Unité

Micromechanical and Horological Design Laboratory

Laboratoire

Publications associées (21)

Pivot, process for manufacturing such a pivot, oscillator comprising such a pivot, watch movement and timepiece comprising such an oscillator

Simon Nessim Henein, Loïc Benoît Tissot-Daguette

The present invention concerns a pivot comprising two assemblies, namely a central assembly (401) and a peripheral assembly (400). These two assemblies are mobile in rotation relative to each other around an axis of rotation (A). The pivot is characterized ...

2024

Shaking force balancing of a 2-DOF isotropic horological oscillator

Simon Nessim Henein, Etienne Frédéric Gabriel Thalmann, Hubert Pierre-Marie Benoît Schneegans

Despite centuries of research and significant advances, the escapement mechanism used to count and maintain oscillations of mechanical time bases remains a complex mechanism and a major source of energy losses. We showed in previous work that, instead of t ...

2021

Optical measurement method for mechanical time base characterization

Simon Nessim Henein, Etienne Frédéric Gabriel Thalmann

The recent adoption of silicon components by the mechanical watch industry has triggered the search for new time bases to advantageously replace the traditional balance and hairspring oscillator. In particular, flexure-based oscillators manufactured in sil ...

euspen2021

Flexure Pivot Oscillators for Mechanical Watches

Etienne Frédéric Gabriel Thalmann

It appears that the concerted efforts of the watchmaking industry are leading towards a limit in mechanical watch accuracy. The general consensus in horology is that the time base's quality factor, a dimensionless number that characterizes the oscillator d ...

EPFL2020

Flexure Pivot Oscillator With Intrinsically Tuned Isochronism

Simon Nessim Henein, Ilan Vardi, Etienne Frédéric Gabriel Thalmann, Mohammad Hussein Kahrobaiyan

The most important property for accurate mechanical time bases is isochronism: the independence of period from oscillation amplitude. This paper develops a new concept in isochronism adjustment for flexure-based watch oscillators. Flexure pivot oscillators ...

2020

Mechanical oscillator with tunable isochronism defect

Simon Nessim Henein, Mohammad Hussein Kahrobaiyan, Mohamed Gamal Abdelrahman Ahmed Zanaty

Mechanical oscillator (1) for a timepiece comprising an inertial mass (3) arranged to oscillate about a neutral position under the effect of a restoring force provided by at least one elastic element (5),characterised in that said mechanical oscillator (1) ...

2020

Crank arrangement for driving a mechanical oscillator

Simon Nessim Henein, Billy Nussbaumer, Romain Roger Henri Gillet

Crank arrangement (1) for driving a pin-driven two degrees? of freedom mechanical oscillator (5), comprising:- a crank element (7) arranged to be rotationally driven about an axis of rotation (19) by means of a mechanical source of energy (M),- a crank slo ...

2020

Design of a Flexure Based Low Frequency Foucault Pendulum

Simon Nessim Henein, Ilan Vardi, Patrick Robert Flückiger

The Foucault pendulum is a well-known mechanism used to demonstrate the rotation of the Earth. It consists in a pendulum launched on linear orbits and, following Mach’s Principle, this line of oscillation will remain fixed with respect to absolute space bu ...

2020

Sensor system

Simon Nessim Henein, Charles Baur, Hubert Pierre-Marie Benoît Schneegans, Thomas Jean Julien Fussinger, Lisa Anaïs Jeanne Bonnefoy

Sensor system (1) comprising a frame (306) supporting a force-sensing tip (310) arranged to generate a signal based upon a force applied by said force-sensing tip (310) to a material to be tested,characterised in that said system (1) further comprises:- an ...

2020

Foucault pendulum properties of spherical oscillators

Simon Nessim Henein, Ilan Vardi, Patrick Robert Flückiger

In 1851 Léon Foucault created a sensation with his pendulum providing a direct demonstration of the turning of the Earth. This simple device consists of a pendulum which is launched in a purely planar orbit. Following Mach's principle of inertia, the mass ...

euspen2020

Two degree of freedom oscillator system

Simon Nessim Henein, Mohammad Hussein Kahrobaiyan, Billy Nussbaumer, Arnaud André Emmanuel Maurel

Oscillator system (1) comprising:- a substantially planar frame (3);- a first sub-oscillator (5), a second sub-oscillator (7), a third sub-oscillator (9), and a fourth sub-oscillator (11), each sub-oscillator (5, 7, 9, 11) comprising a substantially rigid ...

2020

Conceptual design of a rotational mechanical time base with varying inertia

Etienne Frédéric Gabriel Thalmann

Flexure pivot oscillators have the potential to advantageously replace the traditional balance wheel-spiral spring oscillator used in mechanical watches due to their significantly lower friction. However, they have inherent nonlinear elastic properties tha ...

2019

Horological oscillator

Simon Nessim Henein, Ilan Vardi, Etienne Frédéric Gabriel Thalmann, Mohammad Hussein Kahrobaiyan, Billy Nussbaumer

Horological oscillator comprising: - a first inertial body (141; 151; 1305; 1405; 1505; 301; 311; 314; 41; 51; 507; 529; 544; 541; 901; 903) arranged to rotate with respect to a first axis; - a second inertial body (143; 153; 1306; 1406; 1506; 302; 313; 31 ...

2019

Theory and design of spherical oscillator mechanisms

Ilan Vardi, Roland Andreas Bitterli, Mohammad Hussein Kahrobaiyan, Lennart Rubbert, Billy Nussbaumer, Nicolas Ferrier

In previous work, we showed that two degree of freedom oscillators can be advantageously applied to horological time bases since they can be used to eliminate the escapement mechanism. We subsequently examined planar two degree of freedom oscillators based ...

2018

Programmable Multistable Mechanisms: Design, modeling, characterization and applications

Mohamed Gamal Abdelrahman Ahmed Zanaty

Multistable Mechanisms are mechanical devices having more than one stable state. Since these mechanisms can maintain different deformations with zero force, they are advantageous for low power environments such as wristwatches and medical devices. In this ...

EPFL2018

Two degree of freedom mechanical oscillator

Simon Nessim Henein, Ilan Vardi, Mohammad Hussein Kahrobaiyan

Mechanical oscillator (10) comprising an inertial body (101) joined to a support (100) by means of an elastic system (102, 103, 104, 105, 106, 107) arranged to provide the inertial body (101) with substantially no degrees of freedom in translation and with ...

2018

Mechanical oscillator

Simon Nessim Henein, Ilan Vardi, Mohammad Hussein Kahrobaiyan

wherein k1, k3, k5 . . . are constants and θ is an angle of inclination of said third axis (x, P) of said inertial body with respect to a direction of said third axis (xr) when said inertial body is in said resting position. ...

2018

Flexure-Pivot Oscillator Restoring Torque Nonlinearity and Isochronism Defect

Etienne Frédéric Gabriel Thalmann, Mohammad Hussein Kahrobaiyan

Flexure pivot based oscillators can advantageously replace the hairspring and balance wheel, the time base used in mechanical watches, by drastically reducing friction. However, flexure pivots have drawbacks including gravity sensitivity and restoring torq ...

AMER SOC MECHANICAL ENGINEERS2018

General 2 degree of freedom isotropic harmonic oscillator and associated time base without escapement or with simplified escapement

Ilan Vardi, Lennart Rubbert

The mechanical isotropic harmonic oscillator comprises at least a two degrees of freedom linkage supporting an orbiting mass with respect to a fixed base with springs having isotropic and linear restoring force properties wherein the mass has a tilting mot ...

2015

Xy isotropic harmonic oscillator and associated time base without escapement or with simplified escapement

Ilan Vardi, Lennart Rubbert

The mechanical isotropic harmonic oscillator comprises at least a two degree of freedom linkage supporting an orbiting mass with respect to a fixed base with springs having isotropic and linear restoring force properties. The oscillator may be used in a ti ...

2015

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