Spring-Loaded Shaft Coupling Lock for Tool-Free Maintenance
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Solution Overview
Problem
Existing connection devices for shafts in transmission assemblies often require tools to unlock, making it difficult to access and repair components, especially when components seize, necessitating disassembly of multiple parts or cutting of shafts.
Innovation Solution
A connection device with a movable blocking pin, an elastic return member, and a manual actuating part allows for easy locking and unlocking without tools, using an oblong slot and spring mechanism to move the pin between locked and unlocked positions, visible color cues for operator guidance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a threaded hole with locking screw is used to secure the shaft connection, then the connection strength is improved, but the ease of operation deteriorates because tools are required to lock and unlock
Solution Approach 1:
The patent replaces the threaded screw locking mechanism with a spring-loaded pin system actuated by a lever. The spring provides automatic retraction and resetting, while the lever provides mechanical advantage for easy manual operation. This substitution eliminates the need for threaded holes and screwdrivers, achieving both strong connection and tool-free operation.
Solution Approach 2:
The spring-loaded pin automatically resets to the locked position after being actuated, providing self-service functionality. The system uses the spring's stored energy to automatically return the pin to its locking position without requiring additional manual intervention or tools, making the locking mechanism self-regulating.
2Reliability
If a locking screw extending into the radial groove is used, then the reliability of the connection is improved, but the ease of repair deteriorates when components seize and the screw becomes inaccessible
Solution Approach 1:
The patent extracts the actuating mechanism (lever) from the internal locking structure and positions it on the external surface of the connecting device. This allows the operator to access and operate the locking mechanism from the outside without needing to disassemble the device or reach into internal spaces, significantly improving ease of repair while maintaining reliable locking through the pin-groove engagement.
Solution Approach 2:
The lever acts as an intermediary between the operator's hand and the locking pin. By providing a long external arm, the lever transmits force from the operator to the pin with mechanical advantage, enabling easy actuation of the reliable internal pin-groove locking mechanism without direct access to the pin itself.
3Manufacturing precision
If a threaded hole and locking screw mechanism is used, then the manufacturing precision can be maintained, but the device complexity increases due to additional components
Solution Approach 1:
The patent merges multiple functions into the spring-loaded pin system: the pin provides both the locking function (by engaging the radial groove) and the positioning function (by being guided through the transverse hole). The spring combines the locking force provision and the automatic resetting functions. This consolidation reduces the number of separate components compared to a screw, washer, and nut assembly, simplifying the device while maintaining precision.
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 tool-free locking and unlocking of shaft connections, facilitating access and repair regardless of shaft position, reducing the need for extensive disassembly and improving maintenance efficiency.
Implementation Method 1
a spring return member (4) suitable for expelling the locking pin (3) towards the locked position
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention relates to a device (1) for connecting an end of a first shaft to an end of a second shaft, the end of the first shaft having a radial groove, the device comprising: -a body (2) having a bore (21) into which the end of the first shaft can be introduced, -a locking pin (3) mounted so as to be movable with respect to the body (2) between a locked position, in which the pin (3) projects into the bore (21) such that, when the end of the first shaft is received inside the bore (21), the locking pin (3) is engaged in the radial groove in the end of the first shaft in order to prevent the end of the first shaft from being removed from the bore (21), and an unlocked position, in which the locking pin (3) is disengaged from the radial groove in the end of the first shaft so as to allow the end of the first shaft to be introduced into the bore (21) or to allow the end of the first shaft to be removed from the bore (21), and -an elastic return member (4) for urging the locking pin (3) into the locked position.