US 6,422,739 B1 · Mainspring device, timepiece, and method of controlling the mainspring device and the timepiece

Abstract

A timepiece, whose hands move by mechanical energy of a mainspring transmitted through a wheel train, includes a winding-up portion for accumulating energy in the mainspring, an addition and subtraction wheel train driven by addition and subtraction of accumulated energy corresponding to an amount by which the mainspring is wound up and unwound, respectively, an addition and subtraction wheel, disposed in the addition and subtraction wheel train, that rotates in correspondence with an amount by which the mainspring is wound up and unwound, and a lock mechanism actuated in response to the rotation of the addition and subtraction wheel to limit winding up and unwinding of the mainspring to a selected range of windings of the mainspring. This controls the torque output by the mainspring to a fixed range. The addition and subtraction wheel train allows efficient use of space, and can be incorporated in a watch.

Claims67

Dependent claims

A mainspring device that drives a primary wheel train by mechanical energy of a mainspring, comprising:

a winding-up portion that accumulates energy in said mainspring;
an addition-and-subtraction wheel train driven by addition and subtraction of accumulated energy corresponding to an amount by which the mainspring is wound up and unwound, respectively;
an addition-and-subtraction wheel, disposed in said addition-and-subtraction wheel train, that rotates in correspondence with an amount by which said mainspring is wound up and unwound, said addition-and-subtraction wheel having a single plane of rotation;
and
a lock mechanism actuated in response to the rotation of said addition-and-subtraction wheel to limit winding up and unwinding of said mainspring to a selected range of windings, and to thereby prevent transmission of torque having a value outside a set range from said mainspring to said primary wheel train.

2 more elements

An electronic control type mechanical timepiece comprising:

a mainspring that accumulates energy through actuation of a winding-up portion;
a generator for converting mechanical energy of the mainspring transmitted through a primary wheel train into electrical energy;
a hand connected to the primary wheel train;
an addition-and-subtraction wheel train driven by addition and subtraction of accumulated energy corresponding to an amount by which the mainspring is wound up and unwound, respectively;
an addition-and-subtraction wheel, disposed in said addition-and-subtraction wheel train, that rotates in correspondence with an amount by which the mainspring is wound up and unwound, said addition-and-subtraction wheel having a single plane of rotation and being rotatable about a stationary axis;
and
one of a winding-up lock mechanism that locks said winding-up portion to stop the winding up of said mainspring when said mainspring is wound up to a number of windings that is equal to or greater than a first predetermined number of windings, and an unwinding lock mechanism that locks the primary wheel train to stop hand movement when said mainspring is unwound to a number of windings that is equal to or less than a second predetermined number of windings.

4 more elements

Dependencies are inferred from the claim text.

Mainspring device, timepiece, and method of controlling the mainspring device and the timepiece

Life of this patent

Mainspring device, timepiece, and method of controlling the mainspring device and the timepiece

Life of this patent

Abstract

Claims67