Watch Crown Orientation Mechanism Using Friction Surfaces
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Solution Overview
Problem
Existing methods for orienting screw-down crowns with logos or patterns on watch cases are inadequate, as they either require unconventional crown structures, are not robust, or result in increased size and complexity, making them unsuitable for luxury and high-quality products.
Innovation Solution
A compact orientation adjustment mechanism using flat friction surfaces between a central barrel and a cover, secured by a return means such as a flat spring or shape memory alloy, allowing adjustment only during assembly or maintenance, preventing accidental reorientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a substrate is used that can be oriented with respect to the head of the crown and separated in rotation when pressure is exerted, then the crown can be oriented in a determined position, but the structure becomes unconventional and less robust against shocks
Solution Approach 1:
The crown is divided into two main parts: a head and a cover that can rotate relative to each other. The logo is integrated into the cover, which can be independently oriented. This segmentation allows the logo to be positioned precisely while maintaining a robust monolithic structure for both the head and cover themselves, resolving the contradiction between orientation precision and structural robustness.
Solution Approach 2:
The orientation adjustment mechanism is pre-configured during manufacturing with indexing elements and friction surfaces that guide the cover to specific angular positions. This preliminary setup ensures that when the user adjusts the crown, the logo automatically aligns with predetermined orientations, achieving precise orientation without requiring an fragile or unconventional structure.
2Manufacturing precision
If shape memory alloy ring is used to adjust crown orientation by deformation, then the crown can be oriented in a determined position, but the device size increases and manufacturing becomes difficult and expensive
Solution Approach 1:
The invention extracts the orientation adjustment function from complex materials like shape memory alloys and implements it through simple mechanical elements: friction surfaces, indexing protrusions, and elastic retention. This extraction reduces the device to its essential mechanical components, eliminating the need for expensive and bulky shape memory alloy rings while maintaining precise orientation capability.
Solution Approach 2:
The orientation mechanism uses inexpensive, easily manufactured components such as friction surfaces and indexing elements that can be produced through standard machining processes. These simple mechanical elements replace costly shape memory alloys, making the device more economical and easier to manufacture while achieving the same orientation precision.
3Reliability
If frustoconical surfaces with elastic element are used to secure crown, then the crown can be adjusted angularly, but the surfaces must extend over very large area to guarantee retention
Solution Approach 1:
The invention replaces frustoconical surfaces with flat friction surfaces between the cover and head. The indexing protrusions engage with corresponding recesses to provide mechanical retention. This flat surface approach reduces the contact area needed compared to extended frustoconical surfaces, decreasing the crown volume while maintaining reliable retention through the combination of friction and positive indexing.
Solution Approach 2:
The indexing protrusions and recesses act as intermediary elements that provide mechanical retention and angular positioning. These discrete indexing features work in conjunction with the friction surfaces to secure the cover to the head, achieving reliable retention with smaller contact areas than frustoconical surfaces would require.
4Ease of manufacture
If conventional mounting methods are used for crowns with logos, then the assembly process is simple, but the logo orientation cannot be determined with respect to the case
Solution Approach 1:
The cover is pre-oriented relative to the head during manufacturing, with the logo positioned at a specific angular offset. Indexing elements are pre-configured to guide the cover to predetermined orientations when screwed onto the case. This preliminary setup allows the logo to automatically align with case inscriptions or design features, achieving precise orientation without complicating the assembly process.
Solution Approach 2:
The indexing mechanism between the cover and head, and between the crown and case, provides self-aligning functionality. When the crown is screwed onto the case, the indexing elements automatically guide the cover to the correct angular position, ensuring the logo is properly oriented relative to case features. This self-service orientation eliminates the need for complex alignment procedures while maintaining manufacturing simplicity.
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
The solution provides a robust, compact, and aesthetically pleasing method to adjust the orientation of the logo or pattern on screw-down crowns, ensuring reliability and preventing unintended changes, while maintaining the crown's sealing and operational integrity.
Implementation Method 1
a first friction surface (231) arranged on a central barrel (2) and a second friction surface (31) arranged on a cover (11), the friction surfaces being in mutual contact
Implementation Method 2
a return means (4) distinct from those associated with the extension of the piston, the return means tending to make the cover and the central barrel integral in rotation
Implementation Method 3
the return means consist of a flat spring (4), with a thickness e1 of at most 0.2mm
Implementation Method 4
a return means (4) distinct from those associated with the extension of the piston, the return means tending to make the cover and the central barrel integral in rotation
Data Source
Figure 1~2
Figure 3~4
AI summary
An orientable screwed element comprising a cover (11) and a device for adjusting the angular orientation of the cover (11) in relation to a watch middle, characterised in that the device for adjusting the angular orientation of the cover (11) comprises: a first part (23) provided with a first flat friction surface (231); a second part (3) solidly connected to the cover (11), provided with a second flat friction surface (31); and return means that rotatably fixes the cover (11) to the first part. The cover (11) and the first part (23) can move axially in relation to one another between: a first position (P1), in which the first flat friction surface (231) and the second flat friction surface (31) are pressed against one another by the return means, such that the cover (11) is rotatably connected to the first part (23); and a second position (P2), in which the first flat friction surface (231) and the second flat friction surface (31) are no longer in contact, the cover (11) then being free to rotate about the axis of rotation of the orientable screwed element.