Tool Handle Coupler Alignment to Prevent End Effector Loosening
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Solution Overview
Problem
Tools with threaded connections between handles and end effectors often experience loosening due to unequal forces applied to wider end effectors, leading to instability during use.
Innovation Solution
A secure connection system using a fitting and coupler with threaded and glued attachments, along with a clip to prevent rotation, ensures a stable and firm attachment of the end effector to the handle, utilizing a ramp and stopper mechanism for alignment and a pin and arms clip for additional stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a threaded connection is used to attach the end effector to the handle, then the tool can be shipped in a compact form, but the end effector tends to loosen from the handle during use due to unequal forces
Solution Approach 1:
The connection system is divided into multiple functional components: a fitting with internal threads, a coupler with external threads, alignment features (ramp and stopper), and a securing mechanism (clip with pin and arms). This segmentation allows each component to perform its specific function while working together to prevent loosening under unequal forces.
Solution Approach 2:
The alignment features (ramp and stopper) are designed to automatically align the diametrical passages of the fitting and coupler before the final tightening occurs. This preliminary alignment ensures that the pin can be properly inserted through both passages to secure the connection, preventing misalignment that would lead to loosening during use.
2Reliability
If a simple friction fitting or screw connection is used, then the structure remains simple, but the connection is not secure enough under unequal forces applied to wider end effectors
Solution Approach 1:
The invention merges multiple connection mechanisms into a single integrated system: threaded connection for primary attachment, alignment features (ramp and stopper) for precise positioning, and a clip with pin for rotational restraint. This combination creates a secure attachment that can withstand unequal forces while maintaining reasonable structural complexity.
Solution Approach 2:
The coupler acts as an intermediary component between the fitting and the end effector. It provides external threads that mate with both the fitting's internal threads and the end effector's threaded hole, while also providing the second diametrical passage for alignment. This intermediary element secures the connection without requiring direct threading between the fitting and end effector.
3Productivity
If threaded connections are used to facilitate compact shipping, then storage efficiency improves, but the connection becomes prone to loosening under operational loads
Solution Approach 1:
The connection system incorporates dynamic elements that adapt to operational loads. The clip with its opposing arms can flex to accommodate the unequal forces applied to wider end effectors, while the pin maintains rotational restraint. This dynamic response allows the connection to remain stable under varying operational conditions while maintaining compact shipping capability.
Data Source
AI summary
A device and tool include a fitting and a coupler for joining a handle and an end effector such as a broom or mop so that the handle cannot twist with respect to the end effector. The first end of the fitting attaches to the handle. The first end of the coupler threads to the second end of the fitting, and its second end threads to the end effector. Both the fitting and coupler have diametrical passages. A stopper on the coupler will seat in a ramp in the fitting when the coupler and fitting are fully threaded together and the stopper reaches the end wall of the ramp so the user knows the coupler and fitting are aligned. A clip holds the diametrical passages of the fitting and coupler in alignment to prevent twisting.