Multi-link hinge with linear damper for controlled door closure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-joint hinges often cause doors to slam shut uncontrollably due to spring bias, leading to uncontrolled closure.
Innovation Solution
A linear damper is integrated into the hinge mechanism, effective only in the closing range just before the door reaches the closed position, combined with a spring that supports the closing movement and provides freewheeling in the open position, ensuring smooth operation and preventing uncontrolled slamming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a spring is used to pre-tension the multi-joint hinge into a closed position, then the door hinge can be automatically closed, but the door may slam shut uncontrollably
Solution Approach 1:
A linear damper is introduced as an intermediary element between the door and the hinge mechanism. The damper includes a piston rod displaceable in an elongated hole, creating a fluid-resistant intermediary that controls the closing speed. This mediator allows the spring's closing force to be applied while preventing uncontrolled slamming through viscous damping.
Solution Approach 2:
The damping parameter is made variable through the elongated hole geometry. The hole is positioned and dimensioned such that the piston rod engages the damping effect only in the closing range (20°-40° from closed position), while allowing free movement in the open position. This changes the damping parameter from constant to position-dependent, enabling controlled closing without affecting opening smoothness.
2Reliability
If a damper is mounted to dampen the closing movement, then slamming is prevented, but the damping may create stiffness during opening movement
Solution Approach 1:
The damping effect is localized to specific angular ranges rather than being applied throughout the entire pivot range. The elongated hole is positioned so that the piston rod engages the damping mechanism only when the door is within 20°-40° of the closed position. In the open position, the piston rod moves freely within the elongated hole, creating no resistance and maintaining smooth opening movement.
3Reliability
If the damper is effective over the entire pivot range, then closing control is improved, but the user may perceive bothersome stiffness during opening
Solution Approach 1:
The damping action is made periodic rather than continuous. The piston rod alternates between engaging the damping effect (when the door approaches closed position) and moving freely (when the door is open or during opening). This periodic engagement/disengagement pattern ensures controlled closing while maintaining perceived smoothness during opening operations.
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 damper effectively reduces the closing speed of the door near the closed position, preventing slamming while allowing smooth opening and closing movements, enhancing user experience by ensuring a controlled and gentle door closure.
Implementation Method 1
The damping effect of the damper is intended to be effective only in the area just before the closed position... a linear damper with a plunger is mounted on an intermediate piece which is fixed to a hinge arm
Implementation Method 2
the spring can pre-tension the door hinge into the closed position and assist the closing movement within a pivot range that is larger than the pivot range in which the damper is effective
Data Source
Figure 1~1B
Figure 2~2B
Figure 3~3B
AI summary
A multi-joint hinge (1), particularly for refrigerator doors, comprises a fastening element (2) that can be fixed to a furniture body. This fastening element connects several scissor-like levers (3, 4, 5, 10) to a pivotable door bearing (11), the door bearing (11) being biased into a closed position by a spring (15). A linear damper (18) is provided to dampen the closing movement of the door bearing (11), acting at least over a portion of the pivot range of the door bearing (11). This assists the closing movement and prevents the door coupled to the door bearing (11) from slamming shut.