Jumper Spring Guide Mechanism for Watch Indexing

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Solution Overview

Problem

Existing watch mechanisms with a star and jumper spring biased by a spring face difficulties in assembly due to high torque requirements, leading to potential misalignment or disengagement of the jumper spring, especially when the force exceeds a certain threshold, and the presence of additional components like circular rims increases complexity and thickness, affecting indexing accuracy.

Innovation Solution

The mechanism employs rectilinear and parallel slides as guide means to allow the rigid element to move in translation parallel to a determined direction, with a jumper spring comprising elastic arms that surround the star and are secured by stops, facilitating tension and assembly, and reducing stress on components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the spring force is increased to ensure reliable engagement of the jumper with the star, then the reliability of the coupling mechanism is improved, but the jumper's pivot or spring becomes misaligned or dislodged during assembly

Engineering Contradiction:
Improvereliability of coupling mechanismVSAvoidease of assembly
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent transitions from a pivot-based rotational movement to a slide-based linear movement. The rigid element moves along a linear path defined by the slide rather than rotating around a pivot point. This dimensional change from rotational to linear motion eliminates the alignment and disengagement problems associated with pivot-based mechanisms while maintaining reliable engagement through the slide constraint.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the movement parameter from angular (rotational) to linear (translational). By replacing the pivot mechanism with a slide, the system transforms the degree of freedom from rotational to linear, allowing the rigid element to move strictly along the slide's defined path. This parameter change prevents misalignment and dislodgement during assembly while ensuring reliable engagement under spring force.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If additional components like circular rims are added to guide the jump spring, then the stability and positioning accuracy are improved, but the device complexity and thickness increase

Engineering Contradiction:
Improveindexing accuracyVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the circular rim component from the mechanism. Instead of using a rim to guide the jump spring, the design relies on the slide to constrain the rigid element's movement. This removal of the rim simplifies the overall device structure, reduces thickness, and decreases component count while maintaining positioning accuracy through the slide's linear guidance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The slide serves multiple functions: it guides the rigid element's movement, defines the linear path, constrains lateral displacement, and eliminates the need for separate guiding components like circular rims. This multi-functionality reduces device complexity while maintaining the necessary positioning and stability.

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

3Ease of operation

If the jump spring is allowed to pivot during operation, then the ease of operation is improved, but the indexing precision deteriorates

Engineering Contradiction:
Improveease of operationVSAvoidindexing precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces rotational pivoting with linear sliding movement. The rigid element is constrained to move only along the slide's linear path rather than rotating around a pivot. This dimensional change eliminates unwanted rotational motion while maintaining operational smoothness through the linear guide, thereby preserving indexing precision.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the movement parameter from angular to linear. By constraining the rigid element to translate along the slide rather than rotate, the system eliminates the pivoting degree of freedom. This parameter change ensures precise indexing by preventing rotational deviation while maintaining ease of operation through the smooth linear guidance provided by the slide.

Inventive Principle:
Principle #35Parameter changes

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

This configuration improves angular accuracy of indexing and simplifies assembly by preventing pivoting and ensuring the rigid element is biased against the star, maintaining engagement without excessive stress, thus overcoming the assembly challenges and indexing inaccuracies of prior designs.

Implementation Method 1

the jump spring comprising a rigid element having a prominence arranged to cooperate with the star, and at least one elastic portion which is arranged to at least partially surround the star

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the support comprising a support structure arranged to tension the jump spring by retaining said at least one elastic portion so that the rigid element is returned against the star

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3650953B1Timepiece mechanism comprising a star and a jumper spring
Publication Date: 2021.12.15 PATEK PHILIPPE SA
  • EP3650953B1 patent drawingFigure 1~2
  • EP3650953B1 patent drawingFigure 3
  • EP3650953B1 patent drawingFigure 4

AI summary

The clockwork mechanism comprises a star (17) and a jump spring (31) having a rigid element (33) with a protrusion (35) arranged to cooperate with the star, and at least one elastic arm (37a, 37b) attached to the rigid element at one end and arranged to at least partially surround the star (17), the jump spring (31) being mounted on a support (15), and the device further comprising guiding means (39, 40, 41a, 42a, 41b, 42b) arranged to allow the rigid element (33) to move in translation parallel to a predetermined direction relative to the support when the rigid element is lifted by one of the teeth of the star and then falls back between two teeth thereof, the support (15) further having at least one stop (45, 46) arranged to constrain the spring-loaded by retaining the distal end of said at least one elastic arm (37a, 37b),so that the rigid element (33) is pulled against the star (17).