Bayonet Display Module Assembly for Watch Movements

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Solution Overview

Problem

The high manufacturing and assembly costs of timepiece movements with holding plates, due to expensive stamping tools and complex assembly processes, are a significant challenge in the horology field, particularly for calendar watches.

Innovation Solution

A bayonet assembly system is introduced, comprising a contact surface on the display member and positioning surfaces on the central bridge, allowing the display member to be axially positioned and assembled independently of a holding plate, forming a pre-assembled display module that can be easily integrated into the timepiece movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a holding plate is used to axially position the display member, then the display member is securely held, but the manufacturing cost increases due to expensive stamping tools and the assembly cost increases due to complex final assembly operations

Engineering Contradiction:

Improveaxial positioning of display memberVSAvoidmanufacturing and assembly cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts and eliminates the holding plate from the assembly by integrating its positioning function directly into the bridge structure. The bridge is modified to include positioning surfaces that directly engage with the display member, removing the need for the separate holding plate component and its associated stamping tools and assembly operations.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The positioning function previously performed by the holding plate is merged into the bridge structure. The bridge now includes integrated positioning surfaces that directly axially position the display member, combining multiple functions into a single component and eliminating the need for separate positioning mechanisms.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If a holding plate is used to position the display member, then axial positioning is achieved, but the device complexity increases due to additional components and assembly steps

Engineering Contradiction:

Improveaxial positioning of display memberVSAvoidnumber of components and assembly operations

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The holding plate component is extracted and removed from the assembly. Its positioning function is transferred to the bridge, reducing the total number of components and simplifying the assembly structure.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The positioning function is merged into the bridge structure, which now includes integrated positioning surfaces. This reduces the number of separate components and simplifies the assembly process by eliminating the holding plate and its assembly steps.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS7791983B2Timepiece movement fitted with a display module

Publication Date: 2010.09.07 ETA SA MFG HORLOGERE SUISSE

AI summary

The invention concerns a timepiece movement of the type including a fixed support (23), fitted with a display module (24) including a central bridge (26) secured to said support (22) and an annular display member (28) with an axis AA, mounted to rotate freely substantially around the bridge (26), abutting on the support (22). The display member (28) includes a contact surface (37) and the bridge (26) includes at least one positioning surface (40) cooperating with the contact surface (37) so as to position the display member (28) axially on the support (22).