Furniture Ejector Friction Clutch With Direction-Dependent Torque
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Solution Overview
Problem
Existing ejection devices for furniture parts face issues of damage to the drive unit due to excessive force and potential blocking during the ejection process, lacking a compact design and effective torque regulation to prevent decoupling.
Innovation Solution
Integration of a slipping clutch within the lever, utilizing a spring mechanism that adjusts overlocking torque based on direction of rotation, allowing for increased torque during ejection and reduced torque during return, preventing damage and ensuring proper operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a slipping clutch is integrated into the lever, then device complexity is reduced and compact design is achieved, but torque regulation capability may be compromised
Solution Approach 1:
The slipping clutch is integrated directly into the lever structure, merging the clutch function with the lever body. This eliminates separate clutch components and reduces overall device complexity while maintaining the torque decoupling function through the spring mechanism embedded in the lever.
Solution Approach 2:
The spring mechanism within the slipping clutch dynamically adjusts the coupling between drive unit and ejector based on torque conditions. During ejection, the spring maintains coupling; during return or overload, the spring allows decoupling, providing adaptive torque regulation without complex control systems.
2Reliability
If overlocking torque is set high during ejection, then ejection reliability is improved, but drive unit damage risk increases during return process
Solution Approach 1:
The slipping clutch operates with different torque thresholds during different phases of the cycle: high overlocking torque during ejection prevents slippage and ensures reliable operation, while low overlocking torque during return allows easy decoupling to prevent damage. The spring mechanism automatically transitions between these states based on rotation direction.
Solution Approach 2:
The spring mechanism is designed to behave differently in opposite rotation directions: during ejection (forward rotation), the spring maintains tight coupling with high torque transfer; during return (reverse rotation), the spring allows slippage at low torque, inverting the normal torque transmission behavior to protect the drive unit.
3Force
If spring diameter is reduced to increase coupling force, then overlocking torque increases, but spatial requirements may be compromised
Solution Approach 1:
The spring parameters (diameter, wire thickness, coil density) are optimized to achieve the required coupling force within the available space. A smaller diameter spring with increased wire thickness or adjusted coil density provides high coupling force during ejection while maintaining compact dimensions suitable for integration into the lever structure.
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
The solution provides a compact design that prevents drive unit damage by dynamically adjusting torque, ensuring safe and efficient ejection and return of furniture parts without external force transmission during the return process.
Implementation Method 1
a spring (9) arranged to interact with the two parts (7, 8) in such a way that, when the two parts are rotated in a first of the two directions of rotation, the diameter of the spring decreases
Implementation Method 2
when the two parts are rotated in a second of the two directions of rotation, the spring expands
Data Source
Figure 1
Figure 2~3
Figure 4a~4b
AI summary
Ejection device for a furniture part mounted movably in or on a furniture body, with an ejector, with a drive unit and a friction clutch, wherein the friction clutch is designed in such a manner that it decouples the drive unit and the ejector from each other when a predetermined torque is exceeded, wherein the friction clutch (6) comprises two parts (7, 8) which are rotatable in relation to each other with respect to two directions of rotation, wherein a spring (9) is provided which interacts with the two parts (7, 8) in such a manner that the torque at which the decoupling takes place differs for the two directions of rotation of the two parts (7, 8).