Interchangeable Watch Crown Locking Mechanism With Low-Play Fit
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Solution Overview
Problem
Existing timepiece and jewelry designs face issues with unreliable and aesthetically unappealing crown mechanisms, significant play between moving parts, and the inability to easily change elements like crowns or cabochons without replacing the entire mechanism.
Innovation Solution
A removable crown mechanism with a locking device featuring elastic return elements, locking balls, and a compact locking mechanism that ensures secure mounting and easy interchangeability, preventing accidental disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a removable crown mechanism is implemented, then the ease of changing the crown is improved, but the reliability of the connection between the crown and control stem deteriorates
Solution Approach 1:
The locking ball is nested within a cavity in the control stem, and the crown contains an inner ring with a receptacle that receives the locking ball. This nested arrangement ensures the locking ball is securely contained within the assembly while enabling reliable locking when the crown is properly positioned on the control stem.
Solution Approach 2:
The elastic return element pre-positions the locking ball within the control stem cavity before the crown is attached. This preliminary positioning ensures that when the crown is mounted, the locking ball is already in the correct position to engage with the receptacle, providing immediate and reliable locking without requiring additional adjustment steps.
2Reliability
If a locking mechanism is added to secure the crown, then the reliability of the connection is improved, but the device complexity increases
Solution Approach 1:
The elastic return element automatically returns the locking ball to its locked position within the control stem cavity after the crown is detached or during normal operation. This self-service mechanism eliminates the need for manual resetting or complex control systems, maintaining reliability while minimizing complexity.
Solution Approach 2:
The locking mechanism is merged with the crown attachment structure itself. The inner ring of the crown incorporates the receptacle for the locking ball, and the control stem cavity houses the locking ball and elastic return element. This integration combines the locking function with the existing crown and stem structures, avoiding the need for separate, complex locking components.
3Shape
If the locking mechanism is made compact to conceal within the crown, then the aesthetic appeal is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The locking ball and elastic return element are nested within the control stem cavity, which is itself part of the crown assembly. This nested configuration keeps all locking components contained within the existing crown volume without requiring additional external space, maintaining aesthetic appeal while accommodating the necessary precision components.
Solution Approach 2:
The locking mechanism is segmented into distinct functional components: the control stem cavity houses the locking ball and elastic return element, while the crown's inner ring contains the receptacle. This segmentation allows each component to be manufactured and assembled separately with controlled precision requirements, then integrated into the final compact locking assembly.
4Reliability
If play between the crown and control stem is reduced to improve perceived quality, then the reliability is improved, but the ease of detaching the crown deteriorates
Solution Approach 1:
The locking ball provides localized precision engagement at specific points (the receptacle position) while allowing minimal play in other directions. This localized quality control ensures the crown feels securely locked and stable during normal wear, yet maintains the ability to be easily detached when intentional force is applied to overcome the locking mechanism.
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
Facilitates easy and reliable exchange of crown elements while maintaining assembly quality and reliability, ensuring secure attachment and preventing accidental disassembly.
Implementation Method 1
at least one elastic return element is mounted between the cap and the outer ring so as to axially stress the outer ring towards its locked position
Data Source
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AI summary
The present invention relates to a control device (20) for a watch part (10) comprising a control rod (22) which is equipped with a removable crown (24), the control device (20) comprising a locking device (26) which, in the locked position, secures the crown (24) with the control rod (22) and, in the unlocked position, detaches the crown (24) from the control rod (22), characterized in that the crown (24) comprises a cap (28) and a main tubular body (30) which is fixed to the cap (28), in that the locking device (26) comprises an outer ring (36) which, in the locked position, axially locks the crown (24) on the control rod (22) and, in the unlocked position, releases the crown (24) from the control rod (22).