innovation Solution
A hinge design featuring a pin and receptacle with cooperating projections that allow separation in an open position but obstruct separation in a closed position, utilizing a beak and arcuate features to secure the door when closed and permit lifting off when open.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional lift-off hinge is used, then the door can be easily removed when open to facilitate work or improve access, but the door can also be easily removed when closed which compromises security
Solution Approach 1:
The hinge transitions from a static connection to a dynamic one where the pin can rotate within the receptacle. When the door is open, the pin rotates to align the lift-off groove with the loop, permitting removal. When closed, the pin position obstructs the groove, preventing removal. This dynamic behavior resolves the contradiction between ease of operation and security.
Solution Approach 2:
The hinge is divided into two independent parts: a pin and a receptacle. This segmentation allows each component to have specialized features (lift-off groove in pin, protrusion in receptacle) that work together to provide conditional removal capability - easy removal when open, secure when closed.
2Ease of manufacture
If the hinge allows easy lifting off when open, then work on door or equipment is facilitated, but the same mechanism allows unauthorized removal when closed
Solution Approach 1:
The hinge mechanism creates different local conditions for door removal based on door position. In the open position, the geometry of the pin and receptacle creates a clear path for loop removal. In the closed position, the relative positioning creates obstruction. This local quality differentiation resolves the contradiction between ease of work and prevention of unauthorized removal.
3Device complexity
If a simple lift-off hinge design is used, then the hinge is robust and easy to manufacture, but it cannot prevent lifting off in closed position
Solution Approach 1:
The hinge solution adds a rotational dimension to the otherwise simple lift-off mechanism. The pin rotates within the receptacle to change the alignment between the lift-off groove and the loop. This dimensional change allows the simple robust design to gain the capability of preventing lifting in closed position while maintaining ease of manufacture.
Data Source
AI summary
An embodiment of a hinge has a first part with a pin, the pin defining a longitudinal axis, and a second part with a receptacle for the pin. The first and second parts are arranged to rotate relative to one another about the axis with the pin in the receptacle. Mutually cooperating formations on the pin and receptacle are arranged to permit separation of the first and second parts along the axis in a first position of relative rotation of the first and second parts and to obstruct separation of the first and second parts along the axis in a second position of relative rotation of the first and second parts.