Watch Crown Spring Mounting for Flat Profile and Maintenance
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Solution Overview
Problem
Existing timepiece crown systems require gluing, welding, or screwing, making maintenance difficult and limiting design flexibility, especially when the crown is recessed into a housing, and they do not accommodate ultra-flat watch designs well.
Innovation Solution
A crown system with a cap mounted integral to a control rod, secured by a spring that allows easy removal and adjustment, enabling the crown to be locked in rotation and released without additional components, and allowing for telescopic movement to accommodate varying axial displacements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the crown is glued, welded or screwed onto the stem, then the connection is secure, but maintenance becomes difficult and the crown may come apart unexpectedly
Solution Approach 1:
The crown assembly is segmented into separate components: a crown body and a stem, connected through a control rod mechanism. This segmentation allows the crown to be detached and reattached without permanent bonding, facilitating maintenance while maintaining secure connection during operation through the locking mechanism
Solution Approach 2:
The connection between crown and stem is made dynamic rather than static. The control rod can move between locked and unlocked positions, allowing the crown to be securely fixed during normal operation but easily removable when needed for maintenance, resolving the contradiction between connection security and ease of repair
2Shape
If the crown is recessed into a housing, then the watch profile is flattened, but the housing depth is limited by the movement control system
Solution Approach 1:
The solution moves the control mechanism from the axial dimension (housing depth) to the radial dimension (control rod movement). The control rod can move laterally within the housing without requiring increased housing depth, allowing the crown to be fully recessed while maintaining functional versatility
Solution Approach 2:
The control rod acts as an intermediary between the crown and the movement. It transmits rotational and translational movements from the crown to the movement without requiring direct coupling, enabling the crown to be recessed deeper than traditional designs while maintaining full functionality
3Ease of operation
If the crown is pulled outwards to control movement functions, then the crown can be indexed with respect to the caseband, but the system requires additional components and complexity
Solution Approach 1:
The indexing function and the control function are merged into a single crown operation. As the crown is pulled out and rotated, it simultaneously indexes with the caseband and controls movement functions through the control rod, eliminating the need for separate indexing mechanisms and reducing overall system complexity
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
Simplifies maintenance and design flexibility by eliminating the need for glues or welding, ensuring secure and removable connections, and allowing for an ultra-flat profile that does not interfere with the wearer's skin.
Implementation Method 1
The spring can allow limited sliding between the cap and the rod, or can alternatively be used to securely fasten these parts to each other
Data Source
Figure 1~2d
Figure 3~4
Figure 5~6
AI summary
A timepiece comprising: - a watch case (1) having a case body (3) with a passage (5) through a side wall thereof; - a movement housed within said case (1); - a control stem (7) taking place in said passage (5) and being connected to said movement, said stem (7) being arranged to be movable in rotation and in translation about its principal axis; - a crown (9) located outside said case (1) and mounted on said stem (7); in which said crown (9) and said case body (3) each include complementary locking elements (25, 17, 27, 29) arranged to interlock with each other in order to lock said crown (9) in rotation in a depressed axial position of said stem (7) and to release the rotation of the crown (9) in at least one pulled axial position of said stem (7).According to the invention, the crown (9) comprises a cap (11) mounted rotationally fixed to said rod (7), the cap (11) being fixed to said rod (7) by means of a spring (19).