Watch Date Display Mechanism with Segmented Digit Control
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Solution Overview
Problem
Conventional date display mechanisms for timepieces, particularly portable wristwatches, face limitations due to small angular sectors for date indications, requiring numerous parts and experiencing reliability issues with large angular steps, leading to cluttered designs and reduced readability.
Innovation Solution
A date display mechanism with two mobiles, each having 10 display segments, allowing for balanced and larger character sizes by equally distributing indications, and incorporating functional parts for indexing sequences, reducing the number of parts and enhancing reliability through integrated control mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional annular date disc with 31 sectors is used, then the date can be displayed, but the angular sector for each date indication is small (less than 12 degrees), limiting the maximum size of displayed numbers
Solution Approach 1:
The date display is segmented into two separate mobiles: one for units digit (10 segments) and one for tens digit (10 segments). Each mobile independently displays one digit, allowing larger character sizes while maintaining complete date information. This segmentation resolves the contradiction by distributing the 31-date information across two mobiles with larger individual segments.
Solution Approach 2:
The invention transitions from a single-dimensional 31-sector annular disc to a two-dimensional combination of two separate mobiles (units and tens), each with 10 segments. This dimensional change allows each segment to be larger while still displaying the complete date through combination of the two mobiles.
2Measurement precision
If two distinct mobiles are used for big date display, then larger character size is achieved, but the number of parts increases and device complexity increases
Solution Approach 1:
The invention merges the control mechanisms of the two mobiles by using a single control device that indexes both the units mobile and tens mobile. The gear segments and indexing mechanisms are combined into one integrated control system, reducing the number of separate parts compared to having independent control mechanisms for each mobile.
Solution Approach 2:
The control device performs multiple functions: it indexes both mobiles, provides gear segments for both units and tens mobiles, and handles the coordination between the two mobiles through a single mechanism. This multi-functionality reduces overall device complexity despite using two mobiles for display.
3Device complexity
If the tens disc uses only 4 digits (0-3) distributed over 90-degree sectors, then the structure is simple, but the angular step is large and reliability of indexing is reduced
Solution Approach 1:
The invention applies different segment configurations to different mobiles: the units mobile has 10 segments for digits 0-9, while the tens mobile has 10 segments for digits 0-3 (with some segments showing multiple tens values). This local differentiation optimizes each mobile for its specific function while maintaining overall system reliability through smaller, more numerous segments.
Solution Approach 2:
The invention changes the parameter of segment count from 4 segments (conventional) to 10 segments (invention), reducing the angular step from 90 degrees to 36 degrees. This parameter change significantly improves indexing reliability while maintaining structural simplicity through the regular 10-segment configuration.
4Measurement precision
If display indications are not regularly distributed, then the design may be simpler, but the balance and size of displayed characters is reduced
Solution Approach 1:
The invention uses symmetric regular distribution of 10 segments around each mobile (36-degree intervals), creating visual balance and uniform character sizing. The asymmetric element comes from the different functions of the two mobiles (units vs tens) and their different indication patterns, which together create the complete date display while maintaining individual mobile symmetry.
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 2A~2D
AI summary
Control device for displaying a large date type date for a watch movement comprising a first mobile (M1) for displaying the units (u) and a second mobile (M2) for displaying the tens (d), the first and second mobile (M1,M2) being arranged to display the date values by combination of indications carried by the first mobile (M1) the second mobile (M2), characterized in that the first mobile (M1) carries a first series of indications (I1) of consecutive units digits (U) on ten first display segments (S10-S19) regularly distributed on angular sectors of the first mobile (M1), and that the second mobile (M2) carries a second series of indications (I2) for displaying the tens digits (d) of the date on ten second display segments (S20-S29) regularly distributed on angular sectors of the second mobile (M2).