Retracting device
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing self-closing drawer mechanisms require minimal force to close but generate uncomfortable restoring forces when opening, and previous designs either increase friction, require additional space, or are costly due to unnecessary path-dependent force and deflection.
Innovation Solution
A retraction device using a combination of at least two springs, including a tension spring and a compression spring, arranged concentrically or in a cascaded manner to minimize restoring forces and maintain a compact design, with the option of using spiral springs for increased deflection in a small space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a single spring is used in the self-closing mechanism, then the restoring force increases path-dependently when the furniture part is opened, but this creates uncomfortable pull-out forces for the user
Solution Approach 1:
The single spring is segmented into multiple springs (first spring and second spring) that are coupled together. This segmentation allows the total spring deflection to be distributed across multiple components, reducing the path-dependent force increase that occurs with a single long spring.
2Ease of operation
If a longer spring is used to reduce restoring forces, then the pull-out force comfort improves, but additional frictional forces act on the spring and additional space is required transversely
Solution Approach 1:
The first spring and second spring are arranged concentrically, with one spring nested inside the other. This nesting arrangement allows multiple springs to occupy the same transverse space, reducing the overall footprint while maintaining the benefits of distributed spring deflection.
3Ease of operation
If a longer spring is used to reduce restoring forces, then the pull-out force comfort improves, but additional frictional forces act on the spring
Solution Approach 1:
By segmenting the spring system into multiple shorter springs coupled together, the total deflection is distributed. Each individual spring experiences less deflection and thus generates fewer frictional forces against its guides, while still achieving the overall force reduction benefit.
4Ease of operation
If multiple springs are used to reduce restoring forces, then the pull-out force comfort improves, but the device complexity increases
Solution Approach 1:
The concentric arrangement of multiple springs within a common guide structure simplifies the overall device complexity. Instead of requiring separate guides and mounting points for each spring, the nested configuration allows multiple springs to share the same spatial envelope and guidance system.
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 reduces path-dependent restoring forces, minimizes discomfort during opening, and achieves a compact, cost-effective design by distributing the spring deflection evenly, resulting in a smaller overall spring constant and reduced assembly complexity.
Implementation Method 1
a compression spring (6) arranged around a tension spring (7), wherein the compression spring (6) is supported on the housing (2) on one side and coupled to a connecting piece (9) on the other side, which in turn is connected to the tension spring (7)
Implementation Method 2
at least one spring is designed as a tension spring and at least one spring as a compression spring
Data Source
Figure 1
Figure 2A~2C
Figure 3A
AI summary
The invention relates to a retracting device, in particular for drawers, comprising a housing (2) on which a driver (3) is guided, wherein said driver (3) is movable from a drawing-in to a parking position against a spring force and is coupled to a closable furniture part for holding it in the closed position thereof. According to said invention, the driver (3) is prestressed in the drawing-in position by means of at least two springs (6, 7, 16) which are coupled therebetween by means of a connecting part (9, 9', 90). The use of individual springs (6, 7, 16) makes it possible to obtain an important spring path for a compact structure.