Pivot Hinge Guide Pin Tensioning for Frictional Stability
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Solution Overview
Problem
Prior art pivotal window hinges face instability in intermediate positions, especially at low roof angles with large opening angles, due to insufficient friction, and tend to deteriorate from guide pin scraping on the leaf spring, leading to reduced hinge friction.
Innovation Solution
The hinge incorporates a guide pin with a tensioning projection and convex side that maintains frictional engagement with the leaf spring, reducing stress spikes and deterioration, and a leaf spring with an elbow portion and multiple curved sections for enhanced frictional engagement, along with a non-rotatably mounted guide pin for consistent orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the guide pin is allowed to rotate freely during pivoting movement, then the hinge structure is simpler, but the frictional engagement with the leaf spring becomes inconsistent and insufficient
Solution Approach 1:
The guide pin is pre-mounted in a fixed, non-rotatable position on the second base plate before operation. This preliminary positioning ensures that the convex side and tensioning projection maintain consistent frictional engagement with the leaf spring throughout the pivoting movement, eliminating the instability that would occur with free rotation.
Solution Approach 2:
The guide pin is designed with asymmetric features including a convex side and a tensioning projection, creating different local qualities on different surfaces. The convex side provides continuous frictional engagement while the tensioning projection maintains spring stress, ensuring reliable frictional stability without requiring complex additional components.
2Productivity
If the slide bar enters the guide at high speed from a large opening angle, then the closing operation is faster, but stress spikes occur and accelerate deterioration
Solution Approach 1:
The tensioning projection on the guide pin preliminarily engages and stresses the leaf spring before the slide bar enters the guide. This preliminary action pre-loads the spring, creating a cushioning effect that absorbs the impact when the slide bar enters at high speed, thereby preventing stress spikes and reducing deterioration.
Solution Approach 2:
The leaf spring is pre-stressed by the tensioning projection before the slide bar engagement, creating a cushioning effect. This beforehand cushioning prepares the spring to absorb the impact energy of rapid closing operations, protecting the hinge components from damaging stress spikes while maintaining fast closing speed.
3Ease of operation
If the leaf spring has minimal frictional engagement with the engagement set, then the hinge operates more smoothly, but intermediate positions become unstable and unintentional pivoting occurs
Solution Approach 1:
The leaf spring is designed with an elbow portion that creates a specific local geometry for frictional engagement. This elbow portion, combined with the guide pin's convex side and tensioning projection, creates an optimized friction interface that provides sufficient friction to stabilize intermediate positions while maintaining smooth pivoting operation through the engineered contact surfaces.
Solution Approach 2:
The frictional engagement parameters are optimized by changing the geometry of the leaf spring (adding the elbow portion) and the guide pin (adding convex side and tensioning projection). These parameter changes adjust the coefficient and distribution of friction to achieve the optimal balance between smooth operation and intermediate position stability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design improves frictional stability across more intermediate positions, reduces the hinge's deterioration rate, and maintains sufficient friction to prevent unintentional pivoting, even at low roof angles, while ensuring the hinge's operational longevity.
Implementation Method 1
The leaf spring is, during at least a part of the pivoting movement, in a frictional engagement with at least one element of the engagement set of the second hinge part
Implementation Method 2
the guide pin, potentially the convex side of the guide pin, is able to remain in a frictional engagement with the leaf spring during the pivoting movement of the window
Data Source
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AI summary
The hinge is intended for use in a pivotal window with a frame and a sash connected to the frame by providing a pivoting movement for the window about a hinge axis. A first hinge part (1) to be secured on the frame and including a first base plate (2), a braking device with a leaf spring (15), and control means in the form of an arc shaped, preferably circular-arc shaped, guide (7); and a second hinge part (3) to be secured on the sash and including a second base plate (4) and an engagement set with a slide bar (8) and a guide pin (10). The arc shaped guide (7) cooperates with the engagement set, the slide bar (8) being adapted to fit in the guide (7) and being rotationally mounted on the second base plate (4), the guide pin (10) being mounted on the second base plate (4), and the leaf spring (15) is, during at least a part of the pivoting movement, in a frictional engagement with at least one element of the engagement set of the second hinge part (3). The guide pin (10) comprises a tensioning projection (10a) and an adjoining convex side (10c).