Pull-Closed Lever Geometry for Strong Sealing and Easy Opening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing closing devices for movably mounted furniture parts struggle to achieve a high closing force while allowing easy opening, which is essential for maintaining a reliable seal, especially in applications like refrigerated cabinets where climate differences exist.
Innovation Solution
The closing device employs a driver with a distance from the pivot axis of the closing lever that is at least 1.5 times larger than in its closed position, combined with a curved guide track and a closing spring design that increases tension, allowing a high closing force to be exerted with a small force required to pivot the lever from the waiting to the locking position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a closing device uses a spring-loaded mechanism to automatically retract the furniture part, then the furniture part can be automatically closed, but the closing force may not be sufficient to maintain a reliable seal
Solution Approach 1:
The guide track is designed with a curved geometry instead of a straight line. The curvature allows the driver to follow a path that maximizes the lever arm distance from the pivot axis during the closing operation, thereby amplifying the closing force exerted by the spring mechanism on the furniture part.
Solution Approach 2:
The solution transitions from a simple linear guide track to a two-dimensional curved guide track. This dimensional change in the guide track geometry enables the driver to achieve greater distance from the pivot axis at critical points in the closing motion, increasing the mechanical advantage and closing force without adding complexity to the basic mechanism.
2Force
If the driver is positioned far from the pivot axis to increase closing force, then the closing force is improved, but the opening operation becomes more difficult
Solution Approach 1:
The guide track is designed to dynamically adjust the driver's position relative to the pivot axis throughout the motion cycle. During closing, the curved track positions the driver far from the pivot axis to maximize closing force. During opening, the track geometry naturally guides the driver through a path that reduces the opposing moment, making opening easier despite the high closing force capability.
Solution Approach 2:
The guide track creates a periodic variation in the lever arm length during the open-close-open cycle. The curved geometry ensures that the driver achieves maximum distance from the pivot axis only during the closing phase, while during opening and when fully open, the driver is positioned closer to the pivot axis, reducing the force required for opening operations.
3Device complexity
If a linear guide track is used for the driver, then the mechanism is simple, but the closing force in the closed position is insufficient
Solution Approach 1:
The guide track is designed with a curved geometry instead of a straight line. The curvature allows the driver to follow a path that maximizes the lever arm distance from the pivot axis during the closing operation, thereby amplifying the closing force exerted by the spring mechanism on the furniture part.
Solution Approach 2:
The guide track geometry is specifically designed to change the positional parameters of the driver during motion. The curved track ensures that at the closed position, the driver achieves an optimal distance from the pivot axis that maximizes the closing force, while maintaining a relatively simple overall track design that does not require complex mechanisms to achieve.
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 configuration enables a high closing force in the closed position for maintaining a seal while allowing easy opening, with a force-displacement diagram showing a high closing force in the closed state and a low energy requirement for opening, enhancing user experience and operational efficiency.
Implementation Method 1
a closing spring (17), which acts on the bearing unit (9) on the one hand and on the closing lever (15) on the other hand
Implementation Method 2
The pivoting of the closing lever (15) from the waiting position into the locking position is dampened by at least one damper (21, 22)
Data Source
Figure 1~3
Figure 4
Figure 5~7a
AI summary
A pull-closed device for a movably mounted furniture part (4) which, starting from a closing position in which a contact surface of the movable furniture part (4) rests on a carcass part (2), can be opened to an open position, comprises a carrier (8), which can be connected to the movable furniture part (4) or to the carcass part (2), and a pull-closed lever (15) which is impinged upon by a pull-closed spring (17), said pull-closed lever (15) having a guide track (18) for the carrier (8) and being pivotable by the carrier (8) when the movable furniture part (4) is opened between a hold-closed position, which the pull-closed lever (15) assumes when the movable furniture part (4) is in the closing position and in which the carrier (8) is in a closed position in the guide track (18), and a standby position, in which the carrier (8) uncouples from the pull-closed lever (15), about a stationary pivoting axis (16) which is stationary with respect to the carcass part (2) when the carrier (8) is connected to the movable furniture part (4), or which is stationary with respect to the movable furniture part (4) when the carrier (8) is connected to the carcass part (2). When the movable furniture part (4) is closed, a pull-closed force can be exerted by the pull-closed lever (15) onto the carrier (8) as of a use position assumed by the carrier (8) in the guide track (18). The distance (a) of the carrier (8) in the use position from the pivoting axis (16) of the pull-closed lever (15) is at least 1.5 times, preferably 2 times, as large as the distance (a) of the carrier (8) in the closed position from the pivoting axis (16) of the pull-closed lever (15).