Hermetically sealed mount for a piezoelectric tuning fork

Claim 2

A mechanical vibrator for a timepiece comprising: a ceramic substrate having at least one bore formed therein and including at least one first metal layer formed on one surface of said substrate, and a second metal layer formed on another surface of said substrate over a substantially larger area thereof; at least one lead pin passing through the bore of said ceramic substrate and having one end electrically connected to said first metal layer while said bore is hermetically sealed; a piezoelectric vibrating element including an end portion and exciting electrodes terminating at said end portion on one surface thereof for exciting said vibrating element, said one surface of said end portion of said vibrating element being secured to said one surface of said substrate to electrically interconnect one of said exciting electrodes with said first metal layer; and an evacuated metal housing having at least one bore through which another end of said lead pin projects outwardly of said metal housing and accommodating said vibrating element and said substrate, said second metal layer of said substrate being rigidly, hermetically secured to an inner wall of said metal housing.

Claim 3

A mechanical vibrator according to claim 1, in which said first and second metal layers are formed by a printing technique.

Claim 4

A mechanical vibrator according to claim 1, in which said evacuated metal housing comprises first and second casings which are hermetically secured to each other at their flange portions by cold welding, at least one of said first and second casings having a receptacle-shape.

Claim 5

A mechanical vibrator according to claim 3, in which one of said first and second casings has a projection serving as a positioning member for said ceramic substrate.

Claim 6

A mechanical vibrator according to claim 3, in which at least one of said first and second casings has an opening hermetically closed by a transparent member.

Claim 7

A mechanical vibrator according to claim 1, in which said piezoelectric vibrating element comprises a quartz crystal.

Claim 8

A mechanical vibrator according to claim 1, in which said piezoelectric vibrating element comprises a lithium tantalate.

Claim 9

A mechanical vibrator according to claim 1, in which said piezoelectric vibrating element comprises a tuning fork having prongs extending from said end portion.

Claim 10

A mechanical vibrator according to claim 1, in which said lead pin has a through-hole formed therein which is hermetically closed after said housing has been evacuated.

Claim 11

A mechanical vibrator according to claim 1, in which said ceramic substrate has a plate form through which said bore of said substrate extends substantially perpendicular to the plane of said substrate, and said second metal layer of said substrate is bonded to the inner wall of said metal housing by a soldering metal.

Claim 12

A mechanical vibrator according to claim 1, in which the width of said metal housing gradually decreases toward another end portion of said piezoelectric vibrating element along the longitudinal axis thereof.

Claim 13

A mechanical vibrator according to claim 1, further comprising a metal plate interposed between said second metal layer of said ceramic substrate and the inner wall of said metal housing and rigidly connected thereto by a soldering metal.

Claim 14

A mechanical vibrator according to claim 11, in which said timepiece includes a base plate and an insulating plate having a printed circuit formed thereon, said insulating plate being spaced from said base plate, and said metal housing being supported by said insulating plate.

Claim 15

A mechanical vibrator according to claim 13, in which said metal housing is secured to said insulating plate by said lead pin, said lead pin being electrically connected to said printed circuit.

Claim 16

A mechanical vibrator according to claim 13, in which said metal housing is secured to said insulating plate only at a portion near said lead pin.

Claim 17

A mechanical vibrator according to claim 13, in which said metal housing is spaced from said base plate and said insulating plate by predetermined gaps, respectively.

Claim 18

A mechanical vibrator according to claim 16, further comprising a shock absorbing member disposed between said base plate and said metal housing.

Claim 19

A mechanical vibrator according to claim 16, in which said shock absorbing member is composed of an electrically conductive elastic material.

Claim 20

A mechanical vibrator according to claim 17, in which said shock absorbing member is preassembled onto an outer wall of said metal housing.

Claim 21

A mechanical vibrator according to claim 17, further comprising a second shock absorbing member disposed between said metal housing and said insulating plate.

Claim 22

A mechanical vibrator according to claim 20, in which said second shock absorbing member is composed of an electrically conductive elastic material.

Claim 23

A mechanical vibrator according to claim 21, in which said second shock absorbing member electrically interconnects said metal housing to ground.

Claim 24

A mechanical vibrator for a timepiece comprising: a ceramic substrate having first and second bores and including first metal layers separately formed on one surface of said substrate, and a second metal layer formed on another surface of said substrate over a substantially larger area thereof and insulated from said first metal layers by said ceramic substrate; first and second lead pins extending through said first and second bores of said substrate, respectively, and electrically connected to said first metal layers by soldering by which said bores are hermetically sealed, said first and second lead pins being insulated from said second metal layer; a piezoelectric vibrating element including an end portion and exciting electrodes terminating at said end portion on one surface thereof, said one surface of said end portion of said vibrating element being secured to said one surface of said substrate by brazing by which said exciting electrodes are electrically interconnected with said first metal layers; and an evacuated metal housing accommodating said vibrating element and said substrate and including first and second casings having outwardly extending flange portions, said second casing having first and second bores through which said first and second lead pins project outwardly of said metal housing, said second metal layer of said substrate being hermetically soldered to an inner wall of said second casing, and said flange portions being secured to each other by cold welding.

Claim 25

A mechanical vibrator for a timepiece comprising: a ceramic substrate having first and second bores and including first metal layers separately formed on one surface of said substrate, and a second metal layer formed on another surface of said substrate over a substantially larger area thereof and insulated from said first metal layers by said ceramic substrate; first and second lead pins extending through said first and second bores of said substrate, respectively, and electrically connected to said first metal layers by soldering by which said bores are hermetically sealed, said first and second lead pins being insulated from said second metal layer; a piezoelectric vibrating element including an end portion and exciting electrodes terminating at said end portion on one surface thereof, said one surface of said end portion of said vibrating element being secured to said one surface of said substrate by brazing by which said exciting electrodes are electrically interconnected with said first metal layers; and an evacuated metal housing accommodating said vibrating element and said substrate and including first and second casings having outwardly extending flange portions, said second casing having first and second bores through which said first and second lead pins project outwardly of said metal housing, said second metal layer of said substrate being hermetically soldered to an inner wall of said second casing, and said flange portions being secured to each other by cold welding.

Claim 26

A mechanical vibrator for a timepiece comprising: an evacuated housing; a supporting substrate including first metal layers separately formed on one side of said vibrating element, and a second metal layer formed on another surface thereof over a substantially larger area thereof, said supporting substrate having a pair of recesses and being rigidly secured to an inner wall of said evacuated housing; lead pins having heads accommodated in said recesses, respectively, and a piezoelectric vibrating element including an end portion and exciting electrodes terminating at said end portion, the end portion of said vibrating element being superposed on said supporting substrate to cover the heads of said lead pins.

Claim 27

A mechanical vibrator for a timepiece comprising: an evacuated housing; a supporting substrate including first metal layers separately formed on one side of said vibrating element, and a second metal layer formed on another surface thereof over a substantially larger area thereof, said supporting substrate having a pair of recesses and being rigidly secured to an inner wall of said evacuated housing; lead pins having heads accommodated in said recesses, respectively, and a piezoelectric vibrating element including an end portion and exciting electrodes terminating at said end portion, the end portion of said vibrating element being superposed on said supporting substrate to cover the heads of said lead pins.

Claim 28

A mechanical vibrator according to claim 24, in which each of said recesses has an annular shoulder formed with a metal layer connected to each of said exciting electrodes by a soldering metal bonding said piezoelectric vibrating element and said supporting substrate to each other.

Claim 29

A mechanical vibrator according to claim 24, in which said supporting substrate has a pair of annular projections extending transversely to the plane of said supporting substrate and adapted to be accommodated in bores of said evacuated housing.