Window Sash Drive Mechanism with Cam Linkage for Force Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing devices for opening and closing windows or doors face challenges with low force transmission near the dead center position, requiring additional locking mechanisms and powerful motors to ensure secure sealing and efficient operation, which increases complexity and power consumption.
Innovation Solution
A connecting link is introduced that supports the sash against the frame during the initial partial stroke, allowing for favorable force conditions and efficient opening and closing movements with a smaller motor, featuring a pivotable arm and link follower mechanism that engages with the drive element to facilitate easy movement and sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If scissor hinges are used to open the sash, then the movement direction can be redirected to match the spindle drive, but the force transmission becomes very low near the dead center position
Solution Approach 1:
The opening/closing movement is divided into two distinct phases: a first partial stroke where the drive element moves independently to build favorable force conditions, and a second partial stroke where the output element engages to complete the movement. This segmentation allows the system to avoid the dead center position problem by establishing proper force conditions before engagement.
Solution Approach 2:
The drive element performs a preliminary partial stroke movement before the output element engages. This preliminary action positions the connecting link and extension arm in favorable geometric conditions, ensuring that when the output element engages, the force transmission is optimal and the sash can be effectively accelerated and pushed away from seals.
2Reliability
If additional locking mechanisms are added to ensure secure sealing at dead center position, then the sealing reliability improves, but the device complexity increases
Solution Approach 1:
The invention extracts and eliminates the dead center position from the mechanism's operation by using a connecting link with specific geometric relationships. The link is designed so that its center lines with the extension arm and drive element never converge to a dead center position, thereby removing the need for additional locking mechanisms while maintaining secure sealing.
Solution Approach 2:
The mechanism uses dynamic geometric relationships where the connecting link's orientation and position change continuously during operation. This dynamic configuration ensures that the force transmission angle remains favorable throughout the movement, providing both secure sealing and smooth operation without requiring static locking mechanisms.
3Reliability
If a joint is positioned eccentrically on the extension arm to generate extension movement, then the dead center position is avoided, but the force transmission becomes unfavorable at the beginning of movement and manufacturing complexity increases
Solution Approach 1:
The connecting link serves as an intermediary element between the drive element and the extension arm. It mediates the force transmission by maintaining favorable geometric relationships throughout the movement, avoiding the need for eccentric joint positioning while still preventing dead center conditions and ensuring good force transmission at all times.
4Ease of operation
If more powerful motors are used to overcome low force transmission, then the opening and closing capability improves, but the motor size and power consumption increase
Solution Approach 1:
The invention changes the geometric parameters of the mechanism, specifically the positioning and orientation of the connecting link, to optimize force transmission. By carefully designing the link's geometry and its relationship to the drive element and extension arm, the system achieves favorable force conditions throughout the movement, allowing the use of smaller, more energy-efficient motors.
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 solution enables safe, rapid, and energy-efficient pivot opening of the window with minimal motor power and size, overcoming the limitations of low force transmission and complex arrangements in existing technologies.
Implementation Method 1
A cam mechanism into which the drive element engages during the partial stroke, achieving support of the sash against the frame perpendicular to the direction of movement of the drive element
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a device (3) for opening and/or closing a sash (2) relative to a frame (1), in particular for casement sashes, comprising: a movable drive element (7) for generating a drive movement, an output element (9) connected to the drive element (7) for moving the sash (2) in such a way that the drive element (7) performs a partial stroke moving relative to the output element (9) and a working stroke moving together with the drive element (9), wherein the connection between the drive element (7) and the output element (9) comprises a locking or coupling element (17) to detachably secure the drive element (7) to the output element (9) at one end of its partial stroke.In order to achieve a safe and rapid pivoting opening of the wing with the smallest motor dimensions and power consumption, a cam (15) is provided into which the drive element (7) engages during the partial stroke and achieves a support of the wing (2) against the frame (1) directed transversely to the direction of movement of the drive element (9).