Gravity-Actuated Latch for Automatic Lid Release
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Solution Overview
Problem
Existing litter bins with manually actuated latches are difficult for automated handling equipment to empty and do not prevent unauthorized access, as they require separate latch actuation and can be opened by minor tilting or rocking.
Innovation Solution
A gravity-actuated latch system with a pendulous weight offset from the latch member's pivot axis, which only releases the lid when the bin is tilted sufficiently, allowing automatic opening for emptying while preventing unauthorized access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a manually actuated latch is used to secure the lid, then the lid is held firmly in place, but it becomes difficult to remove the lid and empty the litter bin
Solution Approach 1:
The latch transitions from a static manually actuated mechanism to a dynamic gravity-actuated mechanism that automatically responds to bin tilting. The pendulous weight shifts position based on bin orientation, causing the latch to engage or disengage automatically, thus adapting the locking behavior to the operational state of the bin.
Solution Approach 2:
The latch system performs its own actuation through gravitational force without requiring external manual intervention. The pendulous weight and spring mechanism work together to automatically secure and release the lid based solely on the bin's tilt angle, eliminating the need for separate latch operation.
2Reliability
If a manually actuated latch is used, then the lid can be secured, but automated handling equipment must perform separate latch actuation to empty the bin
Solution Approach 1:
The latch actuation function is merged with the bin tilting operation. The same gravitational force that causes the bin to tilt also automatically triggers the latch to release, combining two separate actions (tilting and latch release) into a single automatic response, thereby eliminating separate latch actuation steps.
Solution Approach 2:
The latch system automatically performs its own release function in response to bin tilting without requiring external actuation from automated handling equipment. The gravity-actuated mechanism self-regulates the locking and unlocking states based on the bin's operational orientation.
3Ease of operation
If the latch is sensitive to minor tilting, then it can be easily opened, but unauthorized users can lift the lid
Solution Approach 1:
The latch system uses a specific tilt angle threshold as a parameter to distinguish between legitimate emptying operations and unauthorized access. The pendulous weight and spring mechanism are configured so that only tilting beyond a predetermined angle triggers latch release, creating an angular parameter barrier that prevents casual or unauthorized opening.
Solution Approach 2:
The latch responds dynamically to the magnitude of bin tilting rather than any tilting. The gravity-actuated mechanism maintains engagement for small tilts (preventing unauthorized access) and only releases when a critical tilt threshold is exceeded (indicating intentional emptying operation).
4Reliability
If the pivot axis of the pendulous weight is offset from the pivot axis of the latch member, then the latch does not unlock with minor tilting, but the lid cannot be opened easily
Solution Approach 1:
The offset pivot axes create a dynamic mechanical advantage that changes with bin tilting. At small tilt angles, the geometric relationship between the offset pivots maintains strong latch engagement. As tilting increases, the mechanical advantage shifts, allowing the spring to overcome the catch portion and release the latch automatically at the threshold angle.
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
Enables easy emptying by automated equipment and secure access control, ensuring the lid is only opened when the bin is tilted past a threshold angle, enhancing operational efficiency and security.
Implementation Method 1
The latch is gravity-actuated, such that the lid is released when the litter bin is tilted sufficiently
Data Source
AI summary
A litter bin includes a lid hingeably connected to a container. Opposite the hinge, a latch selectively secures the lid to the container. The latch includes a pivotably mounted latch member. The latch member includes a catch portion that moves between a locked position and an unlocked position upon pivoting of the latch member. A weight is pivotably connected to the latch member at a point offset from the pivot axis of the latch member, thereby further retaining the catch portion of the latch member in the locked position. The litter bin must be tilted past a nonzero tilt threshold before the latch member pivots the catch portion from the locked position to the unlocked position.