Chronograph Reset Mechanism Using Embedded Spring Energy

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Solution Overview

Problem

Traditional chronograph resetting mechanisms consume significant energy due to friction connections and hammer mechanisms, leading to inefficiencies and space constraints in timepieces.

Innovation Solution

A system utilizing a flexible element, such as an on-board spring, linked between a hammer and a control rocker, stores energy when the rocker is activated, allowing the hammer to reset the chronograph to zero with minimal friction, leveraging the stored energy for resetting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If traditional friction-based linkages and heart-hammer mechanisms are used to reset chronograph counters, then the resetting function is achieved, but significant energy is consumed and torque requirements are high

Engineering Contradiction:

Improveenergy consumption during resetVSAvoidtorque required for reset

Core Design Contradiction:

Use of energy by moving objectVSEase of operation

Solution Approach 1:

The spring is pre-compressed by the control lever before the reset operation is initiated. This preliminary action stores elastic potential energy that is then released to drive the hammer, eliminating the need for high torque during the actual reset operation and significantly reducing energy consumption.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system transitions from a static friction-based linkage to a dynamic spring-driven mechanism. The spring provides a dynamic force that overcomes the inertia and friction of the reset components more efficiently than static friction linkages, reducing both energy consumption and operational torque requirements.

Inventive Principle:

Principle #15Dynamics

2Use of energy by moving object

If an additional mainspring barrel is added to provide energy for resetting, then the energy requirement is met, but space constraints are worsened

Engineering Contradiction:

Improveenergy availability for resetVSAvoidspace occupied by energy storage

Core Design Contradiction:

Use of energy by moving objectVSVolume of moving object

Solution Approach 1:

The reset mechanism integrates the energy storage function into the existing control lever and hammer assembly. The spring is embedded within the control lever structure, merging the energy storage function with the control mechanism itself, thereby eliminating the need for a separate mainspring barrel and saving significant space.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The control lever serves multiple functions: it controls the start/stop of the chronograph and simultaneously compresses the spring to store energy for the reset operation. This multi-functionality eliminates the need for dedicated energy storage components, addressing space constraints.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of operation

If a rebounding mechanism with resistance point is used, then the reset function is performed through inertia, but negative friction consumes significant energy

Engineering Contradiction:

Improvereset mechanism operationVSAvoidenergy consumption during reset

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The invention converts the harmful effect of friction into a beneficial pre-compression force. Instead of friction opposing the reset motion, the spring uses friction and resistance during the compression phase to store energy, which is then released to drive the reset operation, effectively converting the harmful friction into useful stored energy.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 system enables efficient resetting of chronograph counters with reduced energy consumption and no additional friction, addressing the inefficiencies of traditional methods while maintaining compactness.

Implementation Method 1

a flexible element, such as an on-board spring, linked between a hammer and a control rocker, stores energy when the rocker is activated

Methodology Applied

Scientific EffectElastic energy storage: Spring

Data Source

PatentEP3876042B1System for resetting a chronograph

Publication Date: 2023.12.06 MONTRES BREGUET SA

Figure 1a~1b
Figure 2
Figure 3a~3b

AI summary

The chronograph reset system (1) is equipped with a chronograph counting gear (2), which includes at least one minute counter having a minute wheel (4), and a second counter, which includes a chronograph wheel (3). The system (1) includes a hammer (6) held locked by a locking means (11) and movable from an inactive position, where the hammer (6) is locked by the locking means (11), to an active position, when the hammer (6) is unlocked, for resetting the chronograph by contacting the various wheels (3, 4).The system (1) includes a flexible element (10), such as an embedded spring, connected between a reset control means (12) and the hammer (6) used for resetting the chronograph, and is configured to store energy during a movement of the control means (12) and before the release of the hammer (6) blocked by the locking means (11) so as to be able, at the moment of release of the hammer (6), to release this stored energy and drive the hammer (6) for resetting the chronograph.