Drawer Closing Mechanism With Variable Gear Force Transition
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Solution Overview
Problem
Self-closing drawer slides with latching members experience abrupt transitions in force, leading to jerky movements and noise due to consistent increase in spring force as the drawer approaches full closure, causing discomfort and potential shifting of contents.
Innovation Solution
A closing device incorporating a base, latching member, rack, gear, and biasing member that provides a mechanical advantage, reducing the rate of increase in biasing force as the drawer approaches full closure, and optionally includes a damper for smoother operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring with linear force increase is used in the latching member mechanism, then the drawer can be reliably closed and held in position, but the force transmission becomes abrupt and jerky at engagement/disengagement points
Solution Approach 1:
The patent applies the dynamics principle by making the force transmission ratio variable rather than constant. The latching member mechanism is designed so that the mechanical advantage changes dynamically during the drawer's movement cycle. Specifically, the force transmission ratio is higher when the drawer is near the closed position (providing stronger closing force) and lower when the drawer is near the open position (reducing jerky forces). This dynamic adjustment resolves the contradiction between reliable closure and smooth operation.
Solution Approach 2:
The patent implements parameter changes by modifying the mechanical advantage parameter of the latching member mechanism. The design allows the force transmission ratio to change as a function of the drawer's position. The mechanism incorporates geometric parameters (such as lever arm lengths or gear ratios) that vary during operation, transforming the linear spring force into a non-linear force profile that peaks near closure and diminishes near the open position, thereby eliminating the abrupt on-off feeling.
2Force
If the spring force increases consistently until the latching member reaches the end of its travel, then maximum closing force is achieved, but this results in abrupt transitions and noise
Solution Approach 1:
The patent uses the dynamics principle to create a variable force transmission system. The latching member mechanism is designed with changing mechanical advantage throughout its travel range. As the drawer approaches the closed position, the mechanism provides higher force multiplication to ensure reliable closure. As the drawer moves toward the open position, the mechanical advantage decreases, causing the spring force to be transmitted more gradually. This dynamic behavior maintains high closing force while reducing the abrupt transitions and associated noise and vibration at the extremes of travel.
3Adaptability or versatility
If a latching member with pin engagement is used, then the drawer can be controlled within a pre-selected range of motion, but high forces are transmitted to the user at engagement and disengagement points
Solution Approach 1:
The patent applies parameter changes by making the force transmission ratio a variable parameter rather than a constant. The latching member mechanism is designed so that the mechanical advantage changes continuously or in steps throughout the range of motion. When the drawer is near the closed position, the mechanism provides higher force multiplication to ensure reliable engagement and holding. When the drawer is near the open position, the mechanical advantage is reduced, which limits the peak forces transmitted to the user during engagement and disengagement events, while still maintaining the pre-selected range of motion control.
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 device ensures smooth and quiet operation by maintaining sufficient biasing force to keep the drawer closed while reducing the abrupt transition of forces, enhancing user experience and preventing content shifting.
Implementation Method 1
the rack and gear engagement provides a mechanical advantage that alters the biasing force applied to the latching member in a manner that does not correspond linearly to movement of the latching member
Data Source
Figure 1
Figure 2A~2C
Figure 3A~3B
AI summary
A closing device that includes a latching member that when moved a given distance utilizes a gear to affect a mechanical advantage that results in an end of a biasing member being moved less than the given distance. The biasing member is used in moving a first drawer slide member to a closed position relative to a second drawer slide member, and use of the gear and the resulting mechanical advantage provide a smoother transition when the first drawer slide member is engaged or disengaged from the closing device.