Chronograph Reset Hammer Ball-and-Socket Design

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Solution Overview

Problem

Existing chronograph movement hammers face challenges in precision and bulkiness, particularly in fine watchmaking, where the need for precise adjustment and reduced size is critical due to the bulk of existing structures around bearing planes.

Innovation Solution

A reset hammer with a ball-and-socket type connection between its parts, utilizing a disc-shaped protrusion and complementary clearance, allowing pivoting and retention without additional means, thereby simplifying the structure and improving reliability and resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional connection means (tongues with reentrant rims or superimposed parts) are used to link hammer parts, then the hammer can retain the lever in contact with the body, but the hammer size increases significantly around the bearing planes

Engineering Contradiction:
Improveretention of lever contact with hammer bodyVSAvoidhammer size around bearing planes
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent applies spheroidality by using a spherical protrusion on the lever that fits into a corresponding spherical clearance in the hammer body. This ball-and-socket joint provides reliable retention of the lever in contact with the body while maintaining a compact structure, avoiding the bulkiness of traditional tongue-with-reentrant-rim connections.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Reliability

If additional retention means are added to prevent lever movement, then the lever can be securely retained, but the device complexity increases

Engineering Contradiction:
Improvesecure retention of leverVSAvoidnumber of connection means
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The ball-and-socket joint serves multiple functions simultaneously: it retains the lever in contact with the hammer body, allows limited pivoting movement for resetting the chronograph cores, and provides structural support. This multi-functionality eliminates the need for separate retention means, reducing device complexity while maintaining secure retention.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of manufacture

If the hammer structure is simplified, then manufacturing and assembly are easier, but precision in bearing surface arrangement may be compromised

Engineering Contradiction:
Improvesimplicity of hammer structureVSAvoidprecision of bearing surface arrangement
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The spherical protrusion and clearance design inherently guides the lever into proper alignment with the hammer body through self-centering action. This geometric constraint ensures precise bearing surface arrangement without requiring complex adjustment mechanisms, thereby maintaining manufacturing precision while simplifying the overall structure.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP1960848B1Timepiece hammer
Publication Date: 2012.06.13 COMPLITIME SA
  • EP1960848B1 patent drawingFigure 1
  • EP1960848B1 patent drawingFigure 2

AI summary

The invention relates to a clockwork movement hammer (1) which is used for interacting with heart-shaped cams (20, 21) provided with corresponding axes of rotation (29, 30) which are positioned remotely to each other. More precisely, said hearts (20, 21) are connected to a chronograph timer, whereas the hammer belongs to the resetting mechanism of the chronograph timers. The inventive hammer (1) comprises at least one first part (5) movably mounted on the clockwork bottom plate (2) and one second part (17) bearing supporting surfaces (18, 19) which can be bring into contact with said hearts (20, 21). The two parts (5, 17) of the hammer (1) are connected to each other by at least one swivel-type connection (14, 24) for making it possible to adjust the corresponding positions of the supporting surfaces (18, 19) while a resetting process. Due to particular characteristics thereof, the structural design of the hammer (1) is simple and small-sized.