Timepiece assembly with at least two elements in contact
AssigneePatek Philippe SA Geneve
InventorJulien Perret
Life of this patent
Estimating the term…
Abstract
Disclosed is a timepiece assembly including at least two elements in contact and mobile relative to each other, one of the elements having at least a first contact surface intended to rub against at least a second contact surface of the other element under dry lubrication conditions. At least one of the first and second contact surfaces is covered with a hydrophobic coating having an angle of contact with water greater than 90°, preferably greater than 100° and preferably greater than 110°, and a coefficient of friction lower than 0.15, preferably lower than 0.12 and preferably lower than 0.1, the variation in the coefficient of friction as a function of the relative humidity being lower than 25%, preferably lower than 10% and preferably lower than 5%.
Claims20
A timepiece assembly comprising at least two elements in contact and mobile relative to each other, one of said elements having at least a first contact surface intended to rub against at least a second contact surface of the other element under dry lubrication conditions, wherein at least one of said first and second contact surfaces is covered with a hydrophobic coating having an angle of contact with water greater than 90°, and a coefficient of friction lower than 0.15, the variation in said coefficient of friction as a function of the relative humidity being lower than 25%,
- wherein the hydrophobic coating is bonded to one of said first and second contact surfaces at least by covalent bonds,
- wherein said one of the first and second contact surfaces comprises active —OH sites at a density greater than 1014 OH sites/cm2, the second contact surface having subjected, prior to the deposition of the hydrophobic coating, to a surface hydroxylation treatment.
A timepiece assembly comprising at least two elements in contact and mobile relative to each other, one of said elements having at least a first contact surface intended to rub against at least a second contact surface of the other element under dry lubrication conditions, wherein at least one of said first and second contact surfaces is covered with a hydrophobic coating having an angle of contact with water greater than 90°, and a coefficient of friction lower than 0.15, the variation in said coefficient of friction as a function of the relative humidity being lower than 25%,
- wherein the hydrophobic coating is bonded to one of said first and second contact surfaces at least by covalent bonds,
- wherein the hydrophobic coating comprises at least a first layer formed by at least one assembly of molecules comprising a head, a separation chain and a terminal group, at least a part of the heads of the molecules being bonded to said one of the first and second contact surfaces by covalent bonds, and the separation chains being arranged substantially parallel to each other and orientated substantially perpendicular to said one of the first and second contact surfaces, and
- wherein the hydrophobic coating comprises at least a first layer and a second layer, the terminal group of the molecules of the first layer being a linkage group between the first layer and the second layer.
A timepiece assembly comprising at least two elements in contact and mobile relative to each other, one of said elements having at least a first contact surface intended to rub against at least a second contact surface of the other element under dry lubrication conditions, wherein at least one of said first and second contact surfaces is covered with a hydrophobic coating having an angle of contact with water greater than 90°, and a coefficient of friction lower than 0.15, the variation in said coefficient of friction as a function of the relative humidity being lower than 25%,
- wherein the hydrophobic coating is bonded to one of said first and second contact surfaces at least by covalent bonds,
- wherein the hydrophobic coating comprises at least a first layer formed by at least one assembly of molecules comprising a head, a separation chain and a terminal group, at least a part of the heads of the molecules being bonded to said one of the first and second contact surfaces by covalent bonds, and the separation chains being arranged substantially parallel to each other and orientated substantially perpendicular to said one of the first and second contact surfaces, and
- wherein the hydrophobic coating comprises at least a first layer and second layer,
- wherein the second layer comprises molecules having a head bonded to the terminal group of the molecule of the first layer, a separation chain and a non-polar terminal group, the separation chains being arranged substantially parallel to each other and orientated substantially perpendicularly to said one of the first and second contact surfaces.
Dependencies are inferred from the claim text.