Monostable Detent Escapement with Two Rest Pallets

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing detent escapement for timepieces, as described by Georges Daniels, is difficult to build and requires precise location of components to avoid efficiency loss, uses three rest pallets leading to operational disturbances, and is bistable, differing from the desired monostable system.

Innovation Solution

A monostable detent escapement with a blocker carrying two rest pallets and a rod whose end cooperates with a plate pin, intersecting both pivot axes, and featuring means for reengaging the rest pallets in the escapement wheels, utilizing fins or a spring for proper interception and re-engagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a bistable system with three rest pallets is used, then the escapement can lock both wheels, but the system becomes complex and requires precise component location

Engineering Contradiction:
Improvelocking capabilityVSAvoidnumber of rest pallets
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts one rest pallet from the system, reducing from three rest pallets to two. This simplification is achieved by modifying the blocker geometry and rod-pin interaction to maintain stable equilibrium with fewer pallets, directly resolving the contradiction between reliability and device complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The blocker is segmented into distinct functional elements: the blocker body carrying two rest pallets, the rod for pin cooperation, and reengagement means. This segmentation allows each element to perform its specific function efficiently, reducing overall system complexity while maintaining locking capability

Inventive Principle:
Principle #1Segmentation

2Stability of the object's composition

If the rod axis intersects both pivot axes when wheels are at rest, then a monostable system is achieved, but the construction requires precise alignment

Engineering Contradiction:
Improvestable equilibriumVSAvoidaxis alignment
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The rod and pin are designed with predetermined geometric relationships that establish the correct axis intersection and monostable equilibrium position during assembly. The reengagement means are pre-configured to guide the system into the correct configuration, reducing the need for high-precision manual alignment

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The rod acts as an intermediary element that mediates between the plate pin and the blocker pivot. Its specific geometry and intersection property create a mechanical constraint that naturally guides the system into monostable equilibrium, reducing sensitivity to manufacturing variations

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If transfer rest between pallets is implemented, then wheel escape is enabled, but operational disturbances occur

Engineering Contradiction:
Improvewheel escapeVSAvoidoperational stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent converts the potential harm of transfer rest disturbances into a beneficial controlled transition mechanism. The reengagement means are designed to manage the transfer rest process, converting what would be a disturbance into a controlled operational feature that maintains overall system reliability

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

Data Source

PatentEP1983389B1Escapement comprising two escape wheels
Publication Date: 2009.11.25 ETA SA MFG HORLOGERE SUISSE
  • EP1983389B1 patent drawingFigure 1~2
  • EP1983389B1 patent drawingFigure 3~6
  • EP1983389B1 patent drawingFigure 7~10

AI summary

The escapement has escape wheels (1, 2) driven by independent gear trains, barrels. A roller carries impulse pallet stones (10, 11) that are arranged for cooperating respectively with the wheels. A brake lever (8) carries locking pallet stones (12, 13) that are arranged for cooperating respectively with the wheels. An axis of the stick intersects an axis of a pivot (3) of the roller and an axis of the pivot of the lever, when the wheels are locked on the pallet stones. The lever comprises a re-engaging unit (16) for re-engaging the pallet stones respectively in the wheels.