Time difference correction mechanism and timepiece with time difference correction mechanism

Patent metadata

Field	Value
Publication number	US-12032333-B2
Application number	US-201917420372-A
Country	US
Kind code	B2
Filing date	Dec 6, 2019
Priority date	Jan 7, 2019
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

A time difference correction mechanism includes a cylinder index star wheel that includes teeth and is connected to an hour hand, a cylinder index gear that includes teeth and is connected to a minute hand, the cylinder index gear provided radially outward of the cylinder index star wheel on a same plane as the teeth, a cylinder index lever disposed in the cylinder index gear on a same plane as the cylinder index gear, and a cylinder index spring disposed in the cylinder index gear on the same plane as the cylinder index gear. The cylinder index lever is movable between an engaged position where a claw engages with at least one of the teeth and a disengaged position where the claw disengages with the at least one of the teeth . The cylinder index spring is configured to bias the cylinder index lever to the engaged position.

First claim

The invention claimed is:

1. A time difference correction mechanism, comprising:
a cylinder index star wheel that comprises teeth on an outer circumference thereof and is configured to connect to an hour hand;
a cylinder index gear that comprises a bearing hole within a body of the cylinder index gear and teeth on an outer circumference of the cylinder index gear and is configured to connect to a minute hand, the cylinder index gear provided radially outward of the cylinder index star wheel and disposed on a same plane as the teeth of the cylinder index star wheel and coaxially with the cylinder index star wheel;
a cylinder index lever that is disposed in the cylinder index gear and on a same plane as the cylinder index gear, the cylinder index lever comprising a first end with a claw and a second end opposite the first end with a rotation supported portion having an axis and configured to be received by the bearing hole such that the cylinder index lever is rotatably coupled with the cylinder index gear; and
a cylinder index spring that is disposed in the cylinder index gear and on the same plane as the cylinder index gear,
wherein the cylinder index lever is configured to be movable rotatable about its axis between an engaged position where the claw of the cylinder index lever engages with at least one of the teeth of the cylinder index star wheel and a disengaged position where the claw disengages with the at least one of the teeth of the cylinder index star wheel,
wherein the cylinder index spring is configured to bias the cylinder index lever to the engaged position, and
wherein a change of a position of the cylinder index lever in a direction of the axis is restricted by support portions that sandwich the cylinder index lever in the direction of the axis,
wherein the cylinder index lever is formed independently from the cylinder index gear.

2. The time difference correction mechanism according to claim 1 , wherein a contour of the claw is formed by two lines and each of the two lines has a contour that curves relative to the teeth of the cylinder index star wheel at a location before an intersection of the two lines.

3. The time difference correction mechanism according to claim 1 , wherein the cylinder index spring is formed independently from the cylinder index gear.

4. The time difference correction mechanism according to claim 3 , wherein a fixed end of the cylinder index spring is fitted into the cylinder index gear and fixed thereto.

5. A time difference correction mechanism comprising:
a cylinder index star wheel that comprises teeth on an outer circumference thereof and is configured to connect to an hour hand;
a cylinder index gear that comprises a bearing hole within a body of the cylinder index gear and teeth on an outer circumference of the cylinder index gear and is configured to connect to a minute hand, the cylinder index gear provided radially outward of the cylinder index star wheel and disposed on a same plane as the teeth of the cylinder index star wheel and coaxially with the cylinder index star wheel; and
a cylinder index lever that is disposed in the cylinder index gear and on a same plane as the cylinder index gear,
wherein the cylinder index lever comprises a lever portion and a spring portion integrally formed with each other, wherein the lever portion comprises a first end with a claw and a second end opposite the first end with a rotation supported portion configured to be received by the bearing hole;
wherein the spring portion comprises a first end integral with the claw of the lever portion and a second end opposite the first end with a spring sliding portion placed relative to an inner edge of a recess in the cylinder index gear,
wherein the cylinder index lever is configured to be rotatable about its axis between an engaged position where the claw of the lever portion engages with at least one of the teeth of the cylinder index star wheel and a disengaged position where the claw disengages with the at least one of the teeth of the cylinder index star wheel,
wherein the spring portion is configured to bias the lever portion to the engaged position, and
wherein a change of a position of the cylinder index lever in a direction of the axis is restricted by support portions that sandwich the cylinder index lever in the direction of the axis.

6. The time difference correction mechanism according to claim 5 , wherein an end of the cylinder index spring is a sliding portion that is movable with respect to the cylinder index gear.

7. A timepiece comprising:
the time difference correction mechanism according to claim 1 , the hour hand, and the minute hand;
wherein the hour hand is connected to the cylinder index star wheel of the time difference correction mechanism; and
wherein the minute hand is connected to the cylinder index gear of the time difference correction mechanism.

8. The time difference correction mechanism according to claim 1 , wherein the rotation supported portion comprises an outer circumferential edge that is formed in an arc shape.

9. The time difference correction mechanism according to claim 5 , wherein the rotation supported portion comprises an outer circumferential edge that is formed in an arc shape.

10. A timepiece comprising:
the time difference correction mechanism according to claim 5 , the hour hand, and the minute hand;
wherein the hour hand is connected to the cylinder index star wheel of the time difference correction mechanism; and
wherein the minute hand is connected to the cylinder index gear of the time difference correction mechanism.

Assignees

• Citizen Watch Co Ltd

Inventors

• Morita Shoichiro
• Imamura Kazuya

Classifications

• G04B15/14

  Component parts or constructional details, e.g. construction of the lever or the escape wheel {(assembly and manufacture of the spring G04B1/145; assembly and manufacture of components, e.g. pinions, spindles G04B13/02; lubrication of clockwork bearings G04B31/008; oils for clockwork bearings in general G04B31/08)} · CPC title

• G04B13/02

  Wheels; Pinions; Spindles; Pivots (bearings G04B31/00 {; chain wheels, spindles for chain wheels, also chains and driving weights G04B1/08}) · CPC title

• G04B19/221

  mechanisms for correcting the hours hand only, i.e. independently for minutes and seconds hands · CPC title

• G04B15/04 Primary

  Cylinder escapements · CPC title

• G04B27/005 Primary

  stepwise or on determined values (G04B27/02 takes precedence) · CPC title