Watch Control Stem Device with Sliding Pinion for Compact Crown Placement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional watch stem devices with a single piece or two aligned stems require additional space and components to accommodate complications, leading to an inconvenient and unattractive placement of the crown, and suffer from inaccuracies due to axial play in the mobile frame connecting the stems.
Innovation Solution
A control stem device with a first stem that axially moves between winding and time-setting positions, using a sliding pinion mechanism to switch between functions, eliminating the need for a mobile frame and allowing for a compact, conventional pull-out mechanism with defined positions and easy assembly/disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a single piece or two aligned stems are used in conventional devices, then the structure is simpler, but the crown placement becomes inconvenient and unattractive when complications are present
Solution Approach 1:
The stem is divided into two separate stems (first stem and second stem) that are shifted in height relative to each other. The first stem carries the crown at the conventional position, while the second stem extends into the movement to engage with the winding and time-setting mechanisms. This segmentation allows the crown to remain accessible while the functional stem reaches the necessary depth.
Solution Approach 2:
A transmission device acts as an intermediary between the first stem (with crown) and the second stem (engaging mechanisms). This transmission device transfers rotational motion from the first stem to the second stem, allowing the crown to be positioned conveniently while still driving the internal mechanisms that require deeper access.
2Manufacturing precision
If a mobile frame containing the gear is used to connect the two stems, then the stems can be secured in translation, but the space requirement increases and axial play causes inaccuracies
Solution Approach 1:
The mobile frame containing the gear is completely removed from the design. Instead, the invention uses a direct transmission device that connects the two stems without requiring a mobile supporting structure. This extraction eliminates the source of axial play and simplifies the overall device architecture.
Solution Approach 2:
The transmission device is designed to directly connect the first stem and second stem through their respective mounting points, merging the functional connection without requiring a separate mobile frame structure. This direct connection eliminates the intermediate mobile frame that caused axial play and increased space requirements.
3Ease of operation
If the second stem follows the first when the crown is pulled out, then the pull-out function works, but additional space is required for the mobile frame and gear
Solution Approach 1:
The mobile frame and gear mechanism are completely removed from the design. The pull-out function is achieved through a different mechanism that does not require additional space for a mobile supporting structure, thereby reducing the overall volume of the device while maintaining operational functionality.
Data Source
AI summary
The control stem device for a watch includes a first stem (1) rotating about its longitudinal axis and provided with means (32) for securing it to a manual control crown on the exterior of the watch, and a second stem (2), substantially parallel and shifted in relation to said first stem and secured to an axially mobile sliding pinion (8) for selectively driving in rotation a mechanism for a first function (20) and a mechanism for a second function (242), the first and second stems being connected in rotation by a transmission device (5). The first stem is mounted to be axially mobile at least between an operating position associated with said first function and an operating position associated with said second function, so as to activate, by sliding between said positions, a pull-out mechanism (6) which cooperates with said sliding pinion (8) to make said pinion pass from one axial position to another, said sliding pinion (8) being meshed with the mechanism for the first function in one of its positions and with the mechanism for the second function in the other position. The first stem (1) slides in the first pinion (35) of the gear and can be removed. This device allows the control crown to be placed half way up the watchcase, in particular in the case of a watch with complications having a very thick movement.