Self-retracting device for a pull-out furniture part
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing self-retracting devices for furniture parts face challenges in achieving an advantageous force curve with a large retraction distance and small installation space, leading to uneven forces required for operation and locking, and increased installation space requirements.
Innovation Solution
A self-retracting device where the retraction spring is connected to the carriage via a pivotally mounted arm, with its pivoting position guided by the base body, allowing the force exerted by the spring to be influenced along the driving path, increasing force at the beginning of pull-out and reducing it towards the end, and incorporating a tilting part and damper unit for enhanced functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the retracting spring is connected directly to the carriage, then the structure is simple, but the force distribution is uneven with significantly lower force at home position than at standby position
Solution Approach 1:
The patent introduces an arm as an intermediary component between the retracting spring and the carriage. This arm is pivotally mounted on the carriage and guided by the base body, allowing it to change its pivot position along the drive path. The arm acts as a force transmission mediator that modifies the spring force distribution, providing higher force at the beginning of retraction and lower force near the home position, thereby achieving more uniform force distribution without significantly complicating the overall structure.
2Ease of operation
If a lever system is used to increase spring force at basic position, then the force distribution improves, but the installation space requirement increases significantly
Solution Approach 1:
The patent employs a dynamic arm mechanism that changes its configuration along the drive path. The arm is guided by the base body to assume different pivot positions depending on the carriage location. This dynamic adaptation allows the system to achieve favorable force distribution without requiring a large, fixed installation space. The arm's movement and changing geometry enable effective force multiplication only when needed, optimizing both force distribution and space utilization.
Solution Approach 2:
The arm is guided to change its pivot position in a direction perpendicular to the main drive path, utilizing the vertical dimension. This dimensional change allows the mechanism to achieve the desired force distribution while maintaining a compact horizontal footprint, effectively resolving the space constraint issue.
3Area of stationary object
If the pull-out guide rails are made shorter to reduce installation space, then the installation space decreases, but the load capacity is reduced due to less favorable roller position
Solution Approach 1:
The arm serves as a force transmission intermediary that compensates for the reduced mechanical advantage resulting from shorter guide rails. By strategically positioning the arm engagement point and guiding its movement, the system maintains effective force transmission and carriage support even with reduced rail length, thereby preserving load capacity while achieving compact installation space.
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 achieves a more uniform and reduced force requirement for operation, supports complete retraction, and optimizes the installation space, improving user experience and load capacity.
Implementation Method 1
a retracting spring (13) which urges the carriage (6) into the home position, which engages at a first end at a base body engagement point (14) on the base body (5) and of which the second end is operatively connected to the carriage (6)
Implementation Method 2
a damper unit (12) which reduces the speed of the carriage (6)
Data Source
Figure 1~5
Figure 6
Figure 7~9
AI summary
A self-closing device for a furniture part that can be extended from a furniture carcass (50) by means of a pull-out guide, comprising a base body, a slide (6) slidably mounted on or in the base body (5), and a retraction spring (13) that acts on the slide (6) in a home position. The retraction spring (13) is connected to the slide (6) via an arm (7) which is pivotably mounted on the slide (6) about a pivot axis (8) and on which the second end of the retraction spring (13) engages at a distance from the pivot axis (8), wherein the arm (7) is guided with respect to its pivot position about the pivot axis (8) when the slide (6) is moved from the base body (5), and the pivot position of the arm (7) about the pivot axis (8) changes when the slide (6) is moved.