Window Sash Bayonet Coupling for Tool-Free Secure Hinge Assembly
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Solution Overview
Problem
Existing fitting arrangements for tilt-and-turn sashes are difficult to install, require tools, and risk detachment due to loose connections, especially with bayonet fittings.
Innovation Solution
A bayonet fitting system with a rigidly attached bayonet bolt on the bearing band or carrying handle, requiring a specific rotational alignment to ensure secure coupling, eliminating the need for tools and preventing accidental disengagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a bayonet fitting is used to connect the pivot arm to the bearing band, then the connection can be made without tools, but the connection may loosen over time due to vibration and operation
Solution Approach 1:
The patent applies preliminary action by providing a chamfer on the bearing band that automatically guides and aligns the bayonet bolt during insertion. This preliminary alignment action ensures the bolt engages correctly before operation begins, preventing misalignment-induced loosening during subsequent use.
2Adaptability or versatility
If the pivot arm and bearing band are manufactured separately for flexibility, then different configurations can be used, but the coupling between parts must be extremely reliable to prevent detachment
Solution Approach 1:
The patent applies composite materials by using a multi-material construction for the coupling mechanism: the bearing band is made of a first material while the bayonet bolt is made of a second material with different thermal expansion characteristics. This composite approach allows the separate parts to remain reliably coupled under varying thermal and mechanical conditions while maintaining configuration flexibility.
Solution Approach 2:
The patent applies spheroidality by providing a chamfer (an angled, curved surface) on the bearing band that guides the bayonet bolt into proper alignment. This curved surface geometry ensures reliable coupling engagement while allowing the separate parts to be manufactured independently for flexible configuration.
3Ease of operation
If a rotating bayonet bolt is used for connection, then assembly is simplified, but the bolt may be forgotten to be turned or may loosen due to vibration
Solution Approach 1:
The patent applies preliminary action by pre-configuring the chamfered bearing band to automatically guide and lock the bayonet bolt in the correct position during insertion. This preliminary guiding action eliminates the need to remember to manually turn the bolt, as the chamfer automatically performs the alignment and engagement function.
Solution Approach 2:
The patent applies the intermediary principle by introducing the chamfer as a mediating feature between the bearing band and bayonet bolt. This intermediate geometric feature facilitates reliable connection by automatically guiding the bolt into proper alignment, serving as a mediator that prevents both forgetting to turn the bolt and loosening due to vibration.
Data Source
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AI summary
A fitting arrangement for the sash of a window, door or the like comprises a pivot arm designed to be attached to the sash and having, at a hinge-side end of its longitudinal extension, a support bracket with a leg angled transversely to the longitudinal extension; the fitting arrangement further comprises a bearing hinge designed to be pivotably mounted about an axis of rotation of a pivot bearing to be provided on the frame of the window or door with a bearing section, and having a coupling section that can be coupled to the angled leg of the support bracket of the pivot arm by means of a bayonet fitting.The bayonet fitting comprises a bayonet bolt extending along a bolt axis and a bayonet receptacle, both designed such that, to close the bayonet fitting, the bayonet bolt is inserted axially into the bayonet receptacle with respect to the bolt axis and then rotated relative to the bayonet receptacle around the bolt axis into a coupling position. In this position, the positive locking means of the bayonet bolt engage corresponding positive locking means of the bayonet receptacle, thereby preventing the bayonet bolt from axially exiting the bayonet receptacle. The bayonet bolt is rigidly mounted to the carrying handle or the bearing band.