Timepiece Arbor Guide Configuration for Rotation Inaccuracy
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Solution Overview
Problem
In existing timepiece movements, the arbors for the hour, minute, and 24-hour hands often contact each other, leading to backlash and inaccuracy due to friction and lubricant viscosity, causing the hands to waver and appear less precise.
Innovation Solution
The timepiece movement design incorporates guides between each arbor to prevent contact and rotation synchronization, using tubular configurations and guides disposed between the arbors to suppress contact and rotation caused by lubricant viscosity, with the third guide integrated into the date indicator bridge to reduce parts count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If individual arbors are used for second hand, minute hand, and hour hand without additional guides, then the structure is simpler, but the arbors contact each other causing backlash and rotation inaccuracy
Solution Approach 1:
The patent introduces guide structures (first guide, second guide, third guide) as intermediary elements between the arbors. These guides act as mediators that prevent direct contact between the second hand arbor, minute hand arbor, and hour hand arbor, thereby eliminating the harmful interaction while maintaining structural efficiency. The guides are integrated into existing components (center pipe, main plate, date indicator bridge) rather than being separate add-on elements.
2Reliability
If lubricant is injected between arbors to reduce friction, then friction and wear are reduced, but lubricant viscosity causes unwanted rotation of slower-moving arbors when faster arbors rotate
Solution Approach 1:
The guide structures serve as physical intermediaries that block the transmission of rotational force through the lubricant. Even though lubricant remains present between the arbors for friction reduction, the guides prevent the viscous coupling from causing unwanted rotation of the minute and hour hands when the second hand arbor rotates.
Solution Approach 2:
The patent segments the rotational movement of each arbor by introducing guides that create independent rotational zones. The first guide segments the space between the second hand arbor and minute hand arbor, the second guide segments the space between the minute hand arbor and hour hand arbor, and the third guide segments the space between the hour hand arbor and 24-hour hand arbor, preventing cross-contamination of rotational movement.
3Measurement precision
If multiple guides are added to prevent arbor contact, then hand rotation accuracy is improved, but the number of parts and device complexity increases
Solution Approach 1:
The patent merges the guide functions with existing structural components of the timepiece movement. The first guide is formed as part of the center pipe, the second guide is integrated into the main plate, and the third guide is combined with the date indicator bridge. This merging approach provides the necessary guidance and isolation functions without adding separate, independent parts, thereby maintaining manufacturing efficiency and reducing assembly complexity.
Solution Approach 2:
The guide structures perform multiple functions simultaneously: they provide mechanical guidance for arbor rotation, prevent direct contact between arbors, block viscous coupling through lubricant, and are integrated into existing components that already serve other functions in the movement. This multi-functionality reduces the overall part count despite the added guidance capability.
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
This configuration effectively suppresses unwanted rotation between arbors, enhancing precision by preventing contact and lubricant-induced movement, thereby improving the accuracy and stability of the timepiece hands.
Implementation Method 1
the viscosity of the lubricant may cause the minute hand arbor to turn when the second hand arbor turns
Implementation Method 2
the viscosity of the lubricant may cause the minute hand arbor to turn when the second hand arbor turns
Data Source
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AI summary
A timepiece movement and a timepiece suppress rotation of one arbor in conjunction with rotation of another arbor. A timepiece movement includes a second hand wheel with a second hand arbor; a minute hand wheel with a minute hand arbor; an hour hand wheel with an hour hand arbor; a 24-hour hand wheel with a 24-hour hand arbor; and a first guide, a second guide, and a third guide each configured to guide an arbor to which a hand attaches. The minute hand arbor, the hour hand arbor, and the 24-hour hand arbor have a tubular configuration and are disposed coaxially to the second hand arbor. The minute hand arbor has a diameter greater than the second hand arbor, the hour hand arbor has a diameter greater than the minute hand arbor, and the 24-hour hand arbor has a diameter greater than the hour hand arbor. The first guide is disposed between the second hand arbor and the minute hand arbor, the second guide is disposed between the minute hand arbor and the hour hand arbor, and the third guide is disposed between the hour hand arbor and the 24-hour hand arbor.