Horological Display Mechanism With Self-Locking Gears and Ball Bearings

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Solution Overview

Problem

Existing watchmaking mechanisms for displaying two-digit horological values, such as date, face challenges in maximizing digit size due to high inertia of discs, which requires powerful jumpers and increased torque, complicating assembly and readability.

Innovation Solution

A mechanism featuring self-locking gears and ball bearings allows for large-sized units and tens discs with reduced inertia, eliminating the need for jumpers and minimizing torque, enabling larger digit display while simplifying assembly and maintaining synchronization during manual corrections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If solid discs are used for units and tens display, then the digits can be displayed, but the inertia of the discs becomes too high requiring powerful jumpers and increased torque

Engineering Contradiction:
Improvesynchronization reliabilityVSAvoidtorque requirement
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent divides the display function into two separate wheels: a units wheel with digits 0-9 and a tens wheel with digits 0-3. Each wheel is driven independently by its own programming wheel, allowing smaller, lower-inertia discs while maintaining complete date display capability through the combination of both wheels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces programming wheels that dynamically control the rotation of the units and tens wheels. The programming wheels engage with the units/tens wheels at specific positions to advance them by one step, enabling precise control of the display without requiring high-inertia discs or powerful jumpers.

Inventive Principle:
Principle #15Dynamics

2Force

If annular discs are used instead of solid discs, then the inertia is reduced, but the mounting and pivoting during movement becomes complicated

Engineering Contradiction:
Improvetorque requirementVSAvoidmounting complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent separates the units display and tens display into independent wheels, each with its own programming wheel and bearing arrangement. This segmentation allows each component to be optimized independently, simplifying the mounting and pivoting mechanisms while reducing overall inertia.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces programming wheels as intermediary components between the drive wheel and the units/tens wheels. These programming wheels facilitate the transmission of motion and positioning, simplifying the overall mechanism by providing a clear intermediate step for engagement and disengagement.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Area of moving object

If the discs are made larger to maximize digit size, then the display area increases, but the inertia increases requiring more torque

Engineering Contradiction:
Improvedigit display areaVSAvoidtorque requirement
Core Design Contradiction:
Area of moving objectVSForce

Solution Approach 1:

The patent divides the date display into two separate wheels (units and tens), each capable of being smaller in diameter. By segmenting the display function, each wheel can be optimized for minimal size while still providing complete date information, thereby reducing inertia and torque requirements compared to a single large disc.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-disc radial arrangement to a multi-wheel system where units and tens wheels can be positioned at different radial distances from the center. This dimensional arrangement allows larger digit display area without increasing the inertia of individual wheels, as each wheel operates independently at its optimal size and position.

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

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 enables the display of larger digits with reduced energy consumption and improved assembly efficiency, maximizing surface area for date or other information display without compromising synchronization.

Implementation Method 1

The tens wheel is pivoted about the said first axis of rotation by means of a tens ball bearing and the said units wheel is pivoted about the said first axis of rotation by means of a units ball bearing

Methodology Applied
Scientific EffectBall Bearing: Ball Bearing

Implementation Method 2

said units programming wheel is arranged to cooperate with said units mobile through a first self-locking gear, and said tens programming wheel is arranged to cooperate with said tens mobile through a second self-locking gear

Methodology Applied
Scientific EffectSelf-locking gear mechanism: Gear

Data Source

PatentEP3764171B1Mechanism for displaying a horological value
Publication Date: 2022.04.06 MFG & FAB DE MONTRES & DE CHRONOMETRES ULYSSE NARDIN LE LOCLE SA
  • EP3764171B1 patent drawingFigure 1
  • EP3764171B1 patent drawingFigure 2
  • EP3764171B1 patent drawingFigure 3

AI summary

A mechanism for displaying a clock value (1) consisting of a units digit and at least one tens digit when the latter is greater than zero, said mechanism comprising: - a first axis of rotation (A1) around which are pivoted: a) a units wheel (61, 71) comprising a units disc (71) bearing digits corresponding to said units; b) a tens wheel (51, 81) comprising a tens disc (81) bearing digits corresponding to said tens; - a drive wheel (13) arranged to be driven in steps of 1/n turns under the control of an input wheel (21) intended to be driven by a basic movement, n being a non-zero natural integer; - a units programming wheel (33) arranged to be driven by said drive wheel (13) and to rotate said units wheel (61, 71);- a tens programming wheel (43), arranged to be driven by said control wheel (13) and to rotate said tens wheel (51, 81). According to the invention: - said units programming wheel (33) is arranged to cooperate with said units wheel (61, 71) by means of a first self-locking gear (64, 61); - said tens programming wheel (43) is arranged to cooperate with said tens wheel (51, 81) by means of a second self-locking gear (55, 51); in which said tens wheel (51, 81) is pivoted about said first axis of rotation (A1) by means of a tens ball bearing (R1) and said units wheel (61, 71) is pivoted about said first axis of rotation (A1) by means of a units ball bearing (R2); and in which a first (R1;R2) among said tens ball bearing (R1) and said units ball bearing (R2) is mounted on a support (3) intended to be fixed to a frame element, a second (R2; R1) among said tens ball bearing (R1) and said units ball bearing (R2) being mounted between said tens wheel (51, 81) and said units wheel (61, 71).;